WorldWideScience

Sample records for methodology accuracy precision

  1. Availability of Po-210 present in phosphogypsum used in agriculture: precision and accuracy of the methodology

    Energy Technology Data Exchange (ETDEWEB)

    Groppo, Guilherme H.; Mazzilli, Barbara P.; Saueia, Catia H.R., E-mail: g.groppo@ipen.br, E-mail: mazzilli@ipen.br, E-mail: chsaueia@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Phosphogypsum (PG) is a NORM residue of the phosphate fertilizer industry, and is stored in stacks at a rate of 5.5 x 10{sup 6} tons annually. In Brazil, PG has been used for many years as a soil conditioner. The Brazilian regulatory agency has established a limit of 1000 Bq kg{sup -1} for Ra-226 and Ra-228 and below this limit its use in agriculture is exempted of regulatory control. This study aims to determine the availability of the radionuclide Po-210 in the use of PG in agriculture as a soil conditioner. The Po-210 was purified and concentrated using a Sr-Spec resin. The final activity concentration was determined by spontaneous deposition of Po-210 in a silver disk and measurement by alpha spectrometry. The accuracy and precision of the methodology was checked by using a standard reference material provided by International Atomic Energy Agency, IAEA 385 - Irish Sea Sediment, and a Po-210 standard solution provided by Instituto de Radioprotecao e Dosimetria (IRD), Rio de Janeiro, RJ. The precision and accuracy achieved varied from 2.2% to 7.6% and from 1.5% to 17.5%, respectively. (author)

  2. Availability of Po-210 present in phosphogypsum used in agriculture: precision and accuracy of the methodology

    International Nuclear Information System (INIS)

    Groppo, Guilherme H.; Mazzilli, Barbara P.; Saueia, Catia H.R.

    2013-01-01

    Phosphogypsum (PG) is a NORM residue of the phosphate fertilizer industry, and is stored in stacks at a rate of 5.5 x 10 6 tons annually. In Brazil, PG has been used for many years as a soil conditioner. The Brazilian regulatory agency has established a limit of 1000 Bq kg -1 for Ra-226 and Ra-228 and below this limit its use in agriculture is exempted of regulatory control. This study aims to determine the availability of the radionuclide Po-210 in the use of PG in agriculture as a soil conditioner. The Po-210 was purified and concentrated using a Sr-Spec resin. The final activity concentration was determined by spontaneous deposition of Po-210 in a silver disk and measurement by alpha spectrometry. The accuracy and precision of the methodology was checked by using a standard reference material provided by International Atomic Energy Agency, IAEA 385 - Irish Sea Sediment, and a Po-210 standard solution provided by Instituto de Radioprotecao e Dosimetria (IRD), Rio de Janeiro, RJ. The precision and accuracy achieved varied from 2.2% to 7.6% and from 1.5% to 17.5%, respectively. (author)

  3. Methodologies for the measurement of bone density and their precision and accuracy

    International Nuclear Information System (INIS)

    Goodwin, P.N.

    1987-01-01

    Radiographic methods of determining bone density have been available for many years, but recently most of the efforts in this field have focused on the development of instruments which would accurately and automatically measure bone density by absorption, or by the use of x-ray computed tomography (CT). Single energy absorptiometers using I-125 have been available for some years, and have been used primarily for measurements on the radius, although recently equipment for measuring the os calcis has become available. Accuracy of single energy measurements is about 3% to 5%; precision, which has been poor because of the difficulty of exact repositioning, has recently been improved by automatic methods so that it now approaches 1% or better. Dual energy sources offer the advantages of greater accuracy and the ability to measure the spine and other large bones. A number of dual energy scanners are now on the market, mostly using gadolinium-153 as a source. Dual energy scanning is capable of an accuracy of a few percent, but the precision when scanning patients can vary widely, due to the difficulty of comparing exactly the same areas; 2 to 4% would appear to be typical. Quantitative computed tomography (QCT) can be used to directly measure the trabecular bone within the vertebral body. The accuracy of single-energy QCT is affected by the amount of marrow fat present, which can lead to underestimations of 10% or more. An increase in marrow fat would cause an apparent decrease in bone mineral. However, the precision can be quite good, 1% or 2% on phantoms, and nearly as good on patients when four vertebrae are averaged. Dual energy scanning can correct for the presence of fat, but is less precise, and not available on all CT units. 52 references

  4. Availability of U-238 and Th-232 present in phosphogypsum used in agriculture: precision and accuracy of the methodology

    International Nuclear Information System (INIS)

    Malheiro, Luciano H.; Saueia, Catia H.R.; Mazzilli, Barbara P.

    2013-01-01

    Phosphogypsum (PG) can be classified as Technologically Enhanced Naturally Occurring Radioactive Material (TENORM), and it is obtained as a residue of the phosphate fertilizer industry. PG presents in its composition radionuclides of the natural U and Th series: mainly Ra-226, Ra-228, Th-232, Pb-210 and Po-210. The Brazilian producers stock the PG in dry stacks, posing risks to the surrounding environment. A possible solution to this problem is to reuse PG in agriculture; however, it is necessary to ensure that the radionuclides present in the PG will not be available to the agricultural products. This study is part of a research project sponsored by Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP - 2010-10587-0) entitled 'Availability of metals and radionuclides in tropical soils amended with phosphogypsum', and its objective is to evaluate the reliability of an optimal methodology to determine U-238 and Th-232 in samples of soils amended with PG through percolation with water. The methodology comprises a sequential radiochemical separation of the radionuclides present in the leachate. The UTEVA resin was used for the purification and separation of U-238 and Th-232, and the final activity concentrations were determined by alpha spectrometry. The precision and accuracy of the methodology were checked by measuring standard reference material. The results obtained for the relative error and relative standard deviation varied respectively from 2.34 % to 5.92 % and 6.10 % to 6.21 % for uranium, and from 0.42 % to 3.13 % and 9.68 % to 10.97 % for thorium. (author)

  5. Precision and accuracy in radiotherapy

    International Nuclear Information System (INIS)

    Brenner, J.D.

    1989-01-01

    The required precision due to random errors in the delivery of fractionated dose regime is considered. It is argued that suggestions that 1-3% precision is needed may be unnecessarily conservative. It is further suggested that random and systematic errors should not be combined with equal weight to yield an overall target uncertainty in dose delivery, systematic errors being of greater significance. The authors conclude that imprecise dose delivery and inaccurate dose delivery affect patient-cure results differently. Whereas, for example, a 10% inaccuracy in dose delivery would be quite catastrophic in the case considered here, a corresponding imprecision would have a much smaller effect on overall success rates. (author). 14 refs.; 2 figs

  6. Accuracy and precision in thermoluminescence dosimetry

    International Nuclear Information System (INIS)

    Marshall, T.O.

    1984-01-01

    The question of accuracy and precision in thermoluminescent dosimetry, particularly in relation to lithium fluoride phosphor, is discussed. The more important sources of error, including those due to the detectors, the reader, annealing and dosemeter design, are identified and methods of reducing their effects on accuracy and precision to a minimum are given. Finally, the accuracy and precision achievable for three quite different applications are discussed, namely, for personal dosimetry, environmental monitoring and for the measurement of photon dose distributions in phantoms. (U.K.)

  7. A Note on "Accuracy" and "Precision"

    Science.gov (United States)

    Stallings, William M.; Gillmore, Gerald M.

    1971-01-01

    Advocates the use of precision" rather than accuracy" in defining reliability. These terms are consistently differentiated in certain sciences. Review of psychological and measurement literature reveals, however, interchangeable usage of the terms in defining reliability. (Author/GS)

  8. Accuracy and precision in activation analysis: counting

    International Nuclear Information System (INIS)

    Becker, D.A.

    1974-01-01

    Accuracy and precision in activation analysis was investigated with regard to counting of induced radioactivity. The various parameters discussed include configuration, positioning, density, homogeneity, intensity, radioisotopic purity, peak integration, and nuclear constants. Experimental results are presented for many of these parameters. The results obtained indicate that counting errors often contribute significantly to the inaccuracy and imprecision of analyses. The magnitude of these errors range from less than 1 percent to 10 percent or more in many cases

  9. Ultra-wideband ranging precision and accuracy

    International Nuclear Information System (INIS)

    MacGougan, Glenn; O'Keefe, Kyle; Klukas, Richard

    2009-01-01

    This paper provides an overview of ultra-wideband (UWB) in the context of ranging applications and assesses the precision and accuracy of UWB ranging from both a theoretical perspective and a practical perspective using real data. The paper begins with a brief history of UWB technology and the most current definition of what constitutes an UWB signal. The potential precision of UWB ranging is assessed using Cramer–Rao lower bound analysis. UWB ranging methods are described and potential error sources are discussed. Two types of commercially available UWB ranging radios are introduced which are used in testing. Actual ranging accuracy is assessed from line-of-sight testing under benign signal conditions by comparison to high-accuracy electronic distance measurements and to ranges derived from GPS real-time kinematic positioning. Range measurements obtained in outdoor testing with line-of-sight obstructions and strong reflection sources are compared to ranges derived from classically surveyed positions. The paper concludes with a discussion of the potential applications for UWB ranging

  10. Assessment of Sr-90 in water samples: precision and accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Nisti, Marcelo B.; Saueia, Cátia H.R.; Castilho, Bruna; Mazzilli, Barbara P., E-mail: mbnisti@ipen.br, E-mail: chsaueia@ipen.br, E-mail: bcastilho@ipen.br, E-mail: mazzilli@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2017-11-01

    The study of artificial radionuclides dispersion into the environment is very important to control the nuclear waste discharges, nuclear accidents and nuclear weapons testing. The accidents in Fukushima Daiichi Nuclear Power Plant and Chernobyl Nuclear Power Plant, released several radionuclides in the environment by aerial deposition and liquid discharge, with various level of radioactivity. The {sup 90}Sr was one of the elements released into the environment. The {sup 90}Sr is produced by nuclear fission with a physical half-life of 28.79 years with decay energy of 0.546 MeV. The aims of this study are to evaluate the precision and accuracy of three methodologies for the determination of {sup 90}Sr in water samples: Cerenkov, LSC direct method and with radiochemical separation. The performance of the methodologies was evaluated by using two scintillation counters (Quantulus and Hidex). The parameters Minimum Detectable Activity (MDA) and Figure Of Merit (FOM) were determined for each method, the precision and accuracy were checked using {sup 90}Sr standard solutions. (author)

  11. Assessment of Sr-90 in water samples: precision and accuracy

    International Nuclear Information System (INIS)

    Nisti, Marcelo B.; Saueia, Cátia H.R.; Castilho, Bruna; Mazzilli, Barbara P.

    2017-01-01

    The study of artificial radionuclides dispersion into the environment is very important to control the nuclear waste discharges, nuclear accidents and nuclear weapons testing. The accidents in Fukushima Daiichi Nuclear Power Plant and Chernobyl Nuclear Power Plant, released several radionuclides in the environment by aerial deposition and liquid discharge, with various level of radioactivity. The 90 Sr was one of the elements released into the environment. The 90 Sr is produced by nuclear fission with a physical half-life of 28.79 years with decay energy of 0.546 MeV. The aims of this study are to evaluate the precision and accuracy of three methodologies for the determination of 90 Sr in water samples: Cerenkov, LSC direct method and with radiochemical separation. The performance of the methodologies was evaluated by using two scintillation counters (Quantulus and Hidex). The parameters Minimum Detectable Activity (MDA) and Figure Of Merit (FOM) were determined for each method, the precision and accuracy were checked using 90 Sr standard solutions. (author)

  12. Precision and Accuracy in PDV and VISAR

    Energy Technology Data Exchange (ETDEWEB)

    Ambrose, W. P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-08-22

    This is a technical report discussing our current level of understanding of a wide and varying distribution of uncertainties in velocity results from Photonic Doppler Velocimetry in its application to gas gun experiments. Using propagation of errors methods with statistical averaging of photon number fluctuation in the detected photocurrent and subsequent addition of electronic recording noise, we learn that the velocity uncertainty in VISAR can be written in closed form. For PDV, the non-linear frequency transform and peak fitting methods employed make propagation of errors estimates notoriously more difficult to write down in closed form expect in the limit of constant velocity and low time resolution (large analysis-window width). An alternative method of error propagation in PDV is to use Monte Carlo methods with a simulation of the time domain signal based on results from the spectral domain. A key problem for Monte Carlo estimation for an experiment is a correct estimate of that portion of the time-domain noise associated with the peak-fitting region-of-interesting in the spectral domain. Using short-time Fourier transformation spectral analysis and working with the phase dependent real and imaginary parts allows removal of amplitude-noise cross terms that invariably show up when working with correlation-based methods or FFT power spectra. Estimation of the noise associated with a given spectral region of interest is then possible. At this level of progress, we learn that Monte Carlo trials with random recording noise and initial (uncontrolled) phase yields velocity uncertainties that are not as large as those observed. In a search for additional noise sources, a speckleinterference modulation contribution with off axis rays was investigated, and was found to add a velocity variation beyond that from the recording noise (due to random interference between off axis rays), but in our experiments the speckle modulation precision was not as important as the

  13. Hardware accuracy counters for application precision and quality feedback

    Science.gov (United States)

    de Paula Rosa Piga, Leonardo; Majumdar, Abhinandan; Paul, Indrani; Huang, Wei; Arora, Manish; Greathouse, Joseph L.

    2018-06-05

    Methods, devices, and systems for capturing an accuracy of an instruction executing on a processor. An instruction may be executed on the processor, and the accuracy of the instruction may be captured using a hardware counter circuit. The accuracy of the instruction may be captured by analyzing bits of at least one value of the instruction to determine a minimum or maximum precision datatype for representing the field, and determining whether to adjust a value of the hardware counter circuit accordingly. The representation may be output to a debugger or logfile for use by a developer, or may be output to a runtime or virtual machine to automatically adjust instruction precision or gating of portions of the processor datapath.

  14. Accuracy and precision of 3 intraoral scanners and accuracy of conventional impressions: A novel in vivo analysis method.

    Science.gov (United States)

    Nedelcu, R; Olsson, P; Nyström, I; Rydén, J; Thor, A

    2018-02-01

    To evaluate a novel methodology using industrial scanners as a reference, and assess in vivo accuracy of 3 intraoral scanners (IOS) and conventional impressions. Further, to evaluate IOS precision in vivo. Four reference-bodies were bonded to the buccal surfaces of upper premolars and incisors in five subjects. After three reference-scans, ATOS Core 80 (ATOS), subjects were scanned three times with three IOS systems: 3M True Definition (3M), CEREC Omnicam (OMNI) and Trios 3 (TRIOS). One conventional impression (IMPR) was taken, 3M Impregum Penta Soft, and poured models were digitized with laboratory scanner 3shape D1000 (D1000). Best-fit alignment of reference-bodies and 3D Compare Analysis was performed. Precision of ATOS and D1000 was assessed for quantitative evaluation and comparison. Accuracy of IOS and IMPR were analyzed using ATOS as reference. Precision of IOS was evaluated through intra-system comparison. Precision of ATOS reference scanner (mean 0.6 μm) and D1000 (mean 0.5 μm) was high. Pairwise multiple comparisons of reference-bodies located in different tooth positions displayed a statistically significant difference of accuracy between two scanner-groups: 3M and TRIOS, over OMNI (p value range 0.0001 to 0.0006). IMPR did not show any statistically significant difference to IOS. However, deviations of IOS and IMPR were within a similar magnitude. No statistical difference was found for IOS precision. The methodology can be used for assessing accuracy of IOS and IMPR in vivo in up to five units bilaterally from midline. 3M and TRIOS had a higher accuracy than OMNI. IMPR overlapped both groups. Intraoral scanners can be used as a replacement for conventional impressions when restoring up to ten units without extended edentulous spans. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  15. Accuracy, precision, and lower detection limits (a deficit reduction approach)

    International Nuclear Information System (INIS)

    Bishop, C.T.

    1993-01-01

    The evaluation of the accuracy, precision and lower detection limits of the determination of trace radionuclides in environmental samples can become quite sophisticated and time consuming. This in turn could add significant cost to the analyses being performed. In the present method, a open-quotes deficit reduction approachclose quotes has been taken to keep costs low, but at the same time provide defensible data. In order to measure the accuracy of a particular method, reference samples are measured over the time period that the actual samples are being analyzed. Using a Lotus spreadsheet, data are compiled and an average accuracy is computed. If pairs of reference samples are analyzed, then precision can also be evaluated from the duplicate data sets. The standard deviation can be calculated if the reference concentrations of the duplicates are all in the same general range. Laboratory blanks are used to estimate the lower detection limits. The lower detection limit is calculated as 4.65 times the standard deviation of a set of blank determinations made over a given period of time. A Lotus spreadsheet is again used to compile data and LDLs over different periods of time can be compared

  16. Precision and accuracy of β gauge for aerosol mass determinations

    International Nuclear Information System (INIS)

    Courtney, W.J.; Shaw, R.W.; Dzabay, T.G.

    1982-01-01

    Results of an experimental determination of the precision and the accuracy of a β-ray attenuation method for measurement of aerosol mass are presented. The instrumental precision for a short-term experiment was 25 μg for a 6.5-cm 2 deposit collected on approximately 1 mg/cm 2 Teflon filters; for a longer-term experiment the precision was 27 μg. The precision of the gravimetric determinations of aerosol deposits was 22 μg for Teflon filters weighed to 1 μg. Filter reorientation and air density changes that were able adversely to affect the β-ray attenuation results are discussed. β-ray attenuation results are in good agreement with gravimetric measurements on the same filter-collected aerosols. Using dichotomous samplers in Durham, NC, we collected 136 aerosol samples on Teflon filters in two size ranges. A regression line was calculated implicitly assuming errors in both measurements of mass. The 90% confidence intervals lay within 21 μg of the regression line for mean fine fraction aerosol mass loadings of 536 μg and within 19 μg of the regression line for mean coarse fraction aerosol mass loadings of 349 μg. Any bias between gravimetric and β-gauge mass measurements was found to be less than 5%

  17. Accuracy and precision in the calculation of phenology metrics

    DEFF Research Database (Denmark)

    Ferreira, Ana Sofia; Visser, Andre; MacKenzie, Brian

    2014-01-01

    a phenology metric is first determined from a noise- and gap-free time series, and again once it has been modified. We show that precision is a greater concern than accuracy for many of these metrics, an important point that has been hereto overlooked in the literature. The variability in precision between...... phenology metrics is substantial, but it can be improved by the use of preprocessing techniques (e.g., gap-filling or smoothing). Furthermore, there are important differences in the inherent variability of the metrics that may be crucial in the interpretation of studies based upon them. Of the considered......Phytoplankton phenology (the timing of seasonal events) is a commonly used indicator for evaluating responses of marine ecosystems to climate change. However, phenological metrics are vulnerable to observation-(bloom amplitude, missing data, and observational noise) and analysis-related (temporal...

  18. Precision and Accuracy Parameters in Structured Light 3-D Scanning

    Science.gov (United States)

    Eiríksson, E. R.; Wilm, J.; Pedersen, D. B.; Aanæs, H.

    2016-04-01

    Structured light systems are popular in part because they can be constructed from off-the-shelf low cost components. In this paper we quantitatively show how common design parameters affect precision and accuracy in such systems, supplying a much needed guide for practitioners. Our quantitative measure is the established VDI/VDE 2634 (Part 2) guideline using precision made calibration artifacts. Experiments are performed on our own structured light setup, consisting of two cameras and a projector. We place our focus on the influence of calibration design parameters, the calibration procedure and encoding strategy and present our findings. Finally, we compare our setup to a state of the art metrology grade commercial scanner. Our results show that comparable, and in some cases better, results can be obtained using the parameter settings determined in this study.

  19. Aspects of precision and accuracy in neutron activation analysis

    International Nuclear Information System (INIS)

    Heydorn, K.

    1980-03-01

    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

  20. Accuracy, precision, and economic efficiency for three methods of thrips (Thysanoptera: Thripidae) population density assessment.

    Science.gov (United States)

    Sutherland, Andrew M; Parrella, Michael P

    2011-08-01

    Western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), is a major horticultural pest and an important vector of plant viruses in many parts of the world. Methods for assessing thrips population density for pest management decision support are often inaccurate or imprecise due to thrips' positive thigmotaxis, small size, and naturally aggregated populations. Two established methods, flower tapping and an alcohol wash, were compared with a novel method, plant desiccation coupled with passive trapping, using accuracy, precision and economic efficiency as comparative variables. Observed accuracy was statistically similar and low (37.8-53.6%) for all three methods. Flower tapping was the least expensive method, in terms of person-hours, whereas the alcohol wash method was the most expensive. Precision, expressed by relative variation, depended on location within the greenhouse, location on greenhouse benches, and the sampling week, but it was generally highest for the flower tapping and desiccation methods. Economic efficiency, expressed by relative net precision, was highest for the flower tapping method and lowest for the alcohol wash method. Advantages and disadvantages are discussed for all three methods used. If relative density assessment methods such as these can all be assumed to accurately estimate a constant proportion of absolute density, then high precision becomes the methodological goal in terms of measuring insect population density, decision making for pest management, and pesticide efficacy assessments.

  1. Precision and accuracy of mechanistic-empirical pavement design

    CSIR Research Space (South Africa)

    Theyse, HL

    2006-09-01

    Full Text Available are discussed in general. The effects of variability and error on the design accuracy and design risk are lastly illustrated at the hand of a simple mechanistic-empirical design problem, showing that the engineering models alone determine the accuracy...

  2. Methodology to Define Delivery Accuracy Under Current Day ATC Operations

    Science.gov (United States)

    Sharma, Shivanjli; Robinson, John E., III

    2015-01-01

    In order to enable arrival management concepts and solutions in a NextGen environment, ground- based sequencing and scheduling functions have been developed to support metering operations in the National Airspace System. These sequencing and scheduling algorithms as well as tools are designed to aid air traffic controllers in developing an overall arrival strategy. The ground systems being developed will support the management of aircraft to their Scheduled Times of Arrival (STAs) at flow-constrained meter points. This paper presents a methodology for determining the undelayed delivery accuracy for current day air traffic control operations. This new method analyzes the undelayed delivery accuracy at meter points in order to understand changes of desired flow rates as well as enabling definition of metrics that will allow near-future ground automation tools to successfully achieve desired separation at the meter points. This enables aircraft to meet their STAs while performing high precision arrivals. The research presents a possible implementation that would allow delivery performance of current tools to be estimated and delivery accuracy requirements for future tools to be defined, which allows analysis of Estimated Time of Arrival (ETA) accuracy for Time-Based Flow Management (TBFM) and the FAA's Traffic Management Advisor (TMA). TMA is a deployed system that generates scheduled time-of-arrival constraints for en- route air traffic controllers in the US. This new method of automated analysis provides a repeatable evaluation of the delay metrics for current day traffic, new releases of TMA, implementation of different tools, and across different airspace environments. This method utilizes a wide set of data from the Operational TMA-TBFM Repository (OTTR) system, which processes raw data collected by the FAA from operational TMA systems at all ARTCCs in the nation. The OTTR system generates daily reports concerning ATC status, intent and actions. Due to its

  3. Improved DORIS accuracy for precise orbit determination and geodesy

    Science.gov (United States)

    Willis, Pascal; Jayles, Christian; Tavernier, Gilles

    2004-01-01

    In 2001 and 2002, 3 more DORIS satellites were launched. Since then, all DORIS results have been significantly improved. For precise orbit determination, 20 cm are now available in real-time with DIODE and 1.5 to 2 cm in post-processing. For geodesy, 1 cm precision can now be achieved regularly every week, making now DORIS an active part of a Global Observing System for Geodesy through the IDS.

  4. Accuracy and precision of oscillometric blood pressure in standing conscious horses

    DEFF Research Database (Denmark)

    Olsen, Emil; Pedersen, Tilde Louise Skovgaard; Robinson, Rebecca

    2016-01-01

    from a teaching and research herd. HYPOTHESIS/OBJECTIVE: To evaluate the accuracy and precision of systolic arterial pressure (SAP), diastolic arterial pressure (DAP), and mean arterial pressure (MAP) in conscious horses obtained with an oscillometric NIBP device when compared to invasively measured...... administration. Agreement analysis with replicate measures was utilized to calculate bias (accuracy) and standard deviation (SD) of bias (precision). RESULTS: A total of 252 pairs of invasive arterial BP and NIBP measurements were analyzed. Compared to the direct BP measures, the NIBP MAP had an accuracy of -4...... mm Hg and precision of 10 mm Hg. SAP had an accuracy of -8 mm Hg and a precision of 17 mm Hg and DAP had an accuracy of -7 mm Hg and a precision of 14 mm Hg. CONCLUSIONS AND CLINICAL RELEVANCE: MAP from the evaluated NIBP monitor is accurate and precise in the adult horse across a range of BP...

  5. Energy helps accuracy: electroweak precision tests at hadron colliders

    CERN Document Server

    Farina, Marco

    2017-09-10

    We show that high energy measurements of Drell-Yan at the LHC can serve as electroweak precision tests. Dimension-6 operators, from the Standard Model Effective Field Theory, modify the high energy behavior of electroweak gauge boson propagators. Existing measurements of the dilepton invariant mass spectrum, from neutral current Drell-Yan at 8 TeV, have comparable sensitivity to LEP. We propose measuring the transverse mass spectrum of charged current Drell-Yan, which can surpass LEP already with 8 TeV data. The 13 TeV LHC will elevate electroweak tests to a new precision frontier.

  6. Energy helps accuracy: Electroweak precision tests at hadron colliders

    Directory of Open Access Journals (Sweden)

    Marco Farina

    2017-09-01

    Full Text Available We show that high energy measurements of Drell–Yan at the LHC can serve as electroweak precision tests. Dimension-6 operators, from the Standard Model Effective Field Theory, modify the high energy behavior of electroweak gauge boson propagators. Existing measurements of the dilepton invariant mass spectrum, from neutral current Drell–Yan at 8 TeV, have comparable sensitivity to LEP. We propose measuring the transverse mass spectrum of charged current Drell–Yan, which can surpass LEP already with 8 TeV data. The 13 TeV LHC will elevate electroweak tests to a new precision frontier.

  7. Precision and Accuracy Parameters in Structured Light 3-D Scanning

    DEFF Research Database (Denmark)

    Eiríksson, Eyþór Rúnar; Wilm, Jakob; Pedersen, David Bue

    2016-01-01

    measure is the established VDI/VDE 2634 (Part 2) guideline using precision made calibration artifacts. Experiments are performed on our own structured light setup, consisting of two cameras and a projector. We place our focus on the influence of calibration design parameters, the calibration procedure...

  8. Students as Toolmakers: Refining the Results in the Accuracy and Precision of a Trigonometric Activity

    Science.gov (United States)

    Igoe, D. P.; Parisi, A. V.; Wagner, S.

