WorldWideScience

Sample records for analysis increases accuracy

  1. Increasing Accuracy in Environmental Measurements

    Science.gov (United States)

    Jacksier, Tracey; Fernandes, Adelino; Matthew, Matt; Lehmann, Horst

    2016-04-01

    Human activity is increasing the concentrations of green house gases (GHG) in the atmosphere which results in temperature increases. High precision is a key requirement of atmospheric measurements to study the global carbon cycle and its effect on climate change. Natural air containing stable isotopes are used in GHG monitoring to calibrate analytical equipment. This presentation will examine the natural air and isotopic mixture preparation process, for both molecular and isotopic concentrations, for a range of components and delta values. The role of precisely characterized source material will be presented. Analysis of individual cylinders within multiple batches will be presented to demonstrate the ability to dynamically fill multiple cylinders containing identical compositions without isotopic fractionation. Additional emphasis will focus on the ability to adjust isotope ratios to more closely bracket sample types without the reliance on combusting naturally occurring materials, thereby improving analytical accuracy.

  2. Reporting Data with "Over-the-Counter" Data Analysis Supports Increases Educators' Analysis Accuracy

    Science.gov (United States)

    Rankin, Jenny Grant

    2013-01-01

    There is extensive research on the benefits of making data-informed decisions to improve learning, but these benefits rely on the data being effectively interpreted. Despite educators' above-average intellect and education levels, there is evidence many educators routinely misinterpret student data. Data analysis problems persist even at…

  3. Identifying the source of farmed escaped Atlantic salmon (Salmo salar): Bayesian clustering analysis increases accuracy of assignment

    DEFF Research Database (Denmark)

    Glover, Kevin A.; Hansen, Michael Møller; Skaala, Oystein

    2009-01-01

    . Accuracy of assignment varied greatly among the individual samples. For the Bayesian clustered data set consisting of five genetic groups, overall accuracy of self-assignment was 99%, demonstrating the effectiveness of this strategy to significantly increase accuracy of assignment, albeit at the expense....... Performing self-assignment simulations with the data divided into different sub-sets, overall accuracy of assignment was 44% within the entire material (44 samples), 44% for the 28 spring samples, 59% for the 16 autumn samples, and 70% for 8 autumn samples collected from a geographically restricted area...

  4. Increasing the Accuracy of Mapping Urban Forest Carbon Density by Combining Spatial Modeling and Spectral Unmixing Analysis

    Directory of Open Access Journals (Sweden)

    Hua Sun

    2015-11-01

    Full Text Available Accurately mapping urban vegetation carbon density is challenging because of complex landscapes and mixed pixels. In this study, a novel methodology was proposed that combines a linear spectral unmixing analysis (LSUA with a linear stepwise regression (LSR, a logistic model-based stepwise regression (LMSR and k-Nearest Neighbors (kNN, to map the forest carbon density of Shenzhen City of China, using Landsat 8 imagery and sample plot data collected in 2014. The independent variables that contributed to statistically significantly improving the fit of a model to data and reducing the sum of squared errors were first selected from a total of 284 spectral variables derived from the image bands. The vegetation fraction from LSUA was then added as an independent variable. The results obtained using cross-validation showed that: (1 Compared to the methods without the vegetation information, adding the vegetation fraction increased the accuracy of mapping carbon density by 1%–9.3%; (2 As the observed values increased, the LSR and kNN residuals showed overestimates and underestimates for the smaller and larger observations, respectively, while LMSR improved the systematical over and underestimations; (3 LSR resulted in illogically negative and unreasonably large estimates, while KNN produced the greatest values of root mean square error (RMSE. The results indicate that combining the spatial modeling method LMSR and the spectral unmixing analysis LUSA, coupled with Landsat imagery, is most promising for increasing the accuracy of urban forest carbon density maps. In addition, this method has considerable potential for accurate, rapid and nondestructive prediction of urban and peri-urban forest carbon stocks with an acceptable level of error and low cost.

  5. Joint analysis of psychiatric disorders increases accuracy of risk prediction for schizophrenia, bipolar disorder, and major depressive disorder

    DEFF Research Database (Denmark)

    Maier, Robert; Moser, Gerhard; Chen, Guo-Bo;

    2015-01-01

    could be further improved. The gain in prediction accuracy of the multivariate approach is equivalent to an increase in sample size of 34% for schizophrenia, 68% for bipolar disorder, and 76% for major depressive disorders using single trait models. Because our approach can be readily applied to any...... prediction is low. Here we use a multivariate linear mixed model and apply multi-trait genomic best linear unbiased prediction for genetic risk prediction. This method exploits correlations between disorders and simultaneously evaluates individual risk for each disorder. We show that the multivariate...... approach significantly increases the prediction accuracy for schizophrenia, bipolar disorder, and major depressive disorder in the discovery as well as in independent validation datasets. By grouping SNPs based on genome annotation and fitting multiple random effects, we show that the prediction accuracy...

  6. Joint Analysis of Psychiatric Disorders Increases Accuracy of Risk Prediction for Schizophrenia, Bipolar Disorder, and Major Depressive Disorder

    Science.gov (United States)

    Maier, Robert; Moser, Gerhard; Chen, Guo-Bo; Ripke, Stephan; Absher, Devin; Agartz, Ingrid; Akil, Huda; Amin, Farooq; Andreassen, Ole A.; Anjorin, Adebayo; Anney, Richard; Arking, Dan E.; Asherson, Philip; Azevedo, Maria H.; Backlund, Lena; Badner, Judith A.; Bailey, Anthony J.; Banaschewski, Tobias; Barchas, Jack D.; Barnes, Michael R.; Barrett, Thomas B.; Bass, Nicholas; Battaglia, Agatino; Bauer, Michael; Bayés, Mònica; Bellivier, Frank; Bergen, Sarah E.; Berrettini, Wade; Betancur, Catalina; Bettecken, Thomas; Biederman, Joseph; Binder, Elisabeth B.; Black, Donald W.; Blackwood, Douglas H.R.; Bloss, Cinnamon S.; Boehnke, Michael; Boomsma, Dorret I.; Breen, Gerome; Breuer, René; Bruggeman, Richard; Buccola, Nancy G.; Buitelaar, Jan K.; Bunney, William E.; Buxbaum, Joseph D.; Byerley, William F.; Caesar, Sian; Cahn, Wiepke; Cantor, Rita M.; Casas, Miguel; Chakravarti, Aravinda; Chambert, Kimberly; Choudhury, Khalid; Cichon, Sven; Cloninger, C. Robert; Collier, David A.; Cook, Edwin H.; Coon, Hilary; Cormand, Bru; Cormican, Paul; Corvin, Aiden; Coryell, William H.; Craddock, Nicholas; Craig, David W.; Craig, Ian W.; Crosbie, Jennifer; Cuccaro, Michael L.; Curtis, David; Czamara, Darina; Daly, Mark J.; Datta, Susmita; Dawson, Geraldine; Day, Richard; De Geus, Eco J.; Degenhardt, Franziska; Devlin, Bernie; Djurovic, Srdjan; Donohoe, Gary J.; Doyle, Alysa E.; Duan, Jubao; Dudbridge, Frank; Duketis, Eftichia; Ebstein, Richard P.; Edenberg, Howard J.; Elia, Josephine; Ennis, Sean; Etain, Bruno; Fanous, Ayman; Faraone, Stephen V.; Farmer, Anne E.; Ferrier, I. Nicol; Flickinger, Matthew; Fombonne, Eric; Foroud, Tatiana; Frank, Josef; Franke, Barbara; Fraser, Christine; Freedman, Robert; Freimer, Nelson B.; Freitag, Christine M.; Friedl, Marion; Frisén, Louise; Gallagher, Louise; Gejman, Pablo V.; Georgieva, Lyudmila; Gershon, Elliot S.; Geschwind, Daniel H.; Giegling, Ina; Gill, Michael; Gordon, Scott D.; Gordon-Smith, Katherine; Green, Elaine K.; Greenwood, Tiffany A.; Grice, Dorothy E.; Gross, Magdalena; Grozeva, Detelina; Guan, Weihua; Gurling, Hugh; De Haan, Lieuwe; Haines, Jonathan L.; Hakonarson, Hakon; Hallmayer, Joachim; Hamilton, Steven P.; Hamshere, Marian L.; Hansen, Thomas F.; Hartmann, Annette M.; Hautzinger, Martin; Heath, Andrew C.; Henders, Anjali K.; Herms, Stefan; Hickie, Ian B.; Hipolito, Maria; Hoefels, Susanne; Holmans, Peter A.; Holsboer, Florian; Hoogendijk, Witte J.; Hottenga, Jouke-Jan; Hultman, Christina M.; Hus, Vanessa; Ingason, Andrés; Ising, Marcus; Jamain, Stéphane; Jones, Ian; Jones, Lisa; Kähler, Anna K.; Kahn, René S.; Kandaswamy, Radhika; Keller, Matthew C.; Kelsoe, John R.; Kendler, Kenneth S.; Kennedy, James L.; Kenny, Elaine; Kent, Lindsey; Kim, Yunjung; Kirov, George K.; Klauck, Sabine M.; Klei, Lambertus; Knowles, James A.; Kohli, Martin A.; Koller, Daniel L.; Konte, Bettina; Korszun, Ania; Krabbendam, Lydia; Krasucki, Robert; Kuntsi, Jonna; Kwan, Phoenix; Landén, Mikael; Långström, Niklas; Lathrop, Mark; Lawrence, Jacob; Lawson, William B.; Leboyer, Marion; Ledbetter, David H.; Lee, Phil H.; Lencz, Todd; Lesch, Klaus-Peter; Levinson, Douglas F.; Lewis, Cathryn M.; Li, Jun; Lichtenstein, Paul; Lieberman, Jeffrey A.; Lin, Dan-Yu; Linszen, Don H.; Liu, Chunyu; Lohoff, Falk W.; Loo, Sandra K.; Lord, Catherine; Lowe, Jennifer K.; Lucae, Susanne; MacIntyre, Donald J.; Madden, Pamela A.F.; Maestrini, Elena; Magnusson, Patrik K.E.; Mahon, Pamela B.; Maier, Wolfgang; Malhotra, Anil K.; Mane, Shrikant M.; Martin, Christa L.; Martin, Nicholas G.; Mattheisen, Manuel; Matthews, Keith; Mattingsdal, Morten; McCarroll, Steven A.; McGhee, Kevin A.; McGough, James J.; McGrath, Patrick J.; McGuffin, Peter; McInnis, Melvin G.; McIntosh, Andrew; McKinney, Rebecca; McLean, Alan W.; McMahon, Francis J.; McMahon, William M.; McQuillin, Andrew; Medeiros, Helena; Medland, Sarah E.; Meier, Sandra; Melle, Ingrid; Meng, Fan; Meyer, Jobst; Middeldorp, Christel M.; Middleton, Lefkos; Milanova, Vihra; Miranda, Ana; Monaco, Anthony P.; Montgomery, Grant W.; Moran, Jennifer L.; Moreno-De-Luca, Daniel; Morken, Gunnar; Morris, Derek W.; Morrow, Eric M.; Moskvina, Valentina; Mowry, Bryan J.; Muglia, Pierandrea; Mühleisen, Thomas W.; Müller-Myhsok, Bertram; Murtha, Michael; Myers, Richard M.; Myin-Germeys, Inez; Neale, Benjamin M.; Nelson, Stan F.; Nievergelt, Caroline M.; Nikolov, Ivan; Nimgaonkar, Vishwajit; Nolen, Willem A.; Nöthen, Markus M.; Nurnberger, John I.

    2015-01-01

    Genetic risk prediction has several potential applications in medical research and clinical practice and could be used, for example, to stratify a heterogeneous population of patients by their predicted genetic risk. However, for polygenic traits, such as psychiatric disorders, the accuracy of risk prediction is low. Here we use a multivariate linear mixed model and apply multi-trait genomic best linear unbiased prediction for genetic risk prediction. This method exploits correlations between disorders and simultaneously evaluates individual risk for each disorder. We show that the multivariate approach significantly increases the prediction accuracy for schizophrenia, bipolar disorder, and major depressive disorder in the discovery as well as in independent validation datasets. By grouping SNPs based on genome annotation and fitting multiple random effects, we show that the prediction accuracy could be further improved. The gain in prediction accuracy of the multivariate approach is equivalent to an increase in sample size of 34% for schizophrenia, 68% for bipolar disorder, and 76% for major depressive disorders using single trait models. Because our approach can be readily applied to any number of GWAS datasets of correlated traits, it is a flexible and powerful tool to maximize prediction accuracy. With current sample size, risk predictors are not useful in a clinical setting but already are a valuable research tool, for example in experimental designs comparing cases with high and low polygenic risk. PMID:25640677

  7. Final Technical Report: Increasing Prediction Accuracy.

    Energy Technology Data Exchange (ETDEWEB)

    King, Bruce Hardison [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hansen, Clifford [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Stein, Joshua [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-12-01

    PV performance models are used to quantify the value of PV plants in a given location. They combine the performance characteristics of the system, the measured or predicted irradiance and weather at a site, and the system configuration and design into a prediction of the amount of energy that will be produced by a PV system. These predictions must be as accurate as possible in order for finance charges to be minimized. Higher accuracy equals lower project risk. The Increasing Prediction Accuracy project at Sandia focuses on quantifying and reducing uncertainties in PV system performance models.

  8. Joint analysis of psychiatric disorders increases accuracy of risk prediction for schizophrenia, bipolar disorder, and major depressive disorder

    OpenAIRE

    Maier, R.; Moser, G.; Chen, G. B.; Ripke, S; Cross-Disorder Working Group of the Psychiatric Genomics Consortium; Coryell, W.; Potash, J. B.; Scheftner, W.A.; J. Shi; Weissman, M. M.; Hultman, C. M.; Landén, M; Levinson, D.F.; Kendler, K. S.; Smoller, J.W.

    2015-01-01

    Cross-Disorder Working Group of the Psychiatric Genomics Consortium - Vicente A.M. Acessível em: http://www.ncbi.nlm.nih.gov/pmc/articles/pmid/25640677/ Genetic risk prediction has several potential applications in medical research and clinical practice and could be used, for example, to stratify a heterogeneous population of patients by their predicted genetic risk. However, for polygenic traits, such as psychiatric disorders, the accuracy of risk prediction is low. Here we use a multi...

  9. Strategies to Increase Accuracy in Text Classification

    NARCIS (Netherlands)

    Blommesteijn, D.

    2014-01-01

    Text classification via supervised learning involves various steps from processing raw data, features extraction to training and validating classifiers. Within these steps implementation decisions are critical to the resulting classifier accuracy. This paper contains a report of the study performed

  10. Increasing of AC compensation method accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Havlicek, V. E-mail: havlicek@fel.cvut.cz; Pokorny, M

    2003-01-01

    The original MMF compensation method allows the magnetic properties of single sheets and strips to be measured in the same way as the closed specimen properties. The accuracy of the method is limited due to the finite gain of the feedback loop fulfilling the condition of its stability. Digitalisation of the compensation loop appropriate processing of the error signal can rapidly improve the accuracy. The basic ideas of this new approach and the experimental results are described in this paper.

  11. Diagnostic accuracy of deep vein thrombosis is increased by analysis using combined optimal cut-off values of postoperative plasma D-dimer levels

    Science.gov (United States)

    JIANG, YONG; LI, JIE; LIU, YANG; ZHANG, WEIGUO

    2016-01-01

    The present study aimed to evaluate the accuracy of analysis using optimal cut-off values of plasma D-dimer levels in the diagnosis of deep vein thrombosis (DVT). A total of 175 orthopedic patients with DVT and 162 patients without DVT were included in the study. Ultrasonic color Doppler imaging was performed on lower limb veins prior to and following orthopedic surgery in order to determine the types of orthopedic conditions that were present. An enzyme-linked fluorescent assay was performed to detect the expression levels of D-dimer in plasma, and receiver operating characteristic analysis was performed to predict the occurrence of DVT on the basis of the expression levels of D-dimer. After surgery, the expression levels of D-dimer in the plasma of DVT patients were significantly higher in comparison with those in orthopedic patients without DVT (P<0.05). When the patients were divided into subgroups according to the underlying orthopedic condition, the expression levels of D-dimer in the plasma of each subgroup were higher 1 day after orthopedic surgery in comparison to those prior to surgery (P<0.05). The diagnostic accuracy achieved using combined optimal cut-off values at 1 and 3 days post-surgery was significantly higher than the accuracy when using a single optimal cut-off value (P<0.05). In conclusion, detection of D-dimer expression levels at 1 day post-orthopedic surgery may be important in predicting DVT. In addition, the diagnostic accuracy of DVT is significantly increased by analysis using combined optimal cut-off values of D-dimer plasma expression levels. PMID:27168793

  12. Immunohistochemical Ki-67/KL1 double stains increase accuracy of Ki-67 indices in breast cancer and simplify automated image analysis

    DEFF Research Database (Denmark)

    Nielsen, Patricia S; Bentzer, Nina K; Jensen, Vibeke;

    2014-01-01

    by digital image analysis. This study aims to detect the difference in accuracy and precision between manual indices of single and double stains, to develop an automated quantification of double stains, and to explore the relation between automated indices and tumor characteristics when quantified...... in different regions: hot spots, global tumor areas, and invasive fronts. MATERIALS AND METHODS: Paraffin-embedded, formalin-fixed tissue from 100 consecutive patients with invasive breast cancer was immunohistochemically stained for Ki-67 and Ki-67/KL1. Ki-67 was manually scored in different regions by 2...

  13. Increased accuracy of ligand sensing by receptor internalization

    CERN Document Server

    Aquino, Gerardo

    2010-01-01

    Many types of cells can sense external ligand concentrations with cell-surface receptors at extremely high accuracy. Interestingly, ligand-bound receptors are often internalized, a process also known as receptor-mediated endocytosis. While internalization is involved in a vast number of important functions for the life of a cell, it was recently also suggested to increase the accuracy of sensing ligand as the overcounting of the same ligand molecules is reduced. Here we show, by extending simple ligand-receptor models to out-of-equilibrium thermodynamics, that internalization increases the accuracy with which cells can measure ligand concentrations in the external environment. Comparison with experimental rates of real receptors demonstrates that our model has indeed biological significance.

  14. Modeling Linkage Disequilibrium Increases Accuracy of Polygenic Risk Scores

    DEFF Research Database (Denmark)

    Vilhjálmsson, Bjarni J; Yang, Jian; Finucane, Hilary K;

    2015-01-01

    outperforms the approach of pruning followed by thresholding, particularly at large sample sizes. Accordingly, predicted R(2) increased from 20.1% to 25.3% in a large schizophrenia dataset and from 9.8% to 12.0% in a large multiple sclerosis dataset. A similar relative improvement in accuracy was observed...... for three additional large disease datasets and for non-European schizophrenia samples. The advantage of LDpred over existing methods will grow as sample sizes increase....

  15. Accuracy analysis of distributed simulation systems

    Science.gov (United States)

    Lin, Qi; Guo, Jing

    2010-08-01

    Existed simulation works always emphasize on procedural verification, which put too much focus on the simulation models instead of simulation itself. As a result, researches on improving simulation accuracy are always limited in individual aspects. As accuracy is the key in simulation credibility assessment and fidelity study, it is important to give an all-round discussion of the accuracy of distributed simulation systems themselves. First, the major elements of distributed simulation systems are summarized, which can be used as the specific basis of definition, classification and description of accuracy of distributed simulation systems. In Part 2, the framework of accuracy of distributed simulation systems is presented in a comprehensive way, which makes it more sensible to analyze and assess the uncertainty of distributed simulation systems. The concept of accuracy of distributed simulation systems is divided into 4 other factors and analyzed respectively further more in Part 3. In Part 4, based on the formalized description of framework of accuracy analysis in distributed simulation systems, the practical approach are put forward, which can be applied to study unexpected or inaccurate simulation results. Following this, a real distributed simulation system based on HLA is taken as an example to verify the usefulness of the approach proposed. The results show that the method works well and is applicable in accuracy analysis of distributed simulation systems.

  16. Modeling Linkage Disequilibrium Increases Accuracy of Polygenic Risk Scores

    Science.gov (United States)

    Vilhjálmsson, Bjarni J.; Yang, Jian; Finucane, Hilary K.; Gusev, Alexander; Lindström, Sara; Ripke, Stephan; Genovese, Giulio; Loh, Po-Ru; Bhatia, Gaurav; Do, Ron; Hayeck, Tristan; Won, Hong-Hee; Ripke, Stephan; Neale, Benjamin M.; Corvin, Aiden; Walters, James T.R.; Farh, Kai-How; Holmans, Peter A.; Lee, Phil; Bulik-Sullivan, Brendan; Collier, David A.; Huang, Hailiang; Pers, Tune H.; Agartz, Ingrid; Agerbo, Esben; Albus, Margot; Alexander, Madeline; Amin, Farooq; Bacanu, Silviu A.; Begemann, Martin; Belliveau, Richard A.; Bene, Judit; Bergen, Sarah E.; Bevilacqua, Elizabeth; Bigdeli, Tim B.; Black, Donald W.; Bruggeman, Richard; Buccola, Nancy G.; Buckner, Randy L.; Byerley, William; Cahn, Wiepke; Cai, Guiqing; Campion, Dominique; Cantor, Rita M.; Carr, Vaughan J.; Carrera, Noa; Catts, Stanley V.; Chambert, Kimberly D.; Chan, Raymond C.K.; Chen, Ronald Y.L.; Chen, Eric Y.H.; Cheng, Wei; Cheung, Eric F.C.; Chong, Siow Ann; Cloninger, C. Robert; Cohen, David; Cohen, Nadine; Cormican, Paul; Craddock, Nick; Crowley, James J.; Curtis, David; Davidson, Michael; Davis, Kenneth L.; Degenhardt, Franziska; Del Favero, Jurgen; DeLisi, Lynn E.; Demontis, Ditte; Dikeos, Dimitris; Dinan, Timothy; Djurovic, Srdjan; Donohoe, Gary; Drapeau, Elodie; Duan, Jubao; Dudbridge, Frank; Durmishi, Naser; Eichhammer, Peter; Eriksson, Johan; Escott-Price, Valentina; Essioux, Laurent; Fanous, Ayman H.; Farrell, Martilias S.; Frank, Josef; Franke, Lude; Freedman, Robert; Freimer, Nelson B.; Friedl, Marion; Friedman, Joseph I.; Fromer, Menachem; Genovese, Giulio; Georgieva, Lyudmila; Gershon, Elliot S.; Giegling, Ina; Giusti-Rodrguez, Paola; Godard, Stephanie; Goldstein, Jacqueline I.; Golimbet, Vera; Gopal, Srihari; Gratten, Jacob; Grove, Jakob; de Haan, Lieuwe; Hammer, Christian; Hamshere, Marian L.; Hansen, Mark; Hansen, Thomas; Haroutunian, Vahram; Hartmann, Annette M.; Henskens, Frans A.; Herms, Stefan; Hirschhorn, Joel N.; Hoffmann, Per; Hofman, Andrea; Hollegaard, Mads V.; Hougaard, David M.; Ikeda, Masashi; Joa, Inge; Julia, Antonio; Kahn, Rene S.; Kalaydjieva, Luba; Karachanak-Yankova, Sena; Karjalainen, Juha; Kavanagh, David; Keller, Matthew C.; Kelly, Brian J.; Kennedy, James L.; Khrunin, Andrey; Kim, Yunjung; Klovins, Janis; Knowles, James A.; Konte, Bettina; Kucinskas, Vaidutis; Kucinskiene, Zita Ausrele; Kuzelova-Ptackova, Hana; Kahler, Anna K.; Laurent, Claudine; Keong, Jimmy Lee Chee; Lee, S. Hong; Legge, Sophie E.; Lerer, Bernard; Li, Miaoxin; Li, Tao; Liang, Kung-Yee; Lieberman, Jeffrey; Limborska, Svetlana; Loughland, Carmel M.; Lubinski, Jan; Lnnqvist, Jouko; Macek, Milan; Magnusson, Patrik K.E.; Maher, Brion S.; Maier, Wolfgang; Mallet, Jacques; Marsal, Sara; Mattheisen, Manuel; Mattingsdal, Morten; McCarley, Robert W.; McDonald, Colm; McIntosh, Andrew M.; Meier, Sandra; Meijer, Carin J.; Melegh, Bela; Melle, Ingrid; Mesholam-Gately, Raquelle I.; Metspalu, Andres; Michie, Patricia T.; Milani, Lili; Milanova, Vihra; Mokrab, Younes; Morris, Derek W.; Mors, Ole; Mortensen, Preben B.; Murphy, Kieran C.; Murray, Robin M.; Myin-Germeys, Inez; Mller-Myhsok, Bertram; Nelis, Mari; Nenadic, Igor; Nertney, Deborah A.; Nestadt, Gerald; Nicodemus, Kristin K.; Nikitina-Zake, Liene; Nisenbaum, Laura; Nordin, Annelie; O’Callaghan, Eadbhard; O’Dushlaine, Colm; O’Neill, F. Anthony; Oh, Sang-Yun; Olincy, Ann; Olsen, Line; Van Os, Jim; Pantelis, Christos; Papadimitriou, George N.; Papiol, Sergi; Parkhomenko, Elena; Pato, Michele T.; Paunio, Tiina; Pejovic-Milovancevic, Milica; Perkins, Diana O.; Pietilinen, Olli; Pimm, Jonathan; Pocklington, Andrew J.; Powell, John; Price, Alkes; Pulver, Ann E.; Purcell, Shaun M.; Quested, Digby; Rasmussen, Henrik B.; Reichenberg, Abraham; Reimers, Mark A.; Richards, Alexander L.; Roffman, Joshua L.; Roussos, Panos; Ruderfer, Douglas M.; Salomaa, Veikko; Sanders, Alan R.; Schall, Ulrich; Schubert, Christian R.; Schulze, Thomas G.; Schwab, Sibylle G.; Scolnick, Edward M.; Scott, Rodney J.; Seidman, Larry J.; Shi, Jianxin; Sigurdsson, Engilbert; Silagadze, Teimuraz; Silverman, Jeremy M.; Sim, Kang; Slominsky, Petr; Smoller, Jordan W.; So, Hon-Cheong; Spencer, Chris C.A.; Stahl, Eli A.; Stefansson, Hreinn; Steinberg, Stacy; Stogmann, Elisabeth; Straub, Richard E.; Strengman, Eric; Strohmaier, Jana; Stroup, T. Scott; Subramaniam, Mythily; Suvisaari, Jaana; Svrakic, Dragan M.; Szatkiewicz, Jin P.; Sderman, Erik; Thirumalai, Srinivas; Toncheva, Draga; Tooney, Paul A.; Tosato, Sarah; Veijola, Juha

    2015-01-01

    Polygenic risk scores have shown great promise in predicting complex disease risk and will become more accurate as training sample sizes increase. The standard approach for calculating risk scores involves linkage disequilibrium (LD)-based marker pruning and applying a p value threshold to association statistics, but this discards information and can reduce predictive accuracy. We introduce LDpred, a method that infers the posterior mean effect size of each marker by using a prior on effect sizes and LD information from an external reference panel. Theory and simulations show that LDpred outperforms the approach of pruning followed by thresholding, particularly at large sample sizes. Accordingly, predicted R2 increased from 20.1% to 25.3% in a large schizophrenia dataset and from 9.8% to 12.0% in a large multiple sclerosis dataset. A similar relative improvement in accuracy was observed for three additional large disease datasets and for non-European schizophrenia samples. The advantage of LDpred over existing methods will grow as sample sizes increase. PMID:26430803

  17. Cooperation between referees and authors increases peer review accuracy.

    Directory of Open Access Journals (Sweden)

    Jeffrey T Leek

    Full Text Available Peer review is fundamentally a cooperative process between scientists in a community who agree to review each other's work in an unbiased fashion. Peer review is the foundation for decisions concerning publication in journals, awarding of grants, and academic promotion. Here we perform a laboratory study of open and closed peer review based on an online game. We show that when reviewer behavior was made public under open review, reviewers were rewarded for refereeing and formed significantly more cooperative interactions (13% increase in cooperation, P = 0.018. We also show that referees and authors who participated in cooperative interactions had an 11% higher reviewing accuracy rate (P = 0.016. Our results suggest that increasing cooperation in the peer review process can lead to a decreased risk of reviewing errors.

  18. Using Transponders on the Moon to Increase Accuracy of GPS

    Science.gov (United States)

    Penanen, Konstantin; Chui, Talso

    2008-01-01

    It has been proposed to place laser or radio transponders at suitably chosen locations on the Moon to increase the accuracy achievable using the Global Positioning System (GPS) or other satellite-based positioning system. The accuracy of GPS position measurements depends on the accuracy of determination of the ephemerides of the GPS satellites. These ephemerides are determined by means of ranging to and from Earth-based stations and consistency checks among the satellites. Unfortunately, ranging to and from Earth is subject to errors caused by atmospheric effects, notably including unpredictable variations in refraction. The proposal is based on exploitation of the fact that ranging between a GPS satellite and another object outside the atmosphere is not subject to error-inducing atmospheric effects. The Moon is such an object and is a convenient place for a ranging station. The ephemeris of the Moon is well known and, unlike a GPS satellite, the Moon is massive enough that its orbit is not measurably affected by the solar wind and solar radiation. According to the proposal, each GPS satellite would repeatedly send a short laser or radio pulse toward the Moon and the transponder(s) would respond by sending back a pulse and delay information. The GPS satellite could then compute its distance from the known position(s) of the transponder(s) on the Moon. Because the same hemisphere of the Moon faces the Earth continuously, any transponders placed there would remain continuously or nearly continuously accessible to GPS satellites, and so only a relatively small number of transponders would be needed to provide continuous coverage. Assuming that the transponders would depend on solar power, it would be desirable to use at least two transponders, placed at diametrically opposite points on the edges of the Moon disk as seen from Earth, so that all or most of the time, at least one of them would be in sunlight.

  19. Accuracy Assessment and Analysis for GPT2

    Directory of Open Access Journals (Sweden)

    YAO Yibin

    2015-07-01

    Full Text Available GPT(global pressure and temperature is a global empirical model usually used to provide temperature and pressure for the determination of tropospheric delay, there are some weakness to GPT, these have been improved with a new empirical model named GPT2, which not only improves the accuracy of temperature and pressure, but also provides specific humidity, water vapor pressure, mapping function coefficients and other tropospheric parameters, and no accuracy analysis of GPT2 has been made until now. In this paper high-precision meteorological data from ECWMF and NOAA were used to test and analyze the accuracy of temperature, pressure and water vapor pressure expressed by GPT2, testing results show that the mean Bias of temperature is -0.59℃, average RMS is 3.82℃; absolute value of average Bias of pressure and water vapor pressure are less than 1 mb, GPT2 pressure has average RMS of 7 mb, and water vapor pressure no more than 3 mb, accuracy is different in different latitudes, all of them have obvious seasonality. In conclusion, GPT2 model has high accuracy and stability on global scale.

  20. Radioactivity analysis of food and accuracy control

    International Nuclear Information System (INIS)

    From the fact that radioactive substances have been detected from the foods such as agricultural and livestock products and marine products due to the accident of the Fukushima Daiichi Nuclear Power Station of Tokyo Electric Power Company, the Ministry of Health, Labour and Welfare stipulated new standards geared to general foods on radioactive cesium by replacing the interim standards up to now. Various institutions began to measure radioactivity on the basis of this instruction, but as a new challenge, a problem of the reliability of the data occurred. Therefore, accuracy control to indicate the proof that the quality of the data can be retained at an appropriate level judging from an objective manner is important. In order to consecutively implement quality management activities, it is necessary for each inspection agency to build an accuracy control system. This paper introduces support service, as a new attempt, for establishing the accuracy control system. This service is offered jointly by three organizations, such as TUV Rheinland Japan Ltd., Japan Frozen Foods Inspection Corporation, and Japan Chemical Analysis Center. This service consists of the training of radioactivity measurement practitioners, proficiency test for radioactive substance measurement, and personal authentication. (O.A.)

  1. HOMEWORK ACCURACY TO INCREASE THE ACADEMIC REPERTOIRE OF YOUNG CHILDREN WITH AUTISM

    Directory of Open Access Journals (Sweden)

    Lina GILIC

    2016-04-01

    Full Text Available There are many forms of interventions used to increase homework completion. However, there is far less research to assess homework accuracy for young children with special needs, and even less for young children diagnosed with Autism. Homework intervention methods have been proven by researchers to be effective under certain specific circumstances. Emphasis should be placed on increasing the accuracy of homework completed prior to deciding what intervention would be more effective for a particular student struggling with homework completion. Educators should take into consideration the level of participation from the children’s home, the needs of the student, and how data would be collected and communicated for homework accuracy. Data for visual analysis would identify the homework completed correctly rather than just completed, and also identify progress over time. Researchers have demonstrated that homework completed cannot determine academic skill gained which is needed for academic success for young students with or without disabilities. Homework accuracy requires greater attention and emphasis in the early childhood research. The need for research on young children with Autism is evident as it is the fastest growing neurobiological condition in the world. The inclusion of children with Autism in the general environment has also greatly increased. Recommendations for further research focused on homework accuracy are offered.

  2. Calculating the parameters of reactor kinetics with increased accuracy

    International Nuclear Information System (INIS)

    The procedure of reactor kinetics equation solution with high accuracy and the program realizing this procedure are described. The method is based on approximation of reactor neutron flux density and concentration of nuclei-precursors of delayed neutrons on the final time interval by the polynomial of the 3d type. This approach permits to by-pass multiple limitations of different numerical methods applied before to solve the same problem (restriction in value of a time step due to possibility of stability loss, in condition of completeness of a set of point kinetics equations, in value of the induced error on every time step). Calculations of reactor kinetics for different variants of reactivity representation are carried out

  3. Creativity in gifted identification: increasing accuracy and diversity.

    Science.gov (United States)

    Luria, Sarah R; O'Brien, Rebecca L; Kaufman, James C

    2016-08-01

    Many federal definitions and popular theories of giftedness specify creativity as a core component. Nevertheless, states rely primarily on measures of intelligence for giftedness identification. As minority and culturally diverse students continue to be underrepresented in gifted programs, it is reasonable to ask if increasing the prominence of creativity in gifted identification may help increase balance and equity. In this paper, we explore both layperson and psychometric conceptions of bias and suggest that adding creativity measures to the identification process alleviates both perceptions and the presence of bias. We recognize, however, the logistic and measurement-related challenges to including creativity assessments.

  4. Creativity in gifted identification: increasing accuracy and diversity.

    Science.gov (United States)

    Luria, Sarah R; O'Brien, Rebecca L; Kaufman, James C

    2016-08-01

    Many federal definitions and popular theories of giftedness specify creativity as a core component. Nevertheless, states rely primarily on measures of intelligence for giftedness identification. As minority and culturally diverse students continue to be underrepresented in gifted programs, it is reasonable to ask if increasing the prominence of creativity in gifted identification may help increase balance and equity. In this paper, we explore both layperson and psychometric conceptions of bias and suggest that adding creativity measures to the identification process alleviates both perceptions and the presence of bias. We recognize, however, the logistic and measurement-related challenges to including creativity assessments. PMID:27434531

  5. Surface accuracy analysis of large deployable antennas

    Science.gov (United States)

    Tang, Yaqiong; Li, Tuanjie; Wang, Zuowei; Deng, Hanqing

    2014-11-01

    This paper performs an analysis to the systematic surface figure error influenced by three factors including errors of faceted paraboloids, fabrication imperfection and random thermal strains in orbit. Firstly, the computational formulas for root-mean-square surface deviations caused by these factors are presented respectively. The stochastic finite element method is applied to derive the computational formulas of fabrication imperfection and random thermal strains, by which the sensitivity of surface accuracy to component imperfection can be revealed. Then the Monte Carlo simulation method is introduced to obtain the surface figure by sampling test on random errors. Finally, the analytical method is applied to the research on the surface figure error of AstroMesh deployable reflector. The results show that the deviations between the root-mean-square surface errors calculated by the proposed formulas with less consuming time and those by the Monte Carlo simulation method are less than 2%, which indicates that the proposed method is efficient and receivable enough to analyze systematic surface figure error of a large deployable antenna. Moreover, further investigations on the relationship between surface RMS deviation and the antenna parameters including aperture and the number of subdivisions are presented in the end.

  6. Increasing the range accuracy of three-dimensional ghost imaging ladar using optimum slicing number method

    Science.gov (United States)

    Yang, Xu; Zhang, Yong; Xu, Lu; Yang, Cheng-Hua; Wang, Qiang; Liu, Yue-Hao; Zhao, Yuan

    2015-12-01

    The range accuracy of three-dimensional (3D) ghost imaging is derived. Based on the derived range accuracy equation, the relationship between the slicing number and the range accuracy is analyzed and an optimum slicing number (OSN) is determined. According to the OSN, an improved 3D ghost imaging algorithm is proposed to increase the range accuracy. Experimental results indicate that the slicing number can affect the range accuracy significantly and the highest range accuracy can be achieved if the 3D ghost imaging system works with OSN. Project supported by the Young Scientist Fund of the National Natural Science Foundation of China (Grant No. 61108072).

  7. Increasing Assignment Completion and Accuracy Using a Daily Report Card Procedure.

    Science.gov (United States)

    Drew, Barry M.; And Others

    1982-01-01

    Examined the effects of daily report cards designed to increase the completion and accuracy of in-class assignments in two youngsters described as having a behavioral history of difficulty in completing seat work. Use of the procedure produced immediate significant changes in rates of both completion and accuracy. (Author)

  8. Deep learning as a tool for increased accuracy and efficiency of histopathological diagnosis

    Science.gov (United States)

    Litjens, Geert; Sánchez, Clara I.; Timofeeva, Nadya; Hermsen, Meyke; Nagtegaal, Iris; Kovacs, Iringo; Hulsbergen-van de Kaa, Christina; Bult, Peter; van Ginneken, Bram; van der Laak, Jeroen

    2016-05-01

    Pathologists face a substantial increase in workload and complexity of histopathologic cancer diagnosis due to the advent of personalized medicine. Therefore, diagnostic protocols have to focus equally on efficiency and accuracy. In this paper we introduce ‘deep learning’ as a technique to improve the objectivity and efficiency of histopathologic slide analysis. Through two examples, prostate cancer identification in biopsy specimens and breast cancer metastasis detection in sentinel lymph nodes, we show the potential of this new methodology to reduce the workload for pathologists, while at the same time increasing objectivity of diagnoses. We found that all slides containing prostate cancer and micro- and macro-metastases of breast cancer could be identified automatically while 30–40% of the slides containing benign and normal tissue could be excluded without the use of any additional immunohistochemical markers or human intervention. We conclude that ‘deep learning’ holds great promise to improve the efficacy of prostate cancer diagnosis and breast cancer staging.

  9. HOMEWORK ACCURACY TO INCREASE THE ACADEMIC REPERTOIRE OF YOUNG CHILDREN WITH AUTISM

    OpenAIRE

    Lina GILIC

    2016-01-01

    There are many forms of interventions used to increase homework completion. However, there is far less research to assess homework accuracy for young children with special needs, and even less for young children diagnosed with Autism. Homework intervention methods have been proven by researchers to be effective under certain specific circumstances. Emphasis should be placed on increasing the accuracy of homework completed prior to deciding what intervention would be more effective for a parti...

  10. Multimodal magnetic resonance imaging increases the overall diagnostic accuracy in brain tumours: Correlation with histopathology

    Directory of Open Access Journals (Sweden)

    Kasim Abul-Kasim

    2013-03-01

    Full Text Available Background: The aim of this retrospective study was to assess the contribution of multimodal MRI techniques, specifically perfusion-weighted imaging (PWI, and/or MR spectroscopy (MRS, in increasing the diagnostic accuracy of MRI in brain tumours.Methods: Forty-four patients with suspected brain tumours (27 (61% patients male, mean age 58±17 (mean±SD years were included in this retrospective analysis. Patients were examined with conventional MR sequences, DWI, and with PWI and/or MRS. The concordance between the diagnoses obtained with multimodal MRI and with the conventional MR sequences, and the final diagnosis obtained by biopsy, was estimated. Fisher’s exact test and/or chi-square test was performed to estimate the added utility of multimodal MRI. Statistical significance was set at p<0.05.Results: With multimodal MRI, the diagnosis in 41 (93% patients was the same as that obtained by biopsy, compared with 39% (17/44 patients when the readers were allowed to give one diagnostic possibility during the evaluation of the conventional MR sequences alone (p<0.001. The concordance between the diagnoses provided by evaluating the multimodal MRIs and the final diagnoses was almost perfect (κ value 0.92, 95% CI 0.82 - 1. PWI primarily helped to differentiate lymphomas from other solid tumours, whereas MRS helped to differentiate malignant glioma from metastasis. Both PWI and MRS helped in grading astrocytomas.Conclusion: Multimodal MRI increases diagnostic accuracy and should, wherever available, be performed in the work-up of brain tumours, although this entails increased examination cost and time.

  11. Study on Increasing the Accuracy of Classification Based on Ant Colony algorithm

    Science.gov (United States)

    Yu, M.; Chen, D.-W.; Dai, C.-Y.; Li, Z.-L.

    2013-05-01

    The application for GIS advances the ability of data analysis on remote sensing image. The classification and distill of remote sensing image is the primary information source for GIS in LUCC application. How to increase the accuracy of classification is an important content of remote sensing research. Adding features and researching new classification methods are the ways to improve accuracy of classification. Ant colony algorithm based on mode framework defined, agents of the algorithms in nature-inspired computation field can show a kind of uniform intelligent computation mode. It is applied in remote sensing image classification is a new method of preliminary swarm intelligence. Studying the applicability of ant colony algorithm based on more features and exploring the advantages and performance of ant colony algorithm are provided with very important significance. The study takes the outskirts of Fuzhou with complicated land use in Fujian Province as study area. The multi-source database which contains the integration of spectral information (TM1-5, TM7, NDVI, NDBI) and topography characters (DEM, Slope, Aspect) and textural information (Mean, Variance, Homogeneity, Contrast, Dissimilarity, Entropy, Second Moment, Correlation) were built. Classification rules based different characters are discovered from the samples through ant colony algorithm and the classification test is performed based on these rules. At the same time, we compare with traditional maximum likelihood method, C4.5 algorithm and rough sets classifications for checking over the accuracies. The study showed that the accuracy of classification based on the ant colony algorithm is higher than other methods. In addition, the land use and cover changes in Fuzhou for the near term is studied and display the figures by using remote sensing technology based on ant colony algorithm. In addition, the land use and cover changes in Fuzhou for the near term is studied and display the figures by using

  12. Increasing the accuracy of measurements based on the solution of Pauli's quantum equation

    Science.gov (United States)

    Ermishin, Sergey; Korol, Alexandra

    2013-05-01

    There is a measurements principle that ensures the increase of accuracy of measurements based on redundant measurements. Main properties of the solution are: a discrete method with a surge of probability within the parent entity and comparison of the graph of the probability distribution for the diffraction grids with the graph of probability density function. Method based on the analog of Pauli equation solution. The method of electronic reference measurements with quantum computing applied to mathematical data processing allows to greatly increase the credibility and accuracy of measurements at low cost, which is confirmed by simulation.

  13. Accuracy of a class of concurrent algorithms for transient finite element analysis

    Science.gov (United States)

    Ortiz, Michael; Sotelino, Elisa D.; Nour-Omid, Bahram

    1988-01-01

    The accuracy of a new class of concurrent procedures for transient finite element analysis is examined. A phase error analysis is carried out which shows that wave retardation leading to unacceptable loss of accuracy may occur if a Courant condition based on the dimensions of the subdomains is violated. Numerical tests suggest that this Courant condition is conservative for typical structural applications and may lead to a marked increase in accuracy as the number of subdomains is increased. Theoretical speed-up ratios are derived which suggest that the algorithms under consideration can be expected to exhibit a performance superior to that of globally implicit methods when implemented on parallel machines.

  14. Increasing imputation and prediction accuracy for Chinese Holsteins using joint Chinese-Nordic reference population

    DEFF Research Database (Denmark)

    Ma, Peipei; Lund, Mogens Sandø; Ding, X;

    2015-01-01

    genotyped with 54K chip, 510 Nordic Holstein bulls genotyped with HD chip, and 4398 Nordic Holstein bulls genotyped with 54K chip and with deregressed proofs for five milk production traits. Based on these data, the accuracy of imputation from 54K to HD marker data and the accuracy of genomic predictions...... was improved slightly when using the marker data imputed based on the combined HD reference data, compared with using the marker data imputed based on the Chinese HD reference data only. On the other hand, when using the combined reference population including 4398 Nordic Holstein bulls, the accuracy...... of genomic predictions increased 6.5 percentage points together with a reduction of prediction bias. The HD markers did not outperform the 54K markers in genomic prediction based on the present data. The results indicate that for Chinese Holsteins, it is necessary to genotype more individuals with 54K chip...

  15. A new entropy condition for increasing accuracy and convergence rate of TVD scheme

    Energy Technology Data Exchange (ETDEWEB)

    Rashidi, M.M. [Buali-Sina Univ., Mechanical Engineering Dept., Hamadan (Iran, Islamic Republic of)]. E-mail: mm_rashidi@yahoo.com; Esfahanian, V. [Univ. of Tehran, Mechanical Engineering Dept., Tehran (Iran, Islamic Republic of)

    2005-07-01

    In this paper, a TVD method is applied to the numerical solution of the flow over axisymmetric steady hypersonic viscous flow using TLNS equations over blunt cone. In the TVD schemes, the artificial viscosity (AV) is implemented using entropy condition. For hypersonic flow, Yee entropy condition shows relatively a better stability and convergence rate than others. This paper presents a new entropy condition for increasing the accuracy and convergence rate of the TVD scheme which does not have the difficulty associated with Yee entropy condition for viscous flow in the hypersonic regime. The entropy condition increases the AV in the shocks and decreases AV in the smooth region. The numerical solution has been compared with the Beam and Warming shock fitting approach indicating a better numerical accuracy. (author)

  16. An Increase in Estimation Accuracy Position Determination of Inertial Measurement Units

    Directory of Open Access Journals (Sweden)

    Beran Ladislav

    2016-01-01

    Full Text Available This paper deals with an increase in measurement accuracy of the Inertial Measurement Units (IMU. In the Inertial Navigation Systems (INS a fusion of gyroscopes, accelerometers and in some cases magnetometers are typically used. The typical problem of cheap IMU is non-stationary offset and high level of noise. The next problem of IMU is a problem with a bumpy floor. For this case it is necessary to a have high quality chassis to eliminate additional noise. Also, it is possible to eliminate this noise by using some algorithm, but results are still poor. These properties lead to the inaccurate position estimation in the integration process. Even a small offset error leads to a big mistake in position determination and grows quickly with a time. This research is focused on the elimination of these poor properties and increase of accuracy of position estimation using Kalman Filtration.

  17. Increased accuracy of ligand sensing by receptor diffusion on cell surface

    Science.gov (United States)

    Aquino, Gerardo; Endres, Robert G.

    2010-10-01

    The physical limit with which a cell senses external ligand concentration corresponds to the perfect absorber, where all ligand particles are absorbed and overcounting of same ligand particles does not occur. Here, we analyze how the lateral diffusion of receptors on the cell membrane affects the accuracy of sensing ligand concentration. Specifically, we connect our modeling to neurotransmission in neural synapses where the diffusion of glutamate receptors is already known to refresh synaptic connections. We find that receptor diffusion indeed increases the accuracy of sensing for both the glutamate α -Amino-3-hydroxy-5-Methyl-4-isoxazolePropionic Acid (AMPA) and N -Methyl-D-aspartic Acid (NMDA) receptor, although the NMDA receptor is overall much noisier. We propose that the difference in accuracy of sensing of the two receptors can be linked to their different roles in neurotransmission. Specifically, the high accuracy in sensing glutamate is essential for the AMPA receptor to start membrane depolarization, while the NMDA receptor is believed to work in a second stage as a coincidence detector, involved in long-term potentiation and memory.

  18. Range accuracy analysis of streak tube imaging lidar systems

    Science.gov (United States)

    Ye, Guangchao; Fan, Rongwei; Chen, Zhaodong; Yuan, Wei; Chen, Deying; He, Ping

    2016-02-01

    Streak tube imaging lidar (STIL) is an active imaging system that has a high range accuracy and a wide range gate with the use of a pulsed laser transmitter and streak tube receiver to produce 3D range images. This work investigates the range accuracy performance of STIL systems based on a peak detection algorithm, taking into account the effects of blurring of the image. A theoretical model of the time-resolved signal distribution, including the static blurring width in addition to the laser pulse width, is presented, resulting in a modified range accuracy analysis. The model indicates that the static blurring width has a significant effect on the range accuracy, which is validated by both the simulation and experimental results. By using the optimal static blurring width, the range accuracies are enhanced in both indoor and outdoor experiments, with a stand-off distance of 10 m and 1700 m, respectively, and corresponding, best range errors of 0.06 m and 0.25 m were achieved in a daylight environment.

  19. Neutron electric dipole moment and possibilities of increasing accuracy of experiments

    Energy Technology Data Exchange (ETDEWEB)

    Serebrov, A. P., E-mail: serebrov@pnpi.spb.ru; Kolomenskiy, E. A.; Pirozhkov, A. N.; Krasnoshchekova, I. A.; Vasiliev, A. V.; Polyushkin, A. O.; Lasakov, M. S.; Murashkin, A. N.; Solovey, V. A.; Fomin, A. K.; Shoka, I. V.; Zherebtsov, O. M. [National Research Centre “Kurchatov Institute”, Petersburg Nuclear Physics Institute (Russian Federation); Aleksandrov, E. B.; Dmitriev, S. P.; Dovator, N. A. [Russian Academy of Sciences, Ioffe Physical Technical Institute (Russian Federation); Geltenbort, P.; Ivanov, S. N.; Zimmer, O. [Institut Max von Laue–Paul Langevin (France)

    2016-01-15

    The paper reports the results of an experiment on searching for the neutron electric dipole moment (EDM), performed on the ILL reactor (Grenoble, France). The double-chamber magnetic resonance spectrometer (Petersburg Nuclear Physics Institute (PNPI)) with prolonged holding of ultra cold neutrons has been used. Sources of possible systematic errors are analyzed, and their influence on the measurement results is estimated. The ways and prospects of increasing accuracy of the experiment are discussed.

  20. Neutron electric dipole moment and possibilities of increasing accuracy of experiments

    Science.gov (United States)

    Serebrov, A. P.; Kolomenskiy, E. A.; Pirozhkov, A. N.; Krasnoshchekova, I. A.; Vasiliev, A. V.; Polyushkin, A. O.; Lasakov, M. S.; Murashkin, A. N.; Solovey, V. A.; Fomin, A. K.; Shoka, I. V.; Zherebtsov, O. M.; Aleksandrov, E. B.; Dmitriev, S. P.; Dovator, N. A.; Geltenbort, P.; Ivanov, S. N.; Zimmer, O.

    2016-01-01

    The paper reports the results of an experiment on searching for the neutron electric dipole moment (EDM), performed on the ILL reactor (Grenoble, France). The double-chamber magnetic resonance spectrometer (Petersburg Nuclear Physics Institute (PNPI)) with prolonged holding of ultra cold neutrons has been used. Sources of possible systematic errors are analyzed, and their influence on the measurement results is estimated. The ways and prospects of increasing accuracy of the experiment are discussed.

  1. Sensitivity analysis for high accuracy proximity effect correction

    Science.gov (United States)

    Thrun, Xaver; Browning, Clyde; Choi, Kang-Hoon; Figueiro, Thiago; Hohle, Christoph; Saib, Mohamed; Schiavone, Patrick; Bartha, Johann W.

    2015-10-01

    A sensitivity analysis (SA) algorithm was developed and tested to comprehend the influences of different test pattern sets on the calibration of a point spread function (PSF) model with complementary approaches. Variance-based SA is the method of choice. It allows attributing the variance of the output of a model to the sum of variance of each input of the model and their correlated factors.1 The objective of this development is increasing the accuracy of the resolved PSF model in the complementary technique through the optimization of test pattern sets. Inscale® from Aselta Nanographics is used to prepare the various pattern sets and to check the consequences of development. Fraunhofer IPMS-CNT exposed the prepared data and observed those to visualize the link of sensitivities between the PSF parameters and the test pattern. First, the SA can assess the influence of test pattern sets for the determination of PSF parameters, such as which PSF parameter is affected on the employments of certain pattern. Secondly, throughout the evaluation, the SA enhances the precision of PSF through the optimization of test patterns. Finally, the developed algorithm is able to appraise what ranges of proximity effect correction is crucial on which portion of a real application pattern in the electron beam exposure.

  2. Mesoscale modelling methodology based on nudging to increase accuracy in WRA

    Science.gov (United States)

    Mylonas Dirdiris, Markos; Barbouchi, Sami; Hermmann, Hugo

    2016-04-01

    The offshore wind energy has recently become a rapidly growing renewable energy resource worldwide, with several offshore wind projects in development in different planning stages. Despite of this, a better understanding of the atmospheric interaction within the marine atmospheric boundary layer (MABL) is needed in order to contribute to a better energy capture and cost-effectiveness. Light has been thrown in observational nudging as it has recently become an innovative method to increase the accuracy of wind flow modelling. This particular study focuses on the observational nudging capability of Weather Research and Forecasting (WRF) and ways the uncertainty of wind flow modelling in the wind resource assessment (WRA) can be reduced. Finally, an alternative way to calculate the model uncertainty is pinpointed. Approach WRF mesoscale model will be nudged with observations from FINO3 at three different heights. The model simulations with and without applying observational nudging will be verified against FINO1 measurement data at 100m. In order to evaluate the observational nudging capability of WRF two ways to derive the model uncertainty will be described: one global uncertainty and an uncertainty per wind speed bin derived using the recommended practice of the IEA in order to link the model uncertainty to a wind energy production uncertainty. This study assesses the observational data assimilation capability of WRF model within the same vertical gridded atmospheric column. The principal aim is to investigate whether having observations up to one height could improve the simulation at a higher vertical level. The study will use objective analysis implementing a Cress-man scheme interpolation to interpolate the observation in time and in sp ace (keeping the horizontal component constant) to the gridded analysis. Then the WRF model core will incorporate the interpolated variables to the "first guess" to develop a nudged simulation. Consequently, WRF with and without

  3. Accuracy Enhancement of Inertial Sensors Utilizing High Resolution Spectral Analysis

    Directory of Open Access Journals (Sweden)

    Michael Korenberg

    2012-08-01

    Full Text Available In both military and civilian applications, the inertial navigation system (INS and the global positioning system (GPS are two complementary technologies that can be integrated to provide reliable positioning and navigation information for land vehicles. The accuracy enhancement of INS sensors and the integration of INS with GPS are the subjects of widespread research. Wavelet de-noising of INS sensors has had limited success in removing the long-term (low-frequency inertial sensor errors. The primary objective of this research is to develop a novel inertial sensor accuracy enhancement technique that can remove both short-term and long-term error components from inertial sensor measurements prior to INS mechanization and INS/GPS integration. A high resolution spectral analysis technique called the fast orthogonal search (FOS algorithm is used to accurately model the low frequency range of the spectrum, which includes the vehicle motion dynamics and inertial sensor errors. FOS models the spectral components with the most energy first and uses an adaptive threshold to stop adding frequency terms when fitting a term does not reduce the mean squared error more than fitting white noise. The proposed method was developed, tested and validated through road test experiments involving both low-end tactical grade and low cost MEMS-based inertial systems. The results demonstrate that in most cases the position accuracy during GPS outages using FOS de-noised data is superior to the position accuracy using wavelet de-noising.

  4. Accuracy of multi-point boundary crossing time analysis

    Directory of Open Access Journals (Sweden)

    J. Vogt

    2011-12-01

    Full Text Available Recent multi-spacecraft studies of solar wind discontinuity crossings using the timing (boundary plane triangulation method gave boundary parameter estimates that are significantly different from those of the well-established single-spacecraft minimum variance analysis (MVA technique. A large survey of directional discontinuities in Cluster data turned out to be particularly inconsistent in the sense that multi-point timing analyses did not identify any rotational discontinuities (RDs whereas the MVA results of the individual spacecraft suggested that RDs form the majority of events. To make multi-spacecraft studies of discontinuity crossings more conclusive, the present report addresses the accuracy of the timing approach to boundary parameter estimation. Our error analysis is based on the reciprocal vector formalism and takes into account uncertainties both in crossing times and in the spacecraft positions. A rigorous error estimation scheme is presented for the general case of correlated crossing time errors and arbitrary spacecraft configurations. Crossing time error covariances are determined through cross correlation analyses of the residuals. The principal influence of the spacecraft array geometry on the accuracy of the timing method is illustrated using error formulas for the simplified case of mutually uncorrelated and identical errors at different spacecraft. The full error analysis procedure is demonstrated for a solar wind discontinuity as observed by the Cluster FGM instrument.

  5. Stability and Accuracy Analysis for Taylor Series Numerical Method

    Institute of Scientific and Technical Information of China (English)

    赵丽滨; 姚振汉; 王寿梅

    2004-01-01

    The Taylor series numerical method (TSNM) is a time integration method for solving problems in structural dynamics. In this paper, a detailed analysis of the stability behavior and accuracy characteristics of this method is given. It is proven by a spectral decomposition method that TSNM is conditionally stable and belongs to the category of explicit time integration methods. By a similar analysis, the characteristic indicators of time integration methods, the percentage period elongation and the amplitude decay of TSNM, are derived in a closed form. The analysis plays an important role in implementing a procedure for automatic searching and finding convergence radii of TSNM. Finally, a linear single degree of freedom undamped system is analyzed to test the properties of the method.

  6. Aspects of precision and accuracy in neutron activation analysis

    International Nuclear Information System (INIS)

    Analytical results without systematic errors and with accurately known random errors are normally distributed around their true values. Such results may be produced by means of neutron activation analysis both with and without radiochemical separation. When all sources of random variation are known a priori, their effect may be combined with the Poisson statistics characteristic of the counting process, and the standard deviation of a single analytical result may be estimated. The various steps of a complete neutron activation analytical procedure are therefore studied in detail with respect to determining their contribution to the overall variability of the final result. Verification of the estimated standard deviation is carried out by demonstrating the absence of significant unknown random errors through analysing, in replicate, samples covering the range of concentrations and matrices anticipated in actual use. Agreement between the estimated and the observed variability of replicate results is then tested by a simple statistic T based on the chi-square distribution. It is found that results from neutron activation analysis on biological samples can be brought into statistical control. In routine application of methods in statistical control the same statistical test may be used for quality control when some of the actual samples are analysed in duplicate. This analysis of precision serves to detect unknown or unexpected sources of variation of the analytical results, and both random and systematic errors have been discovered in practical trace element investigations in different areas of research. Particularly, at the ultratrace level of concentration where there are few or no standard reference materials for ascertaining the accuracy of results, the proposed quality control based on the analysis of precision combined with neutron activation analysis with radiochemical separation, with an a priori precision independent of the level of concentration, becomes a

  7. Gender Analysis On Islamic Texts: A Study On Its Accuracy

    Directory of Open Access Journals (Sweden)

    Muchammad Ichsan

    2014-06-01

    Full Text Available Gender equality movement is spreading all over the world, including in Indonesia where Muslim gender activists have made hard efforts to ensure gender fairness and equality among people. One of their efforts is emphasizing the urgency of reinterpreting Islamic texts. They insist on the reinterpretation of Islamic texts based on gender perspective and analysis due to the existence of many Islamic texts that trespass the principles of gender equality and fairness they have been fighting for. This paper aims at assuring and examining the accuracy of using gender perspective as a tool for analyzing the Islamic text. It is found that using gender perspective and analysis for reinterpreting Islamic texts is not in line with the Islamic principles and will only produce laws and points of views which deviate from Islamic teachings. To reach the goals of this study, a descriptive-analytical approach is employed.

  8. The combined use of conventional MRI and MR spectroscopic imaging increases the diagnostic accuracy in amyotrophic lateral sclerosis

    Energy Technology Data Exchange (ETDEWEB)

    Cervo, Amedeo [Department of Advanced Biomedical Sciences, University “Federico II”, Naples (Italy); Cocozza, Sirio, E-mail: siriococozza@hotmail.it [Department of Advanced Biomedical Sciences, University “Federico II”, Naples (Italy); Saccà, Francesco [Department of Neurosciences, Reproductive Sciences and Odontostomatology, University “Federico II”, Naples (Italy); Giorgio, Sara M.d.A. [Department of Advanced Biomedical Sciences, University “Federico II”, Naples (Italy); Morra, Vincenzo Brescia [Department of Neurosciences, Reproductive Sciences and Odontostomatology, University “Federico II”, Naples (Italy); Tedeschi, Enrico [Department of Advanced Biomedical Sciences, University “Federico II”, Naples (Italy); Marsili, Angela; Vacca, Giovanni [Department of Neurosciences, Reproductive Sciences and Odontostomatology, University “Federico II”, Naples (Italy); Palma, Vincenzo [U.O.C. Neurofisiopatologia, PO S. Gennaro ASL Napoli 1, Naples (Italy); Brunetti, Arturo [Department of Advanced Biomedical Sciences, University “Federico II”, Naples (Italy); Quarantelli, Mario [Biostructure and Bioimaging Institute, National Research Council, Naples (Italy)

    2015-01-15

    Highlights: • We assessed in ALS the diagnostic accuracy of MRI signal and MRS data used alone and in combination. • We found that T2-hypointensity and NAA decrease in motor cortex are two independent phenomena. • These two variables taken alone do not provide acceptable diagnostic accuracy in ALS. • The same variables, when used in combination, improve the diagnostic accuracy of MRI in ALS. - Abstract: Purpose: We aimed to assess, in amyotrophic lateral sclerosis (ALS), the diagnostic accuracy of the combined use of conventional MRI signal changes (namely, hypointensity of the precentral cortex and hyperintensity of the corticospinal tracts on T2-weighted images), and N-Acetyl-Aspartate (NAA) reduction in the motor cortex at Magnetic Resonance Spectroscopy (MRS), which are affected by limited diagnostic accuracy when used separately. Methods: T2-hypointensity and NAA/(Choline + Creatine) ratio of the precentral gyrus and T2-hyperintensity of the corticospinal tracts were measured in 84 ALS patients and 28 healthy controls, using a Region-of-Interest approach. Sensitivity and specificity values were calculated using Fisher stepwise discriminant analysis, and cross-validated using the leave-one-out method. Results: Precentral gyrus T2 signal intensity (p < 10{sup −4}) and NAA peak (p < 10{sup −6}) were significantly reduced in patients, and their values did not correlate significantly to each other both in patients and controls, while no significant differences were obtained in terms of T2-hyperintensity of the corticospinal tract. Sensitivity and specificity of the two discriminant variables, taken alone, were 71.4% and 75.0%, for NAA peak, and 63.1% and 71.4% for T2-hypointensity, respectively. When using these two variables in combination, a significant increase in sensitivity (78.6%) and specificity (82.1%) was achieved. Conclusions: Precentral gyrus T2-hypointensity and NAA peak are not significantly correlated in ALS patients, suggesting that they

  9. The combined use of conventional MRI and MR spectroscopic imaging increases the diagnostic accuracy in amyotrophic lateral sclerosis

    International Nuclear Information System (INIS)

    Highlights: • We assessed in ALS the diagnostic accuracy of MRI signal and MRS data used alone and in combination. • We found that T2-hypointensity and NAA decrease in motor cortex are two independent phenomena. • These two variables taken alone do not provide acceptable diagnostic accuracy in ALS. • The same variables, when used in combination, improve the diagnostic accuracy of MRI in ALS. - Abstract: Purpose: We aimed to assess, in amyotrophic lateral sclerosis (ALS), the diagnostic accuracy of the combined use of conventional MRI signal changes (namely, hypointensity of the precentral cortex and hyperintensity of the corticospinal tracts on T2-weighted images), and N-Acetyl-Aspartate (NAA) reduction in the motor cortex at Magnetic Resonance Spectroscopy (MRS), which are affected by limited diagnostic accuracy when used separately. Methods: T2-hypointensity and NAA/(Choline + Creatine) ratio of the precentral gyrus and T2-hyperintensity of the corticospinal tracts were measured in 84 ALS patients and 28 healthy controls, using a Region-of-Interest approach. Sensitivity and specificity values were calculated using Fisher stepwise discriminant analysis, and cross-validated using the leave-one-out method. Results: Precentral gyrus T2 signal intensity (p < 10−4) and NAA peak (p < 10−6) were significantly reduced in patients, and their values did not correlate significantly to each other both in patients and controls, while no significant differences were obtained in terms of T2-hyperintensity of the corticospinal tract. Sensitivity and specificity of the two discriminant variables, taken alone, were 71.4% and 75.0%, for NAA peak, and 63.1% and 71.4% for T2-hypointensity, respectively. When using these two variables in combination, a significant increase in sensitivity (78.6%) and specificity (82.1%) was achieved. Conclusions: Precentral gyrus T2-hypointensity and NAA peak are not significantly correlated in ALS patients, suggesting that they reflect

  10. Increasing cutaneous afferent feedback improves proprioceptive accuracy at the knee in patients with sensory ataxia.

    Science.gov (United States)

    Macefield, Vaughan G; Norcliffe-Kaufmann, Lucy; Goulding, Niamh; Palma, Jose-Alberto; Fuente Mora, Cristina; Kaufmann, Horacio

    2016-02-01

    Hereditary sensory and autonomic neuropathy type III (HSAN III) features disturbed proprioception and a marked ataxic gait. We recently showed that joint angle matching error at the knee is positively correlated with the degree of ataxia. Using intraneural microelectrodes, we also documented that these patients lack functional muscle spindle afferents but have preserved large-diameter cutaneous afferents, suggesting that patients with better proprioception may be relying more on proprioceptive cues provided by tactile afferents. We tested the hypothesis that enhancing cutaneous sensory feedback by stretching the skin at the knee joint using unidirectional elasticity tape could improve proprioceptive accuracy in patients with a congenital absence of functional muscle spindles. Passive joint angle matching at the knee was used to assess proprioceptive accuracy in 25 patients with HSAN III and 9 age-matched control subjects, with and without taping. Angles of the reference and indicator knees were recorded with digital inclinometers and the absolute error, gradient, and correlation coefficient between the two sides calculated. Patients with HSAN III performed poorly on the joint angle matching test [mean matching error 8.0 ± 0.8° (±SE); controls 3.0 ± 0.3°]. Following application of tape bilaterally to the knee in an X-shaped pattern, proprioceptive performance improved significantly in the patients (mean error 5.4 ± 0.7°) but not in the controls (3.0 ± 0.2°). Across patients, but not controls, significant increases in gradient and correlation coefficient were also apparent following taping. We conclude that taping improves proprioception at the knee in HSAN III, presumably via enhanced sensory feedback from the skin.

  11. Convective Weather Forecast Accuracy Analysis at Center and Sector Levels

    Science.gov (United States)

    Wang, Yao; Sridhar, Banavar

    2010-01-01

    This paper presents a detailed convective forecast accuracy analysis at center and sector levels. The study is aimed to provide more meaningful forecast verification measures to aviation community, as well as to obtain useful information leading to the improvements in the weather translation capacity models. In general, the vast majority of forecast verification efforts over past decades have been on the calculation of traditional standard verification measure scores over forecast and observation data analyses onto grids. These verification measures based on the binary classification have been applied in quality assurance of weather forecast products at the national level for many years. Our research focuses on the forecast at the center and sector levels. We calculate the standard forecast verification measure scores for en-route air traffic centers and sectors first, followed by conducting the forecast validation analysis and related verification measures for weather intensities and locations at centers and sectors levels. An approach to improve the prediction of sector weather coverage by multiple sector forecasts is then developed. The weather severe intensity assessment was carried out by using the correlations between forecast and actual weather observation airspace coverage. The weather forecast accuracy on horizontal location was assessed by examining the forecast errors. The improvement in prediction of weather coverage was determined by the correlation between actual sector weather coverage and prediction. observed and forecasted Convective Weather Avoidance Model (CWAM) data collected from June to September in 2007. CWAM zero-minute forecast data with aircraft avoidance probability of 60% and 80% are used as the actual weather observation. All forecast measurements are based on 30-minute, 60- minute, 90-minute, and 120-minute forecasts with the same avoidance probabilities. The forecast accuracy analysis for times under one-hour showed that the errors in

  12. Accuracy Analysis for SST Gravity Field Model in China

    Institute of Scientific and Technical Information of China (English)

    LUO Jia; LUO Zhicai; ZOU Xiancai; WANG Haihong

    2006-01-01

    Taking China as the region for test, the potential of the new satellite gravity technique, satellite-to-satellite tracking for improving the accuracy of regional gravity field model is studied. With WDM94 as reference, the gravity anomaly residuals of three models, the latest two GRACE global gravity field model (EIGEN_GRACE02S, GGM02S) and EGM96, are computed and compared. The causes for the differences among the residuals of the three models are discussed. The comparison between the residuals shows that in the selected region, EIGEN_GRACE02S or GGM02S is better than EGM96 in lower degree part (less than 110 degree). Additionally, through the analysis of the model gravity anomaly residuals, it is found that some systematic errors with periodical properties exist in the higher degree part of EIGEN and GGM models, the results can also be taken as references in the validation of the SST gravity data.

  13. ANALYSIS OF THE ACCURACY OF FIBRE-OPTIC STRAIN GAUGES

    Directory of Open Access Journals (Sweden)

    Dita Jiroutová

    2013-12-01

    Full Text Available In recent years, the field of structure monitoring has been making increasing use of systems based on fiber-optic technologies. Fiber-optic technology offers many advantages, including higher quality measurements, greater reliability, easier installation and maintenance, insensitivity to the environment (mainly to the electromagnetic field, corrosion resistance, safety in explosive and flammable environments, the possibility of long-term monitoring and lower cost per lifetime. We have used SOFO fibre-optic strain gauges to perform measurements to check the overall relative deformation of a real reinforced concrete structure. Long-term monitoring of the structure revealed that the measurement readings obtained from these fibre-optic strain gauges differed from each other. Greater attention was therefore paid to the calibration of the fibre-optic strain gauges, and to determining their measurement accuracy. The experimental results show that it is necessary to calibrate SOFO strain gauges before they are used, and to determine their calibration constant.

  14. Accuracy determination of camera system used for sport motion analysis

    Directory of Open Access Journals (Sweden)

    Bergün Meriç

    2008-10-01

    Full Text Available The aim of this study is to determine accuracy of camera system often used for motion analysis. In order to accomplish this, an industrial robot was moved with known three different trajectories and these motions were captured using three 100Hz cameras located in 3 different angles. Video data were digitized and analyzed using Simi Motion Analysis Program. With this program, angular kinematics were computed from the video data and compared with the data obtained from robot. For considering analysis of the data, average error for angle computed from average values of absolute error and root values of average of squared error is is 0.92° and 1.33°, respectively. Similarly, average error for angular velocity computed from average values of absolute error and root values of average of squared error is is 0.77° and 0.96°, respectively. These errors may result in the technique of image processing, shot speed of camera system and the limited hand sensivity of users. As motions in sports were analyzed with the camera systems, these errors must be taken in account in kinematic computation.

  15. Accuracy determination of camera system used for sport motion analysis

    Directory of Open Access Journals (Sweden)

    Bergün Meriç

    2008-10-01

    Full Text Available The aim of this study is to determine accuracy of camera system often used for motion analysis.       In order to accomplish this, an industrial robot was moved with known three different trajectories  and these motions were captured using three 100Hz cameras located in 3 different angles. Video data were digitized and analyzed using Simi Motion Analysis Program. With this program, angular kinematics were computed from the video data and compared with the data obtained from robot.       For considering analysis of the data, average error for angle computed from average values of absolute error and root values of average of squared error is is  0.92° and 1.33°, respectively. Similarly, average error for angular velocity computed from average values of absolute error and root values of average of squared error is is  0.77° and 0.96°, respectively.      These errors may result in the technique of image processing, shot speed of camera system and  the limited hand sensivity of users. As motions in sports were analyzed with the camera systems, these errors must be taken in account in kinematic computation.

  16. Consideration of generated beam angles increases the accuracy of ultrasonic displacement measurements

    Directory of Open Access Journals (Sweden)

    Sumi C

    2012-03-01

    Full Text Available Chikayoshi Sumi, Yuuki Takanashi, Kento IchimaruDepartment of Information and Communication Sciences, Faculty of Science and Technology, Sophia University, Tokyo, JapanAbstract: The development of practical ultrasonic (US tissue displacement measurement methods increases the number of available and useful applications of displacement/strain measurements that can be made (eg, various blood flow measurements and measurements of tissue motion in organs such as the heart, liver, and so forth. Previously developed lateral modulation (LM methods with a multidimensional autocorrelation method (MAM or multidimensional Doppler method (MDM and a steering angle method (ASTA with lateral Doppler method produced accurate displacement vector and lateral displacement measurements, respectively. Such measurements cannot be obtained using only a conventional Doppler technique. Another new method has also been reported, using multiple crossed beams (MCBs to obtain high-accuracy displacement vector measurements; that is, a displacement vector is synthesized using accurately measured axial displacements with previously developed multidimensional displacement measurement methods, including the one-dimensional autocorrelation method (1D AM with a multidimensional moving average (MA, together with conventional rotation processing of global echo data or a coordinate system (ie, a global echo rotation referred to as r method by the negative value of the steering angles used in beamforming. However, in real-world applications, directivities of transmission and reception apertures, scattering, reflection, and attenuation affect the direction and properties of US beams used for conventional axial displacement measurements employing beamforming methods such as a conventional nonsteered, steered, or secta beam, and they also affect ASTA and MCB methods. In this report, to improve accuracy in the measurements of an arbitrary directional displacement and a displacement vector

  17. Virtual Teaching Simulation for Robot Assembly Accuracy Analysis

    Institute of Scientific and Technical Information of China (English)

    张征; 周宏甫; 刘斌

    2004-01-01

    In this paper, by teaching a 3D robot unit model and playing back to simulate the assembly process in a virtual assembly environment, errors in robot assembly are analyzed. The paper also presents a visualization method for analyzing accuracy of the robot assembly, and studies the influence of the spatial pose of a robot on the success rate of an axis-hole assembly, and accuracy of the robot teaching program in particular. Through integration of various errors and on the basis of assembly accuracy, tolerance of error sources can be reasonably distributed to meet the assembly accuracy requirement, therefore the planning of robot assembly unit can be improved.

  18. Accuracy and performance analysis of a nuclear belt weigher

    International Nuclear Information System (INIS)

    Nuclear belt weighers have a broad range of applications in the solid particle industry. This work analyzes the accuracy and sensitivity of nuclear weighers for a wide range of operational conditions and design parameters. The problem of the effect of material profile and bulk density variations on the scale performance is quantitatively addressed. A new methodology is developed to calculate the minimum detectable load accounting for both accuracy and sensitivity. Accuracies of less than 1% can be achieved in some ideal situations by proper design of the source length and geometrical configuration. (orig.)

  19. Increasing value in diagnostic research: Publication and reporting of test accuracy studies

    NARCIS (Netherlands)

    D.A. Korevaar

    2016-01-01

    Diagnostic tests form an essential part of daily clinical practice. Unfortunately, most tests are not perfectly accurate; they usually produce a proportion of false positive and false negative results. Diagnostic accuracy studies evaluate a test’s ability to find out whether or not individuals have

  20. Effective Analysis of Chinese Word-Segmentation Accuracy

    Institute of Scientific and Technical Information of China (English)

    MA Weiyin

    2007-01-01

    Automatic word-segmentation is widely used in the ambiguity cancellation when processing large-scale real text,but during the process of unknown word detection in Chinese word segmentation,many detected word candidates are invalid.These false unknown word candidates deteriorate the overall segmentation accuracy,as it will affect the segmentation accuracy of known words.In this paper,we propose several methods for reducing the difficulties and improving the accuracy of the word-segmentation of written Chinese,such as full segmentation of a sentence,processing the duplicative word,idioms and statistical identification for unknown words.A simulation shows the feasibility of our proposed methods in improving the accuracy of word-segmentation of Chinese.

  1. Accuracy of gas analysis in lung function laboratories.

    OpenAIRE

    Chinn, D.J.; Naruse, Y; Cotes, J E

    1986-01-01

    Fifty lung function laboratories in England and Wales analysed test gas mixtures of carbon monoxide and helium. Most of them also analysed mixtures of oxygen and carbon dioxide in nitrogen. The percentage accuracy of the results was within 1% of the expected value in only 14% of determinations of carbon monoxide concentration, 28% for carbon dioxide, 37% for helium, and 48% for oxygen. The accuracy of ratios of two concentrations of helium and carbon monoxide was better than that of the indiv...

  2. Using student-managed interventions to increase homework completion and accuracy.

    Science.gov (United States)

    Olympia, D E; Sheridan, S M; Jenson, W R; Andrews, D

    1994-01-01

    We examined the effectiveness of self-managed individual and group contingency procedures in improving the completion and accuracy rates of daily mathematics homework assignments. A group of sixth-grade students having homework difficulties in mathematics were selected for the study. There was substantial improvement in the amount of homework completed over baseline for a majority of the students, whereas the results for accuracy were mixed. Students who participated in the self-management training made significant gains on standardized measures of academic achievement and curriculum-based measures of classroom performance. Parents also reported significantly fewer problems associated with homework completion following the intervention. Students who were allowed to select their own performance goals made superior improvements in the number of homework assignments returned compared to students who were given a specified goal by the classroom teacher. Parents, subjects, and the classroom teacher responded positively on consumer satisfaction measures following termination of the study. PMID:16795827

  3. Dual specimens increase the diagnostic accuracy and reduce the reaction duration of rapid urease test

    Institute of Scientific and Technical Information of China (English)

    Wen-Hung; Hsu; Sophie; SW; Wang; Chiao-Yun; Chen; Ching-Wen; Chang; Jaw-Yuan; Wang; Yuan-Chieh; Yang; Deng-Chyang; Wu; Ming-Tsang; Wu

    2010-01-01

    AIM:To evaluate the influence of multiple samplings during esophagogastr oduodenoscopy(EGD) on the accuracy of the rapid urease test,and the validity of newly developed rapid urease tests,HelicotecUT plus test and HelicotecUT test,CLO test and ProntoDry test.METHODS:A total of 355 patients undergoing EGD for dyspepsia were included.Their Helicobacter pylori(H.pylori) treatment status was either nave or eradicated.Six biopsy specimens from antrum and gastric body,respectively,were obtained during EGD.Single...