    2017-01-01

    Smartphones used as tools provide opportunities for the teaching of the concepts of accuracy and precision and the mathematical concept of arctan. The accuracy and precision of a trigonometric experiment using entirely mechanical tools is compared to one using electronic tools, such as a smartphone clinometer application and a laser pointer. This…

  9. Gamma-Ray Peak Integration: Accuracy and Precision

    International Nuclear Information System (INIS)

    Richard M. Lindstrom

    2000-01-01

    The accuracy of singlet gamma-ray peak areas obtained by a peak analysis program is immaterial. If the same algorithm is used for sample measurement as for calibration and if the peak shapes are similar, then biases in the integration method cancel. Reproducibility is the only important issue. Even the uncertainty of the areas computed by the program is trivial because the true standard uncertainty can be experimentally assessed by repeated measurements of the same source. Reproducible peak integration was important in a recent standard reference material certification task. The primary tool used for spectrum analysis was SUM, a National Institute of Standards and Technology interactive program to sum peaks and subtract a linear background, using the same channels to integrate all 20 spectra. For comparison, this work examines other peak integration programs. Unlike some published comparisons of peak performance in which synthetic spectra were used, this experiment used spectra collected for a real (though exacting) analytical project, analyzed by conventional software used in routine ways. Because both components of the 559- to 564-keV doublet are from 76 As, they were integrated together with SUM. The other programs, however, deconvoluted the peaks. A sensitive test of the fitting algorithm is the ratio of reported peak areas. In almost all the cases, this ratio was much more variable than expected from the reported uncertainties reported by the program. Other comparisons to be reported indicate that peak integration is still an imperfect tool in the analysis of gamma-ray spectra

  10. Spectropolarimetry with PEPSI at the LBT: accuracy vs. precision in magnetic field measurements

    Science.gov (United States)

    Ilyin, Ilya; Strassmeier, Klaus G.; Woche, Manfred; Hofmann, Axel

    2009-04-01

    We present the design of the new PEPSI spectropolarimeter to be installed at the Large Binocular Telescope (LBT) in Arizona to measure the full set of Stokes parameters in spectral lines and outline its precision and the accuracy limiting factors.

  11. Precision and Accuracy of k0-NAA Method for Analysis of Multi Elements in Reference Samples

    International Nuclear Information System (INIS)

    Sri-Wardani

    2004-01-01

    Accuracy and precision of k 0 -NAA method could determine in the analysis of multi elements contained in reference samples. The analyzed results of multi elements in SRM 1633b sample were obtained with optimum results in bias of 20% but it is in a good accuracy and precision. The analyzed results of As, Cd and Zn in CCQM-P29 rice flour sample were obtained with very good result in bias of 0.5 - 5.6%. (author)

  12. The study of the precision and accuracy of quality control in DXA bone mineral densitometry

    International Nuclear Information System (INIS)

    Gong Jian; Xu Hao

    2005-01-01

    Objective: To study the precision and accuracy of quality control (QC) in dual-energy X-ray absorptiometry (DXA) bone mineral densitometry so as to raise the reliability and necessity of the results. Methods: 1) Short-term precision trial: 30 people and 30 SD male rats were chosen, and a precision trail was performed. Each people was scanned twice and reposited in next study. The precision and the least significant change (LSC) of each examinated region were calculated. The short-term precision trail of the rats was performed in the similar way. 2) Accuracy trial: measured the body phantom supplied by factor daily, and compared the results with real value, then calculated the accuracy and correction factor. A Shewhart chart was set up based on average values. Results: 1) People's coefficient of variation (CV) and LSC in the lumbar and proximal femur were 0.7%-2.2% and 0.018-0.048 g/cm 2 . Rats' whole body short-term precision was 0.9%. 2) The average accuracy of DXA densitometer was -0.81%, the correction factor was 0.992. The average bone mineral density measured in successive 25 d was 1.244 g/cm 2 , the standard deviation (SD) was 0.008. Conclusion: The precision and accuracy trail can help to get the information about the working state of the instrument and to analyze the measured results, and can effectively raise the reliability of the measure. (authors)

  13. Convergence Time and Positioning Accuracy Comparison between BDS and GPS Precise Point Positioning

    Directory of Open Access Journals (Sweden)

    ZHANG Xiaohong

    2015-03-01

    Full Text Available BDS/GPS data from MGEX were processed by TriP 2.0 software developed at Wuhan University. Both static and kinematic float PPP are tested by adopting precise satellite orbits and clocks provided by Research Center of GNSS, Wuhan University. The results show that the convergence time of BDS static PPP is about 80min while kinematic PPP is about 100min. For 3h observations, static positioning accuracy of 5 cm and kinematic positioning accuracy of 8 cm in horizontal, about 12 cm in vertical can be achieved. Similar to GPS PPP, precision in east component is worse than north. At present, BDS PPP needs longer convergence time than GPS PPP to reach an absolute positioning accuracy of cm~dm due to the lack of global tracking stations and the limited accuracy of orbit and clock products.

  14. Accuracy of complete-arch dental impressions: a new method of measuring trueness and precision

    OpenAIRE

    Ender, Andreas; Mehl, Albert

    2013-01-01

    STATEMENT OF PROBLEM: A new approach to both 3-dimensional (3D) trueness and precision is necessary to assess the accuracy of intraoral digital impressions and compare them to conventionally acquired impressions. PURPOSE: The purpose of this in vitro study was to evaluate whether a new reference scanner is capable of measuring conventional and digital intraoral complete-arch impressions for 3D accuracy. MATERIAL AND METHODS: A steel reference dentate model was fabricated and measured with a...

  15. Sex differences in accuracy and precision when judging time to arrival: data from two Internet studies.

    Science.gov (United States)

    Sanders, Geoff; Sinclair, Kamila

    2011-12-01

    We report two Internet studies that investigated sex differences in the accuracy and precision of judging time to arrival. We used accuracy to mean the ability to match the actual time to arrival and precision to mean the consistency with which each participant made their judgments. Our task was presented as a computer game in which a toy UFO moved obliquely towards the participant through a virtual three-dimensional space on route to a docking station. The UFO disappeared before docking and participants pressed their space bar at the precise moment they thought the UFO would have docked. Study 1 showed it was possible to conduct quantitative studies of spatiotemporal judgments in virtual reality via the Internet and confirmed reports that men are more accurate because women underestimate, but found no difference in precision measured as intra-participant variation. Study 2 repeated Study 1 with five additional presentations of one condition to provide a better measure of precision. Again, men were more accurate than women but there were no sex differences in precision. However, within the coincidence-anticipation timing (CAT) literature, of those studies that report sex differences, a majority found that males are both more accurate and more precise than females. Noting that many CAT studies report no sex differences, we discuss appropriate interpretations of such null findings. While acknowledging that CAT performance may be influenced by experience we suggest that the sex difference may have originated among our ancestors with the evolutionary selection of men for hunting and women for gathering.

  16. Procedure to determine the two channel timing measurement accuracy and precision of a digital oscilloscope

    International Nuclear Information System (INIS)

    Johnson, M.; Matulik, M.

    1994-01-01

    The digital oscilloscope allows one to make numerous timing measurements, but just how good are those measurements? This document describes a procedure which can be used to determine the accuracy and precision to which a digital oscilloscope can make various two channel timing measurements

  17. Commissioning Procedures for Mechanical Precision and Accuracy in a Dedicated LINAC

    International Nuclear Information System (INIS)

    Ballesteros-Zebadua, P.; Larrga-Gutierrez, J. M.; Garcia-Garduno, O. A.; Juarez, J.; Prieto, I.; Moreno-Jimenez, S.; Celis, M. A.

    2008-01-01

    Mechanical precision measurements are fundamental procedures for the commissioning of a dedicated LINAC. At our Radioneurosurgery Unit, these procedures can be suitable as quality assurance routines that allow the verification of the equipment geometrical accuracy and precision. In this work mechanical tests were performed for gantry and table rotation, obtaining mean associated uncertainties of 0.3 mm and 0.71 mm, respectively. Using an anthropomorphic phantom and a series of localized surface markers, isocenter accuracy showed to be smaller than 0.86 mm for radiosurgery procedures and 0.95 mm for fractionated treatments with mask. All uncertainties were below tolerances. The highest contribution to mechanical variations is due to table rotation, so it is important to correct variations using a localization frame with printed overlays. Mechanical precision knowledge would allow to consider the statistical errors in the treatment planning volume margins

  18. Accuracy and Precision of a Plane Wave Vector Flow Imaging Method in the Healthy Carotid Artery

    DEFF Research Database (Denmark)

    Jensen, Jonas; Villagómez Hoyos, Carlos Armando; Traberg, Marie Sand

    2018-01-01

    The objective of the study described here was to investigate the accuracy and precision of a plane wave 2-D vector flow imaging (VFI) method in laminar and complex blood flow conditions in the healthy carotid artery. The approach was to study (i) the accuracy for complex flow by comparing...... of laminar flow in vivo. The precision in vivo was calculated as the mean standard deviation (SD) of estimates aligned to the heart cycle and was highest in the center of the common carotid artery (SD = 3.6% for velocity magnitudes and 4.5° for angles) and lowest in the external branch and for vortices (SD...... the velocity field from a computational fluid dynamics (CFD) simulation to VFI estimates obtained from the scan of an anthropomorphic flow phantom and from an in vivo scan; (ii) the accuracy for laminar unidirectional flow in vivo by comparing peak systolic velocities from VFI with magnetic resonance...

  19. Detailed precision and accuracy analysis of swarm parameters from a pulsed Townsend experiment

    Science.gov (United States)

    Haefliger, P.; Franck, C. M.

    2018-02-01

    A newly built pulsed Townsend experimental setup which allows one to measure both electron and ion currents is presented. The principle of pulsed Townsend measurements itself is well established to obtain swarm parameters such as the effective ionization rate coefficient, the density-reduced mobility, and the density-normalized longitudinal diffusion coefficient. The main novelty of the present contribution is a detailed and comprehensive analysis of the entire measurement and evaluation chain with respect to accuracy, precision, and reproducibility. The influence of the input parameters (gap distance, applied voltage, measured pressure, and temperature) is analyzed in detail. An overall accuracy of ±0.5% in the density reduced electric field (E/N) is achieved, which is close to the theoretically possible limit using the chosen components. The precision of the experimental results is higher than the accuracy. Through an extensive measurement campaign, the repeatability of our measurements proved to be high and similar to the precision. The reproducibility of results at identical (E/N) is similar to the precision for different distances but decreases for varying pressures. For benchmark purposes, measurements for Ar, CO2, and N2 are presented and compared with our previous experimental setup, simulations, and other experimental references.

  20. A Comparative Study of Precise Point Positioning (PPP Accuracy Using Online Services

    Directory of Open Access Journals (Sweden)

    Malinowski Marcin

    2016-12-01

    Full Text Available Precise Point Positioning (PPP is a technique used to determine the position of receiver antenna without communication with the reference station. It may be an alternative solution to differential measurements, where maintaining a connection with a single RTK station or a regional network of reference stations RTN is necessary. This situation is especially common in areas with poorly developed infrastructure of ground stations. A lot of research conducted so far on the use of the PPP technique has been concerned about the development of entire day observation sessions. However, this paper presents the results of a comparative analysis of accuracy of absolute determination of position from observations which last between 1 to 7 hours with the use of four permanent services which execute calculations with PPP technique such as: Automatic Precise Positioning Service (APPS, Canadian Spatial Reference System Precise Point Positioning (CSRS-PPP, GNSS Analysis and Positioning Software (GAPS and magicPPP - Precise Point Positioning Solution (magicGNSS. On the basis of acquired results of measurements, it can be concluded that at least two-hour long measurements allow acquiring an absolute position with an accuracy of 2-4 cm. An evaluation of the impact on the accuracy of simultaneous positioning of three points test network on the change of the horizontal distance and the relative height difference between measured triangle vertices was also conducted. Distances and relative height differences between points of the triangular test network measured with a laser station Leica TDRA6000 were adopted as references. The analyses of results show that at least two hours long measurement sessions can be used to determine the horizontal distance or the difference in height with an accuracy of 1-2 cm. Rapid products employed in calculations conducted with PPP technique reached the accuracy of determining coordinates on a close level as in elaborations which employ

  1. Accuracy of complete-arch dental impressions: a new method of measuring trueness and precision.

    Science.gov (United States)

    Ender, Andreas; Mehl, Albert

    2013-02-01

    A new approach to both 3-dimensional (3D) trueness and precision is necessary to assess the accuracy of intraoral digital impressions and compare them to conventionally acquired impressions. The purpose of this in vitro study was to evaluate whether a new reference scanner is capable of measuring conventional and digital intraoral complete-arch impressions for 3D accuracy. A steel reference dentate model was fabricated and measured with a reference scanner (digital reference model). Conventional impressions were made from the reference model, poured with Type IV dental stone, scanned with the reference scanner, and exported as digital models. Additionally, digital impressions of the reference model were made and the digital models were exported. Precision was measured by superimposing the digital models within each group. Superimposing the digital models on the digital reference model assessed the trueness of each impression method. Statistical significance was assessed with an independent sample t test (α=.05). The reference scanner delivered high accuracy over the entire dental arch with a precision of 1.6 ±0.6 µm and a trueness of 5.3 ±1.1 µm. Conventional impressions showed significantly higher precision (12.5 ±2.5 µm) and trueness values (20.4 ±2.2 µm) with small deviations in the second molar region (PDigital impressions were significantly less accurate with a precision of 32.4 ±9.6 µm and a trueness of 58.6 ±15.8µm (Pdigital models were visible across the entire dental arch. The new reference scanner is capable of measuring the precision and trueness of both digital and conventional complete-arch impressions. The digital impression is less accurate and shows a different pattern of deviation than the conventional impression. Copyright © 2013 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

  2. Significant improvement of accuracy and precision in the determination of trace rare earths by fluorescence analysis

    International Nuclear Information System (INIS)

    Ozawa, L.; Hersh, H.N.

    1976-01-01

    Most of the rare earths in yttrium, gadolinium and lanthanum oxides emit characteristic fluorescent line spectra under irradiation with photons, electrons and x rays. The sensitivity and selectivity of the rare earth fluorescences are high enough to determine the trace amounts (0.01 to 100 ppM) of rare earths. The absolute fluorescent intensities of solids, however, are markedly affected by the synthesis procedure, level of contamination and crystal perfection, resulting in poor accuracy and low precision for the method (larger than 50 percent error). Special care in preparation of the samples is required to obtain good accuracy and precision. It is found that the accuracy and precision for the determination of trace (less than 10 ppM) rare earths by fluorescence analysis improved significantly, while still maintaining the sensitivity, when the determination is made by comparing the ratio of the fluorescent intensities of the trace rare earths to that of a deliberately added rare earth as reference. The variation in the absolute fluorescent intensity remains, but is compensated for by measuring the fluorescent line intensity ratio. Consequently, the determination of trace rare earths (with less than 3 percent error) is easily made by a photoluminescence technique in which the rare earths are excited directly by photons. Accuracy is still maintained when the absolute fluorescent intensity is reduced by 50 percent through contamination by Ni, Fe, Mn or Pb (about 100 ppM). Determination accuracy is also improved for fluorescence analysis by electron excitation and x-ray excitation. For some rare earths, however, accuracy by these techniques is reduced because indirect excitation mechanisms are involved. The excitation mechanisms and the interferences between rare earths are also reported

  3. Factors that affect the accuracy in the precise radiotherapy for abdomen tumors

    International Nuclear Information System (INIS)

    Yang Tieming; Ju Yongjian

    2008-01-01

    The precise radiotherapy has been widely used in the clinics. But there are many factors that affect the accuracy in the course of implementation. Finally the effect of radiotherapy is affected. These factors are reviewed. And the previous research data about the abdomen tumors is summed up. Also how the accuracy was affected by the respiratory movement, positioning, position fixed technology, weight, retraction and motion of the tumor and the situation of surrounding organs will be analyzed. At last, how to avoid these errors in clinics will be discussed. (authors)

  4. Integrated modeling and analysis methodology for precision pointing applications

    Science.gov (United States)

    Gutierrez, Homero L.

    2002-07-01

    Space-based optical systems that perform tasks such as laser communications, Earth imaging, and astronomical observations require precise line-of-sight (LOS) pointing. A general approach is described for integrated modeling and analysis of these types of systems within the MATLAB/Simulink environment. The approach can be applied during all stages of program development, from early conceptual design studies to hardware implementation phases. The main objective is to predict the dynamic pointing performance subject to anticipated disturbances and noise sources. Secondary objectives include assessing the control stability, levying subsystem requirements, supporting pointing error budgets, and performing trade studies. The integrated model resides in Simulink, and several MATLAB graphical user interfaces (GUI"s) allow the user to configure the model, select analysis options, run analyses, and process the results. A convenient parameter naming and storage scheme, as well as model conditioning and reduction tools and run-time enhancements, are incorporated into the framework. This enables the proposed architecture to accommodate models of realistic complexity.

  5. A measurement control program to meet desired levels of precision and accuracy

    International Nuclear Information System (INIS)

    Bruckner, L.A.

    1991-01-01

    Measurement control programs are usually designed to test for precision and accuracy. Many instruments, however, display non-random data patterns such as biases or seasonal variations which are statistically significant but are of no practical significance. Application of the usual statistical tests can cause these instruments to be removed from service unnecessarily. It is tempting to try to overcome this problem by frequently adjusting the instrument or by arbitrarily changing the parameters of the statistical tests so that failures occur less often. This, of course invalidates the statistical tests. In the author's opinion, the correct way to handle this problem is to identify the desired levels of precision and accuracy, and then to combine these levels with valid statistical techniques in the measurement control-program. This paper describes one way to accomplish this

  6. Accuracy and precision of four common peripheral temperature measurement methods in intensive care patients.

    Science.gov (United States)

    Asadian, Simin; Khatony, Alireza; Moradi, Gholamreza; Abdi, Alireza; Rezaei, Mansour

    2016-01-01

    An accurate determination of body temperature in critically ill patients is a fundamental requirement for initiating the proper process of diagnosis, and also therapeutic actions; therefore, the aim of the study was to assess the accuracy and precision of four noninvasive peripheral methods of temperature measurement compared to the central nasopharyngeal measurement. In this observational prospective study, 237 patients were recruited from the intensive care unit of Imam Ali Hospital of Kermanshah. The patients' body temperatures were measured by four peripheral methods; oral, axillary, tympanic, and forehead along with a standard central nasopharyngeal measurement. After data collection, the results were analyzed by paired t-test, kappa coefficient, receiver operating characteristic curve, and using Statistical Package for the Social Sciences, version 19, software. There was a significant meaningful correlation between all the peripheral methods when compared with the central measurement (Ptemperatures of right and left tympanic membranes and the standard central nasopharyngeal measurement (88%). Paired t-test demonstrated an acceptable precision with forehead (P=0.132), left (P=0.18) and right (P=0.318) tympanic membranes, oral (P=1.00), and axillary (P=1.00) methods. Sensitivity and specificity of both the left and right tympanic membranes were more than for other methods. The tympanic and forehead methods had the highest and lowest accuracy for measuring body temperature, respectively. It is recommended to use the tympanic method (right and left) for assessing a patient's body temperature in the intensive care units because of high accuracy and acceptable precision.

  7. Influence of Waveform Characteristics on LiDAR Ranging Accuracy and Precision

    Science.gov (United States)

    Yang, Bingwei; Xie, Xinhao; Li, Duan

    2018-01-01

    Time of flight (TOF) based light detection and ranging (LiDAR) is a technology for calculating distance between start/stop signals of time of flight. In lab-built LiDAR, two ranging systems for measuring flying time between start/stop signals include time-to-digital converter (TDC) that counts time between trigger signals and analog-to-digital converter (ADC) that processes the sampled start/stop pulses waveform for time estimation. We study the influence of waveform characteristics on range accuracy and precision of two kinds of ranging system. Comparing waveform based ranging (WR) with analog discrete return system based ranging (AR), a peak detection method (WR-PK) shows the best ranging performance because of less execution time, high ranging accuracy, and stable precision. Based on a novel statistic mathematical method maximal information coefficient (MIC), WR-PK precision has a high linear relationship with the received pulse width standard deviation. Thus keeping the received pulse width of measuring a constant distance as stable as possible can improve ranging precision. PMID:29642639

  8. Sternal instability measured with radiostereometric analysis. A study of method feasibility, accuracy and precision.

    Science.gov (United States)

    Vestergaard, Rikke Falsig; Søballe, Kjeld; Hasenkam, John Michael; Stilling, Maiken

    2018-05-18

    A small, but unstable, saw-gap may hinder bone-bridging and induce development of painful sternal dehiscence. We propose the use of Radiostereometric Analysis (RSA) for evaluation of sternal instability and present a method validation. Four bone analogs (phantoms) were sternotomized and tantalum beads were inserted in each half. The models were reunited with wire cerclage and placed in a radiolucent separation device. Stereoradiographs (n = 48) of the phantoms in 3 positions were recorded at 4 imposed separation points. The accuracy and precision was compared statistically and presented as translations along the 3 orthogonal axes. 7 sternotomized patients were evaluated for clinical RSA precision by double-examination stereoradiographs (n = 28). In the phantom study, we found no systematic error (p > 0.3) between the three phantom positions, and precision for evaluation of sternal separation was 0.02 mm. Phantom accuracy was mean 0.13 mm (SD 0.25). In the clinical study, we found a detection limit of 0.42 mm for sternal separation and of 2 mm for anterior-posterior dislocation of the sternal halves for the individual patient. RSA is a precise and low-dose image modality feasible for clinical evaluation of sternal stability in research. ClinicalTrials.gov Identifier: NCT02738437 , retrospectively registered.

  9. Influence of Waveform Characteristics on LiDAR Ranging Accuracy and Precision

    Directory of Open Access Journals (Sweden)

    Xiaolu Li

    2018-04-01

    Full Text Available Time of flight (TOF based light detection and ranging (LiDAR is a technology for calculating distance between start/stop signals of time of flight. In lab-built LiDAR, two ranging systems for measuring flying time between start/stop signals include time-to-digital converter (TDC that counts time between trigger signals and analog-to-digital converter (ADC that processes the sampled start/stop pulses waveform for time estimation. We study the influence of waveform characteristics on range accuracy and precision of two kinds of ranging system. Comparing waveform based ranging (WR with analog discrete return system based ranging (AR, a peak detection method (WR-PK shows the best ranging performance because of less execution time, high ranging accuracy, and stable precision. Based on a novel statistic mathematical method maximal information coefficient (MIC, WR-PK precision has a high linear relationship with the received pulse width standard deviation. Thus keeping the received pulse width of measuring a constant distance as stable as possible can improve ranging precision.

  10. Accuracy, precision, usability, and cost of portable silver test methods for ceramic filter factories.

    Science.gov (United States)

    Meade, Rhiana D; Murray, Anna L; Mittelman, Anjuliee M; Rayner, Justine; Lantagne, Daniele S

    2017-02-01

    Locally manufactured ceramic water filters are one effective household drinking water treatment technology. During manufacturing, silver nanoparticles or silver nitrate are applied to prevent microbiological growth within the filter and increase bacterial removal efficacy. Currently, there is no recommendation for manufacturers to test silver concentrations of application solutions or filtered water. We identified six commercially available silver test strips, kits, and meters, and evaluated them by: (1) measuring in quintuplicate six samples from 100 to 1,000 mg/L (application range) and six samples from 0.0 to 1.0 mg/L (effluent range) of silver nanoparticles and silver nitrate to determine accuracy and precision; (2) conducting volunteer testing to assess ease-of-use; and (3) comparing costs. We found no method accurately detected silver nanoparticles, and accuracy ranged from 4 to 91% measurement error for silver nitrate samples. Most methods were precise, but only one method could test both application and effluent concentration ranges of silver nitrate. Volunteers considered test strip methods easiest. The cost for 100 tests ranged from 36 to 1,600 USD. We found no currently available method accurately and precisely measured both silver types at reasonable cost and ease-of-use, thus these methods are not recommended to manufacturers. We recommend development of field-appropriate methods that accurately and precisely measure silver nanoparticle and silver nitrate concentrations.

  11. Accuracy and precision evaluation of seven self-monitoring blood glucose systems.

    Science.gov (United States)

    Kuo, Chih-Yi; Hsu, Cheng-Teng; Ho, Cheng-Shiao; Su, Ting-En; Wu, Ming-Hsun; Wang, Chau-Jong

    2011-05-01

    Self-monitoring blood glucose (SMBG) systems play a critical role in management of diabetes. SMBG systems should at least meet the minimal requirement of the World Health Organization's ISO 15197:2003. For tight glycemic control, a tighter accuracy requirement is needed. Seven SMBG systems were evaluated for accuracy and precision: Bionime Rightest(™) GM550 (Bionime Corp., Dali City, Taiwan), Accu-Chek(®) Performa (Roche Diagnostics, Indianapolis, IN), OneTouch(®) Ultra(®)2 (LifeScan Inc., Milpitas, CA), MediSense(®) Optium(™) Xceed (Abbott Diabetes Care Inc., Alameda, CA), Medisafe (TERUMO Corp., Tokyo, Japan), Fora(®) TD4227 (Taidac Technology Corp., Wugu Township, Taiwan), and Ascensia Contour(®) (Bayer HealthCare LLC, Mishawaka, IN). The 107 participants (44 men and 63 women) were between 23 and 91 years old. The analytical results of seven SMBG systems were compared with those of plasma analyzed with the hexokinase method (Olympus AU640, Olympus America Inc., Center Valley, PA). The imprecision of the seven blood glucose meters ranged from 1.1% to 4.7%. Three of the seven blood glucose meters (42.9%) fulfilled the minimum accuracy criteria of ISO 15197:2003. The mean absolute relative error value for each blood glucose meter was calculated and ranged from 6.5% to 12.0%. More than 40% of evaluated SMBG systems meet the minimal accuracy criteria requirement of ISO 15197:2003. However, considering tighter criteria for accuracy of ±15%, only the Bionime Rightest GM550 meets this requirement. Because SMBG systems play a critical role in management of diabetes, manufacturers have to strive to improve accuracy and precision and to ensure the good quality of blood glucose meters and test strips.

  12. Accuracy of 3D white light scanning of abutment teeth impressions: evaluation of trueness and precision.

    Science.gov (United States)

    Jeon, Jin-Hun; Kim, Hae-Young; Kim, Ji-Hwan; Kim, Woong-Chul

    2014-12-01

    This study aimed to evaluate the accuracy of digitizing dental impressions of abutment teeth using a white light scanner and to compare the findings among teeth types. To assess precision, impressions of the canine, premolar, and molar prepared to receive all-ceramic crowns were repeatedly scanned to obtain five sets of 3-D data (STL files). Point clouds were compared and error sizes were measured (n=10 per type). Next, to evaluate trueness, impressions of teeth were rotated by 10°-20° and scanned. The obtained data were compared with the first set of data for precision assessment, and the error sizes were measured (n=5 per type). The Kruskal-Wallis test was performed to evaluate precision and trueness among three teeth types, and post-hoc comparisons were performed using the Mann-Whitney U test with Bonferroni correction (α=.05). Precision discrepancies for the canine, premolar, and molar were 3.7 µm, 3.2 µm, and 7.3 µm, respectively, indicating the poorest precision for the molar (Pimpressions of abutment teeth using a white light scanner was assessed to be a highly accurate method and provided discrepancy values in a clinically acceptable range. Further study is needed to improve digitizing performance of white light scanning in axial wall.

  13. Finite Precision Logistic Map between Computational Efficiency and Accuracy with Encryption Applications

    Directory of Open Access Journals (Sweden)

    Wafaa S. Sayed

    2017-01-01

    Full Text Available Chaotic systems appear in many applications such as pseudo-random number generation, text encryption, and secure image transfer. Numerical solutions of these systems using digital software or hardware inevitably deviate from the expected analytical solutions. Chaotic orbits produced using finite precision systems do not exhibit the infinite period expected under the assumptions of infinite simulation time and precision. In this paper, digital implementation of the generalized logistic map with signed parameter is considered. We present a fixed-point hardware realization of a Pseudo-Random Number Generator using the logistic map that experiences a trade-off between computational efficiency and accuracy. Several introduced factors such as the used precision, the order of execution of the operations, parameter, and initial point values affect the properties of the finite precision map. For positive and negative parameter cases, the studied properties include bifurcation points, output range, maximum Lyapunov exponent, and period length. The performance of the finite precision logistic map is compared in the two cases. A basic stream cipher system is realized to evaluate the system performance for encryption applications for different bus sizes regarding the encryption key size, hardware requirements, maximum clock frequency, NIST and correlation, histogram, entropy, and Mean Absolute Error analyses of encrypted images.

  14. Evaluation of Different Estimation Methods for Accuracy and Precision in Biological Assay Validation.

    Science.gov (United States)

    Yu, Binbing; Yang, Harry

    2017-01-01

    Biological assays ( bioassays ) are procedures to estimate the potency of a substance by studying its effects on living organisms, tissues, and cells. Bioassays are essential tools for gaining insight into biologic systems and processes including, for example, the development of new drugs and monitoring environmental pollutants. Two of the most important parameters of bioassay performance are relative accuracy (bias) and precision. Although general strategies and formulas are provided in USP, a comprehensive understanding of the definitions of bias and precision remain elusive. Additionally, whether there is a beneficial use of data transformation in estimating intermediate precision remains unclear. Finally, there are various statistical estimation methods available that often pose a dilemma for the analyst who must choose the most appropriate method. To address these issues, we provide both a rigorous definition of bias and precision as well as three alternative methods for calculating relative standard deviation (RSD). All methods perform similarly when the RSD ≤10%. However, the USP estimates result in larger bias and root-mean-square error (RMSE) compared to the three proposed methods when the actual variation was large. Therefore, the USP method should not be used for routine analysis. For data with moderate skewness and deviation from normality, the estimates based on the original scale perform well. The original scale method is preferred, and the method based on log-transformation may be used for noticeably skewed data. LAY ABSTRACT: Biological assays, or bioassays, are essential in the development and manufacture of biopharmaceutical products for potency testing and quality monitoring. Two important parameters of assay performance are relative accuracy (bias) and precision. The definitions of bias and precision in USP 〈1033〉 are elusive and confusing. Another complicating issue is whether log-transformation should be used for calculating the

  15. A Proposed Methodology to Assess the Accuracy of 3D Scanners and Casts and Monitor Tooth Wear Progression in Patients.

    Science.gov (United States)

    Ahmed, Khaled E; Whitters, John; Ju, Xiangyang; Pierce, S Gareth; MacLeod, Charles N; Murray, Colin A

    2016-01-01

    The aim of this study was to detail and assess the capability of a novel methodology to 3D-quantify tooth wear progression in a patient over a period of 12 months. A calibrated stainless steel model was used to identify the accuracy of the scanning system by assessing the accuracy and precision of the contact scanner and the dimensional accuracy and stability of casts fabricated from three different types of impression materials. Thereafter, the overall accuracy of the 3D scanning system (scanner and casts) was ascertained. Clinically, polyether impressions were made of the patient's dentition at the initial examination and at the 12-month review, then poured in type IV dental stone to assess the tooth wear. The anterior teeth on the resultant casts were scanned, and images were analyzed using 3D matching software to detect dimensional variations between the patient's impressions. The accuracy of the 3D scanning system was established to be 33 μm. 3D clinical analysis demonstrated localized wear on the incisal and palatal surfaces of the patient's maxillary central incisors. The identified wear extended to a depth of 500 μm with a distribution of 4% to 7% of affected tooth surfaces. The newly developed 3D scanning methodology was found to be capable of assessing and accounting for the various factors affecting tooth wear scanning. Initial clinical evaluation of the methodology demonstrates successful monitoring of tooth wear progression. However, further clinical assessment is needed.

  16. Methodology for GPS Synchronization Evaluation with High Accuracy

    OpenAIRE

    Li Zan; Braun Torsten; Dimitrova Desislava

    2015-01-01

    Clock synchronization in the order of nanoseconds is one of the critical factors for time based localization. Currently used time synchronization methods are developed for the more relaxed needs of network operation. Their usability for positioning should be carefully evaluated. In this paper we are particularly interested in GPS based time synchronization. To judge its usability for localization we need a method that can evaluate the achieved time synchronization with nanosecond accuracy. Ou...

  17. Methodology for GPS Synchronization Evaluation with High Accuracy

    OpenAIRE

    Li, Zan; Braun, Torsten; Dimitrova, Desislava Cvetanova

    2015-01-01

    Clock synchronization in the order of nanoseconds is one of the critical factors for time-based localization. Currently used time synchronization methods are developed for the more relaxed needs of network operation. Their usability for positioning should be carefully evaluated. In this paper, we are particularly interested in GPS-based time synchronization. To judge its usability for localization we need a method that can evaluate the achieved time synchronization with nanosecond accuracy. O...

  18. Accuracy and precision of protein-ligand interaction kinetics determined from chemical shift titrations

    Energy Technology Data Exchange (ETDEWEB)

    Markin, Craig J.; Spyracopoulos, Leo, E-mail: leo.spyracopoulos@ualberta.ca [University of Alberta, Department of Biochemistry (Canada)

    2012-12-15

    NMR-monitored chemical shift titrations for the study of weak protein-ligand interactions represent a rich source of information regarding thermodynamic parameters such as dissociation constants (K{sub D}) in the micro- to millimolar range, populations for the free and ligand-bound states, and the kinetics of interconversion between states, which are typically within the fast exchange regime on the NMR timescale. We recently developed two chemical shift titration methods wherein co-variation of the total protein and ligand concentrations gives increased precision for the K{sub D} value of a 1:1 protein-ligand interaction (Markin and Spyracopoulos in J Biomol NMR 53: 125-138, 2012). In this study, we demonstrate that classical line shape analysis applied to a single set of {sup 1}H-{sup 15}N 2D HSQC NMR spectra acquired using precise protein-ligand chemical shift titration methods we developed, produces accurate and precise kinetic parameters such as the off-rate (k{sub off}). For experimentally determined kinetics in the fast exchange regime on the NMR timescale, k{sub off} {approx} 3,000 s{sup -1} in this work, the accuracy of classical line shape analysis was determined to be better than 5 % by conducting quantum mechanical NMR simulations of the chemical shift titration methods with the magnetic resonance toolkit GAMMA. Using Monte Carlo simulations, the experimental precision for k{sub off} from line shape analysis of NMR spectra was determined to be 13 %, in agreement with the theoretical precision of 12 % from line shape analysis of the GAMMA simulations in the presence of noise and protein concentration errors. In addition, GAMMA simulations were employed to demonstrate that line shape analysis has the potential to provide reasonably accurate and precise k{sub off} values over a wide range, from 100 to 15,000 s{sup -1}. The validity of line shape analysis for k{sub off} values approaching intermediate exchange ({approx}100 s{sup -1}), may be facilitated by

  19. Accuracy and precision of protein–ligand interaction kinetics determined from chemical shift titrations

    International Nuclear Information System (INIS)

    Markin, Craig J.; Spyracopoulos, Leo

    2012-01-01

    NMR-monitored chemical shift titrations for the study of weak protein–ligand interactions represent a rich source of information regarding thermodynamic parameters such as dissociation constants (K D ) in the micro- to millimolar range, populations for the free and ligand-bound states, and the kinetics of interconversion between states, which are typically within the fast exchange regime on the NMR timescale. We recently developed two chemical shift titration methods wherein co-variation of the total protein and ligand concentrations gives increased precision for the K D value of a 1:1 protein–ligand interaction (Markin and Spyracopoulos in J Biomol NMR 53: 125–138, 2012). In this study, we demonstrate that classical line shape analysis applied to a single set of 1 H– 15 N 2D HSQC NMR spectra acquired using precise protein–ligand chemical shift titration methods we developed, produces accurate and precise kinetic parameters such as the off-rate (k off ). For experimentally determined kinetics in the fast exchange regime on the NMR timescale, k off ∼ 3,000 s −1 in this work, the accuracy of classical line shape analysis was determined to be better than 5 % by conducting quantum mechanical NMR simulations of the chemical shift titration methods with the magnetic resonance toolkit GAMMA. Using Monte Carlo simulations, the experimental precision for k off from line shape analysis of NMR spectra was determined to be 13 %, in agreement with the theoretical precision of 12 % from line shape analysis of the GAMMA simulations in the presence of noise and protein concentration errors. In addition, GAMMA simulations were employed to demonstrate that line shape analysis has the potential to provide reasonably accurate and precise k off values over a wide range, from 100 to 15,000 s −1 . The validity of line shape analysis for k off values approaching intermediate exchange (∼100 s −1 ), may be facilitated by more accurate K D measurements from NMR

  20. Accuracy and precision of protein-ligand interaction kinetics determined from chemical shift titrations.

    Science.gov (United States)

    Markin, Craig J; Spyracopoulos, Leo

    2012-12-01

    NMR-monitored chemical shift titrations for the study of weak protein-ligand interactions represent a rich source of information regarding thermodynamic parameters such as dissociation constants (K ( D )) in the micro- to millimolar range, populations for the free and ligand-bound states, and the kinetics of interconversion between states, which are typically within the fast exchange regime on the NMR timescale. We recently developed two chemical shift titration methods wherein co-variation of the total protein and ligand concentrations gives increased precision for the K ( D ) value of a 1:1 protein-ligand interaction (Markin and Spyracopoulos in J Biomol NMR 53: 125-138, 2012). In this study, we demonstrate that classical line shape analysis applied to a single set of (1)H-(15)N 2D HSQC NMR spectra acquired using precise protein-ligand chemical shift titration methods we developed, produces accurate and precise kinetic parameters such as the off-rate (k ( off )). For experimentally determined kinetics in the fast exchange regime on the NMR timescale, k ( off ) ~ 3,000 s(-1) in this work, the accuracy of classical line shape analysis was determined to be better than 5 % by conducting quantum mechanical NMR simulations of the chemical shift titration methods with the magnetic resonance toolkit GAMMA. Using Monte Carlo simulations, the experimental precision for k ( off ) from line shape analysis of NMR spectra was determined to be 13 %, in agreement with the theoretical precision of 12 % from line shape analysis of the GAMMA simulations in the presence of noise and protein concentration errors. In addition, GAMMA simulations were employed to demonstrate that line shape analysis has the potential to provide reasonably accurate and precise k ( off ) values over a wide range, from 100 to 15,000 s(-1). The validity of line shape analysis for k ( off ) values approaching intermediate exchange (~100 s(-1)), may be facilitated by more accurate K ( D ) measurements

  1. Precision and accuracy of the static GNSS system for surveying networks used in Civil Engineering

    Directory of Open Access Journals (Sweden)

    Nixon Alexander Correa Muñoz

    2018-01-01

    Full Text Available A field check was implemented for calibrating surveying equipment. It was geo-referenced with a Total Station Theodolite and by implementing procedures concerning repeatability and reproducibility. We carried out GNSS (Global Navigation Satellite System static positioning with double frequency equipment, sensitizing occupation times, day times, uncorrected coordinates subjected to a differential correction procedure and type of coordinates obtained. This facilitated an evaluation of precision and accuracy for the GNSS positioning with the static method, which gave a global RMSE (root mean square error of 1 cm for conditions with no multipath effect and 4 cm for field calibration points close to buildings. Additionally, optimal results for occupation times of 30 minutes were found, and the need to use planar Cartesian coordinates to ensure compatibility with the surveys using electronic measurement of distances, which allows the use of the static GNSS positioning for geo-referencing precise surveying networks, and can be used in different applications in Civil Engineering.

  2. Improved precision and accuracy for microarrays using updated probe set definitions

    Directory of Open Access Journals (Sweden)

    Larsson Ola

    2007-02-01

    Full Text Available Abstract Background Microarrays enable high throughput detection of transcript expression levels. Different investigators have recently introduced updated probe set definitions to more accurately map probes to our current knowledge of genes and transcripts. Results We demonstrate that updated probe set definitions provide both better precision and accuracy in probe set estimates compared to the original Affymetrix definitions. We show that the improved precision mainly depends on the increased number of probes that are integrated into each probe set, but we also demonstrate an improvement when the same number of probes is used. Conclusion Updated probe set definitions does not only offer expression levels that are more accurately associated to genes and transcripts but also improvements in the estimated transcript expression levels. These results give support for the use of updated probe set definitions for analysis and meta-analysis of microarray data.

  3. Accuracy and precision of four common peripheral temperature measurement methods in intensive care patients

    Directory of Open Access Journals (Sweden)

    Asadian S

    2016-09-01

    Full Text Available Simin Asadian,1 Alireza Khatony,1 Gholamreza Moradi,2 Alireza Abdi,1 Mansour Rezaei,3 1Nursing and Midwifery School, Kermanshah University of Medical Sciences, 2Department of Anesthesiology, 3Biostatistics & Epidemiology Department, Kermanshah University of Medical Sciences, Kermanshah, Iran Introduction: An accurate determination of body temperature in critically ill patients is a fundamental requirement for initiating the proper process of diagnosis, and also therapeutic actions; therefore, the aim of the study was to assess the accuracy and precision of four noninvasive peripheral methods of temperature measurement compared to the central nasopharyngeal measurement. Methods: In this observational prospective study, 237 patients were recruited from the intensive care unit of Imam Ali Hospital of Kermanshah. The patients’ body temperatures were measured by four peripheral methods; oral, axillary, tympanic, and forehead along with a standard central nasopharyngeal measurement. After data collection, the results were analyzed by paired t-test, kappa coefficient, receiver operating characteristic curve, and using Statistical Package for the Social Sciences, version 19, software. Results: There was a significant meaningful correlation between all the peripheral methods when compared with the central measurement (P<0.001. Kappa coefficients showed good agreement between the temperatures of right and left tympanic membranes and the standard central nasopharyngeal measurement (88%. Paired t-test demonstrated an acceptable precision with forehead (P=0.132, left (P=0.18 and right (P=0.318 tympanic membranes, oral (P=1.00, and axillary (P=1.00 methods. Sensitivity and specificity of both the left and right tympanic membranes were more than for other methods. Conclusion: The tympanic and forehead methods had the highest and lowest accuracy for measuring body temperature, respectively. It is recommended to use the tympanic method (right and left for

  4. Precision and accuracy, two steps towards the standardization of XRPD measurements

    Energy Technology Data Exchange (ETDEWEB)

    Berti, G [Pisa Univ. (Italy). Dept. of Earth Sciences

    1996-09-01

    Any standardization process requires to get at results comprehensible, reproducible and traceable. Precision and accuracy of the measurements play a key role in getting at these requirements. The adoption of either physical (standard) or mathematical models allows for describing the whole diffraction measurement process with the necessary physical significance. From an other hand, the adoption of procedure, which are capable of controlling the measurement process, renders it reproducible and traceable. The falling of those requirements make difficult to transfer or replicate elsewhere experiences which may give even excellent result in a given laboratory.

  5. Precision and accuracy, two steps towards the standardization of XRPD measurements

    International Nuclear Information System (INIS)

    Berti, G.

    1996-01-01

    Any standardization process requires to get at results comprehensible, reproducible and traceable. Precision and accuracy of the measurements play a key role in getting at these requirements. The adoption of either physical (standard) or mathematical models allows for describing the whole diffraction measurement process with the necessary physical significance. From an other hand, the adoption of procedure, which are capable of controlling the measurement process, renders it reproducible and traceable. The falling of those requirements make difficult to transfer or replicate elsewhere experiences which may give even excellent result in a given laboratory

  6. Shape Accuracy of Iron Precision Castings in Terms of Ceramic Moulds Physical Properties Anisotropy

    Directory of Open Access Journals (Sweden)

    Biernacki R.

    2014-03-01

    Full Text Available While analyzing shape accuracy of ferroalloy precision castings in terms of ceramic moulds physical anisotropy, low-alloy steel castings ("cover" and cast iron ("plate" were included. The basic parameters in addition to the product linear shape accuracy are flatness deviations, especially due to the expanded flat surface which is cast plate. For mentioned castings surface micro-geometry analysis was also carried, favoring surface load capacity tp50 for Rmax = 50%. Surface load capacity tp50 obtained for the cast cover was compared with machined product, and casting plate surface was compared with wear part of the conveyor belt. The results were referred to anisotropy of ceramic moulds physical properties, which was evaluated by studying ceramic moulds samples in computer tomography equipment Metrotom 800

  7. Trace element analysis by EPMA in geosciences: detection limit, precision and accuracy

    Science.gov (United States)

    Batanova, V. G.; Sobolev, A. V.; Magnin, V.

    2018-01-01

    Use of the electron probe microanalyser (EPMA) for trace element analysis has increased over the last decade, mainly because of improved stability of spectrometers and the electron column when operated at high probe current; development of new large-area crystal monochromators and ultra-high count rate spectrometers; full integration of energy-dispersive / wavelength-dispersive X-ray spectrometry (EDS/WDS) signals; and the development of powerful software packages. For phases that are stable under a dense electron beam, the detection limit and precision can be decreased to the ppm level by using high acceleration voltage and beam current combined with long counting time. Data on 10 elements (Na, Al, P, Ca, Ti, Cr, Mn, Co, Ni, Zn) in olivine obtained on a JEOL JXA-8230 microprobe with tungsten filament show that the detection limit decreases proportionally to the square root of counting time and probe current. For all elements equal or heavier than phosphorus (Z = 15), the detection limit decreases with increasing accelerating voltage. The analytical precision for minor and trace elements analysed in olivine at 25 kV accelerating voltage and 900 nA beam current is 4 - 18 ppm (2 standard deviations of repeated measurements of the olivine reference sample) and is similar to the detection limit of corresponding elements. To analyse trace elements accurately requires careful estimation of background, and consideration of sample damage under the beam and secondary fluorescence from phase boundaries. The development and use of matrix reference samples with well-characterised trace elements of interest is important for monitoring and improving of the accuracy. An evaluation of the accuracy of trace element analyses in olivine has been made by comparing EPMA data for new reference samples with data obtained by different in-situ and bulk analytical methods in six different laboratories worldwide. For all elements, the measured concentrations in the olivine reference sample

  8. Accuracy assessment of Precise Point Positioning with multi-constellation GNSS data under ionospheric scintillation effects

    Directory of Open Access Journals (Sweden)

    Marques Haroldo Antonio

    2018-01-01

    Full Text Available GPS and GLONASS are currently the Global Navigation Satellite Systems (GNSS with full operational capacity. The integration of GPS, GLONASS and future GNSS constellations can provide better accuracy and more reliability in geodetic positioning, in particular for kinematic Precise Point Positioning (PPP, where the satellite geometry is considered a limiting factor to achieve centimeter accuracy. The satellite geometry can change suddenly in kinematic positioning in urban areas or under conditions of strong atmospheric effects such as for instance ionospheric scintillation that may degrade satellite signal quality, causing cycle slips and even loss of lock. Scintillation is caused by small scale irregularities in the ionosphere and is characterized by rapid changes in amplitude and phase of the signal, which are more severe in equatorial and high latitudes geomagnetic regions. In this work, geodetic positioning through the PPP method was evaluated with integrated GPS and GLONASS data collected in the equatorial region under varied scintillation conditions. The GNSS data were processed in kinematic PPP mode and the analyses show accuracy improvements of up to 60% under conditions of strong scintillation when using multi-constellation data instead of GPS data alone. The concepts and analyses related to the ionospheric scintillation effects, the mathematical model involved in PPP with GPS and GLONASS data integration as well as accuracy assessment with data collected under ionospheric scintillation effects are presented.

  9. Accuracy assessment of Precise Point Positioning with multi-constellation GNSS data under ionospheric scintillation effects

    Science.gov (United States)

    Marques, Haroldo Antonio; Marques, Heloísa Alves Silva; Aquino, Marcio; Veettil, Sreeja Vadakke; Monico, João Francisco Galera

    2018-02-01

    GPS and GLONASS are currently the Global Navigation Satellite Systems (GNSS) with full operational capacity. The integration of GPS, GLONASS and future GNSS constellations can provide better accuracy and more reliability in geodetic positioning, in particular for kinematic Precise Point Positioning (PPP), where the satellite geometry is considered a limiting factor to achieve centimeter accuracy. The satellite geometry can change suddenly in kinematic positioning in urban areas or under conditions of strong atmospheric effects such as for instance ionospheric scintillation that may degrade satellite signal quality, causing cycle slips and even loss of lock. Scintillation is caused by small scale irregularities in the ionosphere and is characterized by rapid changes in amplitude and phase of the signal, which are more severe in equatorial and high latitudes geomagnetic regions. In this work, geodetic positioning through the PPP method was evaluated with integrated GPS and GLONASS data collected in the equatorial region under varied scintillation conditions. The GNSS data were processed in kinematic PPP mode and the analyses show accuracy improvements of up to 60% under conditions of strong scintillation when using multi-constellation data instead of GPS data alone. The concepts and analyses related to the ionospheric scintillation effects, the mathematical model involved in PPP with GPS and GLONASS data integration as well as accuracy assessment with data collected under ionospheric scintillation effects are presented.

  10. Estimates of laboratory accuracy and precision on Hanford waste tank samples

    International Nuclear Information System (INIS)

    Dodd, D.A.

    1995-01-01

    A review was performed on three sets of analyses generated in Battelle, Pacific Northwest Laboratories and three sets generated by Westinghouse Hanford Company, 222-S Analytical Laboratory. Laboratory accuracy and precision was estimated by analyte and is reported in tables. The sources used to generate this estimate is of limited size but does include the physical forms, liquid and solid, which are representative of samples from tanks to be characterized. This estimate was published as an aid to programs developing data quality objectives in which specified limits are established. Data resulting from routine analyses of waste matrices can be expected to be bounded by the precision and accuracy estimates of the tables. These tables do not preclude or discourage direct negotiations between program and laboratory personnel while establishing bounding conditions. Programmatic requirements different than those listed may be reliably met on specific measurements and matrices. It should be recognized, however, that these are specific to waste tank matrices and may not be indicative of performance on samples from other sources

  11. Precision and Accuracy of a Digital Impression Scanner in Full-Arch Implant Rehabilitation.

    Science.gov (United States)

    Pesce, Paolo; Pera, Francesco; Setti, Paolo; Menini, Maria

    To evaluate the accuracy and precision of a digital scanner used to scan four implants positioned according to an immediate loading implant protocol and to assess the accuracy of an aluminum framework fabricated from a digital impression. Five master casts reproducing different edentulous maxillae with four tilted implants were used. Four scan bodies were screwed onto the low-profile abutments, and a digital intraoral scanner was used to perform five digital impressions of each master cast. To assess trueness, a metal framework of the best digital impression was produced with computer-aided design/computer-assisted manufacture (CAD/CAM) technology and passive fit was assessed with the Sheffield test. Gaps between the frameworks and the implant analogs were measured with a stereomicroscope. To assess precision, three-dimensional (3D) point cloud processing software was used to measure the deviations between the five digital impressions of each cast by producing a color map. The deviation values were grouped in three classes, and differences were assessed between class 2 (representing lower discrepancies) and the assembled classes 1 and 3 (representing the higher negative and positive discrepancies, respectively). The frameworks showed a mean gap of 3D point cloud software, with higher frequencies of points in class 2 than in grouped classes 1 and 3 (P impression may represent a reliable method for fabricating full-arch implant frameworks with good passive fit when tilted implants are present.

  12. [Accuracy, precision and speed of parenteral nutrition admixture bags manufacturing: comparison between automated and manual methods].

    Science.gov (United States)

    Zegbeh, H; Pirot, F; Quessada, T; Durand, T; Vételé, F; Rose, A; Bréant, V; Aulagner, G

    2011-01-01

    The parenteral nutrition admixture (PNA) manufacturing in hospital pharmacy is realized by aseptic transfer (AT) or sterilizing filtration (SF). The development of filling systems for PNA manufacturing requires, without standard, an evaluation comparing to traditional methods of SF. The filling accuracy of automated AT and SF was evaluated by mass and physical-chemistry tests in repeatability conditions (identical composition of PNA; n=five bags) and reproducibility conditions (different composition of PNA; n=57 bags). For each manufacturing method, the filling precision and the average time for PNA bags manufacturing were evaluated starting from an identical composition and volume PNA (n=five trials). Both manufacturing methods did not show significant difference of accuracy. Precision of both methods was lower than limits generally admitted for acceptability of mass and physical-chemistry tests. However, the manufacturing time for SF was superior (five different binary admixtures in five bags) or inferior (one identical binary admixture in five bags) to time recorded for automated AT. We show that serial manufacturing of PNA bags by SF with identical composition is faster than automated AT. Nevertheless, automated AT is faster than SF in variable composition of PNA. The manufacturing method choice will be motivate by the nature (i. e., variable composition or not) of the manufactured bags. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

  13. Accuracy improvement techniques in Precise Point Positioning method using multiple GNSS constellations

    Science.gov (United States)

    Vasileios Psychas, Dimitrios; Delikaraoglou, Demitris

    2016-04-01

    The future Global Navigation Satellite Systems (GNSS), including modernized GPS, GLONASS, Galileo and BeiDou, offer three or more signal carriers for civilian use and much more redundant observables. The additional frequencies can significantly improve the capabilities of the traditional geodetic techniques based on GPS signals at two frequencies, especially with regard to the availability, accuracy, interoperability and integrity of high-precision GNSS applications. Furthermore, highly redundant measurements can allow for robust simultaneous estimation of static or mobile user states including more parameters such as real-time tropospheric biases and more reliable ambiguity resolution estimates. This paper presents an investigation and analysis of accuracy improvement techniques in the Precise Point Positioning (PPP) method using signals from the fully operational (GPS and GLONASS), as well as the emerging (Galileo and BeiDou) GNSS systems. The main aim was to determine the improvement in both the positioning accuracy achieved and the time convergence it takes to achieve geodetic-level (10 cm or less) accuracy. To this end, freely available observation data from the recent Multi-GNSS Experiment (MGEX) of the International GNSS Service, as well as the open source program RTKLIB were used. Following a brief background of the PPP technique and the scope of MGEX, the paper outlines the various observational scenarios that were used in order to test various data processing aspects of PPP solutions with multi-frequency, multi-constellation GNSS systems. Results from the processing of multi-GNSS observation data from selected permanent MGEX stations are presented and useful conclusions and recommendations for further research are drawn. As shown, data fusion from GPS, GLONASS, Galileo and BeiDou systems is becoming increasingly significant nowadays resulting in a position accuracy increase (mostly in the less favorable East direction) and a large reduction of convergence

  14. [Precision and accuracy of a dental spectrophotometer in gingival color measurement of maxillary anterior gingival].