  4. Increasing the precision and accuracy of top-loading balances:  application of experimental design.

    Science.gov (United States)

    Bzik, T J; Henderson, P B; Hobbs, J P

    1998-01-01

    The traditional method of estimating the weight of multiple objects is to obtain the weight of each object individually. We demonstrate that the precision and accuracy of these estimates can be improved by using a weighing scheme in which multiple objects are simultaneously on the balance. The resulting system of linear equations is solved to yield the weight estimates for the objects. Precision and accuracy improvements can be made by using a weighing scheme without requiring any more weighings than the number of objects when a total of at least six objects are to be weighed. It is also necessary that multiple objects can be weighed with about the same precision as that obtained with a single object, and the scale bias remains relatively constant over the set of weighings. Simulated and empirical examples are given for a system of eight objects in which up to five objects can be weighed simultaneously. A modified Plackett-Burman weighing scheme yields a 25% improvement in precision over the traditional method and implicitly removes the scale bias from seven of the eight objects. Applications of this novel use of experimental design techniques are shown to have potential commercial importance for quality control methods that rely on the mass change rate of an object. PMID:21644600

  5. Improving the Accuracy of Software-Based Energy Analysis for Residential Buildings (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Polly, B.

    2011-09-01

    This presentation describes the basic components of software-based energy analysis for residential buildings, explores the concepts of 'error' and 'accuracy' when analysis predictions are compared to measured data, and explains how NREL is working to continuously improve the accuracy of energy analysis methods.

  6. Increasing accuracy of dispersal kernels in grid-based population models

    Science.gov (United States)

    Slone, D.H.

    2011-01-01

    Dispersal kernels in grid-based population models specify the proportion, distance and direction of movements within the model landscape. Spatial errors in dispersal kernels can have large compounding effects on model accuracy. Circular Gaussian and Laplacian dispersal kernels at a range of spatial resolutions were investigated, and methods for minimizing errors caused by the discretizing process were explored. Kernels of progressively smaller sizes relative to the landscape grid size were calculated using cell-integration and cell-center methods. These kernels were convolved repeatedly, and the final distribution was compared with a reference analytical solution. For large Gaussian kernels (σ > 10 cells), the total kernel error was population took to reach a defined goal, the discrete model results were comparable to the analytical reference. With Gaussian kernels that had σ ≤ 0.12 using the cell integration method, or σ ≤ 0.22 using the cell center method, the kernel error was greater than 10%, which resulted in invasion times that were orders of magnitude different than theoretical results. A goal-seeking routine was developed to adjust the kernels to minimize overall error. With this, corrections for small kernels were found that decreased overall kernel error to <10-11 and invasion time error to <5%.

  7. Reflux esophagitis revisited: Prospective analysis of radiologic accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Ott, D.J.; Gelfand, D.W.; Wu, W.C.

    1981-01-15

    A prospective radiologic-endoscopic study of the esophagogastric region in 266 patients, including 206 normals and 60 with esophagitis, is reported. The endoscopic classification grading severity of esophagitis was grade 1-normal; grades 2. 3. and 4-mild, moderate, and severe esophagitis, respectively. Radiology detected 22% of patient with mild esophagitis, 83% with moderate esophagitis, and 95% with severe esophagitis. Although hiatal hernia was present in 40% of normals and 89% with esophagitis, absence of radiographic hiatal hernia excluded esophagitis with 95% accuracy. The implications of this study regarding the role of radiology in evaluating patient with suspected reflux esophagitis are discussed.

  8. Analysis of Robot Accuracy Assessed via its Joint Clearance by Virtual Prototyping Method

    Institute of Scientific and Technical Information of China (English)

    GUO Ling; WANG Li-hong; ZHANG Yu-ru

    2004-01-01

    This paper discusses how joint clearance influences robot end effector positioning accuracy and a robot accuracy analysis approach based on a virtual prototype is proposed. First, a 5-DOF( Degree of freedom) rneurosurgery robot was introduced. Then we built its virtual prototype, made movement planning and measured the manipulator tip accuracy, through which this robot accuracy portrait was obtained. Finally,in order to validate the robot accuracy analysis approach which is based on a virtual prototype, the result was compared with that from a model built by robot forward kinematics and robot differential kinematics.The robot accuracy analysis approach presented in this paper gives a new way to enhance robot design quality, and help to optimize the control and programming of the robot.

  9. Capillary telangiectasias of the pons. Does diffusion-weighted MR increase diagnostic accuracy?

    Energy Technology Data Exchange (ETDEWEB)

    Finkenzeller, Thomas, E-mail: thomas.finkenzeller@kliniken-nordoberpfalz.a [Institute of Diagnostic Radiology, University of Regensburg (Germany); Institute of Radiology, Landes-Nervenklinik Wagner-Jauregg, Linz (Austria); Fellner, Franz A. [Institute of Radiology, AKH Linz, Linz (Austria); Trenkler, Johannes [Institute of Radiology, Landes-Nervenklinik Wagner-Jauregg, Linz (Austria); Schreyer, Andreas [Institute of Diagnostic Radiology, University of Regensburg (Germany); Fellner, Claudia [Institute of Diagnostic Radiology, University of Regensburg (Germany); Institute of Radiology, Landes-Nervenklinik Wagner-Jauregg, Linz (Austria)

    2010-06-15

    Background and Purpose: Capillary telangiectasias are benign lesions of the brainstem which are sometimes difficult to distinguish from other lesions in standard MRI. The purpose of this study was to evaluate if diffusion-weighted imaging (DWI) could help to improve diagnostic accuracy. Methods: 148 MR examinations of patients with pontine lesions were evaluated retrospectively and revealed capillary telangiectasia (n = 18), presumed microvascular disease (n = 20), encephalitis disseminata (n = 21), pontine myelinolysis (n = 16), tumor (n = 20), acute infarction (n = 20), subacute infarction (n = 13) and chronic infarction (n = 20). All patients were examined using identical measurement parameters for DWI, Fluid attenuated inversion recovery, T2-weighted turbo spin-echo, and T1-weighted spin-echo before and after application of contrast agent in transverse orientation. Results: All capillary telangiectasias showed low signal intensity in DWI and significant contrast enhancement after application of gadolinium. Hypointense signal on DWI was very rare for the remaining lesions: only 1 pontine myelinolysis, 1 tumor, 4 subacute infarctions, and 19 chronic infarctions also revealed low signal intensity on DWI. The combination of high signal intensity on T1-weighted post-contrast images and low signal intensity on DWI was found for all capillary telangiectasias, but only for 1/20 tumor and for 4/13 subacute infarctions. These lesions could be differentiated by their clinical course and/or MRI follow-up examinations. The results of the visual assessment were confirmed by quantitative evaluation. Conclusion: DWI seems to be a useful adjunct for the diagnosis of capillary telangiectasias which will facilitate the differential diagnosis concerning tumorous, inflammatory and ischemic lesions.

  10. Does subdivision of the "atypical" urine cytology increase predictive accuracy for urothelial carcinoma?

    Science.gov (United States)

    Bostwick, David G; Hossain, Deloar

    2014-12-01

    Urine cytology is routinely used for early diagnosis and monitoring of patients with hematuria or a history of urothelial carcinoma, but its clinical utility is greatly diminished by a high frequency of "atypical" specimens, reportedly around 20% in the literature. We compared our results with double-stained urine cytology specimens (papanicolaou and acid hematoxylin stains) with published results with only a single or double papanicolaou stain. The acid hematoxylin stain enhanced nuclear chromatin staining, eliminated significant background debris, and improved visibility of diagnostic cells in the presence of obscuring blood. Medical records of all urine cytologies received between 2005 and 2012 in our laboratories were reviewed. The study group consisted of all cases with bladder biopsy follow-up within one year of cytology. Of 43,131 urine cytologies diagnosed in our laboratories, biopsy follow-up results were available within one year in 10,473 cases, including 852 for symptoms and 1,461 for follow-up of bladder cancer. An additional 6,427 cases had cystoscopy results in which no biopsy was obtained. Cases were classified as negative (81.6%), atypical, favor reactive (2.9%), atypical, favor neoplastic (7.3%), suspicious (5.7%), and malignant (2.5%), with subsequent frequencies for urothelial cancer on biopsy of 13.3%, 31.1%, 37.6%, 53.6%, and 74.3%, respectively. No significant difference was found if atypical was subdivided into two categories: favor reactive and favor neoplastic. Subdivision of the atypical category did not improve diagnostic accuracy. Addition of the acid hematoxylin stain decreased the incidence of atypical urine cytologies from about 20% to 10.2%. PMID:24838797

  11. The Use of Scale-Dependent Precision to Increase Forecast Accuracy in Earth System Modelling

    Science.gov (United States)

    Thornes, Tobias; Duben, Peter; Palmer, Tim

    2016-04-01

    At the current pace of development, it may be decades before the 'exa-scale' computers needed to resolve individual convective clouds in weather and climate models become available to forecasters, and such machines will incur very high power demands. But the resolution could be improved today by switching to more efficient, 'inexact' hardware with which variables can be represented in 'reduced precision'. Currently, all numbers in our models are represented as double-precision floating points - each requiring 64 bits of memory - to minimise rounding errors, regardless of spatial scale. Yet observational and modelling constraints mean that values of atmospheric variables are inevitably known less precisely on smaller scales, suggesting that this may be a waste of computer resources. More accurate forecasts might therefore be obtained by taking a scale-selective approach whereby the precision of variables is gradually decreased at smaller spatial scales to optimise the overall efficiency of the model. To study the effect of reducing precision to different levels on multiple spatial scales, we here introduce a new model atmosphere developed by extending the Lorenz '96 idealised system to encompass three tiers of variables - which represent large-, medium- and small-scale features - for the first time. In this chaotic but computationally tractable system, the 'true' state can be defined by explicitly resolving all three tiers. The abilities of low resolution (single-tier) double-precision models and similar-cost high resolution (two-tier) models in mixed-precision to produce accurate forecasts of this 'truth' are compared. The high resolution models outperform the low resolution ones even when small-scale variables are resolved in half-precision (16 bits). This suggests that using scale-dependent levels of precision in more complicated real-world Earth System models could allow forecasts to be made at higher resolution and with improved accuracy. If adopted, this new

  12. Analysis of cost and accuracy of alternative strategies for Enterobacteriaceae identification.

    Science.gov (United States)

    Robertson, E A; Macks, G C; MacLowry, J D

    1976-04-01

    Analysis of the cost of time and material required for the diagnosis of Enterobacteriacea isolates indicated that a conventional 17-tube (20-test) setup costs $7.98 per isolated identified. Using the API 20E, a similar identification cost $3.02. A conventional 7-tube (10-test) setup cost $3.60, whereas the comparable cost by 30% while increasing the number of isolate identified correctly by 3%. Other strategres using the API 20E or a deoxyribounclease test were also evaluated for cost and accuracy. PMID:770498

  13. Fine orbit tuning to increase the accuracy of the gravity-field modelling

    Science.gov (United States)

    Bezdek, A.; Klokocnik, J.; Kostelecky, J.; Floberghagen, R.; Sebera, J.

    2010-12-01

    Fine orbit tuning will be presented as a tool to enhance the accuracy of the gravity-field parameters based on the data from satellite missions around the Earth or other planetary bodies. A slight variation in the satellite altitude of a few hundred metres or kilometres may dramatically change the pattern and density of the groundtracks, thus leading to a significant difference in the quality of the derived gravity-field parameters. This aspect is important not only to missions dedicated to the gravity-field mapping, but it can be applied to any planetary mission, whose orbital data may yield useful information on the particular gravity field. The geometry of satellite groundtracks is closely connected with the term orbital resonance or repeat orbit, which was intensively studied by the satellite geodesy community since the 1970s. In a systematic way, fine orbit tuning was first applied to altimetry missions for oceanographic purposes in the early 1990s, when it became clear that small changes in the satellite altitude might substantially influence the utility of the data from the onboard instruments. The monthly geopotential solutions from the GRACE mission (in orbit since 2002) displayed apparently worse precision in August-September 2004, which was later found to be caused by a sparser groundtrack pattern due to the passage of the GRACE satellites through the 61/4 orbit resonance. The lessons learned from GRACE were applied by ESA to its gravity field mission GOCE (in orbit since 2009). Here, the situation is different, as the GOCE onboard thrusters are capable of maintaining the satellite at a constant altitude. In order to fully use the measurement potential of the first space gradiometer ever flown, in the GOCE mission planning the influence of orbit geometry was taken into account, and a minimum 2-month repeat period for the orbit was specified. We analysed several orbital configurations of GOCE, as possible candidates for the gravity mapping phases. We

  14. Measurement of characteristics and phase modulation accuracy increase of LC SLM 'HoloEye PLUTO VIS'

    International Nuclear Information System (INIS)

    Phase liquid crystal spatial light modulators (LC SLM) are actively integrated in various optical systems for dynamic diffractive optical elements imaging. To achieve the best performance, high stability and linearity of phase modulation is required. This article presents results of measurement of characteristics and phase modulation accuracy increase of state of the art LC SLM with HD resolution 'HoloEye PLUTO VIS'.

  15. Evaluation of precision and accuracy of selenium measurements in biological materials using neutron activation analysis

    International Nuclear Information System (INIS)

    In recent years, the accurate determination of selenium in biological materials has become increasingly important in view of the essential nature of this element for human nutrition and its possible role as a protective agent against cancer. Unfortunately, the accurate determination of selenium in biological materials is often difficult for most analytical techniques for a variety of reasons, including interferences, complicated selenium chemistry due to the presence of this element in multiple oxidation states and in a variety of different organic species, stability and resistance to destruction of some of these organo-selenium species during acid dissolution, volatility of some selenium compounds, and potential for contamination. Neutron activation analysis (NAA) can be one of the best analytical techniques for selenium determinations in biological materials for a number of reasons. Currently, precision at the 1% level (1s) and overall accuracy at the 1 to 2% level (95% confidence interval) can be attained at the U.S. National Bureau of Standards (NBS) for selenium determinations in biological materials when counting statistics are not limiting (using the 75Se isotope). An example of this level of precision and accuracy is summarized. Achieving this level of accuracy, however, requires strict attention to all sources of systematic error. Precise and accurate results can also be obtained after radiochemical separations

  16. Optical System Error Analysis and Calibration Method of High-Accuracy Star Trackers

    OpenAIRE

    Zheng You; Fei Xing; Ting Sun

    2013-01-01

    The star tracker is a high-accuracy attitude measurement device widely used in spacecraft. Its performance depends largely on the precision of the optical system parameters. Therefore, the analysis of the optical system parameter errors and a precise calibration model are crucial to the accuracy of the star tracker. Research in this field is relatively lacking a systematic and universal analysis up to now. This paper proposes in detail an approach for the synthetic error analysis of the star ...

  17. Use of portal radiography to increase accuracy of dose delivery in radiation therapy

    International Nuclear Information System (INIS)

    Port films were acquired for all radiation therapy patients (n = 132) treated over a thirteen month period to 1) assist in initial treatment field set-up on Day 1, 2) for quality assurance with a second port film taken on Day 7 of radiation therapy, and 3) as a means to document the radiation treatment field as a part of the patients permanent medical record. Port films were used for both patients treated with a definitive course of radiation (n = 97 patients), and those treated palliatively (n = 35 patients). The portal radiographs were valuable in terms of the initial set-up, and to correct for any positioning or other errors at the time of the one week recheck. Changes were made, based on the initial port film on Day 1, in 53 % and 57% of treatment fields for palliative and definitive radiation patients, respectively. The changes made in both definitively and palliatively irradiated patients were usually in field position, an increase in field size to include all of the tumor, or a decrease in field size to spare normal tissue. Fewer changes were necessary based on the Day 7 recheck port films, but these day-7 rechecks are recommended for quality control. Based on the high frequency of changes introduced because of the initial port film findings, it is recommended. that port films be incorporated on a routine basis in veterinary radiation therapy

  18. ssDNA Pairing Accuracy Increases When Abasic Sites Divide Nucleotides into Small Groups.

    Directory of Open Access Journals (Sweden)

    Alexandra Peacock-Villada

    Full Text Available Accurate sequence dependent pairing of single-stranded DNA (ssDNA molecules plays an important role in gene chips, DNA origami, and polymerase chain reactions. In many assays accurate pairing depends on mismatched sequences melting at lower temperatures than matched sequences; however, for sequences longer than ~10 nucleotides, single mismatches and correct matches have melting temperature differences of less than 3°C. We demonstrate that appropriately grouping of 35 bases in ssDNA using abasic sites increases the difference between the melting temperature of correct bases and the melting temperature of mismatched base pairings. Importantly, in the presence of appropriately spaced abasic sites mismatches near one end of a long dsDNA destabilize the annealing at the other end much more effectively than in systems without the abasic sites, suggesting that the dsDNA melts more uniformly in the presence of appropriately spaced abasic sites. In sum, the presence of appropriately spaced abasic sites allows temperature to more accurately discriminate correct base pairings from incorrect ones.

  19. Follow-up gliomas after radiotherapy: {sup 1}H MR spectroscopic imaging for increasing diagnostic accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Lichy, Matthias Philipp; Plathow, Christian [German Cancer Research Center, Department of Radiology, Heidelberg (Germany); University of Tuebingen, Department of Diagnostic Radiology, Tuebingen (Germany); Schulz-Ertner, Daniela [University of Heidelberg, Department of Radiation Therapy, Heidelberg (Germany); Kauczor, Hans-Ulrich [German Cancer Research Center, Department of Radiology, Heidelberg (Germany); Schlemmer, Heinz-Peter [University of Tuebingen, Department of Diagnostic Radiology, Tuebingen (Germany)

    2005-11-01

    We evaluated the value of magnetic resonance imaging (MRI) and the additional benefit of proton MR spectroscopic imaging ({sup 1}H SI) in patients with a new suspicious lesion after fractionated stereotactic radiotherapy (FSRT) of a glioma. Thirty-four patients with histologically proven astrocytoma WHO II-IV after treatment by FSRT and a new suspect lesion in the follow-up were included in this study. Data were analysed by three independent radiologists with different experience in {sup 1}H SI: Data were verified by clinical follow-up (PT, progressive tumour; nPT, non-progressive tumour) and a kappa analysis was performed. Sensitivity and specificity of T{sub 1} weighted (w) and T{sub 2}w MRI was compared (imaging at radiotherapy and follow-up) using further follow-up controls as gold standard and the additional benefit of {sup 1}H SI (imaging at follow-up) was calculated. Mean interval between last irradiation and detection of a suspicious lesion was 37 {+-} 32 months. Time to clinical evaluation was 13 {+-} 8 months. Interobserver agreement was significantly high in all analyses (kappa always >0.8, P < 0.05). T{sub 2}w imaging proved to be superior to contrast enhanced T{sub 1}w imaging in sensitivity (87.5 vs 81.25%) and specificity (85.7 vs 57.1%). Solitary {sup 1}H SI had similar results as T{sub 2}w (sensitivity 87.5%, specificity 71.4%). Taking all techniques into account, all PT were correctly diagnosed. (orig.)

  20. Using Meta-Analysis to Inform the Design of Subsequent Studies of Diagnostic Test Accuracy

    Science.gov (United States)

    Hinchliffe, Sally R.; Crowther, Michael J.; Phillips, Robert S.; Sutton, Alex J.

    2013-01-01

    An individual diagnostic accuracy study rarely provides enough information to make conclusive recommendations about the accuracy of a diagnostic test; particularly when the study is small. Meta-analysis methods provide a way of combining information from multiple studies, reducing uncertainty in the result and hopefully providing substantial…

  1. Cytopathological Analysis of Cyst Fluid Enhances Diagnostic Accuracy of Mucinous Pancreatic Cystic Neoplasms.

    Science.gov (United States)

    Utomo, Wesley K; Braat, Henri; Bruno, Marco J; van Eijck, Casper H J; Groot Koerkamp, Bas; Krak, Nanda C; van de Vreede, Adriaan; Fuhler, Gwenny M; Peppelenbosch, Maikel P; Biermann, Katharina

    2015-06-01

    Widespread use of cross-sectional imaging and increasing age of the general population has increased the number of detected pancreatic cystic lesions. However, several pathological entities with a variety in malignant potential have to be discriminated to allow clinical decision making. Discrimination between mucinous pancreatic cystic neoplasms (PCNs) and nonmucinous pancreatic lesions is the primary step in the clinical work-up, as malignant transformation is mostly associated with mucinous PCN. We performed a retrospective analysis of all resected PCN in our tertiary center from 2000 to 2014, to evaluate preoperative diagnostic performance and the results of implementation of the consensus guidelines over time. This was followed by a prospective cohort study of patients with an undefined pancreatic cyst, where the added value of cytopathological mucin evaluation to carcinoembryonic antigen (CEA) in cyst fluid for the discrimination of mucinous PCN and nonmucinous cysts was investigated. Retrospective analysis showed 115 patients operated for a PCN, with a correct preoperative classification in 96.2% of the patients. High-grade dysplasia or invasive carcinoma was observed in only 32.3% of mucinous PCN. In our prospective cohort (n = 71), 57.7% of patients were classified as having a mucinous PCN. CEA ≥ 192 ng/mL had an accuracy of 63.4%, and cytopathological mucin evaluation an accuracy of 73.0%. Combining these 2 tests further improved diagnostic accuracy of a mucinous PCN to 76.8%. CEA level and mucin evaluation were not predictive of the degree of dysplasia. These findings show that adding cytopathology to cyst fluid biochemistry improves discrimination between mucinous PCN and nonmucinous cysts.

  2. Tourniquet Test for Dengue Diagnosis: Systematic Review and Meta-analysis of Diagnostic Test Accuracy

    Science.gov (United States)

    Reid, Hamish; Thomas, Emma; Foster, Charlie; Darton, Thomas C.

    2016-01-01

    Background Dengue fever is a ubiquitous arboviral infection in tropical and sub-tropical regions, whose incidence has increased over recent decades. In the absence of a rapid point of care test, the clinical diagnosis of dengue is complex. The World Health Organisation has outlined diagnostic criteria for making the diagnosis of dengue infection, which includes the use of the tourniquet test (TT). Purpose To assess the quality of the evidence supporting the use of the TT and perform a diagnostic accuracy meta-analysis comparing the TT to antibody response measured by ELISA. Data Sources A comprehensive literature search was conducted in the following databases to April, 2016: MEDLINE (PubMed), EMBASE, Cochrane Central Register of Controlled Trials, BIOSIS, Web of Science, SCOPUS. Study Selection Studies comparing the diagnostic accuracy of the tourniquet test with ELISA for the diagnosis of dengue were included. Data Extraction Two independent authors extracted data using a standardized form. Data Synthesis A total of 16 studies with 28,739 participants were included in the meta-analysis. Pooled sensitivity for dengue diagnosis by TT was 58% (95% Confidence Interval (CI), 43%-71%) and the specificity was 71% (95% CI, 60%-80%). In the subgroup analysis sensitivity for non-severe dengue diagnosis was 55% (95% CI, 52%-59%) and the specificity was 63% (95% CI, 60%-66%), whilst sensitivity for dengue hemorrhagic fever diagnosis was 62% (95% CI, 53%-71%) and the specificity was 60% (95% CI, 48%-70%). Receiver-operator characteristics demonstrated a test accuracy (AUC) of 0.70 (95% CI, 0.66–0.74). Conclusion The tourniquet test is widely used in resource poor settings despite currently available evidence demonstrating only a marginal benefit in making a diagnosis of dengue infection alone. Registration The protocol for this systematic review was registered at PROSPERO: CRD42015020323. PMID:27486661

  3. Reliability and accuracy of three different computerized cephalometric analysis software.

    Science.gov (United States)

    Rusu, Oana; Petcu, Ana Elena; Drăgan, Eliza; Haba, Danisia; Moscalu, Mihaela; Zetu, Irina Nicoleta

    2015-01-01

    The aim of this investigation was to determine, compare and evaluate three different computerized tracing programs, where the lateral cephalograms were digitized on the screen. 39 randomly selected cephalometric radiographs were used in the present study. Three programs Planmeca Romexis® (Romexis 3.2.0., Helsinki, Finland), Orthalis (France) and AxCeph (A.C 2.3.0.74, Ljubljana, Slovenia) were evaluated. 12 skeletal, 9 dental and 3 soft tissue parameters were measured that consisted of 11 linear and 13 angular measurements. Statistical analysis was carried out using multivariate analysis of variance (MANOVA), Levene test, Tukey Honestly Significant Difference (HSD) test and Kruskal-Wallis test. The measurements obtained with the cephalometric analyses programs used in the study were reliable. PMID:25970975

  4. Spatial and Temporal Analysis on the Distribution of Active Radio-Frequency Identification (RFID Tracking Accuracy with the Kriging Method

    Directory of Open Access Journals (Sweden)

    Xin Liu

    2014-10-01

    Full Text Available Radio frequency identification (RFID technology has already been applied in a number of areas to facilitate the tracking process. However, the insufficient tracking accuracy of RFID is one of the problems that impedes its wider application. Previous studies focus on examining the accuracy of discrete points RFID, thereby leaving the tracking accuracy of the areas between the observed points unpredictable. In this study, spatial and temporal analysis is applied to interpolate the continuous distribution of RFID tracking accuracy based on the Kriging method. An implementation trial has been conducted in the loading and docking area in front of a warehouse to validate this approach. The results show that the weak signal area can be easily identified by the approach developed in the study. The optimum distance between two RFID readers and the effect of the sudden removal of readers are also presented by analysing the spatial and temporal variation of RFID tracking accuracy. This study reveals the correlation between the testing time and the stability of RFID tracking accuracy. Experimental results show that the proposed approach can be used to assist the RFID system setup process to increase tracking accuracy.

  5. ANALYSIS OF THE ACCURACY OF FIBRE-OPTIC STRAIN GAUGES

    OpenAIRE

    Dita Jiroutová; Miroslav Vokáč

    2013-01-01

    In recent years, the field of structure monitoring has been making increasing use of systems based on fiber-optic technologies. Fiber-optic technology offers many advantages, including higher quality measurements, greater reliability, easier installation and maintenance, insensitivity to the environment (mainly to the electromagnetic field), corrosion resistance, safety in explosive and flammable environments, the possibility of long-term monitoring and lower cost per lifetime. We have used S...

  6. Accuracy of Dynamic and Acoustic Analysis of Lightweight Panel Structures

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Dickow, Kristoffer Ahrens; Andersen, Lars Vabbersgaard;

    2012-01-01

    in such buildings is important. In the lowfrequency range, prediction of sound and vibration in building structures may be achieved by finite-element analysis (FEA). The aim of this paper is to compare the two commercial codes ABAQUS and ANSYS for FEA of an acoustic-structural coupling in a timber lightweight panel...... structure. For this purpose, modal analyses are carried out employing a fully coupled model of sound waves within an acoustic medium and vibrations in the structural part. The study concerns the frequency range 50–250 Hz....

  7. Axis-Exchanged Compensation and Gait Parameters Analysis for High Accuracy Indoor Pedestrian Dead Reckoning

    Directory of Open Access Journals (Sweden)

    Honghui Zhang

    2015-01-01

    Full Text Available Pedestrian dead reckoning (PDR is an effective way for navigation coupled with GNSS (Global Navigation Satellite System or weak GNSS signal environment like indoor scenario. However, indoor location with an accuracy of 1 to 2 meters determined by PDR based on MEMS-IMU is still very challenging. For one thing, heading estimation is an important problem in PDR because of the singularities. For another thing, walking distance estimation is also a critical problem for pedestrian walking with randomness. Based on the above two problems, this paper proposed axis-exchanged compensation and gait parameters analysis algorithm to improve the navigation accuracy. In detail, an axis-exchanged compensation factored quaternion algorithm is put forward first to overcome the singularities in heading estimation without increasing the amount of computation. Besides, real-time heading is updated by R-adaptive Kalman filter. Moreover, gait parameters analysis algorithm can be divided into two steps: cadence detection and step length estimation. Thus, a method of cadence classification and interval symmetry is proposed to detect the cadence accurately. Furthermore, a step length model adjusted by cadence is established for step length estimation. Compared to the traditional PDR navigation, experimental results showed that the error of navigation reduces 32.6%.

  8. Superior accuracy of model-based radiostereometric analysis for measurement of polyethylene wear

    DEFF Research Database (Denmark)

    Stilling, M; Kold, S; de Raedt, S;

    2012-01-01

    The accuracy and precision of two new methods of model-based radiostereometric analysis (RSA) were hypothesised to be superior to a plain radiograph method in the assessment of polyethylene (PE) wear.......The accuracy and precision of two new methods of model-based radiostereometric analysis (RSA) were hypothesised to be superior to a plain radiograph method in the assessment of polyethylene (PE) wear....

  9. Systematic review and meta-analysis of studies evaluating diagnostic test accuracy: A practical review for clinical researchers-Part II. general guidance and tips

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyung Won; Choi, Sang Hyun; Huh, Jimi; Park, Seong Ho [Dept. of Radiology, and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of); Lee, June Young [Dept. of Biostatistics, Korea University College of Medicine, Seoul (Korea, Republic of)

    2015-12-15

    Meta-analysis of diagnostic test accuracy studies differs from the usual meta-analysis of therapeutic/interventional studies in that, it is required to simultaneously analyze a pair of two outcome measures such as sensitivity and specificity, instead of a single outcome. Since sensitivity and specificity are generally inversely correlated and could be affected by a threshold effect, more sophisticated statistical methods are required for the meta-analysis of diagnostic test accuracy. Hierarchical models including the bivariate model and the hierarchical summary receiver operating characteristic model are increasingly being accepted as standard methods for meta-analysis of diagnostic test accuracy studies. We provide a conceptual review of statistical methods currently used and recommended for meta-analysis of diagnostic test accuracy studies. This article could serve as a methodological reference for those who perform systematic review and meta-analysis of diagnostic test accuracy studies.

  10. Diagnostic accuracy and tolerability of contrast enhanced CT colonoscopy in symptomatic patients with increased risk for colorectal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ozsunar, Yelda [Department of Radiology, School of Medicine, Adnan Menderes University, Aydin (Turkey)], E-mail: yozsunar@adu.edu.tr; Coskun, Guelten [Izmir Ataturk Egitim ve Arastirma Hastanesi, Izmir (Turkey); Delibas, Naciye; Uz, Burcin [Department of Radiology, School of Medicine, Adnan Menderes University, Aydin (Turkey); Yuekselen, Vahit [Department of Gastroenterology, School of Medicine, Adnan Menderes University, Aydin (Turkey)

    2009-09-15

    Objective: We compared the accuracy and tolerability of intravenous contrast enhanced spiral computed tomography colonography (CTC) and optical colonoscopy (OC) for the detection of colorectal neoplasia in symptomatic patients for colorectal neoplasia. Methods: A prospective study was performed in 48 patients with symptomatic patients with increased risk for colorectal cancer. Spiral CTC was performed in supine and prone positions after colonic cleansing. The axial, 2D MPR and virtual endoluminal views were analyzed. Results of spiral CTC were compared with OC which was done within 15 days. The psychometric tolerance test was asked to be performed for both CTC and colonoscopy after the procedure. Results: Ten lesions in 9 of 48 patients were found in CTC and confirmed with OC. Two masses and eight polyps, consisted of 1 tubulovillous, 1 tubular, 2 villous adenoma, 4 adenomatous polyp, 4 adenocarcinoma, were identified. Lesion prevalence was 21%. Sensitivity, specificity, accuracy, positive and negative predictive values were found 100%, 87%, 89%, 67% and 100%, respectively. Psychometric tolerance test showed that CTC significantly more comfortable comparing with OC (p = 0.00). CTC was the preferred method in 37% while OC was preferred in 6% of patients. In both techniques, the most unpleasant part was bowel cleansing. Conclusion: Contrast enhanced CTC is a highly accurate method in detecting colorectal lesions. Since the technique was found to be more comfortable and less time consuming compare to OE, it may be preferable in management of symptomatic patients with increased risk for colorectal cancer.

  11. Diagnostic accuracy and tolerability of contrast enhanced CT colonoscopy in symptomatic patients with increased risk for colorectal cancer

    International Nuclear Information System (INIS)

    Objective: We compared the accuracy and tolerability of intravenous contrast enhanced spiral computed tomography colonography (CTC) and optical colonoscopy (OC) for the detection of colorectal neoplasia in symptomatic patients for colorectal neoplasia. Methods: A prospective study was performed in 48 patients with symptomatic patients with increased risk for colorectal cancer. Spiral CTC was performed in supine and prone positions after colonic cleansing. The axial, 2D MPR and virtual endoluminal views were analyzed. Results of spiral CTC were compared with OC which was done within 15 days. The psychometric tolerance test was asked to be performed for both CTC and colonoscopy after the procedure. Results: Ten lesions in 9 of 48 patients were found in CTC and confirmed with OC. Two masses and eight polyps, consisted of 1 tubulovillous, 1 tubular, 2 villous adenoma, 4 adenomatous polyp, 4 adenocarcinoma, were identified. Lesion prevalence was 21%. Sensitivity, specificity, accuracy, positive and negative predictive values were found 100%, 87%, 89%, 67% and 100%, respectively. Psychometric tolerance test showed that CTC significantly more comfortable comparing with OC (p = 0.00). CTC was the preferred method in 37% while OC was preferred in 6% of patients. In both techniques, the most unpleasant part was bowel cleansing. Conclusion: Contrast enhanced CTC is a highly accurate method in detecting colorectal lesions. Since the technique was found to be more comfortable and less time consuming compare to OE, it may be preferable in management of symptomatic patients with increased risk for colorectal cancer.

  12. Toward Improved Force-Field Accuracy through Sensitivity Analysis of Host-Guest Binding Thermodynamics.

    Science.gov (United States)

    Yin, Jian; Fenley, Andrew T; Henriksen, Niel M; Gilson, Michael K

    2015-08-13

    Improving the capability of atomistic computer models to predict the thermodynamics of noncovalent binding is critical for successful structure-based drug design, and the accuracy of such calculations remains limited by nonoptimal force field parameters. Ideally, one would incorporate protein-ligand affinity data into force field parametrization, but this would be inefficient and costly. We now demonstrate that sensitivity analysis can be used to efficiently tune Lennard-Jones parameters of aqueous host-guest systems for increasingly accurate calculations of binding enthalpy. These results highlight the promise of a comprehensive use of calorimetric host-guest binding data, along with existing validation data sets, to improve force field parameters for the simulation of noncovalent binding, with the ultimate goal of making protein-ligand modeling more accurate and hence speeding drug discovery.

  13. The Accuracy of the Swallowing Kinematic Analysis at Various Movement Velocities of the Hyoid and Epiglottis

    OpenAIRE

    Lee, Seung Hak; Oh, Byung-Mo; Chun, Seong Min; Lee, Jung Chan; Min, Yusun; Bang, Sang-Heum; Kim, Hee Chan; Han, Tai Ryoon

    2013-01-01

    Objective To evaluate the accuracy of the swallowing kinematic analysis. Methods To evaluate the accuracy at various velocities of movement, we developed an instrumental model of linear and rotational movement, representing the physiologic movement of the hyoid and epiglottis, respectively. A still image of 8 objects was also used for measuring the length of the objects as a basic screening, and 18 movie files of the instrumental model, taken from videofluoroscopy with different velocities. T...

  14. Analysis of various modifications in spectra analysis on accuracy of dose reconstructions in EPR dosimetry in tooth enamel

    Energy Technology Data Exchange (ETDEWEB)

    Ciesielski, B., E-mail: bciesiel@gumed.edu.pl [Department of Physics and Biophysics, Medical University of Gdansk, Debinki 1, 80-211 Gdansk (Poland); Kaminska, J. [Department of Oncology and Radiotherapy, Medical University of Gdansk, Debinki 7, 80-211 Gdansk (Poland); Emerich, K. [Department of Paediatric Dentistry, Medical University of Gdansk, Orzeszkowej 18, 80-208 Gdansk (Poland)

    2011-09-15

    The results of EPR measurements performed due to our participation in the 4th International Comparison of EPR Dosimetry using tooth enamel were used to analyze the effects of modifications in numerical analysis of the measured spectra on precision and accuracy of reconstructed doses. The studied modifications included effects of: (1) a use of Mn{sup 2+} standard, (2) variations in experimental native background signals of tooth enamel used for dose reconstructions, (3) signal filtration, (4) subtraction of empty tube spectra, and (5) variations in the spectra ranges used for calculations (fitting windows). It was shown, that the use of a Mn standard, for normalization of intensities of the recorded signals in the spectra processing, strongly increased the dosimetric accuracy. The regression lines of the doses reconstructed using different background spectra against nominal doses, obtained without Mn standard, had slopes about 30% higher and their scatter range was about 2 times higher than the same parameters obtained when Mn standard was applied in the spectra processing. Accuracy of the measured doses characterized by root mean square deviations from the nominal doses was 71 mGy for calculations with Mn standard and 241 mGy without normalization to Mn lines. Despite the large beneficial effect of the use of Mn standard on accuracy (root mean square deviations of the data, slope of the regression lines), it did not significantly improve the dosimetry performance characterized by the critical dose and detection limit. The smoothing of the spectra by 9 point filtration resulted in 1.6% increase of the reconstructed doses. The subtraction of empty tube spectrum had no effect on precision and accuracy of the dose reconstruction. The performance parameters were also practically insensitive to a choice of a width of the spectral window used for the analysis, provided it encompassed the {approx}1.6 mT range covering the main peaks of the radiation induced signal in

  15. Accuracy Analysis of a Low-Cost Platform for Positioning and Navigation

    Science.gov (United States)

    Hofmann, S.; Kuntzsch, C.; Schulze, M. J.; Eggert, D.; Sester, M.

    2012-07-01

    This paper presents an accuracy analysis of a platform based on low-cost components for landmark-based navigation intended for research and teaching purposes. The proposed platform includes a LEGO MINDSTORMS NXT 2.0 kit, an Android-based Smartphone as well as a compact laser scanner Hokuyo URG-04LX. The robot is used in a small indoor environment, where GNSS is not available. Therefore, a landmark map was produced in advance, with the landmark positions provided to the robot. All steps of procedure to set up the platform are shown. The main focus of this paper is the reachable positioning accuracy, which was analyzed in this type of scenario depending on the accuracy of the reference landmarks and the directional and distance measuring accuracy of the laser scanner. Several experiments were carried out, demonstrating the practically achievable positioning accuracy. To evaluate the accuracy, ground truth was acquired using a total station. These results are compared to the theoretically achievable accuracies and the laser scanner's characteristics.

  16. Analysis of effect of pressure on surface accuracy for inflatable antenna

    Institute of Scientific and Technical Information of China (English)

    FU Li; DU Xing-wen; WAN Zhi-min

    2008-01-01

    Pressure is one of the important measures to control the surface accuracy of the reflector of inflatable antenna. Experiments and numerical analysis were carried out to highlight the effect of pressure on accuracy. The rapid, contactless and low-cost digital photogrammetry system (DPS) was employed to investigate the effect according to its lightweight and flexible characteristics. Measurement data show that the best pressure and the best area in this pressure can be obtained. Numerical analysis was conducted to check the measurement result. It is indicated that there is a little difference between them attributed to wrinkle. Results of analysis and experi-ments show that surface accuracy of the reflector can be adjusted by controlling pressure.

  17. Reliability analysis of kinematic accuracy for the elastic slider-crank mechanism

    Institute of Scientific and Technical Information of China (English)

    TUO Yaofei; CHEN Jianjun; ZHANG Chijiang; CHEN Yongqin

    2007-01-01

    This paper deals with the static and dynamic output kinematic accuracy of a group of elastic slider-crank mechanisms with the same design parameters by taking the bar length,the joint-gaps,the mass density,and the sectional and the physical parameters as random variables.According to the principle of linear pile-up of small displacement,the static and dynamic output kinematic errors are synthesized,and the reliability model of the kinematic accuracy of the mechanism is built.Through an example,a study of the influencing factors on the reliability of the output kinematic accuracy of the mechanism is made.The results obtained reveal the following facts:with the increase of the crank's rotating speed,the dynamic elastic deformation of the mechanism becomes the principal factor that greatly affects the reliability of the output kinematic accuracy of the mechanism.

  18. There's a Bug in Your Ear!: Using Technology to Increase the Accuracy of DTT Implementation

    Science.gov (United States)

    McKinney, Tracy; Vasquez, Eleazar, III.

    2014-01-01

    Many professionals have successfully implemented discrete trial teaching in the past. However, there have not been extensive studies examining the accuracy of discrete trial teaching implementation. This study investigated the use of Bug in Ear feedback on the accuracy of discrete trial teaching implementation among two pre-service teachers…

  19. Relative accuracy of three common methods of parentage analysis in natural populations

    KAUST Repository

    Harrison, Hugo B.

    2012-12-27

    Parentage studies and family reconstructions have become increasingly popular for investigating a range of evolutionary, ecological and behavioural processes in natural populations. However, a number of different assignment methods have emerged in common use and the accuracy of each may differ in relation to the number of loci examined, allelic diversity, incomplete sampling of all candidate parents and the presence of genotyping errors. Here, we examine how these factors affect the accuracy of three popular parentage inference methods (colony, famoz and an exclusion-Bayes\\' theorem approach by Christie (Molecular Ecology Resources, 2010a, 10, 115) to resolve true parent-offspring pairs using simulated data. Our findings demonstrate that accuracy increases with the number and diversity of loci. These were clearly the most important factors in obtaining accurate assignments explaining 75-90% of variance in overall accuracy across 60 simulated scenarios. Furthermore, the proportion of candidate parents sampled had a small but significant impact on the susceptibility of each method to either false-positive or false-negative assignments. Within the range of values simulated, colony outperformed FaMoz, which outperformed the exclusion-Bayes\\' theorem method. However, with 20 or more highly polymorphic loci, all methods could be applied with confidence. Our results show that for parentage inference in natural populations, careful consideration of the number and quality of markers will increase the accuracy of assignments and mitigate the effects of incomplete sampling of parental populations. © 2012 Blackwell Publishing Ltd.

  20. Analysis on the reconstruction accuracy of the Fitch method for inferring ancestral states

    Directory of Open Access Journals (Sweden)

    Grünewald Stefan

    2011-01-01

    Full Text Available Abstract Background As one of the most widely used parsimony methods for ancestral reconstruction, the Fitch method minimizes the total number of hypothetical substitutions along all branches of a tree to explain the evolution of a character. Due to the extensive usage of this method, it has become a scientific endeavor in recent years to study the reconstruction accuracies of the Fitch method. However, most studies are restricted to 2-state evolutionary models and a study for higher-state models is needed since DNA sequences take the format of 4-state series and protein sequences even have 20 states. Results In this paper, the ambiguous and unambiguous reconstruction accuracy of the Fitch method are studied for N-state evolutionary models. Given an arbitrary phylogenetic tree, a recurrence system is first presented to calculate iteratively the two accuracies. As complete binary tree and comb-shaped tree are the two extremal evolutionary tree topologies according to balance, we focus on the reconstruction accuracies on these two topologies and analyze their asymptotic properties. Then, 1000 Yule trees with 1024 leaves are generated and analyzed to simulate real evolutionary scenarios. It is known that more taxa not necessarily increase the reconstruction accuracies under 2-state models. The result under N-state models is also tested. Conclusions In a large tree with many leaves, the reconstruction accuracies of using all taxa are sometimes less than those of using a leaf subset under N-state models. For complete binary trees, there always exists an equilibrium interval [a, b] of conservation probability, in which the limiting ambiguous reconstruction accuracy equals to the probability of randomly picking a state. The value b decreases with the increase of the number of states, and it seems to converge. When the conservation probability is greater than b, the reconstruction accuracies of the Fitch method increase rapidly. The reconstruction

  1. The effect of pain on task switching: pain reduces accuracy and increases reaction times across multiple switching paradigms.

    Science.gov (United States)

    Attridge, Nina; Keogh, Edmund; Eccleston, Christopher

    2016-10-01

    Pain disrupts attention, which may have negative consequences for daily life for people with acute or chronic pain. It has been suggested that switching between tasks may leave us particularly susceptible to pain-related attentional disruption, because we need to disengage our attention from one task before shifting it onto another. Switching tasks typically elicit lower accuracies and/or longer reaction times when participants switch to a new task compared with repeating the same task, and pain may exacerbate this effect. We present 3 studies to test this hypothesis. In study 1, participants completed 2 versions of an alternating runs switching task under pain-free and thermal pain-induction conditions. Pain did not affect performance on either task. In studies 2 and 3, we examined 7 versions of the switching task using large general population samples, experiencing a variety of naturally occurring pain conditions, recruited and tested on the internet. On all tasks, participants with pain had longer reaction times on both switch and repeat trials compared with participants without pain, but pain did not increase switch costs. In studies 2 and 3, we also investigated the effects of type of pain, duration of pain, and analgesics on task performance. We conclude that pain has a small dampening effect on performance overall on switching tasks. This suggests that pain interrupts attention even when participants are engaged in a trial, not only when attention has been disengaged for shifting to a new task set.

  2. Increasing the accuracy of 18F-FDG PET/CT interpretation of "mildly positive" mediastinal nodes in the staging of non-small cell lung cancer.

    LENUS (Irish Health Repository)

    Moloney, F

    2014-05-01

    The aim of this study was to identify radiological factors that may reduce false-positive results and increase diagnostic accuracy when staging the mediastinum of patients with non-small cell lung carcinoma (NSCLC).

  3. The diagnostic accuracy of procalcitonin for bacteraemia: A systematic review and meta-analysis

    NARCIS (Netherlands)

    S.H. Hoeboer (Sandra); P.J. van der Geest (Patrick); D. Nieboer (Daan); A.B.J. Groeneveld (A.B. Johan)

    2015-01-01

    textabstractThe diagnostic use of procalcitonin for bacterial infections remains a matter of debate. Most studies have used ambiguous outcome measures such as sepsis instead of infection. We performed a systematic review and meta-analysis to investigate the diagnostic accuracy of procalcitonin for b

  4. Diagnostic accuracy of refractometry for assessing bovine colostrum quality: A systematic review and meta-analysis.

    Science.gov (United States)

    Buczinski, S; Vandeweerd, J M

    2016-09-01

    Provision of good quality colostrum [i.e., immunoglobulin G (IgG) concentration ≥50g/L] is the first step toward ensuring proper passive transfer of immunity for young calves. Precise quantification of colostrum IgG levels cannot be easily performed on the farm. Assessment of the refractive index using a Brix scale with a refractometer has been described as being highly correlated with IgG concentration in colostrum. The aim of this study was to perform a systematic review of the diagnostic accuracy of Brix refractometry to diagnose good quality colostrum. From 101 references initially obtain ed, 11 were included in the systematic review meta-analysis representing 4,251 colostrum samples. The prevalence of good colostrum samples with IgG ≥50g/L varied from 67.3 to 92.3% (median 77.9%). Specific estimates of accuracy [sensitivity (Se) and specificity (Sp)] were obtained for different reported cut-points using a hierarchical summary receiver operating characteristic curve model. For the cut-point of 22% (n=8 studies), Se=80.2% (95% CI: 71.1-87.0%) and Sp=82.6% (71.4-90.0%). Decreasing the cut-point to 18% increased Se [96.1% (91.8-98.2%)] and decreased Sp [54.5% (26.9-79.6%)]. Modeling the effect of these Brix accuracy estimates using a stochastic simulation and Bayes theorem showed that a positive result with the 22% Brix cut-point can be used to diagnose good quality colostrum (posttest probability of a good colostrum: 94.3% (90.7-96.9%). The posttest probability of good colostrum with a Brix value <18% was only 22.7% (12.3-39.2%). Based on this study, the 2 cut-points could be alternatively used to select good quality colostrum (sample with Brix ≥22%) or to discard poor quality colostrum (sample with Brix <18%). When sample results are between these 2 values, colostrum supplementation should be considered. PMID:27423958

  5. Evaluation of accuracy, precision and determination limit in the human hair analysis using neutron activation method

    International Nuclear Information System (INIS)

    The accuracy, precision and determination limit were evaluated for determination of Al, As, Br, Ca, Cd, Cl, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Na, Sb, Sc, Se, V and Zn in human head hair by instrumental neutron activation analysis. The precision was examined by analyzing human hair sample, and the results of relative standard deviations obtained ranged from 3.9 to 16.2%. The results accuracy was evaluated by using reference materials GBW 09101 Human Hair and NIES 5 Human Hair. Currie criterion was used for calculation of the determination limit. (author). 8 refs., 2 tabs

  6. Analysis of the Accuracy and Robustness of the Leap Motion Controller

    Directory of Open Access Journals (Sweden)

    Denis Fisseler

    2013-05-01

    Full Text Available The Leap Motion Controller is a new device for hand gesture controlled user interfaces with declared sub-millimeter accuracy. However, up to this point its capabilities in real environments have not been analyzed. Therefore, this paper presents a first study of a Leap Motion Controller. The main focus of attention is on the evaluation of the accuracy and repeatability. For an appropriate evaluation, a novel experimental setup was developed making use of an industrial robot with a reference pen allowing a position accuracy of 0.2 mm. Thereby, a deviation between a desired 3D position and the average measured positions below 0.2mmhas been obtained for static setups and of 1.2mmfor dynamic setups. Using the conclusion of this analysis can improve the development of applications for the Leap Motion controller in the field of Human-Computer Interaction.

  7. Analysis of the accuracy and robustness of the leap motion controller.

    Science.gov (United States)

    Weichert, Frank; Bachmann, Daniel; Rudak, Bartholomäus; Fisseler, Denis

    2013-05-14

    The Leap Motion Controller is a new device for hand gesture controlled user interfaces with declared sub-millimeter accuracy. However, up to this point its capabilities in real environments have not been analyzed. Therefore, this paper presents a first study of a Leap Motion Controller. The main focus of attention is on the evaluation of the accuracy and repeatability. For an appropriate evaluation, a novel experimental setup was developed making use of an industrial robot with a reference pen allowing a position accuracy of 0.2 mm. Thereby, a deviation between a desired 3D position and the average measured positions below 0.2 mm has been obtained for static setups and of 1.2 mm for dynamic setups. Using the conclusion of this analysis can improve the development of applications for the Leap Motion controller in the field of Human-Computer Interaction.

  8. Optical system error analysis and calibration method of high-accuracy star trackers.

    Science.gov (United States)

    Sun, Ting; Xing, Fei; You, Zheng

    2013-01-01

    The star tracker is a high-accuracy attitude measurement device widely used in spacecraft. Its performance depends largely on the precision of the optical system parameters. Therefore, the analysis of the optical system parameter errors and a precise calibration model are crucial to the accuracy of the star tracker. Research in this field is relatively lacking a systematic and universal analysis up to now. This paper proposes in detail an approach for the synthetic error analysis of the star tracker, without the complicated theoretical derivation. This approach can determine the error propagation relationship of the star tracker, and can build intuitively and systematically an error model. The analysis results can be used as a foundation and a guide for the optical design, calibration, and compensation of the star tracker. A calibration experiment is designed and conducted. Excellent calibration results are achieved based on the calibration model. To summarize, the error analysis approach and the calibration method are proved to be adequate and precise, and could provide an important guarantee for the design, manufacture, and measurement of high-accuracy star trackers. PMID:23567527

  9. Optical System Error Analysis and Calibration Method of High-Accuracy Star Trackers

    Directory of Open Access Journals (Sweden)

    Zheng You

    2013-04-01

    Full Text Available The star tracker is a high-accuracy attitude measurement device widely used in spacecraft. Its performance depends largely on the precision of the optical system parameters. Therefore, the analysis of the optical system parameter errors and a precise calibration model are crucial to the accuracy of the star tracker. Research in this field is relatively lacking a systematic and universal analysis up to now. This paper proposes in detail an approach for the synthetic error analysis of the star tracker, without the complicated theoretical derivation. This approach can determine the error propagation relationship of the star tracker, and can build intuitively and systematically an error model. The analysis results can be used as a foundation and a guide for the optical design, calibration, and compensation of the star tracker. A calibration experiment is designed and conducted. Excellent calibration results are achieved based on the calibration model. To summarize, the error analysis approach and the calibration method are proved to be adequate and precise, and could provide an important guarantee for the design, manufacture, and measurement of high-accuracy star trackers.

  10. Menu label accuracy at a university's foodservices. An exploratory recipe nutrition analysis.

    Science.gov (United States)

    Feldman, Charles; Murray, Douglas; Chavarria, Stephanie; Zhao, Hang

    2015-09-01

    The increase in the weight of American adults and children has been positively associated with the prevalence of the consumption of food-away-from-home. The objective was to assess the accuracy of claimed nutritional information of foods purchased in contracted foodservices located on the campus of an institution of higher education. Fifty popular food items were randomly collected from five main dining outlets located on a selected campus in the northeastern United States. The sampling was repeated three times on separate occasions for an aggregate total of 150 food samples. The samples were then weighed and assessed for nutrient composition (protein, cholesterol, fiber, carbohydrates, total fat, calories, sugar, and sodium) using nutrient analysis software. Results were compared with foodservices' published nutrition information. Two group comparisons, claimed and measured, were performed using the paired-sample t-test. Descriptive statistics were used as well. Among the nine nutritional values, six nutrients (total fat, sodium, protein, fiber, cholesterol, and weight) had more than 10% positive average discrepancies between measured and claimed values. Statistical significance of the variance was obtained in four of the eight categories of nutrient content: total fat, sodium, protein, and cholesterol (P nutritional information does not accurately reflect the declared values on menus, conclusions, decisions and actions based on posted information may not be valid.

  11. Whole-body predictors of wrist shot accuracy in ice hockey: a kinematic analysis.

    Science.gov (United States)

    Michaud-Paquette, Yannick; Magee, Patrick; Pearsall, David; Turcotte, René

    2011-03-01

    The purpose of this study was to identify joint angular kinematics that corresponds to shooting accuracy in the stationary ice hockey wrist shot. Twenty-four subjects participated in this study, each performing 10 successful shots on four shooting targets. An eight-camera infra-red motion capture system (240 Hz), along with passive reflective markers, was used to record motion of the joints, hockey stick, and puck throughout the performance of the wrist shot. A multiple regression analysis was carried out to examine whole-body kinematic variables with accuracy scores as the dependent variable. Significant accuracy predictors were identified in the lower limbs, torso and upper limbs. Interpretation of the kinematics suggests that characteristics such as a better stability of the base of support, momentum cancellation, proper trunk orientation and a more dynamic control of the lead arm throughout the wrist shot movement are presented as predictors for the accuracy outcome. These findings are substantial as they not only provide a framework for further analysis of motor control strategies using tools for accurate projection of objects, but more tangibly they may provide a comprehensive evidence-based guide to coaches and athletes for planned training to improve performance. PMID:21560748

  12. Running Accuracy Analysis of a 3-RRR Parallel Kinematic Machine Considering the Deformations of the Links

    Institute of Scientific and Technical Information of China (English)

    WANG Liping; JIANG Yao; LI Tiemin

    2014-01-01

    Parallel kinematic machines have drawn considerable attention and have been widely used in some special fields. However, high precision is still one of the challenges when they are used for advanced machine tools. One of the main reasons is that the kinematic chains of parallel kinematic machines are composed of elongated links that can easily suffer deformations, especially at high speeds and under heavy loads. A 3-RRR parallel kinematic machine is taken as a study object for investigating its accuracy with the consideration of the deformations of its links during the motion process. Based on the dynamic model constructed by the Newton-Euler method, all the inertia loads and constraint forces of the links are computed and their deformations are derived. Then the kinematic errors of the machine are derived with the consideration of the deformations of the links. Through further derivation, the accuracy of the machine is given in a simple explicit expression, which will be helpful to increase the calculating speed. The accuracy of this machine when following a selected circle path is simulated. The influences of magnitude of the maximum acceleration and external loads on the running accuracy of the machine are investigated. The results show that the external loads will deteriorate the accuracy of the machine tremendously when their direction coincides with the direction of the worst stiffness of the machine. The proposed method provides a solution for predicting the running accuracy of the parallel kinematic machines and can also be used in their design optimization as well as selection of suitable running parameters.

  13. Increased Proportion of Variance Explained and Prediction Accuracy of Survival of Breast Cancer Patients with Use of Whole-Genome Multiomic Profiles.

    Science.gov (United States)

    Vazquez, Ana I; Veturi, Yogasudha; Behring, Michael; Shrestha, Sadeep; Kirst, Matias; Resende, Marcio F R; de Los Campos, Gustavo

    2016-07-01

    Whole-genome multiomic profiles hold valuable information for the analysis and prediction of disease risk and progression. However, integrating high-dimensional multilayer omic data into risk-assessment models is statistically and computationally challenging. We describe a statistical framework, the Bayesian generalized additive model ((BGAM), and present software for integrating multilayer high-dimensional inputs into risk-assessment models. We used BGAM and data from The Cancer Genome Atlas for the analysis and prediction of survival after diagnosis of breast cancer. We developed a sequence of studies to (1) compare predictions based on single omics with those based on clinical covariates commonly used for the assessment of breast cancer patients (COV), (2) evaluate the benefits of combining COV and omics, (3) compare models based on (a) COV and gene expression profiles from oncogenes with (b) COV and whole-genome gene expression (WGGE) profiles, and (4) evaluate the impacts of combining multiple omics and their interactions. We report that (1) WGGE profiles and whole-genome methylation (METH) profiles offer more predictive power than any of the COV commonly used in clinical practice (e.g., subtype and stage), (2) adding WGGE or METH profiles to COV increases prediction accuracy, (3) the predictive power of WGGE profiles is considerably higher than that based on expression from large-effect oncogenes, and (4) the gain in prediction accuracy when combining multiple omics is consistent. Our results show the feasibility of omic integration and highlight the importance of WGGE and METH profiles in breast cancer, achieving gains of up to 7 points area under the curve (AUC) over the COV in some cases. PMID:27129736

  14. Toward Improved Force-Field Accuracy through Sensitivity Analysis of Host-Guest Binding Thermodynamics

    OpenAIRE

    Yin, Jian; Fenley, Andrew T.; Henriksen, Niel M.; Gilson, Michael K.

    2015-01-01

    Improving the capability of atomistic computer models to predict the thermodynamics of noncovalent binding is critical for successful structure-based drug design, and the accuracy of such calculations remains limited by non-optimal force field parameters. Ideally, one would incorporate protein-ligand affinity data into force field parametrization, but this would be inefficient and costly. We now demonstrate that sensitivity analysis can be used to efficiently tune Lennard-Jones parameters of ...

  15. The Analysis Of Accuracy Of Selected Methods Of Measuring The Thermal Resistance Of IGBTs

    Directory of Open Access Journals (Sweden)

    Górecki Krzysztof

    2015-09-01

    Full Text Available In the paper selected methods of measuring the thermal resistance of an IGBT (Insulated Gate Bipolar Transistor are presented and the accuracy of these methods is analysed. The analysis of the measurement error is performed and operating conditions of the considered device, at which each measurement method assures the least measuring error, are pointed out. Theoretical considerations are illustrated with some results of measurements and calculations.

  16. Superior accuracy of model-based radiostereometric analysis for measurement of polyethylene wear

    OpenAIRE

    Stilling, M.; Kold, S.; De Raedt, S.; Andersen, N. T.; Rahbek, O.; Søballe, K.

    2012-01-01

    Objectives The accuracy and precision of two new methods of model-based radiostereometric analysis (RSA) were hypothesised to be superior to a plain radiograph method in the assessment of polyethylene (PE) wear. Methods A phantom device was constructed to simulate three-dimensional (3D) PE wear. Images were obtained consecutively for each simulated wear position for each modality. Three commercially available packages were evaluated: model-based RSA using laser-scanned cup models (MB-RSA), mo...

  17. PASSIVE LOCATION AND ACCURACY ANALYSIS USING TDOA INFORMATION OF MULTI-STATIONS

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    A new exact, explicit, uniterative, and computationally efficient solution of nonlinear equation set for estimation of emitter position based on the time differences of arrival (TDOA) measured by multi-stations is proposed. The accuracy analysis of the location method is also presented. Finally performance evaluation results of emitter location by using TDOA information are illustrated by some graphs of Geometrical Dilution of Precision (GDOP) for various conditions in the specific surveillance region.

  18. Evaluation of the accuracy of analysis tools for atmospheric new particle formation

    OpenAIRE

    Korhonen, H.; S.-L. Sihto; V.-M. Kerminen; Lehtinen, K. E. J.

    2010-01-01

    Several mathematical tools have been developed in recent years to analyze new particle formation rates and to estimate nucleation rates and mechanisms at sub-3nm sizes from atmospheric aerosol data. Here we evaluate these analysis tools using 1239 numerical nucleation events for which the nucleation mechanism and formation rates were known exactly. The accuracy of the estimates of particle formation rate at 3 nm (J3) showed significant sensitivity to ...

  19. Evaluation of the accuracy of analysis tools for atmospheric new particle formation

    OpenAIRE

    Korhonen, H.; Sihto, S.-L.; Kerminen, V.-M.; Lehtinen, K. E. J.

    2011-01-01

    Several mathematical tools have been developed in recent years to analyze new particle formation rates and to estimate nucleation rates and mechanisms at sub-3 nm sizes from atmospheric aerosol data. Here we evaluate these analysis tools using 1239 numerical nucleation events for which the nucleation mechanism and formation rates were known exactly. The accuracy of the estimates of particle formation rate at 3 nm (J3) showed significant sensitivity to...

  20. Analysis of the Kinematic Accuracy Reliability of a 3-DOF Parallel Robot Manipulator

    Directory of Open Access Journals (Sweden)

    Guohua Cui

    2015-02-01

    Full Text Available Kinematic accuracy reliability is an important performance index in the evaluation of mechanism quality. By using a 3- DOF 3-PUU parallel robot manipulator as the research object, the position and orientation error model was derived by mapping the relation between the input and output of the mechanism. Three error sensitivity indexes that evaluate the kinematic accuracy of the parallel robot manipulator were obtained by adapting the singular value decomposition of the error translation matrix. Considering the influence of controllable and uncontrollable factors on the kinematic accuracy, the mathematical model of reliability based on random probability was employed. The measurement and calculation method for the evaluation of the mechanism’s kinematic reliability level was also provided. By analysing the mechanism’s errors and reliability, the law of surface error sensitivity for the location and structure parameters was obtained. The kinematic reliability of the parallel robot manipulator was statistically computed on the basis of the Monte Carlo simulation method. The reliability analysis of kinematic accuracy provides a theoretical basis for design optimization and error compensation.

  1. Analysis of machining accuracy during free form surface milling simulation for different milling strategies

    Science.gov (United States)

    Matras, A.; Kowalczyk, R.

    2014-11-01

    The analysis results of machining accuracy after the free form surface milling simulations (based on machining EN AW- 7075 alloys) for different machining strategies (Level Z, Radial, Square, Circular) are presented in the work. Particular milling simulations were performed using CAD/CAM Esprit software. The accuracy of obtained allowance is defined as a difference between the theoretical surface of work piece element (the surface designed in CAD software) and the machined surface after a milling simulation. The difference between two surfaces describes a value of roughness, which is as the result of tool shape mapping on the machined surface. Accuracy of the left allowance notifies in direct way a surface quality after the finish machining. Described methodology of usage CAD/CAM software can to let improve a time design of machining process for a free form surface milling by a 5-axis CNC milling machine with omitting to perform the item on a milling machine in order to measure the machining accuracy for the selected strategies and cutting data.

  2. Assembly accuracy analysis for small components with a planar surface in large-scale metrology

    International Nuclear Information System (INIS)

    Large-scale mechanical products, such as aircraft and rockets, consist of large numbers of small components, which introduce additional difficulty for assembly accuracy and error estimation. Planar surfaces as key product characteristics are usually utilised for positioning small components in the assembly process. This paper focuses on assembly accuracy analysis of small components with planar surfaces in large-scale volume products. To evaluate the accuracy of the assembly system, an error propagation model for measurement error and fixture error is proposed, based on the assumption that all errors are normally distributed. In this model, the general coordinate vector is adopted to represent the position of the components. The error transmission functions are simplified into a linear model, and the coordinates of the reference points are composed by theoretical value and random error. The installation of a Head-Up Display is taken as an example to analyse the assembly error of small components based on the propagation model. The result shows that the final coordination accuracy is mainly determined by measurement error of the planar surface in small components. To reduce the uncertainty of the plane measurement, an evaluation index of measurement strategy is presented. This index reflects the distribution of the sampling point set and can be calculated by an inertia moment matrix. Finally, a practical application is introduced for validating the evaluation index. (paper)

  3. Quantitative analysis of accuracy of an inertial/acoustic 6DOF tracking system in motion

    OpenAIRE

    Gilson, Stuart J.; Fitzgibbon, Andrew W.; Glennerster, Andrew

    2006-01-01

    An increasing number of neuroscience experiments are using virtual reality to provide a more immersive and less artificial experimental environment. This is particularly useful to navigation and three-dimensional scene perception experiments. Such experiments require accurate real-time tracking of the observer’s head in order to render the virtual scene. Here we present data on the accuracy of a commonly used 6 degree of freedom tracker (Intersense IS900) when it is moved in ways typical of v...

  4. The analysis accuracy assessment of CORINE land cover in the Iberian coast

    Science.gov (United States)

    Grullón, Yraida R.; Alhaddad, Bahaaeddin; Cladera, Josep R.

    2009-09-01

    Corine land cover 2000 (CLC2000) is a project jointly managed by the Joint Research Centre (JRC) and the European Environment Agency (EEA). Its aim is to update the Corine land cover database in Europe for the year 2000. Landsat-7 Enhanced Thematic Mapper (ETM) satellite images were used for the update and were acquired within the framework of the Image2000 project. Knowledge of the land status through the use of mapping CORINE Land Cover is of great importance to study of interaction land cover and land use categories in Europe scale. This paper presents the accuracy assessment methodology designed and implemented to validate the Iberian Coast CORINE Land Cover 2000 cartography. It presents an implementation of a new methodological concept for land cover data production, Object- Based classification, and automatic generalization to assess the thematic accuracy of CLC2000 by means of an independent data source based on the comparison of the land cover database with reference data derived from visual interpretation of high resolution satellite imageries for sample areas. In our case study, the existing Object-Based classifications are supported with digital maps and attribute databases. According to the quality tests performed, we computed the overall accuracy, and Kappa Coefficient. We will focus on the development of a methodology based on classification and generalization analysis for built-up areas that may improve the investigation. This study can be divided in these fundamental steps: -Extract artificial areas from land use Classifications based on Land-sat and Spot images. -Manuel interpretation for high resolution of multispectral images. -Determine the homogeneity of artificial areas by generalization process. -Overall accuracy, Kappa Coefficient and Special grid (fishnet) test for quality test. Finally, this paper will concentrate to illustrate the precise accuracy of CORINE dataset based on the above general steps.

  5. Analysis of accuracy in optical motion capture - A protocol for laboratory setup evaluation.

    Science.gov (United States)

    Eichelberger, Patric; Ferraro, Matteo; Minder, Ursina; Denton, Trevor; Blasimann, Angela; Krause, Fabian; Baur, Heiner

    2016-07-01

    Validity and reliability as scientific quality criteria have to be considered when using optical motion capture (OMC) for research purposes. Literature and standards recommend individual laboratory setup evaluation. However, system characteristics such as trueness, precision and uncertainty are often not addressed in scientific reports on 3D human movement analysis. One reason may be the lack of simple and practical methods for evaluating accuracy parameters of OMC. A protocol was developed for investigating the accuracy of an OMC system (Vicon, volume 5.5×1.2×2.0m(3)) with standard laboratory equipment and by means of trueness and uncertainty of marker distances. The study investigated the effects of number of cameras (6, 8 and 10), measurement height (foot, knee and hip) and movement condition (static and dynamic) on accuracy. Number of cameras, height and movement condition affected system accuracy significantly. For lower body assessment during level walking, the most favorable setting (10 cameras, foot region) revealed mean trueness and uncertainty to be -0.08 and 0.33mm, respectively. Dynamic accuracy cannot be predicted based on static error assessments. Dynamic procedures have to be used instead. The significant influence of the number of cameras and the measurement location suggests that instrumental errors should be evaluated in a laboratory- and task-specific manner. The use of standard laboratory equipment makes the proposed procedure widely applicable and it supports the setup process of OCM by simple functional error assessment. Careful system configuration and thorough measurement process control are needed to produce high-quality data. PMID:27230474

  6. Meta-Analysis: Diagnostic Accuracy of Anti-Cyclic Citrullinated Peptide Antibody for Juvenile Idiopathic Arthritis

    Directory of Open Access Journals (Sweden)

    Yan Wang

    2015-01-01

    Full Text Available Objective. To estimate the diagnostic accuracy of the anti-CCP test in JIA and to evaluate factors associated with higher accuracy. Methods. Two investigators performed an extensive search of the literature published between January 2000 and January 2014. The included articles were assessed by the Quality Assessment of Diagnostic Accuracy Studies tool. The meta-analysis was performed using a summary ROC (SROC curve and a bivariate random-effect model to estimate sensitivity and specificity across studies. Results. The bivariate meta-analysis yielded a pooled sensitivity and specificity of 10% (95% confidence interval (CI: 6.0%–15.0% and 99.0% (95% CI: 98.0%–100.0%. The area under the SROC curve was 0.96. Sensitivity estimates were highly heterogeneous, which was partially explained by the higher sensitivity in the rheumatoid factor-positive polyarthritis (RF+ PA subtype (48.0%; 95% CI: 31.0%–65.0% than in the other subtypes (17.0%; 95% CI: 14.0%–20.0% and the higher sensitivity of the Inova assay (17.0%; 95% CI: 14.0%–20.%% than the other assays (0.05%; 95% CI: 2.0%–11.0%. Conclusions. Anti-CCP antibody test has a high specificity for the diagnosis of JIA. The sensitivity of this test is low and varies across populations but is higher in RF+ PA than in other JIA subtypes.

  7. Diagnostic Accuracy of Xpert Test in Tuberculosis Detection: A Systematic Review and Meta-analysis

    Science.gov (United States)

    Kaur, Ravdeep; Kachroo, Kavita; Sharma, Jitendar Kumar; Vatturi, Satyanarayana Murthy; Dang, Amit

    2016-01-01

    Background: World Health Organization (WHO) recommends the use of Xpert MTB/RIF assay for rapid diagnosis of tuberculosis (TB) and detection of rifampicin resistance. This systematic review was done to know about the diagnostic accuracy and cost-effectiveness of the Xpert MTB/RIF assay. Methods: A systematic literature search was conducted in following databases: Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews, MEDLINE, PUBMED, Scopus, Science Direct and Google Scholar for relevant studies for studies published between 2010 and December 2014. Studies given in the systematic reviews were accessed separately and used for analysis. Selection of studies, data extraction and assessment of quality of included studies was performed independently by two reviewers. Studies evaluating the diagnostic accuracy of Xpert MTB/RIF assay among adult or predominantly adult patients (≥14 years), presumed to have pulmonary TB with or without HIV infection were included in the review. Also, studies that had assessed the diagnostic accuracy of Xpert MTB/RIF assay using sputum and other respiratory specimens were included. Results: The included studies had a low risk of any form of bias, showing that findings are of high scientific validity and credibility. Quantitative analysis of 37 included studies shows that Xpert MTB/RIF is an accurate diagnostic test for TB and detection of rifampicin resistance. Conclusion: Xpert MTB/RIF assay is a robust, sensitive and specific test for accurate diagnosis of tuberculosis as compared to conventional tests like culture and microscopic examination. PMID:27013842

  8. Diagnostic accuracy of xpert test in tuberculosis detection: A systematic review and meta-analysis

    Directory of Open Access Journals (Sweden)

    Ravdeep Kaur

    2016-01-01

    Full Text Available Background: World Health Organization (WHO recommends the use of Xpert MTB/RIF assay for rapid diagnosis of tuberculosis (TB and detection of rifampicin resistance. This systematic review was done to know about the diagnostic accuracy and cost-effectiveness of the Xpert MTB/RIF assay. Methods: A systematic literature search was conducted in following databases: Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews, MEDLINE, PUBMED, Scopus, Science Direct and Google Scholar for relevant studies for studies published between 2010 and December 2014. Studies given in the systematic reviews were accessed separately and used for analysis. Selection of studies, data extraction and assessment of quality of included studies was performed independently by two reviewers. Studies evaluating the diagnostic accuracy of Xpert MTB/RIF assay among adult or predominantly adult patients (≥14 years, presumed to have pulmonary TB with or without HIV infection were included in the review. Also, studies that had assessed the diagnostic accuracy of Xpert MTB/RIF assay using sputum and other respiratory specimens were included. Results: The included studies had a low risk of any form of bias, showing that findings are of high scientific validity and credibility. Quantitative analysis of 37 included studies shows that Xpert MTB/RIF is an accurate diagnostic test for TB and detection of rifampicin resistance. Conclusion: Xpert MTB/RIF assay is a robust, sensitive and specific test for accurate diagnosis of tuberculosis as compared to conventional tests like culture and microscopic examination.

  9. An Analysis of Base Station Location Accuracy within Mobile-Cellular Networks

    Directory of Open Access Journals (Sweden)

    Liam Smit

    2015-05-01

    Full Text Available An important feature within a mobile-cellular net- work is that the location of a cellphone can be determined. As long as the cellphone is powered on, the location of the cellphone can always be traced to at least the cell from which it is receiving, or last received, signal from the cellular network. Such network-based methods of estimating the location of a cellphone is useful in cases where the cellphone user is unable or unwilling to reveal his or her location, and have practical value in digital forensic investigations. This study investigates the accuracy of using mobile-cellular network base station information for estimating the location of cellphones. Through quantitative analysis of mobile-cellular network base station data, large variations between the best and worst accuracy of recorded location information is exposed. Thus, depending on the requirements, base station locations may or may not be accurate enough for a particular application.

  10. Application of data analysis techniques to nuclear reactor systems code to accuracy assessment

    International Nuclear Information System (INIS)

    An automated code assessment program (ACAP) has been developed by the authors to provide quantitative comparisons between nuclear reactor systems (NRS) code results and experimental measurements. This software was developed under subcontract to the United States Nuclear Regulatory Commission for use in its NRS code consolidation efforts. In this paper, background on the topic of NRS accuracy and uncertainty assessment is provided which motivates the development of and defines basic software requirements for ACAP. A survey of data analysis techniques was performed, focusing on the applicability of methods in the construction of NRS code-data comparison measures. The results of this review process, which further defined the scope, user interface and process for using ACAP are also summarized. A description of the software package and several sample applications to NRS data sets are provided. Its functionality and ability to provide objective accuracy assessment figures are demonstrated. (author)

  11. Error analysis to improve the speech recognition accuracy on Telugu language

    Indian Academy of Sciences (India)

    N Usha Rani; P N Girija

    2012-12-01

    Speech is one of the most important communication channels among the people. Speech Recognition occupies a prominent place in communication between the humans and machine. Several factors affect the accuracy of the speech recognition system. Much effort was involved to increase the accuracy of the speech recognition system, still erroneous output is generating in current speech recognition systems. Telugu language is one of the most widely spoken south Indian languages. In the proposed Telugu speech recognition system, errors obtained from decoder are analysed to improve the performance of the speech recognition system. Static pronunciation dictionary plays a key role in the speech recognition accuracy. Modification should be performed in the dictionary, which is used in the decoder of the speech recognition system. This modification reduces the number of the confusion pairs which improves the performance of the speech recognition system. Language model scores are also varied with this modification. Hit rate is considerably increased during this modification and false alarms have been changing during the modification of the pronunciation dictionary. Variations are observed in different error measures such as F-measures, error-rate and Word Error Rate (WER) by application of the proposed method.

  12. The Accuracy of Diagnostic Methods for Diabetic Retinopathy: A Systematic Review and Meta-Analysis.

    Directory of Open Access Journals (Sweden)

    Vicente Martínez-Vizcaíno

    Full Text Available The objective of this study was to evaluate the accuracy of the recommended glycemic measures for diagnosing diabetic retinopathy.We systematically searched MEDLINE, EMBASE, the Cochrane Library, and the Web of Science databases from inception to July 2015 for observational studies comparing the diagnostic accuracy of glycated hemoglobin (HbA1c, fasting plasma glucose (FPG, and 2-hour plasma glucose (2h-PG. Random effects models for the diagnostic odds ratio (dOR value computed by Moses' constant for a linear model and 95% CIs were used to calculate the accuracy of the test. Hierarchical summary receiver operating characteristic curves (HSROC were used to summarize the overall test performance.Eleven published studies were included in the meta-analysis. The pooled dOR values for the diagnosis of retinopathy were 16.32 (95% CI 13.86-19.22 for HbA1c and 4.87 (95% CI 4.39-5.40 for FPG. The area under the HSROC was 0.837 (95% CI 0.781-0.892 for HbA1c and 0.735 (95% CI 0.657-0.813 for FPG. The 95% confidence region for the point that summarizes the overall test performance of the included studies occurs where the cut-offs ranged from 6.1% (43.2 mmol/mol to 7.8% (61.7 mmol/mol for HbA1c and from 7.8 to 9.3 mmol/L for FPG. In the four studies that provided information regarding 2h-PG, the pooled accuracy estimates for HbA1c were similar to those of 2h-PG; the overall performance for HbA1c was superior to that for FPG.The three recommended tests for the diagnosis of type 2 diabetes in nonpregnant adults showed sufficient accuracy for their use in clinical settings, although the overall accuracy for the diagnosis of retinopathy was similar for HbA1c and 2h-PG, which were both more accurate than for FPG. Due to the variability and inconveniences of the glucose level-based methods, HbA1c appears to be the most appropriate method for the diagnosis diabetic retinopathy.