    Science.gov (United States)

    Du, Yang; Tan, Jian-guo; Chen, Li; Wang, Fang-ping; Tan, Yao; Zhou, Jian-feng

    2012-08-18

    To explore a gingival shade matching method and to evaluate the precision and accuracy of a dental spectrophotometer modified to be used in gingival color measurement. Crystaleye, a dental spectrophotometer (Olympus, Tokyo, Japan) with a custom shading cover was tested. For precision assessment, two experienced experimenters measured anterior maxillary incisors five times for each tooth. A total of 20 healthy gingival sites (attached gingiva, free gingiva and medial gingival papilla in anterior maxillary region) were measured,the Commission Internationale de I' Eclairage (CIE) color parameters (CIE L*a*b*) of which were analyzed using the supporting software. For accuracy assessment, a rectangular area of approximately 3 mm×3 mm was chosen in the attached gingival portion for spectral analysis. PR715 (SpectraScan;Photo Research Inc.,California, USA), a spectroradiometer, was utilized as standard control. Average color differences (ΔE) between the values from PR715 and Crystaleye were calculated. In precision assessment,ΔL* between the values in all the test sites and average values were from(0.28±0.16)to(0.78±0.57), with Δa*and Δb* from(0.28±0.15)to (0.87±0.65),from(0.19±0.09)to( 0.58±0.78), respectively. Average ΔE between values in all test sites and average values were from (0.62 ± 0.17) to (1.25 ± 0.98) CIELAB units, with a total average ΔE(0.90 ± 0.18). In accuracy assessment, ΔL* with control device were from(0.58±0.50)to(2.22±1.89),with Δa*and Δb* from(1.03±0.67)to(2.99±1.32),from(0.68±0.78)to(1.26±0.83), respectively. Average ΔE with the control device were from (2.44±0.82) to (3.51±1.03) CIELAB units, with a total average ΔE (2.96 ± 1.08). With appropriate modification, Crystaleye, the spectrophotometer, has demonstrated relative minor color variations that can be useful in gingival color measurement.

  15. Technical accuracy of a neuronavigation system measured with a high-precision mechanical micromanipulator.

    Science.gov (United States)

    Kaus, M; Steinmeier, R; Sporer, T; Ganslandt, O; Fahlbusch, R

    1997-12-01

    This study was designed to determine and evaluate the different system-inherent sources of erroneous target localization of a light-emitting diode (LED)-based neuronavigation system (StealthStation, Stealth Technologies, Boulder, CO). The localization accuracy was estimated by applying a high-precision mechanical micromanipulator to move and exactly locate (+/- 0.1 micron) the pointer at multiple positions in the physical three-dimensional space. The localization error was evaluated by calculating the spatial distance between the (known) LED positions and the LED coordinates measured by the neuronavigator. The results are based on a study of approximately 280,000 independent coordinate measurements. The maximum localization error detected was 0.55 +/- 0.29 mm, with the z direction (distance to the camera array) being the most erroneous coordinate. Minimum localization error was found at a distance of 1400 mm from the central camera (optimal measurement position). Additional error due to 1) mechanical vibrations of the camera tripod (+/- 0.15 mm) and the reference frame (+/- 0.08 mm) and 2) extrapolation of the pointer tip position from the LED coordinates of at least +/- 0.12 mm were detected, leading to a total technical error of 0.55 +/- 0.64 mm. Based on this technical accuracy analysis, a set of handling recommendations is proposed, leading to an improved localization accuracy. The localization error could be reduced by 0.3 +/- 0.15 mm by correct camera positioning (1400 mm distance) plus 0.15 mm by vibration-eliminating fixation of the camera. Correct handling of the probe during the operation may improve the accuracy by up to 0.1 mm.

  16. Methods used by Elsam for monitoring precision and accuracy of analytical results

    Energy Technology Data Exchange (ETDEWEB)

    Hinnerskov Jensen, J [Soenderjyllands Hoejspaendingsvaerk, Faelleskemikerne, Aabenraa (Denmark)

    1996-12-01

    Performing round robins at regular intervals is the primary method used by ELsam for monitoring precision and accuracy of analytical results. The firs round robin was started in 1974, and today 5 round robins are running. These are focused on: boiler water and steam, lubricating oils, coal, ion chromatography and dissolved gases in transformer oils. Besides the power plant laboratories in Elsam, the participants are power plant laboratories from the rest of Denmark, industrial and commercial laboratories in Denmark, and finally foreign laboratories. The calculated standard deviations or reproducibilities are compared with acceptable values. These values originate from ISO, ASTM and the like, or from own experiences. Besides providing the laboratories with a tool to check their momentary performance, the round robins are vary suitable for evaluating systematic developments on a long term basis. By splitting up the uncertainty according to methods, sample preparation/analysis, etc., knowledge can be extracted from the round robins for use in many other situations. (au)

  17. Precision and accuracy of multi-element analysis of aerosols using energy-dispersive x-ray fluorescence

    International Nuclear Information System (INIS)

    Adams, F.; Van Espen, P.

    1976-01-01

    Measurements have been carried out for the determination of the inherent errors of energy-dispersive X-ray fluorescence and for the evaluation of its precision and accuracy. The accuracy of the method is confirmed by independent determinations on the same samples using other analytical methods

  18. Precision and accuracy of blood glucose measurements using three different instruments.

    Science.gov (United States)

    Nowotny, B; Nowotny, P J; Strassburger, K; Roden, M

    2012-02-01

    Assessment of insulin sensitivity by dynamic metabolic tests such as the hyperinsulinemic euglycemic clamp critically relies on the reproducible and fast measurement of blood glucose concentrations. Although various instruments have been developed over the last decades, little is known as to the accuracy and comparability. We therefore compared the best new instrument with the former gold standard instruments to measure glucose concentrations in metabolic tests. Fasting blood samples of 15 diabetic and 10 healthy subjects were collected into sodium-fluoride tubes, spiked with glucose (0, 2.8, 6.9 and 11.1 mmol/l) and measured either as whole blood (range 3.3-26.3 mmol/l) or following centrifugation as plasma (range 3.9-32.0 mmol/l). Plasma samples were analyzed in the YSI-2300 STAT plus (YSI), EKF Biosen C-Line (EKF) and the reference method, Beckman Glucose analyzer-II (BMG), whole blood samples in EKF instruments with YSI as reference method. The average deviation of the EKF from the reference, BMG, was 3.0 ± 3.5% without any concentration-dependent variability. Glucose measurements by YSI were in good agreement with that by BMG (plasma) and EKF (plasma and whole blood) up to concentrations of 13.13 mmol/l (0.5 ± 3.7%), but deviation increased to -6.2 ± 3.8% at higher concentrations. Precision (n = 6) was ±2.2% (YSI), ±3.9% (EKF) and ±5.2% (BMG). The EKF instrument is comparable regarding accuracy and precision to the reference method BMG and can be used in metabolic tests, while the YSI showed a systematic shift at higher glucose concentrations. Based on these results we decided to replace BMG with EKF instrument in metabolic tests. © 2012 The Authors. Diabetic Medicine © 2012 Diabetes UK.

  19. Precision and accuracy of commonly used dental age estimation charts for the New Zealand population.

    Science.gov (United States)

    Baylis, Stephanie; Bassed, Richard

    2017-08-01

    Little research has been undertaken for the New Zealand population in the field of dental age estimation. This research to date indicates there are differences in dental developmental rates between the New Zealand population and other global population groups, and within the New Zealand population itself. Dental age estimation methods range from dental development charts to complex biometric analysis. Dental development charts are not the most accurate method of dental age estimation, but are time saving in their use. They are an excellent screening tool, particularly for post-mortem identification purposes, and for assessing variation from population norms in living individuals. The aim of this study was to test the precision and accuracy of three dental development charts (Schour and Massler, Blenkin and Taylor, and the London Atlas), used to estimate dental age of a sample of New Zealand juveniles between the ages of 5 and 18 years old (n=875). Percentage 'best fit' to correct age category and to expected chart stage were calculated to determine which chart was the most precise for the sample. Chronological ages were compared to estimated dental ages using a two-tailed paired t-test (Pcharts tested against the New Zealand population sample, the Blenkin and Taylor Australian charts performed best overall. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Accuracy and precision of estimating age of gray wolves by tooth wear

    Science.gov (United States)

    Gipson, P.S.; Ballard, W.B.; Nowak, R.M.; Mech, L.D.

    2000-01-01

    We evaluated the accuracy and precision of tooth wear for aging gray wolves (Canis lupus) from Alaska, Minnesota, and Ontario based on 47 known-age or known-minimum-age skulls. Estimates of age using tooth wear and a commercial cementum annuli-aging service were useful for wolves up to 14 years old. The precision of estimates from cementum annuli was greater than estimates from tooth wear, but tooth wear estimates are more applicable in the field. We tended to overestimate age by 1-2 years and occasionally by 3 or 4 years. The commercial service aged young wolves with cementum annuli to within ?? 1 year of actual age, but under estimated ages of wolves ???9 years old by 1-3 years. No differences were detected in tooth wear patterns for wild wolves from Alaska, Minnesota, and Ontario, nor between captive and wild wolves. Tooth wear was not appropriate for aging wolves with an underbite that prevented normal wear or severely broken and missing teeth.

  1. Temporal aggregation of migration counts can improve accuracy and precision of trends

    Directory of Open Access Journals (Sweden)

    Tara L. Crewe

    2016-12-01

    Full Text Available Temporal replicate counts are often aggregated to improve model fit by reducing zero-inflation and count variability, and in the case of migration counts collected hourly throughout a migration, allows one to ignore nonindependence. However, aggregation can represent a loss of potentially useful information on the hourly or seasonal distribution of counts, which might impact our ability to estimate reliable trends. We simulated 20-year hourly raptor migration count datasets with known rate of change to test the effect of aggregating hourly counts to daily or annual totals on our ability to recover known trend. We simulated data for three types of species, to test whether results varied with species abundance or migration strategy: a commonly detected species, e.g., Northern Harrier, Circus cyaneus; a rarely detected species, e.g., Peregrine Falcon, Falco peregrinus; and a species typically counted in large aggregations with overdispersed counts, e.g., Broad-winged Hawk, Buteo platypterus. We compared accuracy and precision of estimated trends across species and count types (hourly/daily/annual using hierarchical models that assumed a Poisson, negative binomial (NB or zero-inflated negative binomial (ZINB count distribution. We found little benefit of modeling zero-inflation or of modeling the hourly distribution of migration counts. For the rare species, trends analyzed using daily totals and an NB or ZINB data distribution resulted in a higher probability of detecting an accurate and precise trend. In contrast, trends of the common and overdispersed species benefited from aggregation to annual totals, and for the overdispersed species in particular, trends estimating using annual totals were more precise, and resulted in lower probabilities of estimating a trend (1 in the wrong direction, or (2 with credible intervals that excluded the true trend, as compared with hourly and daily counts.

  2. How training citizen scientists affects the accuracy and precision of phenological data

    Science.gov (United States)

    Feldman, Richard E.; Žemaitė, Irma; Miller-Rushing, Abraham J.

    2018-05-01

    Monitoring plant and animal phenology is a critical step to anticipating and predicting changes in species interactions and biodiversity. Because phenology necessarily involves frequent and repeated observations over time, citizen scientists have become a vital part of collecting phenological data. However, there is still concern over the accuracy and precision of citizen science data. It is possible that training citizen scientists can improve data quality though there are few comparisons of trained and untrained citizen scientists in the ability of each to accurately and precisely measure phenology. We assessed how three types of observers—experts, trained citizen scientists that make repeated observations, and untrained citizen scientists making once-per-year observations—differ in quantifying temporal change in flower and fruit abundance of American mountain ash trees (Sorbus americana Marsh.) and arthropods in Acadia National Park, Maine, USA. We found that trained more so than untrained citizen science observers over- or under-estimated abundances leading to precise but inaccurate characterizations of phenological patterns. Our results suggest a new type of bias induced by repeated observations: A type of learning takes place that reduces the independence of observations taken on different trees or different dates. Thus, in this and many other cases, having individuals make one-off observations of marked plants may produce data as good if not better than individuals making repeated observations. For citizen science programs related to phenology, our results underscore the importance of (a) attracting the most number of observers possible even if they only make one observation, (b) producing easy-to-use and informative data sheets, and (c) carefully planning effective training programs that are, perhaps, repeated at different points during the data collection period.

  3. Precision and accuracy of the NDF rumen degradability of hays measured by the Daisy fermenter

    Directory of Open Access Journals (Sweden)

    C. Zanfi

    2010-04-01

    Full Text Available An inventory of 162 hay samples from Austrian permanent grasslands was used to obtain information about the precision of the in vitro NDF degradability (NDFd measured by the Daisy fermenter and its accuracy to predict in situ NDFd. The within forage standard error of the in vitro NDFd triplicate, obtained in five consecutive incubations, was equal to 2.8%, while the effect of the four jar positions in the fermenter was not significant. The cutting frequency had a great impact on the in situ effective NDFd of hays, which ranged (P<0.01 from values of 32.9, 43.1 and 48.3% in hays obtained from 2, 3 and 4 cuts/season, respectively. The regression analysis between the in vitro and in situ NDFd values (measured at 48h and effective, k=3%/h allowed to obtain medium degrees of correlation (r2 = 0.69 – 0.71; P<0.01 and low levels of accuracy (RSE = 4.0 -4.6 %.

  4. Assessment of an alanine EPR dosimetry technique with enhanced precision and accuracy

    CERN Document Server

    Hayes, R B; Wieser, A; Romanyukha, A A; Hardy, B L; Barrus, J K

    2000-01-01

    Dose reconstruction in the course of a series of blind tests demonstrated that an accuracy of 10 mGy for low doses and 1% for high doses can be achieved using EPR spectroscopy. This was accomplished using a combination of methodologies including polynomial filtration of the EPR spectrum, dosimeter rotation during scanning, use of an EPR standard fixed into the resonator and subtraction of all nonradiogenic signals. Doses were reconstructed over the range of 0.01-1000 Gy using this compound spectral EPR analysis. This EPR technique, being equally applicable to fractionated doses (such as those delivered during multiple radiotherapy treatments), was verified to exhibit dose reciprocity. Irradiated alanine dosimeters which were stored exhibited compound spectral EPR signal fading of ca 3% over 9 months. All error estimates given in this paper are given at the 1 standard deviation level and unless otherwise specified do not account for uncertainties in source calibration.

  5. Assessment of an alanine EPR dosimetry technique with enhanced precision and accuracy

    International Nuclear Information System (INIS)

    Hayes, Robert B.; Haskell, E.H.; Wieser, Albrecht; Romanyukha, Alexander A.; Hardy, Byron L.; Barrus, Jeffrey K.

    2000-01-01

    Dose reconstruction in the course of a series of blind tests demonstrated that an accuracy of 10 mGy for low doses and 1% for high doses can be achieved using EPR spectroscopy. This was accomplished using a combination of methodologies including polynomial filtration of the EPR spectrum, dosimeter rotation during scanning, use of an EPR standard fixed into the resonator and subtraction of all nonradiogenic signals. Doses were reconstructed over the range of 0.01-1000 Gy using this compound spectral EPR analysis. This EPR technique, being equally applicable to fractionated doses (such as those delivered during multiple radiotherapy treatments), was verified to exhibit dose reciprocity. Irradiated alanine dosimeters which were stored exhibited compound spectral EPR signal fading of ca 3% over 9 months. All error estimates given in this paper are given at the 1 standard deviation level and unless otherwise specified do not account for uncertainties in source calibration

  6. Differential effects of visual feedback on subjective visual vertical accuracy and precision.

    Directory of Open Access Journals (Sweden)

    Daniel Bjasch

    Full Text Available The brain constructs an internal estimate of the gravitational vertical by integrating multiple sensory signals. In darkness, systematic head-roll dependent errors in verticality estimates, as measured by the subjective visual vertical (SVV, occur. We hypothesized that visual feedback after each trial results in increased accuracy, as physiological adjustment errors (A-/E-effect are likely based on central computational mechanisms and investigated whether such improvements were related to adaptational shifts of perceived vertical or to a higher cognitive strategy. We asked 12 healthy human subjects to adjust a luminous arrow to vertical in various head-roll positions (0 to 120deg right-ear down, 15deg steps. After each adjustment visual feedback was provided (lights on, display of previous adjustment and of an earth-vertical cross. Control trials consisted of SVV adjustments without feedback. At head-roll angles with the largest A-effect (90, 105, and 120deg, errors were reduced significantly (p0.05 influenced. In seven subjects an additional session with two consecutive blocks (first with, then without visual feedback was completed at 90, 105 and 120deg head-roll. In these positions the error-reduction by the previous visual feedback block remained significant over the consecutive 18-24 min (post-feedback block, i.e., was still significantly (p<0.002 different from the control trials. Eleven out of 12 subjects reported having consciously added a bias to their perceived vertical based on visual feedback in order to minimize errors. We conclude that improvements of SVV accuracy by visual feedback, which remained effective after removal of feedback for ≥18 min, rather resulted from a cognitive strategy than by adapting the internal estimate of the gravitational vertical. The mechanisms behind the SVV therefore, remained stable, which is also supported by the fact that SVV precision - depending mostly on otolith input - was not affected by visual

  7. Clinical decision support systems for improving diagnostic accuracy and achieving precision medicine.

    Science.gov (United States)

    Castaneda, Christian; Nalley, Kip; Mannion, Ciaran; Bhattacharyya, Pritish; Blake, Patrick; Pecora, Andrew; Goy, Andre; Suh, K Stephen

    2015-01-01

    As research laboratories and clinics collaborate to achieve precision medicine, both communities are required to understand mandated electronic health/medical record (EHR/EMR) initiatives that will be fully implemented in all clinics in the United States by 2015. Stakeholders will need to evaluate current record keeping practices and optimize and standardize methodologies to capture nearly all information in digital format. Collaborative efforts from academic and industry sectors are crucial to achieving higher efficacy in patient care while minimizing costs. Currently existing digitized data and information are present in multiple formats and are largely unstructured. In the absence of a universally accepted management system, departments and institutions continue to generate silos of information. As a result, invaluable and newly discovered knowledge is difficult to access. To accelerate biomedical research and reduce healthcare costs, clinical and bioinformatics systems must employ common data elements to create structured annotation forms enabling laboratories and clinics to capture sharable data in real time. Conversion of these datasets to knowable information should be a routine institutionalized process. New scientific knowledge and clinical discoveries can be shared via integrated knowledge environments defined by flexible data models and extensive use of standards, ontologies, vocabularies, and thesauri. In the clinical setting, aggregated knowledge must be displayed in user-friendly formats so that physicians, non-technical laboratory personnel, nurses, data/research coordinators, and end-users can enter data, access information, and understand the output. The effort to connect astronomical numbers of data points, including '-omics'-based molecular data, individual genome sequences, experimental data, patient clinical phenotypes, and follow-up data is a monumental task. Roadblocks to this vision of integration and interoperability include ethical, legal

  8. Probing the accuracy and precision of Hirshfeld atom refinement with HARt interfaced with Olex2

    Directory of Open Access Journals (Sweden)

    Malte Fugel

    2018-01-01

    Full Text Available Hirshfeld atom refinement (HAR is a novel X-ray structure refinement technique that employs aspherical atomic scattering factors obtained from stockholder partitioning of a theoretically determined tailor-made static electron density. HAR overcomes many of the known limitations of independent atom modelling (IAM, such as too short element–hydrogen distances, r(X—H, or too large atomic displacement parameters (ADPs. This study probes the accuracy and precision of anisotropic hydrogen and non-hydrogen ADPs and of r(X—H values obtained from HAR. These quantities are compared and found to agree with those obtained from (i accurate neutron diffraction data measured at the same temperatures as the X-ray data and (ii multipole modelling (MM, an established alternative method for interpreting X-ray diffraction data with the help of aspherical atomic scattering factors. Results are presented for three chemically different systems: the aromatic hydrocarbon rubrene (orthorhombic 5,6,11,12-tetraphenyltetracene, a co-crystal of zwitterionic betaine, imidazolium cations and picrate anions (BIPa, and the salt potassium hydrogen oxalate (KHOx. The non-hydrogen HAR-ADPs are as accurate and precise as the MM-ADPs. Both show excellent agreement with the neutron-based values and are superior to IAM-ADPs. The anisotropic hydrogen HAR-ADPs show a somewhat larger deviation from neutron-based values than the hydrogen SHADE-ADPs used in MM. Element–hydrogen bond lengths from HAR are in excellent agreement with those obtained from neutron diffraction experiments, although they are somewhat less precise. The residual density contour maps after HAR show fewer features than those after MM. Calculating the static electron density with the def2-TZVP basis set instead of the simpler def2-SVP one does not improve the refinement results significantly. All HARs were performed within the recently introduced HARt option implemented in the Olex2 program. They are easily

  9. Probing the accuracy and precision of Hirshfeld atom refinement with HARt interfaced with Olex2.

    Science.gov (United States)

    Fugel, Malte; Jayatilaka, Dylan; Hupf, Emanuel; Overgaard, Jacob; Hathwar, Venkatesha R; Macchi, Piero; Turner, Michael J; Howard, Judith A K; Dolomanov, Oleg V; Puschmann, Horst; Iversen, Bo B; Bürgi, Hans-Beat; Grabowsky, Simon

    2018-01-01

    Hirshfeld atom refinement (HAR) is a novel X-ray structure refinement technique that employs aspherical atomic scattering factors obtained from stockholder partitioning of a theoretically determined tailor-made static electron density. HAR overcomes many of the known limitations of independent atom modelling (IAM), such as too short element-hydrogen distances, r ( X -H), or too large atomic displacement parameters (ADPs). This study probes the accuracy and precision of anisotropic hydrogen and non-hydrogen ADPs and of r ( X -H) values obtained from HAR. These quantities are compared and found to agree with those obtained from (i) accurate neutron diffraction data measured at the same temperatures as the X-ray data and (ii) multipole modelling (MM), an established alternative method for interpreting X-ray diffraction data with the help of aspherical atomic scattering factors. Results are presented for three chemically different systems: the aromatic hydro-carbon rubrene (orthorhombic 5,6,11,12-tetra-phenyl-tetracene), a co-crystal of zwitterionic betaine, imidazolium cations and picrate anions (BIPa), and the salt potassium hydrogen oxalate (KHOx). The non-hydrogen HAR-ADPs are as accurate and precise as the MM-ADPs. Both show excellent agreement with the neutron-based values and are superior to IAM-ADPs. The anisotropic hydrogen HAR-ADPs show a somewhat larger deviation from neutron-based values than the hydrogen SHADE-ADPs used in MM. Element-hydrogen bond lengths from HAR are in excellent agreement with those obtained from neutron diffraction experiments, although they are somewhat less precise. The residual density contour maps after HAR show fewer features than those after MM. Calculating the static electron density with the def2-TZVP basis set instead of the simpler def2-SVP one does not improve the refinement results significantly. All HARs were performed within the recently introduced HARt option implemented in the Olex2 program. They are easily launched

  10. A Study of Equipment Accuracy and Test Precision in Dual Energy X-ray Absorptiometry

    International Nuclear Information System (INIS)

    Dong, Kyung Rae; Kim, Ho Sung; Jung, Woon Kwan

    2008-01-01

    Because there is a difference depending on the environment as for an inspection equipment the important part of bone density scan and the precision/accuracy of a tester, the management of quality must be made systematically. The equipment failure caused by overload effect due to the aged equipment and the increase of a patient was made frequently. Thus, the replacement of equipment and additional purchases of new bone density equipment caused a compatibility problem in tracking patients. This study wants to know whether the clinical changes of patient's bone density can be accurately and precisely reflected when used it compatibility like the existing equipment after equipment replacement and expansion. Two equipment of GE Lunar Prodigy Advance(P1 and P2) and the Phantom HOLOGIC Spine Road(HSP) were used to measure equipment precision. Each device scans 20 times so that precision data was acquired from the phantom(Group 1). The precision of a tester was measured by shooting twice the same patient, every 15 members from each of the target equipment in 120 women(average age 48.78, 20-60 years old)(Group 2). In addition, the measurement of the precision of a tester and the cross-calibration data were made by scanning 20 times in each of the equipment using HSP, based on the data obtained from the management of quality using phantom(ASP) every morning (Group 3). The same patient was shot only once in one equipment alternately to make the measurement of the precision of a tester and the cross-calibration data in 120 women(average age 48.78, 20-60 years old)(Group 4). It is steady equipment according to daily Q.C Data with 0.996 g/cm 2 , change value(%CV) 0.08. The meanSD and a %CV price are ALP in Group 1(P1 : , , P2 : , %CV=0.192). The mean±SD and a %CV price are P1 : 1.064±0.002 g/cm 2 , %CV=0.190 g/cm 2 , P2 : 1.061±0.003 g/cm 3 , %CV=0.163 in Group 2. The average error±2SD and %CV are P1 - (spine: 0.001±0.013 g/cm 2 , %CV=0.94, Femur: 0.001±0.019 g/cm 2 , %CV

  11. A Study of Equipment Accuracy and Test Precision in Dual Energy X-ray Absorptiometry

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Kyung Rae [Dept. of Radiological Technology, Gwangju Health College, Gwangju (Korea, Republic of); Kim, Ho Sung [Dept. of Nuclear Medicine, Asan Medical Center, Seoul (Korea, Republic of); Jung, Woon Kwan [Dept. of Nuclear Energy Technology, Chosun University, Gwangju (Korea, Republic of)

    2008-03-15

    Because there is a difference depending on the environment as for an inspection equipment the important part of bone density scan and the precision/accuracy of a tester, the management of quality must be made systematically. The equipment failure caused by overload effect due to the aged equipment and the increase of a patient was made frequently. Thus, the replacement of equipment and additional purchases of new bone density equipment caused a compatibility problem in tracking patients. This study wants to know whether the clinical changes of patient's bone density can be accurately and precisely reflected when used it compatibility like the existing equipment after equipment replacement and expansion. Two equipment of GE Lunar Prodigy Advance(P1 and P2) and the Phantom HOLOGIC Spine Road(HSP) were used to measure equipment precision. Each device scans 20 times so that precision data was acquired from the phantom(Group 1). The precision of a tester was measured by shooting twice the same patient, every 15 members from each of the target equipment in 120 women(average age 48.78, 20-60 years old)(Group 2). In addition, the measurement of the precision of a tester and the cross-calibration data were made by scanning 20 times in each of the equipment using HSP, based on the data obtained from the management of quality using phantom(ASP) every morning (Group 3). The same patient was shot only once in one equipment alternately to make the measurement of the precision of a tester and the cross-calibration data in 120 women(average age 48.78, 20-60 years old)(Group 4). It is steady equipment according to daily Q.C Data with 0.996 g/cm{sup 2}, change value(%CV) 0.08. The meanSD and a %CV price are ALP in Group 1(P1 : , , P2 : , %CV=0.192). The mean{+-}SD and a %CV price are P1 : 1.064{+-}0.002 g/cm{sup 2}, %CV=0.190 g/cm{sup 2}, P2 : 1.061{+-}0.003 g/cm{sup 3}, %CV=0.163 in Group 2. The average error{+-}2SD and %CV are P1 - (spine: 0.001{+-}0.013 g/cm{sup 2}, %CV=0

  12. Accuracy and precision of Legionella isolation by US laboratories in the ELITE program pilot study.

    Science.gov (United States)

    Lucas, Claressa E; Taylor, Thomas H; Fields, Barry S

    2011-10-01

    A pilot study for the Environmental Legionella Isolation Techniques Evaluation (ELITE) Program, a proficiency testing scheme for US laboratories that culture Legionella from environmental samples, was conducted September 1, 2008 through March 31, 2009. Participants (n=20) processed panels consisting of six sample types: pure and mixed positive, pure and mixed negative, pure and mixed variable. The majority (93%) of all samples (n=286) were correctly characterized, with 88.5% of samples positive for Legionella and 100% of negative samples identified correctly. Variable samples were incorrectly identified as negative in 36.9% of reports. For all samples reported positive (n=128), participants underestimated the cfu/ml by a mean of 1.25 logs with standard deviation of 0.78 logs, standard error of 0.07 logs, and a range of 3.57 logs compared to the CDC re-test value. Centering results around the interlaboratory mean yielded a standard deviation of 0.65 logs, standard error of 0.06 logs, and a range of 3.22 logs. Sampling protocol, treatment regimen, culture procedure, and laboratory experience did not significantly affect the accuracy or precision of reported concentrations. Qualitative and quantitative results from the ELITE pilot study were similar to reports from a corresponding proficiency testing scheme available in the European Union, indicating these results are probably valid for most environmental laboratories worldwide. The large enumeration error observed suggests that the need for remediation of a water system should not be determined solely by the concentration of Legionella observed in a sample since that value is likely to underestimate the true level of contamination. Published by Elsevier Ltd.