  13. Bayesian analysis of diagnostic test accuracy when disease state is unverified for some subjects.

    Science.gov (United States)

    Pennello, Gene A

    2011-09-01

    Studies of the accuracy of medical tests to diagnose the presence or absence of disease can suffer from an inability to verify the true disease state in everyone. When verification is missing at random (MAR), the missing data mechanism can be ignored in likelihood-based inference. However, this assumption may not hold even approximately. When verification is nonignorably missing, the most general model of the distribution of disease state, test result, and verification indicator is overparameterized. Parameters are only partially identified, creating regions of ignorance for maximum likelihood estimators. For studies of a single test, we use Bayesian analysis to implement the most general nonignorable model, a reduced nonignorable model with identifiable parameters, and the MAR model. Simple Gibbs sampling algorithms are derived that enable computation of the posterior distribution of test accuracy parameters. In particular, the posterior distribution is easily obtained for the most general nonignorable model, which makes relatively weak assumptions about the missing data mechanism. For this model, the posterior distribution combines two sources of uncertainty: ignorance in the estimation of partially identified parameters, and imprecision due to finite sampling variability. We compare the three models on data from a study of the accuracy of scintigraphy to diagnose liver disease.

  14. Improved accuracy for finite element structural analysis via an integrated force method

    Science.gov (United States)

    Patnaik, S. N.; Hopkins, D. A.; Aiello, R. A.; Berke, L.

    1992-01-01

    A comparative study was carried out to determine the accuracy of finite element analyses based on the stiffness method, a mixed method, and the new integrated force and dual integrated force methods. The numerical results were obtained with the following software: MSC/NASTRAN and ASKA for the stiffness method; an MHOST implementation method for the mixed method; and GIFT for the integrated force methods. The results indicate that on an overall basis, the stiffness and mixed methods present some limitations. The stiffness method generally requires a large number of elements in the model to achieve acceptable accuracy. The MHOST method tends to achieve a higher degree of accuracy for course models than does the stiffness method implemented by MSC/NASTRAN and ASKA. The two integrated force methods, which bestow simultaneous emphasis on stress equilibrium and strain compatibility, yield accurate solutions with fewer elements in a model. The full potential of these new integrated force methods remains largely unexploited, and they hold the promise of spawning new finite element structural analysis tools.

  15. Measurement methods and accuracy analysis of Chang'E-5 Panoramic Camera installation parameters

    Science.gov (United States)

    Yan, Wei; Ren, Xin; Liu, Jianjun; Tan, Xu; Wang, Wenrui; Chen, Wangli; Zhang, Xiaoxia; Li, Chunlai

    2016-04-01

    Chang'E-5 (CE-5) is a lunar probe for the third phase of China Lunar Exploration Project (CLEP), whose main scientific objectives are to implement lunar surface sampling and to return the samples back to the Earth. To achieve these goals, investigation of lunar surface topography and geological structure within sampling area seems to be extremely important. The Panoramic Camera (PCAM) is one of the payloads mounted on CE-5 lander. It consists of two optical systems which installed on a camera rotating platform. Optical images of sampling area can be obtained by PCAM in the form of a two-dimensional image and a stereo images pair can be formed by left and right PCAM images. Then lunar terrain can be reconstructed based on photogrammetry. Installation parameters of PCAM with respect to CE-5 lander are critical for the calculation of exterior orientation elements (EO) of PCAM images, which is used for lunar terrain reconstruction. In this paper, types of PCAM installation parameters and coordinate systems involved are defined. Measurement methods combining camera images and optical coordinate observations are studied for this work. Then research contents such as observation program and specific solution methods of installation parameters are introduced. Parametric solution accuracy is analyzed according to observations obtained by PCAM scientifically validated experiment, which is used to test the authenticity of PCAM detection process, ground data processing methods, product quality and so on. Analysis results show that the accuracy of the installation parameters affects the positional accuracy of corresponding image points of PCAM stereo images within 1 pixel. So the measurement methods and parameter accuracy studied in this paper meet the needs of engineering and scientific applications. Keywords: Chang'E-5 Mission; Panoramic Camera; Installation Parameters; Total Station; Coordinate Conversion

  16. Spot detection accuracy analysis in turbulent channel for free space optical communication

    Science.gov (United States)

    Liu, Yan-Fei; Dai, Yong-Hong; Yu, Sheng-Lin; Xin, Shan; Chen, Jing; Ai, Yong

    2015-10-01

    Increasingly importance has been taken seriously for high frame rate CMOS camera to optical communication acquisition pointing and tacking (APT) system, with its compact structure, easy to developed and adapted to beacon light spot detection in atmospheric channel. As spot position accuracy directly determines the performance of space optical communication, it is very important to design a high precision spot center algorithm. Usually spot location algorithm uses gravity algorithm, shape center capturing algorithm or self-adaption threshold algorithm. In experiments we analyzed the characteristics of the spots which transmitted through atmospheric turbulence and studied light transmission characteristics in turbulent channel. We carried out a beacon light detection experiments in a distance of 3.4km, collected the beacon spots on CMOS camera and signal light power. We calculated spot position with two different algorithm and compared the calculation accuracy between field dispersive spot and ideal Gaussian laser spot. Experiment research show that, gravity center algorithm should be more suitable for beacon beam spot which accuracy can be improved about 1.3 pixels for a Gaussian spot. But the shape center algorithm has higher precision. The reasons were analyzed which made an important preparation for subsequent testing.

  17. Nonlinearity for a parallel kinematic machine tool and its application to interpolation accuracy analysis

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This paper is concerned with the kinematic nonlinearity measure of parallel kinematic machine tool (PKM),which depends upon differential geometry curvature.The nonlinearity can be described by the curve of the solution locus and the equal interval input of joints mapping into inequable interval output of the end-effectors.Such curing and inequation can be measured by BW curvature.So the curvature can measure the nonlinearity of PKM indirectly.Then the distribution of BW curvature in the local area and the whole workspace are also discussed.An example of application to the interpolation accuracy analysis of PKM is given to illustrate the effectiveness of this approach.

  18. Accuracy of finite-element models for the stress analysis of multiple-holed moderator blocks

    International Nuclear Information System (INIS)

    Two steps have been taken to quantify and improve the accuracy in the analysis. First, the limitations of various approximation techniques have been studied with the aid of smaller benchmark problems containing fewer holes. Second, a new family of computer programs has been developed for handling such large problems. This paper describes the accuracy studies and the benchmark problems. A review is given of some proposed modeling techniques including local mesh refinement, homogenization, a special-purpose finite element, and substructuring. Some limitations of these approaches are discussed. The new finite element programs and the features that contribute to their efficiency are discussed. These include a standard architecture for out-of-core data processing and an equation solver that operates on a peripheral array processor. The central conclusions of the paper are: (1) modeling approximation methods such as local mesh refinement and homogenization tend to be unreliable, and they should be justified by a fine mesh benchmark analysis; and (2) finite element codes are now available that can achieve accurate solutions at a reasonable cost, and there is no longer a need to employ modeling approximations in the two-dimensional analysis of HTGR fuel elements. 10 figures

  19. Combined Scintigraphy and Tumor Marker Analysis Predicts Unfavorable Histopathology of Neuroblastic Tumors with High Accuracy.

    Directory of Open Access Journals (Sweden)

    Wolfgang Peter Fendler

    Full Text Available Our aim was to improve the prediction of unfavorable histopathology (UH in neuroblastic tumors through combined imaging and biochemical parameters.123I-MIBG SPECT and MRI was performed before surgical resection or biopsy in 47 consecutive pediatric patients with neuroblastic tumor. Semi-quantitative tumor-to-liver count-rate ratio (TLCRR, MRI tumor size and margins, urine catecholamine and NSE blood levels of neuron specific enolase (NSE were recorded. Accuracy of single and combined variables for prediction of UH was tested by ROC analysis with Bonferroni correction.34 of 47 patients had UH based on the International Neuroblastoma Pathology Classification (INPC. TLCRR and serum NSE both predicted UH with moderate accuracy. Optimal cut-off for TLCRR was 2.0, resulting in 68% sensitivity and 100% specificity (AUC-ROC 0.86, p < 0.001. Optimal cut-off for NSE was 25.8 ng/ml, resulting in 74% sensitivity and 85% specificity (AUC-ROC 0.81, p = 0.001. Combination of TLCRR/NSE criteria reduced false negative findings from 11/9 to only five, with improved sensitivity and specificity of 85% (AUC-ROC 0.85, p < 0.001.Strong 123I-MIBG uptake and high serum level of NSE were each predictive of UH. Combined analysis of both parameters improved the prediction of UH in patients with neuroblastic tumor. MRI parameters and urine catecholamine levels did not predict UH.

  20. Accuracy evaluation of a new stereophotogrammetry-based functional method for joint kinematic analysis in biomechanics.

    Science.gov (United States)

    Galetto, Maurizio; Gastaldi, Laura; Lisco, Giulia; Mastrogiacomo, Luca; Pastorelli, Stefano

    2014-11-01

    The human joint kinematics is an interesting topic in biomechanics and turns to be useful for the analysis of human movement in several fields. A crucial issue regards the assessment of joint parameters, like axes and centers of rotation, due to the direct influence on human motion patterns. A proper accuracy in the estimation of these parameters is hence required. On the whole, stereophotogrammetry-based predictive methods and, as an alternative, functional ones can be used to this end. This article presents a new functional algorithm for the assessment of knee joint parameters, based on a polycentric hinge model for the knee flexion-extension. The proposed algorithm is discussed, identifying its fields of application and its limits. The techniques for estimating the joint parameters from the metrological point of view are analyzed, so as to lay the groundwork for enhancing and eventually replacing predictive methods, currently used in the laboratories of human movement analysis. This article also presents an assessment of the accuracy associated with the whole process of measurement and joint parameters estimation. To this end, the presented functional method is tested through both computer simulations and a series of experimental laboratory tests in which swing motions were imposed to a polycentric mechanical analogue and a stereophotogrammetric system was used to record them. PMID:25500863

  1. Examining the accuracy of the infinite order sudden approximation using sensitivity analysis

    Science.gov (United States)

    Eno, Larry; Rabitz, Herschel

    1981-08-01

    A method is developed for assessing the accuracy of scattering observables calculated within the framework of the infinite order sudden (IOS) approximation. In particular, we focus on the energy sudden assumption of the IOS method and our approach involves the determination of the sensitivity of the IOS scattering matrix SIOS with respect to a parameter which reintroduces the internal energy operator ?0 into the IOS Hamiltonian. This procedure is an example of sensitivity analysis of missing model components (?0 in this case) in the reference Hamiltonian. In contrast to simple first-order perturbation theory a finite result is obtained for the effect of ?0 on SIOS. As an illustration, our method of analysis is applied to integral state-to-state cross sections for the scattering of an atom and rigid rotor. Results are generated within the He+H2 system and a comparison is made between IOS and coupled states cross sections and the corresponding IOS sensitivities. It is found that the sensitivity coefficients are very useful indicators of the accuracy of the IOS results. Finally, further developments and applications are discussed.

  2. Increasing Accuracy: A New Design and Algorithm for Automatically Measuring Weights, Travel Direction and Radio Frequency Identification (RFID) of Penguins.

    Science.gov (United States)

    Afanasyev, Vsevolod; Buldyrev, Sergey V; Dunn, Michael J; Robst, Jeremy; Preston, Mark; Bremner, Steve F; Briggs, Dirk R; Brown, Ruth; Adlard, Stacey; Peat, Helen J

    2015-01-01

    A fully automated weighbridge using a new algorithm and mechanics integrated with a Radio Frequency Identification System is described. It is currently in use collecting data on Macaroni penguins (Eudyptes chrysolophus) at Bird Island, South Georgia. The technology allows researchers to collect very large, highly accurate datasets of both penguin weight and direction of their travel into or out of a breeding colony, providing important contributory information to help understand penguin breeding success, reproductive output and availability of prey. Reliable discrimination between single and multiple penguin crossings is demonstrated. Passive radio frequency tags implanted into penguins allow researchers to match weight and trip direction to individual birds. Low unit and operation costs, low maintenance needs, simple operator requirements and accurate time stamping of every record are all important features of this type of weighbridge, as is its proven ability to operate 24 hours a day throughout a breeding season, regardless of temperature or weather conditions. Users are able to define required levels of accuracy by adjusting filters and raw data are automatically recorded and stored allowing for a range of processing options. This paper presents the underlying principles, design specification and system description, provides evidence of the weighbridge's accurate performance and demonstrates how its design is a significant improvement on existing systems.

  3. Increasing Accuracy: A New Design and Algorithm for Automatically Measuring Weights, Travel Direction and Radio Frequency Identification (RFID of Penguins.

    Directory of Open Access Journals (Sweden)

    Vsevolod Afanasyev

    Full Text Available A fully automated weighbridge using a new algorithm and mechanics integrated with a Radio Frequency Identification System is described. It is currently in use collecting data on Macaroni penguins (Eudyptes chrysolophus at Bird Island, South Georgia. The technology allows researchers to collect very large, highly accurate datasets of both penguin weight and direction of their travel into or out of a breeding colony, providing important contributory information to help understand penguin breeding success, reproductive output and availability of prey. Reliable discrimination between single and multiple penguin crossings is demonstrated. Passive radio frequency tags implanted into penguins allow researchers to match weight and trip direction to individual birds. Low unit and operation costs, low maintenance needs, simple operator requirements and accurate time stamping of every record are all important features of this type of weighbridge, as is its proven ability to operate 24 hours a day throughout a breeding season, regardless of temperature or weather conditions. Users are able to define required levels of accuracy by adjusting filters and raw data are automatically recorded and stored allowing for a range of processing options. This paper presents the underlying principles, design specification and system description, provides evidence of the weighbridge's accurate performance and demonstrates how its design is a significant improvement on existing systems.

  4. The accuracy of frozen section analysis in ultrasound- guided core needle biopsy of breast lesions

    Directory of Open Access Journals (Sweden)

    Riss Paul

    2009-09-01

    Full Text Available Abstract Background Limited data are available to evaluate the accuracy of frozen section analysis and ultrasound- guided core needle biopsy of the breast. Methods In a retrospective analysis data of 120 consecutive handheldultrasound- guided 14- gauge automated core needle biopsies (CNB in 109 consecutive patients with breast lesions between 2006 and 2007 were evaluated. Results In our outpatient clinic120 CNB were performed. In 59/120 (49.2% cases we compared histological diagnosis on frozen sections with those on paraffin sections of CNB and finally with the result of open biopsy. Of the cases 42/59 (71.2% were proved to be malignant and 17/59 (28.8% to be benign in the definitive histology. 2/59 (3.3% biopsies had a false negative frozen section result. No false positive results of the intraoperative frozen section analysis were obtained, resulting in a sensitivity, specificity and positive predicting value (PPV and negative predicting value (NPV of 95%, 100%, 100% and 90%, respectively. Histological and morphobiological parameters did not show up relevance for correct frozen section analysis. In cases of malignancy time between diagnosis and definitive treatment could not be reduced due to frozen section analysis. Conclusion The frozen section analysis of suspect breast lesions performed by CNB displays good sensitivity/specificity characteristics. Immediate investigations of CNB is an accurate diagnostic tool and an important step in reducing psychological strain by minimizing the period of uncertainty in patients with breast tumor.

  5. [An experimental study on human bitemarks digital analysis and its accuracy].

    Science.gov (United States)

    Wu, Yan; Chen, Xinmin; Sun, Dahong

    2005-10-01

    This experiment was designed to study the method of human bitemarks digital analysis and its accuracy. The human bitemarks were made on the dog skin by human dentition. The related parameters of human bitemarks and suspects criminal dentitions were digitally recorded and managed. The digital picture of human bitemark was obtained, and the dental study model, bite in wax and bitemark on pig skin of suspected criminal were scanned. The overlay was prepared with Adobe Photoshop 5. 5 and the parameters were measured with AutoCAD R14, then their matches were compared. The result shows that the human bitemarks digital analysis is a more accurate approach to human bitemarks identification. Three methods for collecting evidence dental study model, bite in wax and bitemark on pig skin all can be used as aids in forensic sciences. Dental study model is the most accurate one of all the three methods mentioned above.

  6. A Comparative Accuracy Analysis of Classification Methods in Determination of Cultivated Lands with Spot 5 Satellite Imagery

    Science.gov (United States)

    kaya, S.; Alganci, U.; Sertel, E.; Ustundag, B.

    2013-12-01

    A Comparative Accuracy Analysis of Classification Methods in Determination of Cultivated Lands with Spot 5 Satellite Imagery Ugur ALGANCI1, Sinasi KAYA1,2, Elif SERTEL1,2,Berk USTUNDAG3 1 ITU, Center for Satellite Communication and Remote Sensing, 34469, Maslak-Istanbul,Turkey 2 ITU, Department of Geomatics, 34469, Maslak-Istanbul, Turkey 3 ITU, Agricultural and Environmental Informatics Research Center,34469, Maslak-Istanbul,Turkey alganci@itu.edu.tr, kayasina@itu.edu.tr, sertele@itu.edu.tr, berk@berk.tc ABSTRACT Cultivated land determination and their area estimation are important tasks for agricultural management. Derived information is mostly used in agricultural policies and precision agriculture, in specifically; yield estimation, irrigation and fertilization management and farmers declaration verification etc. The use of satellite image in crop type identification and area estimate is common for two decades due to its capability of monitoring large areas, rapid data acquisition and spectral response to crop properties. With launch of high and very high spatial resolution optical satellites in the last decade, such kind of analysis have gained importance as they provide information at big scale. With increasing spatial resolution of satellite images, image classification methods to derive the information form them have become important with increase of the spectral heterogeneity within land objects. In this research, pixel based classification with maximum likelihood algorithm and object based classification with nearest neighbor algorithm were applied to 2012 dated 2.5 m resolution SPOT 5 satellite images in order to investigate the accuracy of these methods in determination of cotton and corn planted lands and their area estimation. Study area was selected in Sanliurfa Province located on Southeastern Turkey that contributes to Turkey's agricultural production in a major way. Classification results were compared in terms of crop type identification using

  7. Sensitivity Analysis for Characterizing the Accuracy and Precision of JEM/SMILES Mesospheric O3

    Science.gov (United States)

    Esmaeili Mahani, M.; Baron, P.; Kasai, Y.; Murata, I.; Kasaba, Y.

    2011-12-01

    The main purpose of this study is to evaluate the Superconducting sub-Millimeter Limb Emission Sounder (SMILES) measurements of mesospheric ozone, O3. As the first step, the error due to the impact of Mesospheric Temperature Inversions (MTIs) on ozone retrieval has been determined. The impacts of other parameters such as pressure variability, solar events, and etc. on mesospheric O3 will also be investigated. Ozone, is known to be important due to the stratospheric O3 layer protection of life on Earth by absorbing harmful UV radiations. However, O3 chemistry can be studied purely in the mesosphere without distraction of heterogeneous situation and dynamical variations due to the short lifetime of O3 in this region. Mesospheric ozone is produced by the photo-dissociation of O2 and the subsequent reaction of O with O2. Diurnal and semi-diurnal variations of mesospheric ozone are associated with variations in solar activity. The amplitude of the diurnal variation increases from a few percent at an altitude of 50 km, to about 80 percent at 70 km. Although despite the apparent simplicity of this situation, significant disagreements exist between the predictions from the existing models and observations, which need to be resolved. SMILES is a highly sensitive radiometer with a few to several tens percent of precision from upper troposphere to the mesosphere. SMILES was developed by the Japanese Aerospace eXploration Agency (JAXA) and the National Institute of Information and Communications Technology (NICT) located at the Japanese Experiment Module (JEM) on the International Space Station (ISS). SMILES has successfully measured the vertical distributions and the diurnal variations of various atmospheric species in the latitude range of 38S to 65N from October 2009 to April 2010. A sensitivity analysis is being conducted to investigate the expected precision and accuracy of the mesospheric O3 profiles (from 50 to 90 km height) due to the impact of Mesospheric Temperature

  8. Photogrammetric determinaiton of coordinates and deformations analysis of the accuracy of this method

    Energy Technology Data Exchange (ETDEWEB)

    Korablev, D.P.; Fomichev, L.V.; Trunin, A.P.

    1979-01-01

    The photogrammetric method for determining coordinates and deformation, developed at the VNIMI, is based on the analytic determination of the coordinates of points of the sample from measurements of a single stereogram or photograph. The measurements are closely controlled. Calculations are done on a computer. In addition to calculating the point coordinates and various deformation values (vertical and horizontal displacements, slopes, deflections etc.), the accuracy of the results is evaluated: the standard deviation per unit mass, the rms errors of the adjusted values of photo orientation on real photographs and analytical models. The following conclusions and assumptions were obtained on the basis of these studies: 1. When finding the deformation of a flat object, if the points of the last deformation show practically no displacement in the direction normal to the flat surface, then the photos should be taken separately and processed by analytical transformational or by the parallax method, measured from stereograms with a ''time basis''. 2. Then using convergent photography, there is a significant increase in the accuracy of the coordinate determination in the direction perpendicular to the photographic reference line, while there is almost no change in accuracy along the two other axes when compared to normal photography. Optimal symmetric-convergent exposure has a convergence angle of 60 to 120 /sup 0/ and a 1.5 to 2 ratio of the photographic reference line to the average distance to the object (along a normal to the reference). The stereogram of the symmetric-convergent photography for 100% coverage of the photographs encompasses an area two to three times larger than the usual steoegram. 3. The distribution of the reference points should be considered optimal when they bound the working area of the photograph (stereogram). When photographing volumes, they bound the object in the plan and side views.

  9. Diagnostic accuracy of quantitative 99mTc-MIBI scintimammography according to ROC curve analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J. H.; Lee, H. K.; Seo, J. W.; Cho, N. S.; Cha, K. H.; Lee, T. H. [Gachon Medical College, Gil Medical Center, Inchon (Korea, Republic of)

    1998-07-01

    99mTc-sestamibi scintimammography (SMM) has been shown to be a useful diagnostic test in the detection of breast cancer and the receiver operating characteristic (ROC) curve analysis provides detailed information of a diagnostic test. The purpose of this study was to evaluate the feasibility and efficacy of quantitative indices of SMM in the detection of malignant breast lesions according to ROC analysis. Prone anterior, lateral planar and supine SPECT imagings were performed on 75 female patients (mean age=43.4 yr) with breast mass (size{>=}0.8cm) after intravenous injection of 20-30 mCi 99mTc-sestamibi. 45 Malignant (Invasive ductal ca(36), Inv lobular ca(5), Inv duc + lob (1), Inv tubular ca (3)) and 30 benign (fibroadenoma (13), fib cyst(12), Fat necrosis(3), papilloma(1), paraffinoma (1)) lesions were histologically proven. Data were analyzed by creating three regions of interest (ROIs) over designated areas: lesion, normal breast and right chest wall. Lesion to normal (L/NL) and lesion to chest wall (L/CW) ratios were calculated for each patient both on the planar and SPECT. The area under the ROC curve (AUC) was calculated and compared among four semiquantitative indices and an average scintimammographic index (SMM(mean)) from arithmatic mean. ROC curve analysis revealed planar L/N, SPECT L/N and L/CW ratios provide comparable better diagnostic accuracies for detection of breast cancer than planar L/CW ratio (p<0.05), respectively. For quantitative SMM of 75 lesions, malignancy rate was 60%, and Sensitivity, Specificity, Positive Predictive Value, Negative Predictive Value and Accuracy were 0.78, 0.77, 0.84, 0.72 and 0.77, respectively. Quantitative SMM is an useful objective method for differentiating malignant from benign breast lesions.

  10. Diagnostic test accuracy of glutamate dehydrogenase for Clostridium difficile: Systematic review and meta-analysis.

    Science.gov (United States)

    Arimoto, Jun; Horita, Nobuyuki; Kato, Shingo; Fuyuki, Akiko; Higurashi, Takuma; Ohkubo, Hidenori; Endo, Hiroki; Takashi, Nonaka; Kaneko, Takeshi; Nakajima, Atsushi

    2016-01-01

    We performed this systematic review and meta-analysis to assess the diagnostic accuracy of detecting glutamate dehydrogenase (GDH) for Clostridium difficile infection (CDI) based on the hierarchical model. Two investigators electrically searched four databases. Reference tests were stool cell cytotoxicity neutralization assay (CCNA) and stool toxigenic culture (TC). To assess the overall accuracy, we calculated the diagnostic odds ratio (DOR) using a DerSimonian-Laird random-model and area the under hierarchical summary receiver operating characteristics (AUC) using Holling's proportional hazard models. The summary estimate of the sensitivity and the specificity were obtained using the bivariate model. According to 42 reports consisting of 3055 reference positive comparisons, and 26188 reference negative comparisons, the DOR was 115 (95%CI: 77-172, I(2) = 12.0%) and the AUC was 0.970 (95%CI: 0.958-0.982). The summary estimate of sensitivity and specificity were 0.911 (95%CI: 0.871-0.940) and 0.912 (95%CI: 0.892-0.928). The positive and negative likelihood ratios were 10.4 (95%CI 8.4-12.7) and 0.098 (95%CI 0.066-0.142), respectively. Detecting GDH for the diagnosis of CDI had both high sensitivity and specificity. Considering its low cost and prevalence, it is appropriate for a screening test for CDI. PMID:27418431

  11. Reconstruction Accuracy Assessment of Surface and Underwater 3D Motion Analysis: A New Approach

    Science.gov (United States)

    de Jesus, Kelly; de Jesus, Karla; Figueiredo, Pedro; Vilas-Boas, João Paulo; Fernandes, Ricardo Jorge; Machado, Leandro José

    2015-01-01

    This study assessed accuracy of surface and underwater 3D reconstruction of a calibration volume with and without homography. A calibration volume (6000 × 2000 × 2500 mm) with 236 markers (64 above and 88 underwater control points—with 8 common points at water surface—and 92 validation points) was positioned on a 25 m swimming pool and recorded with two surface and four underwater cameras. Planar homography estimation for each calibration plane was computed to perform image rectification. Direct linear transformation algorithm for 3D reconstruction was applied, using 1600000 different combinations of 32 and 44 points out of the 64 and 88 control points for surface and underwater markers (resp.). Root Mean Square (RMS) error with homography of control and validations points was lower than without it for surface and underwater cameras (P ≤ 0.03). With homography, RMS errors of control and validation points were similar between surface and underwater cameras (P ≥ 0.47). Without homography, RMS error of control points was greater for underwater than surface cameras (P ≤ 0.04) and the opposite was observed for validation points (P ≤ 0.04). It is recommended that future studies using 3D reconstruction should include homography to improve swimming movement analysis accuracy. PMID:26175796

  12. Diagnostic test accuracy of glutamate dehydrogenase for Clostridium difficile: Systematic review and meta-analysis.

    Science.gov (United States)

    Arimoto, Jun; Horita, Nobuyuki; Kato, Shingo; Fuyuki, Akiko; Higurashi, Takuma; Ohkubo, Hidenori; Endo, Hiroki; Takashi, Nonaka; Kaneko, Takeshi; Nakajima, Atsushi

    2016-07-15

    We performed this systematic review and meta-analysis to assess the diagnostic accuracy of detecting glutamate dehydrogenase (GDH) for Clostridium difficile infection (CDI) based on the hierarchical model. Two investigators electrically searched four databases. Reference tests were stool cell cytotoxicity neutralization assay (CCNA) and stool toxigenic culture (TC). To assess the overall accuracy, we calculated the diagnostic odds ratio (DOR) using a DerSimonian-Laird random-model and area the under hierarchical summary receiver operating characteristics (AUC) using Holling's proportional hazard models. The summary estimate of the sensitivity and the specificity were obtained using the bivariate model. According to 42 reports consisting of 3055 reference positive comparisons, and 26188 reference negative comparisons, the DOR was 115 (95%CI: 77-172, I(2) = 12.0%) and the AUC was 0.970 (95%CI: 0.958-0.982). The summary estimate of sensitivity and specificity were 0.911 (95%CI: 0.871-0.940) and 0.912 (95%CI: 0.892-0.928). The positive and negative likelihood ratios were 10.4 (95%CI 8.4-12.7) and 0.098 (95%CI 0.066-0.142), respectively. Detecting GDH for the diagnosis of CDI had both high sensitivity and specificity. Considering its low cost and prevalence, it is appropriate for a screening test for CDI.

  13. Quantitative analysis of X-band weather radar attenuation correction accuracy

    Directory of Open Access Journals (Sweden)

    A. Berne

    2006-01-01

    Full Text Available At short wavelengths, especially C-, X-, and K-band, weather radar signals are attenuated by the precipitation along their paths. This constitutes a major source of error for radar rainfall estimation, in particular for intense precipitation. A recently developed stochastic simulator of range profiles of raindrop size distributions (DSD provides a controlled experiment framework to investigate the accuracy and robustness of attenuation correction algorithms. The work presented here focuses on the quantification of the influence of uncertainties concerning radar calibration, the parameterization of power law relations between the integral variables (radar reflectivity Z and specific attenuation k, and total path integrated attenuation (PIA estimates at X-band. The analysis concerns single frequency, incoherent and non-polarimetric radar systems. Two attenuation correction algorithms, based on a forward and a backward implementation respectively, are studied. From DSD range profiles, the corresponding profiles of integral radar variables are derived. Using a Monte Carlo approach, the accuracy and robustness of the two algorithms are quantified for the different sources of error previously mentioned. This framework of realistic DSD variability provides a robust way to confirm that, under realistic assumptions concerning the PIA estimation uncertainty, the forward algorithm outperforms the backward algorithm for PIA values below 10 dB.

  14. Reconstruction Accuracy Assessment of Surface and Underwater 3D Motion Analysis: A New Approach

    Directory of Open Access Journals (Sweden)

    Kelly de Jesus

    2015-01-01

    Full Text Available This study assessed accuracy of surface and underwater 3D reconstruction of a calibration volume with and without homography. A calibration volume (6000 × 2000 × 2500 mm with 236 markers (64 above and 88 underwater control points—with 8 common points at water surface—and 92 validation points was positioned on a 25 m swimming pool and recorded with two surface and four underwater cameras. Planar homography estimation for each calibration plane was computed to perform image rectification. Direct linear transformation algorithm for 3D reconstruction was applied, using 1600000 different combinations of 32 and 44 points out of the 64 and 88 control points for surface and underwater markers (resp.. Root Mean Square (RMS error with homography of control and validations points was lower than without it for surface and underwater cameras (P≤0.03. With homography, RMS errors of control and validation points were similar between surface and underwater cameras (P≥0.47. Without homography, RMS error of control points was greater for underwater than surface cameras (P≤0.04 and the opposite was observed for validation points (P≤0.04. It is recommended that future studies using 3D reconstruction should include homography to improve swimming movement analysis accuracy.

  15. Accuracy and Repeatability of the Gait Analysis by the WalkinSense System

    Directory of Open Access Journals (Sweden)

    Marcelo P. de Castro

    2014-01-01

    Full Text Available WalkinSense is a new device designed to monitor walking. The aim of this study was to measure the accuracy and repeatability of the gait analysis performed by the WalkinSense system. Descriptions of values recorded by WalkinSense depicting typical gait in adults are also presented. A bench experiment using the Trublu calibration device was conducted to statically test the WalkinSense. Following this, a dynamic test was carried out overlapping the WalkinSense and the Pedar insoles in 40 healthy participants during walking. Pressure peak, pressure peak time, pressure-time integral, and mean pressure at eight-foot regions were calculated. In the bench experiments, the repeatability (i among the WalkinSense sensors (within, (ii between two WalkinSense devices, and (iii between the WalkinSense and the Trublu devices was excellent. In the dynamic tests, the repeatability of the WalkinSense (i between stances in the same trial (within-trial and (ii between trials was also excellent (ICC > 0.90. When the eight-foot regions were analyzed separately, the within-trial and between-trials repeatability was good-to-excellent in 88% (ICC > 0.80 of the data and fair in 11%. In short, the data suggest that the WalkinSense has good-to-excellent levels of accuracy and repeatability for plantar pressure variables.

  16. Accuracy and Repeatability of the Gait Analysis by the WalkinSense System

    Science.gov (United States)

    de Castro, Marcelo P.; Soares, Denise P.; Borgonovo-Santos, Márcio; Sousa, Filipa; Vilas-Boas, João Paulo

    2014-01-01

    WalkinSense is a new device designed to monitor walking. The aim of this study was to measure the accuracy and repeatability of the gait analysis performed by the WalkinSense system. Descriptions of values recorded by WalkinSense depicting typical gait in adults are also presented. A bench experiment using the Trublu calibration device was conducted to statically test the WalkinSense. Following this, a dynamic test was carried out overlapping the WalkinSense and the Pedar insoles in 40 healthy participants during walking. Pressure peak, pressure peak time, pressure-time integral, and mean pressure at eight-foot regions were calculated. In the bench experiments, the repeatability (i) among the WalkinSense sensors (within), (ii) between two WalkinSense devices, and (iii) between the WalkinSense and the Trublu devices was excellent. In the dynamic tests, the repeatability of the WalkinSense (i) between stances in the same trial (within-trial) and (ii) between trials was also excellent (ICC > 0.90). When the eight-foot regions were analyzed separately, the within-trial and between-trials repeatability was good-to-excellent in 88% (ICC > 0.80) of the data and fair in 11%. In short, the data suggest that the WalkinSense has good-to-excellent levels of accuracy and repeatability for plantar pressure variables. PMID:24701570

  17. Two or More Synchronous Combination of Noninvasive Tests to Increase Accuracy of Liver Fibrosis Assessement in Chronic Hepatitis C; Results From a Cohort of 446 Patients

    Directory of Open Access Journals (Sweden)

    Dana Crisan

    2012-03-01

    Full Text Available Background: The prediction of fibrosis is an essential part of the assessment and management of patients with chronic liver disease. Non-invasive tests (NITs have a number of advantages over the traditional standard of fibrosis assessment by liver biopsy, including safety, cost-effectiveness, and widespread accessibility.Objectives: The aim of this study was to determine the accuracy of certain biomarkers and transient elastography (TE alone or in combination to predict the stage of liver fibrosis in chronic hepatitis C (CHC. Also, we examined whether the combination of certain biomarkers and TE could increase the diagnostic accuracy of liver fibrosis assessment.Patients and Methods: A total of 446 patients who were previously diagnosed with CHC were included in the study. In the study group, 6 blood-based scores (APRI, Forns, Fib-4, Hepascore, FibroTest, and Fibrometer were calculated, and TE was performed to validate the stage of fibrosis, compared with liver biopsy (LB as the standard.Results: Significant fibrosis (F ≥ 2 was predicted with an AUROC of 0.727, 0.680, 0.714, 0.778, 0.688, 0.797, and 0.751 for the APRI, Forns, Fib-4, FibroTest, Hepascore, and Fibrometer scores and TE (Fibroscan, respectively. Severe fibrosis (F ≥ 3 was predicted, with AUROCs ranging between 0.705 and 0.811 for Hepascore and Fibrometer, respectively. Of the biomarkers, Fibrometer had the highest AUROC value in predicting both significant and severe fibrosis. The combination of APRI or FIB-4 with Fibrometer increased the diagnostic accuracy for significant fibrosis (from 69.07 to 82.27 for APRI, P = 0.001 and from 57.74 to 81.33, P = 0.001 for Fib-4. Combining APRI or Fib-4 with TE also increased the diagnostic accuracy (from 69.07 to 80.70%, P = 0.001 for APRI and from 57.74 to 81.33%, P = 0.001 for Fib-4 for significant fibrosis. The association that included Fibrotest was also reliable for the improvement of diagnostic accuracy. These combinations were more

  18. Increase of accuracy of definition of temperature by sensors of fire alarms in real conditions of fire on objects

    OpenAIRE

    Andronov, Vladimir; Pospelov, Boris; Rybka, Evgenіy

    2016-01-01

    The theoretical analysis of the generalised circuit of the thermal sensor has shown that it is a converter of information of the resistive sensitive element into the corresponding voltage, which is carried out by the bridge measuring circuit. The dynamic model of the generalised circuit of the thermal sensor of fire alarm is presented in the form of the differential equations in the state space for the thermoresistive sensitive element in the form of a thin plate is developed on the basis of ...

  19. Quantum Monte Carlo for Noncovalent Interactions: Analysis of Protocols and Simplified Scheme Attaining Benchmark Accuracy

    CERN Document Server

    Dubecký, Matúš; Jurečka, Petr; Mitas, Lubos; Hobza, Pavel; Otyepka, Michal

    2014-01-01

    Reliable theoretical predictions of noncovalent interaction energies, which are important e.g. in drug-design and hydrogen-storage applications, belong to longstanding challenges of contemporary quantum chemistry. In this respect, the fixed-node diffusion Monte Carlo (FN-DMC) is a promising alternative to the commonly used ``gold standard'' coupled-cluster CCSD(T)/CBS method for its benchmark accuracy and favourable scaling, in contrast to other correlated wave function approaches. This work is focused on the analysis of protocols and possible tradeoffs for FN-DMC estimations of noncovalent interaction energies and proposes a significantly more efficient yet accurate computational protocol using simplified explicit correlation terms. Its performance is illustrated on a number of weakly bound complexes, including water dimer, benzene/hydrogen, T-shape benzene dimer and stacked adenine-thymine DNA base pair complex. The proposed protocol achieves excellent agreement ($\\sim$0.2 kcal/mol) with respect to the reli...

  20. [Analysis on the accuracy of simple selection method of Fengshi (GB 31)].

    Science.gov (United States)

    Li, Zhixing; Zhang, Haihua; Li, Suhe

    2015-12-01

    To explore the accuracy of simple selection method of Fengshi (GB 31). Through the study of the ancient and modern data,the analysis and integration of the acupuncture books,the comparison of the locations of Fengshi (GB 31) by doctors from all dynasties and the integration of modern anatomia, the modern simple selection method of Fengshi (GB 31) is definite, which is the same as the traditional way. It is believed that the simple selec tion method is in accord with the human-oriented thought of TCM. Treatment by acupoints should be based on the emerging nature and the individual difference of patients. Also, it is proposed that Fengshi (GB 31) should be located through the integration between the simple method and body surface anatomical mark.

  1. Combining data fusion with multiresolution analysis for improving the classification accuracy of uterine EMG signals

    Science.gov (United States)

    Moslem, Bassam; Diab, Mohamad; Khalil, Mohamad; Marque, Catherine

    2012-12-01

    Multisensor data fusion is a powerful solution for solving difficult pattern recognition problems such as the classification of bioelectrical signals. It is the process of combining information from different sensors to provide a more stable and more robust classification decisions. We combine here data fusion with multiresolution analysis based on the wavelet packet transform (WPT) in order to classify real uterine electromyogram (EMG) signals recorded by 16 electrodes. Herein, the data fusion is done at the decision level by using a weighted majority voting (WMV) rule. On the other hand, the WPT is used to achieve significant enhancement in the classification performance of each channel by improving the discrimination power of the selected feature. We show that the proposed approach tested on our recorded data can improve the recognition accuracy in labor prediction and has a competitive and promising performance.

  2. Accuracy analysis on Rayleigh lidar measurements of atmospheric temperature based on spectroscopy

    Institute of Scientific and Technical Information of China (English)

    Kun Liang; Yong Ma; Fei Cheng; Hongyuan Wang

    2009-01-01

    We make a detailed analysis on the linearity and accuracy of the relationship between the full-width at half-height (FWHH) of the atmosphere molecules Rayleigh scattering spectrum and the square root of the atmospheric temperature. A simulation of the FWHH of the atmosphere molecules Rayleigh scattering spectrum is made based on the S6 Atmosphere Model and U.S. Standard Atmosphere Model. The calcu-lated temperature is compared with the initial simulation temperature. The result shows that the FWHH of the atmosphere molecules Rayleigh scattering spectrum is nearly proportional to the atmospheric tem-perature. The goodness-of-fit index of the fitting curve is 0.9977 and the maximum absolute error of measured atmospheric temperature is about 2 K.

  3. Subpixel Accuracy Analysis of Phase Correlation Shift Measurement Methods Applied to Satellite Imagery

    Directory of Open Access Journals (Sweden)

    S.M. Badwai

    2013-01-01

    Full Text Available the key point of super resolution process is the accurate measuring of sub-pixel shift. Any tiny error in measuring such shift leads to an incorrect image focusing. In this paper, methodology of measuring sub-pixel shift using Phase correlation (PC are evaluated using different window functions, then modified version of (PC method using high pass filter (HPF is introduced . Comprehensive analysis and assessment of (PC methods shows that different natural features yield different shift measurements. It is concluded that there is no universal window function for measuring shift; it mainly depends on the features in the satellite images. Even the question of which window is optimal of particular feature is generally remains open. This paper presents the design of a method for obtaining high accuracy sub pixel shift phase correlation using (HPF.The proposed method makes the change in the different locations that lack of edges easy.

  4. On the accuracy of protein determination in large biological samples by prompt gamma neutron activation analysis

    International Nuclear Information System (INIS)

    A prompt gamma neutron activation analysis (PGNAA) facility has been developed for the determination of nitrogen and thus total protein in large volume biological samples or the whole body of small animals. In the present work, the accuracy of nitrogen determination by PGNAA in phantoms of known composition as well as in four raw ground meat samples of about 1 kg mass was examined. Dumas combustion and Kjeldahl techniques were also used for the assessment of nitrogen concentration in the meat samples. No statistically significant differences were found between the concentrations assessed by the three techniques. The results of this work demonstrate the applicability of PGNAA for the assessment of total protein in biological samples of 0.25-1.5 kg mass, such as a meat sample or the body of small animal even in vivo with an equivalent radiation dose of about 40 mSv

  5. Comprehensive Numerical Analysis of Finite Difference Time Domain Methods for Improving Optical Waveguide Sensor Accuracy

    Directory of Open Access Journals (Sweden)

    M. Mosleh E. Abu Samak

    2016-04-01

    Full Text Available This paper discusses numerical analysis methods for different geometrical features that have limited interval values for typically used sensor wavelengths. Compared with existing Finite Difference Time Domain (FDTD methods, the alternating direction implicit (ADI-FDTD method reduces the number of sub-steps by a factor of two to three, which represents a 33% time savings in each single run. The local one-dimensional (LOD-FDTD method has similar numerical equation properties, which should be calculated as in the previous method. Generally, a small number of arithmetic processes, which result in a shorter simulation time, are desired. The alternating direction implicit technique can be considered a significant step forward for improving the efficiency of unconditionally stable FDTD schemes. This comparative study shows that the local one-dimensional method had minimum relative error ranges of less than 40% for analytical frequencies above 42.85 GHz, and the same accuracy was generated by both methods.

  6. Diagnostic Accuracy of MALDI Mass Spectrometric Analysis of Unfractionated Serum in Lung Cancer

    Science.gov (United States)

    Yildiz, Pinar B.; Shyr, Yu; Rahman, Jamshedur S. M.; Wardwell, Noel R.; Zimmerman, Lisa J.; Shakhtour, Bashar; Gray, William H.; Chen, Shuo; Li, Ming; Roder, Heinrich; Liebler, Daniel C.; Bigbee, William L.; Siegfried, Jill M.; Weissfeld, Joel L.; Gonzalez, Adriana L.; Ninan, Mathew; Johnson, David H.; Carbone, David P.; Caprioli, Richard M.; Massion, Pierre P.

    2014-01-01

    Purpose There is a critical need for improvements in the noninvasive diagnosis of lung cancer. We hypothesized that matrix-assisted laser desorption ionization mass spectrometry (MALDI MS) analysis of the most abundant peptides in the serum may distinguish lung cancer cases from matched controls. Patients and Methods We used MALDI MS to analyze unfractionated serum from a total of 288 cases and matched controls split into training (n = 182) and test sets (n = 106). We used a training–testing paradigm with application of the model profile defined in a training set to a blinded test cohort. Results Reproducibility and lack of analytical bias was confirmed in quality-control studies. A serum proteomic signature of seven features in the training set reached an overall accuracy of 78%, a sensitivity of 67.4%, and a specificity of 88.9%. In the blinded test set, this signature reached an overall accuracy of 72.6 %, a sensitivity of 58%, and a specificity of 85.7%. The serum signature was associated with the diagnosis of lung cancer independently of gender, smoking status, smoking pack-years, and C-reactive protein levels. From this signature, we identified three discriminatory features as members of a cluster of truncated forms of serum amyloid A. Conclusions We found a serum proteomic profile that discriminates lung cancer from matched controls. Proteomic analysis of unfractionated serum may have a role in the noninvasive diagnosis of lung cancer and will require methodological refinements and prospective validation to achieve clinical utility. PMID:17909350

  7. Diagnostic accuracy of real-time tissue elastography for breast cancer:a meta-analysis

    Institute of Scientific and Technical Information of China (English)

    Cong Wang; Guang Yang; Hui Wang

    2016-01-01

    Objective The present study aimed to determine the accuracy of real-time tissue elastography (RTE) for the diagnosis of breast cancer. Methods The search was conducted in the PubMed, Web of Science, Cochrane Library, and China Biology Medicine databases from inception through December 31, 2014, without language restrictions. The meta-analysis was conducted using STATA version 12.0 and Meta-Disc version 1.4. We calculated the summary statistics for sensitivity (Sen), specificity (Spe), positive and negative likelihood ratio (LR+/LR–), diagnostic odds ratio (DOR), and summary receiver operating characteristic (SROC) curve. Results Ten studies that met al inclusion criteria were included in the meta-analysis. A total of 608 ma-lignant breast lesions and 1292 benign breast tumors were assessed. Al breast lesions were histological y confirmed after RTE. The pooled Sen was 0.83 (95% CI = 0.79–0.86); the pooled Spe was 0.86 (95% CI = 0.84–0.88). The pooled LR+ was 9.87 (95% CI = 2.66–36.71); the pooled LR– was 0.20 (95% CI = 0.17–0.23). The pooled DOR of RTE for the diagnosis of breast cancer was 62.21 (95% CI = 33.88–114.24). The area under the SROC curve was 0.9334 (standard error = 0.00125). We found no evidence of publica-tion bias (t = –0.57, P = 0.582). Conclusion RTE may have high diagnostic accuracy for the dif erential diagnosis of benign and malig-nant breast tumors. RTE may be a good tool for breast cancer diagnosis.

  8. Implementation of the European multicentre database of healthy controls for [{sup 123}I]FP-CIT SPECT increases diagnostic accuracy in patients with clinically uncertain parkinsonian syndromes

    Energy Technology Data Exchange (ETDEWEB)

    Albert, Nathalie L.; Unterrainer, Marcus; Xiong, Guoming; Bartenstein, Peter; Koch, Walter [University of Munich, Department of Nuclear Medicine, Munich (Germany); Diemling, Markus [Hermes Medical Solutions, Stockholm (Sweden); Varrone, Andrea [Karolinska University Hospital, Karolinska Institutet, Department of Clinical Neuroscience, Centre for Psychiatry Research, Stockholm (Sweden); Dickson, John C. [UCLH NHS Foundation Trust and University College, Institute of Nuclear Medicine, London (United Kingdom); Tossici-Bolt, Livia [University Hospitals Southampton NHS Trust, Department of Medical Physics, Southampton (United Kingdom); Sera, Terez [University of Szeged, Department of Nuclear Medicine and Euromedic Szeged, Szeged (Hungary); Asenbaum, Susanne [Medical University of Vienna, Department of Neurology, Vienna (Austria); Booij, Jan [University of Amsterdam, Department of Nuclear Medicine, Academic Medical Centre, Amsterdam (Netherlands); Kapucu, L. Oezlem A. [Gazi University, Department of Nuclear Medicine, Faculty of Medicine, Ankara (Turkey); Kluge, Andreas [ABX-CRO, Dresden (Germany); Ziebell, Morten [Rigshospitalet and University of Copenhagen, Neurobiology Research Unit, Copenhagen (Denmark); Darcourt, Jacques [University of Nice-Sophia Antipolis, Nuclear Medicine Department, Centre Antoine Lacassagne, Nice (France); Nobili, Flavio [University of Genoa, Clinical Neurology Unit, Department of Neuroscience (DINOGMI), Genoa (Italy); Pagani, Marco [Institute of Cognitive Sciences and Technologies, CNR, Rome (Italy); Karolinska Hospital, Department of Nuclear medicine, Stockholm (Sweden); Sabri, Osama [University of Leipzig, Department of Nuclear Medicine, Leipzig (Germany); Hesse, Swen [University of Leipzig, Department of Nuclear Medicine, Leipzig (Germany); Leipzig University Medical Centre, Molecular Neuroimaging IFB Adiposity Diseases, Leipzig (Germany); Borght, Thierry vander [Universite Catholique de Louvain, Nuclear Medicine Division, Mont-Godinne Medical Center, Yvoir (Belgium); Laere, Koen van [University Hospital and K.U. Leuven, Nuclear Medicine, Leuven (Belgium); Tatsch, Klaus [Staedtisches Klinikum Karlsruhe, Department of Nuclear Medicine, Karlsruhe (Germany); La Fougere, Christian [University of Tuebingen, Division of Nuclear Medicine, Department of Radiology, Tuebingen (Germany)

    2016-07-15

    Even though [{sup 123}I]FP-CIT SPECT provides high accuracy in detecting nigrostriatal cell loss in neurodegenerative parkinsonian syndromes (PS), some patients with an inconclusive diagnosis remain. We investigated whether the diagnostic accuracy in patients with clinically uncertain PS with previously inconclusive findings can be improved by the use of iterative reconstruction algorithms and an improved semiquantitative evaluation which additionally implemented a correction algorithm for patient age and gamma camera dependency (EARL-BRASS; Hermes Medical Solutions, Sweden). We identified 101 patients with inconclusive findings who underwent an [{sup 123}I]FP-CIT SPECT between 2003 and 2010 as part of the diagnostic process of suspected PS at the University of Munich, and re-evaluated these scans using iterative reconstruction algorithms and the new corrected EARL-BRASS. Clinical follow-up was obtained in 62 out of the 101 patients and constituted the gold standard for the re-evaluation to assess the possible improvement in diagnostic accuracy. Clinical follow-up confirmed the diagnosis of PS in 11 of the 62 patients. In patients in whom both visual and semiquantitative analysis showed concordant findings (48 patients), a high negative predictive value (93 %), positive predictive value (100 %) and accuracy (94 %) were found, and thus a correct diagnosis was obtained in 45 of the 48 patients. Among the 14 patients with discordant findings, the additional semiquantitative analysis correctly identified all five of nine patients patients without PS by nonpathological semiquantitative findings in visually pathological or inconclusive scans. In contrast, four of the remaining five patients with decreased semiquantitative values but visually normal scans did not show a PS during follow-up. The age-corrected and camera-corrected mode of evaluation using EARL-BRASS provided a notable improvement in the diagnostic accuracy of [{sup 123}I]FP-CIT SPECT in PS patients with

  9. Implementation of the European multicentre database of healthy controls for [123I]FP-CIT SPECT increases diagnostic accuracy in patients with clinically uncertain parkinsonian syndromes

    International Nuclear Information System (INIS)

    Even though [123I]FP-CIT SPECT provides high accuracy in detecting nigrostriatal cell loss in neurodegenerative parkinsonian syndromes (PS), some patients with an inconclusive diagnosis remain. We investigated whether the diagnostic accuracy in patients with clinically uncertain PS with previously inconclusive findings can be improved by the use of iterative reconstruction algorithms and an improved semiquantitative evaluation which additionally implemented a correction algorithm for patient age and gamma camera dependency (EARL-BRASS; Hermes Medical Solutions, Sweden). We identified 101 patients with inconclusive findings who underwent an [123I]FP-CIT SPECT between 2003 and 2010 as part of the diagnostic process of suspected PS at the University of Munich, and re-evaluated these scans using iterative reconstruction algorithms and the new corrected EARL-BRASS. Clinical follow-up was obtained in 62 out of the 101 patients and constituted the gold standard for the re-evaluation to assess the possible improvement in diagnostic accuracy. Clinical follow-up confirmed the diagnosis of PS in 11 of the 62 patients. In patients in whom both visual and semiquantitative analysis showed concordant findings (48 patients), a high negative predictive value (93 %), positive predictive value (100 %) and accuracy (94 %) were found, and thus a correct diagnosis was obtained in 45 of the 48 patients. Among the 14 patients with discordant findings, the additional semiquantitative analysis correctly identified all five of nine patients patients without PS by nonpathological semiquantitative findings in visually pathological or inconclusive scans. In contrast, four of the remaining five patients with decreased semiquantitative values but visually normal scans did not show a PS during follow-up. The age-corrected and camera-corrected mode of evaluation using EARL-BRASS provided a notable improvement in the diagnostic accuracy of [123I]FP-CIT SPECT in PS patients with previously

  10. INCREASING ACCURACY VALUE IN THE ESTIMATES OF CARBON STOCK BY USING VEGETATION INDEX FROM ALOS AVNIR 2 SATELLITE IMAGERY

    Directory of Open Access Journals (Sweden)

    Irland Fardani

    2016-04-01

    Full Text Available The existence of carbon stock began to be noticed by the public, especially after the global warming phenomenon, because one of the causes of global warming is the increasing amount of carbon in the atmosphere. There are several approaches that can be used to calculate carbon stocks, one of which is through remote sensing. In the study of carbon stocks in Meru Betiri National Park Indonesia, the vegetation index from ALOS-AVNIR satellite imagery is used to estimate carbon reserves by finding an exact equation. If it uses the Modified Soil Adjusted Vegetation Index (MSAVI only, the correlation value is 0.49. Meanwhile, if Infrared Percentage Vegetation Index (IPVI is used, the correlation value is 0.47. However, if some vegetation indices such as Soil-Adjusted Vegetation Index (SAVI, Normalize Difference Vegetation Index (NDVI and Ratio Vegetation Index (RVI are combined, the correlation value of the equation is 0.63. The comparison showed that by combining several variables of vegetation indices will increase the value of the correlation equation significantly.

  11. Accuracy of chemical analysis of airborne particulates: results of an intercomparison exercise

    International Nuclear Information System (INIS)

    Since suitable standard reference materials for chemical analysis of airborne particulates are not available, an intercomparison exercise was carried out among 40 interested laboratories in order to evaluate the accuracy of various trace analysis techniques for this specific application. Six hundred grams of airborne particulates were collected from the inlet filters of the air conditioning installation of a hotel in the center of Milan. The sample was sieved to remove coarser particles, thoroughly mixed, and distributed in 1 to 5 gram aliquots. The homogeneity was checked by relative measurements carried out by three independent techniques. For 40 elements no inhomogeneity was found to exceed the analytical error, which was estimated to be approximately 10 percent. The data of the analytical exercise are being collected and evaluated. Results are available for 56 elements, but to date only 33 have been determined by more than one technique. Activation analysis, emission spectroscopy, atomic absorption, x-ray fluorescence and various wet chemical methods contributed to the intercomparison. No result was received from mass spectroscopic methods and, although analyses were specifically encouraged, very few results were received on the organic components. From a first approximate evaluation a good agreement was found for Al, Fe, Zn, Mn, Ca, Pb, Cl, S, Si, Ti, Mn, while for the other elements no definite conclusion can yet be drawn. An attempt will be made to interpret important cases of systematic errors, a few of which are already evident

  12. Analysis of Increased Information Technology Outsourcing Factors

    Directory of Open Access Journals (Sweden)

    Brcar Franc

    2013-01-01

    Full Text Available The study explores the field of IT outsourcing. The narrow field of research is to build a model of IT outsourcing based on influential factors. The purpose of this research is to determine the influential factors on IT outsourcing expansion. A survey was conducted with 141 large-sized Slovenian companies. Data were statistically analyzed using binary logistic regression. The final model contains five factors: (1 management’s support; (2 knowledge on IT outsourcing; (3 improvement of efficiency and effectiveness; (4 quality improvement of IT services; and (5 innovation improvement of IT. Managers immediately can use the results of this research in their decision-making. Increased performance of each individual organization is to the benefit of the entire society. The examination of IT outsourcing with the methods used is the first such research in Slovenia.

  13. Confusion assessment method: a systematic review and meta-analysis of diagnostic accuracy

    Directory of Open Access Journals (Sweden)

    Shi Q

    2013-09-01

    Full Text Available Qiyun Shi,1,2 Laura Warren,3 Gustavo Saposnik,2 Joy C MacDermid1 1Health and Rehabilitation Sciences, Western University, London, Ontario, Canada; 2Stroke Outcomes Research Center, Department of Medicine, St Michael's Hospital, University of Toronto, Toronto, Ontario, Canada; 3Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada Background: Delirium is common in the early stages of hospitalization for a variety of acute and chronic diseases. Objectives: To evaluate the diagnostic accuracy of two delirium screening tools, the Confusion Assessment Method (CAM and the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU. Methods: We searched MEDLINE, EMBASE, and PsychInfo for relevant articles published in English up to March 2013. We compared two screening tools to Diagnostic and Statistical Manual of Mental Disorders IV criteria. Two reviewers independently assessed studies to determine their eligibility, validity, and quality. Sensitivity and specificity were calculated using a bivariate model. Results: Twenty-two studies (n = 2,442 patients met the inclusion criteria. All studies demonstrated that these two scales can be administered within ten minutes, by trained clinical or research staff. The pooled sensitivities and specificity for CAM were 82% (95% confidence interval [CI]: 69%–91% and 99% (95% CI: 87%–100%, and 81% (95% CI: 57%–93% and 98% (95% CI: 86%–100% for CAM-ICU, respectively. Conclusion: Both CAM and CAM-ICU are validated instruments for the diagnosis of delirium in a variety of medical settings. However, CAM and CAM-ICU both present higher specificity than sensitivity. Therefore, the use of these tools should not replace clinical judgment. Keywords: confusion assessment method, diagnostic accuracy, delirium, systematic review, meta-analysis

  14. Evaluation of the accuracy of analysis tools for atmospheric new particle formation

    Directory of Open Access Journals (Sweden)

    H. Korhonen

    2011-04-01

    Full Text Available Several mathematical tools have been developed in recent years to analyze new particle formation rates and to estimate nucleation rates and mechanisms at sub-3 nm sizes from atmospheric aerosol data. Here we evaluate these analysis tools using 1239 numerical nucleation events for which the nucleation mechanism and formation rates were known exactly. The accuracy of the estimates of particle formation rate at 3 nm (J3 showed significant sensitivity to the details of the analysis, i.e. form of equations used and assumptions made about the initial size of nucleating clusters, with the fraction of events within a factor-of-two accuracy ranging from 43–97%. In general, the estimates of the actual nucleation rate at 1.5 nm (J1.5 were less accurate, and even the most accurate analysis set-up estimated only 59% of the events within a factor of two of the simulated mean nucleation rate. The J1.5 estimates were deteriorated mainly by the size dependence of the cluster growth rate below 3 nm, which the analysis tools do not take into account, but also by possible erroneous assumptions about the initial cluster size. The poor estimates of J1.5 can lead to large uncertainties in the nucleation prefactors (i.e. constant P in nucleation equation J1.5 = P × [H2SO4]k. Large uncertainties were found also in the procedures that are used to determine the nucleation mechanism. When applied to individual events, the analysis tools clearly overestimated the number of H2SO4 molecules in a critical cluster for most events, and thus associated them with a wrong nucleation mechanism. However, in some conditions the number of H2SO4 molecules in a critical cluster was underestimated. This indicates that analysis of field data that implies a maximum of 2 H2SO4 molecules in

  15. Image Positioning Accuracy Analysis for the Super Low Altitude Remote Sensing Satellite

    Directory of Open Access Journals (Sweden)

    Ming Xu

    2012-10-01

    Full Text Available Super low altitude remote sensing satellites maintain lower flight altitudes by means of ion propulsion in order to improve image resolution and positioning accuracy. The use of engineering data in design for achieving image positioning accuracy is discussed in this paper based on the principles of the photogrammetry theory. The exact line‐of‐sight rebuilding of each detection element and this direction precisely intersecting with the Earth’s elliptical when the camera on the satellite is imaging are both ensured by the combined design of key parameters. These parameters include: orbit determination accuracy, attitude determination accuracy, camera exposure time, accurately synchronizing the reception of ephemeris with attitude data, geometric calibration and precise orbit verification. Precise simulation calculations show that image positioning accuracy of super low altitude remote sensing satellites is not obviously improved. The attitude determination error of a satellite still restricts its positioning accuracy.

  16. Reliability and accuracy of a radiographic analysis method for posterior maxillary mini-implant location

    Directory of Open Access Journals (Sweden)

    Luís Carlos Sampaio Dias

    2012-02-01

    Full Text Available OBJECTIVE: The purpose of this study was to evaluate the reliability and accuracy of a radiographic analysis method for the location of mini-implants inserted in the posterior region of the maxilla. MATERIAL AND METHODS: Two self-drilling mini-implants were installed between the second premolar and the first molar on the right side and left side in three dry skulls. Three operators performed three occlusal radiographs, using an occlusal x-ray film holder, at three different times in each of the three skulls. RESULTS: The interclass correlation coefficient showed a significantly high, positive correlation (p<0.05, indicating an excellent reliability between operators. The analysis of variance showed no significant differences in time and among the operators. CONCLUSION: Based of these findings, it may be concluded that this methodology can be used by several operators in longitudinal clinical studies on orthodontic mini-implants at the anterior-posterior and lateral-medial locations or longitudinal displacement.

  17. Evaluation of the accuracy of analysis tools for atmospheric new particle formation

    Directory of Open Access Journals (Sweden)

    H. Korhonen

    2010-11-01

    Full Text Available Several mathematical tools have been developed in recent years to analyze new particle formation rates and to estimate nucleation rates and mechanisms at sub-3nm sizes from atmospheric aerosol data. Here we evaluate these analysis tools using 1239 numerical nucleation events for which the nucleation mechanism and formation rates were known exactly. The accuracy of the estimates of particle formation rate at 3 nm (J3 showed significant sensitivity to the details of the analysis, i.e. form of equations used and assumptions made about the initial size of nucleating clusters, with the fraction of events within a factor-of-two accuracy ranging from 43–97%. In general, the estimates of the actual nucleation rate at 1.5 nm (J1.5 were less accurate, and even the most accurate analysis set-up estimated only 59% of the events within a factor of two of the simulated mean nucleation rate. The J1.5 estimates were deteriorated mainly by the size dependence of the cluster growth rate below 3 nm, which the analysis tools do not take into account, but also by possible erroneous assumptions about the initial cluster size. The poor estimates of J1.5 can lead to large uncertainties in the nucleation prefactors (i.e. constant P in nucleation equation J1.5 = P × [H2SO4]k. Large uncertainties were found also in the procedures that are used to determine the nucleation mechanism. When applied to individual events, the analysis tools clearly overestimated the number of H2SO4 molecules in a critical cluster for most events, and thus associated them with a wrong nucleation mechanism. However, in some conditions the number of H2SO4 molecules in a critical cluster was underestimated. This indicates that analysis of field data that implies a maximum of 2 H2SO4 molecules in

  18. Systematic review and meta-analysis of the diagnostic accuracy of ultrasonography for deep vein thrombosis

    Directory of Open Access Journals (Sweden)

    van Beek Edwin

    2005-10-01

    Full Text Available Abstract Background Ultrasound (US has largely replaced contrast venography as the definitive diagnostic test for deep vein thrombosis (DVT. We aimed to derive a definitive estimate of the diagnostic accuracy of US for clinically suspected DVT and identify study-level factors that might predict accuracy. Methods We undertook a systematic review, meta-analysis and meta-regression of diagnostic cohort studies that compared US to contrast venography in patients with suspected DVT. We searched Medline, EMBASE, CINAHL, Web of Science, Cochrane Database of Systematic Reviews, Cochrane Controlled Trials Register, Database of Reviews of Effectiveness, the ACP Journal Club, and citation lists (1966 to April 2004. Random effects meta-analysis was used to derive pooled estimates of sensitivity and specificity. Random effects meta-regression was used to identify study-level covariates that predicted diagnostic performance. Results We identified 100 cohorts comparing US to venography in patients with suspected DVT. Overall sensitivity for proximal DVT (95% confidence interval was 94.2% (93.2 to 95.0, for distal DVT was 63.5% (59.8 to 67.0, and specificity was 93.8% (93.1 to 94.4. Duplex US had pooled sensitivity of 96.5% (95.1 to 97.6 for proximal DVT, 71.2% (64.6 to 77.2 for distal DVT and specificity of 94.0% (92.8 to 95.1. Triplex US had pooled sensitivity of 96.4% (94.4 to 97.1% for proximal DVT, 75.2% (67.7 to 81.6 for distal DVT and specificity of 94.3% (92.5 to 95.8. Compression US alone had pooled sensitivity of 93.8 % (92.0 to 95.3% for proximal DVT, 56.8% (49.0 to 66.4 for distal DVT and specificity of 97.8% (97.0 to 98.4. Sensitivity was higher in more recently published studies and in cohorts with higher prevalence of DVT and more proximal DVT, and was lower in cohorts that reported interpretation by a radiologist. Specificity was higher in cohorts that excluded patients with previous DVT. No studies were identified that compared repeat US to

  19. Systematic review and meta-analysis of the diagnostic accuracy of ultrasonography for deep vein thrombosis

    International Nuclear Information System (INIS)

    Ultrasound (US) has largely replaced contrast venography as the definitive diagnostic test for deep vein thrombosis (DVT). We aimed to derive a definitive estimate of the diagnostic accuracy of US for clinically suspected DVT and identify study-level factors that might predict accuracy. We undertook a systematic review, meta-analysis and meta-regression of diagnostic cohort studies that compared US to contrast venography in patients with suspected DVT. We searched Medline, EMBASE, CINAHL, Web of Science, Cochrane Database of Systematic Reviews, Cochrane Controlled Trials Register, Database of Reviews of Effectiveness, the ACP Journal Club, and citation lists (1966 to April 2004). Random effects meta-analysis was used to derive pooled estimates of sensitivity and specificity. Random effects meta-regression was used to identify study-level covariates that predicted diagnostic performance. We identified 100 cohorts comparing US to venography in patients with suspected DVT. Overall sensitivity for proximal DVT (95% confidence interval) was 94.2% (93.2 to 95.0), for distal DVT was 63.5% (59.8 to 67.0), and specificity was 93.8% (93.1 to 94.4). Duplex US had pooled sensitivity of 96.5% (95.1 to 97.6) for proximal DVT, 71.2% (64.6 to 77.2) for distal DVT and specificity of 94.0% (92.8 to 95.1). Triplex US had pooled sensitivity of 96.4% (94.4 to 97.1%) for proximal DVT, 75.2% (67.7 to 81.6) for distal DVT and specificity of 94.3% (92.5 to 95.8). Compression US alone had pooled sensitivity of 93.8 % (92.0 to 95.3%) for proximal DVT, 56.8% (49.0 to 66.4) for distal DVT and specificity of 97.8% (97.0 to 98.4). Sensitivity was higher in more recently published studies and in cohorts with higher prevalence of DVT and more proximal DVT, and was lower in cohorts that reported interpretation by a radiologist. Specificity was higher in cohorts that excluded patients with previous DVT. No studies were identified that compared repeat US to venography in all patients. Repeat US

  20. Evaluation of factors affecting the accuracy of impressions using quantitative surface analysis.

    Science.gov (United States)

    Lee, I K; DeLong, R; Pintado, M R; Malik, R

    1995-01-01

    Impression material goes from a plastic to an elastic state during setting. Movement of the impression and excessive seating pressure during this transition can cause distortion in the impressions. The purpose of this study is to determine if the impression distortion is related to movement during setting or to distortion of the putty phase in the two-step impressioning technique. A master model of a maxillary quadrant of teeth was impressed using four different procedures: 1) one-step technique without movement (1S-NM); 2) one-step technique with movement (1S-M); 3) two-step technique without movement (2S-NM); and 4) two-step technique with movement (2S-M). An artificial oral environment and surface analysis technique of the Minnesota Dental Research Center for Biomaterials and Biomechanics were used to produce the impressions and measure their accuracy. A digitized image of the first premolar of the master model was aligned with a digitized image of the first premolar of each epoxy model using AnSur. The root mean squared difference (RMS) between the aligned images is a measure of the distortion. The corresponding RMS values for the different methods were: 1S-NM = 23.7 +/- 9.21; 1S-M = 20.4 +/- 3.9; 2S-NM = 20.5 +/- 7.7; 2S-M = 21.3 +/- 4.4. Statistical analysis using a two-way analysis of variance showed no difference at the 0.05 level of significance. Pairwise comparison using the Tukey method showed that neither technique (one-step vs two-step) nor movement is a significant factor. These results showed that low seating pressure will not cause any greater distortions in the two-step impression technique than in the one-step technique, and minor movement during the setting of the impression material will no cause distortion.

  1. The analysis accuracy assessment of CORINE land cover in the Iberian coast

    OpenAIRE

    Romano Grullón, Ramona Yraida; Alhaddad, Bahaa Eddin; Roca Cladera, Josep

    2009-01-01

    OBJECTIVES: 1. Evaluate databases accuracy of Corine land cover; 2. Present methods to test map error which help to explain the observed differences between various categories of land covers; 3. Explain the observed differences between various data sources in different scale levels; 4. Calculate the accuracy assessments. Peer Reviewed

  2. Accuracy analysis of direct georeferenced UAV images utilising low-cost navigation sensors

    Science.gov (United States)

    Briese, Christian; Wieser, Martin; Verhoeven, Geert; Glira, Philipp; Doneus, Michael; Pfeifer, Norbert

    2014-05-01

    control points should be used to improve the estimated values, especially to decrease the amount of systematic errors. For the bundle block adjustment the calibration of the camera and their temporal stability must be determined additionally. This contribution presents next to the theory a practical study on the accuracy analysis of direct georeferenced UAV imagery by low-cost navigation sensors. The analysis was carried out within the research project ARAP (automated (ortho)rectification of archaeological aerial photographs). The utilized UAS consists of the airplane "MAJA", manufactured by "Bormatec" (length: 1.2 m, wingspan: 2.2 m) equipped with the autopilot "ArduPilot Mega 2.5". For image acquisition the camera "Ricoh GR Digital IV" is utilised. The autopilot includes a GNSS receiver capable of DGPS (EGNOS), an inertial measurement system (INS), a barometer, and a magnetometer. In the study the achieved accuracies for the estimated position and orientation of the images are presented. The paper concludes with a summary of the remaining error sources and their possible corrections by applying further improvements on the utilised equipment and the direct georeferencing process.

  3. Analysis of Scattering Components from Fully Polarimetric SAR Images for Improving Accuracies of Urban Density Estimation

    Science.gov (United States)

    Susaki, J.

    2016-06-01

    In this paper, we analyze probability density functions (PDFs) of scatterings derived from fully polarimetric synthetic aperture radar (SAR) images for improving the accuracies of estimated urban density. We have reported a method for estimating urban density that uses an index Tv+c obtained by normalizing the sum of volume and helix scatterings Pv+c. Validation results showed that estimated urban densities have a high correlation with building-to-land ratios (Kajimoto and Susaki, 2013b; Susaki et al., 2014). While the method is found to be effective for estimating urban density, it is not clear why Tv+c is more effective than indices derived from other scatterings, such as surface or double-bounce scatterings, observed in urban areas. In this research, we focus on PDFs of scatterings derived from fully polarimetric SAR images in terms of scattering normalization. First, we introduce a theoretical PDF that assumes that image pixels have scatterers showing random backscattering. We then generate PDFs of scatterings derived from observations of concrete blocks with different orientation angles, and from a satellite-based fully polarimetric SAR image. The analysis of the PDFs and the derived statistics reveals that the curves of the PDFs of Pv+c are the most similar to the normal distribution among all the scatterings derived from fully polarimetric SAR images. It was found that Tv+c works most effectively because of its similarity to the normal distribution.

  4. High Accuracy Passive Magnetic Field-Based Localization for Feedback Control Using Principal Component Analysis.

    Science.gov (United States)

    Foong, Shaohui; Sun, Zhenglong

    2016-01-01

    In this paper, a novel magnetic field-based sensing system employing statistically optimized concurrent multiple sensor outputs for precise field-position association and localization is presented. This method capitalizes on the independence between simultaneous spatial field measurements at multiple locations to induce unique correspondences between field and position. This single-source-multi-sensor configuration is able to achieve accurate and precise localization and tracking of translational motion without contact over large travel distances for feedback control. Principal component analysis (PCA) is used as a pseudo-linear filter to optimally reduce the dimensions of the multi-sensor output space for computationally efficient field-position mapping with artificial neural networks (ANNs). Numerical simulations are employed to investigate the effects of geometric parameters and Gaussian noise corruption on PCA assisted ANN mapping performance. Using a 9-sensor network, the sensing accuracy and closed-loop tracking performance of the proposed optimal field-based sensing system is experimentally evaluated on a linear actuator with a significantly more expensive optical encoder as a comparison. PMID:27529253

  5. High Accuracy Passive Magnetic Field-Based Localization for Feedback Control Using Principal Component Analysis

    Directory of Open Access Journals (Sweden)

    Shaohui Foong

    2016-08-01

    Full Text Available In this paper, a novel magnetic field-based sensing system employing statistically optimized concurrent multiple sensor outputs for precise field-position association and localization is presented. This method capitalizes on the independence between simultaneous spatial field measurements at multiple locations to induce unique correspondences between field and position. This single-source-multi-sensor configuration is able to achieve accurate and precise localization and tracking of translational motion without contact over large travel distances for feedback control. Principal component analysis (PCA is used as a pseudo-linear filter to optimally reduce the dimensions of the multi-sensor output space for computationally efficient field-position mapping with artificial neural networks (ANNs. Numerical simulations are employed to investigate the effects of geometric parameters and Gaussian noise corruption on PCA assisted ANN mapping performance. Using a 9-sensor network, the sensing accuracy and closed-loop tracking performance of the proposed optimal field-based sensing system is experimentally evaluated on a linear actuator with a significantly more expensive optical encoder as a comparison.

  6. Positioning accuracy analysis of adjusting target mechanism of three-dimensional attitude

    International Nuclear Information System (INIS)

    A novel adjusting target mechanism of three-dimensional attitude is presented according to the characteristics of the target transport subsystem in inertial confinement fusion (ICF). The mechanism consists of a tangent mechanism adjusting rotation angle and a set of orthogonal tangent mechanism adjusting two-dimensional deflection angles. The structural parameters of the adjusting target mechanism are analyzed according to principle errors, structure errors and motion errors of following. The analysis results indicate that the system error of the adjusting target mechanism is influenced by the displacement of the linear actuators, the actuator ball radius, the working radius of the tangent mechanism, the angle error of the inclined installation hole, the centralization error of the actuators, the orthogonal error of the two tangent mechanism, and the angle errors of the inclined target rod inclined rotation shaft. The errors of the inclined target rod and inclined rotation shaft are the two greatest impact factors, the spherical contact error is the next. By means of precise assembly and control system compensation, the accuracy of the adjusting target mechanism can be less than 0.1 mrad. (authors)

  7. High Accuracy Passive Magnetic Field-Based Localization for Feedback Control Using Principal Component Analysis

    Science.gov (United States)

    Foong, Shaohui; Sun, Zhenglong

    2016-01-01

    In this paper, a novel magnetic field-based sensing system employing statistically optimized concurrent multiple sensor outputs for precise field-position association and localization is presented. This method capitalizes on the independence between simultaneous spatial field measurements at multiple locations to induce unique correspondences between field and position. This single-source-multi-sensor configuration is able to achieve accurate and precise localization and tracking of translational motion without contact over large travel distances for feedback control. Principal component analysis (PCA) is used as a pseudo-linear filter to optimally reduce the dimensions of the multi-sensor output space for computationally efficient field-position mapping with artificial neural networks (ANNs). Numerical simulations are employed to investigate the effects of geometric parameters and Gaussian noise corruption on PCA assisted ANN mapping performance. Using a 9-sensor network, the sensing accuracy and closed-loop tracking performance of the proposed optimal field-based sensing system is experimentally evaluated on a linear actuator with a significantly more expensive optical encoder as a comparison. PMID:27529253

  8. The psychology of intelligence analysis: drivers of prediction accuracy in world politics.

    Science.gov (United States)

    Mellers, Barbara; Stone, Eric; Atanasov, Pavel; Rohrbaugh, Nick; Metz, S Emlen; Ungar, Lyle; Bishop, Michael M; Horowitz, Michael; Merkle, Ed; Tetlock, Philip

    2015-03-01

    This article extends psychological methods and concepts into a domain that is as profoundly consequential as it is poorly understood: intelligence analysis. We report findings from a geopolitical forecasting tournament that assessed the accuracy of more than 150,000 forecasts of 743 participants on 199 events occurring over 2 years. Participants were above average in intelligence and political knowledge relative to the general population. Individual differences in performance emerged, and forecasting skills were surprisingly consistent over time. Key predictors were (a) dispositional variables of cognitive ability, political knowledge, and open-mindedness; (b) situational variables of training in probabilistic reasoning and participation in collaborative teams that shared information and discussed rationales (Mellers, Ungar, et al., 2014); and (c) behavioral variables of deliberation time and frequency of belief updating. We developed a profile of the best forecasters; they were better at inductive reasoning, pattern detection, cognitive flexibility, and open-mindedness. They had greater understanding of geopolitics, training in probabilistic reasoning, and opportunities to succeed in cognitively enriched team environments. Last but not least, they viewed forecasting as a skill that required deliberate practice, sustained effort, and constant monitoring of current affairs. PMID:25581088

  9. Accuracy and Uncertainty Analysis of PSBT Benchmark Exercises Using a Subchannel Code MATRA

    Directory of Open Access Journals (Sweden)

    Dae-Hyun Hwang

    2012-01-01

    Full Text Available In the framework of the OECD/NRC PSBT benchmark, the subchannel grade void distribution data and DNB data were assessed by a subchannel code, MATRA. The prediction accuracy and uncertainty of the zone-averaged void fraction at the central region of the 5 × 5 test bundle were evaluated for the steady-state and transient benchmark data. Optimum values of the turbulent mixing parameter were evaluated for the subchannel exit temperature distribution benchmark. The influence of the mixing vanes on the subchannel flow distribution was investigated through a CFD analysis. In addition, a regionwise turbulent mixing model was examined to account for the nonhomogeneous mixing characteristics caused by the vane effect. The steady-state DNB benchmark data with uniform and nonuniform axial power shapes were evaluated by employing various DNB prediction models: EPRI bundle CHF correlation, AECL-IPPE 1995 CHF lookup table, and representative mechanistic DNB models such as a sublayer dryout model and a bubble crowding model. The DNBR prediction uncertainties for various DNB models were evaluated from a Monte-Carlo simulation for a selected steady-state condition.

  10. High Accuracy Passive Magnetic Field-Based Localization for Feedback Control Using Principal Component Analysis.

    Science.gov (United States)

    Foong, Shaohui; Sun, Zhenglong

    2016-08-12

    In this paper, a novel magnetic field-based sensing system employing statistically optimized concurrent multiple sensor outputs for precise field-position association and localization is presented. This method capitalizes on the independence between simultaneous spatial field measurements at multiple locations to induce unique correspondences between field and position. This single-source-multi-sensor configuration is able to achieve accurate and precise localization and tracking of translational motion without contact over large travel distances for feedback control. Principal component analysis (PCA) is used as a pseudo-linear filter to optimally reduce the dimensions of the multi-sensor output space for computationally efficient field-position mapping with artificial neural networks (ANNs). Numerical simulations are employed to investigate the effects of geometric parameters and Gaussian noise corruption on PCA assisted ANN mapping performance. Using a 9-sensor network, the sensing accuracy and closed-loop tracking performance of the proposed optimal field-based sensing system is experimentally evaluated on a linear actuator with a significantly more expensive optical encoder as a comparison.

  11. Accuracy of ionospheric models used in GNSS and SBAS: methodology and analysis

    Science.gov (United States)

    Rovira-Garcia, A.; Juan, J. M.; Sanz, J.; González-Casado, G.; Ibáñez, D.

    2016-03-01

    The characterization of the accuracy of ionospheric models currently used in global navigation satellite systems (GNSSs) is a long-standing issue. The characterization remains a challenging problem owing to the lack of sufficiently accurate slant ionospheric determinations to be used as a reference. The present study proposes a methodology based on the comparison of the predictions of any ionospheric model with actual unambiguous carrier-phase measurements from a global distribution of permanent receivers. The differences are separated as hardware delays (a receiver constant plus a satellite constant) per day. The present study was conducted for the entire year of 2014, i.e. during the last solar cycle maximum. The ionospheric models assessed are the operational models broadcast by the global positioning system (GPS) and Galileo constellations, the satellite-based augmentation system (SBAS) (i.e. European Geostationary Navigation Overlay System (EGNOS) and wide area augmentation system (WAAS)), a number of post-process global ionospheric maps (GIMs) from different International GNSS Service (IGS) analysis centres (ACs) and, finally, a more sophisticated GIM computed by the research group of Astronomy and GEomatics (gAGE). Ionospheric models based on GNSS data and represented on a grid (IGS GIMs or SBAS) correct about 85 % of the total slant ionospheric delay, whereas the models broadcasted in the navigation messages of GPS and Galileo only account for about 70 %. Our gAGE GIM is shown to correct 95 % of the delay. The proposed methodology appears to be a useful tool to improve current ionospheric models.

  12. An Original Stepwise Multilevel Logistic Regression Analysis of Discriminatory Accuracy: The Case of Neighbourhoods and Health.

    Directory of Open Access Journals (Sweden)

    Juan Merlo

    Full Text Available Many multilevel logistic regression analyses of "neighbourhood and health" focus on interpreting measures of associations (e.g., odds ratio, OR. In contrast, multilevel analysis of variance is rarely considered. We propose an original stepwise analytical approach that distinguishes between "specific" (measures of association and "general" (measures of variance contextual effects. Performing two empirical examples we illustrate the methodology, interpret the results and discuss the implications of this kind of analysis in public health.We analyse 43,291 individuals residing in 218 neighbourhoods in the city of Malmö, Sweden in 2006. We study two individual outcomes (psychotropic drug use and choice of private vs. public general practitioner, GP for which the relative importance of neighbourhood as a source of individual variation differs substantially. In Step 1 of the analysis, we evaluate the OR and the area under the receiver operating characteristic (AUC curve for individual-level covariates (i.e., age, sex and individual low income. In Step 2, we assess general contextual effects using the AUC. Finally, in Step 3 the OR for a specific neighbourhood characteristic (i.e., neighbourhood income is interpreted jointly with the proportional change in variance (i.e., PCV and the proportion of ORs in the opposite direction (POOR statistics.For both outcomes, information on individual characteristics (Step 1 provide a low discriminatory accuracy (AUC = 0.616 for psychotropic drugs; = 0.600 for choosing a private GP. Accounting for neighbourhood of residence (Step 2 only improved the AUC for choosing a private GP (+0.295 units. High neighbourhood income (Step 3 was strongly associated to choosing a private GP (OR = 3.50 but the PCV was only 11% and the POOR 33%.Applying an innovative stepwise multilevel analysis, we observed that, in Malmö, the neighbourhood context per se had a negligible influence on individual use of psychotropic drugs, but

  13. SU-E-J-37: Feasibility of Utilizing Carbon Fiducials to Increase Localization Accuracy of Lumpectomy Cavity for Partial Breast Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Y; Hieken, T; Mutter, R; Park, S; Yan, E; Brinkmann, D; Pafundi, D [Mayo Clinic, Rochester, MN (United States)

    2015-06-15

    Purpose To investigate the feasibility of utilizing carbon fiducials to increase localization accuracy of lumpectomy cavity for partial breast irradiation (PBI). Methods Carbon fiducials were placed intraoperatively in the lumpectomy cavity following resection of breast cancer in 11 patients. The patients were scheduled to receive whole breast irradiation (WBI) with a boost or 3D-conformal PBI. WBI patients were initially setup to skin tattoos using lasers, followed by orthogonal kV on-board-imaging (OBI) matching to bone per clinical practice. Cone beam CT (CBCT) was acquired weekly for offline review. For the boost component of WBI and PBI, patients were setup with lasers, followed by OBI matching to fiducials, with final alignment by CBCT matching to fiducials. Using carbon fiducials as a surrogate for the lumpectomy cavity and CBCT matching to fiducials as the gold standard, setup uncertainties to lasers, OBI bone, OBI fiducials, and CBCT breast were compared. Results Minimal imaging artifacts were introduced by fiducials on the planning CT and CBCT. The fiducials were sufficiently visible on OBI for online localization. The mean magnitude and standard deviation of setup errors were 8.4mm ± 5.3 mm (n=84), 7.3mm ± 3.7mm (n=87), 2.2mm ± 1.6mm (n=40) and 4.8mm ± 2.6mm (n=87), for lasers, OBI bone, OBI fiducials and CBCT breast tissue, respectively. Significant migration occurred in one of 39 implanted fiducials in a patient with a large postoperative seroma. Conclusion OBI carbon fiducial-based setup can improve localization accuracy with minimal imaging artifacts. With increased localization accuracy, setup uncertainties can be reduced from 8mm using OBI bone matching to 3mm using OBI fiducial matching for PBI treatment. This work demonstrates the feasibility of utilizing carbon fiducials to increase localization accuracy to the lumpectomy cavity for PBI. This may be particularly attractive for localization in the setting of proton therapy and other scenarios

  14. SU-E-J-37: Feasibility of Utilizing Carbon Fiducials to Increase Localization Accuracy of Lumpectomy Cavity for Partial Breast Irradiation

    International Nuclear Information System (INIS)

    Purpose To investigate the feasibility of utilizing carbon fiducials to increase localization accuracy of lumpectomy cavity for partial breast irradiation (PBI). Methods Carbon fiducials were placed intraoperatively in the lumpectomy cavity following resection of breast cancer in 11 patients. The patients were scheduled to receive whole breast irradiation (WBI) with a boost or 3D-conformal PBI. WBI patients were initially setup to skin tattoos using lasers, followed by orthogonal kV on-board-imaging (OBI) matching to bone per clinical practice. Cone beam CT (CBCT) was acquired weekly for offline review. For the boost component of WBI and PBI, patients were setup with lasers, followed by OBI matching to fiducials, with final alignment by CBCT matching to fiducials. Using carbon fiducials as a surrogate for the lumpectomy cavity and CBCT matching to fiducials as the gold standard, setup uncertainties to lasers, OBI bone, OBI fiducials, and CBCT breast were compared. Results Minimal imaging artifacts were introduced by fiducials on the planning CT and CBCT. The fiducials were sufficiently visible on OBI for online localization. The mean magnitude and standard deviation of setup errors were 8.4mm ± 5.3 mm (n=84), 7.3mm ± 3.7mm (n=87), 2.2mm ± 1.6mm (n=40) and 4.8mm ± 2.6mm (n=87), for lasers, OBI bone, OBI fiducials and CBCT breast tissue, respectively. Significant migration occurred in one of 39 implanted fiducials in a patient with a large postoperative seroma. Conclusion OBI carbon fiducial-based setup can improve localization accuracy with minimal imaging artifacts. With increased localization accuracy, setup uncertainties can be reduced from 8mm using OBI bone matching to 3mm using OBI fiducial matching for PBI treatment. This work demonstrates the feasibility of utilizing carbon fiducials to increase localization accuracy to the lumpectomy cavity for PBI. This may be particularly attractive for localization in the setting of proton therapy and other scenarios

  15. Accuracy of serum uric acid as a predictive test for maternal complications in pre-eclampsia: Bivariate meta-analysis and decision analysis

    NARCIS (Netherlands)

    C.M. Koopmans; M.G. van Pampus; H. Groen; J.G. Aarnoudse; P.P. van den Berg; B.W.J. Mol

    2009-01-01

    The aim of this study is to determine the accuracy and clinical value of serum uric acid in predicting maternal complications in women with pre-eclampsia. An existing meta-analysis on the subject was updated. The accuracy of serum uric acid for the prediction of maternal complications was assessed w

  16. Accuracy of serum uric acid as a predictive test for maternal complications in pre-eclampsia : Bivariate meta-analysis and decision analysis

    NARCIS (Netherlands)

    Koopmans, C.M.; van Pampus, Maria; Groen, H.; Aarnoudse, J.G.; van den Berg, P.P.; Mol, B.W.J.

    2009-01-01

    The aim of this study is to determine the accuracy and clinical value of serum uric acid in predicting maternal complications in women with pre-eclampsia. An existing meta-analysis on the subject was updated. The accuracy of serum uric acid for the prediction of maternal complications was assessed w

  17. Diagnostic accuracy of circulating tumor cells detection in gastric cancer: systematic review and meta-analysis

    International Nuclear Information System (INIS)

    Circulating tumor cells (CTCs) detection has previously been used for diagnosing gastric cancer. However, the previous studies failed to make an agreement whether the detection of CTCs contributes to the diagnosis of gastric cancer. A systematic review and meta-analysis was performed to evaluate the overall accuracy of CTCs detection for diagnosing gastric cancer. PubMed, Embase and the Wanfang database were searched in all languages published up to Oct 2012. The pooled sensitivity (SEN), specificity (SPE), positive and negative likelihood ratios (PLR and NLR, respectively), diagnostic odds ratio (DOR) and summary receiver operating characteristic (sROC) curve were calculated to evaluate the overall test performance. Twenty studies were included in this systematic review and meta-analysis. The diagnostic value of CTCs detection for the gastric cancer was calculated to evaluate the overall test performance. The summary estimates of The pooled sensitivity, specificity, positive and negative likelihood ratios, diagnostic odds ratio were 0.42 (95% confidence interval (CI), 0.21-0.67), 0.99 (95% CI, 0.96-1.00), 58.2 (95% CI, 9.8-345.9), 0.58 (95% CI, 0.38-0.89), and 100 (95% CI, 15–663), respectively. The summary receiver operating characteristic curve was 0.97 (95% CI, 0.95–0.98). Deek’s funnel plot asymmetry test found no evidence of study publication bias in the current study (P = 0.49). This systematic review suggests that CTCs detection alone cannot be recommended as a screening test for gastric cancer. However, it might be used as a noninvasive method for the confirmation of the gastric cancer diagnosis

  18. Accuracy of radiographer plain radiograph reporting in clinical practice: a meta-analysis

    International Nuclear Information System (INIS)

    AIM: To determine the accuracy of radiographer plain radiograph reporting in clinical practice. MATERIALS AND METHODS: Studies were identified from electronic sources and by hand searching journals, personal communication and checking reference lists. Eligible studies assessed radiographers' plain radiograph reporting in clinical practice compared with a reference standard, and provided accuracy data to construct 2x2 contingency tables. Data were extracted on study eligibility and characteristics, quality and accuracy. Summary estimates of sensitivity and specificity and receiver operating characteristic curves were used to pool the accuracy data. RESULTS: Radiographers compared with a reference standard, report plain radiographs in clinical practice at 92.6% and 97.7% sensitivity and specificity, respectively. Studies that compared selectively trained radiographers and radiologists of varying seniority against a reference standard showed no evidence of a difference between radiographer and radiologist reporting accuracy of accident and emergency plain radiographs. Selectively trained radiographers were also found to report such radiographs as accurately as those not solely from accident and emergency, although some variation in reporting accuracy was found for different body areas. Training radiographers improved their accuracy when reporting normal radiographs. CONCLUSION: This study systematically synthesizes the literature to provide an evidence-base showing that radiographers can accurately report plain radiographs in clinical practice

  19. Digital core based transmitted ultrasonic wave simulation and velocity accuracy analysis

    Science.gov (United States)

    Zhu, Wei; Shan, Rui

    2016-06-01

    Transmitted ultrasonic wave simulation (TUWS) in a digital core is one of the important elements of digital rock physics and is used to study wave propagation in porous cores and calculate equivalent velocity. When simulating wave propagates in a 3D digital core, two additional layers are attached to its two surfaces vertical to the wave-direction and one planar wave source and two receiver-arrays are properly installed. After source excitation, the two receivers then record incident and transmitted waves of the digital rock. Wave propagating velocity, which is the velocity of the digital core, is computed by the picked peak-time difference between the two recorded waves. To evaluate the accuracy of TUWS, a digital core is fully saturated with gas, oil, and water to calculate the corresponding velocities. The velocities increase with decreasing wave frequencies in the simulation frequency band, and this is considered to be the result of scattering. When the pore fluids are varied from gas to oil and finally to water, the velocity-variation characteristics between the different frequencies are similar, thereby approximately following the variation law of velocities obtained from linear elastic statics simulation (LESS), although their absolute values are different. However, LESS has been widely used. The results of this paper show that the transmission ultrasonic simulation has high relative precision.

  20. A prospective study to evaluate the accuracy of pulse power analysis to monitor cardiac output in critically ill patients

    Directory of Open Access Journals (Sweden)

    Grounds R Michael

    2008-02-01

    Full Text Available Abstract Background Intermittent measurement of cardiac output may be performed using a lithium dilution technique (LiDCO. This can then be used to calibrate a pulse power algorithm of the arterial waveform which provides a continuous estimate of this variable. The purpose of this study was to examine the duration of accuracy of the pulse power algorithm in critically ill patients with respect to time when compared to measurements of cardiac output by an independent technique. Methods Pulse power analysis was performed on critically ill patients using a proprietary commercial monitor (PulseCO. All measurements were made using an in-dwelling radial artery line and according to manufacturers instructions. Intermittent measurements of cardiac output were made with LiDCO in order to validate the pulse power measurements. These were made at baseline and then following 1, 2, 4 and 8 hours. The LiDCO measurement was considered the reference for comparison in this study. The two methods of measuring cardiac output were then compared by linear regression and a Bland Altman analysis. An error rate for the limits of agreement (LOA between the two techniques of less than 30% was defined as being acceptable for this study. Results 14 critically ill medical and surgical patients were enrolled over a three month period. At baseline patients showed a wide range of cardiac output (median 7.5 L/min, IQR 5.1 -9.0 L/min. The bias and limits of agreement between the two techniques was deemed acceptable for the first four hours of the study with percentage errors being 29%, 22%, and 285 respectively. The percentage error at eight hours following calibration increased to 36%. The ability of the PulseCo to detect changes in cardiac output was assessed with a similar analysis. The PulseCO tracked the changes in cardiac output with adequate accuracy for the first four hours with percentage errors being 20%, 24% and 25%. However at eight hours the error had increased to

  1. Analysis of the Kinematic Accuracy Reliability of a 3-DOF Parallel Robot Manipulator

    OpenAIRE

    Cui, Guohua; Zhang, Haiqiang; Zhang, Dan; Xu, Feng

    2015-01-01

    Kinematic accuracy reliability is an important performance index in the evaluation of mechanism quality. By using a 3- DOF 3-PUU parallel robot manipulator as the research object, the position and orientation error model was derived by mapping the relation between the input and output of the mechanism. Three error sensitivity indexes that evaluate the kinematic accuracy of the parallel robot manipulator were obtained by adapting the singular value decomposition of the error translation matrix...

  2. Image Positioning Accuracy Analysis for the Super Low Altitude Remote Sensing Satellite

    OpenAIRE

    Ming Xu; Nan Zhou

    2012-01-01

    Super low altitude remote sensing satellites maintain lower flight altitudes by means of ion propulsion in order to improve image resolution and positioning accuracy. The use of engineering data in design for achieving image positioning accuracy is discussed in this paper based on the principles of the photogrammetry theory. The exact line‐of‐sight rebuilding of each detection element and this direction precisely intersecting with the Earth’s elliptical when the camera on the satellite is ima...

  3. A 3-dimensional accuracy analysis of chairside CAD/CAM milling processes

    OpenAIRE

    Bosch, Gabriel; Ender, Andreas; Mehl, Albert

    2014-01-01

    STATEMENT OF PROBLEM Milling is a central and important aspect of computer-aided design and computer-aided manufacturing (CAD/CAM) technology. High milling accuracy reduces the time needed to adapt the workpiece and provides restorations with better longevity and esthetic appeal. The influence of different milling processes on the accuracy of milled restorations has not yet been reviewed. PURPOSE The purpose of this study was to investigate the influence of different milling processes on t...

  4. Nonlinearity for a parallel kinematic machine tool and its application to interpolation accuracy analysis

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    [1]Carlo,I.,Direct Position Analysis of The Stewart Platform Mechanism,Mech.Mach.Theory,1990,25(6): 611-621.[2]Fitchter,E.F.,A Stewart platform based manipulator general theory and practical construction,Inter.Journal of Robtics Research,1986,(2): 157-182.[3]Raghavan,M.,The Stewart platform of general geometry has 40 configurations,ASME J.Mechanical Design,1993,115(2): 277-281.[4]Wampler,C.W.,Forward displacement analysis of general six-in-parallel SPS (Stewart) platform manipulators using SOMA Coordinates,Mech.Mach.Theory,1995,31(3): 331-337.[5]Wen,F.A.,Liang,C.G.,Displacement analysis of the 6-6 stewart platform mechanisms,Mech.Mach.Theory,1994,29(4): 547-557.[6]Liang,C.G.,Rong,H.,The forward displacement solution to a Stewart platform type maniputator,China Journal of Mechanical Engineering,1991,27(2): 26-30.[7]Huang,Z.,Spatial Mechanisms,Beijing: China Machine Press,1991.[8]Liu,K.et al.,The singularities and dynamics of a stewart platform manipulator,J.of Intelligent and Robotic Systems,1993,8: 287-308.[9]Bates,D.M.,Watts,D.G.,Relative curvature measures of nonlinearity,Journal of the Royal Statistical Society,1980(B42): 1-25.[10]Huang Tian,Wang Jinsong,Whitehouse,D.J.,Theory and methodology for kinematic design of Gough-Stewart platforms,Science in China,Series E,1999,42(4): 425-436.[11]Wang,Z.H.,Wang,J.S.,Yang,X.D.,Wei,Y.M.,Interpolation scheme and simulation study on its accuracy for a Stewart platform based CNC machine Tool VAMTIY,China Mechanical Engineering,1999,10(10): 1121-1123.[12]Wang Zhonghua,Wang Jinsong,Study on interpolation and its error distribution in workspace for a Stewart platform based CNC machine tool,in Proceedings of International Conference on Advanced Manufacturing Systems and Manufacturing Automation (AMSMA'2000),19th-2st,June,2000,Guangzhou,China.

  5. Diagnostic accuracy of dual-source CT coronary angiography in patients with atrial fibrillation: Meta analysis

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Gang, E-mail: cjr.sungang@vip.163.com [Department of Medical Imaging, Jinan Military General Hospital, No. 25, Shifan Road, Jinan, Shandong Province 250031 (China); Li, Min [Department of Medical Imaging, Jinan Military General Hospital, No. 25, Shifan Road, Jinan, Shandong Province 250031 (China); Jiang, Zhi-wei [Department of Health Statistics, School of Public Health, Fourth Military Medical University, No. 169, Changle West Road, Xi’an, Shaanxi 710032 (China); Xu, Lin [Department of Medical Cardiology, Jinan Military General Hospital, No. 25, Shifan Road, Jinan, Shandong Province 250031 (China); Peng, Zhao-hui; Ding, Juan; Li, Li [Department of Medical Imaging, Jinan Military General Hospital, No. 25, Shifan Road, Jinan, Shandong Province 250031 (China); Jin, Zhi-tao [Department of Cardiology, General Hospital of the Second Artillery, Beijing 100088 (China)

    2013-10-01

    Rationale and objective: To synthesize the available data to underscore the diagnostic accuracy of dual-source CT (DSCT) coronary angiography in patients with atrial fibrillation (AF). Materials and methods: We searched in the electronic databases of PubMed for all published studies that examined patients with AF using DSCT. We used an exact binomial rendition of the bivariate mixed-effects regression model to synthesize the diagnostic data. Results: The positive and negative likelihood ratios (LRs) at the patient level were 6.0 (CI, 3.6–10.1) and 0.03(CI, 0.004–0.2), respectively. The negative predictive values higher than 90% were available for a CAD prevalence <78%. The pooled vessel- and segment-level estimates showed higher positive and negative LRs than the patient-level estimates (15.3 [CI, 9.8–23.9] and 0.1 [CI, 0.07–0.3]; 25.1 [CI, 10.8–58.5] and 0.2 [CI, 0.2–0.3], respectively). No statistically significant heterogeneity between studies and publication bias were found at the patient level estimate. A sensitivity analysis showed that no study influenced the pooled results larger than 0.02. Conclusions: Cardiac angiography with DSCT can be applied as an imaging test for ruling out CAD in patient with AF. However, DSCT angiography may be not an effective tool for risk stratification for the high negative LR at the artery and segment levels.

  6. Diagnostic accuracy of dual-source CT coronary angiography in patients with atrial fibrillation: Meta analysis

    International Nuclear Information System (INIS)

    Rationale and objective: To synthesize the available data to underscore the diagnostic accuracy of dual-source CT (DSCT) coronary angiography in patients with atrial fibrillation (AF). Materials and methods: We searched in the electronic databases of PubMed for all published studies that examined patients with AF using DSCT. We used an exact binomial rendition of the bivariate mixed-effects regression model to synthesize the diagnostic data. Results: The positive and negative likelihood ratios (LRs) at the patient level were 6.0 (CI, 3.6–10.1) and 0.03(CI, 0.004–0.2), respectively. The negative predictive values higher than 90% were available for a CAD prevalence <78%. The pooled vessel- and segment-level estimates showed higher positive and negative LRs than the patient-level estimates (15.3 [CI, 9.8–23.9] and 0.1 [CI, 0.07–0.3]; 25.1 [CI, 10.8–58.5] and 0.2 [CI, 0.2–0.3], respectively). No statistically significant heterogeneity between studies and publication bias were found at the patient level estimate. A sensitivity analysis showed that no study influenced the pooled results larger than 0.02. Conclusions: Cardiac angiography with DSCT can be applied as an imaging test for ruling out CAD in patient with AF. However, DSCT angiography may be not an effective tool for risk stratification for the high negative LR at the artery and segment levels

  7. Systematic analysis on the achievable accuracy of PT-PET through automated evaluation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Helmbrecht, Stephan; Stuetzer, Kristin [Technische Univ. Dresden (Germany). OncoRay - National Center for Radiation Research in Oncology; Kuess, Peter; Georg, Dietmar [Medical Univ. Vienna (Austria). Comprehensive Cancer Center; Medical Univ. Vienna (Austria). Christian Doppler Lab. for Medical Radiation Research for Radiation Oncology; Birkfellner, Wolfgang [Medical Univ. Vienna (Austria). Christian Doppler Lab. for Medical Radiation Research for Radiation Oncology; Medical Univ. Vienna (Austria). Center for Medical Physics and Biomedical Engineering; Enghardt, Wolfgang [Technische Univ. Dresden (Germany). OncoRay - National Center for Radiation Research in Oncology; Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany). Inst. of Radiation Oncology; Fiedler, Fine [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany). Inst. of Radiation Physics

    2015-09-01

    Particle Therapy Positron Emission Tomography (PT-PET) is currently the only clinically applied method for in vivo verification of ion-beam radiotherapy during or close in time to the treatment. Since a direct deduction of the delivered dose from the measured activity is not feasible, images are compared to a reference distribution. The achievable accuracy of two image analysis approaches was investigated by means of reproducible phantom benchmark tests. This is an objective method that excludes patient related factors of influence. Two types of phantoms were designed to produce well defined deviations in the activity distributions. Pure range differences were simulated using the first phantom type while the other emulated cavity structures. The phantoms were irradiated with {sup 12}C-ions. PT-PET measurements were performed by means of a camera system installed at the beamline. Different measurement time scenarios were investigated, assuming a PET scanner directly at the irradiation site or placed within the treatment room. The images were analyzed by means of the Pearson Correlation Coefficient (PCC) and a range calculation algorithm combined with a dedicated cavity filling detection method. Range differences could be measured with an error of less than 2 mm. The range comparison algorithm yielded slightly better results than the PCC method. The filling of a cavity structure could be safely detected if its inner diameter was at least 5 mm. Both approaches evaluate the PT-PET data in an objective way and deliver promising results for in-beam and in-room PET for clinical realistic dose rates.

  8. Accuracy and Feasibility of Video Analysis for Assessing Hamstring Flexibility and Validity of the Sit-and-Reach Test

    Science.gov (United States)

    Mier, Constance M.

    2011-01-01

    The accuracy of video analysis of the passive straight-leg raise test (PSLR) and the validity of the sit-and-reach test (SR) were tested in 60 men and women. Computer software measured static hip-joint flexion accurately. High within-session reliability of the PSLR was demonstrated (R greater than 0.97). Test-retest (separate days) reliability for…

  9. An accuracy analysis of Cyberknife tumor tracking radiotherapy according to unpredictable change of respiration

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Jung Min; Lee, Chang Yeol; Huh, Hyun Do; Kim, Wan Sun [Dept. of Radiation Oncology, Inha university hospital, Incheon (Korea, Republic of)

    2015-12-15

    error is a sine curve breathing form, the size of the target of the movement is in response to the 5 mm, 10 mm, 20 mm, respectively, of the average 1.14 ± 0.13 mm, 1.05 ± 0.20 mm, with 2.37 ± 0.17 mm, suddenly for it is variations in breathing, respective average 1.87 ± 0.19 mm, 2.15 ± 0.21 mm, and analyzed with 2.44 ± 0.26 mm. If the correlation error can be defined by the length of the displacement vector in the target track is a sinusoidal breathing mode, the size of the target of the movement in response to 5 mm, 10 mm, 20 mm, respective average 0.84 ± 0.01 mm, 0.70 ± 0.13 mm, with 1.63 ± 0.10 mm, if it is a variant of sudden breathing respective average 0.97 ± 0.06 mm, 1.44 ± 0.11 mm, and analyzed with 1.98 ± 0.10 mm. The larger the correlation error values in both the both the respiratory form, the target error value is large. If the motion size of the target of the sine curve breathing form is greater than or equal to 20 mm, was measured at 1.5 mm or more is a recommendation value of both cyber knife manufacturer of both error value. Conclusion : There is a tendency that the correlation error value between about target error value magnitude of the target motion is large is increased, the error value becomes large in variation of rapid respiration than breathing the form of a sine curve. The more the shape of the breathing large movements regular shape of sine curves target accuracy of the tumor tracking system can be judged to be reduced. Using the algorithm of Cyber-Knife tumor tracking system, when there is a change in the sudden unpredictable respiratory due patient coughing during treatment enforcement is to stop the treatment, it is assumed to carry out the internal target validation process again, it is necessary to readjust the form of respiration. Patients under treatment is determined to be able to improve the treatment of accuracy to induce the observed form of regular breathing and put like to see the goggles monitor capable of the

  10. Perfusion pattern and time of vascularisation with CEUS increase accuracy in differentiating between benign and malignant tumours in 216 musculoskeletal soft tissue masses

    Energy Technology Data Exchange (ETDEWEB)

    De Marchi, Armanda, E-mail: armanda.demarchi@tiscali.it [Department of Imaging, Azienda Ospedaliera Città della Salute e della Scienza, CTO Hospital, Via Zuretti 29, 10126 Torino (Italy); Prever, Elena Brach del, E-mail: elena.brach@unito.it [Department of OrthopaedicOncology and ReconstructiveSurgery, Azienda Ospedaliero Universitaria Città della Salute e della Scienza, CTO Hospital, Via Zuretti 29, 10126 Torino (Italy); Cavallo, Franco, E-mail: franco.cavallo@unito.it [Department of Public health and Paediatrics, University of Turin, Via Santena 5-bis, 10126 Torino (Italy); Pozza, Simona, E-mail: simona.pozza@tin.it [Department of Imaging, Azienda Ospedaliera Città della Salute e della Scienza, CTO Hospital, Via Zuretti 29, 10126 Torino (Italy); Linari, Alessandra, E-mail: linaralessandra@libero.it [Department of Pathology, Azienda Ospedaliero Universitaria Città della Salute e della Scienza, Regina Margherita Hospital, Piazza Polonia, 10126 Torino (Italy); Lombardo, Paolo, E-mail: pao.lombardo82@gmail.com [Department of DiagnosticImaging and Radiotherapy of the University of Turin, Azienda Ospedaliero-Universitaria Città della Salute e della Scienza di Torino, Via Genova 3, 10126 Torino (Italy); Comandone, Alessandro, E-mail: alessandro.comandone@gradenigo.it [Department of Oncology, Gradenigo Hospital, Corso Regina Margherita, 8/10.10153 Torino (Italy); Piana, Raimondo, E-mail: raimondo.piana@libero.it [Department of OrthopaedicOncology and ReconstructiveSurgery, Azienda Ospedaliero Universitaria Città della Salute e della Scienza, CTO Hospital, Via Zuretti 29, 10126 Torino (Italy); Faletti, Carlo [Department of Imaging, Azienda Ospedaliera Città della Salute e della Scienza, CTO Hospital, Via Zuretti 29, 10126 Torino (Italy)

    2015-01-15

    Introduction: Musculoskeletal Soft Tissue Tumours (STT) are frequent heterogeneous lesions. Guidelines consider a mass larger than 5 cm and deep with respect to the deep fascia potentially malignant. Contrast Enhanced Ultrasound (CEUS) can detect both vascularity and tumour neoangiogenesis. We hypothesised that perfusion patterns and vascularisation time could improve the accuracy of CEUS in discriminating malignant tumours from benign lesions. Materials and methods: 216 STT were studied: 40% benign lesions, 60% malignant tumours, 56% in the lower limbs. Seven CEUS perfusion patterns and three types of vascularisation (arterial-venous uptake, absence of uptake) were applied. Accuracy was evaluated by comparing imaging with the histological diagnosis. Univariate and multivariate analysis, Chi-square test and t-test for independent variables were applied; significance was set at p < 0.05 level, 95% computed CI. Results: CEUS pattern 6 (inhomogeneous perfusion), arterial uptake and location in the lower limb were associated with high risk of malignancy. CEUS pattern has PPV 77%, rapidity of vascularisation PPV 69%; location in the limbs is the most sensitive indicator, but NPV 52%, PPV 65%. The combination of CEUS-pattern and vascularisation has 74% PPV, 60% NPV, 70% sensitivity. No correlation with size and location in relation to the deep fascia was found. Conclusion: US with CEUS qualitative analysis could be an accurate technique to identify potentially malignant STT, for which second line imaging and biopsy are indicated in Referral Centers. Intense inhomogeneous enhancement with avascular areas and rapid vascularisation time could be useful in discriminating benign from malignant SST, overall when the lower limbs are involved.

  11. A Comparative Study of Measurement Accuracy of Cyber Space Analysis Software with Manual Method in Mixed Dentition

    Directory of Open Access Journals (Sweden)

    Sheibani Nia A.

    2011-04-01

    Full Text Available Statement of Problem: One of the considerations regarding the space analysis in study casts is the issue of speed and precision in analysis.Purpose: This research aimed to design a software to conduct space analysis and evaluate its accuracy compared to manual space analysis.Materials and Method: This reasearch was conducted in two stages: Exploratory and Cross- Sectional. The subjects were selected randomly from patients between 7 to 11 years of age referring to the orthodontics clinic at the dentistry school of the Islamic Azad University. About 30 study models (15 pairs were randomly selected. Space analysis with manual method was performed .Space analysis with the aid of Cyber Space Analysis software was also carried out by locating the required landmarks on digital images of dental casts. The accuracy of this software in comparison with the manual method in space analysis for mixed dentition was evaluated using T student test.Results: The average time required for space analysis using the software was 3.4 minutes as compared to the manual method which took 7.81 minutes on average. The results from software-assisted space analysis showed no significant difference with that obtained from the manual method ( p < 0.0001.Conclusion: The results from software-assisted space analysis were similar to those of the manual method. However, software-assisted space analysis is carried out more quickly than the manual method.

  12. Diagnostic test accuracy: methods for systematic review and meta-analysis.

    Science.gov (United States)

    Campbell, Jared M; Klugar, Miloslav; Ding, Sandrine; Carmody, Dennis P; Hakonsen, Sasja J; Jadotte, Yuri T; White, Sarahlouise; Munn, Zachary

    2015-09-01

    Systematic reviews are carried out to provide an answer to a clinical question based on all available evidence (published and unpublished), to critically appraise the quality of studies, and account for and explain variations between the results of studies. The Joanna Briggs Institute specializes in providing methodological guidance for the conduct of systematic reviews and has developed methods and guidance for reviewers conducting systematic reviews of studies of diagnostic test accuracy. Diagnostic tests are used to identify the presence or absence of a condition for the purpose of developing an appropriate treatment plan. Owing to demands for improvements in speed, cost, ease of performance, patient safety, and accuracy, new diagnostic tests are continuously developed, and there are often several tests available for the diagnosis of a particular condition. In order to provide the evidence necessary for clinicians and other healthcare professionals to make informed decisions regarding the optimum test to use, primary studies need to be carried out on the accuracy of diagnostic tests and the results of these studies synthesized through systematic review. The Joanna Briggs Institute and its international collaboration have updated, revised, and developed new guidance for systematic reviews, including systematic reviews of diagnostic test accuracy. This methodological article summarizes that guidance and provides detailed advice on the effective conduct of systematic reviews of diagnostic test accuracy.

  13. A Software for Space Analysis and Comparison of the Accuracy of Tooth Measurements by Digital and Manual Methods

    OpenAIRE

    Roeinpeikar SMM.; Salehi P.; Pakshir HR.; Emami Z.

    2011-01-01

    Statement of Problems: Several methods have been presented for the prediction of mesiodistal width of the unerupted canines and premolars. Nowadays, application of digital methods is suggested in dental analysis in orthodontics. Purpose: The aim of this study was to design a software for space analysis and comparison of the accuracy of tooth measurements by digital and manual methods in an Iranian population.Material and Method: By using Delphi and C++ programming languages, a software was de...

  14. Breast cancer information on the internet: analysis of accessibility and accuracy.

    LENUS (Irish Health Repository)

    Quinn, E M

    2012-02-18

    Studies show internet sourced information often has poor accuracy. However, it is rapidly becoming a major source of patient information. Our aim was to assess accuracy of breast cancer-related information on the internet. The top five breast cancer-related search terms were identified using the commercial program "Wordtracker". These terms were searched using the search-engine "Google" and the top 100 webpages per topic analysed for applicability and accuracy of information. Overall 500 webpages were analysed. 42% were inapplicable to the question asked. Applicable accuracy rates were variable amongst the five terms: "breast cancer symptoms" 84%, "breast cancer care" 87%, "breast cancer stage" 88%, "breast cancer survival" 91% and "breast cancer signs" 78%. Educational websites were more likely to be accurate(p < 0.001) and interest group administered websites less likely to be accurate(p = 0.018) than other websites. Finding accurate breast cancer information on the internet is difficult due to large numbers of inapplicable unregulated websites preferentially returned via search engines.

  15. High-accuracy identification and bioinformatic analysis of in vivo protein phosphorylation sites in yeast

    DEFF Research Database (Denmark)

    Gnad, Florian; de Godoy, Lyris M F; Cox, Jürgen;

    2009-01-01

    Protein phosphorylation is a fundamental regulatory mechanism that affects many cell signaling processes. Using high-accuracy MS and stable isotope labeling in cell culture-labeling, we provide a global view of the Saccharomyces cerevisiae phosphoproteome, containing 3620 phosphorylation sites ma...

  16. The Push for More Challenging Texts: An Analysis of Early Readers' Rate, Accuracy, and Comprehension

    Science.gov (United States)

    Amendum, Steven J.; Conradi, Kristin; Liebfreund, Meghan D.

    2016-01-01

    The purpose of the study was to examine the relationship between the challenge level of text and early readers' reading comprehension. This relationship was also examined with consideration to students' word recognition accuracy and reading rate. Participants included 636 students, in Grades 1-3, in a southeastern state. Results suggest that…

  17. The Accuracy of Webcams in 2D Motion Analysis: Sources of Error and Their Control

    Science.gov (United States)

    Page, A.; Moreno, R.; Candelas, P.; Belmar, F.

    2008-01-01

    In this paper, we show the potential of webcams as precision measuring instruments in a physics laboratory. Various sources of error appearing in 2D coordinate measurements using low-cost commercial webcams are discussed, quantifying their impact on accuracy and precision, and simple procedures to control these sources of error are presented.…

  18. An Information-Processing Analysis of Children's Accuracy in Predicting the Appearance of Rotated Stimuli.

    Science.gov (United States)

    Rosser, Rosemary A.; And Others

    1984-01-01

    The ability of 40 children four and five years of age to discriminate reflections and rotations of visual stimuli was examined in a kinetic imagery task. Results revealed that prediction accuracy was associated with the existence of orientation markers on the stimuli, as well as age, sex, type of discrimination, and several interactions among the…

  19. Accuracy of Protein Embedding Potentials: An Analysis in Terms of Electrostatic Potentials

    DEFF Research Database (Denmark)

    Olsen, Jogvan Magnus Haugaard; List, Nanna Holmgaard; Kristensen, Kasper;

    2015-01-01

    Quantum-mechanical embedding methods have in recent years gained significant interest and may now be applied to predict a wide range of molecular properties calculated at different levels of theory. To reach a high level of accuracy in embedding methods, both the electronic structure model of the...

  20. Novel molecular and computational methods improve the accuracy of insertion site analysis in Sleeping Beauty-induced tumors.

    Directory of Open Access Journals (Sweden)

    Benjamin T Brett

    Full Text Available The recent development of the Sleeping Beauty (SB system has led to the development of novel mouse models of cancer. Unlike spontaneous models, SB causes cancer through the action of mutagenic transposons that are mobilized in the genomes of somatic cells to induce mutations in cancer genes. While previous methods have successfully identified many transposon-tagged mutations in SB-induced tumors, limitations in DNA sequencing technology have prevented a comprehensive analysis of large tumor cohorts. Here we describe a novel method for producing genetic profiles of SB-induced tumors using Illumina sequencing. This method has dramatically increased the number of transposon-induced mutations identified in each tumor sample to reveal a level of genetic complexity much greater than previously appreciated. In addition, Illumina sequencing has allowed us to more precisely determine the depth of sequencing required to obtain a reproducible signature of transposon-induced mutations within tumor samples. The use of Illumina sequencing to characterize SB-induced tumors should significantly reduce sampling error that undoubtedly occurs using previous sequencing methods. As a consequence, the improved accuracy and precision provided by this method will allow candidate cancer genes to be identified with greater confidence. Overall, this method will facilitate ongoing efforts to decipher the genetic complexity of the human cancer genome by providing more accurate comparative information from Sleeping Beauty models of cancer.

  1. Diagnostic accuracy of ultrasound for rotator cuff tears in adults: A systematic review and meta-analysis

    International Nuclear Information System (INIS)

    Aim: To determine the diagnostic accuracy of ultrasound to detect partial and complete thickness rotator cuff tears based on all available clinical trials. Materials and methods: An electronic search of databases registering published and unpublished literature was conducted. All diagnostic accuracy studies that directly compared the accuracy of ultrasound (the index test) to either arthroscopic or open surgical findings (the reference test) for rotator cuff tear were included. The methodological quality of each included study was assessed using the QUADAS form. When appropriate, pooled sensitivity and specificity analysis was conducted, with an assessment of the summary receiver operating characteristic (ROC) curve for each analysis. Results: Sixty-two studies assessing 6007 patients and 6066 shoulders were included. Ultrasonography had good sensitivity and specificity for the assessment of partial thickness (sensitivity 0.84; specificity 0.89), and full-thickness rotator cuff tears (sensitivity 0.96; specificity 0.93). However, the literature poorly described population characteristics, assessor blinding, and was based on limited sample sizes. The literature assessing transducer frequency was particularly small in size. Conclusion: Ultrasonography is an appropriate radiological technique for the assessment of rotator cuff tears with an acceptable sensitivity and specificity. The diagnostic test accuracy of ultrasound is superior for the detection of full-thickness compared to partial-thickness cuff tears. Further study assessing the effect of transducer frequency is warranted.

  2. Diagnostic accuracy of ultrasound for rotator cuff tears in adults: A systematic review and meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Smith, T.O., E-mail: toby.smith@uea.ac.uk [Department of Physiotherapy, University of East Anglia (United Kingdom); Back, T. [Department of Physiotherapy, Norfolk and Norwich University Hospital, London (United Kingdom); Toms, A.P. [Department of Radiology, Norfolk and Norwich University Hospital, London (United Kingdom); Hing, C.B. [Department of Orthopaedic Surgery, St George' s Hospital, London (United Kingdom)

    2011-11-15

    Aim: To determine the diagnostic accuracy of ultrasound to detect partial and complete thickness rotator cuff tears based on all available clinical trials. Materials and methods: An electronic search of databases registering published and unpublished literature was conducted. All diagnostic accuracy studies that directly compared the accuracy of ultrasound (the index test) to either arthroscopic or open surgical findings (the reference test) for rotator cuff tear were included. The methodological quality of each included study was assessed using the QUADAS form. When appropriate, pooled sensitivity and specificity analysis was conducted, with an assessment of the summary receiver operating characteristic (ROC) curve for each analysis. Results: Sixty-two studies assessing 6007 patients and 6066 shoulders were included. Ultrasonography had good sensitivity and specificity for the assessment of partial thickness (sensitivity 0.84; specificity 0.89), and full-thickness rotator cuff tears (sensitivity 0.96; specificity 0.93). However, the literature poorly described population characteristics, assessor blinding, and was based on limited sample sizes. The literature assessing transducer frequency was particularly small in size. Conclusion: Ultrasonography is an appropriate radiological technique for the assessment of rotator cuff tears with an acceptable sensitivity and specificity. The diagnostic test accuracy of ultrasound is superior for the detection of full-thickness compared to partial-thickness cuff tears. Further study assessing the effect of transducer frequency is warranted.

  3. Multidimensional analysis of suction feeding performance in fishes: fluid speed, acceleration, strike accuracy and the ingested volume of water.

    Science.gov (United States)

    Higham, Timothy E; Day, Steven W; Wainwright, Peter C

    2006-07-01

    Suction feeding fish draw prey into the mouth using a flow field that they generate external to the head. In this paper we present a multidimensional perspective on suction feeding performance that we illustrate in a comparative analysis of suction feeding ability in two members of Centrarchidae, the largemouth bass (Micropterus salmoides) and bluegill sunfish (Lepomis macrochirus). We present the first direct measurements of maximum fluid speed capacity, and we use this to calculate local fluid acceleration and volumetric flow rate. We also calculated the ingested volume and a novel metric of strike accuracy. In addition, we quantified for each species the effects of gape magnitude, time to peak gape, and swimming speed on features of the ingested volume of water. Digital particle image velocimetry (DPIV) and high-speed video were used to measure the flow in front of the mouths of three fish from each species in conjunction with a vertical laser sheet positioned on the mid-sagittal plane of the fish. From this we quantified the maximum fluid speed (in the earthbound and fish's frame of reference), acceleration and ingested volume. Our method for determining strike accuracy involved quantifying the location of the prey relative to the center of the parcel of ingested water. Bluegill sunfish generated higher fluid speeds in the earthbound frame of reference, accelerated the fluid faster, and were more accurate than largemouth bass. However, largemouth bass ingested a larger volume of water and generated a higher volumetric flow rate than bluegill sunfish. In addition, because largemouth bass swam faster during prey capture, they generated higher fluid speeds in the fish's frame of reference. Thus, while bluegill can exert higher drag forces on stationary prey items, largemouth bass more quickly close the distance between themselves and prey. The ingested volume and volumetric flow rate significantly increased as gape increased for both species, while time to peak

  4. Spatio-temporal analysis of the accuracy of tropical multisatellite precipitation analysis 3B42 precipitation data in mid-high latitudes of China.

    Directory of Open Access Journals (Sweden)

    Yancong Cai

    Full Text Available Satellite-based precipitation data have contributed greatly to quantitatively forecasting precipitation, and provides a potential alternative source for precipitation data allowing researchers to better understand patterns of precipitation over ungauged basins. However, the absence of calibration satellite data creates considerable uncertainties for The Tropical Rainfall Measuring Mission (TRMM Multisatellite Precipitation Analysis (TMPA 3B42 product over high latitude areas beyond the TRMM satellites latitude band (38°NS. This study attempts to statistically assess TMPA V7 data over the region beyond 40°NS using data obtained from numerous weather stations in 1998-2012. Comparative analysis at three timescales (daily, monthly and annual scale indicates that adoption of a monthly adjustment significantly improved correlation at a larger timescale increasing from 0.63 to 0.95; TMPA data always exhibits a slight overestimation that is most serious at a daily scale (the absolute bias is 103.54%. Moreover, the performance of TMPA data varies across all seasons. Generally, TMPA data performs best in summer, but worst in winter, which is likely to be associated with the effects of snow/ice-covered surfaces and shortcomings of precipitation retrieval algorithms. Temporal and spatial analysis of accuracy indices suggest that the performance of TMPA data has gradually improved and has benefited from upgrades; the data are more reliable in humid areas than in arid regions. Special attention should be paid to its application in arid areas and in winter with poor scores of accuracy indices. Also, it is clear that the calibration can significantly improve precipitation estimates, the overestimation by TMPA in TRMM-covered area is about a third as much as that in no-TRMM area for monthly and annual precipitation. The systematic evaluation of TMPA over mid-high latitudes provides a broader understanding of satellite-based precipitation estimates, and these

  5. The accuracy of webcams in 2D motion analysis: sources of error and their control

    Energy Technology Data Exchange (ETDEWEB)

    Page, A; Candelas, P; Belmar, F [Departamento de Fisica Aplicada, Universidad Politecnica de Valencia, Valencia (Spain); Moreno, R [Instituto de Biomecanica de Valencia, Valencia (Spain)], E-mail: alvaro.page@ibv.upv.es

    2008-07-15

    In this paper, we show the potential of webcams as precision measuring instruments in a physics laboratory. Various sources of error appearing in 2D coordinate measurements using low-cost commercial webcams are discussed, quantifying their impact on accuracy and precision, and simple procedures to control these sources of error are presented. Finally, an experiment with controlled movement is performed to experimentally measure the errors described above and to assess the effectiveness of the proposed corrective measures. It will be shown that when these aspects are considered, it is possible to obtain errors lower than 0.1%. This level of accuracy demonstrates that webcams should be considered as very precise and accurate measuring instruments at a remarkably low cost.

  6. Accuracy of frozen section diagnosis: a retrospective analysis of 4785 cases

    DEFF Research Database (Denmark)

    Winther, Charlotte; Graem, Niels

    2011-01-01

    During a 1-year period 4785 intraoperative consultations were performed. The pathology reports were retrospectively reviewed to determine the accuracy of frozen section diagnosis in various tissue types. Skin for evaluation of section margins and axillary sentinel lymph nodes for evaluation...... of deferred specimens was 57. The accuracy of frozen section diagnosis varied between tissue types, and axillary sentinel lymph nodes accounted for the greatest number of discordances. In conclusion, the frozen section diagnosis is a reliable method with varying concordance and deferral rates between tissue...... of metastatic disease were most frequently sent for frozen section diagnosis. The number of discordant cases were 182, 178 were false negative and four were false positive. When frozen section diagnoses were compared with permanent section diagnoses, the overall diagnostic concordance was 95.1%. The number...

  7. Accuracy analysis of hybrid parallel robot for the assembling of ITER

    International Nuclear Information System (INIS)

    This paper presents a novel mobile parallel robot, which is able to carry welding and machining processes from inside the international thermonuclear experimental reactor (ITER) vacuum vessel (VV). The kinematics design of the robot has been optimized for ITER access. To improve the accuracy of the parallel robot, the errors caused by the stiffness and manufacture process have to be compensated or limited to a minimum value. In this paper kinematics errors and stiffness modeling are given. The simulation results are presented.

  8. Accuracy of ionospheric models used in GNSS and SBAS: methodology and analysis

    OpenAIRE

    Rovira Garcia, Adrià; Juan Zornoza, José Miguel; Sanz Subirana, Jaume; González Casado, Guillermo; Ibáñez Segura, Deimos

    2016-01-01

    © 2015, Springer-Verlag Berlin Heidelberg. The characterization of the accuracy of ionospheric models currently used in global navigation satellite systems (GNSSs) is a long-standing issue. The characterization remains a challenging problem owing to the lack of sufficiently accurate slant ionospheric determinations to be used as a reference. The present study proposes a methodology based on the comparison of the predictions of any ionospheric model with actual unambiguous carrier-phase measur...

  9. Orbit determination and prediction accuracy analysis for a regional tracking network

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    China’s COMPASS satellite navigation system relies on a regional tracking network to provide navigation services. Limited by its geographic border,the regional network is able to cover only 30% of the medium-earth-orbits(MEO). Accuracy of determined and predicted orbits is not able to satisfy system requirements if the tracking data processing strategy for global tracking network processing is used for the regional network. Two major error sources for orbital prediction are accuracy of initial orbital elements and dynamical modeling. To achieve better prediction accuracy,we propose a two-step orbit determination and prediction strategy. For step 1,only solar radiation pressure(SRP) parameters are estimated along with the orbital elements and other parameters; for step 2,all parameters are estimated but the SRP parameters are tightly constrained to their step 1 estimates. Experimenting with data from a regional GPS network,we conclude for orbital prediction using the proposed two-step strategy,the average user range error(URE) for 24-h prediction arcs is better than 0.6 m.

  10. Accuracy in categorizing perceptually ambiguous groups: a review and meta-analysis.

    Science.gov (United States)

    Tskhay, Konstantin O; Rule, Nicholas O

    2013-02-01

    Since the 1940s, social psychologists have conducted research testing whether it is possible to accurately identify members of perceptually ambiguous groups. This study quantitatively reviews the research on the perception of ambiguous groups to better understand the human capacity to accurately identify others based on very subtle nonverbal cues. Standard random-effects meta-analytic techniques were used to examine the distinctions between different target groups in terms of their identifiability, as well as to compare rates of accuracy across perceptual modalities (e.g., photographs, audio, video) and other study design differences. Overall, the accuracy of identifying targets was significantly better than chance guessing (i.e., 64.5%). Furthermore, stimulus modality was found to be a moderator of accuracy. Other moderators (e.g., time of exposure, analytic approach) were identified and examined. These data help to document and characterize broad trends in the proliferating and expanding study of the perception and categorization of ambiguous social groups. PMID:23070218

  11. Parameter Deduction and Accuracy Analysis of Track Beam Curves in Straddle-type Monorail Systems

    Directory of Open Access Journals (Sweden)

    Xiaobo Zhao

    2015-12-01

    Full Text Available The accuracy of the bottom curve of a PC track beam is strongly related to the production quality of the entire beam. Many factors may affect the parameters of the bottom curve, such as the superelevation of the curve and the deformation of a PC track beam. At present, no effective method has been developed to determine the bottom curve of a PC track beam; therefore, a new technique is presented in this paper to deduce the parameters of such a curve and to control the accuracy of the computation results. First, the domain of the bottom curve of a PC track beam is assumed to be a spindle plane. Then, the corresponding supposed top curve domain is determined based on a geometrical relationship that is the opposite of that identified by the conventional method. Second, several optimal points are selected from the supposed top curve domain according to the dichotomy algorithm; the supposed top curve is thus generated by connecting these points. Finally, one rigorous criterion is established in the fractal dimension to assess the accuracy of the assumed top curve deduced in the previous step. If this supposed curve coincides completely with the known top curve, then the assumed bottom curve corresponding to the assumed top curve is considered to be the real bottom curve. This technique of determining the bottom curve of a PC track beam is thus proven to be efficient and accurate.

  12. Diagnostic Accuracy of Computer based Tests for Attention-Deficit Hyperactivity Disorder: A Receiver-Operating Characteristic Analysis

    Directory of Open Access Journals (Sweden)

    Thomas Dreisörner

    2011-05-01

    Full Text Available Objectives: Attention-Deficit Hyperactivity Disorder (ADHD is one of the most common neurobehavioral diagnosis affecting children today. Guidelines of child psychiatry encourage clinicians to employ clinical interviews and questionnaires, learning and performance tests and behavior observation in making the diagnosis. Special attention tests can be conducted additionally. Computer-based attention tests constitute a promising method to do so as they appeal to children. In clinical practise in Germany two test batteries are commonly used: “Testbatterie zur Aufmerksamkeitsprüfung” (TAP and “Testbatterie zur Aufmerksamkeitsprüfung für Kinder” (KITAP. The latter having been adapted to the motivational needs of children. This study aims at examining the diagnostic accuracy of the TAP and KITAP. Methods: ROC-analysis of TAP- and KITAP parameters and logistic regressions were conducted in a sample of 24 children with and without ADHD. Results: Both TAP and KITAP proved to differentiate between children with and without ADHD. TAP parameters possessed a higher discriminating power for ADHD. In logistic regression analysis TAP parameters led to an amount of variance of 32.5% (KITAP: 21.6% and correct classification rate of 75% (KITAP: 72.9%. Adding KITAP parameters did not improve the amount of variance significantly whereas adding TAP parameters to the KITAP data did result in a significant increase. Conclusion: These findings suggest that TAP and KITAP could serve as useful additional test instruments to help identify cases likely to meet criteria for ADHD in clinical settings. For individual diagnosis TAP and KITAP lack cut-off criteria and substantial classification rates.

  13. Implementation of the European multicentre database of healthy controls for [(123)I]FP-CIT SPECT increases diagnostic accuracy in patients with clinically uncertain parkinsonian syndromes

    DEFF Research Database (Denmark)

    Albert, Nathalie L; Unterrainer, Marcus; Diemling, Markus;

    2016-01-01

    PURPOSE: Even though [(123)I]FP-CIT SPECT provides high accuracy in detecting nigrostriatal cell loss in neurodegenerative parkinsonian syndromes (PS), some patients with an inconclusive diagnosis remain. We investigated whether the diagnostic accuracy in patients with clinically uncertain PS wit...

  14. Analysis of the dose calculation accuracy for IMRT in lung: A 2D approach

    Energy Technology Data Exchange (ETDEWEB)

    Dvorak, Pavel; Stock, Markus; Kroupa, Bernhard; Bogner, Joachim; Georg, Diet mar [Div. of Medical Radiation Physics, Dept. of Radiotherapy and Radiobiology, AKH Vienna, Medical Univ. Vienna, Vienna (Austria)

    2007-10-15

    The purpose of this study was to compare the dosimetric accuracy of IMRT plans for targets in lung with the accuracy of standard uniform-intensity conformal radiotherapy for different dose calculation algorithms. Tests were performed utilizing a special phantom manufactured from cork and polystyrene in order to quantify the uncertainty of two commercial TPS for IMRT in the lung. Ionization and film measurements were performed at various measuring points/planes. Additionally, single-beam and uniform-intensity multiple-beam tests were performed, in order to investigate deviations due to other characteristics of IMRT. Helax-TMS V6.1(A) was tested for 6, 10 and 25 MV and BrainSCAN 5.2 for 6 MV photon beams, respectively. Pencil beam (PB) with simple inhomogeneity correction and 'collapsed cone' (CC) algorithms were applied for dose calculations. However, the latter was not incorporated during optimization hence only post-optimization recalculation was tested. Two-dimensional dose distributions were evaluated applying the b.gamma index concept. Conformal plans showed the same accuracy as IMRT plans. Ionization chamber measurements detected deviations of up to 5% when a PB algorithm was used for IMRT dose calculations. Significant improvement was observed when IMRT plans were recalculated with the CC algorithm, especially for the highest nominal energy. All b.gamma evaluations confirmed substantial improvement with the CC algorithm in 2D. While PB dose distributions showed most discrepancies in lower (<50%) and high (>90%) dose regions, the CC dose distributions deviated mainly in the high dose gradient (20-80%) region. The advantages of IMRT (conformity, intra-target dose control) should be counterbalanced with possible calculation inaccuracies for targets in the lung. Until no superior dose calculation algorithms are involved in the iterative optimization process it should be used with great care. When only PB algorithm with simple inhomogeneity correction is

  15. Analysis of the dose calculation accuracy for IMRT in lung: a 2D approach.

    Science.gov (United States)

    Dvorak, Pavel; Stock, Markus; Kroupa, Bernhard; Bogner, Joachim; Georg, Dietmar

    2007-01-01

    The purpose of this study was to compare the dosimetric accuracy of IMRT plans for targets in lung with the accuracy of standard uniform-intensity conformal radiotherapy for different dose calculation algorithms. Tests were performed utilizing a special phantom manufactured from cork and polystyrene in order to quantify the uncertainty of two commercial TPS for IMRT in the lung. Ionization and film measurements were performed at various measuring points/planes. Additionally, single-beam and uniform-intensity multiple-beam tests were performed, in order to investigate deviations due to other characteristics of IMRT. Helax-TMS V6.1(A) was tested for 6, 10 and 25 MV and BrainSCAN 5.2 for 6 MV photon beams, respectively. Pencil beam (PB) with simple inhomogeneity correction and 'collapsed cone' (CC) algorithms were applied for dose calculations. However, the latter was not incorporated during optimization hence only post-optimization recalculation was tested. Two-dimensional dose distributions were evaluated applying the gamma index concept. Conformal plans showed the same accuracy as IMRT plans. Ionization chamber measurements detected deviations of up to 5% when a PB algorithm was used for IMRT dose calculations. Significant improvement (deviations approximately 2%) was observed when IMRT plans were recalculated with the CC algorithm, especially for the highest nominal energy. All gamma evaluations confirmed substantial improvement with the CC algorithm in 2D. While PB dose distributions showed most discrepancies in lower (90%) dose regions, the CC dose distributions deviated mainly in the high dose gradient (20-80%) region. The advantages of IMRT (conformity, intra-target dose control) should be counterbalanced with possible calculation inaccuracies for targets in the lung. Until no superior dose calculation algorithms are involved in the iterative optimization process it should be used with great care. When only PB algorithm with simple inhomogeneity correction is

  16. Analysis of the dose calculation accuracy for IMRT in lung: A 2D approach

    International Nuclear Information System (INIS)

    The purpose of this study was to compare the dosimetric accuracy of IMRT plans for targets in lung with the accuracy of standard uniform-intensity conformal radiotherapy for different dose calculation algorithms. Tests were performed utilizing a special phantom manufactured from cork and polystyrene in order to quantify the uncertainty of two commercial TPS for IMRT in the lung. Ionization and film measurements were performed at various measuring points/planes. Additionally, single-beam and uniform-intensity multiple-beam tests were performed, in order to investigate deviations due to other characteristics of IMRT. Helax-TMS V6.1(A) was tested for 6, 10 and 25 MV and BrainSCAN 5.2 for 6 MV photon beams, respectively. Pencil beam (PB) with simple inhomogeneity correction and 'collapsed cone' (CC) algorithms were applied for dose calculations. However, the latter was not incorporated during optimization hence only post-optimization recalculation was tested. Two-dimensional dose distributions were evaluated applying the b.gamma index concept. Conformal plans showed the same accuracy as IMRT plans. Ionization chamber measurements detected deviations of up to 5% when a PB algorithm was used for IMRT dose calculations. Significant improvement was observed when IMRT plans were recalculated with the CC algorithm, especially for the highest nominal energy. All b.gamma evaluations confirmed substantial improvement with the CC algorithm in 2D. While PB dose distributions showed most discrepancies in lower (90%) dose regions, the CC dose distributions deviated mainly in the high dose gradient (20-80%) region. The advantages of IMRT (conformity, intra-target dose control) should be counterbalanced with possible calculation inaccuracies for targets in the lung. Until no superior dose calculation algorithms are involved in the iterative optimization process it should be used with great care. When only PB algorithm with simple inhomogeneity correction is used, lower energy photon

  17. Increased accuracy of the carbon-14 D-xylose breath test in detecting small-intestinal bacterial overgrowth by correction with the gastric emptying rate

    International Nuclear Information System (INIS)

    The aim of this study was to determine whether the accuracy of 14C-D-xylose breath test for detecting bacterial overgrowth can be increased by correction with the gastric emptying rate of 14C-D-xylose. Ten culture-positive patients and ten culture-negative controls were included in the study. Small-intestinal aspirates for bacteriological culture were obtained endoscopically. A liquid-phase gastric emptying study was performed simultaneously to assess the amount of 14C-D-xylose that entered the small intestine. The results of the percentage of expired 14CO2 at 30 min were corrected with the amount of 14C-D-xylose that entered the small intestine. There were six patients in the culture-positive group with a 14CO2 concentration above the normal limit. Three out of four patients with initially negative results using the uncorrected method proved to be positive after correction. All these three patients had prolonged gastric emptying of 14C-D-xylose. When compared with cultures of small-intestine aspirates, the sensitivity and specificity of the uncorrected 14C-D-xylose breath test were 60% and 90%, respectively. In contrast, the sensitivity and specificity of the corrected 14C-D-xylose breath test improved to 90% and 100%, respectively. (orig./MG)

  18. Accuracy assessment of the ERP prediction method based on analysis of 100-year ERP series

    Science.gov (United States)

    Malkin, Z.; Tissen, V. M.

    2012-12-01

    A new method has been developed at the Siberian Research Institute of Metrology (SNIIM) for highly accurate prediction of UT1 and Pole motion (PM). In this study, a detailed comparison was made of real-time UT1 predictions made in 2006-2011 and PMpredictions made in 2009-2011making use of the SNIIM method with simultaneous predictions computed at the International Earth Rotation and Reference Systems Service (IERS), USNO. Obtained results have shown that proposed method provides better accuracy at different prediction lengths.

  19. Relative accuracy evaluation.

    Directory of Open Access Journals (Sweden)

    Yan Zhang

    Full Text Available The quality of data plays an important role in business analysis and decision making, and data accuracy is an important aspect in data quality. Thus one necessary task for data quality management is to evaluate the accuracy of the data. And in order to solve the problem that the accuracy of the whole data set is low while a useful part may be high, it is also necessary to evaluate the accuracy of the query results, called relative accuracy. However, as far as we know, neither measure nor effective methods for the accuracy evaluation methods are proposed. Motivated by this, for relative accuracy evaluation, we propose a systematic method. We design a relative accuracy evaluation framework for relational databases based on a new metric to measure the accuracy using statistics. We apply the methods to evaluate the precision and recall of basic queries, which show the result's relative accuracy. We also propose the method to handle data update and to improve accuracy evaluation using functional dependencies. Extensive experimental results show the effectiveness and efficiency of our proposed framework and algorithms.

  20. Relative accuracy evaluation.

    Science.gov (United States)

    Zhang, Yan; Wang, Hongzhi; Yang, Zhongsheng; Li, Jianzhong

    2014-01-01

    The quality of data plays an important role in business analysis and decision making, and data accuracy is an important aspect in data quality. Thus one necessary task for data quality management is to evaluate the accuracy of the data. And in order to solve the problem that the accuracy of the whole data set is low while a useful part may be high, it is also necessary to evaluate the accuracy of the query results, called relative accuracy. However, as far as we know, neither measure nor effective methods for the accuracy evaluation methods are proposed. Motivated by this, for relative accuracy evaluation, we propose a systematic method. We design a relative accuracy evaluation framework for relational databases based on a new metric to measure the accuracy using statistics. We apply the methods to evaluate the precision and recall of basic queries, which show the result's relative accuracy. We also propose the method to handle data update and to improve accuracy evaluation using functional dependencies. Extensive experimental results show the effectiveness and efficiency of our proposed framework and algorithms. PMID:25133752

  1. Increase in Organization Effectiveness Using Voice Analysis: The System Approach

    Directory of Open Access Journals (Sweden)

    Lina Bartkienė

    2011-04-01

    Full Text Available The main purpose of this article is to analyze literature related to the system theory and to present the system of increase in organization effectiveness using voice analysis. The concepts of the system approach were analyzed, the definition of the system, its components and classification were discussed. Following the principles of the system theory, the system of increase in organization effectiveness using voice analysis was designed. Each element was briefly discussed, i.e. processes influencing the employee, the environment, voice analysis system, expert system, prime and final organizational effectiveness. In addition, the relations between these elements were indentified. Article in Lithuanian

  2. Accuracy analysis of high-order lattice Boltzmann models for rarefied gas flows

    CERN Document Server

    Meng, Jianping

    2009-01-01

    In this work, we have theoretically analyzed and numerically evaluated the accuracy of high-order lattice Boltzmann (LB) models for capturing non-equilibrium effects in rarefied gas flows. In the incompressible limit, the LB equation is proved to be equivalent to the linearized Bhatnagar-Gross-Krook (BGK) equation. Therefore, when the same Gauss-Hermite quadrature is used, LB method closely assembles the discrete velocity method (DVM). In addition, the order of Hermite expansion for the equilibrium distribution function is found not to be correlated with the approximation order in terms of the Knudsen number to the BGK equation, which was previously suggested by \\cite{2006JFM...550..413S}. Furthermore, we have numerically evaluated the LB models for a standing-shear-wave problem, which is designed specifically for assessing model accuracy by excluding the influence of gas molecule/surface interactions at wall boundaries. The numerical simulation results confirm that the high-order terms in the discrete equili...

  3. Meta-analysis for diagnostic accuracy studies: a new statistical model using beta-binomial distributions and bivariate copulas.

    Science.gov (United States)

    Kuss, Oliver; Hoyer, Annika; Solms, Alexander

    2014-01-15

    There are still challenges when meta-analyzing data from studies on diagnostic accuracy. This is mainly due to the bivariate nature of the response where information on sensitivity and specificity must be summarized while accounting for their correlation within a single trial. In this paper, we propose a new statistical model for the meta-analysis for diagnostic accuracy studies. This model uses beta-binomial distributions for the marginal numbers of true positives and true negatives and links these margins by a bivariate copula distribution. The new model comes with all the features of the current standard model, a bivariate logistic regression model with random effects, but has the additional advantages of a closed likelihood function and a larger flexibility for the correlation structure of sensitivity and specificity. In a simulation study, which compares three copula models and two implementations of the standard model, the Plackett and the Gauss copula do rarely perform worse but frequently better than the standard model. We use an example from a meta-analysis to judge the diagnostic accuracy of telomerase (a urinary tumor marker) for the diagnosis of primary bladder cancer for illustration.

  4. Systematic review and meta-analysis of studies evaluating diagnostic test accuracy: A practical review for clinical researchers-Part I. general guidance and tips

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyung Won; Choi, Sang Hyun; Huh, Jimi; Park, Seong Ho [Dept. of Radiology, and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of); Lee, June Young [Dept. of Biostatistics, Korea University College of Medicine, Seoul (Korea, Republic of)

    2015-12-15

    In the field of diagnostic test accuracy (DTA), the use of systematic review and meta-analyses is steadily increasing. By means of objective evaluation of all available primary studies, these two processes generate an evidence-based systematic summary regarding a specific research topic. The methodology for systematic review and meta-analysis in DTA studies differs from that in therapeutic/interventional studies, and its content is still evolving. Here we review the overall process from a practical standpoint, which may serve as a reference for those who implement these methods.

  5. Accuracy Combination Test of Classical and Modern Technical Analysis: A Case Study in Stock of PT Wijaya Karya Tbk

    Directory of Open Access Journals (Sweden)

    Agustini Hamid

    2016-05-01

    Full Text Available The research aimed to measure the accuracy and combination of Classic and Modern Technical Analysis. PT Wijaya Karya Tbk (WIKA’s stock in two periods is the sample of research. Technical analysis was used to predict stock prices by observing changes in historical share price. Practically, technical analysis is divided into Classic Technical and Modern. Research was conducted by library study and using a computer software. Microsft Excel was used for the simulation and Chart Nexus for analyzing Modern Technical Analysis. The research period started in January 1, 2013 until December 31, 2013 and January 1, 2014 until December 31, 2014. The Classic Technical Analysis used Support, Resistance, Trendline, and Flag Patern. Meanwhile for Modern Technical Analysis used Moving Average, Stochastic, Moving Average Convergence Divergence (MACD indicator. The Classical Technical Analysis gave less result than Modern Technical Analysis. The classical give 14 investment decisions in two periods. The average return of Classical Technical is 15,50%. Meanwhile the Modern Technical Analysis gave 18 investment decisions in two periods. The average return of Modern Technical is 18,14%. Combining Classic Technical Analysis and Modern Technical Analysis gave 20 investment decisions with the average rate of return 20,41%.

  6. [Situational low self-esteem in pregnant women: an analysis of accuracy].

    Science.gov (United States)

    Cavalcante, Joyce Carolle Bezerra; de Sousa, Vanessa Emille Carvalho; Lopes, Marcos Venícios de Oliveira

    2012-01-01

    To investigate the accuracy of defining characteristics of Situational low self-esteem we developed a cross-sectional study, with 52 pregnant women assisted in a family centre. The NANDA-I taxonomy was used as well as the Rosenberg's scale. The diagnosis was present in 32.7% of the sample and all characteristics presented statistical significance, except "Reports verbally situational challenge to its own value". The characteristics "Indecisive behavior" and "Helplessness expressions" had 82.35% of sensitivity. On the other hand, the characteristics "Expression of feelings of worthlessness" and "Reports verbally situational challenge to its own value" were the more specific, with 94.29% of specificity. These results can contribute with the nursing practice because the identification of accurate characteristics is essential to a secure inference.

  7. Analysis of Systematic Error Influences on Accuracy of Airborne Laser Scanning Altimetry

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiaohong; LIU Jingnan

    2004-01-01

    The error sources related to the laser rangefinder, GPS and INS are analyzed in details. Several coordinates systems used in airborne laser scanning are set up, and then the basic formula of system is given. This paper emphasizes on discussing the kinematic offset correction between GPS antenna phase center and laser fired point. And kinematic time delay influence on laser footprint position, the ranging errors, positioning errors, attitude errors and integration errors of the system are also explored. Finally, the result shows that the kinematic time delay can be neglected as compared with other error sources. The accuracy of the coordinates is not only influenced by the amplitude of the error, but also controlled by the operation parameters such as flight height, scanning angle amplitude and attitude magnitude of the platform.

  8. Time efficiency and diagnostic accuracy of new automated myocardial perfusion analysis software in 320-row CT cardiac imaging

    International Nuclear Information System (INIS)

    We aimed to evaluate the time efficiency and diagnostic accuracy of automated myocardial computed tomography perfusion (CTP) image analysis software. 320-row CTP was performed in 30 patients, and analyses were conducted independently by three different blinded readers by the use of two recent software releases (version 4.6 and novel version 4.71GR001, Toshiba, Tokyo, Japan). Analysis times were compared, and automated epi- and endocardial contour detection was subjectively rated in five categories (excellent, good, fair, poor and very poor). As semi-quantitative perfusion parameters, myocardial attenuation and transmural perfusion ratio (TPR) were calculated for each myocardial segment and agreement was tested by using the intraclass correlation coefficient (ICC). Conventional coronary angiography served as reference standard. The analysis time was significantly reduced with the novel automated software version as compared with the former release (Reader 1: 43:08 ± 11:39 min vs. 09:47 ± 04:51 min, Reader 2: 42:07 ± 06:44 min vs. 09:42 ± 02:50 min and Reader 3: 21:38 ± 3:44 min vs. 07:34 ± 02:12 min; p < 0.001 for all). Epi- and endocardial contour detection for the novel software was rated to be significantly better (p < 0.001) than with the former software. ICCs demonstrated strong agreement (≥ 0.75) for myocardial attenuation in 93% and for TPR in 82%. Diagnostic accuracy for the two software versions was not significantly different (p 0.169) as compared with conventional coronary angiography. The novel automated CTP analysis software offers enhanced time efficiency with an improvement by a factor of about four, while maintaining diagnostic accuracy.

  9. Accuracy of helical CT for acute pulmonary embolism: ROC analysis of observer performance related to clinical experience

    International Nuclear Information System (INIS)

    The aim of this study was to test the influence of observer experience on the accuracy for interpreting helical CT for acute pulmonary embolism (PE) and to identify sources of observer errors. Three observers of different expertise blindly assessed 147 helical CT scans for suspected PE (true status regarding absence or presence of PE known from independent reference studies). These observers were (a) an experienced CT radiologist, (b) a fellow in CT, and (c) a second-year resident without any formal training in CT. None of them had prior experience with CT for PE. Firstly, 70 CT scans were scored without revealing true PE status. Afterwards, feedback was provided and another 77 CT scans were evaluated. The CT scans were scored on a 5-point confidence scale and receiver-operator-characteristic analysis was performed. Different sources of interpretation errors were analyzed. The two observers with CT experience were significantly more accurate than the unexperienced observer. Their performance was not influenced by feedback training. Certain observer errors were identified, but there was no clear difference among the three observers considering the type of errors. There is significant influence of observer experience on accuracy of reading helical CT for PE: A basic working experience with whole-body CT seems to be a prerequisite. These results suggest that with this experience any radiologist should be able to achieve good accuracy; helical CT thus might become a suitable technique for acute PE in routine clinical practice. (orig.)

  10. 3He lung morphometry technique: Accuracy analysis and pulse sequence optimization

    Science.gov (United States)

    Sukstanskii, A. L.; Conradi, M. S.; Yablonskiy, D. A.

    2010-12-01

    The 3He lung morphometry technique (Yablonskiy et al., JAP, 2009), based on MRI measurements of hyperpolarized gas diffusion in lung airspaces, provides unique information on the lung microstructure at the alveolar level. 3D tomographic images of standard morphological parameters (mean airspace chord length, lung parenchyma surface-to-volume ratio, and the number of alveoli per unit lung volume) can be created from a rather short (several seconds) MRI scan. These parameters are most commonly used to characterize lung morphometry but were not previously available from in vivo studies. A background of the 3He lung morphometry technique is based on a previously proposed model of lung acinar airways, treated as cylindrical passages of external radius R covered by alveolar sleeves of depth h, and on a theory of gas diffusion in these airways. The initial works approximated the acinar airways as very long cylinders, all with the same R and h. The present work aims at analyzing effects of realistic acinar airway structures, incorporating airway branching, physiological airway lengths, a physiological ratio of airway ducts and sacs, and distributions of R and h. By means of Monte-Carlo computer simulations, we demonstrate that our technique allows rather accurate measurements of geometrical and morphological parameters of acinar airways. In particular, the accuracy of determining one of the most important physiological parameter of lung parenchyma - surface-to-volume ratio - does not exceed several percent. Second, we analyze the effect of the susceptibility induced inhomogeneous magnetic field on the parameter estimate and demonstrate that this effect is rather negligible at B0 ⩽ 3T and becomes substantial only at higher B0 Third, we theoretically derive an optimal choice of MR pulse sequence parameters, which should be used to acquire a series of diffusion-attenuated MR signals, allowing a substantial decrease in the acquisition time and improvement in accuracy of the

  11. Diagnostic accuracy of the STRATIFY clinical prediction rule for falls: A systematic review and meta-analysis

    LENUS (Irish Health Repository)

    Billington, Jennifer

    2012-08-07

    AbstractBackgroundThe STRATIFY score is a clinical prediction rule (CPR) derived to assist clinicians to identify patients at risk of falling. The purpose of this systematic review and meta-analysis is to determine the overall diagnostic accuracy of the STRATIFY rule across a variety of clinical settings.MethodsA literature search was performed to identify all studies that validated the STRATIFY rule. The methodological quality of the studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies tool. A STRATIFY score of ≥2 points was used to identify individuals at higher risk of falling. All included studies were combined using a bivariate random effects model to generate pooled sensitivity and specificity of STRATIFY at ≥2 points. Heterogeneity was assessed using the variance of logit transformed sensitivity and specificity.ResultsSeventeen studies were included in our meta-analysis, incorporating 11,378 patients. At a score ≥2 points, the STRATIFY rule is more useful at ruling out falls in those classified as low risk, with a greater pooled sensitivity estimate (0.67, 95% CI 0.52–0.80) than specificity (0.57, 95% CI 0.45 – 0.69). The sensitivity analysis which examined the performance of the rule in different settings and subgroups also showed broadly comparable results, indicating that the STRATIFY rule performs in a similar manner across a variety of different ‘at risk’ patient groups in different clinical settings.ConclusionThis systematic review shows that the diagnostic accuracy of the STRATIFY rule is limited and should not be used in isolation for identifying individuals at high risk of falls in clinical practice.