  13. L-shell x-ray fluorescence measurements of lead in bone: accuracy and precision

    International Nuclear Information System (INIS)

    Todd, Andrew C.; Carroll, Spencer; Khan, Fuad A.; Moshier, Erin L.; Geraghty, Ciaran; Tang, Shida; Parsons, Patrick J.

    2002-01-01

    This study aimed to quantify the accuracy and precision of a method for in vivo measurements of lead in bone using L-shell x-ray fluorescence (LXRF), the former via comparison with independent measurements of lead in bone obtained using electrothermal atomic absorption spectrometry (AAS) following acid digestion. Using LXRF, the lead content of adult human cadaver tibiae was measured, both as intact legs and as dissected tibiae with overlying tissue removed, the latter at several proximal-distal locations. After LXRF, each tibia was divided into nine cross-sectional segments, which were further separated into tibia core and surface samples for AAS measurement. The proximal-distal variability of AAS-measured core and surface tibia lead concentrations has been described elsewhere (the lead concentration was found to decrease towards both ends of the tibia). The subjects of this paper are the proximal-distal variability of the LXRF-measured lead concentrations, the measurement uncertainty and the statistical agreement between LXRF and AAS. There was no clear proximal-distal variability in the LXRF-measured concentrations; the degree of variability in actual tibia lead concentrations is far less than the LXRF measurement uncertainty. Measurement uncertainty was dominated by counting statistics and exceeded the estimate of lead concentration in most cases. The agreement between LXRF and AAS was reasonably good for bare bone measurements but poor for intact leg measurements. The variability of the LXRF measurements was large enough, for both bare bone and intact leg measurements, to yield grave concerns about the analytical use of the technique in vivo. (author)

  14. Evaluation of precision and accuracy of neutron activation analysis method of environmental samples analysis

    International Nuclear Information System (INIS)

    Wardani, Sri; Rina M, Th.; L, Dyah

    2000-01-01

    Evaluation of precision and accuracy of Neutron Activation Analysis (NAA) method used by P2TRR performed by analyzed the standard reference samples from the National Institute of Environmental Study of Japan (NIES-CRM No.10 (rice flour) and the National Bureau of USA (NBS-SRM 1573a (tomato leave) by NAA method. In analyze the environmental SRM No.10 by NAA method in qualitatively could identified multi elements of contents, namely: Br, Ca, Co, CI, Cs, Gd, I, K< La, Mg, Mn, Na, Pa, Sb, Sm, Sr, Ta, Th, and Zn (19 elements) for SRM 1573a; As, Br, Cr, CI, Ce, Co, Cs, Fe, Ga, Hg, K, Mn, Mg, Mo, Na, Ni, Pb, Rb, Sr, Se, Sc, Sb, Ti, and Zn, (25 elements) for CRM No.10a; Ag, As, Br, Cr, CI, Ce, Cd, Co, Cs, Eu, Fe, Ga, Hg, K, Mg, Mn, Mo, Na, Nb, Pb, Rb, Sb, Sc, Th, TI, and Zn, (26 elements) for CRM No. 10b; As, Br, Co, CI, Ce, Cd, Ga, Hg, K, Mn, Mg, Mo, Na, Nb, Pb, Rb, Sb, Se, TI, and Zn (20 elementary) for CRM No.10c. In the quantitatively analysis could determined only some element of sample contents, namely: As, Co, Cd, Mo, Mn, and Zn. From the result compared with NIES or NBS values attained with deviation of 3% ∼ 15%. Overall, the result shown that the method and facilities have a good capability, but the irradiation facility and the software of spectrometry gamma ray necessary to developing or seriously research perform

  15. 40 CFR 80.584 - What are the precision and accuracy criteria for approval of test methods for determining the...

    Science.gov (United States)

    2010-07-01

    ... criteria for approval of test methods for determining the sulfur content of motor vehicle diesel fuel, NRLM....584 What are the precision and accuracy criteria for approval of test methods for determining the... available gravimetric sulfur standard in the range of 1-10 ppm sulfur shall not differ from the accepted...

  16. Forecasting hypoxia in the Chesapeake Bay and Gulf of Mexico: model accuracy, precision, and sensitivity to ecosystem change

    International Nuclear Information System (INIS)

    Evans, Mary Anne; Scavia, Donald

    2011-01-01

    Increasing use of ecological models for management and policy requires robust evaluation of model precision, accuracy, and sensitivity to ecosystem change. We conducted such an evaluation of hypoxia models for the northern Gulf of Mexico and Chesapeake Bay using hindcasts of historical data, comparing several approaches to model calibration. For both systems we find that model sensitivity and precision can be optimized and model accuracy maintained within reasonable bounds by calibrating the model to relatively short, recent 3 year datasets. Model accuracy was higher for Chesapeake Bay than for the Gulf of Mexico, potentially indicating the greater importance of unmodeled processes in the latter system. Retrospective analyses demonstrate both directional and variable changes in sensitivity of hypoxia to nutrient loads.

  17. Precision and accuracy of the subjective haptic vertical in the roll plane

    Directory of Open Access Journals (Sweden)

    Bockisch Christopher J

    2010-07-01

    Full Text Available Abstract Background When roll-tilted, the subjective visual vertical (SVV deviates up to 40° from earth-vertical and trial-to-trial variability increases with head roll. Imperfections in the central processing of visual information were postulated to explain these roll-angle dependent errors. For experimental conditions devoid of visual input, e.g. adjustments of body posture or of an object along vertical in darkness, significantly smaller errors were noted. Whereas the accuracy of verticality adjustments seems to depend strongly on the paradigm, we hypothesize that the precision, i.e. the inverse of trial-to-trial variability, is less influenced by the experimental setup and mainly reflects properties of the otoliths. Here we measured the subjective haptic vertical (SHV and compared findings with previously reported SVV data. Twelve healthy right-handed human subjects (handedness assessed based on subjects' verbal report adjusted a rod with the right hand along perceived earth-vertical during static head roll-tilts (0-360°, steps of 20°. Results SHV adjustments showed a tendency for clockwise rod rotations to deviate counter-clockwise and for counter-clockwise rod rotations to deviate clockwise, indicating hysteresis. Clockwise rod rotations resulted in counter-clockwise shifts of perceived earth-vertical up to -11.7° and an average counter-clockwise SHV shift over all roll angles of -3.3° (± 11.0°; ± 1 StdDev. Counter-clockwise rod rotations yielded peak SHV deviations in clockwise direction of 8.9° and an average clockwise SHV shift over all roll angles of 1.8° (± 11.1°. Trial-to-trial variability was minimal in upright position, increased with increasing roll (peaking around 120-140° and decreased to intermediate values in upside-down orientation. Compared to SVV, SHV variability near upright and upside-down was non-significantly (p > 0.05 larger; both showed an m-shaped pattern of variability as a function of roll position

  18. EVALUATION OF RELATIVE GEOMETRIC ACCURACY OF TERRASAR-X BY PIXEL MATCHING METHODOLOGY

    Directory of Open Access Journals (Sweden)

    T. Nonaka

    2016-06-01

    Full Text Available Recently, high-resolution commercial SAR satellites with several meters of resolutions are widely utilized for various applications and disaster monitoring is one of the commonly applied areas. The information about the flooding situation and ground displacement was rapidly announced to the public after the Great East Japan Earthquake 2011. One of the studies reported the displacement in Tohoku region by the pixel matching methodology using both pre- and post- event TerraSAR-X data, and the validated accuracy was about 30 cm at the GEONET reference points. In order to discuss the spatial distribution of the displacement, we need to evaluate the relative accuracy of the displacement in addition to the absolute accuracy. In the previous studies, our study team evaluated the absolute 2D geo-location accuracy of the TerraSAR-X ortho-rectified EEC product for both flat and mountain areas. Therefore, the purpose of the current study was to evaluate the spatial and temporal relative geo-location accuracies of the product by considering the displacement of the fixed point as the relative geo-location accuracy. Firstly, by utilizing TerraSAR-X StripMap dataset, the pixel matching method for estimating the displacement with sub-pixel level was developed. Secondly, the validity of the method was confirmed by comparing with GEONET data. We confirmed that the accuracy of the displacement for X and Y direction was in agreement with the previous studies. Subsequently, the methodology was applied to 20 pairs of data set for areas of Tokyo Ota-ku and Kawasaki-shi, and the displacement of each pair was evaluated. It was revealed that the time series displacement rate had the seasonal trend and seemed to be related to atmospheric delay.

  19. Evaluation of Relative Geometric Accuracy of Terrasar-X by Pixel Matching Methodology

    Science.gov (United States)

    Nonaka, T.; Asaka, T.; Iwashita, K.

    2016-06-01

    Recently, high-resolution commercial SAR satellites with several meters of resolutions are widely utilized for various applications and disaster monitoring is one of the commonly applied areas. The information about the flooding situation and ground displacement was rapidly announced to the public after the Great East Japan Earthquake 2011. One of the studies reported the displacement in Tohoku region by the pixel matching methodology using both pre- and post- event TerraSAR-X data, and the validated accuracy was about 30 cm at the GEONET reference points. In order to discuss the spatial distribution of the displacement, we need to evaluate the relative accuracy of the displacement in addition to the absolute accuracy. In the previous studies, our study team evaluated the absolute 2D geo-location accuracy of the TerraSAR-X ortho-rectified EEC product for both flat and mountain areas. Therefore, the purpose of the current study was to evaluate the spatial and temporal relative geo-location accuracies of the product by considering the displacement of the fixed point as the relative geo-location accuracy. Firstly, by utilizing TerraSAR-X StripMap dataset, the pixel matching method for estimating the displacement with sub-pixel level was developed. Secondly, the validity of the method was confirmed by comparing with GEONET data. We confirmed that the accuracy of the displacement for X and Y direction was in agreement with the previous studies. Subsequently, the methodology was applied to 20 pairs of data set for areas of Tokyo Ota-ku and Kawasaki-shi, and the displacement of each pair was evaluated. It was revealed that the time series displacement rate had the seasonal trend and seemed to be related to atmospheric delay.

  20. Application of Calibration Curve, Accuracy and Precision Chart as Internal Quality Control at COD Testing in Wastewater

    Directory of Open Access Journals (Sweden)

    Uray Lusiana

    2012-06-01

    Full Text Available Quality assurance is one of the technical requirements that include in the quality management system based on SNI ISO/IEC 17025 : 2008. Quality assurance is all the process that planned and systematic activity that applied in analysis, so can give the confidence to the customer or data user. Quality assurance that is applied for COD testing in wastewater are calibration curve, accuracy and precision control chart. The purpose of calibration curve, accuracy and precision control chart applied was to control the data of COD testing so that guaranty the validity to report and to keep the consistence of testing result as statistic all the time. Calibration curve of COD testing have a coefficient correlation 0,99987. Accuracy control chart have limited line BTA = 104,95%, BPA = 102,97%, BIA = 100,98%, BTB = 93,03%, BPB = 95,02% and BIB = 97,0%. Accuracy data can be accepted if that data present between line of BPA and BPB (± 2 SD, data is warned if that data present between line BTA-BPA or BTB-BPB (± 2 SD and ± 3 SD, and data is outlier if that data present out of line BTA and BTB (± 3 SD. The precision data can accepted if that the RPD value is not more than 10 % of COD testing result.

  1. Evaluating perceptual integration: uniting response-time- and accuracy-based methodologies.

    Science.gov (United States)

    Eidels, Ami; Townsend, James T; Hughes, Howard C; Perry, Lacey A

    2015-02-01

    This investigation brings together a response-time system identification methodology (e.g., Townsend & Wenger Psychonomic Bulletin & Review 11, 391-418, 2004a) and an accuracy methodology, intended to assess models of integration across stimulus dimensions (features, modalities, etc.) that were proposed by Shaw and colleagues (e.g., Mulligan & Shaw Perception & Psychophysics 28, 471-478, 1980). The goal was to theoretically examine these separate strategies and to apply them conjointly to the same set of participants. The empirical phases were carried out within an extension of an established experimental design called the double factorial paradigm (e.g., Townsend & Nozawa Journal of Mathematical Psychology 39, 321-359, 1995). That paradigm, based on response times, permits assessments of architecture (parallel vs. serial processing), stopping rule (exhaustive vs. minimum time), and workload capacity, all within the same blocks of trials. The paradigm introduced by Shaw and colleagues uses a statistic formally analogous to that of the double factorial paradigm, but based on accuracy rather than response times. We demonstrate that the accuracy measure cannot discriminate between parallel and serial processing. Nonetheless, the class of models supported by the accuracy data possesses a suitable interpretation within the same set of models supported by the response-time data. The supported model, consistent across individuals, is parallel and has limited capacity, with the participants employing the appropriate stopping rule for the experimental setting.

  2. The migration of femoral components after total hip replacement surgery: accuracy and precision of software-aided measurements

    International Nuclear Information System (INIS)

    Decking, J.; Schuetz, U.; Decking, R.; Puhl, W.

    2003-01-01

    Objective: To assess the accuracy and precision of a software-aided system to measure migration of femoral components after total hip replacement (THR) on digitised radiographs. Design and patients: Subsidence and varus-valgus tilt of THR stems within the femur were measured on digitised anteroposterior pelvic radiographs. The measuring software (UMA, GEMED, Germany) relies on bony landmarks and comparability parameters of two consecutive radiographs. Its accuracy and precision were calculated by comparing it with the gold standard in migration measurements, radiostereometric analysis (RSA). Radiographs and corresponding RSA measurements were performed in 60 patients (38-69 years) following cementless THR surgery. Results and conclusions: The UMA software measured the subsidence of the stems with an accuracy of ±2.5 mm and varus-valgus tilt with an accuracy of ±1.8 (95% confidence interval). A good interobserver and intraobserver reliability was calculated with Cronbach's alpha ranging from 0.86 to 0.97. Measuring the subsidence of THR stems within the femur is an important parameter in the diagnosis of implant loosening. Software systems such as UMA improve the accuracy of migration measurements and are easy to use on routinely performed radiographs of operated hip joints. (orig.)

  3. Incorporating a Constrained Optimization Algorithm into Remote- Sensing/Precision Agriculture Methodology

    Science.gov (United States)

    Morgenthaler, George; Khatib, Nader; Kim, Byoungsoo

    with information to improve their crop's vigor has been a major topic of interest. With world population growing exponentially, arable land being consumed by urbanization, and an unfavorable farm economy, the efficiency of farming must increase to meet future food requirements and to make farming a sustainable occupation for the farmer. "Precision Agriculture" refers to a farming methodology that applies nutrients and moisture only where and when they are needed in the field. The goal is to increase farm revenue by increasing crop yield and decreasing applications of costly chemical and water treatments. In addition, this methodology will decrease the environmental costs of farming, i.e., reduce air, soil, and water pollution. Sensing/Precision Agriculture has not grown as rapidly as early advocates envisioned. Technology for a successful Remote Sensing/Precision Agriculture system is now available. Commercial satellite systems can image (multi-spectral) the Earth with a resolution of approximately 2.5 m. Variable precision dispensing systems using GPS are available and affordable. Crop models that predict yield as a function of soil, chemical, and irrigation parameter levels have been formulated. Personal computers and internet access are in place in most farm homes and can provide a mechanism to periodically disseminate, e.g. bi-weekly, advice on what quantities of water and chemicals are needed in individual regions of the field. What is missing is a model that fuses the disparate sources of information on the current states of the crop and soil, and the remaining resource levels available with the decisions farmers are required to make. This must be a product that is easy for the farmer to understand and to implement. A "Constrained Optimization Feed-back Control Model" to fill this void will be presented. The objective function of the model will be used to maximize the farmer's profit by increasing yields while decreasing environmental costs and decreasing

  4. Accuracy and Precision in Elemental Analysis of Environmental Samples using Inductively Coupled Plasma-Atomic Emission Spectrometry

    International Nuclear Information System (INIS)

    Quraishi, Shamsad Begum; Chung, Yong-Sam; Choi, Kwang Soon

    2005-01-01

    Inductively Coupled Plasma-Atomic Emission Spectrometry followed by micro-wave digestion have been performed on different environmental Certified Reference Materials (CRMs). Analytical results show that accuracy and precision in ICP-AES analysis were acceptable and satisfactory in case of soil and hair CRM samples. The relative error of most of the elements in these two CRMs is within 10% with few exceptions and coefficient of variation is also less than 10%. Z-score as an analytical performance was also within the acceptable range (±2). ICP-AES was found as an inadequate method for Air Filter CRM due to incomplete dissolution, low concentration of elements and very low mass of the sample. However, real air filter sample could have been analyzed with high accuracy and precision by increasing sample mass during collection. (author)

  5. Incorporating a constrained optimization algorithm into remote sensing/precision agriculture methodology

    Science.gov (United States)

    Moreenthaler, George W.; Khatib, Nader; Kim, Byoungsoo

    2003-08-01

    For two decades now, the use of Remote Sensing/Precision Agriculture to improve farm yields while reducing the use of polluting chemicals and the limited water supply has been a major goal. With world population growing exponentially, arable land being consumed by urbanization, and an unfavorable farm economy, farm efficiency must increase to meet future food requirements and to make farming a sustainable, profitable occupation. "Precision Agriculture" refers to a farming methodology that applies nutrients and moisture only where and when they are needed in the field. The real goal is to increase farm profitability by identifying the additional treatments of chemicals and water that increase revenues more than they increase costs and do no exceed pollution standards (constrained optimization). Even though the economic and environmental benefits appear to be great, Remote Sensing/Precision Agriculture has not grown as rapidly as early advocates envisioned. Technology for a successful Remote Sensing/Precision Agriculture system is now in place, but other needed factors have been missing. Commercial satellite systems can now image the Earth (multi-spectrally) with a resolution as fine as 2.5 m. Precision variable dispensing systems using GPS are now available and affordable. Crop models that predict yield as a function of soil, chemical, and irrigation parameter levels have been developed. Personal computers and internet access are now in place in most farm homes and can provide a mechanism for periodically disseminating advice on what quantities of water and chemicals are needed in specific regions of each field. Several processes have been selected that fuse the disparate sources of information on the current and historic states of the crop and soil, and the remaining resource levels available, with the critical decisions that farmers are required to make. These are done in a way that is easy for the farmer to understand and profitable to implement. A "Constrained

  6. Accuracy and precision of flash glucose monitoring sensors inserted into the abdomen and upper thigh compared with the upper arm.

    Science.gov (United States)

    Charleer, Sara; Mathieu, Chantal; Nobels, Frank; Gillard, Pieter

    2018-06-01

    Nowadays, most Belgian patients with type 1 diabetes use flash glucose monitoring (FreeStyle Libre [FSL]; Abbott Diabetes Care, Alameda, California) to check their glucose values, but some patients find the sensor on the upper arm too visible. The aim of the present study was to compare the accuracy and precision of FSL sensors when placed on different sites. A total of 23 adults with type 1 diabetes used three FSL sensors simultaneously for 14 days on the upper arm, abdomen and upper thigh. FSL measurements were compared with capillary blood glucose (BG) measurements obtained with a built-in FSL BG meter. The aggregated mean absolute relative difference was 11.8 ± 12.0%, 18.5 ± 18.4% and 12.3 ± 13.8% for the arm, abdomen (P = .002 vs arm) and thigh (P = .5 vs arm), respectively. Results of Clarke error grid analysis for the arm and thigh were similar (zone A: 84.9% vs 84.5%; P = .6), while less accuracy was seen for the abdomen (zone A: 69.4%; P = .01). Apart from the first day, the accuracy of FSL sensors on the arm and thigh was more stable across the 14-day wear duration than accuracy of sensors on the abdomen, which deteriorated mainly during week 2 (P < .0005). The aggregated precision absolute relative difference was markedly lower for the arm/thigh (10.9 ± 11.9%) compared with the arm/abdomen (20.9 ± 22.8%; P = .002). Our results indicate that the accuracy and precision of FSL sensors placed on the upper thigh are similar to the upper arm, whereas the abdomen performed unacceptably poorly. © 2018 John Wiley & Sons Ltd.

  7. On the accuracy and precision of numerical waveforms: effect of waveform extraction methodology

    Science.gov (United States)

    Chu, Tony; Fong, Heather; Kumar, Prayush; Pfeiffer, Harald P.; Boyle, Michael; Hemberger, Daniel A.; Kidder, Lawrence E.; Scheel, Mark A.; Szilagyi, Bela

    2016-08-01

    We present a new set of 95 numerical relativity simulations of non-precessing binary black holes (BBHs). The simulations sample comprehensively both black-hole spins up to spin magnitude of 0.9, and cover mass ratios 1-3. The simulations cover on average 24 inspiral orbits, plus merger and ringdown, with low initial orbital eccentricities e\\lt {10}-4. A subset of the simulations extends the coverage of non-spinning BBHs up to mass ratio q = 10. Gravitational waveforms at asymptotic infinity are computed with two independent techniques: extrapolation and Cauchy characteristic extraction. An error analysis based on noise-weighted inner products is performed. We find that numerical truncation error, error due to gravitational wave extraction, and errors due to the Fourier transformation of signals with finite length of the numerical waveforms are of similar magnitude, with gravitational wave extraction errors dominating at noise-weighted mismatches of ˜ 3× {10}-4. This set of waveforms will serve to validate and improve aligned-spin waveform models for gravitational wave science.

  8. FFT-BM, Code Accuracy Evaluations with the 1D Fast Fourier Transform (FFT) Methodology

    International Nuclear Information System (INIS)

    D'Auria, F.

    2004-01-01

    1 - Description of program or function: FFT-BM is an integrated version of the programs package performing code accuracy evaluations with the 1D Fast Fourier Transform (FFT) methodology. It contains two programs: - CASEM: Takes care of the complete manipulation of data in order to evaluate the quantities through which the FFT method quantifies the code accuracy. - AAWFTO completes the evaluation of the average accuracy (AA) and related weighted frequency (WF) values in order to obtain the AAtot and WFtot values characterising the global calculation performance. 2 - Methods: The Fast Fourier Transform, or FFT, which is based on the Fourier analysis method is an optimised method for calculating the amplitude Vs frequency, of functions or experimental or computed data. In order to apply this methodology, after selecting the parameters to be analyzed, it is necessary to choose the following parameters: - number of curves (exp + calc) to be analyzed; - number of time windows to be analyzed; - sampling frequency; - cut frequency; - time begin and time end of each time window. 3 - Restrictions on the complexity of the problem: Up to 30 curves (exp + calc) and 5 time windows may be analyzed

  9. Permitting of the accuracy in location of tumours and the accuracy in applying a precise dose covering in stereotactic gamma-knife treatments

    International Nuclear Information System (INIS)

    Ertl, A. G.

    1997-01-01

    The gamma-knife is a Co-60 irradiation device, permitting the location of a lesion with an accuracy of millimeters. Moreover, with the Gamma Knife it is possible to apply a precise dose covering the entire area inside the head. In order to visualize a lesion, we mostly have to resort to imaging techniques such as the MR tomography. The accuracy of locating the specific area for the stereotactic treatment was achieved with the help of a special screen plate which we designed ourselves. For determining the precise dose to be applied at the Gamma Knife, the central dose for all four collimator helmets as well as the dose distribution of the combined collimators had to be measured. In case of irradiations in prone position there may be considerable deviations compared to the dose-planning program; this we were able to demonstrate by a TLD array designed by ourselves. A more sophisticated evaluation of new dosimetry techniques - GafChromic films and BANG polymer gel - enabled us to investigate more complex irradiation patterns. (author)

  10. Accuracy and Precision of Plane Wave Vector Flow Imaging for Laminar and Complex Flow In Vivo

    DEFF Research Database (Denmark)

    Jensen, Jonas; Traberg, Marie Sand; Villagómez Hoyos, Carlos Armando

    2017-01-01

    In this study, a comparison between velocity fields for a plane wave 2-D vector flow imaging (VFI) method and a computational fluid dynamics (CFD) simulation is made. VFI estimates are obtained from the scan of a flow phantom, which mimics the complex flow conditions in the carotid artery....... Furthermore, the precision of the VFI method is investigated under laminar and complex flow conditions in vivo. The carotid bifurcation of a healthy volunteer was scanned using both fast plane wave ultrasound and magnetic resonance imaging (MRI). The acquired MRI geometry of the bifurcation was used...... difference within 15 %, however, it was 23 % in the external branch. For the in vivo scan, the precision in terms of mean standard deviation (SD) of estimates aligned to the cardiac cycle was highest in the center of the common carotid artery (SD 4.7◦ for angles) and lowest in the external branch and close...

  11. Improving the precision and accuracy of Mont Carlo simulation in positron emission tomography

    International Nuclear Information System (INIS)

    Picard, Y.; Thompson, C.J.; Marrett, S.