  12. A Meta-Analysis of Typhoid Diagnostic Accuracy Studies: A Recommendation to Adopt a Standardized Composite Reference.

    Directory of Open Access Journals (Sweden)

    Helen L Storey

    Full Text Available Novel typhoid diagnostics currently under development have the potential to improve clinical care, surveillance, and the disease burden estimates that support vaccine introduction. Blood culture is most often used as the reference method to evaluate the accuracy of new typhoid tests; however, it is recognized to be an imperfect gold standard. If no single gold standard test exists, use of a composite reference standard (CRS can improve estimation of diagnostic accuracy. Numerous studies have used a CRS to evaluate new typhoid diagnostics; however, there is no consensus on an appropriate CRS. In order to evaluate existing tests for use as a reference test or inclusion in a CRS, we performed a systematic review of the typhoid literature to include all index/reference test combinations observed. We described the landscape of comparisons performed, showed results of a meta-analysis on the accuracy of the more common combinations, and evaluated sources of variability based on study quality. This wide-ranging meta-analysis suggests that no single test has sufficiently good performance but some existing diagnostics may be useful as part of a CRS. Additionally, based on findings from the meta-analysis and a constructed numerical example demonstrating the use of CRS, we proposed necessary criteria and potential components of a typhoid CRS to guide future recommendations. Agreement and adoption by all investigators of a standardized CRS is requisite, and would improve comparison of new diagnostics across independent studies, leading to the identification of a better reference test and improved confidence in prevalence estimates.

  13. Accuracy and concurrent validity of a sensor-based analysis of sit-to-stand movements in older adults.

    Science.gov (United States)

    Regterschot, G Ruben H; Zhang, Wei; Baldus, Heribert; Stevens, Martin; Zijlstra, Wiebren

    2016-03-01

    Body-fixed motion sensors have been applied for the assessment of sit-to-stand (STS) performance. However, the accuracy and concurrent validity of sensor-based estimations of the body's center of mass (CoM) motion during STS are unclear. Therefore, this study investigated the accuracy and concurrent validity of sensor-based measures of CoM motion during STS in older adults. Accuracy and concurrent validity were investigated by comparing the sensor-based method to a force plate method. Twenty-seven older adults (20 females, 7 males; age: 72-94 years) performed five STS movements while data were collected with force plates and motion sensors on the hip and chest. Hip maximal acceleration provided an accurate estimation of the center of mass (CoM) maximal acceleration (limits of agreement (LOA) smaller than 5% of the CoM maximal acceleration; estimated and real CoM maximal acceleration did not differ (p=0.823)). Other hip STS measures and the chest STS measures did not provide accurate estimations of CoM motion (LOA ranged from -155.6% to 333.3% of the CoM value; sensor-based measures overestimated CoM motion (range p: sensor did not overestimate maximal jerk of the CoM (p=0.679). Moderate to very strong associations were observed between sensor-based estimations and actual CoM motion (range r=0.64-0.94, psensor-based estimations of CoM motion during STS are possible, but accuracy is limited. The sensor-based method cannot replace laboratory methods for a mechanical analysis of CoM motion during STS but it may be a practical alternative for the clinical assessment of STS performance in older persons.

  14. The Accuracy Analysis of Five-planet Movements Recorded in China in the Han Dynasty

    Science.gov (United States)

    Zhang, J.

    2010-04-01

    The observations and researches of five-planet are one of the important part of ancient calendars and also one of the methods to evaluate their accuracies. So astronomers paid much attention to this field. In "Hanshu·Tian wen zhi" and "Xuhanshu· Tian wen zhi", there are 160 records with detailed dates and positions, which are calculated and studied by the modern astronomical method in this paper. The calculated results show that these positions are mostly correct, taking up 77.5% of the total records. While the rest 36 records are incorrect, taking up 22.5%. In addition, there are three typical or special forms of five-planet movements. The numbers of “shou”, “he”, “fan” movements are 14, 22 and 46, taking up 9%, 14% and 29%, respectively. In this paper, a detailed research on these three typical forms of five-planet movements is carried out. We think that the 36 incorrect records are caused by various reasons, but mainly in the data processes carried out by later generations.

  15. Comparative analysis of the processing accuracy of high strength metal sheets by AWJ, laser and plasma

    Science.gov (United States)

    Radu, M. C.; Schnakovszky, C.; Herghelegiu, E.; Tampu, N. C.; Zichil, V.

    2016-08-01

    Experimental tests were carried out on two high-strength steel materials (Ramor 400 and Ramor 550). Quantification of the dimensional accuracy was achieved by measuring the deviations from some geometric parameters of part (two lengths and two radii). It was found that in case of Ramor 400 steel, at the jet inlet, the deviations from the part radii are quite small for all the three analysed processes. Instead for the linear dimensions, the deviations are small only in case of laser cutting. At the jet outlet, the deviations raised in small amount compared to those obtained at the jet inlet for both materials as well as for all the three processes. Related to Ramor 550 steel, at the jet inlet the deviations from the part radii are very small in case of AWJ and laser cutting but larger in case of plasma cutting. At the jet outlet, the deviations from the part radii are very small for all processes; in case of linear dimensions, there was obtained very small deviations only in the case of laser processing, the other two processes leading to very large deviations.

  16. Accuracy analysis of the Null-Screen method for the evaluation of flat heliostats

    Science.gov (United States)

    Cebrian-Xochihuila, P.; Huerta-Carranza, O.; Díaz-Uribe, R.

    2016-04-01

    In this work we develop an algorithm to determinate the accuracy of the Null-Screen Method, used for the testing of flat heliostats used as solar concentrators in a central tower configuration. We simulate the image obtained on a CCD camera when an orderly distribution of points are displayed on a Null-Screen perpendicular to the heliostat under test. The deformations present in the heliostat are represented as a cosine function of the position with different periods and amplitudes. As a resolution criterion, a deformation on the mirror can be detected when the differences in position between the spots on the image plane for the deformed surface as compared with those obtained for an ideally flat heliostat are equal to one pixel. For 6.4μm pixel size and 18mm focal length, the minimum deformation we can measure in the heliostat, correspond to amplitude equal a 122μm for a period equal to 1m; this is equivalent to 0.8mrad in slope. This result depends on the particular configuration used during the test and the size of the heliostat.

  17. Electron Microprobe Analysis of Hf in Zircon: Suggestions for Improved Accuracy of a Difficult Measurement

    Science.gov (United States)

    Fournelle, J.; Hanchar, J. M.

    2013-12-01

    It is not commonly recognized as such, but the accurate measurement of Hf in zircon is not a trivial analytical issue. This is important to assess because Hf is often used as an internal standard for trace element analyses of zircon by LA-ICPMS. The issues pertaining to accuracy revolve around: (1) whether the Hf Ma or the La line is used; (2) what accelerating voltage is applied if Zr La is also measured, and (3) what standard for Hf is used. Weidenbach, et al.'s (2004) study of the 91500 zircon demonstrated the spread (in accuracy) of possible EPMA values for six EPMA labs, 2 of which used Hf Ma, 3 used Hf La, and one used Hf Lb, and standards ranged from HfO2, a ZrO2-HfO2 compound, Hf metal, and hafnon. Weidenbach, et al., used the ID-TIMS values as the correct value (0.695 wt.% Hf.), for which not one of the EPMA labs came close to that value (3 were low and 3 were high). Those data suggest: (1) that there is a systematic underestimation error of the 0.695 wt% Hf (ID-TIMS Hf) value if Hf Ma is used; most likely an issue with the matrix correction, as the analytical lines and absorption edges of Zr La, Si Ka and Hf Ma are rather tightly packed in the electromagnetic spectrum. Mass absorption coefficients are easily in error (e.g., Donovan's determination of the MAC of Hf by Si Ka of 5061 differs from the typically used Henke value of 5449 (Donovan et al, 2002); and (2) For utilization of the Hf La line, however, the second order Zr Ka line interferes with Hf La if the accelerating voltage is greater than 17.99 keV. If this higher keV is used and differential mode PHA is applied, only a portion of the interference is removed (e.g., removal of escape peaks), causing an overestimation of Hf content. Unfortunately, it is virtually impossible to apply an interference correction in this case, as it is impossible to locate Hf-free Zr probe standard. We have examined many of the combinations used by those six EPMA labs and concluded that the optimal EPMA is done with Hf

  18. A proton beam therapy system dedicated to spot-scanning increases accuracy with moving tumors by real-time imaging and gating and reduces equipment size.

    Directory of Open Access Journals (Sweden)

    Shinichi Shimizu

    Full Text Available PURPOSE: A proton beam therapy (PBT system has been designed which dedicates to spot-scanning and has a gating function employing the fluoroscopy-based real-time-imaging of internal fiducial markers near tumors. The dose distribution and treatment time of the newly designed real-time-image gated, spot-scanning proton beam therapy (RGPT were compared with free-breathing spot-scanning proton beam therapy (FBPT in a simulation. MATERIALS AND METHODS: In-house simulation tools and treatment planning system VQA (Hitachi, Ltd., Japan were used for estimating the dose distribution and treatment time. Simulations were performed for 48 motion parameters (including 8 respiratory patterns and 6 initial breathing timings on CT data from two patients, A and B, with hepatocellular carcinoma and with clinical target volumes 14.6 cc and 63.1 cc. The respiratory patterns were derived from the actual trajectory of internal fiducial markers taken in X-ray real-time tumor-tracking radiotherapy (RTRT. RESULTS: With FBPT, 9/48 motion parameters achieved the criteria of successful delivery for patient A and 0/48 for B. With RGPT 48/48 and 42/48 achieved the criteria. Compared with FBPT, the mean liver dose was smaller with RGPT with statistical significance (p<0.001; it decreased from 27% to 13% and 28% to 23% of the prescribed doses for patients A and B, respectively. The relative lengthening of treatment time to administer 3 Gy (RBE was estimated to be 1.22 (RGPT/FBPT: 138 s/113 s and 1.72 (207 s/120 s for patients A and B, respectively. CONCLUSIONS: This simulation study demonstrated that the RGPT was able to improve the dose distribution markedly for moving tumors without very large treatment time extension. The proton beam therapy system dedicated to spot-scanning with a gating function for real-time imaging increases accuracy with moving tumors and reduces the physical size, and subsequently the cost of the equipment as well as of the building housing the

  19. A Software for Space Analysis and Comparison of the Accuracy of Tooth Measurements by Digital and Manual Methods

    Directory of Open Access Journals (Sweden)

    Roeinpeikar SMM.

    2011-08-01

    Full Text Available Statement of Problems: Several methods have been presented for the prediction of mesiodistal width of the unerupted canines and premolars. Nowadays, application of digital methods is suggested in dental analysis in orthodontics. Purpose: The aim of this study was to design a software for space analysis and comparison of the accuracy of tooth measurements by digital and manual methods in an Iranian population.Material and Method: By using Delphi and C++ programming languages, a software was designed. After insertion of 2 dimensional scanned images of dental casts, the software can predict mesiodistal width of the unerupted canines and premolars by using 12-variable regression equations based on the incisors and first molars. After providing 2 dimensional images of 125 dental casts in permanent dentition (75 females and 50 males, the prediction accuracy of regression equations was investigated. By providing 2-dimensional images of dental casts in 50 patients with mixed dentition, the accuracy of dental measurements was evaluated through the designed software. Moreover, the time duration of manual and digital measurements was evaluated. Data was analyzed in SPSS, version 17, using paired sample t-test for comparing the manual and digital measurements and evaluation of interobserver and intraobserver errors.Results: Prediction of the width of the canines and premolars by the designed software was not significantly different from manual measurement of those teeth on dental casts with digital Caliper ( p >0.05. There were no significant differences between manual and digital measurement of mesiodistal width of the teeth ( p >0.05. Also, there were no significant differences between intra-observer and inter-observer measurements and the speed of measurements in digital and manual methods. However, the time duration and speed of space analysis with these two methods were significantly different.Conclusion: The designed software has a good accuracy in

  20. Systematic error analysis and compensation for high accuracy star centroid estimation of star tracker

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Subpixel centroid estimation is the most important star image location method of star tracker. This paper presents a theoretical analysis of the systematic error of subpixel centroid estimation algorithm utilizing frequency domain analysis under the con-sideration of sampling frequency limitation and sampling window limitation. Explicit expression of systematic error of cen-troid estimation is obtained, and the dependence of systematic error on Gaussian width of star image, actual star centroid loca-tion and the number of sampling pixels is derived. A systematic error compensation algorithm for star centroid estimation is proposed based on the result of theoretical analysis. Simulation results show that after compensation, the residual systematic errors of 3-pixel-and 5-pixel-windows’ centroid estimation are less than 2×10-3 pixels and 2×10-4 pixels respectively.

  1. The influence of accuracy, grid size, and interpolation method on the hydrological analysis of LiDAR derived dems: Seneca Nation of Indians, Irving NY

    Science.gov (United States)

    Clarkson, Brian W.

    Light Detection and Ranging (LiDAR) derived Digital Elevation Models (DEMs) provide accurate, high resolution digital surfaces for precise topographic analysis. The following study investigates the accuracy of LiDAR derived DEMs by calculating the Root Mean Square Error (RMSE) of multiple interpolation methods with grid cells ranging from 0.5 to 10-meters. A raster cell with smaller dimensions will drastically increase the amount of detail represented in the DEM by increasing the number of elevation values across the study area. Increased horizontal resolutions have raised the accuracy of the interpolated surfaces and the contours generated from the digitized landscapes. As the raster grid cells decrease in size, the level of detail of hydrological processes will significantly improve compared to coarser resolutions including the publicly available National Elevation Datasets (NEDs). Utilizing a LiDAR derived DEM with the lowest RMSE as the 'ground truth', watershed boundaries were delineated for a sub-basin of the Clear Creek Watershed within the territory of the Seneca Nation of Indians located in Southern Erie County, NY. An investigation of the watershed area and boundary location revealed considerable differences comparing the results of applying different interpretation methods on DEM datasets of different horizontal resolutions. Stream networks coupled with watersheds were used to calculate peak flow values for the 10-meter NEDs and LiDAR derived DEMs.

  2. On the Accuracy of Dynamic and Acoustic Analysis of Lightweight Panel Structures

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Andersen, Lars Vabbersgaard; Dickow, Kristoffer Ahrens

    2012-01-01

    in such buildings is important. In the low-frequency range, prediction of sound and vibration in building structures may be achieved by finite-element analysis (FEA). The aim of this paper is to compare the two commercial codes ABAQUS and ANSYS for FEA of an acoustic-structural coupling in a timber, lightweight...

  3. Factors Related to Sight-Reading Accuracy: A Meta-Analysis

    Science.gov (United States)

    Mishra, Jennifer

    2014-01-01

    The purpose of this meta-analysis was to determine the extent of the overall relationship between previously tested variables and sight-reading. An exhaustive survey of the available research literature was conducted resulting in 92 research studies that reported correlations between sight-reading and another variable. Variables ("n" =…

  4. Effects of a Training Package to Improve the Accuracy of Descriptive Analysis Data Recording

    Science.gov (United States)

    Mayer, Kimberly L.; DiGennaro Reed, Florence D.

    2013-01-01

    Functional behavior assessment is an important precursor to developing interventions to address a problem behavior. Descriptive analysis, a type of functional behavior assessment, is effective in informing intervention design only if the gathered data accurately capture relevant events and behaviors. We investigated a training procedure to improve…

  5. High Accuracy, High Energy He-Erd Analysis of H,C, and T

    International Nuclear Information System (INIS)

    A new analysis technique using high-energy helium ions for the simultaneous elastic recoil detection of all three hydrogen isotopes in metal hydride systems extending to depths of several microm's is presented. Analysis shows that it is possible to separate each hydrogen isotope in a heavy matrix such as erbium to depths of 5 microm using incident 11.48MeV 4He2 ions with a detection system composed of a range foil and ΔE-E telescope detector. Newly measured cross sections for the elastic recoil scattering of 4He2 ions from protons and deuterons are presented in the energy range 10 to 11.75 MeV for the laboratory recoil angle of 30degree

  6. Gravity Probe B Data Analysis. Status and Potential for Improved Accuracy of Scientific Results

    Science.gov (United States)

    Everitt, C. W. F.; Adams, M.; Bencze, W.; Buchman, S.; Clarke, B.; Conklin, J. W.; Debra, D. B.; Dolphin, M.; Heifetz, M.; Hipkins, D.; Holmes, T.; Keiser, G. M.; Kolodziejczak, J.; Li, J.; Lipa, J.; Lockhart, J. M.; Mester, J. C.; Muhlfelder, B.; Ohshima, Y.; Parkinson, B. W.; Salomon, M.; Silbergleit, A.; Solomonik, V.; Stahl, K.; Taber, M.; Turneaure, J. P.; Wang, S.; Worden, P. W.

    2009-12-01

    This is the first of five connected papers detailing progress on the Gravity Probe B (GP-B) Relativity Mission. GP-B, launched 20 April 2004, is a landmark physics experiment in space to test two fundamental predictions of Einstein’s general relativity theory, the geodetic and frame-dragging effects, by means of cryogenic gyroscopes in Earth orbit. Data collection began 28 August 2004 and science operations were completed 29 September 2005. The data analysis has proven deeper than expected as a result of two mutually reinforcing complications in gyroscope performance: (1) a changing polhode path affecting the calibration of the gyroscope scale factor C g against the aberration of starlight and (2) two larger than expected manifestations of a Newtonian gyro torque due to patch potentials on the rotor and housing. In earlier papers, we reported two methods, ‘geometric’ and ‘algebraic’, for identifying and removing the first Newtonian effect (‘misalignment torque’), and also a preliminary method of treating the second (‘roll-polhode resonance torque’). Central to the progress in both torque modeling and C g determination has been an extended effort on “Trapped Flux Mapping” commenced in November 2006. A turning point came in August 2008 when it became possible to include a detailed history of the resonance torques into the computation. The East-West (frame-dragging) effect is now plainly visible in the processed data. The current statistical uncertainty from an analysis of 155 days of data is 5.4 marc-s/yr (˜14% of the predicted effect), though it must be emphasized that this is a preliminary result requiring rigorous investigation of systematics by methods discussed in the accompanying paper by Muhlfelder et al. A covariance analysis incorporating models of the patch effect torques indicates that a 3-5% determination of frame-dragging is possible with more complete, computationally intensive data analysis.

  7. Comprehensive Numerical Analysis of Finite Difference Time Domain Methods for Improving Optical Waveguide Sensor Accuracy

    OpenAIRE

    M. Mosleh E. Abu Samak; Bakar, A. Ashrif A.; Muhammad Kashif; Mohd Saiful Dzulkifly Zan

    2016-01-01

    This paper discusses numerical analysis methods for different geometrical features that have limited interval values for typically used sensor wavelengths. Compared with existing Finite Difference Time Domain (FDTD) methods, the alternating direction implicit (ADI)-FDTD method reduces the number of sub-steps by a factor of two to three, which represents a 33% time savings in each single run. The local one-dimensional (LOD)-FDTD method has similar numerical equation properties, which should be...

  8. Improving Accuracy and Temporal Resolution of Learning Curve Estimation for within- and across-Session Analysis.

    Directory of Open Access Journals (Sweden)

    Matthias Deliano

    Full Text Available Estimation of learning curves is ubiquitously based on proportions of correct responses within moving trial windows. Thereby, it is tacitly assumed that learning performance is constant within the moving windows, which, however, is often not the case. In the present study we demonstrate that violations of this assumption lead to systematic errors in the analysis of learning curves, and we explored the dependency of these errors on window size, different statistical models, and learning phase. To reduce these errors in the analysis of single-subject data as well as on the population level, we propose adequate statistical methods for the estimation of learning curves and the construction of confidence intervals, trial by trial. Applied to data from an avoidance learning experiment with rodents, these methods revealed performance changes occurring at multiple time scales within and across training sessions which were otherwise obscured in the conventional analysis. Our work shows that the proper assessment of the behavioral dynamics of learning at high temporal resolution can shed new light on specific learning processes, and, thus, allows to refine existing learning concepts. It further disambiguates the interpretation of neurophysiological signal changes recorded during training in relation to learning.

  9. Improving Accuracy and Temporal Resolution of Learning Curve Estimation for within- and across-Session Analysis.

    Science.gov (United States)

    Deliano, Matthias; Tabelow, Karsten; König, Reinhard; Polzehl, Jörg

    2016-01-01

    Estimation of learning curves is ubiquitously based on proportions of correct responses within moving trial windows. Thereby, it is tacitly assumed that learning performance is constant within the moving windows, which, however, is often not the case. In the present study we demonstrate that violations of this assumption lead to systematic errors in the analysis of learning curves, and we explored the dependency of these errors on window size, different statistical models, and learning phase. To reduce these errors in the analysis of single-subject data as well as on the population level, we propose adequate statistical methods for the estimation of learning curves and the construction of confidence intervals, trial by trial. Applied to data from an avoidance learning experiment with rodents, these methods revealed performance changes occurring at multiple time scales within and across training sessions which were otherwise obscured in the conventional analysis. Our work shows that the proper assessment of the behavioral dynamics of learning at high temporal resolution can shed new light on specific learning processes, and, thus, allows to refine existing learning concepts. It further disambiguates the interpretation of neurophysiological signal changes recorded during training in relation to learning. PMID:27303809

  10. Multiple Sclerosis Increases Fracture Risk: A Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Guixian Dong

    2015-01-01

    Full Text Available Purpose. The association between multiple sclerosis (MS and fracture risk has been reported, but results of previous studies remain controversial and ambiguous. To assess the association between MS and fracture risk, a meta-analysis was performed. Method. Based on comprehensive searches of the PubMed, Embase, and Web of Science, we identified outcome data from all articles estimating the association between MS and fracture risk. The pooled risk ratios (RRs with 95% confidence intervals (CIs were calculated. Results. A significant association between MS and fracture risk was found. This result remained statistically significant when the adjusted RRs were combined. Subgroup analysis stratified by the site of fracture suggested significant associations between MS and tibia fracture risk, femur fracture risk, hip fracture risk, pelvis fracture risk, vertebrae fracture risk, and humerus fracture risk. In the subgroup analysis by gender, female MS patients had increased fracture risk. When stratified by history of drug use, use of antidepressants, hypnotics/anxiolytics, anticonvulsants, and glucocorticoids increased the risk of fracture risk in MS patients. Conclusions. This meta-analysis demonstrated that MS was significantly associated with fracture risk.

  11. Tourniquet Test for Dengue Diagnosis: Systematic Review and Meta-analysis of Diagnostic Test Accuracy

    OpenAIRE

    Grande, Antonio Jose; Reid, Hamish; Thomas, Emma; Foster, Charlie; Darton, Thomas C

    2016-01-01

    Background Dengue fever is a ubiquitous arboviral infection in tropical and sub-tropical regions, whose incidence has increased over recent decades. In the absence of a rapid point of care test, the clinical diagnosis of dengue is complex. The World Health Organisation has outlined diagnostic criteria for making the diagnosis of dengue infection, which includes the use of the tourniquet test (TT). Purpose To assess the quality of the evidence supporting the use of the TT and perform a diagnos...

  12. Tourniquet Test for Dengue Diagnosis: Systematic Review and Meta-analysis of Diagnostic Test Accuracy.

    OpenAIRE

    Grande, A.J.; Reid, H; Thomas, E.; Foster, C.; Darton, T.C.

    2016-01-01

    BACKGROUND: Dengue fever is a ubiquitous arboviral infection in tropical and sub-tropical regions, whose incidence has increased over recent decades. In the absence of a rapid point of care test, the clinical diagnosis of dengue is complex. The World Health Organisation has outlined diagnostic criteria for making the diagnosis of dengue infection, which includes the use of the tourniquet test (TT). PURPOSE: To assess the quality of the evidence supporting the use of the TT and perform a diagn...

  13. Analysis on Accuracy of Bias, Linearity and Stability of Measurement System in Ball screw Processes by Simulation

    Directory of Open Access Journals (Sweden)

    Fan-Yun Pai

    2015-11-01

    Full Text Available To consistently produce high quality products, a quality management system, such as the ISO9001, 2000 or TS 16949 must be practically implemented. One core instrument of the TS16949 MSA (Measurement System Analysis is to rank the capability of a measurement system and ensure the quality characteristics of the product would likely be transformed through the whole manufacturing process. It is important to reduce the risk of Type I errors (acceptable goods are misjudged as defective parts and Type II errors (defective parts are misjudged as good parts. An ideal measuring system would have the statistical characteristic of zero error, but such a system could hardly exist. Hence, to maintain better control of the variance that might occur in the manufacturing process, MSA is necessary for better quality control. Ball screws, which are a key component in precision machines, have significant attributes with respect to positioning and transmitting. Failures of lead accuracy and axial-gap of a ball screw can cause negative and expensive effects in machine positioning accuracy. Consequently, a functional measurement system can incur great savings by detecting Type I and Type II errors. If the measurement system fails with respect to specification of the product, it will likely misjudge Type I and Type II errors. Inspectors normally follow the MSA regulations for accuracy measurement, but the choice of measuring system does not merely depend on some simple indices. In this paper, we examine the stability of a measuring system by using a Monte Carlo simulation to establish bias, linearity variance of the normal distribution, and the probability density function. Further, we forecast the possible area distribution in the real case. After the simulation, the measurement capability will be improved, which helps the user classify the measurement system and establish measurement regulations for better performance and monitoring of the precision of the ball screw.

  14. Accuracy of Lung Ultrasonography versus Chest Radiography for the Diagnosis of Adult Community-Acquired Pneumonia: Review of the Literature and Meta-Analysis.

    Directory of Open Access Journals (Sweden)

    Xiong Ye

    Full Text Available Lung ultrasonography (LUS is being increasingly utilized in emergency and critical settings. We performed a systematic review of the current literature to compare the accuracy of LUS and chest radiography (CR for the diagnosis of adult community-acquired pneumonia (CAP. We searched in Pub Med, EMBASE dealing with both LUS and CR for diagnosis of adult CAP, and conducted a meta-analysis to evaluate the diagnostic accuracy of LUS in comparison with CR. The diagnostic standard that the index test compared was the hospital discharge diagnosis or the result of chest computed tomography scan as a "gold standard". We calculated pooled sensitivity and specificity using the Mantel-Haenszel method and pooled diagnostic odds ratio using the DerSimonian-Laird method. Five articles met our inclusion criteria and were included in the final analysis. Using hospital discharge diagnosis as reference, LUS had a pooled sensitivity of 0.95 (0.93-0.97 and a specificity of 0.90 (0.86 to 0.94, CR had a pooled sensitivity of 0.77 (0.73 to 0.80 and a specificity of 0.91 (0.87 to 0.94. LUS and CR compared with computed tomography scan in 138 patients in total, the Z statistic of the two summary receiver operating characteristic was 3.093 (P = 0.002, the areas under the curve for LUS and CR were 0.901 and 0.590, respectively. Our study indicates that LUS can help to diagnosis adult CAP by clinicians and the accuracy was better compared with CR using chest computed tomography scan as the gold standard.

  15. Kinematic Accuracy Analysis of Lead Screw W Insertion Mechanism with Flexibility

    Science.gov (United States)

    He, Hu; Zhang, Lei; Kong, Jiayuan

    According to the actual requirements of w insertion, a set of variable lead screw w mechanism was designed, motion characteristics of the mechanism were analyzed and kinematics simulation was carried out with MATLAB. Mechanism precision was analyzed with the analytical method and the error coefficient curve of each component in the mechanism was obtained. Dynamics simulation for rigid mechanism and mechanism with flexibility in different speed was conducted with ADAMS, furthermore, real-time elastic deformation of the flexible Connecting rod was obtained. In consideration of the influences of the elastic connecting rod, the outputs motion error and elastic deformation of components were increased with the speed of the loom.

  16. Accuracy and precision of minimally-invasive cardiac output monitoring in children: a systematic review and meta-analysis.

    Science.gov (United States)

    Suehiro, Koichi; Joosten, Alexandre; Murphy, Linda Suk-Ling; Desebbe, Olivier; Alexander, Brenton; Kim, Sang-Hyun; Cannesson, Maxime

    2016-10-01

    Several minimally-invasive technologies are available for cardiac output (CO) measurement in children, but the accuracy and precision of these devices have not yet been evaluated in a systematic review and meta-analysis. We conducted a comprehensive search of the medical literature in PubMed, Cochrane Library of Clinical Trials, Scopus, and Web of Science from its inception to June 2014 assessing the accuracy and precision of all minimally-invasive CO monitoring systems used in children when compared with CO monitoring reference methods. Pooled mean bias, standard deviation, and mean percentage error of included studies were calculated using a random-effects model. The inter-study heterogeneity was also assessed using an I(2) statistic. A total of 20 studies (624 patients) were included. The overall random-effects pooled bias, and mean percentage error were 0.13 ± 0.44 l min(-1) and 29.1 %, respectively. Significant inter-study heterogeneity was detected (P residual heterogeneity remained after conducting sensitivity and subgroup analyses based on the various study characteristics. By meta-regression analysis, we found no independent effects of study characteristics on weighted mean difference between reference and tested methods. Although the pooled bias was small, the mean pooled percentage error was in the gray zone of clinical applicability. In the sub-group analysis, electrical cardiometry was the device that provided the most accurate measurement. However, a high heterogeneity between studies was found, likely due to a wide range of study characteristics. PMID:26315477

  17. The accuracy of instrumental neutron activation analysis of kilogram-size inhomogeneous samples.

    Science.gov (United States)

    Blaauw, M; Lakmaker, O; van Aller, P

    1997-07-01

    The feasibility of quantitative instrumental neutron activation analysis (INAA) of samples in the kilogram range without internal standardization has been demonstrated by Overwater et al. (Anal. Chem. 1996, 68, 341). In their studies, however, they demonstrated only the agreement between the "corrected" γ ray spectrum of homogeneous large samples and that of small samples of the same material. In this paper, the k(0) calibration of the IRI facilities for large samples is described, and, this time in terms of (trace) element concentrations, some of Overwater's results for homogeneous materials are presented again, as well as results obtained from inhomogeneous materials and subsamples thereof. It is concluded that large-sample INAA can be as accurate as ordinary INAA, even when applied to inhomogeneous materials.

  18. Use of model calibration to achieve high accuracy in analysis of computer networks

    Science.gov (United States)

    Frogner, Bjorn; Guarro, Sergio; Scharf, Guy

    2004-05-11

    A system and method are provided for creating a network performance prediction model, and calibrating the prediction model, through application of network load statistical analyses. The method includes characterizing the measured load on the network, which may include background load data obtained over time, and may further include directed load data representative of a transaction-level event. Probabilistic representations of load data are derived to characterize the statistical persistence of the network performance variability and to determine delays throughout the network. The probabilistic representations are applied to the network performance prediction model to adapt the model for accurate prediction of network performance. Certain embodiments of the method and system may be used for analysis of the performance of a distributed application characterized as data packet streams.

  19. The accuracy of myocardial perfusion imaging using quantitative analysis for patients with coronary artery disease: a Chinese hospital experience

    International Nuclear Information System (INIS)

    Objective: To evaluate the accuracy of automated quantification of myocardial perfusion imaging (MPI) using a method based on a Western normal database for the detection of coronary artery disease (CAD) in a group of Chinese patients. Methods: Seventy-two Chinese patients who underwent coronary angiography (CAG) and MPI within 3 months were recruited into this study. Eighty selected from 140 Chinese patients with low probability of CAD (99Tcm-methoxyisobutylisonitrile (MIBI) MPI using Cedars quantitative perfusion SPECT (QPS) database. Two Western MPI normal databases (CSMC MibiMbiAuto and Mibimibi) were used for processing the Chinese CAD patients recruited in this study, and the results were compared with those using local normal database and visual interpretation. T-test and z-test were used for statistical analysis. Results: The extent (EXT)measurement obtained from Mibimibi and local database was (10.73±14.54)% and (14.22±16.51)%, respectively (t = 7.87, P0.05). Conclusion: Quantification of MPI of our Chinese patients using Western normal database would decrease the accuracy for the detection of CAD. (authors)

  20. Accuracy analysis of the CTBTO nuclear test detection scale and Improvement

    International Nuclear Information System (INIS)

    CTBTO (Comprehensive nuclear Test Ban Treaty Organization) is charge of nuclear test monitoring for nuclear non-proliferation. CTBTO has 170 seismic stations in operation in 76 countries in order to detect the artificial earthquake that was caused by an underground nuclear test. Korea use formula that is based on the equations that are used by the IMS (International Monitoring System) of CTBTO for analysis of explosive scale, and reflect the nature of the terrain, such as rock. But the expression for calculating the exact scale explosive is still un-established state. And generally CTBTO doesn't care about artificial explosive that is being received low-yield in accordance with the criteria of nuclear detection. But, at the time that North Korea conduct a nuclear test, it should not be overlooked that the scale of the earthquake detection criteria below. Because DPRK is trying to conceal their nuclear development capability, there are possibility of low-yield nuclear test or possibility of install a buffer to hide actual explosive scale. These radionuclide observations were consistent with a DPRK low-yield nuclear test on May 2010, even though no seismic signals from such a test have been detected. But there were a few times of low-yield (magnitude 1.39-1.93) occurred around DPRK nuclear test site at that time

  1. Change perspective to increase diagnostic accuracy of ultrasonography in calcium pyrophosphate dihydrate deposition disease! A new approach: the axial scan of the meniscus

    Directory of Open Access Journals (Sweden)

    G. Filippou

    2015-03-01

    Full Text Available Ultrasonography (US is a relevant tool in the study of calcium pyrophosphate dihydrate (CPP deposition disease. However, differential diagnosis of hyperechoic deposits within the fibrocartilage can be difficult; moreover, US study is limited by the need of an adequate acoustic window. We describe a US scanning technique that offers a new viewpoint in the study of knee meniscal structure: a longitudinal scan performed according to the long axis of meniscus. This technique proves to be particularly useful for the identification of CPP deposition, but could also improve the US diagnostic utility and accuracy in other meniscal pathologies.

  2. Modeling and Analysis on Pointing Accuracy of Antenna in Satellite%星载天线指向精度建模与分析

    Institute of Scientific and Technical Information of China (English)

    潘博; 张东华; 史文华; 林恬

    2011-01-01

    随着天线定位机构运动日趋复杂以及对定位机构任务要求的不断提高,提高指向精度已成为星载天线机构能力提升的核心。综合考虑卫星姿态控制误差、展开机构误差、双轴驱动机构误差和反射面误差等因素,利用齐次变换矩阵得到天线指向运动学误差等式,从而得到天线指向精度分析的一般方法。以某星载点波束定位机构为例,对各误差源的影响进行了分析,得到双轴驱动机构任意转角位置下各误差源对最终指向精度的影响,分析结果表明:姿态控制误差、展开机构锁定误差对精度的影响不容忽视,需要综合考虑各部分误差因素,才能从根本上提高天线的指向精度。%With the increase of the complexity of the antenna oriented mechanism and the higher requirement of mission,the improvement of the pointing accuracy has been the core of the capability improvement for satellitic antenna.With a comprehensive consideration of the errors of satellite attitude control,the errors of deployment mechanism,the errors of two-axis drive mechanism and the errors of the reflector,the transformation matrix are used to get the kinematic error equations of antenna pointing.Thus a common method of the analysis on the pointing accuracy of the antenna is obtained.Then the effect of each error is analyzed on a point-beam oriented mechanism of a satellitic antenna,and the effect of each error on the final pointing accuracy is gotten under every rotational position of the two-axis drive mechanism.The results show that the effects on the pointing accuracy of the errors of the satellite attitude control and the locking error of the deployment mechanism cannot be ignored.Therefore,in order to radically improve the pointing accuracy of the antenna,the effect of every error is necessary to take into account comprehensively.

  3. Positioning accuracy analysis for airborne LiDAR%机载LiDAR定位精度分析

    Institute of Scientific and Technical Information of China (English)

    覃昕垚; 张建军; 王勇; 方涛

    2016-01-01

    Airborne LiDAR technology is introduced briefly .The positioning equation is derived based on the geometrical theory .The errors are analyzed and the error model is built .Through comprehensive analysis and simulated calculation ,the positioning accuracy for LiDAR system is estimated .%介绍机载激光雷达测量技术,根据测量的几何原理推导定位方程。讨论定位的误差来源,建立误差模型并对误差影响进行分析。综合各项因素的影响,将模拟数据代入误差传播公式,计算定位精度。

  4. Aspects of accuracy and precision in the determination of As and Sb in biological materials by neutron activation analysis

    International Nuclear Information System (INIS)

    Aspects of accuracy and precision on the analysis of As and Sb in biological materials using neutron activation with post-irradiation separation are discussed. The separation technique is based on hydride generation. The average yield is over 98% for As and over 95% for Sb, but differences between samples necessitate a yield determination for each sample. Both radiotracers and reactivation have been applied and their practical use for yield correction is discussed. Under optimised conditions, As in NBS SRM 1577A has been analysed to be 45.5 ± 0.7 μg/kg (N = 4), while the Sb-content points to 2.3 ± 1.0 μg/kg (N = 11). 3 figs.; 20 refs.; 5 tabs

  5. Operational Modal Analysis of Wind Turbine Speed-increase Gearbox

    Directory of Open Access Journals (Sweden)

    LI Yafeng

    2013-11-01

    Full Text Available Speed increase transmission gear box is the primary vibration and noise source of wind turbine, Operational modal method was adopted to collect impact data and response data of each point based on the gearbox test model. ANSYS finite element model is established to simulate the wind turbine gearbox. Then the modal frequencies of the two methods were compared to ensure the test model is correct. The results show that operational modal method can be applied in wind turbine gearbox modal analysis and it has important guiding significance to gearbox fault diagnosis and reliability and maintainability improving.  

  6. Contribution of Sample Processing to Variability and Accuracy of the Results of Pesticide Residue Analysis in Plant Commodities.

    Science.gov (United States)

    Ambrus, Árpád; Buczkó, Judit; Hamow, Kamirán Á; Juhász, Viktor; Solymosné Majzik, Etelka; Szemánné Dobrik, Henriett; Szitás, Róbert

    2016-08-10

    Significant reduction of concentration of some pesticide residues and substantial increase of the uncertainty of the results derived from the homogenization of sample materials have been reported in scientific papers long ago. Nevertheless, performance of methods is frequently evaluated on the basis of only recovery tests, which exclude sample processing. We studied the effect of sample processing on accuracy and uncertainty of the measured residue values with lettuce, tomato, and maize grain samples applying mixtures of selected pesticides. The results indicate that the method is simple and robust and applicable in any pesticide residue laboratory. The analytes remaining in the final extract are influenced by their physical-chemical properties, the nature of the sample material, the temperature of comminution of sample, and the mass of test portion extracted. Consequently, validation protocols should include testing the effect of sample processing, and the performance of the complete method should be regularly checked within internal quality control. PMID:26755282

  7. Analysis of the accuracy of the inverse problem solution for a differential heterodyne microscope as applied to rectangular plasmonic waveguides

    Science.gov (United States)

    Akhmedzhanov, I. M.; Baranov, D. V.; Zolotov, E. M.

    2016-06-01

    The existence, uniqueness, and stability of the inverse problem solution for a scanning differential heterodyne microscope as applied to rectangular plasmonic waveguides have been analyzed. The consideration is based on an algorithm using a trial-and-error method that we proposed previously to characterize plasmonic waveguides with a triangular profile. The error of the inverse problem (IP) solution is calculated as dependent on the initial data and with allowance for their errors. Instability domains are found for the IP solution, where the solution error sharply increases. It is shown that the instability domains can be eliminated and the accuracy of the IP solution can be significantly improved in the entire range of initial data by taking initial data in the form of two phase responses of the microscope at different wavelengths.

  8. Increasing biomass resource availability through supply chain analysis

    International Nuclear Information System (INIS)

    Increased inclusion of biomass in energy strategies all over the world means that greater mobilisation of biomass resources will be required to meet demand. Strategies of many EU countries assume the future use of non-EU sourced biomass. An increasing number of studies call for the UK to consider alternative options, principally to better utilise indigenous resources. This research identifies the indigenous biomass resources that demonstrate the greatest promise for the UK bioenergy sector and evaluates the extent that different supply chain drivers influence resource availability. The analysis finds that the UK's resources with greatest primary bioenergy potential are household wastes (>115 TWh by 2050), energy crops (>100 TWh by 2050) and agricultural residues (>80 TWh by 2050). The availability of biomass waste resources was found to demonstrate great promise for the bioenergy sector, although are highly susceptible to influences, most notably by the focus of adopted waste management strategies. Biomass residue resources were found to be the resource category least susceptible to influence, with relatively high near-term availability that is forecast to increase – therefore representing a potentially robust resource for the bioenergy sector. The near-term availability of UK energy crops was found to be much less significant compared to other resource categories. Energy crops represent long-term potential for the bioenergy sector, although achieving higher limits of availability will be dependent on the successful management of key influencing drivers. The research highlights that the availability of indigenous resources is largely influenced by a few key drivers, this contradicting areas of consensus of current UK bioenergy policy. - Highlights: • As global biomass demand increases, focus is placed indigenous resources. • A Biomass Resource Model is applied to analyse UK biomass supply chain dynamics. • Biomass availability is best increased

  9. Analysis of Influence of Terrain Relief Roughness on dem Accuracy Generated from LIDAR in the Czech Republic Territory

    Science.gov (United States)

    Hubacek, M.; Kovarik, V.; Kratochvil, V.

    2016-06-01

    Digital elevation models are today a common part of geographic information systems and derived applications. The way of their creation is varied. It depends on the extent of area, required accuracy, delivery time, financial resources and technologies available. The first model covering the whole territory of the Czech Republic was created already in the early 1980's. Currently, the 5th DEM generation is being finished. Data collection for this model was realized using the airborne laser scanning which allowed creating the DEM of a new generation having the precision up to a decimetre. Model of such a precision expands the possibilities of employing the DEM and it also offers new opportunities for the use of elevation data especially in a domain of modelling the phenomena dependent on highly accurate data. The examples are precise modelling of hydrological phenomena, studying micro-relief objects, modelling the vehicle movement, detecting and describing historical changes of a landscape, designing constructions etc. Due to a nature of the technology used for collecting data and generating DEM, it is assumed that the resulting model achieves lower accuracy in areas covered by vegetation and in built-up areas. Therefore the verification of model accuracy was carried out in five selected areas in Moravia. The network of check points was established using a total station in each area. To determine the reference heights of check points, the known geodetic points whose heights were defined using levelling were used. Up to several thousands of points were surveyed in each area. Individual points were selected according to a different configuration of relief, different surface types, and different vegetation coverage. The sets of deviations were obtained by comparing the DEM 5G heights with reference heights which was followed by verification of tested elevation model. Results of the analysis showed that the model reaches generally higher precision than the declared one in

  10. Improving neutron activation analysis accuracy for the measurement of gold in the characterization of heterogeneous catalysts using a TRIGA reactor

    International Nuclear Information System (INIS)

    To measure the gold content of a catalyst accurately, neutron activation analysis (NAA) is one of the methods of choice. NAA is preferred for such heterogeneous catalysts because: (1) it requires minimal sample preparation; (2) NAA provides consistent and accurate results; and (3) in most cases results are obtained much quicker than competing methods. NAA is also used as a referee for the other elemental techniques when results do not fall within expected statistical uncertainties. However, at very high gold concentrations, applying NAA to determine the gold in a heterogeneous catalyst is more challenging than a routine NAA procedure. On the one hand, the neutron absorption cross section for gold is very high, resulting in significant self-shielding related errors. On the other hand, gold exhibits low energy resonance neutron absorptions. In this application the self-shielding minimization effort was handled more rigorously than the classic suppression of neutron flux within a specimen. This non-routine approach was used because: (1) for most applications, high accuracy, <3 % relative, is desired, (2) the low energy resonances of gold make its neutron reaction rate complex and (3) the TRIGA reactor flux profile used in this study contains both thermal and significant epithermal neutron fluxes. Accuracy and precision, using this new approach, are expected to improve from 15 % to better than 3 % relative uncertainty. This has been accomplished through a rigorous assessment of the observed effects of low energy resonance on the neutron flux spectral shape within the sample and designing an experiment to minimize the effects. (author)

  11. The accuracy of pain drawing in identifying psychological distress in low back pain—systematic review and meta-analysis of diagnostic studies

    OpenAIRE

    Bertozzi, Lucia; Rosso, Anna; Romeo, Antonio; Villafañe, Jorge Hugo; Guccione, Andrew A.; Pillastrini, Paolo; Vanti, Carla

    2015-01-01

    The aim of this systematic review and meta-analysis was to estimate the accuracy of qualitative pain drawings (PDs) in identifying psychological distress in subacute and chronic low back pain (LBP) patients. [Subjects and Methods] Data were obtained from searches of PubMed, EBSCO, Scopus, PsycINFO and ISI Web of Science from their inception to July 2014. Quality assessments of bias and applicability were conducted using the Quality of Diagnostic Accuracy Studies-2 (QUADAS-2). [Results] The su...

  12. Accuracy of non-invasive prenatal testing using cell-free DNA for detection of Down, Edwards and Patau syndromes: a systematic review and meta-analysis

    OpenAIRE

    Taylor-Phillips, Sian; Freeman, Karoline; Geppert, Julia; Agbebiyi, Adeola; Olalekan A Uthman; Madan, Jason; Clarke, Angus; Quenby, Siobhan; Clarke, Aileen

    2016-01-01

    Objective To measure test accuracy of non-invasive prenatal testing (NIPT) for Down, Edwards and Patau syndromes using cell-free fetal DNA and identify factors affecting accuracy. Design Systematic review and meta-analysis of published studies. Data sources PubMed, Ovid Medline, Ovid Embase and the Cochrane Library published from 1997 to 9 February 2015, followed by weekly autoalerts until 1 April 2015. Eligibility criteria for selecting studies English language journal articles describing ca...

  13. Diagnostic accuracy of serum biochemical fibrosis markers in children with chronic hepatitis B evaluated by receiver operating characteristics analysis

    Institute of Scientific and Technical Information of China (English)

    Dariusz Marek Lebensztejn; El(z)bieta Skiba; Jolanta Tobolczyk; Maria El(z)bieta Sobaniec-Lotowska; Maciej Kaczmarski

    2005-01-01

    AIM: To investigate the diagnostic accuracy of potent serum biochemical fibrosis markers in children with chronic hepatitis B evaluated by receiver operating characteristics (ROC) analysis.METHODS: We determined the serum level of apolipoprotein A-I (APO A-I), haptoglobin (HPT) and a-2macroglobulin (A2M) with an automatic nephelometer in 63 children (age range 4-17 years, mean 10 years)with biopsy-verified chronic HBeAg-positive hepatitis B.Fibrosis stage and inflammation grade were assessed in a blinded fashion according to Batts and Ludwig. We defined mild liver fibrosis as a score ≤2 and advanced fibrosis as a score equal to 3. ROC analysis was used to calculate the power of the assays to detect advanced liver fibrosis (AccuROC, Canada).RESULTS: Serum concentrations of APO A-I, HPT and A2M were not significantly different in patients with chronic hepatitis B compared to controls. However, APO A-I level of 1.19 ng/L had a sensitivity of 85.7% and a specificity of 60.7% (AUC = 0.7117, P = 0.035) to predict advanced fibrosis. All other serum biochemical markers and their combination did not allow a useful prediction.None of these markers was a good predictor of histologic inflammation.CONCLUSION: Apolipoprotein A-I may be a suitable serum marker to predict advanced liver fibrosis in children with chronic hepatitis B.

  14. Non-linear partial least square regression increases the estimation accuracy of grass nitrogen and phosphorus using in situ hyperspectral and environmental data

    Science.gov (United States)

    Ramoelo, A.; Skidmore, A. K.; Cho, M. A.; Mathieu, R.; Heitkönig, I. M. A.; Dudeni-Tlhone, N.; Schlerf, M.; Prins, H. H. T.

    2013-08-01

    Grass nitrogen (N) and phosphorus (P) concentrations are direct indicators of rangeland quality and provide imperative information for sound management of wildlife and livestock. It is challenging to estimate grass N and P concentrations using remote sensing in the savanna ecosystems. These areas are diverse and heterogeneous in soil and plant moisture, soil nutrients, grazing pressures, and human activities. The objective of the study is to test the performance of non-linear partial least squares regression (PLSR) for predicting grass N and P concentrations through integrating in situ hyperspectral remote sensing and environmental variables (climatic, edaphic and topographic). Data were collected along a land use gradient in the greater Kruger National Park region. The data consisted of: (i) in situ-measured hyperspectral spectra, (ii) environmental variables and measured grass N and P concentrations. The hyperspectral variables included published starch, N and protein spectral absorption features, red edge position, narrow-band indices such as simple ratio (SR) and normalized difference vegetation index (NDVI). The results of the non-linear PLSR were compared to those of conventional linear PLSR. Using non-linear PLSR, integrating in situ hyperspectral and environmental variables yielded the highest grass N and P estimation accuracy (R2 = 0.81, root mean square error (RMSE) = 0.08, and R2 = 0.80, RMSE = 0.03, respectively) as compared to using remote sensing variables only, and conventional PLSR. The study demonstrates the importance of an integrated modeling approach for estimating grass quality which is a crucial effort towards effective management and planning of protected and communal savanna ecosystems.

  15. SU-F-BRF-14: Increasing the Accuracy of Dose Calculation On Cone-Beam Imaging Using Deformable Image Registration in the Case of Prostate Translation

    Energy Technology Data Exchange (ETDEWEB)

    Fillion, O; Gingras, L [Departement de radiooncologie, CHU de Quebec - Hotel-Dieu de Quebec, Quebec, Quebec (Canada); Departement de physique, de genie physique et d' optique, Universite Laval, Quebec, Quebec (Canada); Archambault, L [Departement de radiooncologie, CHU de Quebec - Hotel-Dieu de Quebec, Quebec, Quebec (Canada); Departement de physique, de genie physique et d' optique, Universite Laval, Quebec, Quebec (Canada); Centre de recherche sur le cancer, Universite Laval, Quebec, Quebec (Canada)

    2014-06-15

    Purpose: Artifacts can reduce the quality of dose re-calculations on CBCT scans during a treatment. The aim of this project is to correct the CBCT images in order to allow for more accurate and exact dose calculations in the case of a translation of the tumor in prostate cancer. Methods: Our approach is to develop strategies based on deformable image registration algorithms using the elastix software (Klein et al., 2010) to register the treatment planning CT on a daily CBCT scan taken during treatment. Sets of images are provided by a 3D deformable phantom and comprise two CT and two CBCT scans: one of both with the reference anatomy and the others with known deformations (i.e. translations of the prostate). The reference CT is registered onto the deformed CBCT and the deformed CT serves as the control for dose calculation accuracy. The planned treatment used for the evaluation of dose calculation is a 2-Gy fraction prescribed at the location of the reference prostate and assigned to 7 rectangular fields. Results: For a realistic 0.5-cm translation of the prostate, the relative dose discrepancy between the CBCT and the CT control scan at the prostate's centroid is 8.9 ± 0.8 % while dose discrepancy between the registered CT and the control scan lessens to −2.4 ± 0.8 %. For a 2-cm translation, clinical indices like the V90 and the D100 are more accurate by 0.7 ± 0.3 % and 8.0 ± 0.5 cGy respectively when using registered CT than when using CBCT for dose calculation. Conclusion: The results show that this strategy gives doses in agreement within a few percents with those from calculations on actual CT scans. In the future, various deformations of the phantom anatomy will allow a thorough characterization of the registration strategies needed for more complex anatomies.

  16. The diagnosis accuracy of PLA2R-AB in the diagnosis of idiopathic membranous nephropathy: a meta-analysis.

    Directory of Open Access Journals (Sweden)

    Yu Du

    Full Text Available BACKGROUND: The presence of antibodies against the M-type phospholipase A2 receptor (PLA2R-AB is considered to be a promising serological diagnostic biomarker of idiopathic membranous nephropathy (iMN. However, controversy remains about the diagnostic accuracy of serum PLA2R-AB testing. Here, we performed a comprehensive meta-analysis to assess the overall diagnostic value of serum PLA2R-AB testing in iMN detection. METHODS: PubMed, Embase, and CNKI (Chinese National Knowledge Infrastructure were searched for relevant original articles through January 31, 2014. The summary sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and diagnostic odds ratio (DOR were estimated using the bivariate model. The heterogeneity among studies was explored by subgroup and meta-regression analysis. RESULTS: 9 articles, including 15 studies, were eventually identified with a total of 2212 patients. The summary sensitivity of all studies is 78% (95% CI: 66% to 87% and the specificity is 99% (95% CI: 96% to 100%. The summary positive and negative likelihood ratios are 96.1 (95% CI, 19.5 to 472.1 and 0.22 (95% CI: 0.14 to 0.35, respectively. The DOR is 437 (95%CI, 74 to 2592. The subgroup analysis and meta-regression suggest the test interval is the main source of heterogeneity. CONCLUSIONS: Serum PLA2R-AB testing is a useful tool to detect iMN. In addition, considering the high heterogeneity and potential publication bias, further high quality studies are needed in the future.

  17. Filtering for increased power for microarray data analysis

    Directory of Open Access Journals (Sweden)

    Hess Ann M

    2009-01-01

    Full Text Available Abstract Background Due to the large number of hypothesis tests performed during the process of routine analysis of microarray data, a multiple testing adjustment is certainly warranted. However, when the number of tests is very large and the proportion of differentially expressed genes is relatively low, the use of a multiple testing adjustment can result in very low power to detect those genes which are truly differentially expressed. Filtering allows for a reduction in the number of tests and a corresponding increase in power. Common filtering methods include filtering by variance, average signal or MAS detection call (for Affymetrix arrays. We study the effects of filtering in combination with the Benjamini-Hochberg method for false discovery rate control and q-value for false discovery rate estimation. Results Three case studies are used to compare three different filtering methods in combination with the two false discovery rate methods and three different preprocessing methods. For the case studies considered, filtering by detection call and variance (on the original scale consistently led to an increase in the number of differentially expressed genes identified. On the other hand, filtering by variance on the log2 scale had a detrimental effect when paired with MAS5 or PLIER preprocessing methods, even when the testing was done on the log2 scale. A simulation study was done to further examine the effect of filtering by variance. We find that filtering by variance leads to higher power, often with a decrease in false discovery rate, when paired with either of the false discovery rate methods considered. This holds regardless of the proportion of genes which are differentially expressed or whether we assume dependence or independence among genes. Conclusion The case studies show that both detection call and variance filtering are viable methods of filtering which can increase the number of differentially expressed genes identified. The

  18. Accuracy and concurrent validity of a sensor-based analysis of sit-to-stand movements in older adults

    NARCIS (Netherlands)

    Regterschot, G. Ruben H.; Zhang, Wei; Baldus, Heribert; Stevens, Martin; Zijlstra, Wiebren

    2016-01-01

    Body-fixed motion sensors have been applied for the assessment of sit-to-stand (STS) performance. However, the accuracy and concurrent validity of sensor-based estimations of the body's center of mass (CoM) motion during STS are unclear. Therefore, this study investigated the accuracy and concurrent

  19. Diagnostic test accuracy of D-dimer for acute aortic syndrome: systematic review and meta-analysis of 22 studies with 5000 subjects

    Science.gov (United States)

    Watanabe, Hiroki; Horita, Nobuyuki; Shibata, Yuji; Minegishi, Shintaro; Ota, Erika; Kaneko, Takeshi

    2016-01-01

    Diagnostic test accuracy of D-dimer for acute aortic dissection (AAD) has not been evaluated by meta-analysis with the bivariate model methodology. Four databases were electrically searched. We included both case-control and cohort studies that could provide sufficient data concerning both sensitivity and specificity of D-dimer for AAD. Non-English language articles and conference abstract were allowed. Intramural hematoma and penetrating aortic ulcer were regarded as AAD. Based on 22 eligible articles consisting of 1140 AAD subjects and 3860 non-AAD subjects, the diagnostic odds ratio was 28.5 (95% CI 17.6–46.3, I2 = 17.4%) and the area under curve was 0.946 (95% CI 0.903–0.994). Based on 833 AAD subjects and 1994 non-AAD subjects constituting 12 studies that used the cutoff value of 500 ng/ml, the sensitivity was 0.952 (95% CI 0.901–0.978), the specificity was 0.604 (95% CI 0.485–0.712), positive likelihood ratio was 2.4 (95% CI 1.8–3.3), and negative likelihood ratio was 0.079 (95% CI 0.036–0.172). Sensitivity analysis using data of three high-quality studies almost replicated these results. In conclusion, D-dimer has very good overall accuracy. D-dimer 500 ng/ml moderately increases the possibility of AAD. PMID:27230962

  20. Estimating subsurface water volumes and transit times in Hokkaido river catchments, Japan, using high-accuracy tritium analysis

    Science.gov (United States)

    Gusyev, Maksym; Yamazaki, Yusuke; Morgenstern, Uwe; Stewart, Mike; Kashiwaya, Kazuhisa; Hirai, Yasuyuki; Kuribayashi, Daisuke; Sawano, Hisaya

    2015-04-01

    The goal of this study is to estimate subsurface water transit times and volumes in headwater catchments of Hokkaido, Japan, using the New Zealand high-accuracy tritium analysis technique. Transit time provides insights into the subsurface water storage and therefore provides a robust and quick approach to quantifying the subsurface groundwater volume. Our method is based on tritium measurements in river water. Tritium is a component of meteoric water, decays with a half-life of 12.32 years, and is inert in the subsurface after the water enters the groundwater system. Therefore, tritium is ideally suited for characterization of the catchment's responses and can provide information on mean water transit times up to 200 years. Only in recent years has it become possible to use tritium for dating of stream and river water, due to the fading impact of the bomb-tritium from thermo-nuclear weapons testing, and due to improved measurement accuracy for the extremely low natural tritium concentrations. Transit time of the water discharge is one of the most crucial parameters for understanding the response of catchments and estimating subsurface water volume. While many tritium transit time studies have been conducted in New Zealand, only a limited number of tritium studies have been conducted in Japan. In addition, the meteorological, orographic and geological conditions of Hokkaido Island are similar to those in parts of New Zealand, allowing for comparison between these regions. In 2014, three field trips were conducted in Hokkaido in June, July and October to sample river water at river gauging stations operated by the Ministry of Land, Infrastructure, Transport and Tourism (MLIT). These stations have altitudes between 36 m and 860 m MSL and drainage areas between 45 and 377 km2. Each sampled point is located upstream of MLIT dams, with hourly measurements of precipitation and river water levels enabling us to distinguish between the snow melt and baseflow contributions

  1. The Accuracy of Conformation of a Generic Surface Mesh for the Analysis of Facial Soft Tissue Changes

    Science.gov (United States)

    Cheung, Man Yan; Almukhtar, Anas; Keeling, Andrew; Hsung, Tai-Chiu; Ju, Xiangyang; McDonald, James; Ayoub, Ashraf; Khambay, Balvinder Singh

    2016-01-01

    Purpose Three dimensional analysis of the face is required for the assessment of complex changes following surgery, pathological conditions and to monitor facial growth. The most suitable method may be “dense surface correspondence”. Materials and Methods This method utilizes a generic facial mesh and “conformation process” to establish anatomical correspondences between two facial images. The aim of this study was to validate the use of conformed meshes to measure simulated maxillary and mandibular surgical movements. The “simulation” was performed by deforming the actual soft tissues of the participant during image acquisition. The study was conducted on 20 volunteers and used 77 facial landmarks pre-marked over six anatomical regions; left cheek, right cheek, left upper lip, philtrum, right upper lip and chin region. Each volunteer was imaged at rest and after performing 5 different simulated surgical procedures using 3D stereophotogrammetry. The simulated surgical movement was determined by measuring the Euclidean distances and the mean absolute x, y and z distances of the landmarks making up the six regions following digitization. A generic mesh was then conformed to each of the aligned six facial 3D images. The same six regions were selected on the aligned conformed simulated meshes and the surgical movement determined by determining the Euclidean distances and the mean absolute x, y and z distances of the mesh points making up the six regions were determined. Results In all cases the mean Euclidian distance between the simulated movement and conformed region was less than 0.7mm. For the x, y and z directions the majority of differences in the mean absolute distances were less than 1.0mm except in the x-direction for the left and right cheek regions, which was above 2.0mm. Conclusions This concludes that the conformation process has an acceptable level of accuracy and is a valid method of measuring facial change between two images i.e. pre- and

  2. GALA: Group Analysis Leads to Accuracy, a novel approach for solving the inverse problem in exploratory analysis of group MEG recordings

    Directory of Open Access Journals (Sweden)

    Vladimir eKozunov

    2015-04-01

    Full Text Available Although MEG/EEG signals are highly variable between subjects, they allow characterizing systematic changes of cortical activity in both space and time. Traditionally a two-step procedure is used. The first step is a transition from sensor to source space by the means of solving an ill-posed inverse problem for each subject individually. The second is mapping of cortical regions consistently active across subjects. In practice the first step often leads to a set of active cortical regions whose location and timecourses display a great amount of interindividual variability hindering the subsequent group analysis.We propose Group Analysis Leads to Accuracy (GALA - a solution that combines the two steps into one. GALA takes advantage of individual variations of cortical geometry and sensor locations. It exploits the ensuing variability in electromagnetic forward model as a source of additional information. We assume that for different subjects functionally identical cortical regions are located in close proximity and partially overlap and their timecourses are correlated. This relaxed similarity constraint on the inverse solution can be expressed within a probabilistic framework, allowing for an iterative algorithm solving the inverse problem jointly for all subjects.A systematic simulation study showed that GALA, as compared with the standard min-norm approach, improves accuracy of true activity recovery, when accuracy is assessed both in terms of spatial proximity of the estimated and true activations and correct specification of spatial extent of the activated regions. This improvement obtained without using any noise normalization techniques for both solutions, preserved for a wide range of between-subject variations in both spatial and temporal features of regional activation. The corresponding activation timecourses exhibit significantly higher similarity across subjects. Similar results were obtained for a real MEG dataset of face

  3. Increase of the fuel cell system efficiency - Modular testing, analysis and development environment

    Science.gov (United States)

    König, P.; Ivers-Tiffée, E.

    The main issue in preparing fuel cell systems for the future market is system reliability and efficiency. Apart from successful field test trials, any type of stationary, in general automotive or portable fuel cell systems are at the development stage. One task to deal with is to increase the component and system efficiencies by facilitating the system construction or eliminating parasitic components.With newly established effective standardised system and component tests, linked with a flexible modelling and simulation environment, the development process and the determination of the system efficiencies as well as the inaccessible system values can be accelerated.In this work a modular model-aided system analysis and development environment is presented which has been evaluated and validated at the IWE. The tool, a combination of standardised testing, modelling and simulation, has been applied to different types of fuel cell systems showing the tool flexibility, modularity and accuracy. In the presented case the tool was used for system analysis and studies on efficiency increase of a complex prototype stationary PEMFC system.

  4. Accuracy of sampling during mushroom cultivation

    OpenAIRE

    Baars, J.J.P.; Hendrickx, P.M.; Sonnenberg, A.S.M.

    2015-01-01

    Experiments described in this report were performed to increase the accuracy of the analysis of the biological efficiency of Agaricus bisporus strains. Biological efficiency is a measure of the efficiency with which the mushroom strains use dry matter in the compost to produce mushrooms (expressed as dry matter produced).

  5. The regulatory benefits of high levels of affect perception accuracy: a process analysis of reactions to stressors in daily life.

    Science.gov (United States)

    Robinson, Michael D; Moeller, Sara K; Buchholz, Maria M; Boyd, Ryan L; Troop-Gordon, Wendy

    2012-08-01

    Individuals attuned to affective signals from the environment may possess an advantage in the emotion-regulation realm. In two studies (total n = 151), individual differences in affective perception accuracy were assessed in an objective, performance-based manner. Subsequently, the same individuals completed daily diary protocols in which daily stressor levels were reported as well as problematic states shown to be stress-reactive in previous studies. In both studies, individual differences in affect perception accuracy interacted with daily stressor levels to predict the problematic outcomes. Daily stressors precipitated problematic reactions--whether depressive feelings (study 1) or somatic symptoms (study 2)--at low levels of affect perception accuracy, but did not do so at high levels of affect perception accuracy. The findings support a regulatory view of such perceptual abilities. Implications for understanding emotion regulation processes, emotional intelligence, and individual differences in reactivity are discussed. PMID:22775136

  6. Performance-Based Cognitive Screening Instruments: An Extended Analysis of the Time versus Accuracy Trade-off

    OpenAIRE

    Larner, Andrew J

    2015-01-01

    Early and accurate diagnosis of dementia is key to appropriate treatment and management. Clinical assessment, including the use of cognitive screening instruments, remains integral to the diagnostic process. Many cognitive screening instruments have been described, varying in length and hence administration time, but it is not known whether longer tests offer greater diagnostic accuracy than shorter tests. Data from several pragmatic diagnostic test accuracy studies examining various cognitiv...

  7. Accuracy of bronchoalveolar lavage enzyme-linked immunospot assay to diagnose smear-negative tuberculosis: a meta-analysis

    OpenAIRE

    Li, Zhenzhen; Qin, Wenzhe; Li, Lei; WU, QIN; Chen, Xuerong

    2015-01-01

    Purpose: While the bronchoalveolar lavage enzyme-linked immunospot assay (BAL-ELISPOT) shows promise for diagnosing smear-negative tuberculosis, its accuracy remains controversial. We meta-analyzed the available evidence to obtain a clearer understanding of the diagnostic accuracy. Methods: Studies of the diagnostic performance of ELI-SPOT on smear-negative tuberculosis were identified through systematic searches of the PubMed and EMBASE databases. Pooled data on sensitivity, specificity and ...

  8. Increasing the accuracy of {sup 18}F-FDG PET/CT interpretation of “mildly positive” mediastinal nodes in the staging of non-small cell lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Moloney, F., E-mail: fiachramoloney@hotmail.com [Department of Radiology, Cork University Hospital, Cork - 00353214922000 (Ireland); Ryan, D., E-mail: ryansurgeon@gmail.com [Department of Radiology, Cork University Hospital, Cork - 00353214922000 (Ireland); McCarthy, L., E-mail: lauraghmccarthy1@hotmail.com [Department of Radiology, Cork University Hospital, Cork - 00353214922000 (Ireland); McCarthy, J., E-mail: julie.mccarthy@hse.ie [Department of Pathology, Cork University Hospital, Cork - 0214922000 (Ireland); Burke, L., E-mail: louise.burke@hse.ie [Department of Pathology, Cork University Hospital, Cork - 0214922000 (Ireland); Henry, M.T., E-mail: michael.henry@hse.ie [Department of Respiratory Medicine, Cork University Hospital, Cork - 00353214922000 (Ireland); Kennedy, M.P., E-mail: marcus.kennedy@hse.ie [Department of Respiratory Medicine, Cork University Hospital, Cork - 00353214922000 (Ireland); Hinchion, J., E-mail: John.Hinchion@hse.ie [Department of Cardiothoracic Surgery, Cork University Hospital, Cork - 00353214922000 (Ireland); McSweeney, S., E-mail: Sean.McSweeny@hse.ie [Department of Radiology, Cork University Hospital, Cork - 00353214922000 (Ireland); Maher, M.M., E-mail: m.maher@ucc.ie [Department of Radiology, Cork University Hospital, Cork - 00353214922000 (Ireland); O’Regan, K., E-mail: kevin.ORegan1@hse.ie [Department of Radiology, Cork University Hospital, Cork - 00353214922000 (Ireland)

    2014-05-15

    Introduction: The aim of this study was to identify radiological factors that may reduce false-positive results and increase diagnostic accuracy when staging the mediastinum of patients with non-small cell lung carcinoma (NSCLC). Methods: This was a retrospective, interdisciplinary, per-node analysis study. We included patients with NSCLC and mediastinal nodes with an SUV max in the range of 2.5–4.0 on PET-CT. We hypothesized that the greatest number of false positive cases would occur in this cohort of patients. Results: A total of 92 mediastinal lymph nodes were analyzed in 44 patients. Mediastinal disease (N2/N3) was histologically confirmed in 15 of 44 patients and in 34 of 92 lymph nodes; positive predictive value of 37% and false positive rate of 63%. Lymph node SUV max, tumor size, ratio of node SUV max to tumor SUV max (SUVn/SUVp), and ratio of node SUV max to node size (SUV n/SADn) were significantly higher in true positive cases. Using a threshold of 0.3 for SUV node/tumor and 3 for SUV node/size yielded sensitivities of 91% and 71% and specificities of 71% and 69% respectively for the detection of mediastinal disease. Using both ratios in combination resulted in a sensitivity of 65% and a specificity of 88%. Concurrent benign lung disease was observed significantly more frequently in false-positive cases. Conclusion: SUVn/SUVpt and SUVn/SADn may be complimentary to conventional visual interpretation and SUV max measurement in the assessment of mediastinal disease in patients with NSCLC.

  9. Development of response models for the Earth Radiation Budget Experiment (ERBE) sensors. Part 3: ERBE scanner measurement accuracy analysis due to reduced housekeeping data

    Science.gov (United States)

    Choi, Sang H.; Chrisman, Dan A., Jr.; Halyo, Nesim

    1987-01-01

    The accuracy of scanner measurements was evaluated when the sampling frequency of sensor housekeeping (HK) data was reduced from once every scan to once every eight scans. The resulting increase in uncertainty was greatest for sources with rapid or extreme temperature changes. This analysis focused on the mirror attenuator mosaic (MAM) baffle and plate and scanner radiometer baffle due to their relatively high temperature changes during solar calibrations. Since only solar simulator data were available, the solar temperatures were approximated on these components and the radiative and thermal gradients in the MAM baffle due to reflected sunlight. Of the two cases considered for the MAM plate and baffle temperatures, one uses temperatures obtained from the ground calibration. The other attempt uses temperatures computed from the MAM baffle model. This analysis shows that the heat input variations due largely to the solar radiance and irradiance during a scan cycle are small. It also demonstrates that reasonable intervals longer than the current HK data acquisition interval should not significantly affect the estimation of a radiation field in the sensor field-of-view.

  10. A novel computer-assisted image analysis of [{sup 123}I]{beta}-CIT SPECT images improves the diagnostic accuracy of parkinsonian disorders

    Energy Technology Data Exchange (ETDEWEB)

    Goebel, Georg [Innsbruck Medical University, Department of Medical Statistics, Informatics and Health Economics, Innsbruck (Austria); Seppi, Klaus; Wenning, Gregor K.; Poewe, Werner; Scherfler, Christoph [Innsbruck Medical University, Department of Neurology, Innsbruck (Austria); Donnemiller, Eveline; Warwitz, Boris; Virgolini, Irene [Innsbruck Medical University, Department of Nuclear Medicine, Innsbruck (Austria)

    2011-04-15

    The purpose of this study was to develop an observer-independent algorithm for the correct classification of dopamine transporter SPECT images as Parkinson's disease (PD), multiple system atrophy parkinson variant (MSA-P), progressive supranuclear palsy (PSP) or normal. A total of 60 subjects with clinically probable PD (n = 15), MSA-P (n = 15) and PSP (n = 15), and 15 age-matched healthy volunteers, were studied with the dopamine transporter ligand [{sup 123}I]{beta}-CIT. Parametric images of the specific-to-nondisplaceable equilibrium partition coefficient (BP{sub ND}) were generated. Following a voxel-wise ANOVA, cut-off values were calculated from the voxel values of the resulting six post-hoc t-test maps. The percentages of the volume of an individual BP{sub ND} image remaining below and above the cut-off values were determined. The higher percentage of image volume from all six cut-off matrices was used to classify an individual's image. For validation, the algorithm was compared to a conventional region of interest analysis. The predictive diagnostic accuracy of the algorithm in the correct assignment of a [{sup 123}I]{beta}-CIT SPECT image was 83.3% and increased to 93.3% on merging the MSA-P and PSP groups. In contrast the multinomial logistic regression of mean region of interest values of the caudate, putamen and midbrain revealed a diagnostic accuracy of 71.7%. In contrast to a rater-driven approach, this novel method was superior in classifying [{sup 123}I]{beta}-CIT-SPECT images as one of four diagnostic entities. In combination with the investigator-driven visual assessment of SPECT images, this clinical decision support tool would help to improve the diagnostic yield of [{sup 123}I]{beta}-CIT SPECT in patients presenting with parkinsonism at their initial visit. (orig.)

  11. High accuracy mass spectrometry analysis as a tool to verify and improve gene annotation using Mycobacterium tuberculosis as an example

    Directory of Open Access Journals (Sweden)

    Prasad Swati

    2008-07-01

    Full Text Available Abstract Background While the genomic annotations of diverse lineages of the Mycobacterium tuberculosis complex are available, divergences between gene prediction methods are still a challenge for unbiased protein dataset generation. M. tuberculosis gene annotation is an example, where the most used datasets from two independent institutions (Sanger Institute and Institute of Genomic Research-TIGR differ up to 12% in the number of annotated open reading frames, and 46% of the genes contained in both annotations have different start codons. Such differences emphasize the importance of the identification of the sequence of protein products to validate each gene annotation including its sequence coding area. Results With this objective, we submitted a culture filtrate sample from M. tuberculosis to a high-accuracy LTQ-Orbitrap mass spectrometer analysis and applied refined N-terminal prediction to perform comparison of two gene annotations. From a total of 449 proteins identified from the MS data, we validated 35 tryptic peptides that were specific to one of the two datasets, representing 24 different proteins. From those, 5 proteins were only annotated in the Sanger database. In the remaining proteins, the observed differences were due to differences in annotation of transcriptional start sites. Conclusion Our results indicate that, even in a less complex sample likely to represent only 10% of the bacterial proteome, we were still able to detect major differences between different gene annotation approaches. This gives hope that high-throughput proteomics techniques can be used to improve and validate gene annotations, and in particular for verification of high-throughput, automatic gene annotations.

  12. A meta-analysis of the diagnostic accuracy of dengue virus-specific IgA antibody-based tests for detection of dengue infection.

    Science.gov (United States)

    Alagarasu, K; Walimbe, A M; Jadhav, S M; Deoshatwar, A R

    2016-03-01

    Immunoglobulin A (IgA)-based tests have been evaluated in different studies for their utility in diagnosing dengue infections. In most of the studies, the results were inconclusive because of a small sample size. Hence, a meta-analysis involving nine studies with 2096 samples was performed to assess the diagnostic accuracy of IgA-based tests in diagnosing dengue infections. The analysis was conducted using Meta-Disc software. The results revealed that IgA-based tests had an overall sensitivity, specificity, diagnostic odds ratio, and positive and negative likelihood ratios of 73·9%, 95·2%, 66·7, 22·0 and 0·25, respectively. Significant heterogeneity was observed between the studies. The type of test, infection status and day of sample collection influenced the diagnostic accuracy. The IgA-based diagnostic tests showed a greater accuracy when the samples were collected 4 days after onset of symptoms and for secondary infections. The results suggested that IgA-based tests had a moderate level of accuracy and are diagnostic of the disease. However, negative results cannot be used alone for dengue diagnosis. More prospective studies comparing the diagnostic accuracy of combinations of antigen-based tests with either IgA or IgM are needed and might be useful for suggesting the best strategy for dengue diagnosis.

  13. MR Thermometry Analysis of Sonication Accuracy and Safety Margin of Volumetric MR Imaging-guided High-Intensity Focused Ultrasound Ablation of Symptomatic Uterine Fibroids

    NARCIS (Netherlands)

    Kim, Young-sun; Trillaud, Herve; Rhim, Hyunchul; Lim, Hyo K.; Mali, Willem; Voogt, Marianne; Barkhausen, Jorg; Eckey, Thomas; Kohler, Max O.; Keserci, Bilgin; Mougenot, Charles; Sokka, Shunmugavelu D.; Soini, Jouko; Nieminen, Heikki J.

    2012-01-01

    Purpose: To evaluate the accuracy of the size and location of the ablation zone produced by volumetric magnetic resonance (MR) imaging-guided high-intensity focused ultrasound ablation of uterine fibroids on the basis of MR thermometric analysis and to assess the effects of a feedback control techni

  14. Performance-Based Cognitive Screening Instruments: An Extended Analysis of the Time versus Accuracy Trade-off

    Directory of Open Access Journals (Sweden)

    Andrew J. Larner

    2015-11-01

    Full Text Available Early and accurate diagnosis of dementia is key to appropriate treatment and management. Clinical assessment, including the use of cognitive screening instruments, remains integral to the diagnostic process. Many cognitive screening instruments have been described, varying in length and hence administration time, but it is not known whether longer tests offer greater diagnostic accuracy than shorter tests. Data from several pragmatic diagnostic test accuracy studies examining various cognitive screening instruments in a secondary care setting were analysed to correlate measures of test diagnostic accuracy and test duration, building on the findings of a preliminary study. High correlations which were statistically significant were found between one measure of diagnostic accuracy, area under the receiver operating characteristic curve, and surrogate measures of test duration, namely total test score and total number of test items/questions. Longer cognitive screening instruments may offer greater accuracy for the diagnosis of dementia, an observation which has possible implications for the optimal organisation of dedicated cognitive disorders clinics.

  15. Diagnostic test accuracy of anti-glycopeptidolipid-core IgA antibodies for Mycobacterium avium complex pulmonary disease: systematic review and meta-analysis

    OpenAIRE

    Yuji Shibata; Nobuyuki Horita; Masaki Yamamoto; Toshinori Tsukahara; Hideyuki Nagakura; Ken Tashiro; Hiroki Watanabe; Kenjiro Nagai; Kentaro Nakashima; Ryota Ushio; Misako Ikeda; Atsuya Narita; Akinori Kanai; Takashi Sato; Takeshi Kaneko

    2016-01-01

    Currently, an anti-glycopeptidolipid (GPL)-core IgA antibody assay kit for diagnosing Mycobacterium avium complex (MAC) is commercially available. We conducted this systematic review and meta-analysis to reveal the precise diagnostic accuracy of anti-GPL-core IgA antibodies for MAC pulmonary disease (MAC-PD). We systematically searched reports that could provide data for both sensitivity and specificity by anti-GPL-core IgA antibody for clinically diagnosed MAC-PD. Diagnostic test accuracy wa...

  16. Spontaneous Subarachnoid Hemorrhage: A Systematic Review and Meta-Analysis Describing the Diagnostic Accuracy of History, Physical Exam, Imaging, and Lumbar Puncture with an Exploration of Test Thresholds

    Science.gov (United States)

    Carpenter, Christopher R.; Hussain, Adnan M.; Ward, Michael J.; Zipfel, Gregory J.; Fowler, Susan; Pines, Jesse M.; Sivilotti, Marco L.A.

    2016-01-01

    Background Spontaneous subarachnoid hemorrhage (SAH) is a rare, but serious etiology of headache. The diagnosis of SAH is especially challenging in alert, neurologically intact patients, as missed or delayed diagnosis can be catastrophic. Objectives To perform a diagnostic accuracy systematic review and meta-analysis of history, physical examination, cerebrospinal fluid (CSF) tests, computed tomography (CT), and clinical decision rules for spontaneous SAH. A secondary objective was to delineate probability of disease thresholds for imaging and lumbar puncture (LP). Methods PUBMED, EMBASE, SCOPUS, and research meeting abstracts were searched up to June 2015 for studies of emergency department (ED) patients with acute headache clinically concerning for spontaneous SAH. QUADAS-2 was used to assess study quality and, when appropriate, meta-analysis was conducted using random effects models. Outcomes were sensitivity, specificity, positive (LR+) and negative (LR−) likelihood ratios. To identify test- and treatment-thresholds, we employed the Pauker-Kassirer method with Bernstein test-indication curves using the summary estimates of diagnostic accuracy. Results A total of 5,022 publications were identified, of which 122 underwent full text-review; 22 studies were included (average SAH prevalence 7.5%). Diagnostic studies differed in assessment of history and physical exam findings, CT technology, analytical techniques used to identify xanthochromia, and criterion standards for SAH. Study quality by QUADAS-2 was variable; however, most had a relatively low-risk of biases. A history of neck pain (LR+ 4.1 [95% CI 2.2-7.6]) and neck stiffness on physical exam (LR+ 6.6 [4.0-11.0]) were the individual findings most strongly associated with SAH. Combinations of findings may rule out SAH, yet promising clinical decision rules await external validation. Non-contrast cranial CT within 6 hours of headache onset accurately ruled-in (LR+ 230 [6-8700]) and ruled-out SAH (LR− 0

  17. Diagnostic accuracy of refractometer and Brix refractometer to assess failure of passive transfer in calves: protocol for a systematic review and meta-analysis.

    Science.gov (United States)

    Buczinski, S; Fecteau, G; Chigerwe, M; Vandeweerd, J M

    2016-06-01

    Calves are highly dependent of colostrum (and antibody) intake because they are born agammaglobulinemic. The transfer of passive immunity in calves can be assessed directly by dosing immunoglobulin G (IgG) or by refractometry or Brix refractometry. The latter are easier to perform routinely in the field. This paper presents a protocol for a systematic review meta-analysis to assess the diagnostic accuracy of refractometry or Brix refractometry versus dosage of IgG as a reference standard test. With this review protocol we aim to be able to report refractometer and Brix refractometer accuracy in terms of sensitivity and specificity as well as to quantify the impact of any study characteristic on test accuracy. PMID:27427188

  18. The influence of multivariate analysis methods and target grain size on the accuracy of remote quantitative chemical analysis of rocks using laser induced breakdown spectroscopy

    Science.gov (United States)

    Anderson, Ryan B.; Morris, Richard V.; Clegg, Samuel M.; Bell, James F.; Wiens, Roger C.; Humphries, Seth D.; Mertzman, Stanley A.; Graff, Trevor G.; McInroy, Rhonda

    2011-10-01

    resulting in lower accuracy and precision than analyses of fine-grained rocks and powders. The number of analysis spots that were normally required to produce a chemical analysis within one standard deviation of the true bulk composition ranged from ˜10 for fine-grained rocks to >20 for some coarse-grained rocks.

  19. Development of Automated Image Analysis Tools for Verification of Radiotherapy Field Accuracy with AN Electronic Portal Imaging Device.

    Science.gov (United States)

    Dong, Lei

    1995-01-01

    The successful management of cancer with radiation relies on the accurate deposition of a prescribed dose to a prescribed anatomical volume within the patient. Treatment set-up errors are inevitable because the alignment of field shaping devices with the patient must be repeated daily up to eighty times during the course of a fractionated radiotherapy treatment. With the invention of electronic portal imaging devices (EPIDs), patient's portal images can be visualized daily in real-time after only a small fraction of the radiation dose has been delivered to each treatment field. However, the accuracy of human visual evaluation of low-contrast portal images has been found to be inadequate. The goal of this research is to develop automated image analysis tools to detect both treatment field shape errors and patient anatomy placement errors with an EPID. A moments method has been developed to align treatment field images to compensate for lack of repositioning precision of the image detector. A figure of merit has also been established to verify the shape and rotation of the treatment fields. Following proper alignment of treatment field boundaries, a cross-correlation method has been developed to detect shifts of the patient's anatomy relative to the treatment field boundary. Phantom studies showed that the moments method aligned the radiation fields to within 0.5mm of translation and 0.5^ circ of rotation and that the cross-correlation method aligned anatomical structures inside the radiation field to within 1 mm of translation and 1^ circ of rotation. A new procedure of generating and using digitally reconstructed radiographs (DRRs) at megavoltage energies as reference images was also investigated. The procedure allowed a direct comparison between a designed treatment portal and the actual patient setup positions detected by an EPID. Phantom studies confirmed the feasibility of the methodology. Both the moments method and the cross -correlation technique were

  20. Accuracy of diagnostic ultrasound in patients with suspected subacromial disorders: a systematic review and meta-analysis.

    NARCIS (Netherlands)

    Ottenheijm, R.P.; Jansen, M.J.; Staal, J.B.; Bruel, A. van den; Weijers, R.E.; Bie, R.A. de; Dinant, G.J.

    2010-01-01

    OBJECTIVE: To determine the diagnostic accuracy of ultrasound for detecting subacromial disorders in patients presenting in primary and secondary care settings. DATA SOURCES: Medline and Embase were searched on June 9, 2010. In addition, the reference list of 1 systematic review and all included art

  1. The accuracy of physical diagnostic tests for assessing meniscal lesions of the knee: a meta-analysis.

    NARCIS (Netherlands)

    Scholten, R.J.P.M.; Devillé, W.L.J.M.; Opstelten, W.; Bijl, D.; Plas, C.G. van der; Bouter, L.M.

    2001-01-01

    OBJECTIVE. Our systematic review summarizes the evidence about the accuracy of physical diagnostic tests for assessing meniscal lesions of the knee. SEARCH STRATEGY. We performed a literature search of MEDLINE (1966-1999) and EMBASE 1988- 1999) with additional reference tracking. SELECTION CRITERIA

  2. Estimation Model and Accuracy Analysis of BeiDou/GPS Real-time Precise Satellite Clock Error Integrated Resolving

    Directory of Open Access Journals (Sweden)

    CHEN Liang

    2016-09-01

    Full Text Available Real-time high-precise satellite orbit and clock products are needed in real-time GNSS precise point positioning (PPP. In this paper, Estimation model and strategy of multi-GNSS precise satellite clock integrated resolving are researched and BeiDou/GPS real-time precise clock integrated estimation algorithm is realized by filter. Real-time simulation test results show: the STD accuracy of BeiDou/GPS real-time clock estimated in this paper compared to GFZ multi-GNSS precise clock(GBM is about 0.15ns; horizontal accuracy after convergence of GPS kinematic PPP using simulation real-time clock products estimated in this paper is better than 5cm and vertical accuracy is better than 10cm, respectively; in BeiDou kinematic PPP test, horizontal and vertical accuracy results are same as the results using GFZ multi-GNSS precise clock(GBM products, and the decimeter positioning can be realized.

  3. Increased Accuracy in Statistical Seasonal Hurricane Forecasting

    Science.gov (United States)

    Nateghi, R.; Quiring, S. M.; Guikema, S. D.

    2012-12-01

    Hurricanes are among the costliest and most destructive natural hazards in the U.S. Accurate hurricane forecasts are crucial to optimal preparedness and mitigation decisions in the U.S. where 50 percent of the population lives within 50 miles of the coast. We developed a flexible statistical approach to forecast annual number of hurricanes in the Atlantic region during the hurricane season. Our model is based on the method of Random Forest and captures the complex relationship between hurricane activity and climatic conditions through careful variable selection, model testing and validation. We used the National Hurricane Center's Best Track hurricane data from 1949-2011 and sixty-one candidate climate descriptors to develop our model. The model includes information prior to the hurricane season, i.e., from the last three months of the previous year (Oct. through Dec.) and the first five months of the current year (January through May). Our forecast errors are substantially lower than other leading forecasts such as that of the National Oceanic and Atmospheric Administration (NOAA).

  4. An analysis of increasing price of gricultural products

    Institute of Scientific and Technical Information of China (English)

    王豪; 周婷婷

    2008-01-01

    @@ This report consists of following sections:at first,this report will show the content and source of the cited article,the topic of which is that price hikes for meat,eggs to affect CPI in china;Second,this part mostly presents some theories of economics which are related to the price;Third,through economic analysis,this part search for the method that solve the problem;At last,we will get the conclusion.

  5. High-resolution Fourier transform ion cyclotron resonance mass spectrometry with increased throughput for biomolecular analysis.

    Science.gov (United States)

    Nagornov, Konstantin O; Gorshkov, Mikhail V; Kozhinov, Anton N; Tsybin, Yury O

    2014-09-16

    A multielectrode ion cyclotron resonance (ICR) cell, herein referred to as the "4X cell", for signal detection at the quadruple frequency multiple was implemented and characterized on a commercial 10 T Fourier transform ICR mass spectrometer (FT-ICR MS). Notably, with the 4X cell operating at a 10 T magnetic field we achieved a 4-fold increase in MS acquisition rate per unit of resolving power for signal detection periods typically employed in FTMS, viz., shorter than 6 s. Effectively, the obtained resolution performance represents the limit of the standard measurement principle with dipolar signal detection and FT signal processing at an equivalent magnetic field of 40 T. In other words, the achieved resolving powers are 4 times higher than those provided by 10 T FT-ICR MS with a standard ICR cell. For example, resolving powers of 170,000 and 70,000 were obtained in magnitude-mode Fourier spectra of 768 and 192 ms apodized transient signals acquired for a singly charged fluorinated phosphazine (m/z 1422) and a 19-fold charged myoglobin (MW 16.9 kDa), respectively. In peptide analysis, the baseline-resolved isotopic fine structures were obtained with as short as 768 ms transients. In intact protein analysis, the average resolving power of 340,000 across the baseline-resolved (13)C isotopic pattern of multiply charged ions of bovine serum albumin was obtained with 1.5 s transients. The dynamic range and the mass measurement accuracy of the 4X cell were found to be comparable to the ones obtained for the standard ICR cell on the same mass spectrometer. Overall, the reported results validate the advantages of signal detection at frequency multiples for increased throughput in FT-ICR MS, essential for numerous applications with time constraints, including proteomics.

  6. The analysis of the accuracy of the wheel alignment inspection method on the side-slip plate stand

    Science.gov (United States)

    Gajek, A.; Strzępek, P.

    2016-09-01

    The article presents the theoretical basis and the results of the examination of the wheel alignment inspection method on the slide slip plate stand. It is obligatory test during periodic technical inspection of the vehicle. The measurement is executed in the dynamic conditions. The dependence between the lateral displacement of the plate and toe-in of the tested wheels has been shown. If the diameter of the wheel rim is known then the value of the toe-in can be calculated. The comparison of the toe-in measurements on the plate stand and on the four heads device for the wheel alignment inspection has been carried out. The accuracy of the measurements and the influence of the conditions of the tests on the plate stand (the way of passing through the plate) were estimated. The conclusions about the accuracy of this method are presented.

  7. Comparative analysis ex vivo of the accuracy of three apex locators: Root ZX, Bingo 1020 and Ipex

    Directory of Open Access Journals (Sweden)

    Roberta HEIDEMANN

    2009-03-01

    Full Text Available Introduction and objective: The objective of this study was to evaluate ex vivo the reading accuracy of three electronic apex locators – Root ZX, Bingo 1020 and Ipex –, in respect to the real measure of the teeth.Material and methods: Fifty single root premolar teeth extracted were selected. After coronary access, the length tooth (LT measurement was directly realized by the insertion of a K#10 file in the canal until its tip was observed in the apical foramen with the help of a magnifying glass (8X. After removing the file, its length was recorded with accuracy of 0.01 mm using digital caliper. Then, the teeth were electronically measured (LE whit the three apex locators until achieving the zero mark on the display of each unit. The electronically measures obtained were compared with the LT and the differences were analyzed by the Kruskal-Wallis Test and by the test of proportions (α = 0.05. Results: It was found that the Root ZX system was statistically different from the Ipex (p 0.05. Within the limit of tolerance of ± 1.0 mm, the results demonstrated an accuracy of 100% for ZX Root, 94% for Bingo and 90% for Ipex when compared to the LT values. However, in the limits of ± 0.5 mm the accuracy achieved was 90% for Root ZX, 68% for Bingo and 52% for the Ipex. Conclusion: It was concluded that all electronic devices tested were able in determining the precise tooth length when considered a variation of 1 mm from the position of apical foramen. Nevertheless, when considered a variation of 0.5 mm, only the unit Root ZX proved to be accurate.

  8. Prospective analysis of the accuracy of diagnosis of carpal tunnel syndrome using a web-based questionnaire

    OpenAIRE

    Bland, Jeremy D P; Rudolfer, Stephan; Weller, Peter

    2014-01-01

    Objective To confirm the accuracy of a diagnostic questionnaire for carpal tunnel syndrome (CTS) when presented via a public website rather than on paper. Design Prospective comparison of the probability of CTS as assessed by the web-based questionnaire at http://www.carpal-tunnel.net with the results of nerve conduction studies. Setting Subregional neurophysiology laboratory serving a population of 700 000 in East Kent, UK. Participants 2821 individuals who were able to complete an online di...

  9. Accuracy of Self-reported Hypertension, Diabetes, and Hypercholesterolemia: Analysis of a Representative Sample of Korean Older Adults

    OpenAIRE

    Chun, Heeran; Kim, Il-Ho; Min, Kyung-Duk

    2015-01-01

    Objectives This study will assess the accuracy of self-reported hypertension, diabetes, and hypercholesterolemia among Korean older adults. Methods Using data from the fourth Korean National Health Examination and Nutrition Survey (KNHANES IV, 2007–2009), we selected 7,270 individuals aged 50 years and older who participated in both a health examination and a health interview survey. Self-reported prevalence of hypertension (HTN), diabetes mellitus (DM), and hypercholesterolemia was compared ...

  10. Comparing the accuracy of video-oculography and the scleral search coil system in human eye movement analysis.

    Science.gov (United States)

    Imai, Takao; Sekine, Kazunori; Hattori, Kousuke; Takeda, Noriaki; Koizuka, Izumi; Nakamae, Koji; Miura, Katsuyoshi; Fujioka, Hiromu; Kubo, Takeshi

    2005-03-01

    The measurement of eye movements in three dimensions is an important tool to investigate the human vestibular and oculomotor system. The primary methods for three dimensional eye movement measurement are the scleral search coil system (SSCS) and video-oculography (VOG). In the present study, we compare the accuracy of VOG with that of SSCS using an artificial eye. We then analyzed the Y (pitch) and Z (yaw) component of human eye movements during saccades, smooth pursuit and optokinetic nystagmus, and the X (roll) component of human eye movement during the torsional vestibulo-ocular reflex induced by rotation in normal subjects, using simultaneous VOG and SSCS measures. The coefficients of the linear relationship between the angle of a simulated eyeball and the angle measured by both VOG and SSCS was almost unity with y-intercepts close to zero for torsional (X), vertical (Y) and horizontal (Z) movements, indicating that the in vitro accuracy of VOG was similar to that of SSCS. The average difference between VOG and SSCS was 0.56 degrees , 0.78 degrees and 0.18 degrees for the X, Y and Z components of human eye movements, respectively. Both the in vitro and in vivo comparisons demonstrate that VOG has accuracy comparable to SSCS, and is a reliable method for measurement of three dimensions (3D) human eye movements.

  11. Accuracy Analysis of a Multi-View Stereo Approach for Phenotyping of Tomato Plants at the Organ Level

    Directory of Open Access Journals (Sweden)

    Johann Christian Rose

    2015-04-01

    Full Text Available Accessing a plant’s 3D geometry has become of significant importance for phenotyping during the last few years. Close-up laser scanning is an established method to acquire 3D plant shapes in real time with high detail, but it is stationary and has high investment costs. 3D reconstruction from images using structure from motion (SfM and multi-view stereo (MVS is a flexible cost-effective method, but requires post-processing procedures. The aim of this study is to evaluate the potential measuring accuracy of an SfM- and MVS-based photogrammetric method for the task of organ-level plant phenotyping. For this, reference data are provided by a high-accuracy close-up laser scanner. Using both methods, point clouds of several tomato plants were reconstructed at six following days. The parameters leaf area, main stem height and convex hull of the complete plant were extracted from the 3D point clouds and compared to the reference data regarding accuracy and correlation. These parameters were chosen regarding the demands of current phenotyping scenarios. The study shows that the photogrammetric approach is highly suitable for the presented monitoring scenario, yielding high correlations to the reference measurements. This cost-effective 3D reconstruction method depicts an alternative to an expensive laser scanner in the studied scenarios with potential for automated procedures.

  12. Experiment and Accuracy Analysis of GPS Dynamic Monitoring%GPS动态监测试验与精度分析

    Institute of Scientific and Technical Information of China (English)

    刘振承

    2011-01-01

    由于GPS定位精度的不断提高,其在工程变形监测中得到了越来越广泛的应用。结合一次动态监测实验,客观评价了GPS的精度,本文介绍了该试验的实施方案及监测结果,并通过大量实验数据统计分析了此次GPS动态监测的精度,取得了不错的效果。试验证明,GPS动态监测能够满足工程应用的需要。%As the accuracy of GPS positioning has been improved so much,it is used in deformation monitoring of projects more and more.To evaluate the accuracy of GPS dynamic monitoring,according to the experiment of GPS dynamic monitoring,this paper introduces its experimental implementing scheme and results.It also analyses the accuracy of GPS dynamic monitoring through a large number of experimental data,the result is satisfactory.It demonstrates that GPS dynamic monitoring could meet the needs of project.

  13. Thiopurine S-methyltransferase testing for averting drug toxicity: a meta-analysis of diagnostic test accuracy.

    Science.gov (United States)

    Zur, R M; Roy, L M; Ito, S; Beyene, J; Carew, C; Ungar, W J

    2016-08-01

    Thiopurine S-methyltransferase (TPMT) deficiency increases the risk of serious adverse events in persons receiving thiopurines. The objective was to synthesize reported sensitivity and specificity of TPMT phenotyping and genotyping using a latent class hierarchical summary receiver operating characteristic meta-analysis. In 27 studies, pooled sensitivity and specificity of phenotyping for deficient individuals was 75.9% (95% credible interval (CrI), 58.3-87.0%) and 98.9% (96.3-100%), respectively. For genotype tests evaluating TPMT*2 and TPMT*3, sensitivity and specificity was 90.4% (79.1-99.4%) and 100.0% (99.9-100%), respectively. For individuals with deficient or intermediate activity, phenotype sensitivity and specificity was 91.3% (86.4-95.5%) and 92.6% (86.5-96.6%), respectively. For genotype tests evaluating TPMT*2 and TPMT*3, sensitivity and specificity was 88.9% (81.6-97.5%) and 99.2% (98.4-99.9%), respectively. Genotyping has higher sensitivity as long as TPMT*2 and TPMT*3 are tested. Both approaches display high specificity. Latent class meta-analysis is a useful method for synthesizing diagnostic test performance data for clinical practice guidelines.The Pharmacogenomics Journal advance online publication, 24 May 2016; doi:10.1038/tpj.2016.37. PMID:27217052

  14. ANALYSIS OF PSEUDORANGE POINT POSITIONING ACCURACY OF COMPASS%COMPASS伪距单点定位精度分析

    Institute of Scientific and Technical Information of China (English)

    李林红; 何秀凤; 张化疑

    2013-01-01

    The relations between the accuracy of COMPASS pseudorange observations and elevation angles of satellite are studied, and the pseudorange point positioning accuracy of the constellation which contains 4 Geosta tionary Orbit(GEO) satellites and 5 Inclined Geo-synchronization Orbit (IGSO) satellites is analyzed. The results demonstrate multi-path effects of COMPASS pseudorange and observation noise are about 0 - 3 m, and their accura cies are about 0. 3 -0. 7 m. At the higher elevation angles, multi-path effects and observation noise are the smal ler, and both of the multi-path effects and observation noise on all GEO satellites are smaller than those on IGSO satellites. The COMPASS pseudorange point positioning accuracy ( RMS) in the N, E and U directions are about 3. 33 , 3. 45 and 8. 84 m, respectively.%通过实测COMPASS数据处理,分析COMPASS伪距观测值精度与卫星高度角的关系,以及当前4GEO+5IGSO导航星座COMPASS伪距单点定位的精度.结果表明,COMPASS伪距多路径效应和观测噪声在0~3m之间变化,其精度为0.3 ~0.7 m;卫星高度角越大,多路径效应和观测噪声越小;GEO卫星受到的多路径效应和观测噪声要明显小于IGSO卫星;COMPASS伪距单点定位精度(RMS)在N、E、U方向上分别为3.33、3.45、8.84m.

  15. Detection accuracy of root fractures in cone-beam computed tomography images: a systematic review and meta-analysis.

    Science.gov (United States)

    Ma, R H; Ge, Z P; Li, G

    2016-07-01

    The aim of this review was to evaluate whether CBCT is reliable for the detection of root fractures in teeth without root fillings, and whether the voxel size has an impact on diagnostic accuracy. The studies published in PubMed, Web of Science, ScienceDirect, Cochrane Library, Embase, Scopus, CNKI and Wanfang up to May 2014 were the data source. Studies on nonroot filled teeth with the i-CAT (n = 8) and 3D Accuitomo CBCT (n = 5) units were eventually selected. In the studies on i-CAT, the pooled sensitivity was 0.83 and the pooled specificity was 0.91; in the 3D Accuitomo studies, the pooled sensitivity was 0.95 and pooled specificity was 0.96. The i-CAT group comprised 5 voxel size subgroups and the 3D Accuitomo group contained 2 subgroups. For the i-CAT group, there was a significant difference amongst the five subgroups (0.125, 0.2, 0.25, 0.3 and 0.4 mm; P = 0.000). Pairwise comparison revealed that 0.125 mm voxel subgroup was significantly different from those of 0.2, 0.25 and 0.3 mm voxel subgroups, but not from the 0.4 mm voxel subgroup. There were no significant differences amongst any other two subgroups (by α' = 0.005). No significant difference was found between 0.08 mm and 0.125 mm voxel subgroups (P = 0.320) for the 3D Accuitomo group. The present review confirms the detection accuracy of root fractures in CBCT images, but does not support the concept that voxel size may play a role in improving the detection accuracy of root fractures in nonroot filled teeth. PMID:26102215

  16. UV-visible microscope spectrophotometric polarization and dichroism with increased discrimination power in forensic analysis

    Science.gov (United States)

    Purcell, Dale Kevin

    merit investigated included: 1) wavelength accuracy, 2) wavelength precision, 3) wavelength resolution stability, 4) photometric accuracy, 5) photometric precision, 6) photometric linearity, 7) photometric noise, and 8) short-term baseline stability. In addition, intrinsic instrument polarization effects were investigated to determine the impact of these properties on spectral interpretation and data quality. Finally, a set of recommendations were developed which describe instrument performance characteristics for microscope and spectrometer features and functions, and specific instrument parameters that must be controlled in order to acquire high quality data from an ultraviolet-visible forensic microscope spectrophotometer system for increased discrimination power.

  17. The zero-multipole summation method for estimating electrostatic interactions in molecular dynamics: Analysis of the accuracy and application to liquid systems

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, Ikuo, E-mail: ifukuda@protein.osaka-u.ac.jp [Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); RIKEN (The Institute of Physical and Chemical Research), 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Kamiya, Narutoshi; Nakamura, Haruki [Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2014-05-21

    In the preceding paper [I. Fukuda, J. Chem. Phys. 139, 174107 (2013)], the zero-multipole (ZM) summation method was proposed for efficiently evaluating the electrostatic Coulombic interactions of a classical point charge system. The summation takes a simple pairwise form, but prevents the electrically non-neutral multipole states that may artificially be generated by a simple cutoff truncation, which often causes large energetic noises and significant artifacts. The purpose of this paper is to judge the ability of the ZM method by investigating the accuracy, parameter dependencies, and stability in applications to liquid systems. To conduct this, first, the energy-functional error was divided into three terms and each term was analyzed by a theoretical error-bound estimation. This estimation gave us a clear basis of the discussions on the numerical investigations. It also gave a new viewpoint between the excess energy error and the damping effect by the damping parameter. Second, with the aid of these analyses, the ZM method was evaluated based on molecular dynamics (MD) simulations of two fundamental liquid systems, a molten sodium-chlorine ion system and a pure water molecule system. In the ion system, the energy accuracy, compared with the Ewald summation, was better for a larger value of multipole moment l currently induced until l ≲ 3 on average. This accuracy improvement with increasing l is due to the enhancement of the excess-energy accuracy. However, this improvement is wholly effective in the total accuracy if the theoretical moment l is smaller than or equal to a system intrinsic moment L. The simulation results thus indicate L ∼ 3 in this system, and we observed less accuracy in l = 4. We demonstrated the origins of parameter dependencies appearing in the crossing behavior and the oscillations of the energy error curves. With raising the moment l we observed, smaller values of the damping parameter provided more accurate results and smoother

  18. The zero-multipole summation method for estimating electrostatic interactions in molecular dynamics: analysis of the accuracy and application to liquid systems.

    Science.gov (United States)

    Fukuda, Ikuo; Kamiya, Narutoshi; Nakamura, Haruki

    2014-05-21

    In the preceding paper [I. Fukuda, J. Chem. Phys. 139, 174107 (2013)], the zero-multipole (ZM) summation method was proposed for efficiently evaluating the electrostatic Coulombic interactions of a classical point charge system. The summation takes a simple pairwise form, but prevents the electrically non-neutral multipole states that may artificially be generated by a simple cutoff truncation, which often causes large energetic noises and significant artifacts. The purpose of this paper is to judge the ability of the ZM method by investigating the accuracy, parameter dependencies, and stability in applications to liquid systems. To conduct this, first, the energy-functional error was divided into three terms and each term was analyzed by a theoretical error-bound estimation. This estimation gave us a clear basis of the discussions on the numerical investigations. It also gave a new viewpoint between the excess energy error and the damping effect by the damping parameter. Second, with the aid of these analyses, the ZM method was evaluated based on molecular dynamics (MD) simulations of two fundamental liquid systems, a molten sodium-chlorine ion system and a pure water molecule system. In the ion system, the energy accuracy, compared with the Ewald summation, was better for a larger value of multipole moment l currently induced until l ≲ 3 on average. This accuracy improvement with increasing l is due to the enhancement of the excess-energy accuracy. However, this improvement is wholly effective in the total accuracy if the theoretical moment l is smaller than or equal to a system intrinsic moment L. The simulation results thus indicate L ∼ 3 in this system, and we observed less accuracy in l = 4. We demonstrated the origins of parameter dependencies appearing in the crossing behavior and the oscillations of the energy error curves. With raising the moment l we observed, smaller values of the damping parameter provided more accurate results and smoother

  19. Experimental analysis of multi-attribute decision-making based on Atanassov intuitionistic fuzzy sets: a discussion of anchor dependency and accuracy functions

    Science.gov (United States)

    Chen, Ting-Yu

    2012-06-01

    This article presents a useful method for relating anchor dependency and accuracy functions to multiple attribute decision-making (MADM) problems in the context of Atanassov intuitionistic fuzzy sets (A-IFSs). Considering anchored judgement with displaced ideals and solution precision with minimal hesitation, several auxiliary optimisation models have proposed to obtain the optimal weights of the attributes and to acquire the corresponding TOPSIS (the technique for order preference by similarity to the ideal solution) index for alternative rankings. Aside from the TOPSIS index, as a decision-maker's personal characteristics and own perception of self may also influence the direction in the axiom of choice, the evaluation of alternatives is conducted based on distances of each alternative from the positive and negative ideal alternatives, respectively. This article originates from Li's [Li, D.-F. (2005), 'Multiattribute Decision Making Models and Methods Using Intuitionistic Fuzzy Sets', Journal of Computer and System Sciences, 70, 73-85] work, which is a seminal study of intuitionistic fuzzy decision analysis using deduced auxiliary programming models, and deems it a benchmark method for comparative studies on anchor dependency and accuracy functions. The feasibility and effectiveness of the proposed methods are illustrated by a numerical example. Finally, a comparative analysis is illustrated with computational experiments on averaging accuracy functions, TOPSIS indices, separation measures from positive and negative ideal alternatives, consistency rates of ranking orders, contradiction rates of the top alternative and average Spearman correlation coefficients.

  20. Diagnostic accuracy of {sup 18}F amyloid PET tracers for the diagnosis of Alzheimer's disease: a systematic review and meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Morris, Elizabeth; Chalkidou, Anastasia [St Thomas' Hospital, King' s Technology Evaluation Centre, King' s College London, London (United Kingdom); St Thomas' Hospital, Department of Biomedical Engineering, Division of Imaging Sciences and Biomedical Engineering, King' s College London, London (United Kingdom); Hammers, Alexander [St Thomas' Hospital, Department of Biomedical Engineering, Division of Imaging Sciences and Biomedical Engineering, King' s College London, London (United Kingdom); Peacock, Janet; Summers, Jennifer [St Thomas' Hospital, King' s Technology Evaluation Centre, King' s College London, London (United Kingdom); King' s College London, Division of Health and Social Care Research, London (United Kingdom); King' s College London, NIHR Biomedical Research Centre at Guy' s and St Thomas' NHS Foundation Trust, London (United Kingdom); Keevil, Stephen [St Thomas' Hospital, King' s Technology Evaluation Centre, King' s College London, London (United Kingdom); St Thomas' Hospital, Department of Biomedical Engineering, Division of Imaging Sciences and Biomedical Engineering, King' s College London, London (United Kingdom); St Thomas' Hospital, Department of Medical Physics, Guy' s and St Thomas' NHS Foundation Trust, London (United Kingdom)

    2016-02-15

    Imaging or tissue biomarker evidence has been introduced into the core diagnostic pathway for Alzheimer's disease (AD). PET using {sup 18}F-labelled beta-amyloid PET tracers has shown promise for the early diagnosis of AD. However, most studies included only small numbers of participants and no consensus has been reached as to which radiotracer has the highest diagnostic accuracy. First, we performed a systematic review of the literature published between 1990 and 2014 for studies exploring the diagnostic accuracy of florbetaben, florbetapir and flutemetamol in AD. The included studies were analysed using the QUADAS assessment of methodological quality. A meta-analysis of the sensitivity and specificity reported within each study was performed. Pooled values were calculated for each radiotracer and for visual or quantitative analysis by population included. The systematic review identified nine studies eligible for inclusion. There were limited variations in the methods between studies reporting the same radiotracer. The meta-analysis results showed that pooled sensitivity and specificity values were in general high for all tracers. This was confirmed by calculating likelihood ratios. A patient with a positive ratio is much more likely to have AD than a patient with a negative ratio, and vice versa. However, specificity was higher when only patients with AD were compared with healthy controls. This systematic review and meta-analysis found no marked differences in the diagnostic accuracy of the three beta-amyloid radiotracers. All tracers perform better when used to discriminate between patients with AD and healthy controls. The sensitivity and specificity for quantitative and visual analysis are comparable to those of other imaging or biomarker techniques used to diagnose AD. Further research is required to identify the combination of tests that provides the highest sensitivity and specificity, and to identify the most suitable position for the tracer in the

  1. Data accuracy assessment using enterprise architecture

    Science.gov (United States)

    Närman, Per; Holm, Hannes; Johnson, Pontus; König, Johan; Chenine, Moustafa; Ekstedt, Mathias

    2011-02-01

    Errors in business processes result in poor data accuracy. This article proposes an architecture analysis method which utilises ArchiMate and the Probabilistic Relational Model formalism to model and analyse data accuracy. Since the resources available for architecture analysis are usually quite scarce, the method advocates interviews as the primary data collection technique. A case study demonstrates that the method yields correct data accuracy estimates and is more resource-efficient than a competing sampling-based data accuracy estimation method.

  2. Accuracy assessments and uncertainty analysis of spatially explicit modeling for land use/cover change and urbanization:A case in Beijing metropolitan area

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Spatially explicit modeling plays a vital role in land use/cover change and urbanization research as well as resources management;however,current models lack proper validation and fail to incorporate uncertainty into the formulation of model predictions.Consequently,policy makers and the general public may develop opinions based on potentially misleading research,which fails to allow for truly informed decisions.Here we use an uncertainty strategy of spatially explicit modeling combined with the series statistic of Kappa index for location and quantity to estimate the uncertainty of future predications and to determine model accuracy.We take the Beijing metropolitan area as an example to demonstrate the uncertainty in extrapolations of predictive land use change and urban sprawl with spatially explicit modeling at multiple resolutions.The sensitivity of scale effects is also discussed.The results show that an improvement in specification of location is more helpful in increasing accuracy as compared to an improvement in the specification of quantity at fine spatial resolutions.However,the spatial scale has great effects on modeling accuracy and correct due to chance tends to increase as resolution becomes coarser.The results allow us to understand the uncertainty when using spatially explicit models for land-use change or urbanization estimates.

  3. Diagnostic Accuracy of Serum Procalcitonin for Spontaneous Bacterial Peritonitis Due to End-stage Liver Disease: A Meta-analysis.

    Science.gov (United States)

    Yang, Yongtao; Li, Lianyong; Qu, Changmin; Zeng, Bolun; Liang, Shuwen; Luo, Zhiwen; Wang, Xiaoying; Zhong, Changqing

    2015-12-01

    Early diagnosis and prompt treatment of spontaneous bacterial peritonitis (SBP) due to end-stage liver disease is vital to shorten hospital stays and reduce mortality. Many studies have explored the potential usefulness of serum procalcitonin (PCT) in predicting SBP. The aim of this study is to evaluate the overall diagnostic accuracy of PCT levels for identifying SBP due to end-stage liver disease.After performing a systematic search of the Medline, Embase, and Cochrane databases for studies that evaluated the diagnostic role of PCT for SBP, sensitivity, specificity, and other measures of accuracy of PCT concentrations in serum for SBP diagnosis were pooled using random-effects models. A summary receiver operating characteristic curve was used to summarize overall test performance.Seven publications met the inclusion criteria covering 742 episodes of suspected SBP along with 339 confirmed cases. The summary estimates for serum PCT in the diagnosis of SBP attributable to end-stage liver disease were: sensitivity 0.82 (95% CI 0.79-0.87), specificity 0.86 (95% CI 0.82-0.89), positive likelihood ratio 4.94 (95% CI 2.28-10.70), negative likelihood ratio 0.22 (95% CI 0.10-0.52), and diagnostic OR 22.55 (95% CI 7.01-108.30). The area under the curve was 0.92. There was evidence of significant heterogeneity but no evidence of publication bias.Serum PCT is a relatively sensitive and specific test for the identification of SBP. However, due to the limited high-quality studies available, medical decisions should be carefully made in the context of both PCT test results and other clinical findings.

  4. Diagnostic accuracy of cytokeratin-19 fragment (CYFRA 21-1) for bladder cancer: a systematic review and meta-analysis.

    Science.gov (United States)

    Huang, Yuan-Lan; Chen, Jie; Yan, Wei; Zang, Ding; Qin, Qin; Deng, An-Mei

    2015-05-01

    Previous studies have evaluated the accuracy of serum and urinary measurements of cytokeratin-19 fragment (CYFRA 21-1) for the diagnosis of bladder cancer; however, the results have been inconsistent. The aim of this study was to evaluate the overall accuracy of CYFRA 21-1 for the diagnosis of bladder cancer. We performed a search for English-language publications reporting on the detection of CYFRA21-1 levels for the diagnosis of bladder cancer through November 2, 2014, using public medical databases, including EMBASE, Web of Science, and Medline. The quality of the studies was assessed by revised QUADAS tools. The performance characteristics were pooled and analyzed using a bivariate model. Publication bias was explored with the Deek's test. Sixteen studies, with a total 1,262 bladder-cancer patients and 1,233 non-bladder-cancer patients, were included in the study. The pooled sensitivities for serum and urine CYFRA 21-1 were 0.42 (95 % confidence interval (CI), 0.33-0.51) and 0.82 (95 % CI, 0.70-0.90), respectively. The corresponding specificities were 0.94 (95 % CI, 0.90-0.96) and 0.80 (95 % CI, 0.73-0.86), respectively. The areas under the summary receiver-operating-characteristic curves for serum and urine CYFRA 21-1 were 0.88 (95 % CI, 0.85-0.91) and 0.87 (95 % CI, 0.84-0.90), respectively. The major design deficiencies of the included studies were participant-selection bias, potential review, and verification bias. Therefore, we concluded that both serum and urine CYFRA 21-1 served as efficient indexes for bladder-cancer diagnosis. Additional, well-designed studies should be performed to rigorously evaluate the diagnostic value of CYFRA 21-1 for bladder cancer. PMID:25854170

  5. Fractionated stereotactic radiotherapy for skull base tumors: analysis of treatment accuracy using a stereotactic mask fixation system

    Directory of Open Access Journals (Sweden)

    Montagnoli Roberto

    2010-01-01

    Full Text Available Abstract Background To assess the accuracy of fractionated stereotactic radiotherapy (FSRT using a stereotactic mask fixation system. Patients and Methods Sixteen patients treated with FSRT were involved in the study. A commercial stereotactic mask fixation system (BrainLAB AG was used for patient immobilization. Serial CT scans obtained before and during FSRT were used to assess the accuracy of patient immobilization by comparing the isocenter position. Daily portal imaging were acquired to establish day to day patient position variation. Displacement errors along the different directions were calculated as combination of systematic and random errors. Results The mean isocenter displacements based on localization and verification CT imaging were 0.1 mm (SD 0.3 mm in the lateral direction, 0.1 mm (SD 0.4 mm in the anteroposterior, and 0.3 mm (SD 0.4 mm in craniocaudal direction. The mean 3D displacement was 0.5 mm (SD 0.4 mm, being maximum 1.4 mm. No significant differences were found during the treatment (P = 0.4. The overall isocenter displacement as calculated by 456 anterior and lateral portal images were 0.3 mm (SD 0.9 mm in the mediolateral direction, -0.2 mm (SD 1 mm in the anteroposterior direction, and 0.2 mm (SD 1.1 mm in the craniocaudal direction. The largest displacement of 2.7 mm was seen in the cranio-caudal direction, with 95% of displacements Conclusions The results indicate that the setup error of the presented mask system evaluated by CT verification scans and portal imaging are minimal. Reproducibility of the isocenter position is in the best range of positioning reproducibility reported for other stereotactic systems.

  6. Target Price Accuracy

    OpenAIRE

    Alexander G. Kerl

    2011-01-01

    This study analyzes the accuracy of forecasted target prices within analysts’ reports. We compute a measure for target price forecast accuracy that evaluates the ability of analysts to exactly forecast the ex-ante (unknown) 12-month stock price. Furthermore, we determine factors that explain this accuracy. Target price accuracy is negatively related to analyst-specific optimism and stock-specific risk (measured by volatility and price-to-book ratio). However, target price accuracy is positive...

  7. Effects of increasing age, dosage, and duration of PTH treatment on BMD increase--a meta-analysis

    DEFF Research Database (Denmark)

    Schwarz, Peter; Jorgensen, Niklas Rye; Mosekilde, Leif;

    2012-01-01

    We studied the effects of increasing age, dosage, and duration of parathyroid hormone (PTH) treatment on changes in bone mineral density (BMD). Randomized placebo controlled trials on PTH treatment in men or women were retrieved from PubMed (1951 to present), Web of Science (1945 to present......), or Embase (1974 to present). The search date was November 16, 2010. All studies comparing PTH treatment to either placebo or antiresorptive drugs-for example, bisphosphonates or hormone replacement therapy-were included. A total of 214 studies were identified in the initial search, and 15 of these trials...... were included. By metaregression analysis, we found that the increase in spine BMD (Z-score) after PTH treatment was blunted by increasing age (R (2) = 0.27; 2p = 0.01, slope -0.023 Z-scores per year, 11 studies). By increasing PTH dosage (μg/d), spine BMD increased significantly (2p = 0...

  8. Comparison of the accuracy of Hybrid Capture II and polymerase chain reaction in detecting clinically important cervical dysplasia: a systematic review and meta-analysis.

    Science.gov (United States)

    Luu, Hung N; Dahlstrom, Kristina R; Mullen, Patricia Dolan; VonVille, Helena M; Scheurer, Michael E

    2013-06-01

    The effectiveness of screening programs for cervical cancer has benefited from the inclusion of Human papillomavirus (HPV) DNA assays; which assay to choose, however, is not clear based on previous reviews. Our review addressed test accuracy of Hybrid Capture II (HCII) and polymerase chain reaction (PCR) assays based on studies with stronger designs and with more clinically relevant outcomes. We searched OvidMedline, PubMed, and the Cochrane Library for English language studies comparing both tests, published 1985-2012, with cervical dysplasia defined by the Bethesda classification. Meta-analysis provided pooled sensitivity, specificity, and 95% confidence intervals (CIs); meta-regression identified sources of heterogeneity. From 29 reports, we found that the pooled sensitivity and specificity to detect high-grade squamous intraepithelial lesion (HSIL) was higher for HCII than PCR (0.89 [CI: 0.89-0.90] and 0.85 [CI: 0.84-0.86] vs. 0.73 [CI: 0.73-0.74] and 0.62 [CI: 0.62-0.64]). Both assays had higher accuracy to detect cervical dysplasia in Europe than in Asia-Pacific or North America (diagnostic odd ratio - dOR = 4.08 [CI: 1.39-11.91] and 4.56 [CI: 1.86-11.17] for HCII vs. 2.66 [CI: 1.16-6.53] and 3.78 [CI: 1.50-9.51] for PCR) and accuracy to detect HSIL than atypical squamous cells of undetermined significance (ASCUS)/ low-grade squamous intraepithelial lesion (LSIL) (HCII-dOR = 9.04 [CI: 4.12-19.86] and PCR-dOR = 5.60 [CI: 2.87-10.94]). For HCII, using histology as a gold standard results in higher accuracy than using cytology (dOR = 2.87 [CI: 1.31-6.29]). Based on higher test accuracy, our results support the use of HCII in cervical cancer screening programs. The role of HPV type distribution should be explored to determine the worldwide comparability of HPV test accuracy.

  9. Comparison of the accuracy of Hybrid Capture II and polymerase chain reaction in detecting clinically important cervical dysplasia: a systematic review and meta-analysis

    Science.gov (United States)

    Luu, Hung N; Dahlstrom, Kristina R; Mullen, Patricia Dolan; VonVille, Helena M; Scheurer, Michael E

    2013-01-01

    The effectiveness of screening programs for cervical cancer has benefited from the inclusion of Human papillomavirus (HPV) DNA assays; which assay to choose, however, is not clear based on previous reviews. Our review addressed test accuracy of Hybrid Capture II (HCII) and polymerase chain reaction (PCR) assays based on studies with stronger designs and with more clinically relevant outcomes. We searched OvidMedline, PubMed, and the Cochrane Library for English language studies comparing both tests, published 1985–2012, with cervical dysplasia defined by the Bethesda classification. Meta-analysis provided pooled sensitivity, specificity, and 95% confidence intervals (CIs); meta-regression identified sources of heterogeneity. From 29 reports, we found that the pooled sensitivity and specificity to detect high-grade squamous intraepithelial lesion (HSIL) was higher for HCII than PCR (0.89 [CI: 0.89–0.90] and 0.85 [CI: 0.84–0.86] vs. 0.73 [CI: 0.73–0.74] and 0.62 [CI: 0.62–0.64]). Both assays had higher accuracy to detect cervical dysplasia in Europe than in Asia-Pacific or North America (diagnostic odd ratio – dOR = 4.08 [CI: 1.39–11.91] and 4.56 [CI: 1.86–11.17] for HCII vs. 2.66 [CI: 1.16–6.53] and 3.78 [CI: 1.50–9.51] for PCR) and accuracy to detect HSIL than atypical squamous cells of undetermined significance (ASCUS)/ low-grade squamous intraepithelial lesion (LSIL) (HCII-dOR = 9.04 [CI: 4.12–19.86] and PCR-dOR = 5.60 [CI: 2.87–10.94]). For HCII, using histology as a gold standard results in higher accuracy than using cytology (dOR = 2.87 [CI: 1.31–6.29]). Based on higher test accuracy, our results support the use of HCII in cervical cancer screening programs. The role of HPV type distribution should be explored to determine the worldwide comparability of HPV test accuracy. PMID:23930214

  10. Comparison of the accuracy of Hybrid Capture II and polymerase chain reaction in detecting clinically important cervical dysplasia: a systematic review and meta-analysis

    International Nuclear Information System (INIS)

    The effectiveness of screening programs for cervical cancer has benefited from the inclusion of Human papillomavirus (HPV) DNA assays; which assay to choose, however, is not clear based on previous reviews. Our review addressed test accuracy of Hybrid Capture II (HCII) and polymerase chain reaction (PCR) assays based on studies with stronger designs and with more clinically relevant outcomes. We searched OvidMedline, PubMed, and the Cochrane Library for English language studies comparing both tests, published 1985–2012, with cervical dysplasia defined by the Bethesda classification. Meta-analysis provided pooled sensitivity, specificity, and 95% confidence intervals (CIs); meta-regression identified sources of heterogeneity. From 29 reports, we found that the pooled sensitivity and specificity to detect high-grade squamous intraepithelial lesion (HSIL) was higher for HCII than PCR (0.89 [CI: 0.89–0.90] and 0.85 [CI: 0.84–0.86] vs. 0.73 [CI: 0.73–0.74] and 0.62 [CI: 0.62–0.64]). Both assays had higher accuracy to detect cervical dysplasia in Europe than in Asia-Pacific or North America (diagnostic odd ratio – dOR = 4.08 [CI: 1.39–11.91] and 4.56 [CI: 1.86–11.17] for HCII vs. 2.66 [CI: 1.16–6.53] and 3.78 [CI: 1.50–9.51] for PCR) and accuracy to detect HSIL than atypical squamous cells of undetermined significance (ASCUS)/ low-grade squamous intraepithelial lesion (LSIL) (HCII-dOR = 9.04 [CI: 4.12–19.86] and PCR-dOR = 5.60 [CI: 2.87–10.94]). For HCII, using histology as a gold standard results in higher accuracy than using cytology (dOR = 2.87 [CI: 1.31–6.29]). Based on higher test accuracy, our results support the use of HCII in cervical cancer screening programs. The role of HPV type distribution should be explored to determine the worldwide comparability of HPV test accuracy

  11. Diagnostic accuracy in virtual dermatopathology

    DEFF Research Database (Denmark)

    Mooney, E.; Kempf, W.; Jemec, G.B.E.;

    2012-01-01

    diagnostic accuracy of dermatopathologists and pathologists using photomicrographs vs. digitized images, through a self-assessment examination, and to elucidate assessment of virtual dermatopathology. Methods Forty-five dermatopathologists and pathologists received a randomized combination of 15 virtual...... slides and photomicrographs with corresponding clinical photographs and information in a self-assessment examination format. Descriptive data analysis and comparison of groups were performed using a chi-square test. Results Diagnostic accuracy in dermatopathology using virtual dermatopathology...

  12. A mixed effect model for bivariate meta-analysis of diagnostic test accuracy studies using a copula representation of the random effects distribution.

    Science.gov (United States)

    Nikoloulopoulos, Aristidis K

    2015-12-20

    Diagnostic test accuracy studies typically report the number of true positives, false positives, true negatives and false negatives. There usually exists a negative association between the number of true positives and true negatives, because studies that adopt less stringent criterion for declaring a test positive invoke higher sensitivities and lower specificities. A generalized linear mixed model (GLMM) is currently recommended to synthesize diagnostic test accuracy studies. We propose a copula mixed model for bivariate meta-analysis of diagnostic test accuracy studies. Our general model includes the GLMM as a special case and can also operate on the original scale of sensitivity and specificity. Summary receiver operating characteristic curves are deduced for the proposed model through quantile regression techniques and different characterizations of the bivariate random effects distribution. Our general methodology is demonstrated with an extensive simulation study and illustrated by re-analysing the data of two published meta-analyses. Our study suggests that there can be an improvement on GLMM in fit to data and makes the argument for moving to copula random effects models. Our modelling framework is implemented in the package CopulaREMADA within the open source statistical environment R.

  13. Diagnostic accuracy of point-of-care tests for hepatitis C virus infection: a systematic review and meta-analysis.

    Directory of Open Access Journals (Sweden)

    Mehnaaz Sultan Khuroo

    Full Text Available Point-of-care tests provide a plausible diagnostic strategy for hepatitis C infection in economically impoverished areas. However, their utility depends upon the overall performance of individual tests.A literature search was conducted using the metasearch engine Mettā, a query interface for retrieving articles from five leading medical databases. Studies were included if they employed point-of-care tests to detect antibodies of hepatitis C virus and compared the results with reference tests. Two reviewers performed a quality assessment of the studies and extracted data for estimating test accuracy.Thirty studies that had evaluated 30 tests fulfilled the inclusion criteria. The overall pooled sensitivity, specificity, positive likelihood-ratio, negative likelihood-ratio and diagnostic odds ratio for all tests were 97.4% (95% CI: 95.9-98.4, 99.5% (99.2-99.7, 80.17 (55.35-116.14, 0.03 (0.02-0.04, and 3032.85 (1595.86-5763.78, respectively. This suggested a high pooled accuracy for all studies. We found substantial heterogeneity between studies, but none of the subgroups investigated could account for the heterogeneity. Genotype diversity of HCV had no or minimal influence on test performance. Of the seven tests evaluated in the meta-regression model, OraQuick had the highest test sensitivity and specificity and showed better performance than a third generation enzyme immunoassay in seroconversion panels. The next highest test sensitivities and specificities were from TriDot and SDBioline, followed by Genedia and Chembio. The Spot and Multiplo tests produced poor test sensitivities but high test specificities. Nine of the remaining 23 tests produced poor test sensitivities and specificities and/or showed poor performances in seroconversion panels, while 14 tests had high test performances with diagnostic odds ratios ranging from 590.70 to 28822.20.Performances varied widely among individual point-of-care tests for diagnosis of hepatitis C virus

  14. Accuracy of non-invasive techniques for diagnosis of coronary artery disease and prediction of cardiac events in patients with left bundle branch block: a meta-analysis

    International Nuclear Information System (INIS)

    Non-invasive evaluation of coronary artery disease (CAD) in patients with left bundle branch block (LBBB) has limitations inherent to different tests, and the relative merits of these tests are unclear. This meta-analysis assessed the accuracy of the frequently used non-invasive techniques, including exercise electrocardiography (ECG), myocardial perfusion imaging (MPI) and stress echocardiography (SE), for detection of CAD and prediction of cardiac events in patients with LBBB. A review was conducted of all reports on detection of CAD and prediction of cardiac events in patients with LBBB (published between January 1970 and December 2004), and revealed 55 diagnostic and nine prognostic reports with sufficient details to calculate test accuracy. Weighted (by sample size) sensitivity and specificity were calculated. Summary relative risk ratios (95% confidence intervals) were calculated. Overall sensitivity was higher for exercise ECG and (quantitatively analysed) MPI than for SE (83.4% and 88.5% versus 74.6% respectively, p<0.0001). SE had a higher specificity (88.7%) than MPI (41.2%) and exercise ECG (60.1%) (p<0.0001). Based on analysis of eight reports, the relative risk of cardiac death or myocardial infarction in patients with an abnormal SE and MPI was elevated more than sevenfold, but it did not differ by imaging modality (p=0.9). Meta-analysis of non-invasive CAD assessment in LBBB patients revealed that exercise ECG and MPI had the highest sensitivity, while SE had the highest specificity. The prognostic accuracy of MPI and SE appeared similar. (orig.)

  15. Curriculum-based measurement of oral reading (R-CBM): a diagnostic test accuracy meta-analysis of evidence supporting use in universal screening.

    Science.gov (United States)

    Kilgus, Stephen P; Methe, Scott A; Maggin, Daniel M; Tomasula, Jessica L

    2014-08-01

    A great deal of research over the past decade has examined the appropriateness of curriculum-based measurement of oral reading (R-CBM) in universal screening. Multiple researchers have meta-analyzed available correlational evidence, yielding support for the interpretation of R-CBM as an indicator of general reading proficiency. In contrast, researchers have yet to synthesize diagnostic accuracy evidence, which pertains to the defensibility of the use of R-CBM for screening purposes. The overall purpose of this research was to therefore conduct the first meta-analysis of R-CBM diagnostic accuracy research. A systematic search of the literature resulted in the identification of 34 studies, including 20 peer-reviewed articles, 7 dissertations, and 7 technical reports. Bivariate hierarchical linear models yielded generalized estimates of diagnostic accuracy statistics, which predominantly exceeded standards for acceptable universal screener performance. For instance, when predicting criterion outcomes within a school year (≤9 months), R-CBM sensitivity ranged between .80 and .83 and specificity ranged between .71 and .73. Multiple moderators of R-CBM diagnostic accuracy were identified, including the (a) R-CBM cut score used to define risk, (b) lag in time between R-CBM and criterion test administration, and (c) percentile rank corresponding to the criterion test cut score through which students were identified as either truly at risk or not at risk. Follow-up analyses revealed substantial variability of extracted cut scores within grade and time of year (i.e., fall, winter, and spring). This result called into question the inflexible application of a single cut score across contexts and suggested the potential necessity of local cut scores. Implications for practices, directions for future research, and limitations are discussed. PMID:25107410

  16. Personal Verification/Identification via Analysis of the Peripheral ECG Leads: Influence of the Personal Health Status on the Accuracy.

    Science.gov (United States)

    Jekova, Irena; Bortolan, Giovanni

    2015-01-01

    Traditional means for identity validation (PIN codes, passwords), and physiological and behavioral biometric characteristics (fingerprint, iris, and speech) are susceptible to hacker attacks and/or falsification. This paper presents a method for person verification/identification based on correlation of present-to-previous limb ECG leads: I (r I), II (r II), calculated from them first principal ECG component (r PCA), linear and nonlinear combinations between r I, r II, and r PCA. For the verification task, the one-to-one scenario is applied and threshold values for r I, r II, and r PCA and their combinations are derived. The identification task supposes one-to-many scenario and the tested subject is identified according to the maximal correlation with a previously recorded ECG in a database. The population based ECG-ILSA database of 540 patients (147 healthy subjects, 175 patients with cardiac diseases, and 218 with hypertension) has been considered. In addition a common reference PTB dataset (14 healthy individuals) with short time interval between the two acquisitions has been taken into account. The results on ECG-ILSA database were satisfactory with healthy people, and there was not a significant decrease in nonhealthy patients, demonstrating the robustness of the proposed method. With PTB database, the method provides an identification accuracy of 92.9% and a verification sensitivity and specificity of 100% and 89.9%. PMID:26568954

  17. Personal Verification/Identification via Analysis of the Peripheral ECG Leads: Influence of the Personal Health Status on the Accuracy

    Directory of Open Access Journals (Sweden)

    Irena Jekova

    2015-01-01

    Full Text Available Traditional means for identity validation (PIN codes, passwords, and physiological and behavioral biometric characteristics (fingerprint, iris, and speech are susceptible to hacker attacks and/or falsification. This paper presents a method for person verification/identification based on correlation of present-to-previous limb ECG leads: I (rI, II (rII, calculated from them first principal ECG component (rPCA, linear and nonlinear combinations between rI, rII, and rPCA. For the verification task, the one-to-one scenario is applied and threshold values for rI, rII, and rPCA and their combinations are derived. The identification task supposes one-to-many scenario and the tested subject is identified according to the maximal correlation with a previously recorded ECG in a database. The population based ECG-ILSA database of 540 patients (147 healthy subjects, 175 patients with cardiac diseases, and 218 with hypertension has been considered. In addition a common reference PTB dataset (14 healthy individuals with short time interval between the two acquisitions has been taken into account. The results on ECG-ILSA database were satisfactory with healthy people, and there was not a significant decrease in nonhealthy patients, demonstrating the robustness of the proposed method. With PTB database, the method provides an identification accuracy of 92.9% and a verification sensitivity and specificity of 100% and 89.9%.

  18. ACCURACY ANALYSIS OF WRIGHT'S CAPABILITY INDEX "CS" AND MODELLING NON-NORMAL DATA USING STATISTICAL SOFTWARE-A COMPARATIVE STUDY

    Directory of Open Access Journals (Sweden)

    Yerriswamy Wooluru

    2015-06-01

    Full Text Available Process Capability Indices (PCI has been widely used as a means of summarizing process performance relative to set of specification limits. The proper use of process capability indices are based on some assumptions which may not be true always. Therefore, sometime whether the process capability indices can truly reflect the performance of a process is questionable. Most of PCIs, including Cp, Cpk, Cpm and Cpmk, neglect the changes in the shape of the distribution, which is an important indicator of problems in skewness-prone processes. Wright proposed a process capability index 'Cs' to detect shape changes in a process due to skewness by incorporating a penalty for skewness. In this paper, the effect of skewness on assessment of accuracy of Wright's capability index Cs is studied and comparison is made with Cp, Cpk, Cpm and Cpmk indices when the distribution of the quality characteristic (spring force considered is skewed slightly. This paper also discusses how modelling the non normal data using statistical software and results were compared with other methods.

  19. Analysis on Velocity Measuring Accuracy of RDI ADCP%两种型号RDI ADCP测速精度分析

    Institute of Scientific and Technical Information of China (English)

    李占桥; 田志光; 吴宝勤

    2012-01-01

    关于多普勒海流剖面仪(ADCP)测速精度一直没有明确认识,基于差分ADCP底跟踪船速与差分GPS测量船速进行比较,统计分析了ADCP测速精度,并利用直线拟合的方法,给出了两种型号RDI ADCP的测速误差.结果表明,不同航速下38kHz ADCP测速精度较高,且不受船速影响;300kHz ADCP底跟踪船速始终大于GPS船速,误差随船速呈线性增加.%There was no explicit understanding about ADCP' s velocity measuring accuracy. This paper compared two ships' velocities which were mersured by ADCP-track and GPS, and then the paper analyzed the ADCP' s velocity measuring accuracy under different ship velocities. The paper draws up the velocity measuring errors of the two types of RDI ADCP based on the method of straight line matching. The result indicates that the 38kHz ADCP' s velocity measuring accuracy was better and it is not influenced by ship-velocity; while the 300kHz ADCP' s track-velocity is faster than GPS-velocity all the time, and the error is increasing linearly with ship-velocity.

  20. Expected accuracy in a measurement of the CKM angle alpha using a Dalitz plot analysis of B0 ---> rho pi decays in the BTeV project

    Energy Technology Data Exchange (ETDEWEB)

    Shestermanov, K.E.; Vasiliev, A.N; /Serpukhov, IHEP; Butler, J.; Derevschikov, A.A.; Kasper, P.; Kiselev, V.V.; Kravtsov, V.I.; Kubota, Y.; Kutschke, R.; Matulenko, Y.A.; Minaev, N.G.; /Serpukhov, IHEP /Fermilab /Minnesota U. /Syracuse U. /INFN, Milan

    2005-12-01

    A precise measurement of the angle {alpha} in the CKM triangle is very important for a complete test of Standard Model. A theoretically clean method to extract {alpha} is provided by B{sup 0} {yields} {rho}{pi} decays. Monte Carlo simulations to obtain the BTeV reconstruction efficiency and to estimate the signal to background ratio for these decays were performed. Finally the time-dependent Dalitz plot analysis, using the isospin amplitude formalism for tre and penguin contributions, was carried out. It was shown that in one year of data taking BTeV could achieve an accuracy on {alpha} better than 5{sup o}.

  1. Bayesian meta-analysis of test accuracy in the absence of a perfect reference test applied to bone scintigraphy for the diagnosis of complex regional pain syndrome.

    Science.gov (United States)

    Held, Ulrike; Brunner, Florian; Steurer, Johann; Wertli, Maria M

    2015-11-01

    There is conflicting evidence about the accuracy of bone scintigraphy (BS) for the diagnosis of complex regional pain syndrome 1 (CRPS 1). In a meta-analysis of diagnostic studies, the evaluation of test accuracy is impeded by the use of different imperfect reference tests. The aim of our study is to summarize sensitivity and specificity of BS for CRPS 1 and to identify factors to explain heterogeneity. We use a hierarchical Bayesian approach to model test accuracy and threshold, and we present different models accounting for the imperfect nature of the reference tests, and assuming conditional dependence between BS and the reference test results. Further, we include disease duration as explanatory variable in the model. The models are compared using summary ROC curves and the deviance information criterion (DIC). Our results show that those models which account for different imperfect reference tests with conditional dependence and inclusion of the covariate are the ones with the smallest DIC. The sensitivity of BS was 0.87 (95% credible interval 0.73-0.97) and the overall specificity was 0.87 (0.73-0.95) in the model with the smallest DIC, in which missing values of the covariate are imputed within the Bayesian framework. The estimated effect of duration of symptoms on the threshold parameter was 0.17 (-0.25 to 0.57). We demonstrate that the Bayesian models presented in this paper are useful to address typical problems occurring in meta-analysis of diagnostic studies, including conditional dependence between index test and reference test, as well as missing values in the study-specific covariates. PMID:26479506

  2. Diagnostic accuracy of stroke volume variation measured with uncalibrated arterial waveform analysis for the prediction of fluid responsiveness in patients with impaired left ventricular function: a prospective, observational study.

    Science.gov (United States)

    Montenij, L J; Sonneveld, J P C; Nierich, A P; Buhre, W F; de Waal, E E C

    2016-08-01

    Uncalibrated arterial waveform analysis enables dynamic preload assessment in a minimally invasive fashion. Evidence about the validity of the technique in patients with impaired left ventricular function is scarce, while adequate cardiac preload assessment would be of great value in these patients. The aim of this study was to investigate the diagnostic accuracy of stroke volume variation (SVV) measured with the FloTrac/Vigileo™ system in patients with impaired left ventricular function. In this prospective, observational study, 22 patients with a left ventricular ejection fraction of 40 % or less undergoing elective coronary artery bypass grafting were included. Patients were considered fluid responsive if cardiac output increased with 15 % or more after volume loading (7 ml kg(-1) ideal body weight). The following variables were calculated: area under the receiver operating characteristics (ROC) curve, ideal cut-off value for SVV, sensitivity, specificity, positive and negative predictive values, and overall accuracy. In addition, SVV cut-off points to obtain 90 % true positive and 90 % true negative predictions were determined. ROC analysis revealed an area under the curve of 0.70 [0.47; 0.92]. The ideal SVV cut-off value was 10 %, with a corresponding sensitivity and specificity of 56 and 69 % respectively. Overall accuracy was 64 %, positive and negative predictive values were 69 and 56 % respectively. SVV values to obtain more than 90 % true positive and negative predictions were 16 and 6 % respectively. The ability of uncalibrated arterial waveform analysis SVV to predict fluid responsiveness in patients with impaired LVF was low. PMID:26227160

  3. Systematic reviews of diagnostic test accuracy

    DEFF Research Database (Denmark)

    Leeflang, Mariska M G; Deeks, Jonathan J; Gatsonis, Constantine;

    2008-01-01

    More and more systematic reviews of diagnostic test accuracy studies are being published, but they can be methodologically challenging. In this paper, the authors present some of the recent developments in the methodology for conducting systematic reviews of diagnostic test accuracy studies......-operating characteristic or the bivariate model for the data analysis. Challenges that remain are the poor reporting of original diagnostic test accuracy studies and difficulties with the interpretation of the results of diagnostic test accuracy research....

  4. The detection accuracy of cone beam CT for osseous defects of the temporomandibular joint: a systematic review and meta-analysis

    Science.gov (United States)

    Ma, Ruo-han; Yin, Shuang; Li, Gang

    2016-01-01

    The purpose of this review was to evaluate whether cone-beam computed tomography (CBCT) is reliable for the detection of bone changes of the temporomandibular joint (TMJ). Studies collected from the PubMed, Web of Science, Cochrane Library, ScienceDirect, Embase, Wanfang and CNKI databases were searched, and the publishing time was limited from January 1990 to December 2015. Eight studies (23 experimental research groups) were eventually included for further analysis. The pooled sensitivity was 0.67 and the pooled specificity was 0.87, which leads to a relatively large area (0.84) under the Receiver Operating Characteristic (ROC) curve. The related pooled positive likelihood ratio (+LR) and the pooled negative likelihood ratio (−LR) were 5.2 and 0.38, respectively. The subgroup analysis was conducted for four subgroups categorized by voxel size (≤0.2; >0.2, ≤0.3; >0.3, ≤0.4; >0.4, and ≤0.5 (mm)), and the “>0.4, ≤0.5” subgroup had a higher pooled sensitivity and pooled specificity than the other groups. The present study demonstrates that CBCT has a relatively high diagnostic accuracy for TMJ bone changes, although its reliability is limited. Voxel size did not play a role in the accuracy of CBCT. PMID:27708375

  5. Assessing the Classification Accuracy of Early Numeracy Curriculum-Based Measures Using Receiver Operating Characteristic Curve Analysis

    Science.gov (United States)

    Laracy, Seth D.; Hojnoski, Robin L.; Dever, Bridget V.

    2016-01-01

    Receiver operating characteristic curve (ROC) analysis was used to investigate the ability of early numeracy curriculum-based measures (EN-CBM) administered in preschool to predict performance below the 25th and 40th percentiles on a quantity discrimination measure in kindergarten. Areas under the curve derived from a sample of 279 students ranged…

  6. Competitive PCR-DGGE analysis of bacterial mixtures an internal standard and an appraisal of template enumeration accuracy

    NARCIS (Netherlands)

    Brüggemann, J.; Stephen, J.R.; Chang, Y.J.; MacNaughton, S.J.; Kowalchuk, G.A.; Kline, E.; White, D.C.

    2000-01-01

    Analysis of polymerase chain reaction (PCR) amplified 16S rDNA fragments from environmental samples by denaturing gradients of chemicals or heat [denaturing gradient gel electrophoresis (DGGE) and thermal gradient gel electrophoresis (TGGE)] within polyacrylamide gels is a popular tool in microbial

  7. Diagnostic accuracy of posterior pole asymmetry analysis parameters of spectralis optical coherence tomography in detecting early unilateral glaucoma

    Directory of Open Access Journals (Sweden)

    Paaraj Dave

    2015-01-01

    Full Text Available Purpose: To report the diagnostic ability of posterior pole asymmetry analysis (PPAA parameters of spectralis optical coherence tomography (OCT in detecting early unilateral glaucoma. Methods: A prospective, cross-sectional study which included 80 eyes of 80 normal subjects and 76 eyes of 76 patients with unilateral early primary open-angle glaucoma by Hodapp-Anderson-Parrish classification. All subjects were of age more than 18 years, best-corrected visual acuity 20/40 or better, and a refractive error within ± 5 diopter (D sphere and ± 3 D cylinder. Control subjects had a normal ocular examination, intraocular pressure (IOP <22 mmHg, no past history of high IOP, no family history of glaucoma, normal optic disc morphology, and visual field in both eyes. One eye of the control subject was randomly included. All eyes underwent OCT for retinal nerve fiber layer (RNFL analysis and PPAA. The number of continuous black squares was noted in the asymmetry analysis (right-left + hemisphere asymmetry. The area under curve (AUC was calculated for all OCT parameters. Results: The best value for AUC for RNFL analysis was 0.858 for the inferotemporal quadrant thickness. This was similar to the best value for AUC for PPAA which was 0.833 for the inferior macular thickness parameter (P = 0.5. The AUC for the right-left and the hemisphere asymmetry part of PPAA was 0.427 and 0.499, respectively. Conclusion: The macular thickness PPAA parameters were equally good as the RNFL parameters. However, the asymmetry analysis parameters performed poorly and need further refinement before its use in early unilateral glaucoma diagnosis.

  8. The Impact of Financial Crisis on the Predictability of the Stock Markets of PIGS Countries – Comparative Study of Prediction Accuracy of Technical Analysis and Neural Networks

    Directory of Open Access Journals (Sweden)

    Katarína Hiľovská

    2011-09-01

    Full Text Available To a degree the financial crisis influenced all European countries but the most affected are the PIGS (Portugal, Ireland, Greece and Spain. We investigated the effect of the financial crisis on the prediction accuracy of artificial neural networks on the Portuguese, Irish, Athens and Madrid Stock Exchange. We applied three-layered feed-forward neural networks with backpropagation algorithm to forecast the next day prices and we compared the paper returns achieved before and after the recent financial crisis. This method failed in forecasting the direction of the next day price movement but performed well in absolute price changes. However, it achieved better results than the strategy based on technical analysis in the period before the crisis. On the other hand, technical analysis performed better during the crisis.

  9. An analysis and study of decision tree induction operating under adaptive mode to enhance accuracy and uptime in a dataset introduced to spontaneous variation in data attributes

    Directory of Open Access Journals (Sweden)

    Uttam Chauhan

    2011-01-01

    Full Text Available Many methods exist for the purpose of classification of an unknown dataset. Decision tree induction is one of the well-known methods for classification. Decision tree method operates under two different modes: nonadaptive and adaptive mode. The non adaptive mode of operation is applied when the data set is completely mature and available or the data set is static and their will be no changes in dataset attributes. However when the dataset is likely to have changes in the values and attributes leading to fluctuation i.e., monthly, quarterly or annually, then under the circumstances decision tree method operating under adaptive mode needs to be applied, as the conventional non-adaptive method fails, as it needs to be applied once again starting from scratch on the augmented dataset. This makes things expensive in terms of time and space. Sometimes attributesare added into the dataset, at the same time number of records also increases. This paper mainly studies the behavioral aspects of classification model particularly, when number of attr bute in dataset increase due to spontaneous changes in the value(s/attribute(s. Our investigative studies have shown that accuracy of decision tree model can be maintained when number of attributes including class increase in dataset which increases thenumber of records as well. In addition, accuracy also can be maintained when number of values increase in class attribute of dataset. The way Adaptive mode decision tree method operates is that it reads data instance by instance and incorporates the same through absorption to the said model; update the model according to valueof attribute particular and specific to the instance. As the time required to updating decision tree can be less than introducing it from scratch, thus eliminating the problem of introducing decision tree repeatedly from scratch and at the same time gaining upon memory and time.

  10. Accuracy of computed tomography perfusion in detecting delayed cerebral ischemia following aneurysmal subarachnoid hemorrhage: A meta-analysis

    Directory of Open Access Journals (Sweden)

    Haogeng Sun

    2013-01-01

    Full Text Available Background and Purpose: In recent years, significant literature shows that computed tomography perfusion (CTP can provide sufficient information on cerebral hemodynamics and effectively indicate delayed cerebral ischemia (DCI before the development of infarction. We aimed at performing a meta-analysis to provide a more full and accurate evaluation of CTP and CTP parameters in detecting DCI in patients with aneurysmal subarachnoid hemorrhage. Materials and Methods: We searched the PubMed, MedLine, Embase and Cochrane databases for analysis published from February 2005 to February 2013. We extracted CTP parameters, including cerebral blood volume (CBV, cerebral blood flow (CBF, mean transit time (MTT, time to peak (TTP, interhemispheric ratios for CBV and CBF and interhemispheric differences for MTT and TTP. Pooled estimates of sensitivity, specificity, positive likelihood ratio (PLR, negative likelihood ratio (NLR, diagnostic odds ratio (DOR and the summary receiver-operating characteristic curve were determined. Results: Four research studies are met the inclusion criteria for the analysis. The pooled sensitivity, specificity, PLR, NLR and DOR of CTP for detecting the DCI were 82%, 82%, 4.56, 0.22 and 20.96, respectively. Through the evaluation of absolute CTP parameters, CBF and MTT showed diagnostic value for DCI, but CBF and TTP did not. Moreover, CBF ratio, MTT difference and TTP difference showed more diagnostic value than CBV ratio in DCI detection by the assessment of relative CTP parameters. Conclusions: As a non-invasive and short time consuming screening method, CTP own a high diagnostic value for the detection of DCI after aneurysm rupture.

  11. Diagnostic accuracy of in-stent coronary restenosis detection with multislice spiral computed tomography: a meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hamon, Michele [University Hospital of Caen, Department of Radiology, 14033 Caen Cedex, Normandy (France); Champ-Rigot, Laure; Riddell, John W. [University Hospital of Caen, Department of Cardiology, 14033 Caen Cedex, Normandy (France); Morello, Remy [University Hospital of Caen, Department of Statistics, 14033 Caen Cedex, Normandy (France); Hamon, Martial [University Hospital of Caen, Department of Cardiology, 14033 Caen Cedex, Normandy (France); Institut Pasteur de Lille, INSERM 744, Lille (France); Centre Hospitalier Universitaire de Caen, Service des Maladies du Coeur et des Vaisseaux, 14033 Caen Cedex, Normandy (France)

    2008-02-15

    This study was designed to define the current role of multislice spiral computed tomography (MSCT) for the diagnosis of coronary in-stent restenosis using a meta-analytic process. Restenosis remains a limitation after coronary stent implantation and contributes to a substantial number of coronary re-assessments by conventional invasive coronary angiography (CA). We identified 15 studies (807 patients) evaluating in-stent restenosis by means of both MSCT ({>=}16 slices) and conventional CA until February 2007. After data extraction the analysis was performed according to a random-effects model. The analysis pooled the results from 15 studies with a total of 1,175 stents. A substantial number of unassessable stents (13%) were excluded from the analysis underscoring the shortcomings of MSCT. With this major limitation the diagnostic performance of MSCT for in-stent restenosis detection can be summarized as follows: the sensitivity and specificity were 84% [95% confidence interval (CI) 77-89%] and 91% (95% CI 89-93%), respectively, with positive and negative likelihood ratios of 12.2 (95% CI 6.6-22.6) and 0.23 (95% CI 0.17-0.31), respectively, and with a diagnostic odds ratio of 67.9 (95% CI 34.4-134.1). MSCT has shortcomings difficult to overcome in daily practice for in-stent restenosis detection and continues to have moderately high sensitivity and specificity. The diagnostic role of this emerging technology as an alternative to CA for in-stent restenosis detection remains limited. (orig.)

  12. An Analysis of the Accuracy of Electromechanical Eigenvalue Calculations Based on Instantaneous Power Waveforms Recorded in a Power Plant

    Directory of Open Access Journals (Sweden)

    Piotr Pruski

    2013-12-01

    Full Text Available The paper presents the results of calculating the eigenvalues (associated with electromechanical phenomena of the state matrix of the Polish Power System model on the basis of analysis of simulated and measured instantaneous power disturbance waveforms of generating units in Łaziska Power Plant. The method for electromechanical eigenvalue calculations used in investigations consists in approximation of the instantaneous power swing waveforms in particular generating units with the use of the waveforms being a superposition of the modal components associated with the searched eigenvalues and their participation factors. The hybrid optimisation algorithm consisting of the genetic and gradient algorithms was used for computations.

  13. RELAP5/MOD3.2 re-analysis and accuracy quantification of LOFT experiment L2-5

    Energy Technology Data Exchange (ETDEWEB)

    Petruzzi, A.; Giannotti, W.; D' Auria, F. [Universita di Pisa, Dipartimento di Ingegneria Meccanica, Nucleare e della Produzione, Pisa (Italy)]. E-mail: axp46@psu.edu; w.giannotti@ing.unipi.it; dauria@ing.unipi.it

    2004-07-01

    The paper presents the activity performed at University of Pisa in the framework of the participation to the Phase II of the BEMUSE (Best Estimate Methods - Uncertainty and Sensitivity Evaluation) Programme. This activity has been promoted by the Working Group on Accident Management and Analysis (GAMA) and endorsed by the Committee on the Safety of Nuclear Installations (CSNI). The scope of the Programme is to perform Large Break Loss-Of-Coolant Accident (LBLOCA) analyses making reference to experimental data and to a Nuclear Power Plant (NPP) in order to address the issue of 'the capabilities of computational tools' including scaling/uncertainty analysis. The justification for such an activity comes from the consideration that a wide spectrum of uncertainty methods applied to Best Estimate codes exist and are used in research laboratories, but their practicability and/or validity is not sufficiently established to support general use of the codes and acceptance by industry and safety authorities. The consideration of the Best Estimate codes and uncertainty evaluation for Design Basis Accident (DBA), by itself, shows the safety significance of the proposed activity. (author)

  14. Diagnostic accuracy of the aspartate aminotransferase-to-platelet ratio index for the prediction of hepatitis B-related fibrosis: a leading meta-analysis

    Directory of Open Access Journals (Sweden)

    Jin Wenwen

    2012-02-01

    Full Text Available Abstract Background The aspartate aminotransferase-to-platelet ratio index (APRI, a tool with limited expense and widespread availability, is a promising noninvasive alternative to liver biopsy for detecting hepatic fibrosis. The objective of this study was to systematically review the performance of the APRI in predicting significant fibrosis and cirrhosis in hepatitis B-related fibrosis. Methods Areas under summary receiver operating characteristic curves (AUROC, sensitivity and specificity were used to examine the accuracy of the APRI for the diagnosis of hepatitis B-related significant fibrosis and cirrhosis. Heterogeneity was explored using meta-regression. Results Nine studies were included in this meta-analysis (n = 1,798. Prevalence of significant fibrosis and cirrhosis were 53.1% and 13.5%, respectively. The summary AUCs of the APRI for significant fibrosis and cirrhosis were 0.79 and 0.75, respectively. For significant fibrosis, an APRI threshold of 0.5 was 84% sensitive and 41% specific. At the cutoff of 1.5, the summary sensitivity and specificity were 49% and 84%, respectively. For cirrhosis, an APRI threshold of 1.0-1.5 was 54% sensitive and 78% specific. At the cutoff of 2.0, the summary sensitivity and specificity were 28% and 87%, respectively. Meta-regression analysis indicated that the APRI accuracy for both significant fibrosis and cirrhosis was affected by histological classification systems, but not influenced by the interval between Biopsy & APRI or blind biopsy. Conclusion Our meta-analysis suggests that APRI show limited value in identifying hepatitis B-related significant fibrosis and cirrhosis.