    1992-01-01

    This paper reports that most of the gamma-rays generated following positron annihilation in subjects undergoing PET studied never reach the detectors of a positron imaging device. Similarly, simulations of PET systems waste considerable time generating events which will never be detected. Simulation efficiency (in terms of detected photon pairs per CPU second) can be improved by generating only rays whose angular distribution gives them a reasonable chance of ultimate detection. For many events in which the original rays are directed generally towards the detectors, the precision of the final simulation can be improved by recycling them without reseeding the random number generator, giving them a second or greater chance of being detected. For simulation programs which cascade the simulation process into source, collimator, and detection phases, recycling can improve the precision of the simulation without requiring larger files of events from the source distribution simulation phase

  12. Maximizing precision and accuracy in quantitative autoradiographic determination of radiopharmaceutical distribution for dosimetry calculation

    International Nuclear Information System (INIS)

    Lear, J.L.; Mido, K.; Plotnick, J.; Muth, R.

    1986-01-01

    The authors developed operational equations which relate ranges of film darkening or optical density produced by exposures from autoradiograms to the ranges of radiopharmaceutical concentration contained in the autoradiograms. The equations were solved and used to define ranges of optical density which were optimal for precise determination of radiopharmaceutical concentration. The solutions indicated that in order to maximize precision in determination of tracer concentration, autoradiograms should be produced with images that are less dark than are typically considered pleasing to the eye. Based upon these observations, a solid state image analyzer was designed and developed for high spatial resolution, quantitative analysis of autoradiograms. The analyzer uses a linear array of charge-coupled devices (CCD's) which mechanically scans the autoradiograms. The images are digitalized into 512 x 512 or 1024 x 1024 pixels with 256 gray levels and directly mapped into memory. The system is therefore called a memory mapped, charge-coupled device scanner (MM-CCD). The images can be directly converted to represent tracer concentration or functional parameters and rapid region of interest analysis can be performed in single or multiple tracer studies. The performance of the system was compared to that of other commercially available image analyzers, rotating drum densitometers and video camera digitizers. Values of tracer concentration using the MM-CCD scanner were generally greater than twice as precise and accurate as from the other systems. 3 references, 4 figures, 3 tables

  13. High accuracy and precision micro injection moulding of thermoplastic elastomers micro ring production

    DEFF Research Database (Denmark)

    Calaon, Matteo; Tosello, Guido; Elsborg, René

    2016-01-01

    The mass-replication nature of the process calls for fast monitoring of process parameters and product geometrical characteristics. In this direction, the present study addresses the possibility to develop a micro manufacturing platform for micro assembly injection moulding with real-time process....../product monitoring and metrology. The study represent a new concept yet to be developed with great potential for high precision mass-manufacturing of highly functional 3D multi-material (i.e. including metal/soft polymer) micro components. The activities related to HINMICO project objectives proves the importance...

  14. Use of single-representative reverse-engineered surface-models for RSA does not affect measurement accuracy and precision.

    Science.gov (United States)

    Seehaus, Frank; Schwarze, Michael; Flörkemeier, Thilo; von Lewinski, Gabriela; Kaptein, Bart L; Jakubowitz, Eike; Hurschler, Christof

    2016-05-01

    Implant migration can be accurately quantified by model-based Roentgen stereophotogrammetric analysis (RSA), using an implant surface model to locate the implant relative to the bone. In a clinical situation, a single reverse engineering (RE) model for each implant type and size is used. It is unclear to what extent the accuracy and precision of migration measurement is affected by implant manufacturing variability unaccounted for by a single representative model. Individual RE models were generated for five short-stem hip implants of the same type and size. Two phantom analyses and one clinical analysis were performed: "Accuracy-matched models": one stem was assessed, and the results from the original RE model were compared with randomly selected models. "Accuracy-random model": each of the five stems was assessed and analyzed using one randomly selected RE model. "Precision-clinical setting": implant migration was calculated for eight patients, and all five available RE models were applied to each case. For the two phantom experiments, the 95%CI of the bias ranged from -0.28 mm to 0.30 mm for translation and -2.3° to 2.5° for rotation. In the clinical setting, precision is less than 0.5 mm and 1.2° for translation and rotation, respectively, except for rotations about the proximodistal axis (RSA can be achieved and are not biased by using a single representative RE model. At least for implants similar in shape to the investigated short-stem, individual models are not necessary. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:903-910, 2016. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  15. Very high precision and accuracy analysis of triple isotopic ratios of water. A critical instrumentation comparison study.

    Science.gov (United States)

    Gkinis, Vasileios; Holme, Christian; Morris, Valerie; Thayer, Abigail Grace; Vaughn, Bruce; Kjaer, Helle Astrid; Vallelonga, Paul; Simonsen, Marius; Jensen, Camilla Marie; Svensson, Anders; Maffrezzoli, Niccolo; Vinther, Bo; Dallmayr, Remi

    2017-04-01

    We present a performance comparison study between two state of the art Cavity Ring Down Spectrometers (Picarro L2310-i, L2140-i). The comparison took place during the Continuous Flow Analysis (CFA) campaign for the measurement of the Renland ice core, over a period of three months. Instant and complete vaporisation of the ice core melt stream, as well as of in-house water reference materials is achieved by accurate control of microflows of liquid into a homemade calibration system by following simple principles of the Hagen-Poiseuille law. Both instruments share the same vaporisation unit in a configuration that minimises sample preparation discrepancies between the two analyses. We describe our SMOW-SLAP calibration and measurement protocols for such a CFA application and present quality control metrics acquired during the full period of the campaign on a daily basis. The results indicate an unprecedented performance for all 3 isotopic ratios (δ2H, δ17O, δ18O ) in terms of precision, accuracy and resolution. We also comment on the precision and accuracy of the second order excess parameters of HD16O and H217O over H218O (Dxs, Δ17O ). To our knowledge these are the first reported CFA measurements at this level of precision and accuracy for all three isotopic ratios. Differences on the performance of the two instruments are carefully assessed during the measurement and reported here. Our quality control protocols extend to the area of low water mixing ratios, a regime in which often atmospheric vapour measurements take place and Cavity Ring Down Analysers show a poorer performance due to the lower signal to noise ratios. We address such issues and propose calibration protocols from which water vapour isotopic analyses can benefit from.

  16. Accuracy and Precision of Three-Dimensional Low Dose CT Compared to Standard RSA in Acetabular Cups: An Experimental Study.

    Science.gov (United States)

    Brodén, Cyrus; Olivecrona, Henrik; Maguire, Gerald Q; Noz, Marilyn E; Zeleznik, Michael P; Sköldenberg, Olof

    2016-01-01

    Background and Purpose. The gold standard for detection of implant wear and migration is currently radiostereometry (RSA). The purpose of this study is to compare a three-dimensional computed tomography technique (3D CT) to standard RSA as an alternative technique for measuring migration of acetabular cups in total hip arthroplasty. Materials and Methods. With tantalum beads, we marked one cemented and one uncemented cup and mounted these on a similarly marked pelvic model. A comparison was made between 3D CT and standard RSA for measuring migration. Twelve repeated stereoradiographs and CT scans with double examinations in each position and gradual migration of the implants were made. Precision and accuracy of the 3D CT were calculated. Results. The accuracy of the 3D CT ranged between 0.07 and 0.32 mm for translations and 0.21 and 0.82° for rotation. The precision ranged between 0.01 and 0.09 mm for translations and 0.06 and 0.29° for rotations, respectively. For standard RSA, the precision ranged between 0.04 and 0.09 mm for translations and 0.08 and 0.32° for rotations, respectively. There was no significant difference in precision between 3D CT and standard RSA. The effective radiation dose of the 3D CT method, comparable to RSA, was estimated to be 0.33 mSv. Interpretation. Low dose 3D CT is a comparable method to standard RSA in an experimental setting.

  17. Frescoed Vaults: Accuracy Controlled Simplified Methodology for Planar Development of Three-Dimensional Textured Models

    Directory of Open Access Journals (Sweden)

    Marco Giorgio Bevilacqua

    2016-03-01

    Full Text Available In the field of documentation and preservation of cultural heritage, there is keen interest in 3D metric viewing and rendering of architecture for both formal appearance and color. On the other hand, operative steps of restoration interventions still require full-scale, 2D metric surface representations. The transition from 3D to 2D representation, with the related geometric transformations, has not yet been fully formalized for planar development of frescoed vaults. Methodologies proposed so far on this subject provide transitioning from point cloud models to ideal mathematical surfaces and projecting textures using software tools. The methodology used for geometry and texture development in the present work does not require any dedicated software. The different processing steps can be individually checked for any error introduced, which can be then quantified. A direct accuracy check of the planar development of the frescoed surface has been carried out by qualified restorers, yielding a result of 3 mm. The proposed methodology, although requiring further studies to improve automation of the different processing steps, allowed extracting 2D drafts fully usable by operators restoring the vault frescoes.

  18. Multitemporal Accuracy and Precision Assessment of Unmanned Aerial System Photogrammetry for Slope-Scale Snow Depth Maps in Alpine Terrain

    Science.gov (United States)

    Adams, Marc S.; Bühler, Yves; Fromm, Reinhard

    2017-12-01

    Reliable and timely information on the spatio-temporal distribution of snow in alpine terrain plays an important role for a wide range of applications. Unmanned aerial system (UAS) photogrammetry is increasingly applied to cost-efficiently map the snow depth at very high resolution with flexible applicability. However, crucial questions regarding quality and repeatability of this technique are still under discussion. Here we present a multitemporal accuracy and precision assessment of UAS photogrammetry for snow depth mapping on the slope-scale. We mapped a 0.12 km2 large snow-covered study site, located in a high-alpine valley in Western Austria. 12 UAS flights were performed to acquire imagery at 0.05 m ground sampling distance in visible (VIS) and near-infrared (NIR) wavelengths with a modified commercial, off-the-shelf sensor mounted on a custom-built fixed-wing UAS. The imagery was processed with structure-from-motion photogrammetry software to generate orthophotos, digital surface models (DSMs) and snow depth maps (SDMs). Accuracy of DSMs and SDMs were assessed with terrestrial laser scanning and manual snow depth probing, respectively. The results show that under good illumination conditions (study site in full sunlight), the DSMs and SDMs were acquired with an accuracy of ≤ 0.25 and ≤ 0.29 m (both at 1σ), respectively. In case of poorly illuminated snow surfaces (study site shadowed), the NIR imagery provided higher accuracy (0.19 m; 0.23 m) than VIS imagery (0.49 m; 0.37 m). The precision of the UASSDMs was 0.04 m for a small, stable area and below 0.33 m for the whole study site (both at 1σ).

  19. SU-F-T-255: Accuracy and Precision of Dynamic Tracking Irradiation with VERO-4DRT System

    International Nuclear Information System (INIS)

    Hayashi, N; Takada, Y; Mizuno, T; Nakae, H; Murai, T

    2016-01-01

    Purpose: The VERO-4DRT system is able to provide dynamic tracking irradiation (DTI) for the target with respiratory motion. This technique requires enough commissioning for clinical implementation. The purpose of this study is to make sure the accuracy and precision of DTI using VERO- 4DRT through commissioning from fundamental evaluation to end-to-end test. Method: We evaluated several contents for DTI commissioning: the accuracy of absorption dose at isocenter in DTI, the field size and penumbra of DTI, the accuracy of 4D modeling in DTI. All evaluations were performed by respiratory motion phantom (Quasar phantom). These contents were compared the results between static irradiation and DTI. The shape of radiation field was set to square from 3 cm × 3 cm to 10 cm × 10 cm. The micro 3D chamber and Gafchromic EBT3 film were used for absorbed dose and relative dose distribution measurement, respectively. The sine and irregular shaped waves were used for demonstrative respiratory motion. The visicoil was implanted into the phantom for guidance of respiratory motion. The respiration patterns of frequency and motion amount were set to 10–15 BPM and 1–2 cm, respectively. Results: As the result of absorbed dose of DTI in comparison with static irradiation, the average dose error at isocenter was 0.5% even though various respiratory patterns were set on. As the result of relative dose distribution, the field size (set it on 50% dose line) was not significantly changed in all respiratory patterns. However, the penumbra was larger in greater respiratory motion (up to 4.1 mm). The 4D modeling coincidence between actual and created waves was within 1%. Conclusion: The DTI using VERO-4DRT can provide sufficient accuracy and precision in absorbed dose and distribution. However, the patientspecific quantitative internal margin corresponding respiratory motion should be taken into consideration with image guidance.

  20. SU-F-T-255: Accuracy and Precision of Dynamic Tracking Irradiation with VERO-4DRT System

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, N [Graduate school of Health Sciences, Fujita Health University, Tayoake, Aichi (Japan); Takada, Y; Mizuno, T; Nakae, H [Department of Radiology, Ogaki Tokushukai Hospital, Ogaki, Gifu (Japan); Murai, T [Department of Radiation Oncology, Nagoya City University, Nagoya, Aichi (Japan)

    2016-06-15

    Purpose: The VERO-4DRT system is able to provide dynamic tracking irradiation (DTI) for the target with respiratory motion. This technique requires enough commissioning for clinical implementation. The purpose of this study is to make sure the accuracy and precision of DTI using VERO- 4DRT through commissioning from fundamental evaluation to end-to-end test. Method: We evaluated several contents for DTI commissioning: the accuracy of absorption dose at isocenter in DTI, the field size and penumbra of DTI, the accuracy of 4D modeling in DTI. All evaluations were performed by respiratory motion phantom (Quasar phantom). These contents were compared the results between static irradiation and DTI. The shape of radiation field was set to square from 3 cm × 3 cm to 10 cm × 10 cm. The micro 3D chamber and Gafchromic EBT3 film were used for absorbed dose and relative dose distribution measurement, respectively. The sine and irregular shaped waves were used for demonstrative respiratory motion. The visicoil was implanted into the phantom for guidance of respiratory motion. The respiration patterns of frequency and motion amount were set to 10–15 BPM and 1–2 cm, respectively. Results: As the result of absorbed dose of DTI in comparison with static irradiation, the average dose error at isocenter was 0.5% even though various respiratory patterns were set on. As the result of relative dose distribution, the field size (set it on 50% dose line) was not significantly changed in all respiratory patterns. However, the penumbra was larger in greater respiratory motion (up to 4.1 mm). The 4D modeling coincidence between actual and created waves was within 1%. Conclusion: The DTI using VERO-4DRT can provide sufficient accuracy and precision in absorbed dose and distribution. However, the patientspecific quantitative internal margin corresponding respiratory motion should be taken into consideration with image guidance.

  1. Accuracy and Precision of Noninvasive Blood Pressure in Normo-, Hyper-, and Hypotensive Standing and Anesthetized Adult Horses.

    Science.gov (United States)

    Heliczer, N; Lorello, O; Casoni, D; Navas de Solis, C

    2016-05-01

    Blood pressure is relevant to the diagnosis and management of many medical, cardiovascular and critical diseases. The accuracy of many commonly used noninvasive blood pressure (NIBP) monitors and the accuracy of NIBP measurements in hypo- and hypertensive standing horses has not been determined. The objective of this study was to investigate the accuracy of an oscillometric BP monitor in standing horses before and during pharmacologically induced hyper- and hypotension and to compare results in standing and anesthetized horses. Eight standing mares from a research herd (SG) and eight anesthetized horses from a hospital population (AG). Prospective experimental and observational studies. Invasive blood pressure (IBP) and NIBP, corrected to heart level, were measured simultaneously. In the SG hyper- and hypotension were induced by administration of phenylephrine (3 μg/kg/min IV for 15 minutes) and acepromazine (0.05 mg/kg IV), respectively. In the AG NIBP and IBP were recorded during regular hospital procedures. There was a significant correlation between mean NIBP and IBP in standing (R = 0.88, P horses (R = 0.81, P horses, but in the SG significant correlation between NIBP and IBP was only detected for the normotensive phase. While the evaluated oscillometric BP device allowed estimation of BP and adequately differentiated marked trends, the accuracy and precision were low in standing horses. Copyright © 2016 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

  2. Quantification and visualization of carotid segmentation accuracy and precision using a 2D standardized carotid map

    International Nuclear Information System (INIS)

    Chiu, Bernard; Ukwatta, Eranga; Shavakh, Shadi; Fenster, Aaron

    2013-01-01

    This paper describes a framework for vascular image segmentation evaluation. Since the size of vessel wall and plaque burden is defined by the lumen and wall boundaries in vascular segmentation, these two boundaries should be considered as a pair in statistical evaluation of a segmentation algorithm. This work proposed statistical metrics to evaluate the difference of local vessel wall thickness (VWT) produced by manual and algorithm-based semi-automatic segmentation methods (ΔT) with the local segmentation standard deviation of the wall and lumen boundaries considered. ΔT was further approximately decomposed into the local wall and lumen boundary differences (ΔW and ΔL respectively) in order to provide information regarding which of the wall and lumen segmentation errors contribute more to the VWT difference. In this study, the lumen and wall boundaries in 3D carotid ultrasound images acquired for 21 subjects were each segmented five times manually and by a level-set segmentation algorithm. The (absolute) difference measures (i.e., ΔT, ΔW, ΔL and their absolute values) and the pooled local standard deviation of manually and algorithmically segmented wall and lumen boundaries were computed for each subject and represented in a 2D standardized map. The local accuracy and variability of the segmentation algorithm at each point can be quantified by the average of these metrics for the whole group of subjects and visualized on the 2D standardized map. Based on the results shown on the 2D standardized map, a variety of strategies, such as adding anchor points and adjusting weights of different forces in the algorithm, can be introduced to improve the accuracy and variability of the algorithm. (paper)

  3. New analytical methodology to reach the actinide determination accuracy ({+-} 2%) required by the OSMOSE program

    Energy Technology Data Exchange (ETDEWEB)

    Boyer-Deslys, V.; Combaluzier, T.; Dalier, V.; Martin, J.C.; Viallesoubranne, C. [DRCP/SE2A/LAMM, CEA/VALRHO - Marcoule, BP 17171, 30207 Bagnols-sur-Ceze (France); Crozet, M. [LEHA, CEA/VALRHO - Marcoule, BP 17171, 30207 Bagnols-sur-Ceze (France)

    2008-07-01

    This article describes the analytical procedure optimized by LAMM (Laboratory for Analysis and Materials Methodology) in order to characterize the actinide-doped pellets used in the Osmose (Oscillation in Minerve of isotopes in eupraxis spectra) program (developed for transmutation reactor physics). Osmose aims at providing precise experimental data (absorption cross sections) for heavy nuclides (atomic mass from 232 to 245). This procedure requires the use of the analytical equipment and expertise of the LAMM: TIMS (Thermal Ionization Mass Spectrometer), ICP (Inductively Coupled Plasma) QMS (Quadrupole Mass Spectrometer), SFMS (Sector Field Mass Spectrometer), AES (Atomic Emission Spectrometer), alpha spectrometry and photo-gravimetric analysis. These techniques have met all the specification requirements: extended uncertainties (k=2) below {+-} 2% on the uranium and dopant concentrations, the impurity concentration and the americium-241 concentration.

  4. Robotic-Arm Assisted Total Knee Arthroplasty Demonstrated Greater Accuracy and Precision to Plan Compared with Manual Techniques.

    Science.gov (United States)

    Hampp, Emily L; Chughtai, Morad; Scholl, Laura Y; Sodhi, Nipun; Bhowmik-Stoker, Manoshi; Jacofsky, David J; Mont, Michael A

    2018-05-01

    This study determined if robotic-arm assisted total knee arthroplasty (RATKA) allows for more accurate and precise bone cuts and component position to plan compared with manual total knee arthroplasty (MTKA). Specifically, we assessed the following: (1) final bone cuts, (2) final component position, and (3) a potential learning curve for RATKA. On six cadaver specimens (12 knees), a MTKA and RATKA were performed on the left and right knees, respectively. Bone-cut and final-component positioning errors relative to preoperative plans were compared. Median errors and standard deviations (SDs) in the sagittal, coronal, and axial planes were compared. Median values of the absolute deviation from plan defined the accuracy to plan. SDs described the precision to plan. RATKA bone cuts were as or more accurate to plan based on nominal median values in 11 out of 12 measurements. RATKA bone cuts were more precise to plan in 8 out of 12 measurements ( p  ≤ 0.05). RATKA final component positions were as or more accurate to plan based on median values in five out of five measurements. RATKA final component positions were more precise to plan in four out of five measurements ( p  ≤ 0.05). Stacked error results from all cuts and implant positions for each specimen in procedural order showed that RATKA error was less than MTKA error. Although this study analyzed a small number of cadaver specimens, there were clear differences that separated these two groups. When compared with MTKA, RATKA demonstrated more accurate and precise bone cuts and implant positioning to plan. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  5. Accuracy and precision of equine gait event detection during walking with limb and trunk mounted inertial sensors

    DEFF Research Database (Denmark)

    Olsen, Emil; Andersen, Pia Haubro; Pfau, Thilo

    2012-01-01

    The increased variations of temporal gait events when pathology is present are good candidate features for objective diagnostic tests. We hypothesised that the gait events hoof-on/off and stance can be detected accurately and precisely using features from trunk and distal limb-mounted Inertial....... Accuracy (bias) and precision (SD of bias) was calculated to compare force plate and IMU timings for gait events. Data were collected from seven horses. One hundred and twenty three (123) front limb steps were analysed; hoof-on was detected with a bias (SD) of -7 (23) ms, hoof-off with 0.7 (37) ms...... and front limb stance with -0.02 (37) ms. A total of 119 hind limb steps were analysed; hoof-on was found with a bias (SD) of -4 (25) ms, hoof-off with 6 (21) ms and hind limb stance with 0.2 (28) ms. IMUs mounted on the distal limbs and sacrum can detect gait events accurately and precisely....

  6. Video image analysis in the Australian meat industry - precision and accuracy of predicting lean meat yield in lamb carcasses.

    Science.gov (United States)

    Hopkins, D L; Safari, E; Thompson, J M; Smith, C R

    2004-06-01

    A wide selection of lamb types of mixed sex (ewes and wethers) were slaughtered at a commercial abattoir and during this process images of 360 carcasses were obtained online using the VIAScan® system developed by Meat and Livestock Australia. Soft tissue depth at the GR site (thickness of tissue over the 12th rib 110 mm from the midline) was measured by an abattoir employee using the AUS-MEAT sheep probe (PGR). Another measure of this thickness was taken in the chiller using a GR knife (NGR). Each carcass was subsequently broken down to a range of trimmed boneless retail cuts and the lean meat yield determined. The current industry model for predicting meat yield uses hot carcass weight (HCW) and tissue depth at the GR site. A low level of accuracy and precision was found when HCW and PGR were used to predict lean meat yield (R(2)=0.19, r.s.d.=2.80%), which could be improved markedly when PGR was replaced by NGR (R(2)=0.41, r.s.d.=2.39%). If the GR measures were replaced by 8 VIAScan® measures then greater prediction accuracy could be achieved (R(2)=0.52, r.s.d.=2.17%). A similar result was achieved when the model was based on principal components (PCs) computed from the 8 VIAScan® measures (R(2)=0.52, r.s.d.=2.17%). The use of PCs also improved the stability of the model compared to a regression model based on HCW and NGR. The transportability of the models was tested by randomly dividing the data set and comparing coefficients and the level of accuracy and precision. Those models based on PCs were superior to those based on regression. It is demonstrated that with the appropriate modeling the VIAScan® system offers a workable method for predicting lean meat yield automatically.

  7. Accuracy, Precision, Ease-Of-Use, and Cost of Methods to Test Ebola-Relevant Chlorine Solutions.

    Directory of Open Access Journals (Sweden)

    Emma Wells

    Full Text Available To prevent transmission in Ebola Virus Disease (EVD outbreaks, it is recommended to disinfect living things (hands and people with 0.05% chlorine solution and non-living things (surfaces, personal protective equipment, dead bodies with 0.5% chlorine solution. In the current West African EVD outbreak, these solutions (manufactured from calcium hypochlorite (HTH, sodium dichloroisocyanurate (NaDCC, and sodium hypochlorite (NaOCl have been widely used in both Ebola Treatment Unit and community settings. To ensure solution quality, testing is necessary, however test method appropriateness for these Ebola-relevant concentrations has not previously been evaluated. We identified fourteen commercially-available methods to test Ebola-relevant chlorine solution concentrations, including two titration methods, four DPD dilution methods, and six test strips. We assessed these methods by: 1 determining accuracy and precision by measuring in quintuplicate five different 0.05% and 0.5% chlorine solutions manufactured from NaDCC, HTH, and NaOCl; 2 conducting volunteer testing to assess ease-of-use; and, 3 determining costs. Accuracy was greatest in titration methods (reference-12.4% error compared to reference method, then DPD dilution methods (2.4-19% error, then test strips (5.2-48% error; precision followed this same trend. Two methods had an accuracy of <10% error across all five chlorine solutions with good precision: Hach digital titration for 0.05% and 0.5% solutions (recommended for contexts with trained personnel and financial resources, and Serim test strips for 0.05% solutions (recommended for contexts where rapid, inexpensive, and low-training burden testing is needed. Measurement error from test methods not including pH adjustment varied significantly across the five chlorine solutions, which had pH values 5-11. Volunteers found test strip easiest and titration hardest; costs per 100 tests were $14-37 for test strips and $33-609 for titration

  8. A comparison of accuracy and precision of 5 gait-event detection algorithms from motion capture in horses during over ground walk

    DEFF Research Database (Denmark)

    Olsen, Emil; Boye, Jenny Katrine; Pfau, Thilo

    2012-01-01

    and use robust and validated algorithms. It is the objective of this study to compare accuracy (bias) and precision (SD) for five published human and equine motion capture foot-on/off and stance phase detection algorithms during walk. Six horses were walked over 8 seamlessly embedded force plates...... of mass generally provides the most accurate and precise results in walk....

  9. Accuracy and precision of patient positioning for pelvic MR-only radiation therapy using digitally reconstructed radiographs

    Science.gov (United States)

    Kemppainen, R.; Vaara, T.; Joensuu, T.; Kiljunen, T.