  15. Maintaining accuracy of cellular Yule-Nielsen spectral Neugebauer models for different ink cartridges using principal component analysis.

    Science.gov (United States)

    Wang, Binyu; Xu, Haisong; Luo, M Ronnier; Guo, Jinyi

    2011-07-01

    The replacement of used-up ink cartridges is unavoidable, but it makes the existing characterization model far from accurate, while recharacterization is labor intensive. In this study, we propose a new correction method for cellular Yule-Nielsen spectral Neugebauer (CYNSN) models based on principal component analysis (PCA). First, a small set of correction samples are predicted, printed using new ink cartridges, and then measured. Second, the link between the predicted and measured reflectance weights, generated by PCA, is determined. The experimental results show that the proposed method provides a significant and robust improvement, since not only the color change between original and new inks but also the systemic error of CYNSN modelsis taken into account in the method.

  16. Accuracy assessment on the analysis of unbound drug in plasma by comparing traditional centrifugal ultrafiltration with hollow fiber centrifugal ultrafiltration and application in pharmacokinetic study.

    Science.gov (United States)

    Zhang, Lin; Zhang, Zhi-Qing; Dong, Wei-Chong; Jing, Shao-Jun; Zhang, Jin-Feng; Jiang, Ye

    2013-11-29

    In present study, accuracy assessment on the analysis of unbound drug in plasma was made by comparing traditional centrifugal ultrafiltration (CF-UF) with hollow fiber centrifugal ultrafiltration (HFCF-UF). We used metformin (MET) as a model drug and studied the influence of centrifugal time, plasma condition and freeze-thaw circle times on the ultrafiltrate volume and related effect on the measurement of MET. Our results demonstrated that ultrafiltrate volume was a crucial factor which influenced measurement accuracy of unbound drug in plasma. For traditional CF-UF, the ultrafiltrate volume cannot be well-controlled due to a series of factors. Compared with traditional CF-UF, the ultrafiltrate volume by HFCF-UF can be easily controlled by the inner capacity of the U-shaped hollow fiber inserted into the sample under enough centrifugal force and centrifugal time, which contributes to a more accurate measurement. Moreover, the developed HFCF-UF method achieved a successful application in real plasma samples and exhibited several advantages including high precision, extremely low detection limit and perfect recovery. The HFCF-UF method offers the advantage of highly satisfactory performance in addition to being simple and fast in pretreatment, with these characteristics being consistent with the practicability requirements in current scientific research.

  17. Target Price Accuracy

    Directory of Open Access Journals (Sweden)

    Alexander G. Kerl

    2011-04-01

    Full Text Available This study analyzes the accuracy of forecasted target prices within analysts’ reports. We compute a measure for target price forecast accuracy that evaluates the ability of analysts to exactly forecast the ex-ante (unknown 12-month stock price. Furthermore, we determine factors that explain this accuracy. Target price accuracy is negatively related to analyst-specific optimism and stock-specific risk (measured by volatility and price-to-book ratio. However, target price accuracy is positively related to the level of detail of each report, company size and the reputation of the investment bank. The potential conflicts of interests between an analyst and a covered company do not bias forecast accuracy.

  18. Rethinking Empathic Accuracy

    OpenAIRE

    Meadors, Joshua

    2014-01-01

    The present study is a methodological examination of the implicit empathic accuracy measure introduced by Zaki, Ochsner, and Bolger (2008). Empathic accuracy (EA) is defined as the ability to understand another person's thoughts and feelings (Ickes, 1993). Because this definition is similar to definitions of cognitive empathy (e.g., Shamay-Tsoory, 2011) and because affective empathy does not appear to be related to empathic accuracy (Zaki et al., 2008), the Basic Empathy Scale--which measures...

  19. The Truth about Accuracy

    OpenAIRE

    Buekens, Filip; Truyen, Frederik

    2014-01-01

    When we evaluate the outcomes of investigative actions as justified or unjustified, good or bad, rational or irrational, we make, in a broad sense of the term, evaluative judgments about them. We look at operational accuracy as a desirable and evaluable quality of the outcomes and explore how the concepts of accuracy and precision, on the basis of insights borrowed from pragmatics and measurement theory, can be seen to do useful work in epistemology. Operational accuracy (but not metaphysical...

  20. 风电功率预测准确性分析%Analysis of Accuracy of Wind Power Forecasting

    Institute of Scientific and Technical Information of China (English)

    苏赞; 王维庆; 王健波; 常喜强; 张新燕

    2012-01-01

    Wind power industry is developing rapidly, and has become an important field of energy development. Because the capacity of wind power connecting to grid increases rapidly, the relationship of wind power and power system is more and more close, so it must be considered the changes of wind power output what the fluctuant and intermittent of wind cause bring the bad influence to power quality of power system, the safe and stable operation and economic benefit. Therefore, wind power prediction would have important practical significance. Firstly, classification and methods of the wind power output forecast and wind speed are discussed, and then this paper review the research situation of the wind power forecasting technology at home and abroad, finally according to our country present stage, what cause the errors of wind power forecasting were introduced, and puts forward some advice to solve them.%摘要风电并网容量迅猛增加,风电与系统之间的联系越来越密切,必须考虑风能的波动性和问歇性引起风电出力的变化给电力系统电能质量、安全稳定运行和经济效益带来的不利影响。因此,进行风电功率预测具有重要的现实意义。首先对风速和风电出力预测的分类和方法进行了探讨,然后简要综述了国内外风功率预测技术的研究现状,最后针对我国现阶段风电功率预测产生误差的原因进行了阐述并提出了建议。

  1. SU-E-T-248: Near Real-Time Analysis of Radiation Delivery and Imaging, Accuracy to Ensure Patient Safety

    Energy Technology Data Exchange (ETDEWEB)

    Wijesooriya, K; Seitter, K; Desai, V; Read, P; Larner, J [University of Virginia Health Systems, Charlottesville, VA (United States)

    2014-06-01

    Purpose: To develop and optimize an effective software method for comparing planned to delivered control point machine parameters for all VARIAN TrueBeam treatments so as to permit (1) assessment of a large patient pool throughout their treatment course to quantify treatment technique specific systematic and random uncertainty of observables, (2) quantify the site specific daily imaging shifts required for target alignment, and (3) define tolerance levels for mechanical parameters and imaging parameters based on statistical analysis data gathered, and the dosimetric impact of variations. Methods: Treatment and imaging log files were directly compared to plan parameters for Eclipse and Pinnacle planned treatments via 3D, IMRT, control point, RapidArc, and electrons. Each control point from all beams/arcs (7984) for all fractions (1940) of all patients treated over six months were analyzed. At each control point gantry angle, collimator angle, couch angle, jaw positions, MLC positions, MU were compared. Additionally per-treatment isocenter shifts were calculated. Results were analyzed as a whole in treatment type subsets: IMRT, 3D, RapidArc; and in treatment site subsets: brain, chest/mediastinum, esophagus, H and N, lung, pelvis, prostate. Results: Daily imaging isocenter shifts from initial external tattoo alignment were dependent on the treatment site with < 0.5 cm translational shifts for H and N, Brain, and lung SBRT, while pelvis, esophagus shifts were ∼1 cm. Mechanical delivery parameters were within tolerance levels for all sub-beams. The largest variations were for RapidArc plans: gantry angle 0.11±0.12,collimator angle 0.00±0.00, jaw positions 0.48±0.26, MLC leaf positions 0.66±0.08, MU 0.14±0.34. Conclusion: Per-control point validation reveals deviations between planned and delivered parameters. If used in a near real-time error checking system, patient safety can be improved by equipping the treatment delivery system with additional forcing

  2. Diagnostic accuracy of {sup 18}F-FDG-PET and PET/CT in patients with Ewing sarcoma family tumours: a systematic review and a meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Treglia, Giorgio [Institute of Nuclear Medicine, Catholic University of the Sacred Heart, Department of Bioimaging and Radiological Sciences, Rome (Italy); Institute of Nuclear Medicine, Positron Emission Tomography Centre, Catholic University of the Sacred Heart, Department of Bioimaging and Radiological Sciences, Rome (Italy); Salsano, Marco; Stefanelli, Antonella; Mattoli, Maria Vittoria; Giordano, Alessandro [Institute of Nuclear Medicine, Catholic University of the Sacred Heart, Department of Bioimaging and Radiological Sciences, Rome (Italy); Bonomo, Lorenzo [Institute of Radiology, Catholic University of the Sacred Heart, Department of Bioimaging and Radiological Sciences, Rome (Italy)

    2012-03-15

    To systematically review and meta-analyse literature data on the diagnostic performance of fluorine-18-fluorodeoxyglucose (FDG) positron emission tomography (PET) and positron emission tomography/computed tomography (PET/CT) in patients with Ewing sarcoma family tumours (ESFT). PubMed/MEDLINE, Embase and Scopus databases were searched for articles that evaluated FDG-PET and PET/CT in patients with ESFT from inception to 31 May 2011. Studies that fulfilled the three following criteria were included in the systematic review: FDG-PET or PET/CT performed in patients with ESFT; articles about the diagnostic accuracy of FDG-PET and PET/CT; sample size of at least 10 patients with ESFT were included. Studies in which there were sufficient data to reassess sensitivity and specificity of FDG-PET or PET/CT in ESFT were included in the meta-analysis, excluding duplicate publications. Finally, pooled sensitivity, pooled specificity and area under the receiver operating characteristic (ROC) curve of FDG-PET or PET/CT in ESFT were calculated. We found 13 studies comprising a total of 342 patients with ESFT. The main findings of the studies included are presented. The meta-analysis of five selected studies provided these results about FDG-PET and PET/CT in ESFT: pooled sensitivity: 96% (95% confidence interval [CI] 91-99%); pooled specificity: 92% (95% CI 87-96%); area under the ROC curve: 0.97. With regard to the staging and restaging of patients with ESFT, the sensitivity, specificity and accuracy of FDG-PET and PET/CT are high; the combination of FDG-PET or PET/CT with conventional imaging is a valuable tool for the staging and restaging of ESFT and has a relevant impact on the treatment strategy plan. (orig.)

  3. Non-invasive prenatal diagnostic test accuracy for fetal sex using cell-free DNA a review and meta-analysis

    Directory of Open Access Journals (Sweden)

    Wright Caroline F

    2012-09-01

    Full Text Available Abstract Background Cell-free fetal DNA (cffDNA can be detected in maternal blood during pregnancy, opening the possibility of early non-invasive prenatal diagnosis for a variety of genetic conditions. Since 1997, many studies have examined the accuracy of prenatal fetal sex determination using cffDNA, particularly for pregnancies at risk of an X-linked condition. Here we report a review and meta-analysis of the published literature to evaluate the use of cffDNA for prenatal determination (diagnosis of fetal sex. We applied a sensitive search of multiple bibliographic databases including PubMed (MEDLINE, EMBASE, the Cochrane library and Web of Science. Results Ninety studies, incorporating 9,965 pregnancies and 10,587 fetal sex results met our inclusion criteria. Overall mean sensitivity was 96.6% (95% credible interval 95.2% to 97.7% and mean specificity was 98.9% (95% CI = 98.1% to 99.4%. These results vary very little with trimester or week of testing, indicating that the performance of the test is reliably high. Conclusions Based on this review and meta-analysis we conclude that fetal sex can be determined with a high level of accuracy by analyzing cffDNA. Using cffDNA in prenatal diagnosis to replace or complement existing invasive methods can remove or reduce the risk of miscarriage. Future work should concentrate on the economic and ethical considerations of implementing an early non-invasive test for fetal sex.

  4. Does simplicity compromise accuracy in ACS risk prediction? A retrospective analysis of the TIMI and GRACE risk scores.

    Directory of Open Access Journals (Sweden)

    Krishna G Aragam

    Full Text Available BACKGROUND: The Thrombolysis in Myocardial Infarction (TIMI risk scores for Unstable Angina/Non-ST-elevation myocardial infarction (UA/NSTEMI and ST-elevation myocardial infarction (STEMI and the Global Registry of Acute Coronary Events (GRACE risk scores for in-hospital and 6-month mortality are established tools for assessing risk in Acute Coronary Syndrome (ACS patients. The objective of our study was to compare the discriminative abilities of the TIMI and GRACE risk scores in a broad-spectrum, unselected ACS population and to assess the relative contributions of model simplicity and model composition to any observed differences between the two scoring systems. METHODOLOGY/PRINCIPAL FINDINGS: ACS patients admitted to the University of Michigan between 1999 and 2005 were divided into UA/NSTEMI (n = 2753 and STEMI (n = 698 subpopulations. The predictive abilities of the TIMI and GRACE scores for in-hospital and 6-month mortality were assessed by calibration and discrimination. There were 137 in-hospital deaths (4%, and among the survivors, 234 (7.4% died by 6 months post-discharge. In the UA/NSTEMI population, the GRACE risk scores demonstrated better discrimination than the TIMI UA/NSTEMI score for in-hospital (C = 0.85, 95% CI: 0.81-0.89, versus 0.54, 95% CI: 0.48-0.60; p<0.01 and 6-month (C = 0.79, 95% CI: 0.76-0.83, versus 0.56, 95% CI: 0.52-0.60; p<0.01 mortality. Among STEMI patients, the GRACE and TIMI STEMI scores demonstrated comparably excellent discrimination for in-hospital (C = 0.84, 95% CI: 0.78-0.90 versus 0.83, 95% CI: 0.78-0.89; p = 0.83 and 6-month (C = 0.72, 95% CI: 0.63-0.81, versus 0.71, 95% CI: 0.64-0.79; p = 0.79 mortality. An analysis of refitted multivariate models demonstrated a marked improvement in the discriminative power of the TIMI UA/NSTEMI model with the incorporation of heart failure and hemodynamic variables. Study limitations included unaccounted for confounders inherent to observational, single institution

  5. Classification Accuracy Is Not Enough

    DEFF Research Database (Denmark)

    Sturm, Bob L.

    2013-01-01

    different state-of-the-art MGR systems, that classification accuracy does not necessarily reflect the capacity of a system to recognize genre in musical signals. We argue that a more comprehensive analysis of behavior at the level of the music is needed to address the problem of MGR, and that measuring......A recent review of the research literature evaluating music genre recognition (MGR) systems over the past two decades shows that most works (81\\%) measure the capacity of a system to recognize genre by its classification accuracy. We show here, by implementing and testing three categorically...

  6. Improving Speaking Accuracy through Awareness

    Science.gov (United States)

    Dormer, Jan Edwards

    2013-01-01

    Increased English learner accuracy can be achieved by leading students through six stages of awareness. The first three awareness stages build up students' motivation to improve, and the second three provide learners with crucial input for change. The final result is "sustained language awareness," resulting in ongoing…

  7. Optical System Error Analysis of High Accuracy Star Trackers%高精度星敏感器光学系统误差分析

    Institute of Scientific and Technical Information of China (English)

    孙婷; 邢飞; 尤政

    2013-01-01

    在对影响星敏感器精度的误差源做出权重分析和比较的基础上,提出一种基于蒙特卡罗模拟的星敏感器精度误差分析方法,避免冗长和繁琐的理论推导,直观且系统地分析了星敏感器误差传播关系,建立星敏感器误差传播模型,为星敏感器的优化设计、标定补偿提供依据和准则,通过仿真验证误差传播模型及误差分析方法的准确性,为高精度星敏感器的设计制造提供重要基础和保证.%A synthetic error analysis approach is proposed in detail based on error source weight analysis and comparison of the star tracker using Monte Carlo method. It can avoid long and cumbersome theoretical derivation, which can provide error propagation relation of the star tracker intuitively and systematacially. The error propagation model can provide foundation and rule for optimization design, calibration and compensation of the star tracker. Simulation consequences prove that the systematic analysis is adequate and precise, which can provides important guarantee for design and manufacture of high accuracy star trackers.

  8. Seismic refraction analysis with high accuracy based on traveltime modeling; Basu keisan wo base to shita kussekiho jishin tansa kaiseki no koseidoka

    Energy Technology Data Exchange (ETDEWEB)

    Saito, H.; Hayashi, K. [OYO Corp., Tokyo (Japan)

    1996-05-01

    For the purpose of enhancing the efficiency of analytical processes so that those not equipped with high skill may perform a certain level of analysis and that analysis precision may be improved, some analytical techniques based on path calculation were examined. As the result, a flow of work has become feasible, wherein an early model is constructed by use of a tomography-assisted analysis to be accomplished automatedly and the result is then converted into a layer system with the velocity and thickness to be automatically corrected for the determination of the ultimate velocity layer section. Following this flow of work, almost all the parts of the work may be accomplished automatically once the travel time curve is completed. Furthermore, the calculated travel time obtained by this method can be easily compared with the observed travel time creating an opportunity to show the high reliability of this method, for this to be accepted as a standard for evaluating the accuracy of exploration. It has also been found that this method may be applied to more complicated structures which fail to satisfy the conditions for a structure to be treated by other methods such as `Hagiwara`s method.` 3 refs., 5 figs.

  9. 某机械臂运动精度分析及优化%Analysis and Optimization on Motion Accuracy of the Mechanical Arm

    Institute of Scientific and Technical Information of China (English)

    刘桂峰; 伍洁

    2011-01-01

    针对潜艇蓄电池日常维护保养工作困难,对设计的蓄电池自动维护保养装置进行了运动精度分析.通过对传动误差产生的原因分析入手,采取理论分析、数值计算和实验分析对比验证的方法,将理论计算所得到的误差结果与应用Matlab软件测得的实验数据进行比较分析,并提出了优化改进方案.%Based on the difficulty on submarine battery daily maintenance, analysis of motion accuracy is carried out about the maintenance equipment designed for storage battery, starting with the reason of transmission error, comparison between the error of theoretical calculation and experiment data obtained from calculation by Mallab through theoretical analysis, numerical calculation and experimental analysis, and optimization scheme is given.

  10. Accuracy in Spreadsheet Modelling Systems

    CERN Document Server

    Grossman, Thomas A

    2008-01-01

    Accuracy in spreadsheet modelling systems can be reduced due to difficulties with the inputs, the model itself, or the spreadsheet implementation of the model. When the "true" outputs from the system are unknowable, accuracy is evaluated subjectively. Less than perfect accuracy can be acceptable depending on the purpose of the model, problems with inputs, or resource constraints. Users build modelling systems iteratively, and choose to allocate limited resources to the inputs, the model, the spreadsheet implementation, and to employing the system for business analysis. When making these choices, users can suffer from expectation bias and diagnosis bias. Existing research results tend to focus on errors in the spreadsheet implementation. Because industry has tolerance for system inaccuracy, errors in spreadsheet implementations may not be a serious concern. Spreadsheet productivity may be of more interest.

  11. Increasing the number of thyroid lesions classes in microarray analysis improves the relevance of diagnostic markers.

    Directory of Open Access Journals (Sweden)

    Jean-Fred Fontaine

    Full Text Available BACKGROUND: Genetic markers for thyroid cancers identified by microarray analysis have offered limited predictive accuracy so far because of the few classes of thyroid lesions usually taken into account. To improve diagnostic relevance, we have simultaneously analyzed microarray data from six public datasets covering a total of 347 thyroid tissue samples representing 12 histological classes of follicular lesions and normal thyroid tissue. Our own dataset, containing about half the thyroid tissue samples, included all categories of thyroid lesions. METHODOLOGY/PRINCIPAL FINDINGS: Classifier predictions were strongly affected by similarities between classes and by the number of classes in the training sets. In each dataset, sample prediction was improved by separating the samples into three groups according to class similarities. The cross-validation of differential genes revealed four clusters with functional enrichments. The analysis of six of these genes (APOD, APOE, CLGN, CRABP1, SDHA and TIMP1 in 49 new samples showed consistent gene and protein profiles with the class similarities observed. Focusing on four subclasses of follicular tumor, we explored the diagnostic potential of 12 selected markers (CASP10, CDH16, CLGN, CRABP1, HMGB2, ALPL2, ADAMTS2, CABIN1, ALDH1A3, USP13, NR2F2, KRTHB5 by real-time quantitative RT-PCR on 32 other new samples. The gene expression profiles of follicular tumors were examined with reference to the mutational status of the Pax8-PPARgamma, TSHR, GNAS and NRAS genes. CONCLUSION/SIGNIFICANCE: We show that diagnostic tools defined on the basis of microarray data are more relevant when a large number of samples and tissue classes are used. Taking into account the relationships between the thyroid tumor pathologies, together with the main biological functions and pathways involved, improved the diagnostic accuracy of the samples. Our approach was particularly relevant for the classification of microfollicular adenomas.

  12. Diagnostic accuracy of sensitive or high-sensitive troponin on presentation for myocardial infarction: a meta-analysis and systematic review

    Directory of Open Access Journals (Sweden)

    Sethi A

    2014-07-01

    Full Text Available Ankur Sethi,1 Anurag Bajaj,2 Gurveen Malhotra,1 Rohit R Arora,1 Sandeep Khosla1 1Department of Medicine, Division of Cardiology, Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA; 2Department of Medicine, Wright Center of Graduate Medical Education, Scranton, PA, USA Background: Recently, high-sensitive troponin (hsTrop assays consistent with professional societies' recommendations became available. We aimed to summarize the evidence on the diagnostic accuracy of hsTrop on presentation. Methods: We searched electronic databases for studies evaluating the diagnostic accuracy of hsTrop in suspected acute coronary syndrome (ACS patients. Random effect meta-analyses and meta-regression were performed. Primary and secondary analyses were restricted to studies using conventional Trop and hsTrop in the reference standard, respectively. Results: Fifteen studies with a total of 8,628 patients met the inclusion criteria for the primary analysis. hsTrop T (Hoffman-La Roche Ltd and hsTrop I (Siemens had sensitivities of 0.89 (95% confidence interval [CI]: 0.86–0.91 and 0.90 (95% CI: 0.87–0.92 and specificities of 0.79 (95% CI: 0.77–0.80 and 0.89 (95% CI: 0.87–0.90, respectively. There was no statistically significant difference in the area under the curve between hsTrop (95% CI: 0.920 and conventional Trop (95% CI: 0.929 at the 99th percentile (P=0.62. hsTrop at the level of detection had a sensitivity of 0.97 (95% CI: 0.96–0.98 and a specificity of 0.41 (95% CI: 0.40–0.42. The studies using a cut-off at coefficient of variance <10% as opposed to the 99th percentile for the conventional assay used for diagnosis reported higher diagnostic accuracy (relative diagnostic odds ratio =2.13, P=0.02. Five studies were included in the secondary analysis; hsTrop T (Hoffman-La Roche Ltd had a sensitivity of 0.91 (95% CI: 0.89–0.93 and a specificity of 0.67 (95% CI: 0.63–0.70. There was significant heterogeneity among the

  13. Accuracy of non-invasive prenatal testing using cell-free DNA for detection of Down, Edwards and Patau syndromes: a systematic review and meta-analysis

    Science.gov (United States)

    Taylor-Phillips, Sian; Freeman, Karoline; Geppert, Julia; Agbebiyi, Adeola; Uthman, Olalekan A; Madan, Jason; Clarke, Angus; Quenby, Siobhan; Clarke, Aileen

    2016-01-01

    Objective To measure test accuracy of non-invasive prenatal testing (NIPT) for Down, Edwards and Patau syndromes using cell-free fetal DNA and identify factors affecting accuracy. Design Systematic review and meta-analysis of published studies. Data sources PubMed, Ovid Medline, Ovid Embase and the Cochrane Library published from 1997 to 9 February 2015, followed by weekly autoalerts until 1 April 2015. Eligibility criteria for selecting studies English language journal articles describing case–control studies with ≥15 trisomy cases or cohort studies with ≥50 pregnant women who had been given NIPT and a reference standard. Results 41, 37 and 30 studies of 2012 publications retrieved were included in the review for Down, Edwards and Patau syndromes. Quality appraisal identified high risk of bias in included studies, funnel plots showed evidence of publication bias. Pooled sensitivity was 99.3% (95% CI 98.9% to 99.6%) for Down, 97.4% (95.8% to 98.4%) for Edwards, and 97.4% (86.1% to 99.6%) for Patau syndrome. The pooled specificity was 99.9% (99.9% to 100%) for all three trisomies. In 100 000 pregnancies in the general obstetric population we would expect 417, 89 and 40 cases of Downs, Edwards and Patau syndromes to be detected by NIPT, with 94, 154 and 42 false positive results. Sensitivity was lower in twin than singleton pregnancies, reduced by 9% for Down, 28% for Edwards and 22% for Patau syndrome. Pooled sensitivity was also lower in the first trimester of pregnancy, in studies in the general obstetric population, and in cohort studies with consecutive enrolment. Conclusions NIPT using cell-free fetal DNA has very high sensitivity and specificity for Down syndrome, with slightly lower sensitivity for Edwards and Patau syndrome. However, it is not 100% accurate and should not be used as a final diagnosis for positive cases. Trial registration number CRD42014014947. PMID:26781507

  14. Accuracy of 18F-flurodeoxyglucose-positron emission tomography/computed tomography in the staging of newly diagnosed nasopharyngeal carcinoma: a systematic review and meta-analysis

    International Nuclear Information System (INIS)

    The specific role of 18F-flurodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) in staging of nasopharyngeal carcinoma (NPC) remains to be validated. A systematic review and meta-analysis were performed to assess the accuracy of staging FDG-PET/CT for newly diagnosed NPC. We searched various biomedical databases and conference proceedings for relevant studies. We determined the pooled sensitivities and specificities, diagnostic odds ratios (DOR) and constructed summary receiver operating characteristic (SROC) curves using the hierarchical regression model. 15 relevant studies including 851 patients were identified. Five addressed primary tumor (T), nine addressed regional lymph nodes (N) and seven addressed distant metastasis (M). The combined sensitivity estimate for FDG-PET/CT in T classification was 0.77 (95% confidence interval [CI] 0.59–0.95). For N classification, combined sensitivity was 0.84 (95% CI 0.76–0.91), specificity was 0.90 (95% CI 0.83–0.97), DOR was 82.4 (23.2–292.6) and Q*-index was 0.90. For M classification, the combined sensitivity estimate was 0.87 (95% CI 0.74–1.00), specificity was 0.98 (95% CI 0.96–1.00), DOR was 120.9 (43.0–340.0) and Q*-index was 0.89. FDG-PET/CT showed good accuracy in N and M but not T classification for newly diagnosed NPC. FDG-PET/CT, together with Magnetic resonance imaging (MRI) of the nasopharynx, should be part of the routine staging investigations

  15. 100% Classification Accuracy Considered Harmful: The Normalized Information Transfer Factor Explains the Accuracy Paradox

    OpenAIRE

    Valverde-Albacete, Francisco J.; Carmen Peláez-Moreno

    2014-01-01

    The most widely spread measure of performance, accuracy, suffers from a paradox: predictive models with a given level of accuracy may have greater predictive power than models with higher accuracy. Despite optimizing classification error rate, high accuracy models may fail to capture crucial information transfer in the classification task. We present evidence of this behavior by means of a combinatorial analysis where every possible contingency matrix of 2, 3 and 4 classes classifiers are dep...

  16. Relative accuracy and availability of an Irish National Database of dispensed medication as a source of medication history information: observational study and retrospective record analysis.

    LENUS (Irish Health Repository)

    Grimes, T

    2013-01-27

    WHAT IS KNOWN AND OBJECTIVE: The medication reconciliation process begins by identifying which medicines a patient used before presentation to hospital. This is time-consuming, labour intensive and may involve interruption of clinicians. We sought to identify the availability and accuracy of data held in a national dispensing database, relative to other sources of medication history information. METHODS: For patients admitted to two acute hospitals in Ireland, a Gold Standard Pre-Admission Medication List (GSPAML) was identified and corroborated with the patient or carer. The GSPAML was compared for accuracy and availability to PAMLs from other sources, including the Health Service Executive Primary Care Reimbursement Scheme (HSE-PCRS) dispensing database. RESULTS: Some 1111 medication were assessed for 97 patients, who were median age 74 years (range 18-92 years), median four co-morbidities (range 1-9), used median 10 medications (range 3-25) and half (52%) were male. The HSE-PCRS PAML was the most accurate source compared to lists provided by the general practitioner, community pharmacist or cited in previous hospital documentation: the list agreed for 74% of the medications the patients actually used, representing complete agreement for all medications in 17% of patients. It was equally contemporaneous to other sources, but was less reliable for male than female patients, those using increasing numbers of medications and those using one or more item that was not reimbursable by the HSE. WHAT IS NEW AND CONCLUSION: The HSE-PCRS database is a relatively accurate, available and contemporaneous source of medication history information and could support acute hospital medication reconciliation.

  17. 机器人装配精度分析的虚拟示教仿真%Virtual Teaching Simulation for Robot Assembly Accuracy Analysis

    Institute of Scientific and Technical Information of China (English)

    张征; 周宏甫; 刘斌

    2004-01-01

    In this paper, by teaching a 3D robot unit model and playing back to simulate the assembly process in a virtual assembly environment, errors in robot assembly are analyzed. The paper also presents a visualization method for analyzing accuracy of the robot assembly, and studies the influence of the spatial pose of a robot on the success rate of an axis-hole assembly, and accuracy of the robot teaching program in particular. Through integration of various errors and on the basis of assembly accuracy, tolerance of error sources can be reasonably distributed to meet the assembly accuracy requirement, therefore the planning of robot assembly unit can be improved.

  18. 宽角相机低空航测的精度分析%Accuracy Analysis of Low Altitude Photogrammetry with WideGangle Camera

    Institute of Scientific and Technical Information of China (English)

    林宗坚; 解斐斐; 苏国中

    2014-01-01

    Firstly,the relationship between the accuracy of low altitude aerial photogrammetry and the field angle of camera is made by a quantitative analysis from the theory.The conclusion that the low altitude photogrammetry should use wideGangle camera as much as possible is done.Then,the limitation of the single lens camera to expand field angle and the combined wideGangle camera existing on the market not suitable for light load of low altitude UAV (unmanned aerial vehicle)due to excessive weight are pointed out.The characteristics of combined wideGangle low altitude light camera with selfGcalibration and selfGstabilization developed by the author are described,especially the principle of selfGcalibration for the combination of static error and dynamic error.Based on the practice of large scale mapping,a technical procedure in aerial photography by taking with wideGangle camera and large overlap simultaneously for improving the accuracy of low altitude photogrammetry is proposed.The typical engineering produced data is used to verity the above theoretical analysis.%首先从理论上对低空航测精度与相机像场角的关系进行定量分析,得出低空航测应尽可能使用宽角相机的结论;接着指明了单镜头相机扩大像场角的局限和现有市场上的组合宽角相机因重量过大而不适用于低空轻荷载无人机的不足,阐述了笔者研制的具有自检校自稳定功能的组合宽角低空轻小型相机的特点,尤其是实现组合成像静态误差和动态误差自检校的技术原理;针对大比例尺测图的实践,提出通过宽角相机大重叠航空摄影提高低空航测精度的技术建议;最后用典型工程生产数据验证了上述理论分析的正确性。

  19. Diagnosing Eyewitness Accuracy

    OpenAIRE

    Russ, Andrew

    2015-01-01

    Eyewitnesses frequently mistake innocent people for the perpetrator of an observed crime. Such misidentifications have led to the wrongful convictions of many people. Despite this, no reliable method yet exists to determine eyewitness accuracy. This thesis explored two new experimental methods for this purpose. Chapter 2 investigated whether repetition priming can measure prior exposure to a target and compared this with observers’ explicit eyewitness accuracy. Across three experiments slower...

  20. The effect of increased consumer demand on fees for aesthetic surgery: an economic analysis.

    Science.gov (United States)

    Krieger, L M; Shaw, W W

    1999-12-01

    Economic theory dictates that changes in consumer demand have predictable effects on prices. Demographics represents an important component of demand for aesthetic surgery. Between the years of 1997 and 2010, the U.S. population is projected to increase by 12 percent. The population increase will be skewed such that those groups undergoing the most aesthetic surgery will see the largest increase. Accounting for the age-specific frequencies of aesthetic surgery and the population increase yields an estimate that the overall market for aesthetic surgery will increase by 19 percent. Barring unforeseen changes in general economic conditions or consumer tastes, demand should increase by an analogous amount. An economic demonstration shows the effects of increasing demand for aesthetic surgery on its fees. Between the years of 1992 and 1997, there was an increase in demand for breast augmentation as fears of associated autoimmune disorders subsided. Similarly, there was increased male acceptance of aesthetic surgery. The number of breast augmentations and procedures to treat male pattern baldness, plastic surgeons, and fees for the procedures were tracked. During the study period, the supply of surgeons and consumer demand increased for both of these procedures. Volume of breast augmentation increased by 275 percent, whereas real fees remained stable. Volume of treatment for male pattern baldness increased by 107 percent, and the fees increased by 29 percent. Ordinarily, an increase in supply leads to a decrease in prices. This did not occur during the study period. Economic analysis demonstrates that the increased supply of surgeons performing breast augmentation was offset by increased consumer demand for the procedure. For this reason, fees were not lowered. Similarly, increased demand for treatment of male pattern baldness more than offset the increased supply of surgeons performing it. The result was higher fees. Emphasis should be placed on using these economic

  1. ANALYSIS OF THE INCREASE OF CONSTRUCTION COSTS IN URBAN REGENERATION PROJECTS

    Directory of Open Access Journals (Sweden)

    Magdalena Apollo

    2015-11-01

    Full Text Available The subject of this paper is the analysis and evaluation of the reasons for construction costs increases in urban regeneration projects. The analysis considers major refurbishments of real estates’, as well as heavy repair and modernization of the road system. For the period mentioned, the costs from works and expenditure schedules were compared with the costs of additional works, which shows the percentage cost increase in relation to initial project budget assumptions of the case study. The analysis revealed that due to difficulties in assessing technical state of inhabited buildings, the investor and potential contractor should pay special attention to the character of issues presented in this paper, taking into account an increased risk of their occurrence.

  2. Diagnostic accuracy and utility of coronary CT angiography with consideration of unevaluable results: A systematic review and multivariate Bayesian random-effects meta-analysis with intention to diagnose

    Energy Technology Data Exchange (ETDEWEB)

    Menke, Jan [University Medical Center Goettingen, Institute for Diagnostic and Interventional Radiology, Goettingen (Germany); Kowalski, Joerg [Dr. Lauterbach-Klinik, Department of Cardiology, Bad Liebenstein (Germany)

    2016-02-15

    To meta-analyze diagnostic accuracy, test yield and utility of coronary computed tomography angiography (CCTA) in coronary artery disease (CAD) by an intention-to-diagnose approach with inclusion of unevaluable results. Four databases were searched from 1/2005 to 3/2013 for prospective studies that used 16-320-row or dual-source CTs and provided 3 x 2 patient-level data of CCTA (positive, negative, or unevaluable) versus catheter angiography (positive or negative) for diagnosing ≥50 % coronary stenoses. A Bayesian multivariate 3 x 2 random-effects meta-analysis considered unevaluable CCTAs. Thirty studies (3422 patients) were included. Compared to 16-40 row CT, test yield and accuracy of CCTA has significantly increased with ≥64-row CT (P < 0.05). In ≥64-row CT, about 2.5 % (95 %-CI, 0.9-4.8 %) of diseased patients and 7.5 % (4.5-11.2 %) of non-diseased patients had unevaluable CCTAs. A positive likelihood ratio of 8.9 (6.1-13.5) indicated moderate suitability for identifying CAD. A negative likelihood ratio of 0.022 (0.01-0.04) indicated excellent suitability for excluding CAD. Unevaluable CCTAs had an equivocal likelihood ratio of 0.42 (0.22-0.71). In the utility analysis, CCTA was useful at intermediate pre-test probabilities (16-70 %). CCTA is useful at intermediate CAD pre-test probabilities. Positive CCTAs require verification to confirm CAD, unevaluable CCTAs require alternative diagnostics, and negative CCTAs exclude obstructive CAD with high certainty. (orig.)

  3. The value of predicting restriction of fetal growth and compromise of its wellbeing: Systematic quantitative overviews (meta-analysis of test accuracy literature

    Directory of Open Access Journals (Sweden)

    Robson Stephen C

    2007-03-01

    Full Text Available Abstract Background Restriction of fetal growth and compromise of fetal wellbeing remain significant causes of perinatal death and childhood disability. At present, there is a lack of scientific consensus about the best strategies for predicting these conditions before birth. Therefore, there is uncertainty about the best management of pregnant women who might have a growth restricted baby. This is likely to be due to a dearth of clear collated information from individual research studies drawn from different sources on this subject. Methods/Design A series of systematic reviews and meta-analyses will be undertaken to determine, among pregnant women, the accuracy of various tests to predict and/or diagnose fetal growth restriction and compromise of fetal wellbeing. We will search Medline, Embase, Cochrane Library, MEDION, citation lists of review articles and eligible primary articles and will contact experts in the field. Independent reviewers will select studies, extract data and assess study quality according to established criteria. Language restrictions will not be applied. Data synthesis will involve meta-analysis (where appropriate, exploration of heterogeneity and publication bias. Discussion The project will collate and synthesise the available evidence regarding the value of the tests for predicting restriction of fetal growth and compromise of fetal wellbeing. The systematic overviews will assess the quality of the available evidence, estimate the magnitude of potential benefits, identify those tests with good predictive value and help formulate practice recommendations.

  4. Thermodynamics of protein-ligand interactions as a reference for computational analysis: how to assess accuracy, reliability and relevance of experimental data.

    Science.gov (United States)

    Krimmer, Stefan G; Klebe, Gerhard

    2015-09-01

    For a conscientious interpretation of thermodynamic parameters (Gibbs free energy, enthalpy and entropy) obtained by isothermal titration calorimetry (ITC), it is necessary to first evaluate the experimental setup and conditions at which the data were measured. The data quality must be assessed and the precision and accuracy of the measured parameters must be estimated. This information provides the basis at which level discussion of the data is appropriate, and allows insight into the significance of comparisons with other data. The aim of this article is to provide the reader with basic understanding of the ITC technique and the experimental practices commonly applied, in order to foster an appreciation for how much measured thermodynamic parameters can deviate from ideal, error-free values. Particular attention is paid to the shape of the recorded isotherm (c-value), the influence of the applied buffer used for the reaction (protonation reactions, pH), the chosen experimental settings (temperature), impurities of protein and ligand, sources of systematic errors (solution concentration, solution activity, and device calibration) and to the applied analysis software. Furthermore, we comment on enthalpy-entropy compensation, heat capacities and van't Hoff enthalpies.

  5. VLT/SPHERE robust astrometry of the HR8799 planets at milliarcsecond-level accuracy Orbital architecture analysis with PyAstrOFit

    CERN Document Server

    Wertz, Olivier; González, Carlos A Gómez; Milli, Julien; Girard, Julen H; Mawet, Dimitri; Pueyo, Laurent

    2016-01-01

    HR8799 is orbited by at least four giant planets, making it a prime target for the recently commissioned Spectro-Polarimetric High-contrast Exoplanet REsearch (VLT/SPHERE). As such, it was observed on five consecutive nights during the SPHERE science verification in December 2014. We aim to take full advantage of the SPHERE capabilities to derive accurate astrometric measurements based on H-band images acquired with the Infra-Red Dual-band Imaging and Spectroscopy (IRDIS) subsystem, and to explore the ultimate astrometric performance of SPHERE in this observing mode. We also aim to present a detailed analysis of the orbital parameters for the four planets. We report the astrometric positions for epoch 2014.93 with an accuracy down to 2.0 mas, mainly limited by the astrometric calibration of IRDIS. For each planet, we derive the posterior probability density functions for the six Keplerian elements and identify sets of highly probable orbits. For planet d, there is clear evidence for nonzero eccentricity ($e \\...

  6. The diagnostic accuracy of CT and MRI in the staging of pelvic lymph nodes in patients with prostate cancer: a meta-analysis

    International Nuclear Information System (INIS)

    Aim: To compare the diagnostic accuracy of computed tomography (CT) and magnetic resonance imaging (MRI) in the diagnosis of lymph node metastases in prostate cancer. Methods: After a comprehensive literature search, studies were included that allowed construction of contingency tables for detection of lymph node metastases using CT or MRI. In addition, a summary receiver-operating characteristic (ROC) analysis was performed. Results: A total of 24 studies were included. For CT, pooled sensitivity was 0.42 (0.26-0.56 95% CI) and pooled specificity was 0.82 (0.8-0.83 95% CI). For MRI, the pooled sensitivity was 0.39 (0.22-0.56 95% CI) and pooled specificity was 0.82 (0.79-0.83 95% CI). The differences in performance of CT and MRI were not statistically significant. Conclusion: CT and MRI demonstrate an equally poor performance in the detection of lymph node metastases from prostate cancer. Reliance on either CT or MRI will misrepresent the patient's true status regarding nodal metastases, and thus misdirect the therapeutic strategies offered to the patient

  7. Diagnostic accuracy of PLA2R autoantibodies and glomerular staining for the differentiation of idiopathic and secondary membranous nephropathy: an updated meta-analysis.

    Science.gov (United States)

    Dai, Huanzi; Zhang, Huhai; He, Yani

    2015-01-01

    The diagnostic performance of M-type phospholipase A2 receptor (PLA2R) autoantibodies and PLA2R glomerular staining in discriminating between idiopathic membranous nephropathy (iMN) and secondary membranous nephropathy (sMN) has not been fully evaluated. We conducted an updated meta-analysis to investigate the accuracy and clinical value of serological anti-PLA2R test and histological PLA2R staining for differentiation iMN from sMN. A total of 19 studies involving 1160 patients were included in this meta-analysis. The overall sensitivity, specificity, diagnostic odds ratio (DOR) and area under the receiver operating characteristic curve (AUROC) of serum anti-PLA2R were 0.68 (95% CI, 0.61-074), 0.97 (95% CI, 0.85-1.00), 73.75 (95% CI, 12.56-432.96) and 0.82 (95% CI, 0.78-0.85), respectively, with substantial heterogeneity (I(2) = 86.42%). Subgroup analyses revealed the study design, publication type, study origin, assay method might account for the heterogeneity. Additionally, the overall sensitivity, specificity, DOR and AUROC of glomerular PLA2R staining were 0.78 (95% CI, 0.72-0.83), 0.91 (95% CI, 0.75-0.97), 34.70 (95% CI, 9.93-121.30) and 0.84 (95% CI, 0.81-0.87), respectively, without heterogeneity (I(2) = 0%). Serological anti-PLA2R testing has diagnostic value, but it must be interpreted in context with patient clinical characteristics and histological PLA2R staining in seronegative patients is recommended.

  8. The diagnostic accuracy of magnetic resonance venography in the detection of deep venous thrombosis: a systematic review and meta-analysis

    International Nuclear Information System (INIS)

    Aim: To search the literature for further evidence for the use of magnetic resonance venography (MRV) in the detection of suspected DVT and to re-evaluate the accuracy of MRV in the detection of suspected deep vein thrombosis (DVT). Materials and methods: PubMed, EMBASE, Scopus, Cochrane, and Web of Science were searched. Study quality and the risk of bias were evaluated using the QUADAS 2. A random effects meta-analysis including subgroup and sensitivity analyses were performed. Results: The search resulted in 23 observational studies all from academic centres. Sixteen articles were included in the meta-analysis. The summary estimates for MRV as a diagnostic non-invasive tool revealed a sensitivity of 93% (95% confidence interval [CI]: 89% to 95%) and specificity of 96% (95% CI: 94% to 97%). The heterogeneity of the studies was high. Inconsistency (I2) for sensitivity and specificity was 80.7% and 77.9%, respectively. Conclusion: Further studies investigating the use of MRV in the detection of suspected DVT did not offer further evidence to support the replacement of ultrasound with MRV as the first-line investigation. However, MRV may offer an alternative tool in the detection/diagnosis of DVT for whom ultrasound is inadequate or not feasible (such as in the obese patient). -- Highlights: •We aimed to search the literature for evidence for the use of MRV in the detection of suspected DVT. •We questioned the use of MRV in special populations like the obese where contrast venography may not be feasible or safe. •MRV may not replace ultrasound as the first-line modality for DVT detection. •Consider MRV use in special populations like the obese where other diagnostic tools are not feasible. •Studies to compare MRV vs. ultrasound as a screening tool for DVT in the obese should be considered

  9. How far can the radiation dose be lowered in head CT with iterative reconstruction? Analysis of imaging quality and diagnostic accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Tung-Hsin; Sun, Jing-Yi [National Yang-Ming University, Department of Biomedical Imaging and Radiological Sciences, Taipei (China); Hung, Sheng-Che; Lin, Chung-Jung; Chiu, Chen Fen; Liu, Min-Jsuan; Teng, Michael Mu Huo; Guo, Wan-Yuo; Chang, Cheng-Yen [Taipei Veterans General Hospital, Department of Radiology, Taipei (China); National Yang-Ming University, School of Medicine, Taipei (China); Lin, Chung-Hsien [National Taiwan University, Graduate Institute of Epidemiology and Preventive Medicine, Taipei (China)

    2013-09-15

    To evaluate the imaging quality of head CT at lowered radiation dose by combining filtered back projection (FBP) and iterative reconstruction (IR) algorithms. Experimental group A (n = 66) underwent CT with 43 % tube current reduction, and group B (n = 58) received an equivalent reduced dose by lowering the tube voltage. An age- and sex-matched control group (n = 72) receiving the conventional radiation dose was retrospectively collected. Imaging for the control group was reconstructed by FBP only, while images for groups A and B were reconstructed by FBP and IR. The signal-to-noise ratios (SNRs), contrast-to-noise ratios (CNRs), sharpness, number of infarcts and severity of subcortical arteriosclerotic encephalopathy (SAE) were compared to assess imaging quality and diagnostic accuracy. There were no significant differences in SNRs and CNRs between group A and the control group. There were significantly decreased SNRs and increased CNRs in group B. Image sharpness decreased in both groups. Correlations between detected infarcts and severity of SAE across FBP and IR were high (r = 0.73-0.93). Head diameter was the only significant factor inversely correlated with infratentorial imaging quality. Head CT with 43 % reduced tube current reconstructed by IR provides diagnostic imaging quality for outpatient management. (orig.)

  10. 星点亚像元细分定位精度分析%Accuracy Analysis for Sub-Pixel Location of Star Image

    Institute of Scientific and Technical Information of China (English)

    连月勇; 张超; 谢宗特

    2015-01-01

    Precise positioning of the star could provide key data for subsequent navigation calculation. Various star point’ s numerical simulations were characterized to vertify the positioning method, according to the principle of Gauss distribution. Centroid algorithm and Gaussian surface fitness algorithm were introduced in this paper, the effect factors on star position accuracy were studied, which include the gray system error, random noise, segmenta-tion threshold, magnitude and coordinate distribution. The similarities and differences of the two star position loca-ting method were indepth analysed. According to the study of simulation experiment, distance between star and ref-erence point is farther, positioning error is larger, and the positioning error rises with random noise increasing. The experimental results show that, compared to the Gauss surface fitness method, centroid method has better practica-bility and its positioning accuracy has less dependence on pixel information of star point.%星点的精确定位为后续的导航解算提供数据支撑。基于高斯分布原理进行星点模拟,为星点定位提供图像数据。分别介绍了质心法和高斯曲面拟合法的亚像元细分定位原理,并研究系统误差、随机噪声、分割阈值、星等和星点坐标分布5个因素对星点定位精度的影响,分析两种方法的异同点。对模拟的星点进行定位分析发现,星点距离参考点越远定位误差越大,定位精度随噪声增大而降低。实验表明,相比高斯曲面拟合方法,质心法具有更好的实用性,其定位精度对星点的像元信息依赖性较小。

  11. Analysis of power and frequency control requirements in view of increased decentralized production and market liberalization

    NARCIS (Netherlands)

    Roffel, Brian; Boer, de Wouter W.

    2003-01-01

    This paper presents a systematic approach of the analysis of the minimum control requirements that are imposed on power producing units in the Netherlands, especially in the case when decentralized production increases. Also some effects of the liberalization on the control behavior are analyzed. Fi

  12. Interventions to Increase Attendance at Psychotherapy: A Meta-Analysis of Randomized Controlled Trials

    Science.gov (United States)

    Oldham, Mary; Kellett, Stephen; Miles, Eleanor; Sheeran, Paschal

    2012-01-01

    Objective: Rates of nonattendance for psychotherapy hinder the effective delivery of evidence-based treatments. Although many strategies have been developed to increase attendance, the effectiveness of these strategies has not been quantified. Our aim in the present study was to undertake a meta-analysis of rigorously controlled studies to…

  13. A Systematic Review and Meta-Analysis of Indicated Interventions to Increase School Attendance

    Science.gov (United States)

    Maynard, Brandy R.; Tyson-McCrea, Katherine; Pigott, Therese; Kelly, Michael

    2011-01-01

    The main objective of this systematic review and meta-analysis was to examine the effects of intervention programs on school attendance behaviors of elementary and secondary school students to inform policy and practice. The specific questions guiding this study were: (1) Do indicated programs with a goal of increasing student attendance affect…

  14. Evaluating Measurement Accuracy

    CERN Document Server

    Rabinovich, Semyon G

    2010-01-01

    The goal of Evaluating Measurement Accuracy: A Practical Approach is to present methods for estimating the accuracy of measurements performed in industry, trade, and scientific research. Although multiple measurements are the focus of current theory, single measurements are the ones most commonly used. This book answers fundamental questions not addressed by present theory, such as how to discover the complete uncertainty of a measurement result. In developing a general theory of processing experimental data, this book, for the first time, presents the postulates of the theory of measurements. It introduces several new terms and definitions about the relationship between the accuracy of measuring instruments and measurements utilizing these instruments. It also offers well-grounded and practical methods for combining the components of measurement inaccuracy. From developing the theory of indirect measurements to proposing new methods of reduction in place of the traditional ones, this work encompasses the ful...

  15. Diagnostic accuracy and impact on management of {sup 18}F-FDG PET and PET/CT in colorectal liver metastasis: a meta-analysis and systematic review

    Energy Technology Data Exchange (ETDEWEB)

    Maffione, Anna Margherita; Rubello, Domenico [S.M. della Misericordia Hospital, PET Unit, Nuclear Medicine Department, Rovigo (Italy); Lopci, Egesta [Humanitas Research Hospital, Department of Nuclear Medicine, Milano (Italy); Bluemel, Christina; Herrmann, Ken [University Hospital Wuerzburg, Department of Nuclear Medicine, Wuerzburg (Germany); Giammarile, Francesco [Centre Hospitalier Lyon Sud Biophysique, Department of Nuclear Medicine, Lyon (France)

    2015-01-15

    The first aim of the review (aim 1) was to obtain the diagnostic performance values of {sup 18}F-FDG PET for the detection and staging of liver metastases in patients with colorectal cancer (CRC), the second aim (aim 2) was to compare PET and conventional imaging modalities, and the third aim (aim 3) was to evaluate the impact of PET on patient management. The incidence of extrahepatic disease (EHD) detected by PET is also reviewed. A comprehensive search was performed on PubMed/MEDLINE for studies evaluating PET and PET/CT in CRC patients with liver metastases up to June 2014. For inclusion PET had to have been performed prior to surgery, there had to be at least 18 patients in the study, and the reported data had to allow calculation of 2 x 2 contingency tables (for aim 1). A total of 18 studies were eligible for at least one of the three intended subanalyses including a total of 1,059 patients. Pooled sensitivity, specificity and accuracy and the corresponding 95 % confidence intervals were derived from the contingency tables on a patient basis (patient-based analysis, PBA) and a lesion basis (lesion-based analysis, LBA) for eight studies. Pooled sensitivity and specificity of PET on PBA were both 93 %. Corresponding values for LBA were 60 % and 79 %, respectively. Areas under the summary ROC were 0.97 for PBA and 0.67 for LBA. Regarding aim 2, PET had a slightly lower sensitivity than MRI and CT on PBA (93 %, 100 % and 98 %, respectively) and LBA (66 %, 89 % and 79 %, respectively) but appeared to be more specific than MRI and CT (86 %, 81 % and 67 %, respectively). PET findings resulted in changes in the management of a mean of 24 % of patients. The mean incidence of PET-based EHD was 32 %. This meta-analysis suggests that FDG PET/CT is highly accurate for the detection of liver metastases on a patient basis but less accurate on a lesion basis. Compared to MRI, PET is less sensitive but more specific and affects the management of about one-quarter of patients

  16. Diagnostic accuracy and impact on management of 18F-FDG PET and PET/CT in colorectal liver metastasis: a meta-analysis and systematic review

    International Nuclear Information System (INIS)

    The first aim of the review (aim 1) was to obtain the diagnostic performance values of 18F-FDG PET for the detection and staging of liver metastases in patients with colorectal cancer (CRC), the second aim (aim 2) was to compare PET and conventional imaging modalities, and the third aim (aim 3) was to evaluate the impact of PET on patient management. The incidence of extrahepatic disease (EHD) detected by PET is also reviewed. A comprehensive search was performed on PubMed/MEDLINE for studies evaluating PET and PET/CT in CRC patients with liver metastases up to June 2014. For inclusion PET had to have been performed prior to surgery, there had to be at least 18 patients in the study, and the reported data had to allow calculation of 2 x 2 contingency tables (for aim 1). A total of 18 studies were eligible for at least one of the three intended subanalyses including a total of 1,059 patients. Pooled sensitivity, specificity and accuracy and the corresponding 95 % confidence intervals were derived from the contingency tables on a patient basis (patient-based analysis, PBA) and a lesion basis (lesion-based analysis, LBA) for eight studies. Pooled sensitivity and specificity of PET on PBA were both 93 %. Corresponding values for LBA were 60 % and 79 %, respectively. Areas under the summary ROC were 0.97 for PBA and 0.67 for LBA. Regarding aim 2, PET had a slightly lower sensitivity than MRI and CT on PBA (93 %, 100 % and 98 %, respectively) and LBA (66 %, 89 % and 79 %, respectively) but appeared to be more specific than MRI and CT (86 %, 81 % and 67 %, respectively). PET findings resulted in changes in the management of a mean of 24 % of patients. The mean incidence of PET-based EHD was 32 %. This meta-analysis suggests that FDG PET/CT is highly accurate for the detection of liver metastases on a patient basis but less accurate on a lesion basis. Compared to MRI, PET is less sensitive but more specific and affects the management of about one-quarter of patients. (orig.)

  17. Increasing shape modelling accuracy by adjusting for subject positioning: An application to the analysis of radiographic proximal femur symmetry using data from the Osteoarthritis Initiative ☆

    OpenAIRE

    Lindner, C; Wallis, G A; Cootes, T.F.

    2014-01-01

    In total hip arthroplasty, the shape of the contra-lateral femur frequently serves as a template for preoperative planning. Previous research on contra-lateral femoral symmetry has been based on conventional hip geometric measurements (which reduce shape to a series of linear measurements) and did not take the effect of subject positioning on radiographic femur shape into account. The aim of this study was to analyse proximal femur symmetry based on statistical shape models (SSMs) which quant...

  18. The Truth about Accuracy

    NARCIS (Netherlands)

    Buekens, F.A.I.; Truyen, Frederick; Martini, Carlo; Boumans, Marcel

    2014-01-01

    When we evaluate the outcomes of investigative actions as justified or unjustified, good or bad, rational or irrational, we make, in a broad sense of the term, evaluative judgements about them. We look at operational accuracy as a desirable and evaluable quality of the outcomes and explore how the c

  19. Improvement in the accuracy of dual energy x-ray absorptiometry for whole body and regional analysis of body composition: validation using piglets and methodologic considerations in infants.

    Science.gov (United States)

    Brunton, J A; Weiler, H A; Atkinson, S A

    1997-04-01

    Previously, we conducted dual energy x-ray absorptiometry (DXA) (Hologic QDR-1000/W) scans and carcass analysis of piglets to evaluate the Pediatric Whole Body software (PedWB) (V5.35) for use in infants. A software upgrade designed for infant whole body (InfWB) (V5.56) led to a reassessment of DXA by: 1) reanalysis of the original scans using InfWB software and 2) comparison of InfWB-estimates of bone mineral content (BMC) and lean and fat mass with chemical analysis. Other assessments included 1) methods of regional analysis and 2) artifacts and the Infant Table Pad in the scan field. The mean coefficients of variation for InfWB whole body measures in small piglets (n = 10, weight 1575 +/- 73 g) and large piglets (n = 10, weight 5894 +/- 208 g) were less than 2.6% except for fat mass which was higher (8.0% versus 6.3% and 6.6% versus 3.5%, respectively) compared with PedWB. In large piglets InfWB produced good estimates of BMC, lean and fat masses. In small piglets, fat mass by InfWB was correlated with chemical analysis, but not by PedWB. There was improvement in the estimation of BMC with InfWB, from 27 +/- 2.2 g to 32 +/- 2.3 g (carcass ash = 38 +/- 3.3 g). Femur BMC analysis by InfWB was precise and was accurate when compared with chemical analysis. Artifacts in the DXA scan field (diapers and blankets) resulted in an increase of the DXA-estimated fat and lean masses. The Infant Table Pad increased the estimate of fat mass in a small piglet by 50%, thus further study is required before it is used routinely. Improvements of the DXA technology have resulted in a more accurate tool, if scanning procedures are carefully implemented. PMID:9098865

  20. An analysis of increasing the size of the strategic petroleum reserve to one billion barrels

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    The Department of Energy's Office of Energy Emergency Policy and Evaluation requested that the Energy Information Administration complete an analysis of the proposed expansion in the Strategic Petroleum Reserve (SPR) from its currently planned size of 750 million barrels to 1000 million barrels. Because the SPR contains only 580 million barrels at this point in time, the benefits and costs of increasing the SPR from 600 to 750 million barrels were also estimated. This report documents the assumptions, methodology, and results of the analysis. 17 figs., 15 tabs.

  1. Evaluation of the contribution of LiDAR data and postclassification procedures to object-based classification accuracy

    Science.gov (United States)

    Styers, Diane M.; Moskal, L. Monika; Richardson, Jeffrey J.; Halabisky, Meghan A.

    2014-01-01

    Object-based image analysis (OBIA) is becoming an increasingly common method for producing land use/land cover (LULC) classifications in urban areas. In order to produce the most accurate LULC map, LiDAR data and postclassification procedures are often employed, but their relative contributions to accuracy are unclear. We examined the contribution of LiDAR data and postclassification procedures to increase classification accuracies over using imagery alone and assessed sources of error along an ecologically complex urban-to-rural gradient in Olympia, Washington. Overall classification accuracy and user's and producer's accuracies for individual classes were evaluated. The addition of LiDAR data to the OBIA classification resulted in an 8.34% increase in overall accuracy, while manual postclassification to the imagery+LiDAR classification improved accuracy only an additional 1%. Sources of error in this classification were largely due to edge effects, from which multiple different types of errors result.

  2. Development of integrated transport analysis suite for LHD plasmas towards transport model validation and increased predictability

    International Nuclear Information System (INIS)

    In this study, the integrated transport analysis suite, TASK3D-a, was developed to enhance the physics understanding and accurate discussion of the Large Helical Device (LHD) experiment toward facilitating transport model validation. Steady-state and dynamic (transient) transport analyses of NBI (neutral-beam-injection)-heated LHD plasmas have been greatly facilitated by this suite. This will increase the predictability of the transport properties of LHD plasmas toward reactor-relevant regimes and reactor-scale plasmas. (author)

  3. Does ovarian stimulation for IVF increase gynaecological cancer risk? A systematic review and meta-analysis.

    Science.gov (United States)

    Zhao, Jing; Li, Yanping; Zhang, Qiong; Wang, Yonggang

    2015-07-01

    The aim of this study was to evaluate whether ovarian stimulation for IVF increases the risk of gynaecological cancer, including ovarian, endometrial, cervical and breast cancers, as an independent risk factor. A systematic review and meta-analysis was conducted. Clinical trials that examined the association between ovarian stimulation for IVF and gynaecologic cancers were included. The outcomes of interest were incidence rate of gynaecologic cancers. Twelve cohort studies with 178,396 women exposed to IVF were included; 10 studies were used to analyse ovarian (167,640 women) and breast (151,702 women) cancers, and six studies were identified in the analysis of endometrial (116,672 women) and cervical cancer (114,799 women). Among these studies, 175 ovarian, 48 endometrial, 502 cervical and 866 cases of breast cancer were reported. The meta-analysis found no significant association between ovarian stimulation for IVF and increased ovarian, endometrial, cervical and breast cancer risk (odds ratio [OR] 1.06, 95% confidence interval [CI] 0.85 to 1.32; OR 0.97, 95% CI 0.58 to 1.63; OR 0.43, 95% CI 0.30 to 0.60; OR 0.69, 95% CI 0.63 to 0.76, respectively). Ovarian stimulation for IVF, therefore, does not increase the gynaecologic cancer risk, whether hormone-dependent endometrial and breast cancer or non-hormone-dependent ovarian and cervical cancer. PMID:26003452

  4. Metabolic Syndrome Increases the Risk for Knee Osteoarthritis: A Meta-Analysis

    Science.gov (United States)

    Wang, Huajun; Cheng, Yanmei; Shao, Decheng; Chen, Junyuan; Sang, Yuan; Gui, Tao; Luo, Simin; Li, Jieruo; Chen, Chao; Ye, Yongguang; Yang, Yong; Li, Yikai

    2016-01-01

    Background. Studies revealed that metabolic factors might contribute substantially to osteoarthritis (OA) pathogenesis. There has been an increasing interest to understand the relationship between knee OA and the metabolic syndrome (MetS). The purpose of this study was to explore the association between metabolic syndrome and knee osteoarthritis using meta-analysis. Methods. Databases, including PUBMED, EMBASE, and the Cochrane Library, were searched to get relevant studies. Data were extracted separately by two authors and pooled odds ratio (OR) with 95% confidence interval (CI) was calculated. Results. The meta-analysis was finished with 8 studies with a total of 3202 cases and 20968 controls finally retrieved from the database search. The crude pooled OR is 2.24 (95% CI = 1.38–3.64). Although there was significant heterogeneity among these studies, which was largely accounted for by a single study, the increase in risk was still significant after exclusion of that study. The pooled adjusted OR remained significant with pooled adjusted OR 1.05 (95% CI = 1.03–1.07, p < 0.00001). No publication bias was found in the present meta-analysis. Conclusions. The synthesis of available evidence supports that metabolic syndrome increases the risk for knee osteoarthritis, even after adjustment for many risk factors.

  5. Data mining methods in the prediction of Dementia: A real-data comparison of the accuracy, sensitivity and specificity of linear discriminant analysis, logistic regression, neural networks, support vector machines, classification trees and random forests

    Directory of Open Access Journals (Sweden)

    Santana Isabel

    2011-08-01

    Full Text Available Abstract Background Dementia and cognitive impairment associated with aging are a major medical and social concern. Neuropsychological testing is a key element in the diagnostic procedures of Mild Cognitive Impairment (MCI, but has presently a limited value in the prediction of progression to dementia. We advance the hypothesis that newer statistical classification methods derived from data mining and machine learning methods like Neural Networks, Support Vector Machines and Random Forests can improve accuracy, sensitivity and specificity of predictions obtained from neuropsychological testing. Seven non parametric classifiers derived from data mining methods (Multilayer Perceptrons Neural Networks, Radial Basis Function Neural Networks, Support Vector Machines, CART, CHAID and QUEST Classification Trees and Random Forests were compared to three traditional classifiers (Linear Discriminant Analysis, Quadratic Discriminant Analysis and Logistic Regression in terms of overall classification accuracy, specificity, sensitivity, Area under the ROC curve and Press'Q. Model predictors were 10 neuropsychological tests currently used in the diagnosis of dementia. Statistical distributions of classification parameters obtained from a 5-fold cross-validation were compared using the Friedman's nonparametric test. Results Press' Q test showed that all classifiers performed better than chance alone (p Conclusions When taking into account sensitivity, specificity and overall classification accuracy Random Forests and Linear Discriminant analysis rank first among all the classifiers tested in prediction of dementia using several neuropsychological tests. These methods may be used to improve accuracy, sensitivity and specificity of Dementia predictions from neuropsychological testing.

  6. The Accuracy of Multiples

    Directory of Open Access Journals (Sweden)

    Stauropoulos Antonios

    2011-01-01

    Full Text Available Problem statement: Equity valuation with the use of multiples is widely used by academics and practitioners concerning its functionality. This study aims to explore the sensitivity of three multiples in terms of accuracy. Approach: Price-to-Sales (P/S multiple, the price-to-book value of equity (P/B multiple and the Price-to-Earnings (P/E multiple are three multiples under consideration, using both current and one-year-ahead earnings forecasts. Results: Evidence of empirical results show that, the multiples P/mdfy1 and P/mnfy1 are effective in terms of accuracy, with their means being negatively biased and their medians being positively biased. Finally, current earnings are identified as more appropriate value driver for the calculation of the P/E ratio by terms of accuracy. The results can be considered as reliable owing to the large sample and the procedure followed for its selection. Conclusion: This study offers a better understanding of the valuation approach through the use of multiples, in order analysts assumption to be more carefully and properly chosen and their results to be more accurately produced.

  7. The Application Value of High Resolution CT Scan in Increase the Diagnosis of Bronchiectasis Sensitivity and Accuracy%高分辨率CT扫描在提高诊断支气管扩张敏感性、准确性的应用价值

    Institute of Scientific and Technical Information of China (English)

    田志强; 严天军

    2016-01-01

    Objective To discuss the application value of high resolution CT scan in increase the diagnosis of bronchiectasis sensitivity, accuracy.Methods 60 patients with bronchiectasis were selected from January 2010 to June 2014 in our Hospitals, according to the random distribution, all patients were divided into CT group and high CT group, based on the expansion of CT pulmonary segments performance,all patients were divided into cylindrical type, cystic type, mixed type and varicose, CT group was given conventional CT scanning, high CT group was given high resolution CT scan, analysed all patients' CT manifestation,and used ROC curve analysis to analysis two kinds of CT scanning of value in the differential diagnosis of bronchiectasis.Results High CT group Bronchiectasis detection rate was obviously higher than CT group, the difference was statistically significant (P<0.05), High CT group to identify high columnar type, cystic type, mixed type and varicose bronchiectasis accuracy rate was significantly higher than CT group(P<0.05), ROC curve results showed that, CT scan differential diagnosis of bronchiectasis sensitivity of 81.26%, specificity of 78.69%, the accuracy of 84.56%, high resolution CT scan differential diagnosis of bronchiectasis sensitivity of 89.12%, specificity of 86.24%, the accuracy of 95.28%.Conclusions High resolution CT scan can effectively improve the accuracy in the detection rate and the identification of bronchiectasis disease type, in the differential diagnosis of bronchiectasis with higher sensitivity and accuracy, it's worth for further clinical promotion.%目的:探讨高分辨率CT扫描在提高诊断支气管扩张敏感性、准确性的应用价值。方法选取2010年1月至2014年6月期间我院临床和手术病理证实的支气管扩张患者60例,依据随机分配原则分为CT组和高分辨率CT组,依据肺段支扩表现分为柱状型、囊状型、混合型和曲张型,CT组给予常规CT扫描检测,高分辨

  8. 高分辨率CT扫描在提高诊断支气管扩张敏感性、准确性的应用价值%The Application Value of High Resolution CT Scan in Increase the Diagnosis of Bronchiectasis Sensitivity, Accuracy

    Institute of Scientific and Technical Information of China (English)

    肖飞鹰

    2015-01-01

    Objective To discuss the application value of high resolution CT scan in increase the diagnosis of bronchiectasis sensitivity, accuracy.Methods 60 patients with bronchiectasis were selected from January 2010 to June 2014 in our Hospitals, according to the random distribution, all patients were divided into CT group and high CT group, based on the expansion of CT pulmonary segments performance,all patients were divided into cylindrical type, cystic type, mixed type and varicose, CT group was given conventional CT scanning, high CT group was given high resolution CT scan, analysed all patients’ CT manifestation,and used ROC curve analysis to analysis two kinds of CT scanning of value in the differential diagnosis of bronchiectasis.Results High CT group Bronchiectasis detection rate was obviously higher than CT group, the difference was statistically signiifcant (P<0.05); High CT group to identify high columnar type, cystic type, mixed type and varicose bronchiectasis accuracy rate was signiifcantly higher than CT group(P < 0.05); ROC curve results showed that, CT scan differential diagnosis of bronchiectasis sensitivity of 81.26%, speciifcity of 78.69%, the accuracy of 84.56%, high resolution CT scan differential diagnosis of bronchiectasis sensitivity of 89.12%, speciifcity of 86.24%, the accuracy of 95.28%.Conclusions High resolution CT scan can effectively improve the accuracy in the detection rate and the identiifcation of bronchiectasis disease type, in the differential diagnosis of bronchiectasis with higher sensitivity and accuracy,it’s worth for further clinical promotion.%目的:探讨高分辨率CT扫描在提高诊断支气管扩张敏感性、准确性的应用价值。方法选取2010年1月至2014年6月期间我院临床和手术病理证实的支气管扩张患者60例,依据随机分配原则分为CT组和高CT组,依据肺段支扩表现分为柱状型、囊状型、混合型和曲张型,CT组给予常规CT扫描检测,高CT组给予

  9. Change Detection Accuracy and Image Properties: A Study Using Simulated Data

    Directory of Open Access Journals (Sweden)

    Abdullah Almutairi

    2010-06-01

    Full Text Available Simulated data were used to investigate the relationships between image properties and change detection accuracy in a systematic manner. The image properties examined were class separability, radiometric normalization and image spectral band-to-band correlation. The change detection methods evaluated were post-classification comparison, direct classification of multidate imagery, image differencing, principal component analysis, and change vector analysis. The simulated data experiments showed that the relative accuracy of the change detection methods varied with changes in image properties, thus confirming the hypothesis that caution should be used in generalizing from studies that use only a single image pair. In most cases, direct classification and post-classification comparison were the least sensitive to changes in the image properties of class separability, radiometric normalization error and band correlation. Furthermore, these methods generally produced the highest accuracy, or were amongst those with a high accuracy. PCA accuracy was highly variable; the use of four principal components consistently resulted in substantial decreased classification accuracy relative to using six components, or classification using the original six bands. The accuracy of image differencing also varied greatly in the experiments. Of the three methods that require radiometric normalization, image differencing was the method most affected by radiometric error, relative to change vector and classification methods, for classes that have moderate and low separability. For classes that are highly separable, image differencing was relatively unaffected by radiometric normalization error. CVA was found to be the most accurate method for classes with low separability and all but the largest radiometric errors. CVA accuracy tended to be the least affected by changes in the degree of band correlation in situations where the class means were moderately dispersed, or

  10. The accuracy of ultrasonography in the preoperative diagnosis of cervical lymph node metastasis in patients with papillary thyroid carcinoma: A meta-analysis

    International Nuclear Information System (INIS)

    Background: Ultrasonography has been proposed to enhance preoperative assessment of cervical lymph node status in patients with papillary thyroid carcinoma (PTC). Management is most controversial for patients with a clinically negative (cN0) neck. We aimed to evaluate the diagnostic properties of ultrasonography in the detection of cervical lymph node metastasis in patients with PTC. Materials and methods: Studies evaluating the diagnostic accuracy of Ultrasonography in the diagnosis of cervical lymph node metastasis in patients with PTC were systematically searched for in the MEDLINE, EMBASE, Cancerlit and Cochrane Library and other database from January 1995 to November 2010. Two reviewers independently abstracted data including research design, sample size, imaging technique and technical characteristics, method of image interpretation. By patient-based and region- or node-based data analyses, we determined pooled sensitivities and specificities across studies, and constructed summary receiver operating characteristic curves, and area under summary receiver operating characteristic curves were calculated. Results: The pooled patient-based sensitivity for ultrasonography was 0.72 (95% CI, 0.46–0.88), specificity was 0.98 (95% CI, 0.84–1.00), and the area under the curve (AUC) was 0.94 (95% CI, 0.92–0.0.96). The pooled region- or node-based sensitivity for ultrasonography was 0.63 (95% CI, 0.47–0.76), specificity was 0.93 (95% CI, 0.73–0.99), and the AUC was 0.81 (95% CI, 0.77–0.84). For lesion-based analysis, the subgroup of lateral compartment lymph node involvement was found to have the highest sensitivity (0.72, 95% CI 0.68–0.75) and specificity (0.97, 95% CI 0.93–0.99) among the studies (p 2 = 0.0196, p = 0.7915; region- or node-based: R2 = 0.3835, p = 0.1381). Conclusions: We conclude that preoperative ultrasonography is a good technique for the preoperative lymph node staging of PTC and is helpful for detecting metastatic cervical lymph

  11. The accuracy of ultrasonography in the preoperative diagnosis of cervical lymph node metastasis in patients with papillary thyroid carcinoma: A meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Lian-Ming; Gu, Hai-Yan [Department of Radiology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127 (China); Qu, Xin-Hua [Department of Orthopaedics, Ninth People' s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127 (China); Zheng, Jasmine [Georgetown University School of Medicine, Washington, DC, 20057 (United States); Zhang, Wei; Yin, Yan [Department of Radiology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127 (China); Xu, Jian-Rong, E-mail: xujianr@yeah.net [Department of Radiology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127 (China)

    2012-08-15

    Background: Ultrasonography has been proposed to enhance preoperative assessment of cervical lymph node status in patients with papillary thyroid carcinoma (PTC). Management is most controversial for patients with a clinically negative (cN0) neck. We aimed to evaluate the diagnostic properties of ultrasonography in the detection of cervical lymph node metastasis in patients with PTC. Materials and methods: Studies evaluating the diagnostic accuracy of Ultrasonography in the diagnosis of cervical lymph node metastasis in patients with PTC were systematically searched for in the MEDLINE, EMBASE, Cancerlit and Cochrane Library and other database from January 1995 to November 2010. Two reviewers independently abstracted data including research design, sample size, imaging technique and technical characteristics, method of image interpretation. By patient-based and region- or node-based data analyses, we determined pooled sensitivities and specificities across studies, and constructed summary receiver operating characteristic curves, and area under summary receiver operating characteristic curves were calculated. Results: The pooled patient-based sensitivity for ultrasonography was 0.72 (95% CI, 0.46-0.88), specificity was 0.98 (95% CI, 0.84-1.00), and the area under the curve (AUC) was 0.94 (95% CI, 0.92-0.0.96). The pooled region- or node-based sensitivity for ultrasonography was 0.63 (95% CI, 0.47-0.76), specificity was 0.93 (95% CI, 0.73-0.99), and the AUC was 0.81 (95% CI, 0.77-0.84). For lesion-based analysis, the subgroup of lateral compartment lymph node involvement was found to have the highest sensitivity (0.72, 95% CI 0.68-0.75) and specificity (0.97, 95% CI 0.93-0.99) among the studies (p < 0.05). Study sensitivity was not correlated with the prevalence of cervical lymph node metastasis (patient-based: R{sup 2} = 0.0196, p = 0.7915; region- or node-based: R{sup 2} = 0.3835, p = 0.1381). Conclusions: We conclude that preoperative ultrasonography is a good

  12. Development of C-reactive protein certified reference material NMIJ CRM 6201-b: optimization of a hydrolysis process to improve the accuracy of amino acid analysis.

    Science.gov (United States)

    Kato, Megumi; Kinumi, Tomoya; Yoshioka, Mariko; Goto, Mari; Fujii, Shin-Ichiro; Takatsu, Akiko

    2015-04-01

    To standardize C-reactive protein (CRP) assays, the National Metrology Institute of Japan (NMIJ) has developed a C-reactive protein solution certified reference material, CRM 6201-b, which is intended for use as a primary reference material to enable the SI-traceable measurement of CRP. This study describes the development process of CRM 6201-b. As a candidate material of the CRM, recombinant human CRP solution was selected because of its higher purity and homogeneity than the purified material from human serum. Gel filtration chromatography was used to examine the homogeneity and stability of the present CRM. The total protein concentration of CRP in the present CRM was determined by amino acid analysis coupled to isotope-dilution mass spectrometry (IDMS-AAA). To improve the accuracy of IDMS-AAA, we optimized the hydrolysis process by examining the effect of parameters such as the volume of protein samples taken for hydrolysis, the procedure of sample preparation prior to the hydrolysis, hydrolysis temperature, and hydrolysis time. Under optimized conditions, we conducted two independent approaches in which the following independent hydrolysis and liquid chromatography-isotope dilution mass spectrometry (LC-IDMS) were combined: one was vapor-phase acid hydrolysis (130 °C, 24 h) and hydrophilic interaction liquid chromatography-mass spectrometry (HILIC-MS) method, and the other was microwave-assisted liquid-phase acid hydrolysis (150 °C, 3 h) and pre-column derivatization liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. The quantitative values of the two different amino acid analyses were in agreement within their uncertainties. The certified value was the weighted mean of the results of the two methods. Uncertainties from the value-assignment method, between-method variance, homogeneity, long-term stability, and short-term stability were taken into account in evaluating the uncertainty for a certified value. The certified value and the

  13. Literal analysis of potential interference from satellites with the proposed pfd increase

    Energy Technology Data Exchange (ETDEWEB)

    Jeske, H.O.