    2018-03-01

    Background and Purpose. Magnetic resonance imaging (MRI) has in recent years emerged as an imaging modality to drive precise contouring of targets and organs at risk in external beam radiation therapy. Moreover, recent advances in MRI enable treatment of cancer without computed tomography (CT) simulation. A commercially available MR-only solution, MRCAT, offers a single-modality approach that provides density information for dose calculation and generation of positioning reference images. We evaluated the accuracy of patient positioning based on MRCAT digitally reconstructed radiographs (DRRs) by comparing to standard CT based workflow. Materials and Methods. Twenty consecutive prostate cancer patients being treated with external beam radiation therapy were included in the study. DRRs were generated for each patient based on the planning CT and MRCAT. The accuracy assessment was performed by manually registering the DRR images to planar kV setup images using bony landmarks. A Bayesian linear mixed effects model was used to separate systematic and random components (inter- and intra-observer variation) in the assessment. In addition, method agreement was assessed using a Bland-Altman analysis. Results. The systematic difference between MRCAT and CT based patient positioning, averaged over the study population, were found to be (mean [95% CI])  -0.49 [-0.85 to  -0.13] mm, 0.11 [-0.33 to  +0.57] mm and  -0.05 [-0.23 to  +0.36] mm in vertical, longitudinal and lateral directions, respectively. The increases in total random uncertainty were estimated to be below 0.5 mm for all directions, when using MR-only workflow instead of CT. Conclusions. The MRCAT pseudo-CT method provides clinically acceptable accuracy and precision for patient positioning for pelvic radiation therapy based on planar DRR images. Furthermore, due to the reduction of geometric uncertainty, compared to dual-modality workflow, the approach is likely to improve the total

  10. Precision and accuracy in CT attenuation measurement of vascular wall using region-of-interest supported by differentiation curve

    International Nuclear Information System (INIS)

    Suzuki, Shigeru; Kidouchi, Takashi; Kuwahara, Sadatoshi; Vembar, Mani; Takei, Ryoji; Yamamoto, Asako

    2012-01-01

    Objectives: To evaluate the precision and accuracy in CT attenuation measurement of vascular wall using region-of-interest (ROI) supported by differentiation curves. Study design: We used vascular models (actual attenuation value of the wall: 87 HU) with wall thicknesses of 1.5, 1.0, or 0.5 mm, filled with contrast material of 250, 348, or 436 HU. The nine vascular models were scanned with a 64-detector CT. The wall attenuation values were measured using three sizes (diameter: 0.5, 1.0, and 1.5 mm) of ROIs without differentiation curves. Sixteen measurements were repeated for each vascular model by each of two operators. Measurements supported by differentiation curves were also performed. We used analyses of variance with repeated measures for the measured attenuations for each size of the ROI. Results: Without differentiation curves, there were significant differences in the attenuation values of the wall among the three densities of contrast material, and the attenuation values tended to be overestimated more as the contrast material density increased. Operator dependencies were also found in measurements for 0.5- and 1.5-mm thickness models. With differentiation curves, measurements were not possible for 0.5- and 1.0-mm thickness models. Using differentiation curves for 1.5-mm thickness models with a ROI of 1.0- or 1.5-mm diameter, the wall attenuations were not affected by the contrast material densities and were operator independent, measuring between 75 and 103 HU. Conclusions: The use of differentiation curves can improve the precision and accuracy in wall attenuation measurement using a ROI technique, while measurements for walls of ≤1.0 mm thickness are difficult.

  11. Community-based Approaches to Improving Accuracy, Precision, and Reproducibility in U-Pb and U-Th Geochronology

    Science.gov (United States)

    McLean, N. M.; Condon, D. J.; Bowring, S. A.; Schoene, B.; Dutton, A.; Rubin, K. H.

    2015-12-01

    The last two decades have seen a grassroots effort by the international geochronology community to "calibrate Earth history through teamwork and cooperation," both as part of the EARTHTIME initiative and though several daughter projects with similar goals. Its mission originally challenged laboratories "to produce temporal constraints with uncertainties approaching 0.1% of the radioisotopic ages," but EARTHTIME has since exceeded its charge in many ways. Both the U-Pb and Ar-Ar chronometers first considered for high-precision timescale calibration now regularly produce dates at the sub-per mil level thanks to instrumentation, laboratory, and software advances. At the same time new isotope systems, including U-Th dating of carbonates, have developed comparable precision. But the larger, inter-related scientific challenges envisioned at EARTHTIME's inception remain - for instance, precisely calibrating the global geologic timescale, estimating rates of change around major climatic perturbations, and understanding evolutionary rates through time - and increasingly require that data from multiple geochronometers be combined. To solve these problems, the next two decades of uranium-daughter geochronology will require further advances in accuracy, precision, and reproducibility. The U-Th system has much in common with U-Pb, in that both parent and daughter isotopes are solids that can easily be weighed and dissolved in acid, and have well-characterized reference materials certified for isotopic composition and/or purity. For U-Pb, improving lab-to-lab reproducibility has entailed dissolving precisely weighed U and Pb metals of known purity and isotopic composition together to make gravimetric solutions, then using these to calibrate widely distributed tracers composed of artificial U and Pb isotopes. To mimic laboratory measurements, naturally occurring U and Pb isotopes were also mixed in proportions to mimic samples of three different ages, to be run as internal

  12. The Accuracy and Precision of Position and Orientation Tracking in the HTC Vive Virtual Reality System for Scientific Research

    Directory of Open Access Journals (Sweden)

    Diederick C. Niehorster

    2017-05-01

    Full Text Available The advent of inexpensive consumer virtual reality equipment enables many more researchers to study perception with naturally moving observers. One such system, the HTC Vive, offers a large field-of-view, high-resolution head mounted display together with a room-scale tracking system for less than a thousand U.S. dollars. If the position and orientation tracking of this system is of sufficient accuracy and precision, it could be suitable for much research that is currently done with far more expensive systems. Here we present a quantitative test of the HTC Vive’s position and orientation tracking as well as its end-to-end system latency. We report that while the precision of the Vive’s tracking measurements is high and its system latency (22 ms is low, its position and orientation measurements are provided in a coordinate system that is tilted with respect to the physical ground plane. Because large changes in offset were found whenever tracking was briefly lost, it cannot be corrected for with a one-time calibration procedure. We conclude that the varying offset between the virtual and the physical tracking space makes the HTC Vive at present unsuitable for scientific experiments that require accurate visual stimulation of self-motion through a virtual world. It may however be suited for other experiments that do not have this requirement.

  13. NiftyPET: a High-throughput Software Platform for High Quantitative Accuracy and Precision PET Imaging and Analysis.

    Science.gov (United States)

    Markiewicz, Pawel J; Ehrhardt, Matthias J; Erlandsson, Kjell; Noonan, Philip J; Barnes, Anna; Schott, Jonathan M; Atkinson, David; Arridge, Simon R; Hutton, Brian F; Ourselin, Sebastien

    2018-01-01

    We present a standalone, scalable and high-throughput software platform for PET image reconstruction and analysis. We focus on high fidelity modelling of the acquisition processes to provide high accuracy and precision quantitative imaging, especially for large axial field of view scanners. All the core routines are implemented using parallel computing available from within the Python package NiftyPET, enabling easy access, manipulation and visualisation of data at any processing stage. The pipeline of the platform starts from MR and raw PET input data and is divided into the following processing stages: (1) list-mode data processing; (2) accurate attenuation coefficient map generation; (3) detector normalisation; (4) exact forward and back projection between sinogram and image space; (5) estimation of reduced-variance random events; (6) high accuracy fully 3D estimation of scatter events; (7) voxel-based partial volume correction; (8) region- and voxel-level image analysis. We demonstrate the advantages of this platform using an amyloid brain scan where all the processing is executed from a single and uniform computational environment in Python. The high accuracy acquisition modelling is achieved through span-1 (no axial compression) ray tracing for true, random and scatter events. Furthermore, the platform offers uncertainty estimation of any image derived statistic to facilitate robust tracking of subtle physiological changes in longitudinal studies. The platform also supports the development of new reconstruction and analysis algorithms through restricting the axial field of view to any set of rings covering a region of interest and thus performing fully 3D reconstruction and corrections using real data significantly faster. All the software is available as open source with the accompanying wiki-page and test data.

  14. Single-frequency receivers as master permanent stations in GNSS networks: precision and accuracy of the positioning in mixed networks

    Science.gov (United States)

    Dabove, Paolo; Manzino, Ambrogio Maria

    2015-04-01

    The use of GPS/GNSS instruments is a common practice in the world at both a commercial and academic research level. Since last ten years, Continuous Operating Reference Stations (CORSs) networks were born in order to achieve the possibility to extend a precise positioning more than 15 km far from the master station. In this context, the Geomatics Research Group of DIATI at the Politecnico di Torino has carried out several experiments in order to evaluate the achievable precision obtainable with different GNSS receivers (geodetic and mass-market) and antennas if a CORSs network is considered. This work starts from the research above described, in particular focusing the attention on the usefulness of single frequency permanent stations in order to thicken the existing CORSs, especially for monitoring purposes. Two different types of CORSs network are available today in Italy: the first one is the so called "regional network" and the second one is the "national network", where the mean inter-station distances are about 25/30 and 50/70 km respectively. These distances are useful for many applications (e.g. mobile mapping) if geodetic instruments are considered but become less useful if mass-market instruments are used or if the inter-station distance between master and rover increases. In this context, some innovative GNSS networks were developed and tested, analyzing the performance of rover's positioning in terms of quality, accuracy and reliability both in real-time and post-processing approach. The use of single frequency GNSS receivers leads to have some limits, especially due to a limited baseline length, the possibility to obtain a correct fixing of the phase ambiguity for the network and to fix the phase ambiguity correctly also for the rover. These factors play a crucial role in order to reach a positioning with a good level of accuracy (as centimetric o better) in a short time and with an high reliability. The goal of this work is to investigate about the

  15. Strategy for high-accuracy-and-precision retrieval of atmospheric methane from the mid-infrared FTIR network

    Directory of Open Access Journals (Sweden)

    R. Sussmann

    2011-09-01

    Full Text Available We present a strategy (MIR-GBM v1.0 for the retrieval of column-averaged dry-air mole fractions of methane (XCH4 with a precision <0.3% (1-σ diurnal variation, 7-min integration and a seasonal bias <0.14% from mid-infrared ground-based solar FTIR measurements of the Network for the Detection of Atmospheric Composition Change (NDACC, comprising 22 FTIR stations. This makes NDACC methane data useful for satellite validation and for the inversion of regional-scale sources and sinks in addition to long-term trend analysis. Such retrievals complement the high accuracy and precision near-infrared observations of the younger Total Carbon Column Observing Network (TCCON with time series dating back 15 years or so before TCCON operations began.

    MIR-GBM v1.0 is using HITRAN 2000 (including the 2001 update release and 3 spectral micro windows (2613.70–2615.40 cm−1, 2835.50–2835.80 cm−1, 2921.00–2921.60 cm−1. A first-order Tikhonov constraint is applied to the state vector given in units of per cent of volume mixing ratio. It is tuned to achieve minimum diurnal variation without damping seasonality. Final quality selection of the retrievals uses a threshold for the goodness of fit (χ2 < 1 as well as for the ratio of root-mean-square spectral noise and information content (<0.15%. Column-averaged dry-air mole fractions are calculated using the retrieved methane profiles and four-times-daily pressure-temperature-humidity profiles from National Center for Environmental Prediction (NCEP interpolated to the time of measurement.

    MIR-GBM v1.0 is the optimum of 24 tested retrieval strategies (8 different spectral micro-window selections, 3 spectroscopic line lists: HITRAN 2000, 2004, 2008. Dominant errors of the non-optimum retrieval strategies are systematic HDO/H2O-CH4 interference errors leading to a seasonal bias up to ≈5%. Therefore interference

  16. A systematic review of the precision and accuracy of dose measurements in photon radiotherapy using polymer and Fricke MRI gel dosimetry

    International Nuclear Information System (INIS)

    MacDougall, N.D.; Pitchford, W.G.; Smith, M.A.

    2002-01-01

    The purpose of this work is to undertake a critical appraisal of the evidence in the published literature concerning the basic parameters of accuracy and precision associated with the use of Fricke and polymer gels (in conjunction with MR imaging) as radiation dosimeters in photon radiotherapy, condensing and analysing the body of published information (to the end of April 2002). A systematic review was undertaken addressing specific issues of precision and accuracy asking defined questions of the published literature. Accuracy and precision in relation to gel dosimetry were defined. Information was obtained from published, peer-reviewed journals. A defined search strategy utilizing MeSH headings and keywords, with extensive use of cross-referencing, identified 115 references dealing with gel dosimetry. Exclusion criteria were used to select only data from publications which would give unequivocal evidence. For accuracy, results had to be compared with an ionization chamber as gold standard and all gel samples had to be manufactured in the same batch. For precision, in addition to gels being from the same batch, samples must all have been irradiated at the same time and scanned simultaneously (or within a short time frame). Many results were found demonstrating 'dose mapping' examples using gels. However, there were very few publications containing firm evidence of precision and accuracy. There was no evidence which fulfilled our criteria about accuracy or precision using Fricke gels. For polymer gels only one paper was found for accuracy (4% (Low et al 1999 Med. Phys. 26 1542-51)) and precision (1.7% (Baldock et al 1998 Phys. Med. Biol. 43 695-702)); however, both were carried out at only one dose level. If the exclusion criteria were relaxed to include accuracy results comparing gel to a non gold standard dosimeter (e.g. TLD), results give a median accuracy of 10% (range 8-23.5%) for polymer gel (Cosgrove et al 2000 Phys. Med. Biol. 45 1195-210, De Deene et al

  17. Comparing the accuracy and precision of three techniques used for estimating missing landmarks when reconstructing fossil hominin crania.

    Science.gov (United States)

    Neeser, Rudolph; Ackermann, Rebecca Rogers; Gain, James

    2009-09-01

    Various methodological approaches have been used for reconstructing fossil hominin remains in order to increase sample sizes and to better understand morphological variation. Among these, morphometric quantitative techniques for reconstruction are increasingly common. Here we compare the accuracy of three approaches--mean substitution, thin plate splines, and multiple linear regression--for estimating missing landmarks of damaged fossil specimens. Comparisons are made varying the number of missing landmarks, sample sizes, and the reference species of the population used to perform the estimation. The testing is performed on landmark data from individuals of Homo sapiens, Pan troglodytes and Gorilla gorilla, and nine hominin fossil specimens. Results suggest that when a small, same-species fossil reference sample is available to guide reconstructions, thin plate spline approaches perform best. However, if no such sample is available (or if the species of the damaged individual is uncertain), estimates of missing morphology based on a single individual (or even a small sample) of close taxonomic affinity are less accurate than those based on a large sample of individuals drawn from more distantly related extant populations using a technique (such as a regression method) able to leverage the information (e.g., variation/covariation patterning) contained in this large sample. Thin plate splines also show an unexpectedly large amount of error in estimating landmarks, especially over large areas. Recommendations are made for estimating missing landmarks under various scenarios. Copyright 2009 Wiley-Liss, Inc.

  18. The impact of 3D volume of interest definition on accuracy and precision of activity estimation in quantitative SPECT and planar processing methods

    Science.gov (United States)

    He, Bin; Frey, Eric C.

    2010-06-01

    Accurate and precise estimation of organ activities is essential for treatment planning in targeted radionuclide therapy. We have previously evaluated the impact of processing methodology, statistical noise and variability in activity distribution and anatomy on the accuracy and precision of organ activity estimates obtained with quantitative SPECT (QSPECT) and planar (QPlanar) processing. Another important factor impacting the accuracy and precision of organ activity estimates is accuracy of and variability in the definition of organ regions of interest (ROI) or volumes of interest (VOI). The goal of this work was thus to systematically study the effects of VOI definition on the reliability of activity estimates. To this end, we performed Monte Carlo simulation studies using randomly perturbed and shifted VOIs to assess the impact on organ activity estimates. The 3D NCAT phantom was used with activities that modeled clinically observed 111In ibritumomab tiuxetan distributions. In order to study the errors resulting from misdefinitions due to manual segmentation errors, VOIs of the liver and left kidney were first manually defined. Each control point was then randomly perturbed to one of the nearest or next-nearest voxels in three ways: with no, inward or outward directional bias, resulting in random perturbation, erosion or dilation, respectively, of the VOIs. In order to study the errors resulting from the misregistration of VOIs, as would happen, e.g. in the case where the VOIs were defined using a misregistered anatomical image, the reconstructed SPECT images or projections were shifted by amounts ranging from -1 to 1 voxels in increments of with 0.1 voxels in both the transaxial and axial directions. The activity estimates from the shifted reconstructions or projections were compared to those from the originals, and average errors were computed for the QSPECT and QPlanar methods, respectively. For misregistration, errors in organ activity estimations were

  19. The impact of 3D volume of interest definition on accuracy and precision of activity estimation in quantitative SPECT and planar processing methods

    Energy Technology Data Exchange (ETDEWEB)

    He Bin [Division of Nuclear Medicine, Department of Radiology, New York Presbyterian Hospital-Weill Medical College of Cornell University, New York, NY 10021 (United States); Frey, Eric C, E-mail: bih2006@med.cornell.ed, E-mail: efrey1@jhmi.ed [Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD 21287-0859 (United States)

    2010-06-21

    Accurate and precise estimation of organ activities is essential for treatment planning in targeted radionuclide therapy. We have previously evaluated the impact of processing methodology, statistical noise and variability in activity distribution and anatomy on the accuracy and precision of organ activity estimates obtained with quantitative SPECT (QSPECT) and planar (QPlanar) processing. Another important factor impacting the accuracy and precision of organ activity estimates is accuracy of and variability in the definition of organ regions of interest (ROI) or volumes of interest (VOI). The goal of this work was thus to systematically study the effects of VOI definition on the reliability of activity estimates. To this end, we performed Monte Carlo simulation studies using randomly perturbed and shifted VOIs to assess the impact on organ activity estimates. The 3D NCAT phantom was used with activities that modeled clinically observed {sup 111}In ibritumomab tiuxetan distributions. In order to study the errors resulting from misdefinitions due to manual segmentation errors, VOIs of the liver and left kidney were first manually defined. Each control point was then randomly perturbed to one of the nearest or next-nearest voxels in three ways: with no, inward or outward directional bias, resulting in random perturbation, erosion or dilation, respectively, of the VOIs. In order to study the errors resulting from the misregistration of VOIs, as would happen, e.g. in the case where the VOIs were defined using a misregistered anatomical image, the reconstructed SPECT images or projections were shifted by amounts ranging from -1 to 1 voxels in increments of with 0.1 voxels in both the transaxial and axial directions. The activity estimates from the shifted reconstructions or projections were compared to those from the originals, and average errors were computed for the QSPECT and QPlanar methods, respectively. For misregistration, errors in organ activity estimations

  20. Error Estimation and Accuracy Improvements in Nodal Transport Methods; Estimacion de Errores y Aumento de la Precision en Metodos Nodales de Transporte

    Energy Technology Data Exchange (ETDEWEB)

    Zamonsky, O M [Comision Nacional de Energia Atomica, Centro Atomico Bariloche (Argentina)

    2000-07-01

    The accuracy of the solutions produced by the Discrete Ordinates neutron transport nodal methods is analyzed.The obtained new numerical methodologies increase the accuracy of the analyzed scheems and give a POSTERIORI error estimators. The accuracy improvement is obtained with new equations that make the numerical procedure free of truncation errors and proposing spatial reconstructions of the angular fluxes that are more accurate than those used until present. An a POSTERIORI error estimator is rigurously obtained for one dimensional systems that, in certain type of problems, allows to quantify the accuracy of the solutions. From comparisons with the one dimensional results, an a POSTERIORI error estimator is also obtained for multidimensional systems. LOCAL indicators, which quantify the spatial distribution of the errors, are obtained by the decomposition of the menctioned estimators. This makes the proposed methodology suitable to perform adaptive calculations. Some numerical examples are presented to validate the theoretical developements and to illustrate the ranges where the proposed approximations are valid.

  1. Sensor-Based Inspection of the Formation Accuracy in Ultra-Precision Grinding (UPG) of Aspheric Surface Considering the Chatter Vibration

    Science.gov (United States)

    Lei, Yao; Bai, Yue; Xu, Zhijun

    2018-06-01

    This paper proposes an experimental approach for monitoring and inspection of the formation accuracy in ultra-precision grinding (UPG) with respect to the chatter vibration. Two factors related to the grinding progress, the grinding speed of grinding wheel and spindle, and the oil pressure of the hydrostatic bearing are taken into account to determining the accuracy. In the meantime, a mathematical model of the radius deviation caused by the micro vibration is also established and applied in the experiments. The results show that the accuracy is sensitive to the vibration and the forming accuracy is much improved with proper processing parameters. It is found that the accuracy of aspheric surface can be less than 4 μm when the grinding speed is 1400 r/min and the wheel speed is 100 r/min with the oil pressure being 1.1 MPa.

  2. Sensor-Based Inspection of the Formation Accuracy in Ultra-Precision Grinding (UPG) of Aspheric Surface Considering the Chatter Vibration

    Science.gov (United States)

    Lei, Yao; Bai, Yue; Xu, Zhijun

    2018-03-01

    This paper proposes an experimental approach for monitoring and inspection of the formation accuracy in ultra-precision grinding (UPG) with respect to the chatter vibration. Two factors related to the grinding progress, the grinding speed of grinding wheel and spindle, and the oil pressure of the hydrostatic bearing are taken into account to determining the accuracy. In the meantime, a mathematical model of the radius deviation caused by the micro vibration is also established and applied in the experiments. The results show that the accuracy is sensitive to the vibration and the forming accuracy is much improved with proper processing parameters. It is found that the accuracy of aspheric surface can be less than 4 μm when the grinding speed is 1400 r/min and the wheel speed is 100 r/min with the oil pressure being 1.1 MPa.

  3. A simple and efficient methodology to improve geometric accuracy in gamma knife radiation surgery: implementation in multiple brain metastases.

    Science.gov (United States)

    Karaiskos, Pantelis; Moutsatsos, Argyris; Pappas, Eleftherios; Georgiou, Evangelos; Roussakis, Arkadios; Torrens, Michael; Seimenis, Ioannis

    2014-12-01

    To propose, verify, and implement a simple and efficient methodology for the improvement of total geometric accuracy in multiple brain metastases gamma knife (GK) radiation surgery. The proposed methodology exploits the directional dependence of magnetic resonance imaging (MRI)-related spatial distortions stemming from background field inhomogeneities, also known as sequence-dependent distortions, with respect to the read-gradient polarity during MRI acquisition. First, an extra MRI pulse sequence is acquired with the same imaging parameters as those used for routine patient imaging, aside from a reversal in the read-gradient polarity. Then, "average" image data are compounded from data acquired from the 2 MRI sequences and are used for treatment planning purposes. The method was applied and verified in a polymer gel phantom irradiated with multiple shots in an extended region of the GK stereotactic space. Its clinical impact in dose delivery accuracy was assessed in 15 patients with a total of 96 relatively small (series. Due to these uncertainties, a considerable underdosage (5%-32% of the prescription dose) was found in 33% of the studied targets. The proposed methodology is simple and straightforward in its implementation. Regarding multiple brain metastases applications, the suggested approach may substantially improve total GK dose delivery accuracy in smaller, outlying targets. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Development and application of a statistical methodology to evaluate the predictive accuracy of building energy baseline models

    Energy Technology Data Exchange (ETDEWEB)

    Granderson, Jessica [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). Energy Technologies Area Div.; Price, Phillip N. [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). Energy Technologies Area Div.

    2014-03-01

    This paper documents the development and application of a general statistical methodology to assess the accuracy of baseline energy models, focusing on its application to Measurement and Verification (M&V) of whole-­building energy savings. The methodology complements the principles addressed in resources such as ASHRAE Guideline 14 and the International Performance Measurement and Verification Protocol. It requires fitting a baseline model to data from a ``training period’’ and using the model to predict total electricity consumption during a subsequent ``prediction period.’’ We illustrate the methodology by evaluating five baseline models using data from 29 buildings. The training period and prediction period were varied, and model predictions of daily, weekly, and monthly energy consumption were compared to meter data to determine model accuracy. Several metrics were used to characterize the accuracy of the predictions, and in some cases the best-­performing model as judged by one metric was not the best performer when judged by another metric.

  5. Deformable Image Registration for Adaptive Radiation Therapy of Head and Neck Cancer: Accuracy and Precision in the Presence of Tumor Changes

    International Nuclear Information System (INIS)

    Mencarelli, Angelo; Kranen, Simon Robert van; Hamming-Vrieze, Olga; Beek, Suzanne van; Nico Rasch, Coenraad Robert; Herk, Marcel van; Sonke, Jan-Jakob

    2014-01-01

    Purpose: To compare deformable image registration (DIR) accuracy and precision for normal and tumor tissues in head and neck cancer patients during the course of radiation therapy (RT). Methods and Materials: Thirteen patients with oropharyngeal tumors, who underwent submucosal implantation of small gold markers (average 6, range 4-10) around the tumor and were treated with RT were retrospectively selected. Two observers identified 15 anatomical features (landmarks) representative of normal tissues in the planning computed tomography (pCT) scan and in weekly cone beam CTs (CBCTs). Gold markers were digitally removed after semiautomatic identification in pCTs and CBCTs. Subsequently, landmarks and gold markers on pCT were propagated to CBCTs, using a b-spline-based DIR and, for comparison, rigid registration (RR). To account for observer variability, the pair-wise difference analysis of variance method was applied. DIR accuracy (systematic error) and precision (random error) for landmarks and gold markers were quantified. Time trend of the precisions for RR and DIR over the weekly CBCTs were evaluated. Results: DIR accuracies were submillimeter and similar for normal and tumor tissue. DIR precision (1 SD) on the other hand was significantly different (P<.01), with 2.2 mm vector length in normal tissue versus 3.3 mm in tumor tissue. No significant time trend in DIR precision was found for normal tissue, whereas in tumor, DIR precision was significantly (P<.009) degraded during the course of treatment by 0.21 mm/week. Conclusions: DIR for tumor registration proved to be less precise than that for normal tissues due to limited contrast and complex non-elastic tumor response. Caution should therefore be exercised when applying DIR for tumor changes in adaptive procedures

  6. Methodological and empirical developments for the Ratcliff diffusion model of response times and accuracy

    NARCIS (Netherlands)

    Wagenmakers, E.-J.

    2009-01-01

    The Ratcliff diffusion model for simple two-choice decisions (e.g., Ratcliff, 1978; Ratcliff & McKoon, 2008) has two outstanding advantages. First, the model generally provides an excellent fit to the observed data (i.e., response accuracy and the shape of RT distributions, both for correct and

  7. Three-dimensional bone-implant movements in trochanteric hip fractures: Precision and accuracy of radiostereometric analysis in a phantom model.

    Science.gov (United States)

    Bojan, Alicja J; Bragdon, Charles; Jönsson, Anders; Ekholm, Carl; Kärrholm, Johan

    2015-05-01

    The accuracy and precision of RSA were evaluated in the experimental study of screw cut-out complication after fixation of trochanteric fractures. A plastic bone model of a two-part trochanteric fracture was constructed with a Gamma nail implant incorporating RSA markers. The femoral head fragment was attached to a separate rotational table and the femoral shaft was mounted on the micrometer. Three main motions were simulated: Femoral head translation and rotation along the axis of the lag screw and fracture fragment translation along anatomical axes. Accuracy and precision were determined according to ISO 16,087 and ASTM standard F2385-04. Translations along the lag screw axis were measured with a precision within  ±0.14 mm and an accuracy within ±0.03 mm. With simultaneous translations along all three anatomical axes, lowest precision was measured for the x-axis (±0.29, 0.07 mm, respectively), but improved when analyzed as a vector (±0.08, 0.03 mm). The precision and accuracy of femoral head rotations were within 0.5° and 0.18°, respectively. The resolution of the RSA method tested in this model was high, though it varied depending on the type of analyzed motion. This information is valuable when selecting and interpreting outcome parameters evaluating implant migration and osteosynthesis stability in future clinical RSA studies. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  8. Accuracy requirements on operational measurements in nuclear power plants with regard to balance methodology

    International Nuclear Information System (INIS)

    Holecek, C.