    1986-01-01

    An increase in the maximum power flux-density (pfd) permitted from satelltes in the 2025 to 2300 MHz band is currently under consideration by IRAC. This analysis assumes the worst case conditions for interference to telemetry operations at the missile test ranges as a result of current and proposed satellite pfd levels. Assumptions in the analysis include the maximum permitted power flux-density with uniform energy distribution over the band of interest, polarization compatibility, and alignment of the telemetry station, the missile and the satellite. It was found that the performance of essentially all missile telemetry receiving systems may be appreciably degraded by even the lowest pfd limits currently permitted. For the higher pfd limits under consideration, degradations in the order of 40 dB are to be expected at stations with dish antennas of only five foot diameter. An increase in the size or gain of an antenna will reduce the probability of interference, because of its decreased beamwidth, but will also increase the performance degradation because of the station's increased figure of merit, G/T. For satisfactory missile telemetry operation under these conditions, the normal missile's telemetry received signal-to-noise ratio would have to be well over 40 dB to overcome satellite interference. The results of the analysis are actually independent of all receiving station parameters except the station's figure of merit, G/T. Probability of interference is not addressed because of the variation of conditions and missions of the various test ranges as well as the unknown number of satellites and their characteristics - present and future.

  14. Analysis of primary risk factors for oral cancer from select US states with increasing rates

    Directory of Open Access Journals (Sweden)

    O'Malley Susan

    2010-02-01

    Full Text Available Abstract Objectives To examine the primary risk factor for oral cancer in the US, smoking and tobacco use, among the specific US states that experienced short-term increases in oral cancer incidence and mortality. Methods Population-based data on oral cancer morbidity and mortality in the US were obtained from the National Cancer Institute's (NCI Surveillance, Epidemiology, and End Results (SEER database for analysis of recent trends. Data were also obtained from the Centers for Disease Control and Prevention (CDC Behavioral Risk Factor Surveillance System (BRFSS to measure current and former trends of tobacco usage. To comprehensive measures of previous state tobacco use and tobacco-related policies, the Initial Outcomes Index (IOI, 1992-1993 and the Strength of Tobacco Control index (SoTC, 1999-2000 were also used for evaluation and comparison. Results Analysis of the NCI-SEER data confirmed a previous report of geographic increases in oral cancer and demonstrated these were state-specific, were not regional, and were unrelated to previously observed increases among females and minorities. Analysis of the CDC-BRFSS data revealed these states had relatively higher percentages of smokers currently, as well as historically. In addition, analysis of the IOI and SoTC indexes suggest that many factors, including cigarette pricing, taxes and home or workplace bans, may have had significant influence on smoking prevalence in these areas. Trend analysis of these data uncovered a recent and significant reversal in smoking rates that suggest oral cancer incidence and mortality may also begin to decline in the near future. Conclusion Due to the rising costs of health care in the US and the limited resources available for health prevention efforts, it is essential to organize and direct more effective efforts by public health officials and epidemiologists, as well as funding from local, state and federal governments, to reduce and eliminate identified

  15. Diagnostic accuracy of 64-slice computed tomography coronary angiography for the detection of in-stent restenosis: A meta-analysis

    NARCIS (Netherlands)

    N. Carrabba (Nazario); J.D. Schuijf (Joanne); F.R. de Graaf (Fleur); G. Parodi (Guido); E. Maffei (Erica); R. Valenti (Renato); A. Palumbo (Alessandro); A.C. Weustink (Annick); N.R.A. Mollet (Nico); G. Accetta (Gabriele); F. Cademartiri (Filippo); D. Antoniucci (David); J.J. Bax (Jeroen)

    2010-01-01

    textabstractBackground: We sought to evaluate the diagnostic accuracy of 64-slice multi-detector row computed tomography (MDCT) compared with invasive coronary angiography for in-stent restenosis (ISR) detection. Methods: MEDLINE, Cochrane library, and BioMed Central database searches were performed

  16. Accuracy of intraoperative consultation in thyroid nodules: analysis of 2,040 cases performed at Instituto Nacional de Câncer in 12 years

    Directory of Open Access Journals (Sweden)

    Theresinha C. Fonseca

    2015-10-01

    Full Text Available ABSTRACTIntroduction:The thyroid nodule is the most common clinical manifestation of thyroid diseases, and, among the procedures for its diagnosis, cytological examination is the most used. Due to the high accuracy of cytological examination, the value of intraoperative consultation (IOC has become a matter of controversy. IOC is one of the most important and difficult procedures that a pathologist adopts, enabling the patient to be diagnosed, treated and staged in the same intervention.Objective:To evaluate the accuracy of IOC in thyroid at Instituto Nacional de Câncer (Inca.Methods:This study analyzed IOC in thyroid held in Inca from January 2001 to December 2012. The IOC diagnosis was compared with the histopathologic diagnosis, considered the gold standard, and was classified as concordant, discordant and indeterminate. From these data we calculated sensitivity, specificity and accuracy.Results:Among the 2,040 held IOCs, diagnoses were concordant in 1,770 cases (87%, discordant in 45 (2% and indeterminate in 225 (11%. Among the 1,770 concordant cases, 1,252 (61% were true negative, and 518 (25%, true positive. Among the 45 discordant cases, 38 (2% were false negative, and seven (0,3%, false positive. The test sensitivity was 0.94%, specificity of 0.99% and accuracy of 0.97%.Conclusion:Our results indicate that IOC in thyroid is a highly accurate test, contributing to the surgical conduct.

  17. High Birth Weight Increases the Risk for Bone Tumor: A Systematic Review and Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Songfeng Chen

    2015-09-01

    Full Text Available There have been several epidemiologic studies on the relationship between high birth weight and the risk for bone tumor in the past decades. However, due to the rarity of bone tumors, the sample size of individual studies was generally too small for reliable conclusions. Therefore, we have performed a meta-analysis to pool all published data on electronic databases with the purpose to clarify the potential relationship. According to the inclusion and exclusion criteria, 18 independent studies with more than 2796 cases were included. As a result, high birth weight was found to increase the risk for bone tumor with an Odds Ratio (OR of 1.13, with the 95% confidence interval (95% CI ranging from 1.01 to 1.27. The OR of bone tumor for an increase of 500 gram of birth weight was 1.01 (95% CI 1.00–1.02; p = 0.048 for linear trend. Interestingly, individuals with high birth weight had a greater risk for osteosarcoma (OR = 1.22, 95% CI 1.06–1.40, p = 0.006 than those with normal birth weight. In addition, in the subgroup analysis by geographical region, elevated risk was detected among Europeans (OR = 1.14, 95% CI 1.00–1.29, p = 0.049. The present meta-analysis supported a positive association between high birth weight and bone tumor risk.

  18. Cooperative genome-wide analysis shows increased homozygosity in early onset Parkinson's disease.

    Directory of Open Access Journals (Sweden)

    Javier Simón-Sánchez

    Full Text Available Parkinson's disease (PD occurs in both familial and sporadic forms, and both monogenic and complex genetic factors have been identified. Early onset PD (EOPD is particularly associated with autosomal recessive (AR mutations, and three genes, PARK2, PARK7 and PINK1, have been found to carry mutations leading to AR disease. Since mutations in these genes account for less than 10% of EOPD patients, we hypothesized that further recessive genetic factors are involved in this disorder, which may appear in extended runs of homozygosity.We carried out genome wide SNP genotyping to look for extended runs of homozygosity (ROHs in 1,445 EOPD cases and 6,987 controls. Logistic regression analyses showed an increased level of genomic homozygosity in EOPD cases compared to controls. These differences are larger for ROH of 9 Mb and above, where there is a more than three-fold increase in the proportion of cases carrying a ROH. These differences are not explained by occult recessive mutations at existing loci. Controlling for genome wide homozygosity in logistic regression analyses increased the differences between cases and controls, indicating that in EOPD cases ROHs do not simply relate to genome wide measures of inbreeding. Homozygosity at a locus on chromosome19p13.3 was identified as being more common in EOPD cases as compared to controls. Sequencing analysis of genes and predicted transcripts within this locus failed to identify a novel mutation causing EOPD in our cohort.There is an increased rate of genome wide homozygosity in EOPD, as measured by an increase in ROHs. These ROHs are a signature of inbreeding and do not necessarily harbour disease-causing genetic variants. Although there might be other regions of interest apart from chromosome 19p13.3, we lack the power to detect them with this analysis.

  19. Failure Mode and Effect Analysis in Increasing the Revenue of Emergency Department

    Directory of Open Access Journals (Sweden)

    Farhad Rahmati

    2015-02-01

    Full Text Available Introduction: Successful performance of emergency department(ED is one of the important indications of increasing the satisfaction among referees. The insurance of such successful performance is fiscal discipline and avoiding from non-beneficial activities in this department. Therefore, the increasing revenue of emergency department is one of the interested goals of hospital management system. According to above-mentioned, the researchers assessed problems lead to loss the revenue of ED and eliminate them by using failure mode and effects analysis (FMEA.Methods: This was the prospective cohort study performed during 18 months, set in 6 phases. In the first phase, the failures were determined and some solutions suggested to eliminate them. During 2-5 phases, based on the prioritizing the problems, solutions were performed. In the sixth phase, final assessment of the study was done. Finally, the feedback of system’s revenue was evaluated and data analyzed using repeated measure ANOVA.Results: Lack of recording the consuming instrument and attribution of separate codes for emergency services of hospitalized patients were the most important failures that lead to decrease the revenue of ED. Such elimination caused to 75.9% increase in revenue within a month (df = 1.6; F = 84.0; p<0.0001.  Totally, 18 months following the eliminating of failures caused to 328.2% increase in the revenue of ED (df = 15.9; F = 215; p<0.0001.Conclusion: The findings of the present study shows that failure mode and effect analysis, can be used as a safe and effected method to reduce the expenses of ED and increase its revenue.

  20. Why did China's energy intensity increase during 1998-2006: Decomposition and policy analysis

    International Nuclear Information System (INIS)

    Despite the fact that China's energy intensity has continuously decreased during the 1980s and mostly 1990s, the decreasing trend has reversed since 1998 and the past few years have witnessed rapid increase in China's energy intensity. We firstly conduct an index decomposition analysis to identify the key forces behind the increase. It is found that: (1) the high energy demand in industrial sectors is mainly attributed to expansion of production scale, especially in energy-intensive industries; (2) energy saving mainly comes from efficiency improvement, with energy-intensive sectors making the largest contribution; and (3) a heavier industrial structure also contributes to the increase. This study also makes the first attempt to bridge the quantitative decomposition analysis with qualitative policy analyses and fill the gap between decomposition results and policy relevance in previous work. We argue that: (1) energy efficiency improvement in energy-intensive sectors is mainly due to the industrial policies that have been implemented in the past few years; (2) low energy prices have directly contributed to high industrial energy consumption and indirectly to the heavy industrial structure. We provide policy suggestions in the end.

  1. VALUE CHAIN ANALYSIS OF BROILER TO INCREASE COMPETITIVENESS (Case Study at PT. Charoen Pokphand Indonesia, Tbk

    Directory of Open Access Journals (Sweden)

    Surip Prayugo

    2012-09-01

    Full Text Available The objectives of this research are to (1 map the value chain in broiler at PT. Charoen Pokphand Indonesia, Tbk (CPI; (2 analyze the value chain governance in broiler at CPI; (3 analyze the margin of marketing at broiler industry both on farm or off farm; (3 analyze the gap between the expectation and the performance of consumers (farmers upon using products of CPI and (4 recognize factors influencing competitiveness in broiler industry; and (5 to formulate strategy for value chain upgrading at CPI in order to increase competitiveness of broiler. As revealed by the value chain analysis, the role of CPI in this value chain is highly significant. All poultry inputs (DOC, feed, veterinary medicine, and poultry equipments are supplied by CPI. As for downstream sector, CPI processes broiler into its derivatives. The type of value chain governance between feed supplier, DOC, and veterinary medicine, poultry equipment, and poultry derivates belongs to market value chain. Whereas the type of value chain governance between carcass supplier and restaurant belongs to captive value chain. Based on the margin of marketing analysis, the party that gains the lowest margin is farmer and the party that receives the highest margin is the processor. In gap analysis, the lowest attribute of competitiveness is the feed spending and the highest attribute is the spending on veterinary medicine for two months. Factors that influence the competitiveness in poultry industry are condition, demand, industry competition, main industries and supporting industries, and government’s role.Keywords: Value Chain, Competitiveness, Broiler, PT. Charoen Pokphand Indonesia, Tbk, Margin of Marketing Analysis, Gap Analysis, SWOT Analysis

  2. Increasing Supply-Chain Visibility with Rule-Based RFID Data Analysis

    DEFF Research Database (Denmark)

    Ilic, A.; Andersen, Thomas; Michahelles, F.

    2009-01-01

    RFID technology tracks the flow of physical items and goods in supply chains to help users detect inefficiencies, such as shipment delays, theft, or inventory problems. An inevitable consequence, however, is that it generates huge numbers of events. To exploit these large amounts of data, the Sup......RFID technology tracks the flow of physical items and goods in supply chains to help users detect inefficiencies, such as shipment delays, theft, or inventory problems. An inevitable consequence, however, is that it generates huge numbers of events. To exploit these large amounts of data......, the Supply Chain Visualizer increases supply-chain visibility by analyzing RFID data, using a mix of automated analysis techniques and human effort. The tool's core concepts include rule-based analysis techniques and a map-based representation interface. With these features, it lets users visualize...

  3. Systematic reviews of diagnostic test accuracy.

    Science.gov (United States)

    Leeflang, Mariska M G; Deeks, Jonathan J; Gatsonis, Constantine; Bossuyt, Patrick M M

    2008-12-16

    More and more systematic reviews of diagnostic test accuracy studies are being published, but they can be methodologically challenging. In this paper, the authors present some of the recent developments in the methodology for conducting systematic reviews of diagnostic test accuracy studies. Restrictive electronic search filters are discouraged, as is the use of summary quality scores. Methods for meta-analysis should take into account the paired nature of the estimates and their dependence on threshold. Authors of these reviews are advised to use the hierarchical summary receiver-operating characteristic or the bivariate model for the data analysis. Challenges that remain are the poor reporting of original diagnostic test accuracy studies and difficulties with the interpretation of the results of diagnostic test accuracy research.

  4. A Western Dietary Pattern Increases Prostate Cancer Risk: A Systematic Review and Meta-Analysis

    Science.gov (United States)

    Fabiani, Roberto; Minelli, Liliana; Bertarelli, Gaia; Bacci, Silvia

    2016-01-01

    Dietary patterns were recently applied to examine the relationship between eating habits and prostate cancer (PC) risk. While the associations between PC risk with the glycemic index and Mediterranean score have been reviewed, no meta-analysis is currently available on dietary patterns defined by “a posteriori” methods. A literature search was carried out (PubMed, Web of Science) to identify studies reporting the relationship between dietary patterns and PC risk. Relevant dietary patterns were selected and the risks estimated were calculated by a random-effect model. Multivariable-adjusted odds ratios (ORs), for a first-percentile increase in dietary pattern score, were combined by a dose-response meta-analysis. Twelve observational studies were included in the meta-analysis which identified a “Healthy pattern” and a “Western pattern”. The Healthy pattern was not related to PC risk (OR = 0.96; 95% confidence interval (CI): 0.88–1.04) while the Western pattern significantly increased it (OR = 1.34; 95% CI: 1.08–1.65). In addition, the “Carbohydrate pattern”, which was analyzed in four articles, was positively associated with a higher PC risk (OR = 1.64; 95% CI: 1.35–2.00). A significant linear trend between the Western (p = 0.011) pattern, the Carbohydrate (p = 0.005) pattern, and the increment of PC risk was observed. The small number of studies included in the meta-analysis suggests that further investigation is necessary to support these findings. PMID:27754328

  5. Do Increased Resources Increase Educational Attainment during a Period of Rising Expenditure? Evidence from English Secondary Schools Using a Dynamic Panel Analysis

    Science.gov (United States)

    Pugh, Geoff; Mangan, Jean; Gray, John

    2011-01-01

    This article estimates the effects of school expenditure on school performance at Key Stage 4 in England, over the period 2003-07 during which real per pupil expenditure increased rapidly. It adds to previous investigations by using dynamic panel analysis to: exploit time series data on individual schools that only recently has become available;…

  6. Riparian plant community responses to increased flooding: a meta-analysis.

    Science.gov (United States)

    Garssen, Annemarie G; Baattrup-Pedersen, Annette; Voesenek, Laurentius A C J; Verhoeven, Jos T A; Soons, Merel B

    2015-08-01

    A future higher risk of severe flooding of streams and rivers has been projected to change riparian plant community composition and species richness, but the extent and direction of the expected change remain uncertain. We conducted a meta-analysis to synthesize globally available experimental evidence and assess the effects of increased flooding on (1) riparian adult plant and seedling survival, (2) riparian plant biomass and (3) riparian plant species composition and richness. We evaluated which plant traits are of key importance for the response of riparian plant species to flooding. We identified and analysed 53 papers from ISI Web of Knowledge which presented quantitative experimental results on flooding treatments and corresponding control situations. Our meta-analysis demonstrated how longer duration of flooding, greater depth of flooding and, particularly, their combination reduce seedling survival of most riparian species. Plant height above water level, ability to elongate shoots and plasticity in root porosity were decisive for adult plant survival and growth during longer periods of flooding. Both 'quiescence' and 'escape' proved to be successful strategies promoting riparian plant survival, which was reflected in the wide variation in survival (full range between 0 and 100%) under fully submerged conditions, while plants that protrude above the water level (>20 cm) almost all survive. Our survey confirmed that the projected increase in the duration and depth of flooding periods is sufficient to result in species shifts. These shifts may lead to increased or decreased riparian species richness depending on the nutrient, climatic and hydrological status of the catchment. Species richness was generally reduced at flooded sites in nutrient-rich catchments and sites that previously experienced relatively stable hydrographs (e.g. rain-fed lowland streams). Species richness usually increased at sites in desert and semi-arid climate regions (e.g. intermittent

  7. Obesity increases operating room times in patients undergoing primary hip arthroplasty: a retrospective cohort analysis.

    Science.gov (United States)

    Kadry, Bassam; Press, Christopher D; Alosh, Hassan; Opper, Isaac M; Orsini, Joe; Popov, Igor A; Brodsky, Jay B; Macario, Alex

    2014-01-01

    Background. Obesity impacts utilization of healthcare resources. The goal of this study was to measure the relationship between increasing body mass index (BMI) in patients undergoing total hip arthroplasty (THA) with different components of operating room (OR) time. Methods. The Stanford Translational Research Integrated Database Environment (STRIDE) was utilized to identify all ASA PS 2 or 3 patients who underwent primary THA at Stanford Medical Center from February 1, 2008 through January 1, 2013. Patients were divided into five groups based on the BMI weight classification. Regression analysis was used to quantify relationships between BMI and the different components of total OR time. Results. 1,332 patients were included in the study. There were no statistically significant differences in age, gender, height, and ASA PS classification between the BMI groups. Normal-weight patients had a total OR time of 138.9 min compared 167.9 min (P 35 kg/m(2) each incremental BMI unit increase was associated with greater incremental total OR time increases. Conclusion. Morbidly obese patients required significantly more total OR time than normal-weight patients undergoing a THA procedure. This increase in time is relevant when scheduling obese patients for surgery and has an important impact on health resource utilization.

  8. Obesity increases operating room times in patients undergoing primary hip arthroplasty: a retrospective cohort analysis

    Directory of Open Access Journals (Sweden)

    Bassam Kadry

    2014-08-01

    Full Text Available Background. Obesity impacts utilization of healthcare resources. The goal of this study was to measure the relationship between increasing body mass index (BMI in patients undergoing total hip arthroplasty (THA with different components of operating room (OR time. Methods. The Stanford Translational Research Integrated Database Environment (STRIDE was utilized to identify all ASA PS 2 or 3 patients who underwent primary THA at Stanford Medical Center from February 1, 2008 through January 1, 2013. Patients were divided into five groups based on the BMI weight classification. Regression analysis was used to quantify relationships between BMI and the different components of total OR time. Results. 1,332 patients were included in the study. There were no statistically significant differences in age, gender, height, and ASA PS classification between the BMI groups. Normal-weight patients had a total OR time of 138.9 min compared 167.9 min (P 35 kg/m2 each incremental BMI unit increase was associated with greater incremental total OR time increases. Conclusion. Morbidly obese patients required significantly more total OR time than normal-weight patients undergoing a THA procedure. This increase in time is relevant when scheduling obese patients for surgery and has an important impact on health resource utilization.

  9. Qualitative analysis of factors that increase and reduce involvement in gambling

    Directory of Open Access Journals (Sweden)

    Egidijus

    2015-12-01

    Full Text Available During the rapid development of gambling business, the number of pathological gamblers is increasing as well. The problem of pathological gambling is just as important as alcoholism or drug addiction. However, there is a lack of information and research of this topicin Lithuania. The aim of work: to investigate and analyse the factors that increase or reduce involvement in gambling. Research questions: 1 What factors increase involvement in gambling? 2 What factors reduce involvement in gambling? Critical case sampling was used for selection of the participants. Subjects were required to a have experience of involvement in gambling for at least one year; b have experience of negative impact of gambling on quality of life; c have at least 6 months of gambling abstinence. Five individuals participated in the research; all of them were males who live in Vilnius. Age of the participants varied from 19 to 45. Semi-structured interviews were used to collect data. Interviews were recorded and transcribed verbatim. The matic analysis of the data led to the identification of four major the matic categories: psychological factors; social relations; material well being; quality of life. There search results show that negatyve childhood experience, gambling friends, escaping from various troubles, disputes in family and high financial needs can increase involvement in gambling. Factors that reduce involvement in gambling are: feeling support of social environment, proper evaluation of financial position, awareness of one‘s own addiction to gambling and desire to change life.

  10. Analysis of the accuracy of Shuttle Radar Topography Mission (SRTM) height models using International Global Navigation Satellite System Service (IGS) Network

    Indian Academy of Sciences (India)

    Manas Mukul; Vinee Srivastava; Malay Mukul

    2015-08-01

    The Shuttle Radar Topography Mission (SRTM) carried out in February 2000 has provided near global topographic data that has been widely used in many fields of earth sciences. The mission goal of an absolute vertical accuracy within 16 m (with 90% confidence)/RMSE ∼10 m was achieved based on ground validation of SRTM data through various studies using global positioning system (GPS). We present a new and independent assessment of the vertical accuracy of both the X- and C-band SRTM datasets using data from the International GNSS Service (IGS) network of high-precision static GPS stations. These stations exist worldwide, have better spatial distribution than previous studies, have a vertical accuracy of 6 mm and constitute the most accurate ground control points (GCPs) possible on earth; these stations are used as fiducial stations to define the International Terrestrial Reference Frame (ITRF). Globally, for outlier-filtered data (135 X-band stations and 290 C-band stations), the error or difference between IGS and SRTM heights exhibits a non-normal distribution with a mean and standard error of 8.2 ± 0.7 and 6.9 ± 0.5 m for X- and C-band data, respectively. Continent-wise, Africa, Australia and North America comply with the SRTM mission absolute vertical accuracy of 16 m (with 90% confidence)/RMSE ∼10 m. However, Asia, Europe and South America have vertical errors higher than the SRTM mission goal. At stations where both the X- and C-band SRTM data were present, the root mean square error (RMSE) of both the X- and C-bands was identical at 11.5 m, indicating similar quality of both the X- and C-band SRTM data.

  11. Dual-energy CT angiography in peripheral arterial occlusive disease - accuracy of maximum intensity projections in clinical routine and subgroup analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kau, Thomas [Klinikum Klagenfurt, General Hospital of Klagenfurt, Institute of Diagnostic and Interventional Radiology, Klagenfurt (Austria); Klinikum Klagenfurt am Worthersee, Radiologie, Klagenfurt (Austria); Eicher, Wolfgang; Reiterer, Christian; Niedermayer, Martin; Rabitsch, Egon; Hausegger, Klaus A. [Klinikum Klagenfurt, General Hospital of Klagenfurt, Institute of Diagnostic and Interventional Radiology, Klagenfurt (Austria); Senft, Birgit [Section of Statistics, Reha Clinic for Mental Health, Klagenfurt (Austria)

    2011-08-15

    To evaluate the accuracy of dual-energy CT angiography (DE-CTA) maximum intensity projections (MIPs) in symptomatic peripheral arterial occlusive disease (PAOD). In 58 patients, DE-CTA of the lower extremities was performed on dual-source CT. In a maximum of 35 arterial segments, severity of the most stenotic lesion was graded (<10%, 10-49% and 50-99% luminal narrowing or occlusion) independently by two radiologists, with DSA serving as the reference standard. In DSA, 52.3% of segments were significantly stenosed or occluded. Agreement of DE-CTA MIPs with DSA was good in the aorto-iliac and femoro-popliteal regions ({kappa} = 0.72; {kappa} = 0.66), moderate in the crural region ({kappa} = 0.55), slight in pedal arteries ({kappa} = 0.10) and very good in bypass segments ({kappa} = 0.81). Accuracy was 88%, 78%, 74%, 55% and 82% for the respective territories and moderate (75%) overall, with good sensitivity (84%) and moderate specificity (67%). Sensitivity and specificity was 82% and 76% in claudicants and 84% and 61% in patients with critical limb ischaemia. While correlating well with DSA above the knee, accuracy of DE-CTA MIPs appeared to be moderate in the calf and largely insufficient in calcified pedal arteries, especially in patients with critical limb ischaemia. (orig.)

  12. GPS单点测速的误差分析及精度评价%Error Analysis and Accuracy Assessment of GPS Absolute Velocity Determination without SA

    Institute of Scientific and Technical Information of China (English)

    王甫红; 张小红; 黄劲松

    2008-01-01

    Error sources which decrease the accuracy of GPS in absolute velocity determination have been changed since SA was turned off. Firstly, quantities of all kinds of error sources that influence velocity determination are analyzed. The potential accuracy of GPS absolute velocity determination is derived from both theory and field GPS data simulation. After that, two tests were carried out to evaluate the performance of GPS absolute velocity determination in the case of a static and an airborne GPS receiver and INS (Inertial Navigation System) instrument in kinematic mode. In static mode, the receiver velocity has been estimated to be several mm/s with the carrier-phase derived Doppler measurements, and several cm/s with the receiver generated Doppler measurements. In kinematic mode, GPS absolute velocity estimates are compared with the synchronized measurements from the high accuracy INS. The root mean square statistics of the velocity discrepancies between GPS and INS come up to dm/s. Moreover, it has a strong correlation with the acceleration or jerk of the aircraft.

  13. Empirical Analysis on Effect of Agricultural Financial Investment on Increase of Farmers’ Income

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    On the basis of economic data from 1978 to 2006,the co-integration theory is applied to discuss the relation between agricultural financial investment and farmers’ income.The statistic AR model is obtained.Then,it makes pulse response analysis in combination with principle of pulse response analysis.The regression results show that support in agricultural production,various agricultural operating expenses and three types of costs for agricultural science and technology are favorable to farmers’ income,while expenditure in agricultural capital construction and rural relief costs hinder increase of farmers’ income.The results of pulse response analysis indicate that the change in support of agricultural production and various agricultural operating expenses have positive impact on farmers’ net income,and the impact is greater and greater from the second year;the response of expenditure in agricultural capital construction and rural relief cost is positive in the beginning and starts to fluctuate from the third year;the pulse response of three types of costs for agricultural science and technology is negative,lasts about five periods,and then turns to positive impact.Finally,combining characteristics of China’s financial support for agriculture,it concludes that the scale,proportion and structure of financial support for agriculture are quite improper.

  14. Meta-analysis of internet-delivered interventions to increase physical activity levels

    Directory of Open Access Journals (Sweden)

    Davies Cally A

    2012-04-01

    Full Text Available Abstract Many internet-delivered physical activity behaviour change programs have been developed and evaluated. However, further evidence is required to ascertain the overall effectiveness of such interventions. The objective of the present review was to evaluate the effectiveness of internet-delivered interventions to increase physical activity, whilst also examining the effect of intervention moderators. A systematic search strategy identified relevant studies published in the English-language from Pubmed, Proquest, Scopus, PsychINFO, CINHAL, and Sport Discuss (January 1990 – June 2011. Eligible studies were required to include an internet-delivered intervention, target an adult population, measure and target physical activity as an outcome variable, and include a comparison group that did not receive internet-delivered materials. Studies were coded independently by two investigators. Overall effect sizes were combined based on the fixed effect model. Homogeneity and subsequent exploratory moderator analysis was undertaken. A total of 34 articles were identified for inclusion. The overall mean effect of internet-delivered interventions on physical activity was d = 0.14 (p = 0.00. Fixed-effect analysis revealed significant heterogeneity across studies (Q = 73.75; p = 0.00. Moderating variables such as larger sample size, screening for baseline physical activity levels and the inclusion of educational components significantly increased intervention effectiveness. Results of the meta-analysis support the delivery of internet-delivered interventions in producing positive changes in physical activity, however effect sizes were small. The ability of internet-delivered interventions to produce meaningful change in long-term physical activity remains unclear.

  15. TRACE analysis of Phenix core response to an increase of the core inlet sodium temperature

    International Nuclear Information System (INIS)

    This work presents the analysis, using the TRACE code, of the Phenix core response to an inlet sodium temperature increase. The considered experiment was performed in the frame of the Phenix End-Of-Life (EOL) test program of the CEA, prior to the final shutdown of the reactor. It corresponds to a transient following a 40°C increase of the core inlet temperature, which leads to a power decrease of 60%. This work focuses on the first phase of the transient, prior to the reactor scram and pump trip. First, the thermal-hydraulic TRACE model of the core developed for the present analysis is described. The kinetic parameters and feedback coefficients for the point kinetic model were first derived from a 3D static neutronic ERANOS model developed in a former study. The calculated kinetic parameters were then optimized, before use, on the basis of the experimental reactivity in order to minimize the error on the power calculation. The different reactivity feedbacks taken into account include various expansion mechanisms that have been specifically implemented in TRACE for analysis of fast-neutron spectrum systems. The point kinetic model has been used to study the sensitivity of the core response to the different feedback effects. The comparison of the calculated results with the experimental data reveals the need to accurately calculate the reactivity feedback coefficients. This is because the reactor response is very sensitive to small reactivity changes. This study has enabled us to study the sensitivity of the power change to the different reactivity feedbacks and define the most important parameters. As such, it furthers the validation of the FAST code system, which is being used to gain a more in-depth understanding of SFR core behavior during accidental transients. (author)

  16. Why the increase in under five mortality in Uganda from 1995 to 2000? A retrospective analysis

    Directory of Open Access Journals (Sweden)

    Ayiga Natal

    2011-09-01

    Full Text Available Abstract Background From 1995-2000 the under five mortality rate in Uganda increased from 147.3 to 151.5 deaths per 1000 live births and reasons for the increase were not clear. This study was undertaken to understand factors influencing the increase in under five mortality rate during 1995-2000 in Uganda with a view of suggesting remedial actions. Methods We performed a comparative retrospective analysis of data derived from the 1995 and the 2000 Uganda demographic and health surveys. We correlated the change of under five mortality rate in Uganda desegregated by region (central, eastern, north and western with change in major known determinants of under five mortality such social economic circumstances, maternal factors, access to health services, and level of nutrition. Results The increase in under five mortality rate only happened in western Uganda with the other 3 regions of Uganda (eastern, northern and central showing a decrease. The changes in U5MR could not be explained by changes in poverty, maternal conditions, level of nutrition, or in access to health and other social services and in the prevalence of HIV among women attending for ante-natal care. All these factors did not reach statistical significance (P > 0.05 using Pearson's correlation coefficient. Conclusion In order to explain these findings, there is need to find something that happened in western Uganda (but not other parts of the country during the period 1995-2000 and has the potential to change the under five mortality by a big margin. We hypothesize that the increase in under five mortality could be explained by the severe malaria epidemic that occurred in western Uganda (but not other regions in 1997/98.

  17. Accuracy of depolarization and delay spread predictions using advanced ray-based modeling in indoor scenarios

    Directory of Open Access Journals (Sweden)

    Mani Francesco

    2011-01-01

    Full Text Available Abstract This article investigates the prediction accuracy of an advanced deterministic propagation model in terms of channel depolarization and frequency selectivity for indoor wireless propagation. In addition to specular reflection and diffraction, the developed ray tracing tool considers penetration through dielectric blocks and/or diffuse scattering mechanisms. The sensitivity and prediction accuracy analysis is based on two measurement campaigns carried out in a warehouse and an office building. It is shown that the implementation of diffuse scattering into RT significantly increases the accuracy of the cross-polar discrimination prediction, whereas the delay-spread prediction is only marginally improved.

  18. Education increases reserve against Alzheimer's disease - evidence from structural MRI analysis

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yawu [University of Eastern Finland, Kuopio University Hospital, Department of Neurology, P.O.Box 1627, Kuopio (Finland); University of Eastern Finland, Kuopio University Hospital, Department of Clinical Radiology, Kuopio (Finland); Julkunen, Valtteri; Paajanen, Teemu; Soininen, Hilkka [University of Eastern Finland, Kuopio University Hospital, Department of Neurology, P.O.Box 1627, Kuopio (Finland); Westman, Eric; Wahlund, Lars-Olof [Karolinska Institutet, Department of Neurobiology, Care Sciences and Society, Section of Clinical Geriatrics, Stockholm (Sweden); Aitken, Andrew [South London and Maudsley NHS Foundation Trust and King' s College London, NIHR Biomedical Research Centre for Mental Health, London (United Kingdom); Sobow, Tomasz [Medical University of Lodz, Department of Old Age Psychiatry and Psychotic Disorders, Lodz (Poland); Mecocci, Patrizia [University of Perugia, Institute of Gerontology and Geriatrics, Perugia (Italy); Tsolaki, Magda [Aristotle University of Thessaloniki, Third Department of Neurology, Thessaloniki (Greece); Vellas, Bruno [Universite Paul Sabatier, INSERM U 558, Toulouse Gerontopole University Hospital, Toulouse (France); Muehlboeck, Sebastian [McGill University, McConnell Brain Imaging Center, Montreal (Canada); Spenger, Christian [Karolinska Institutet, Department of Clinical Science, Intervention and Technology, Stockholm (Sweden); Lovestone, Simon; Simmons, Andrew [South London and Maudsley NHS Foundation Trust and King' s College London, NIHR Biomedical Research Centre for Mental Health, London (United Kingdom); King' s College London, MRC Centre for Neurodegeneration Research, Institute of Psychiatry, London (United Kingdom); Collaboration: AddNeuroMed Consortium

    2012-09-15

    The aim of this study was to determine whether years of schooling influences regional cortical thicknesses and volumes in Alzheimer's disease (AD), mild cognitive impairment (MCI), and healthy age-matched controls. Using an automated image analysis pipeline, 33 regional cortical thickness and 15 regional volumes measures from MRI images were determined in 121 subjects with MCI, 121 patients with AD, and 113 controls from AddNeuroMed study. Correlations with years of schooling were determined and more highly and less highly educated subjects compared, controlling for intracranial volume, age, gender, country of origin, cognitive status, and multiple testing. After controlling for confounding factors and multiple testing, in the control group, subjects with more education had larger regional cortical thickness in transverse temporal cortex, insula, and isthmus of cingulate cortex than subjects with less education. However, in the AD group, the subjects with more education had smaller regional cortical thickness in temporal gyrus, inferior and superior parietal gyri, and lateral occipital cortex than the subjects with less education. No significant difference was found in the MCI group. Education may increase regional cortical thickness in healthy controls, leading to increased brain reserve, as well as helping AD patients to cope better with the effects of brain atrophy by increasing cognitive reserve. (orig.)

  19. Education increases reserve against Alzheimer's disease - evidence from structural MRI analysis

    International Nuclear Information System (INIS)

    The aim of this study was to determine whether years of schooling influences regional cortical thicknesses and volumes in Alzheimer's disease (AD), mild cognitive impairment (MCI), and healthy age-matched controls. Using an automated image analysis pipeline, 33 regional cortical thickness and 15 regional volumes measures from MRI images were determined in 121 subjects with MCI, 121 patients with AD, and 113 controls from AddNeuroMed study. Correlations with years of schooling were determined and more highly and less highly educated subjects compared, controlling for intracranial volume, age, gender, country of origin, cognitive status, and multiple testing. After controlling for confounding factors and multiple testing, in the control group, subjects with more education had larger regional cortical thickness in transverse temporal cortex, insula, and isthmus of cingulate cortex than subjects with less education. However, in the AD group, the subjects with more education had smaller regional cortical thickness in temporal gyrus, inferior and superior parietal gyri, and lateral occipital cortex than the subjects with less education. No significant difference was found in the MCI group. Education may increase regional cortical thickness in healthy controls, leading to increased brain reserve, as well as helping AD patients to cope better with the effects of brain atrophy by increasing cognitive reserve. (orig.)

  20. 差分GPS应用于机载雷达精度统计的方法研究%Airborne Radar Accuracy Statistical Analysis Method Based on Differential GPS

    Institute of Scientific and Technical Information of China (English)

    牟聪; 王伟; 张明

    2012-01-01

    为满足机载雷达在定型试验中通常要面对跟踪精度分析这一重要技术指标的需求,通过差分GPS应用于该指标考核的可用性分析,结合相关的国家军用标准,构建了基于差分GPS的机载雷达跟踪精度统计分析方法,并通过在某型机载雷达定型试飞中的应用,验证了方法的可行性和正确性。%To satisfy the demand for tracking accuracy analysis during approval test of airborne radar,an accuracy statistical analysis method based on differential GPS for airborne radar is proposed through feasibility analysis of differential GPS applied in airborne radar accuracy check and combining of related military standards.Practical application of this method in approval flight test of some airborne radar verified that this method is feasible and correct.

  1. Spectral Analysis of the Signals Associated with Increased Activity in Popocatepetl Volcano April 2012

    Science.gov (United States)

    Cuenca, J.

    2013-05-01

    After several decades of being inactive in 1994 had a strong reactivation. Since then he has had long periods where volcanic activity including increased growth and destruction of a dome. In April 2012 Popocatepetl Volcano activity showed an increase in the emission of gas and ash, and Vulcanian type explosions. As a result the National Center for Disaster Prevention (CENAPRED) raised the yellow phase from 2 to 3. Spectrally analyzes seismic activity characteristic of the types of events (explosions, LP, Type-B and tremors) that provides information of the source processes that cause it, despite sustained change reflected by the complexity of the volcanic apparatus, through of: 1) the spectral content of the process provides the source, 2) the spectral ratio H / V, its associated amplification and dominant frequencies, 3) time frequency analysis showing the variation in frequency, 4) the particle motion to analyze its retrograde or prograde acting in a volcanic complex medium. The calculation of H / V was performed by each hour using windows with duration of 80 seconds in the broadband seismic station "Canario" (PPPB). The predominant frequencies of H / V are around 1.4-1.8 Hz to 2.1-2.6 Hz and amplifications from 2.3 to 6.9 times. Analysis of H / V of 48 hours (days 16 and April 17) for the case of 1.4-1.8 Hz was observed: (1) From 0-9 hours there is no amplification. (2) The seismic amplification increases from 10 to 11 hours. (3) A first crisis reaches a maximum at 13 hours with about 6 times of amplification. (4) From 14 to 15 hours there is a strong relaxation of the activity. (5) The activity begins to increase from 16 to 23 hours where it reaches its maximum amplification of almost 7 times. (6) The following two hours and is kept exceeding 6 times of amplification. (7) Then is followed by a decrease to 4 hours on the day 17, from which is maintained at a level variable. (8) At 18 hours of the day 17 grows the amplification at 6.2 times, which conforms a

  2. Increased Circulating MicroRNA-155 as a Potential Biomarker for Breast Cancer Screening: A Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Faliang Wang

    2014-05-01

    Full Text Available The objective of this meta-analysis was to determine the diagnostic accuracy of circulating microRNA-155 (miR-155 for breast cancer (BC. PubMed, Embase, EBSCO (ASP/BSP, Cochrane Library and China National Knowledge Infrastructure (CNKI were searched up to 30 January 2014 for eligible studies. Quality Assessment of Diagnostic Accuracy Studies (QUADAS was employed to assess the quality of the included studies. Meta-analysis were performed in Meta-Disc 1.4 and Stata 12.0. Three studies with total 184 BC patients and 75 control individuals were included in this meta-analysis. All of the included studies are of high quality (QUADAS scores 12 or 13. The summary estimates revealed that the pooled sensitivity is 79% (95% confidence interval (CI: 72%–84% and the specificity is 85% (95% CI: 75%–92%, for the diagnosis of breast cancer. In addition, the area under the summary ROC curve (AUC is 0.9217. The current evidence suggests that circulating miR-155 has the potential diagnostic value with a high sensitivity and specificity for BC. More prospective studies on the diagnostic value of circulating miR-155 for BC are needed in the future.

  3. Analysis of process related factors to increase volumetric productivity and quality of biomethane with Methanothermobacter marburgensis

    International Nuclear Information System (INIS)

    Highlights: • Biological methanogenesis with M. marburgensis was identified to be gas limited. • Volumetric productivity was increased by improving gas/liquid mass transfer. • Quantitative analysis of key parameters in gas/liquid mass transfer was demonstrated. • A systematic strategy for maximising productivity without quality loss is suggested. - Abstract: The biological conversion of H2 and CO2 into CH4, using methanogenic archaea is an interesting technology for CO2 conversion, energy storage and biogas upgrading. For an industrial application of this process however, the optimization of the volumetric productivity and the product quality is an important issue. Since the reactants in this fermentation process are, unlike in most microbial fermentations, solely gasses, the gas liquid mass transfer is supposed to play an important role on the way to a higher volumetric productivity. This work aimed at investigating the effects of the gassing rate, the reactor pressure, as well as reactor design issues on the performance of Methanothermobactermarburgensis by using continuous cultures. Our results show that biological methanogenesis with M. marburgensis is gas limited. Maximum physiological capacity is not reached yet. The gassing rate influenced mainly the volumetric methane production rate (MER), the reactor pressure influenced mainly the offgas quality. Based on this information, we demonstrated how a combination of increased gas flow rate and increased reactor pressure can be used to reach high volumetric productivity at high offgas quality. Maximum MER was 950 mmol L−1 h−1 at a CH4 concentration of 60 Vol.-%, maximum CH4 concentration reached was 85 Vol.-% at a MER of 255 mmol L−1 h−1. The reactor design currently limits further increase in gas flow rate and reactor pressure. Therefore Interdisciplinary bridges from bioprocessing to chemical reactor design must be followed in the future to boot this promising bioprocess to gain biomethane via

  4. Improving accuracy of holes honing

    Directory of Open Access Journals (Sweden)

    Ivan М. Buykli

    2015-03-01

    Full Text Available Currently, in precision engineering industry tolerances for linear dimensions and tolerances on shape of surfaces of processing parts are steadily tightened These requirements are especially relevant in processing of holes. Aim of the research is to improve accuracy and to enhance the technological capabilities of holes honing process and, particularly, of blind holes honing. Based on formal logic the analysis of formation of processing errors is executed on the basis of consideration of schemes of irregularity of dimensional wear and tear along the length of the cutting elements. With this, the possibilities of compensating this irregularities and, accordingly, of control of accuracy of processing applied to the honing of both throughout and blind holes are specified. At the same time, a new method of honing is developed, it is protected by the patent of Ukraine for invention. The method can be implemented both on an existing machine tools at insignificant modernization of its system of processing cycle control and on newly designed ones.

  5. Knowledge discovery by accuracy maximization.

    Science.gov (United States)

    Cacciatore, Stefano; Luchinat, Claudio; Tenori, Leonardo

    2014-04-01

    Here we describe KODAMA (knowledge discovery by accuracy maximization), an unsupervised and semisupervised learning algorithm that performs feature extraction from noisy and high-dimensional data. Unlike other data mining methods, the peculiarity of KODAMA is that it is driven by an integrated procedure of cross-validation of the results. The discovery of a local manifold's topology is led by a classifier through a Monte Carlo procedure of maximization of cross-validated predictive accuracy. Briefly, our approach differs from previous methods in that it has an integrated procedure of validation of the results. In this way, the method ensures the highest robustness of the obtained solution. This robustness is demonstrated on experimental datasets of gene expression and metabolomics, where KODAMA compares favorably with other existing feature extraction methods. KODAMA is then applied to an astronomical dataset, revealing unexpected features. Interesting and not easily predictable features are also found in the analysis of the State of the Union speeches by American presidents: KODAMA reveals an abrupt linguistic transition sharply separating all post-Reagan from all pre-Reagan speeches. The transition occurs during Reagan's presidency and not from its beginning.

  6. A literal analysis of potential interference from satellites with the proposed pfd increase

    Science.gov (United States)

    Jeske, Harold O.

    In this paper, an increase of 16 dB above current power flux density (pfd) limits for ITU Radio Regulations is proposed. The results of an analysis are reviewed which assumed worst case conditions for interference with telemetry operations at missile test ranges due to current and proposed satellite pfd levels. It was found that the performance of essentially all missile telemetry receiving systems may be appreciably degraded by even the lowest pfd limits currently permitted. For the higher pfd limits under consideration, degradation on the order of 40 dB is to be expected at stations with dish antennas only five feet in diameter. For satisfactory telemetry operation, the normal missile's telemetry received SNR would have to be well over 40 dB to overcome satellite interference. Several practical recommendations are made for missile and satellite telemetry to coexist in the 2200-2290 MHz band.

  7. Is increase in bone mineral content caused by increase in skeletal muscle mass/strength in adult patients with GH-treated GH deficiency? A systematic literature analysis

    DEFF Research Database (Denmark)

    Klefter, O.; Feldt-Rasmussen, U.

    2009-01-01

    performed a systematic literature analysis, including 51 clinical trials published between 1996 and 2008, which had studied the development in muscle mass, muscle strength, BMD, and/or BMC in GH-treated adult GHD patients. RESULTS: GH therapy had an anabolic effect on skeletal muscle. The largest increase...... from 1996 to 2008 suggest that the anabolic changes in muscle mass and strength may also contribute to changes in BMD/BMC in GH-treated adult GHD patients Udgivelsesdato: 2009/8...

  8. Differential SAGE analysis in Arabidopsis uncovers increased transcriptome complexity in response to low temperature

    Directory of Open Access Journals (Sweden)

    Parkin Isobel AP

    2008-09-01

    Full Text Available Abstract Background Abiotic stress, including low temperature, limits the productivity and geographical distribution of plants, which has led to significant interest in understanding the complex processes that allow plants to adapt to such stresses. The wide range of physiological, biochemical and molecular changes that occur in plants exposed to low temperature require a robust global approach to studying the response. We have employed Serial Analysis of Gene Expression (SAGE to uncover changes in the transcriptome of Arabidopsis thaliana over a time course of low temperature stress. Results Five SAGE libraries were generated from A. thaliana leaf tissue collected at time points ranging from 30 minutes to one week of low temperature treatment (4°C. Over 240,000 high quality SAGE tags, corresponding to 16,629 annotated genes, provided a comprehensive survey of changes in the transcriptome in response to low temperature, from perception of the stress to acquisition of freezing tolerance. Interpretation of these data was facilitated by representing the SAGE data by gene identifier, allowing more robust statistical analysis, cross-platform comparisons and the identification of genes sharing common expression profiles. Simultaneous statistical calculations across all five libraries identified 920 low temperature responsive genes, only 24% of which overlapped with previous global expression analysis performed using microarrays, although similar functional categories were affected. Clustering of the differentially regulated genes facilitated the identification of novel loci correlated with the development of freezing tolerance. Analysis of their promoter sequences revealed subsets of genes that were independent of CBF and ABA regulation and could provide a mechanism for elucidating complementary signalling pathways. The SAGE data emphasised the complexity of the plant response, with alternate pre-mRNA processing events increasing at low temperatures

  9. Increasing sensitivity of quasi-binary media analysis by spectral distribution of gamma-radiation albedo

    International Nuclear Information System (INIS)

    Full text: There has been suggested a method of increasing sensitivity of quasi-binary media analysis based on peculiarities of spectral distribution of gamma-radiation albedo. In quasi-binary media analysis in which there is observed close inter-connection between the effective coefficient of gamma-radiation weakening and heavy component content, it is necessary to obtain the maximum sensitivity of the analytical signal to the parameter being determined. The study showed that in certain geometrical parameters (source-detector distance, air gap between the probe and the medium surface) there is observed the spectrum displacement of the secondary radiation at the medium material composition change. The power distribution displacement of gamma-radiation albedo at the effective coefficient of gamma-radiation weakening change (the medium material composition) is explained by the adequate changing the length of free flight of primary quantum, angle characteristics of scattering and probability of photoelectric absorption of secondary radiation. The essence of the method suggested is in measuring the power corresponding to the maximum in the spectrum of the secondary radiation and the magnitude of gamma-radiation albedo. At the expense of these parameters change at the material composition of the medium analyzed variation there has been obtained the increase of the method contrast range. Depending on the type of the quasi-binary medium (coal, iron ore, carbonate raw materials) there have been determined optimal condition (primary radiation power, probe geometrical parameters) at which there is observed the maximum linear displacement of the power corresponding to the maximum in the secondary radiation spectrum and chosen the power intervals for normal magnitude of gamma-radiation albedo. The method is recommended to analyze raw and industrial materials of quasi-binary composition in which there is observed close correlation dependence between their effective atomic

  10. 单边直圆型柔性铰链位移精度的有限元分析%Finite Element Analysis of Displacement Accuracy of Single-notch Right Circular Flexure Hinge

    Institute of Scientific and Technical Information of China (English)

    沈剑英; 李积武; 赵云

    2011-01-01

    提出了单边直圆型柔性铰链的位移精度系数和偏移率概念,为了分析柔性铰链的结构参数与位移精度系数和偏移率之间的关系,利用ANSYS软件提供的参数化程序设计语言APDL编制程序,实现快速、方便地自动生成柔性铰链的参数化有限元分析模型.分析结果表明:随着最小厚度的增大,位移精度系数减小,而偏移率就增大;切割半径增大,位移精度系数增大,则偏移率减小,而宽度的变化对位移精度系数和偏移率影响很小.%The displacement accuracy coefficient and the offset rate of flexure hinge are put forward in the paper. A fast and easy parametric finite element analytic method based on APDL language in ANSYS is employed to study the relationship between the basic construction parameters of flexure hinge and the two coefficients. The analytic results demonstrate that the displacement accuracy coefficient is reduced as the minimum thickness increases while the offset rate is increased, and that the displacement accuracy coefficient is increased as the cutting radius increases while the offset rate is reduced. It also shows the variation of the width of flexure hinge has little influence on the displacement accuracy coefficient and the offset rate.

  11. Accuracy Analysis of ICESat Laser Altimeter Data Using TOPEX Data%卫星激光测高ICESat确定海面高精度分析

    Institute of Scientific and Technical Information of China (English)

    聂琳娟; 范春波; 超能芳

    2011-01-01

    讨论了ICESat卫星在大地测量学与海洋学中的应用,利用目前国际上公认的最高精度的测高数据TOPEX,分析了ICESat确定的海平面高以及中尺度的海面异常精度,给出了统计结果。%Application research on geodesy and oceanography of ICESat are discussed.We analyze the accuracy of ICESat data using TOPEX data as well as the statistic of the mean and standard deviation between them.A systematic deviation of 10 cm is foud.

  12. Increased productivity of repair verification by offline analysis of aerial images

    Science.gov (United States)

    Villa, Ernesto; Sartelli, Luca; Miyashita, Hiroyuki; Scheruebl, Thomas; Richter, Rigo; Thaler, Thomas

    2010-05-01

    Using AIMSTM to qualify repairs of defects on photomasks is the industry standard. AIMSTM provides a reasonable matching of lithographic imaging performances without the need of wafer prints. The need of utilisation of this capability by photomask manufacturers has risen due to the increased complexity of layouts incorporating aggressive RET and phase shift technologies as well as tighter specifications have pushed aerial image metrology to consider CD performance results in addition to the traditional intensity verification. The content of the paper describes the utilisation of the AIMSTM Repair Verification (RV) software for the verification of aerial images in a mask shop production environment. The software is used to analyze images from various AIMSTM tool generations and the two main routines, Multi Slice Analysis (MSA) and Image Compare (IC), are used to compare defective and non-defective areas of aerial images. It is detailed how the RV software cleans "non real" errors potentially induced by operator misjudgements, thus providing accurate and repeatable analyses all proven against the results achieved manually. A user friendly GUI drives the user through few simple, fast and safe operations and automatically provides summary tables containing all the relevant results of the analysis that can be easily exported in a proper format and sent out to the customer as a technical documentation. This results in a sensible improvement of the throughput of the printability evaluation process in a mask manufacturing environment, providing reliable analyses at a higher productivity.

  13. Whole transcriptome analysis of transgenic barley with altered cytokinin homeostasis and increased tolerance to drought stress.

    Science.gov (United States)

    Vojta, Petr; Kokáš, Filip; Husičková, Alexandra; Grúz, Jiří; Bergougnoux, Veronique; Marchetti, Cintia F; Jiskrová, Eva; Ježilová, Eliška; Mik, Václav; Ikeda, Yoshihisa; Galuszka, Petr

    2016-09-25

    Cytokinin plant hormones have been shown to play an important role in plant response to abiotic stresses. Herein, we expand upon the findings of Pospíšilová et al. [30] regarding preparation of novel transgenic barley lines overexpressing cytokinin dehydrogenase 1 gene from Arabidopsis under the control of mild root-specific promotor of maize β-glycosidase. These lines showed drought-tolerant phenotype mainly due to alteration of root architecture and stronger lignification of root tissue. A detailed transcriptomic analysis of roots of transgenic plants subjected to revitalization after drought stress revealed attenuated response through the HvHK3 cytokinin receptor and up-regulation of two transcription factors implicated in stress responses and abscisic acid sensitivity. Increased expression of several genes involved in the phenylpropanoid pathway as well as of genes encoding arogenate dehydratase/lyase participating in phenylalanine synthesis was found in roots during revitalization. Although more precursors of lignin synthesis were present in roots after drought stress, final lignin accumulation did not change compared to that in plants grown under optimal conditions. Changes in transcriptome indicated a higher auxin turnover in transgenic roots. The same analysis in leaves revealed that genes encoding putative enzymes responsible for production of jasmonates and other volatile compounds were up-regulated. Although transgenic barley leaves showed lower chlorophyll content and down-regulation of genes encoding proteins involved in photosynthesis than did wild-type plants when cultivated under optimal conditions, they did show a tendency to return to initial photochemical activities faster than did wild-type leaves when re-watered after severe drought stress. In contrast to optimal conditions, comparative transcriptomic analysis of revitalized leaves displayed up-regulation of genes encoding enzymes and proteins involved in photosynthesis, and especially

  14. Economic Analysis of Cikaso Mini Hydro Power Plant as a CDM Project for Increasing IRR

    Directory of Open Access Journals (Sweden)

    Irhan Febijanto

    2013-12-01

    Full Text Available Renewable energy fueled power generations are few developed by private sector in Indonesia. High-cost investment and low electricity selling price to PT PLN as a single buyer is main barriers for private sector to involve in the development of renewable energy fueled power generations. In this project, the economic feasibility of Mini Hydro Power Plant of Cikaso with capacity of 5.3 MW, located at Sukabumi Regency, West Java province was assessed. This project utilized revenue generated from carbon market to increase the economic feasibility. Procedure to register the project to United Nation for Climate Change Convention (UNFCCC as a Clean Development Mechanism project was explained in detail. Approved Consolidation Methodology (ACM 0002 Version 12.3.0 was used to calculate grid emission factor in Jawa-Bali-Madura the grid electricity system. It was calculated that the grid emission factor is 0.833 (t-CO2/MWh, and the carbon emission reduction generated for this project is 21,982 ton/year. From the analysis result, it can be proven that the additional revenue from carbon credit could increase the project IRR from 10.28% to 13.52%.

  15. Factor Analysis of Accuracy in Step Test%台阶试验准确度影响因素分析

    Institute of Scientific and Technical Information of China (English)

    谢晓斌

    2012-01-01

    研究目的:分析影响台阶试验准确度的因素。方法:采用实验法、统计法、比较法、文献法等。结果:影响台阶试验准确度的因素较多,如客观上仪器设备的稳定性和标准性,主观上测试要求和方法上的难于操作性。结论:台阶试验与中长跑项目的兼容性和作为体质健康评价标准必测项目需要进一步探讨。%Based on the experiment,statistics,comparison and literature review,this thesis aims to probe into the factors that have effects on the accuracy in step test.It is found that many factors contribute the accuracy of step test.Objective factors(the standard and stability of the equipments) and subjective factors(the difficult operation of test requirements and methods) are the major ones.It is concluded that further discussion is necessary about the compatibility between step test and middle-long distance running and the necessarily measured items for the evaluation standard of physical health.

  16. Modeling and accuracy analysis for multiple heads star tracker%多视场星敏感器数学模型与精度分析

    Institute of Scientific and Technical Information of China (English)

    李健; 张广军; 魏新国

    2015-01-01

    多视场星敏感器与传统单视场星敏感器相比不仅具有更高的可靠性和自主性,也具有更高的精度和动态性能,是未来星敏感器发展的重要趋势之一。为获得最佳性能,需要对多视场星敏感器的视场大小和布局进行优化。为此,首先建立了多视场星敏感器的数学模型,重点介绍了星点成像和姿态计算。然后推导了多视场星敏感器测量精度的数学表示,分析了影响精度的因素。通过仿真分析了多视场星敏感器视场大小和布局对各因素和精度的影响。仿真结果表明,视场大小对星敏感器精度的影响取决于星敏感器的运动情况,当角速度较小时,视场越小,精度越高;当角速度较大时,视场越大,精度越高。而各视轴相互正交的视场布局下,多视场星敏感器的测量精度最高。%As an important trend in the future, multiple heads star tracker is not only of higher reliability and autonomy, but also of higher precision and dynamic performance than classical star tracker. In order to achieve the best performance, system parameters optimization for multiple heads star tracker is needed. A mathematical model of multiple heads star tracker was developed firstly, particularly on the star imaging and attitude determination. Then an analytic expression of accuracy was deduced, and the error sources affecting the attitude accuracy were analyzed. Finally, the effects of the field of view and the relative alignment on the accuracy were discussed systematically based on the simulation results. The results show that the relation between field of view and accuracy depends on the angular rate. The accuracy is improved with smaller field of view at lower angular rate, while with larger field of view at higher angular rate. And multiple heads star sensor reaches the highest precision when the boresights are orthogonal.

  17. Reticence, Accuracy and Efficacy

    Science.gov (United States)

    Oreskes, N.; Lewandowsky, S.

    2015-12-01

    James Hansen has cautioned the scientific community against "reticence," by which he means a reluctance to speak in public about the threat of climate change. This may contribute to social inaction, with the result that society fails to respond appropriately to threats that are well understood scientifically. Against this, others have warned against the dangers of "crying wolf," suggesting that reticence protects scientific credibility. We argue that both these positions are missing an important point: that reticence is not only a matter of style but also of substance. In previous work, Bysse et al. (2013) showed that scientific projections of key indicators of climate change have been skewed towards the low end of actual events, suggesting a bias in scientific work. More recently, we have shown that scientific efforts to be responsive to contrarian challenges have led scientists to adopt the terminology of a "pause" or "hiatus" in climate warming, despite the lack of evidence to support such a conclusion (Lewandowsky et al., 2015a. 2015b). In the former case, scientific conservatism has led to under-estimation of climate related changes. In the latter case, the use of misleading terminology has perpetuated scientific misunderstanding and hindered effective communication. Scientific communication should embody two equally important goals: 1) accuracy in communicating scientific information and 2) efficacy in expressing what that information means. Scientists should strive to be neither conservative nor adventurous but to be accurate, and to communicate that accurate information effectively.

  18. Increase in dust storm related PM10 concentrations: A time series analysis of 2001-2015.

    Science.gov (United States)

    Krasnov, Helena; Katra, Itzhak; Friger, Michael

    2016-06-01

    Over the last decades, changes in dust storms characteristics have been observed in different parts of the world. The changing frequency of dust storms in the southeastern Mediterranean has led to growing concern regarding atmospheric PM10 levels. A classic time series additive model was used in order to describe and evaluate the changes in PM10 concentrations during dust storm days in different cities in Israel, which is located at the margins of the global dust belt. The analysis revealed variations in the number of dust events and PM10 concentrations during 2001-2015. A significant increase in PM10 concentrations was identified since 2009 in the arid city of Beer Sheva, southern Israel. Average PM10 concentrations during dust days before 2009 were 406, 312, and 364 μg m(-3) (median 337, 269,302) for Beer Sheva, Rehovot (central Israel) and Modi'in (eastern Israel), respectively. After 2009 the average concentrations in these cities during dust storms were 536, 466, and 428 μg m(-3) (median 382, 335, 338), respectively. Regression analysis revealed associations between PM10 variations and seasonality, wind speed, as well as relative humidity. The trends and periodicity are stronger in the southern part of Israel, where higher PM10 concentrations are found. Since 2009 dust events became more extreme with much higher daily and hourly levels. The findings demonstrate that in the arid area variations of dust storms can be quantified easier through PM10 levels over a relatively short time scale of several years. PMID:26874873

  19. The effect of sequential coupling on radial displacement accuracy in electromagnetic inside-bead forming: simulation and experimental analysis using Maxwell and ABAQUS software

    Energy Technology Data Exchange (ETDEWEB)

    Chaharmiri, Rasoul; Arezoodar, Alireza Fallahi [Amirkabir University, Tehran (Iran, Islamic Republic of)

    2016-05-15

    Electromagnetic forming (EMF) is a high strain rate forming technology which can effectively deform and shape high electrically conductive materials at room temperature. In this study, the electromagnetic and mechanical parts of the process simulated using Maxwell and ABAQUS software, respectively. To provide a link between the software, two approaches include 'loose' and 'sequential' coupling were applied. This paper is aimed to investigate how sequential coupling would affect radial displacement accuracy, as an indicator of tube final shape, at various discharge voltages. The results indicated a good agreement for the both approaches at lower discharge voltages with more accurate results for sequential coupling, but at high discharge voltages, there was a non-negligible overestimation of about 43% for the loose coupling reduced to only 8.2% difference by applying sequential coupling in the case studied. Therefore, in order to reach more accurate predictions, applying sequential coupling especially at higher discharge voltages is strongly recommended.

  20. THE ANALYSIS OF POPULATION MORBIDITY RATE DUE TO INCREASED ENERGY DEMAND

    Directory of Open Access Journals (Sweden)

    Perticas Diana

    2012-07-01

    Full Text Available Sustainable development as general acceptance is that form of ensuring the bio-socio-economic needs of the present generation without affecting the existence and development opportunities for the generations to come. Secondary, the concept refers to the protection of the environment that is at present greatly affected by externalities of the socio-economic activity of previous and present generations. As it is shown in this paper the negative effects of the environmental pollution records higher and higher values in a short period of time of which we analyze their impact on population health, focusing on the situation of Romania. I started the analysis from the assumptions that the health of an organism is a normal physical and physiological state, being the opposite of the concept disease. The most common diseases are: hereditary, infectious, internal, infantile, autoimmune, allergic, socio-professional, tumorous, degenerative diseases etc. Of these infant, allergic, tumorous and autoimmune diseases are mainly generated by environmental pollution. Extremely special, regarding the incidence of harmful environmental factors, are the socio-professional diseases or of civilization that are represented by those diseases that are more common in industrialized countries than in the so called third world. In respect to air pollution-generated illnesses with products resulting from burning fossil fuels are highlighted respiratory diseases, immunological diseases, benign and malignant neoplasm of the airways and also dermatitis. Most activities follow sooner or later to increase welfare. Economic growth, environmental protection as well as fulfilling social needs of individuals are only a few elements that lead to the increase of population welfare. If we accept the above mentioned things, then it means that promoting the realisation of sustainable development based on clean and renewable resources and the rationally using the conventional ones is an

  1. How can self-efficacy be increased? Meta-analysis of dietary interventions.

    Science.gov (United States)

    Prestwich, Andrew; Kellar, Ian; Parker, Richard; MacRae, Siobhan; Learmonth, Matthew; Sykes, Bianca; Taylor, Natalie; Castle, Holly

    2014-01-01

    Targeting individuals' beliefs that they are able to eat healthily can improve dietary-related behaviours. However, the most effective behaviour change techniques (BCTs) to promote dietary self-efficacy have not been systematically reviewed. This research addressed this gap. Studies testing the effect of interventions on healthy eating and underlying dietary-related self-efficacy, within randomised controlled trials, were systematically reviewed in MEDLINE, EMBASE and PSYCINFO. Two reviewers independently coded intervention content in both intervention and comparison groups. Data pertaining to study quality were also extracted. Random effects meta-analysis was used to calculate an overall effect size on dietary self-efficacy for each study. The associations between 26 BCTs and self-efficacy effects were calculated using meta-regression. In some of the analyses, interventions that incorporated self-monitoring (tracking one's own food-related behaviour), provided feedback on performance, prompted review of behavioural goals, provided contingent rewards (rewarding diet success), or planned for social support/social change increased dietary self-efficacy significantly more than interventions that did not. Stress management was consistently associated with self-efficacy effects across all analyses. There was strong evidence for stress management and weaker evidence for a number of other BCTs. The findings can be used to develop more effective, theory- and evidence-based behavioural interventions.

  2. How can self-efficacy be increased? Meta-analysis of dietary interventions.

    Science.gov (United States)

    Prestwich, Andrew; Kellar, Ian; Parker, Richard; MacRae, Siobhan; Learmonth, Matthew; Sykes, Bianca; Taylor, Natalie; Castle, Holly

    2014-01-01

    Targeting individuals' beliefs that they are able to eat healthily can improve dietary-related behaviours. However, the most effective behaviour change techniques (BCTs) to promote dietary self-efficacy have not been systematically reviewed. This research addressed this gap. Studies testing the effect of interventions on healthy eating and underlying dietary-related self-efficacy, within randomised controlled trials, were systematically reviewed in MEDLINE, EMBASE and PSYCINFO. Two reviewers independently coded intervention content in both intervention and comparison groups. Data pertaining to study quality were also extracted. Random effects meta-analysis was used to calculate an overall effect size on dietary self-efficacy for each study. The associations between 26 BCTs and self-efficacy effects were calculated using meta-regression. In some of the analyses, interventions that incorporated self-monitoring (tracking one's own food-related behaviour), provided feedback on performance, prompted review of behavioural goals, provided contingent rewards (rewarding diet success), or planned for social support/social change increased dietary self-efficacy significantly more than interventions that did not. Stress management was consistently associated with self-efficacy effects across all analyses. There was strong evidence for stress management and weaker evidence for a number of other BCTs. The findings can be used to develop more effective, theory- and evidence-based behavioural interventions. PMID:25053214

  3. Metabolic Syndrome Is Associated with Increased Breast Cancer Risk: A Systematic Review with Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Ruchi Bhandari

    2014-01-01

    Full Text Available Background. Although individual metabolic risk factors are reported to be associated with breast cancer risk, controversy surrounds risk of breast cancer from metabolic syndrome (MS. We report the first systematic review and meta-analysis of the association between MS and breast cancer risk in all adult females. Methods. Studies were retrieved by searching four electronic reference databases [PubMed, Cumulative Index to Nursing and Allied Health Literature (CINAHL, Web of Science, and ProQuest through June 30, 2012] and cross-referencing retrieved articles. Eligible for inclusion were longitudinal studies reporting associations between MS and breast cancer risk among females aged 18 years and older. Relative risks and 95% confidence intervals were calculated for each study and pooled using random-effects models. Publication bias was assessed quantitatively (Trim and Fill and qualitatively (funnel plots. Heterogeneity was examined using Q and I2 statistics. Results. Representing nine independent cohorts and 97,277 adult females, eight studies met the inclusion criteria. A modest, positive association was observed between MS and breast cancer risk (RR: 1.47, 95% CI, 1.15–1.87; z=3.13; p=0.002; Q=26.28, p=0.001; I2=69.55%. No publication bias was observed. Conclusions. MS is associated with increased breast cancer risk in adult women.

  4. Mathematical Analysis of Space Radiator Segmenting for Increased Reliability and Reduced Mass

    Science.gov (United States)

    Juhasz, Albert J.

    2001-01-01

    Spacecraft for long duration deep space missions will need to be designed to survive micrometeoroid bombardment of their surfaces some of which may actually be punctured. To avoid loss of the entire mission the damage due to such punctures must be limited to small, localized areas. This is especially true for power system radiators, which necessarily feature large surface areas to reject heat at relatively low temperature to the space environment by thermal radiation. It may be intuitively obvious that if a space radiator is composed of a large number of independently operating segments, such as heat pipes, a random micrometeoroid puncture will result only in the loss of the punctured segment, and not the entire radiator. Due to the redundancy achieved by independently operating segments, the wall thickness and consequently the weight of such segments can be drastically reduced. Probability theory is used to estimate the magnitude of such weight reductions as the number of segments is increased. An analysis of relevant parameter values required for minimum mass segmented radiators is also included.

  5. Increased accuracy in heparin and protamine administration decreases bleeding

    DEFF Research Database (Denmark)

    Runge, Marx; Møller, Christian H; Steinbrüchel, Daniel A

    2009-01-01

    Three to 5 percent of the patients undergoing cardiac surgery are reoperated because of bleeding. When a surgical cause can be excluded, heparin/protamine mismatch may be considered. Insufficient reversal of heparin and overdosing of protamine may cause postoperative bleeding. The purpose...... of the study was to evaluate whether a heparin-protamine titration system, Hemochron RxDx, could reduce postoperative bleeding and blood transfusion. Fifty-three patients were included prospectively over a 6-month period. The test group (RxDx group; 28 patients) received heparin and protamine doses calculated...... using the Hemochron RxDx system, which performs a baseline activated clotting time (ACT) value together with a heparin response test. An accurate heparin dose was calculated based on the Bull dose/response curve. Protamine doses were calculated by the same method. In the control group (25 patients...

  6. MPR realignment increases accuracy when measuring femoral neck anteversion angle

    DEFF Research Database (Denmark)

    Olesen, Tommy Hemmert; Torfing, Trine; Overgaard, Søren

    2013-01-01

    To compare two methods of measuring femoral neck anteversion angle (FNA): A 2D method used at Odense University Hospital until 2010, and a method labeled 3D-OUH. The latter method makes corrections to compensate for errors introduced by the individual placement of patients in the CT scanner....

  7. Increasing Selection Accuracy and Speed through Progressive Refinement

    OpenAIRE

    Bacim de Araujo e Silva, Felipe

    2015-01-01

    Although many selection techniques have been proposed and developed over the years, selection by pointing is perhaps the most popular approach for selection. In 3D interfaces, the laser-pointer metaphor is commonly used, since users only have to point to their target from a distance. However, the task of selecting objects that have a small visible area or that are in highly cluttered environments is hard when using pointing techniques. With both indirect and direct pointing techniques in 3D i...

  8. Cooperation between Referees and Authors Increases Peer Review Accuracy

    OpenAIRE

    Leek, Jeffrey T.; Taub, Margaret A; Pineda, Fernando J.

    2011-01-01

    Peer review is fundamentally a cooperative process between scientists in a community who agree to review each other's work in an unbiased fashion. Peer review is the foundation for decisions concerning publication in journals, awarding of grants, and academic promotion. Here we perform a laboratory study of open and closed peer review based on an online game. We show that when reviewer behavior was made public under open review, reviewers were rewarded for refereeing and formed significantly ...

  9. Accuracy of Reconstruction of the Tree Stem Surface Using Terrestrial Close-Range Photogrammetry

    Directory of Open Access Journals (Sweden)

    Peter Surový

    2016-02-01

    Full Text Available Airborne laser scanning (ALS allows for extensive coverage, but the accuracy of tree detection and form can be limited. Although terrestrial laser scanning (TLS can improve on ALS accuracy, it is rather expensive and area coverage is limited. Multi-view stereopsis (MVS techniques combining computer vision and photogrammetry may offer some of the coverage benefits of ALS and the improved accuracy of TLS; MVS combines computer vision research and automatic analysis of digital images from common commercial digital cameras with various algorithms to reconstruct three-dimensional (3D objects with realistic shape and appearance. Despite the relative accuracy (relative geometrical distortion of the reconstructions available in the processing software, the absolute accuracy is uncertain and difficult to evaluate. We evaluated the data collected by a common digital camera through the processing software (Agisoft PhotoScan © for photogrammetry by comparing those by direct measurement of the 3D magnetic motion tracker. Our analyses indicated that the error is mostly concentrated in the portions of the tree where visibility is lower, i.e., the bottom and upper parts of the stem. For each reference point from the digitizer we determined how many cameras could view this point. With a greater number of cameras we found increasing accuracy of the measured object space point positions (as expected, with a significant positive change in the trend beyond five cameras; when more than five cameras could view this point, the accuracy began to increase more abruptly, but eight cameras or more provided no increases in accuracy. This method allows for the retrieval of larger datasets from the measurements, which could improve the accuracy of estimates of 3D structure of trees at potentially reduced costs.

  10. Analysis of Firing Accuracy for Terminal Sensing Ammunition of Guided Rokect%制导火箭末敏弹射击精度分析

    Institute of Scientific and Technical Information of China (English)

    翟英存; 陈德明

    2015-01-01

    制导火箭末敏弹是火箭制导控制技术和末敏弹技术有机结合的新型弹药,针对此前制导火箭与末敏子弹相结合的系统射击精度研究不够充分的问题,根据制导火箭末敏弹的工作流程和弹道特点,建立了各飞行段制导火箭和末敏子弹的弹道模型,通过分析各弹道段扰动因素的影响,对误差源进行了分配,运用 Monte-Carlo 法进行了射击精度仿真计算和分析。结果表明,制导火箭末敏弹系统射击精度(CEP)不大于60 m,与末敏子弹的扫描探测范围匹配,满足精确打击小幅员目标的要求。分析方法和仿真结果对完善制导火箭末敏弹指标体系、优化弹道方案以及作战使用时计算用弹量等具有重要意义,也可作为同类装备设计参考。%The guided rocket with terminal sensing ammunition is a newly developed ammunition, and the technology of rocket guidance and controlling is integrated with terminal sensing ammunition.The firing accuracy of integrated system of the guided rocket and terminal sensing submunition is poorly studied.Aiming at this problem,the trajectory model was built for guided rocket and terminal sensing ammunition’s submunition in different flight profile according to op-erational procedure and ballistic features of guided rocket terminal-sensing-ammunition.The influence of disturbing factors in different flight profile was analyzed,and the error source was al-located.The firing accuracy was simulated and analyzed by Monte-Carle method.The results show that the firing accuracy(CEP)of guided rocket with terminal submunition is not more than 60 m,which matches with the detection boundary of terminal sensing submunition,and it satisfies the requirement of attacking the small group targets.The analyzing methods and calculated results are very important for perfecting the index system of guided rocket terminal-sensing-sub-munition,optimization of the trajectory scheme as well as calculating the

  11. Accuracy Analysis and Evaluation of InSAR Land Subsidence Monitoring%InSAR 地面沉降监测精度分析与评价

    Institute of Scientific and Technical Information of China (English)

    汪宝存; 远顺立; 王继华; 郭凌飞; 王文杰; 焦学军

    2015-01-01

    针对 InSAR 地面沉降监测精度所受到的质疑,以郑州市为研究区,该文提出了在 SAR 卫星过境获取图像的同时开展水准测量,通过开展地面沉降星地同步观测实验,即利用水准观测结果对 InSAR 地面沉降监测的精度进行了对比分析与评价。分别于2012年11月、2013年6月、8月,开展了3次同步观测实验,获取了 InSAR与同步的水准监测数据,通过统一参考基准,纠正了 InSAR、水准两种测量方法测量结果出现的整体偏差;统一参考基准后,最临近距离的平均误差在±1.9mm~4.8mm 之间,中误差在±2.3mm~5.6mm 之间,采用克里金插值法的平均误差在±1.5mm~3.8mm 之间,中误差在±1.9mm~4.6mm 之间。结果表明 InSAR 地面沉降监测具有较高的测量精度。%This paper takes Zhengzhou city as the research area,aiming at the question of InSAR land subsidence monitoring accuracy,then carries out the “land subsidence observation experiment by synchronize satellite and ground”with the way of levelling when SAR satellite captures images.Namely,we analyze and evaluate the InSAR land subsidence monitoring accuracy by utilizing the levelling results.Three synchronize experiments were carried out in August 2012,November 2013 and June 2013,then InSAR and synchronize levelling results were acquired.The whole deviation of InSAR and levelling measurement results were corrected through the unified reference.The average error of the near distance between ±1.9mm~4.8mm and the mean square error between ±2.3mm~5.6mm after the reference been unified.The average error between ±1.5mm~3.8mm and the mean square error between ±1.9mm~4.6mm after applying the kriging interpolation method.Results showed that the InSAR land subsidence monitoring have higher measuring accuracy.

  12. A quest to increase safety of anesthetics by advancements in anesthesia monitoring: scientometric analysis

    Directory of Open Access Journals (Sweden)

    Vlassakov KV

    2015-05-01

    Full Text Available Kamen V Vlassakov, Igor Kissin Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA Abstract: The aim of this study was to assess progress in the field of anesthesia monitoring over the past 40 years using scientometric analysis. The following scientometric indexes were used: popularity indexes (general and specific, representing the proportion of articles on either a topic relative to all articles in the field of anesthetics (general popularity index, GPI or the subfield of anesthesia monitoring (specific popularity index, SPI; index of change (IC, representing the degree of growth in publications on a topic from one period to the next; and index of expectations (IE, representing the ratio of the number of articles on a topic in the top 20 journals relative to the number of articles in all (>5,000 biomedical journals covered by PubMed. Publications on 33 anesthesia-monitoring topics were assessed. Our analysis showed that over the past 40 years, the rate of rise in the number of articles on anesthesia monitoring was exponential, with an increase of more than eleven-fold, from 296 articles over the 5-year period 1974–1978 to 3,394 articles for 2009–2013. This rise profoundly exceeded the rate of rise of the number