    1986-01-01

    Accurate in-service measurement is necessary for power balancing of nuclear power plants, i.e., the determination of fuel consumption, electric power generation, heat delivery and the degree of fuel power utilization. The only possible method of determining the input of total consumed energy from the fuel is the balance of the primary coolant circuit. This is because for the purposes of power balancing it is not possible to measure the amount of power generated from nuclear fuel. Relations are presented for the calculation of basic indices of the power balance. It is stated that for the purposes of power balancing and analyses the precision of measuring instrument at the input and output of balancing circuits is of primary importance, followed by the precision of measuring instruments inside balancing circuits and meters of auxiliary parameters. (Z.M.). 7 refs., 1 tab

  9. Routine lead isotope determinations using a lead-207-lead-204 double spike: a long-term assessment of analytical precision and accuracy

    International Nuclear Information System (INIS)

    Woodhead, J.D.; McCulloch, M.T.; Volker, F.

    1995-01-01

    Lead-isotope data obtained on a multicollector mass spectrometer over a four year period using a 207 Pb- 204 Pb double spike to correct for the effects of mass discrimination, are reported. Considerable improvements in both precision and accuracy over conventional correction procedures were noted, without recourse to rigorous loading or run conditions. An external precision in 206 Pb/ 204 Pb, 207 Pb/ 204 Pb and 208 Pb/ 204 Pb ratios ± 0.003, 0.003 and 0.01 (2 x standard deviation), respectively, is routinely obtainable independent of minor variations in loading and run parameters. (author)

  10. A Simple and Efficient Methodology To Improve Geometric Accuracy in Gamma Knife Radiation Surgery: Implementation in Multiple Brain Metastases

    Energy Technology Data Exchange (ETDEWEB)

    Karaiskos, Pantelis, E-mail: pkaraisk@med.uoa.gr [Medical Physics Laboratory, Medical School, University of Athens (Greece); Gamma Knife Department, Hygeia Hospital, Athens (Greece); Moutsatsos, Argyris; Pappas, Eleftherios; Georgiou, Evangelos [Medical Physics Laboratory, Medical School, University of Athens (Greece); Roussakis, Arkadios [CT and MRI Department, Hygeia Hospital, Athens (Greece); Torrens, Michael [Gamma Knife Department, Hygeia Hospital, Athens (Greece); Seimenis, Ioannis [Medical Physics Laboratory, Medical School, Democritus University of Thrace, Alexandroupolis (Greece)

    2014-12-01

    Purpose: To propose, verify, and implement a simple and efficient methodology for the improvement of total geometric accuracy in multiple brain metastases gamma knife (GK) radiation surgery. Methods and Materials: The proposed methodology exploits the directional dependence of magnetic resonance imaging (MRI)-related spatial distortions stemming from background field inhomogeneities, also known as sequence-dependent distortions, with respect to the read-gradient polarity during MRI acquisition. First, an extra MRI pulse sequence is acquired with the same imaging parameters as those used for routine patient imaging, aside from a reversal in the read-gradient polarity. Then, “average” image data are compounded from data acquired from the 2 MRI sequences and are used for treatment planning purposes. The method was applied and verified in a polymer gel phantom irradiated with multiple shots in an extended region of the GK stereotactic space. Its clinical impact in dose delivery accuracy was assessed in 15 patients with a total of 96 relatively small (<2 cm) metastases treated with GK radiation surgery. Results: Phantom study results showed that use of average MR images eliminates the effect of sequence-dependent distortions, leading to a total spatial uncertainty of less than 0.3 mm, attributed mainly to gradient nonlinearities. In brain metastases patients, non-eliminated sequence-dependent distortions lead to target localization uncertainties of up to 1.3 mm (mean: 0.51 ± 0.37 mm) with respect to the corresponding target locations in the “average” MRI series. Due to these uncertainties, a considerable underdosage (5%-32% of the prescription dose) was found in 33% of the studied targets. Conclusions: The proposed methodology is simple and straightforward in its implementation. Regarding multiple brain metastases applications, the suggested approach may substantially improve total GK dose delivery accuracy in smaller, outlying targets.

  11. The accuracy, precision and sustainability of different techniques for tablet subdivision: breaking by hand and the use of tablet splitters or a kitchen knife.

    Science.gov (United States)

    van Riet-Nales, Diana A; Doeve, Myrthe E; Nicia, Agnes E; Teerenstra, Steven; Notenboom, Kim; Hekster, Yechiel A; van den Bemt, Bart J F

    2014-05-15

    Tablets are frequently subdivided to lower the dose, to facilitate swallowing by e.g. children or older people or to save costs. Splitting devices are commonly used when hand breaking is difficult or painful. Three techniques for tablet subdivision were investigated: hand breaking, tablet splitter, kitchen knife. A best case drug (paracetamol), tablet (round, flat, uncoated, 500 mg) and operator (24-year student) were applied. Hundred tablets were subdivided by hand and by three devices of each of the following types: Fit & Healthy, Health Care Logistics, Lifetime, PillAid, PillTool, Pilomat tablet splitter; Blokker kitchen knife. The intra and inter device accuracy, precision and sustainability were investigated. The compliance to (adapted) regulatory requirements was investigated also. The accuracy and precision of hand broken tablets was 104/97% resp. 2.8/3.2% (one part per tablet considered; parts right/left side operator). The right/left accuracies of the splitting devices varied between 60 and 133%; the precisions 4.0 and 29.6%. The devices did not deteriorate over 100-fold use. Only hand broken tablets complied with all regulatory requirements. Health care professionals should realize that tablet splitting may result in inaccurate dosing. Authorities should undertake appropriate measures to assure good function of tablet splitters and, where feasible, to reduce the need for their use. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  12. Accuracy and precision of polyurethane dental arch models fabricated using a three-dimensional subtractive rapid prototyping method with an intraoral scanning technique.

    Science.gov (United States)

    Kim, Jae-Hong; Kim, Ki-Baek; Kim, Woong-Chul; Kim, Ji-Hwan; Kim, Hae-Young

    2014-03-01

    This study aimed to evaluate the accuracy and precision of polyurethane (PUT) dental arch models fabricated using a three-dimensional (3D) subtractive rapid prototyping (RP) method with an intraoral scanning technique by comparing linear measurements obtained from PUT models and conventional plaster models. Ten plaster models were duplicated using a selected standard master model and conventional impression, and 10 PUT models were duplicated using the 3D subtractive RP technique with an oral scanner. Six linear measurements were evaluated in terms of x, y, and z-axes using a non-contact white light scanner. Accuracy was assessed using mean differences between two measurements, and precision was examined using four quantitative methods and the Bland-Altman graphical method. Repeatability was evaluated in terms of intra-examiner variability, and reproducibility was assessed in terms of inter-examiner and inter-method variability. The mean difference between plaster models and PUT models ranged from 0.07 mm to 0.33 mm. Relative measurement errors ranged from 2.2% to 7.6% and intraclass correlation coefficients ranged from 0.93 to 0.96, when comparing plaster models and PUT models. The Bland-Altman plot showed good agreement. The accuracy and precision of PUT dental models for evaluating the performance of oral scanner and subtractive RP technology was acceptable. Because of the recent improvements in block material and computerized numeric control milling machines, the subtractive RP method may be a good choice for dental arch models.

  13. Accuracy and precision of four value-added blood glucose meters: the Abbott Optium, the DDI Prodigy, the HDI True Track, and the HypoGuard Assure Pro.

    Science.gov (United States)

    Sheffield, Catherine A; Kane, Michael P; Bakst, Gary; Busch, Robert S; Abelseth, Jill M; Hamilton, Robert A

    2009-09-01

    This study compared the accuracy and precision of four value-added glucose meters. Finger stick glucose measurements in diabetes patients were performed using the Abbott Diabetes Care (Alameda, CA) Optium, Diagnostic Devices, Inc. (Miami, FL) DDI Prodigy, Home Diagnostics, Inc. (Fort Lauderdale, FL) HDI True Track Smart System, and Arkray, USA (Minneapolis, MN) HypoGuard Assure Pro. Finger glucose measurements were compared with laboratory reference results. Accuracy was assessed by a Clarke error grid analysis (EGA), a Parkes EGA, and within 5%, 10%, 15%, and 20% of the laboratory value criteria (chi2 analysis). Meter precision was determined by calculating absolute mean differences in glucose values between duplicate samples (Kruskal-Wallis test). Finger sticks were obtained from 125 diabetes patients, of which 90.4% were Caucasian, 51.2% were female, 83.2% had type 2 diabetes, and average age of 59 years (SD 14 years). Mean venipuncture blood glucose was 151 mg/dL (SD +/-65 mg/dL; range, 58-474 mg/dL). Clinical accuracy by Clarke EGA was demonstrated in 94% of Optium, 82% of Prodigy, 61% of True Track, and 77% of the Assure Pro samples (P Abbott Optium was significantly more accurate than the other meter systems, whereas the HDI True Track was significantly less accurate and less precise compared to the other meter systems.

  14. The Influence of Measurement Methodology on the Accuracy of Electrical Waveform Distortion Analysis

    Science.gov (United States)

    Bartman, Jacek; Kwiatkowski, Bogdan

    2018-04-01

    The present paper covers a review of documents that specify measurement methods of voltage waveform distortion. It also presents measurement stages of waveform components that are uncommon in the classic fundamentals of electrotechnics and signal theory, including the creation process of groups and subgroups of harmonics and interharmonics. Moreover, the paper discusses selected distortion factors of periodic waveforms and presents analyses that compare the values of these distortion indices. The measurements were carried out in the cycle per cycle mode and the measurement methodology that was used complies with the IEC 61000-4-7 norm. The studies showed significant discrepancies between the values of analyzed parameters.

  15. Accuracy and precision of a custom camera-based system for 2D and 3D motion tracking during speech and nonspeech motor tasks

    Science.gov (United States)

    Feng, Yongqiang; Max, Ludo

    2014-01-01

    Purpose Studying normal or disordered motor control requires accurate motion tracking of the effectors (e.g., orofacial structures). The cost of electromagnetic, optoelectronic, and ultrasound systems is prohibitive for many laboratories, and limits clinical applications. For external movements (lips, jaw), video-based systems may be a viable alternative, provided that they offer high temporal resolution and sub-millimeter accuracy. Method We examined the accuracy and precision of 2D and 3D data recorded with a system that combines consumer-grade digital cameras capturing 60, 120, or 240 frames per second (fps), retro-reflective markers, commercially-available computer software (APAS, Ariel Dynamics), and a custom calibration device. Results Overall mean error (RMSE) across tests was 0.15 mm for static tracking and 0.26 mm for dynamic tracking, with corresponding precision (SD) values of 0.11 and 0.19 mm, respectively. The effect of frame rate varied across conditions, but, generally, accuracy was reduced at 240 fps. The effect of marker size (3 vs. 6 mm diameter) was negligible at all frame rates for both 2D and 3D data. Conclusion Motion tracking with consumer-grade digital cameras and the APAS software can achieve sub-millimeter accuracy at frame rates that are appropriate for kinematic analyses of lip/jaw movements for both research and clinical purposes. PMID:24686484

  16. [Feasibility and accuracy of ultrasound-guided methodology in the examination of lumbar spine facet joints].

    Science.gov (United States)

    Wen, Chuan-Bing; Li, Yong-Zhong; Tang, Qin-Qin; Sun, Lin; Xiao, Hong; Yang, Bang-Xiang; Song, Li; Liu, Hui

    2013-03-01

    To investigate the feasibility, accuracy of B ultrasound in the examination of joint space of lumbar spine facet joints compared with CT scan. Ten healthy adult volunteers were enrolled. The joint space of lumbar facet joints was measured by ultrasound. To identify the spinal levels, the posterior parasagittal sonograms were obtained at levels L1 to S1. The lumbar facet joints were delineated with the help of transverse sonograms at each level. Meanwhile, the lumbar facet joints were evaluated by spiral CT on the same plane, reformatted to 1-mm axial slices. A total of 88 lumbar facet joints from L1 to S1 were clearly visualized in the 10 volunteers. Both ultrasound and CT measurements showed the same average depth and lateral distance of lumbar facet joint space (P > 0.05). The lumbar facet joint space can be accurately demonstrated by ultrasound.

  17. A Novel Methodology to Validate the Accuracy of Extraoral Dental Scanners and Digital Articulation Systems.

    Science.gov (United States)

    Ellakwa, A; Elnajar, S; Littlefair, D; Sara, G

    2018-05-03

    The aim of the current study is to develop a novel method to investigate the accuracy of 3D scanners and digital articulation systems. An upper and a lower poured stone model were created by taking impression of fully dentate male (fifty years old) participant. Titanium spheres were added to the models to allow for an easily recognisable geometric shape for measurement after scanning and digital articulation. Measurements were obtained using a Coordinate Measuring Machine to record volumetric error, articulation error and clinical effect error. Three scanners were compared, including the Imetric 3D iScan d104i, Shining 3D AutoScan-DS100 and 3Shape D800, as well as their respective digital articulation software packages. Stoneglass Industries PDC digital articulation system was also applied to the Imetric scans for comparison with the CMM measurements. All the scans displayed low volumetric error (p⟩0.05), indicating that the scanners themselves had a minor contribution to the articulation and clinical effect errors. The PDC digital articulation system was found to deliver the lowest average errors, with good repeatability of results. The new measuring technique in the current study was able to assess the scanning and articulation accuracy of the four systems investigated. The PDC digital articulation system using Imetric scans was recommended as it displayed the lowest articulation error and clinical effect error with good repeatability. The low errors from the PDC system may have been due to its use of a 3D axis for alignment rather than the use of a best fit. Copyright© 2018 Dennis Barber Ltd.

  18. Evaluation of accuracy and precision of a smartphone based automated parasite egg counting system in comparison to the McMaster and Mini-FLOTAC methods.

    Science.gov (United States)

    Scare, J A; Slusarewicz, P; Noel, M L; Wielgus, K M; Nielsen, M K

    2017-11-30

    Fecal egg counts are emphasized for guiding equine helminth parasite control regimens due to the rise of anthelmintic resistance. This, however, poses further challenges, since egg counting results are prone to issues such as operator dependency, method variability, equipment requirements, and time commitment. The use of image analysis software for performing fecal egg counts is promoted in recent studies to reduce the operator dependency associated with manual counts. In an attempt to remove operator dependency associated with current methods, we developed a diagnostic system that utilizes a smartphone and employs image analysis to generate automated egg counts. The aims of this study were (1) to determine precision of the first smartphone prototype, the modified McMaster and ImageJ; (2) to determine precision, accuracy, sensitivity, and specificity of the second smartphone prototype, the modified McMaster, and Mini-FLOTAC techniques. Repeated counts on fecal samples naturally infected with equine strongyle eggs were performed using each technique to evaluate precision. Triplicate counts on 36 egg count negative samples and 36 samples spiked with strongyle eggs at 5, 50, 500, and 1000 eggs per gram were performed using a second smartphone system prototype, Mini-FLOTAC, and McMaster to determine technique accuracy. Precision across the techniques was evaluated using the coefficient of variation. In regards to the first aim of the study, the McMaster technique performed with significantly less variance than the first smartphone prototype and ImageJ (psmartphone and ImageJ performed with equal variance. In regards to the second aim of the study, the second smartphone system prototype had significantly better precision than the McMaster (psmartphone system were 64.51%, 21.67%, and 32.53%, respectively. The Mini-FLOTAC was significantly more accurate than the McMaster (psmartphone system (psmartphone and McMaster counts did not have statistically different accuracies

  19. Inactivation of the Medial-Prefrontal Cortex Impairs Interval Timing Precision, but Not Timing Accuracy or Scalar Timing in a Peak-Interval Procedure in Rats

    Directory of Open Access Journals (Sweden)

    Catalin V. Buhusi

    2018-06-01

    Full Text Available Motor sequence learning, planning and execution of goal-directed behaviors, and decision making rely on accurate time estimation and production of durations in the seconds-to-minutes range. The pathways involved in planning and execution of goal-directed behaviors include cortico-striato-thalamo-cortical circuitry modulated by dopaminergic inputs. A critical feature of interval timing is its scalar property, by which the precision of timing is proportional to the timed duration. We examined the role of medial prefrontal cortex (mPFC in timing by evaluating the effect of its reversible inactivation on timing accuracy, timing precision and scalar timing. Rats were trained to time two durations in a peak-interval (PI procedure. Reversible mPFC inactivation using GABA agonist muscimol resulted in decreased timing precision, with no effect on timing accuracy and scalar timing. These results are partly at odds with studies suggesting that ramping prefrontal activity is crucial to timing but closely match simulations with the Striatal Beat Frequency (SBF model proposing that timing is coded by the coincidental activation of striatal neurons by cortical inputs. Computer simulations indicate that in SBF, gradual inactivation of cortical inputs results in a gradual decrease in timing precision with preservation of timing accuracy and scalar timing. Further studies are needed to differentiate between timing models based on coincidence detection and timing models based on ramping mPFC activity, and clarify whether mPFC is specifically involved in timing, or more generally involved in attention, working memory, or response selection/inhibition.

  20. Study of the Effect of Modes of Electroerosion Treatment on the Microstructure and Accuracy of Precision Sizes of Small Parts

    Science.gov (United States)

    Korobova, N. V.; Aksenenko, A. Yu.; Bashevskaya, O. S.; Nikitin, A. A.

    2016-01-01

    Results of a study of the effect of the parameters of electroerosion treatment in a GF Agie Charmilles CUT 1000 OilTech wire-cutting bench on the size accuracy, the quality of the surface layer of cuts, and the microstructure of the surface of the treated parts are presented.

  1. Factors affecting in vivo measurement precision and accuracy of 109Cd K x-ray fluorescence measurements

    International Nuclear Information System (INIS)

    McNeill, F.E.; Stokes, L.; Kaye, W.E.

    1999-01-01

    109 Cd K x-ray fluorescence (XRF) measurement systems from two research centres were used to measure tibia lead content in a population (n=530) of young adults. The group mean bone lead contents (±SEM) determined by McMaster University (n=214) and the University of Maryland (n=316) were 2.80±0.51 and 2.33±0.50 μg Pb/(g bone mineral) respectively. The mean difference of 0.47±0.71 μg Pb/(g bone mineral) was not significant. There was no evidence of a systematic difference between measurements from the two systems. Measurement uncertainties for the young adults were poorer overall than uncertainties for a population of occupationally exposed men. This was because obese subjects and women were included in the study. Regressions of precision against body mass index (BMI, defined as weight/height 2 ) determined that uncertainties increased with BMI and were poorer for women than men. Measurement uncertainties (1σ) were >8 μg Pb/(g bone mineral) for women with a BMI > 0.004 kg cm -2 . Poor-precision data affected population estimates of bone lead content; an inverse correlation was found between precision and bone lead content. A small number (0.4%) of individual measurements with poor uncertainties were inaccurate to within the precision. It is suggested that obese subjects, whose BMI > 0.004 kg cm -2 , should be excluded from 109 Cd K XRF studies, as the measurement provides limited information and may be inaccurate. (author)

  2. Methodological quality of diagnostic accuracy studies on non-invasive coronary CT angiography: influence of QUADAS (Quality Assessment of Diagnostic Accuracy Studies included in systematic reviews) items on sensitivity and specificity

    Energy Technology Data Exchange (ETDEWEB)

    Schueler, Sabine; Walther, Stefan; Schuetz, Georg M. [Humboldt-Universitaet zu Berlin, Freie Universitaet Berlin, Charite Medical School, Department of Radiology, Berlin (Germany); Schlattmann, Peter [University Hospital of Friedrich Schiller University Jena, Department of Medical Statistics, Informatics, and Documentation, Jena (Germany); Dewey, Marc [Humboldt-Universitaet zu Berlin, Freie Universitaet Berlin, Charite Medical School, Department of Radiology, Berlin (Germany); Charite, Institut fuer Radiologie, Berlin (Germany)

    2013-06-15

    To evaluate the methodological quality of diagnostic accuracy studies on coronary computed tomography (CT) angiography using the QUADAS (Quality Assessment of Diagnostic Accuracy Studies included in systematic reviews) tool. Each QUADAS item was individually defined to adapt it to the special requirements of studies on coronary CT angiography. Two independent investigators analysed 118 studies using 12 QUADAS items. Meta-regression and pooled analyses were performed to identify possible effects of methodological quality items on estimates of diagnostic accuracy. The overall methodological quality of coronary CT studies was merely moderate. They fulfilled a median of 7.5 out of 12 items. Only 9 of the 118 studies fulfilled more than 75 % of possible QUADAS items. One QUADAS item (''Uninterpretable Results'') showed a significant influence (P = 0.02) on estimates of diagnostic accuracy with ''no fulfilment'' increasing specificity from 86 to 90 %. Furthermore, pooled analysis revealed that each QUADAS item that is not fulfilled has the potential to change estimates of diagnostic accuracy. The methodological quality of studies investigating the diagnostic accuracy of non-invasive coronary CT is only moderate and was found to affect the sensitivity and specificity. An improvement is highly desirable because good methodology is crucial for adequately assessing imaging technologies. (orig.)

  3. Methodological quality of diagnostic accuracy studies on non-invasive coronary CT angiography: influence of QUADAS (Quality Assessment of Diagnostic Accuracy Studies included in systematic reviews) items on sensitivity and specificity

    International Nuclear Information System (INIS)

    Schueler, Sabine; Walther, Stefan; Schuetz, Georg M.; Schlattmann, Peter; Dewey, Marc

    2013-01-01

    To evaluate the methodological quality of diagnostic accuracy studies on coronary computed tomography (CT) angiography using the QUADAS (Quality Assessment of Diagnostic Accuracy Studies included in systematic reviews) tool. Each QUADAS item was individually defined to adapt it to the special requirements of studies on coronary CT angiography. Two independent investigators analysed 118 studies using 12 QUADAS items. Meta-regression and pooled analyses were performed to identify possible effects of methodological quality items on estimates of diagnostic accuracy. The overall methodological quality of coronary CT studies was merely moderate. They fulfilled a median of 7.5 out of 12 items. Only 9 of the 118 studies fulfilled more than 75 % of possible QUADAS items. One QUADAS item (''Uninterpretable Results'') showed a significant influence (P = 0.02) on estimates of diagnostic accuracy with ''no fulfilment'' increasing specificity from 86 to 90 %. Furthermore, pooled analysis revealed that each QUADAS item that is not fulfilled has the potential to change estimates of diagnostic accuracy. The methodological quality of studies investigating the diagnostic accuracy of non-invasive coronary CT is only moderate and was found to affect the sensitivity and specificity. An improvement is highly desirable because good methodology is crucial for adequately assessing imaging technologies. (orig.)

  4. A geostatistical methodology to assess the accuracy of unsaturated flow models

    International Nuclear Information System (INIS)

    Smoot, J.L.; Williams, R.E.

    1996-04-01

    The Pacific Northwest National Laboratory spatiotemporal movement of water injected into (PNNL) has developed a Hydrologic unsaturated sediments at the Hanford Site in Evaluation Methodology (HEM) to assist the Washington State was used to develop a new U.S. Nuclear Regulatory Commission in method for evaluating mathematical model evaluating the potential that infiltrating meteoric predictions. Measured water content data were water will produce leachate at commercial low- interpolated geostatistically to a 16 x 16 x 36 level radioactive waste disposal sites. Two key grid at several time intervals. Then a issues are raised in the HEM: (1) evaluation of mathematical model was used to predict water mathematical models that predict facility content at the same grid locations at the selected performance, and (2) estimation of the times. Node-by-node comparison of the uncertainty associated with these mathematical mathematical model predictions with the model predictions. The technical objective of geostatistically interpolated values was this research is to adapt geostatistical tools conducted. The method facilitates a complete commonly used for model parameter estimation accounting and categorization of model error at to the problem of estimating the spatial every node. The comparison suggests that distribution of the dependent variable to be model results generally are within measurement calculated by the model. To fulfill this error. The worst model error occurs in silt objective, a database describing the lenses and is in excess of measurement error

  5. A geostatistical methodology to assess the accuracy of unsaturated flow models

    Energy Technology Data Exchange (ETDEWEB)

    Smoot, J.L.; Williams, R.E.

    1996-04-01

    The Pacific Northwest National Laboratory spatiotemporal movement of water injected into (PNNL) has developed a Hydrologic unsaturated sediments at the Hanford Site in Evaluation Methodology (HEM) to assist the Washington State was used to develop a new U.S. Nuclear Regulatory Commission in method for evaluating mathematical model evaluating the potential that infiltrating meteoric predictions. Measured water content data were water will produce leachate at commercial low- interpolated geostatistically to a 16 x 16 x 36 level radioactive waste disposal sites. Two key grid at several time intervals. Then a issues are raised in the HEM: (1) evaluation of mathematical model was used to predict water mathematical models that predict facility content at the same grid locations at the selected performance, and (2) estimation of the times. Node-by-node comparison of the uncertainty associated with these mathematical mathematical model predictions with the model predictions. The technical objective of geostatistically interpolated values was this research is to adapt geostatistical tools conducted. The method facilitates a complete commonly used for model parameter estimation accounting and categorization of model error at to the problem of estimating the spatial every node. The comparison suggests that distribution of the dependent variable to be model results generally are within measurement calculated by the model. To fulfill this error. The worst model error occurs in silt objective, a database describing the lenses and is in excess of measurement error.

  6. 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

  7. Rapid measurement of human milk macronutrients in the neonatal intensive care unit: accuracy and precision of fourier transform mid-infrared spectroscopy.

    Science.gov (United States)

    Smilowitz, Jennifer T; Gho, Deborah S; Mirmiran, Majid; German, J Bruce; Underwood, Mark A

    2014-05-01

    Although it is well established that human milk varies widely in macronutrient content, it remains common for human milk fortification for premature infants to be based on historic mean values. As a result, those caring for premature infants often underestimate protein intake. Rapid precise measurement of human milk protein, fat, and lactose to allow individualized fortification has been proposed for decades but remains elusive due to technical challenges. This study aimed to evaluate the accuracy and precision of a Fourier transform (FT) mid-infrared (IR) spectroscope in the neonatal intensive care unit to measure human milk fat, total protein, lactose, and calculated energy compared with standard chemical analyses. One hundred sixteen breast milk samples across lactation stages from women who delivered at term (n = 69) and preterm (n = 5) were analyzed with the FT mid-IR spectroscope and with standard chemical methods. Ten of the samples were tested in replicate using the FT mid-IR spectroscope to determine repeatability. The agreement between the FT mid-IR spectroscope analysis and reference methods was high for protein and fat and moderate for lactose and energy. The intra-assay coefficients of variation for all outcomes were less than 3%. The FT mid-IR spectroscope demonstrated high accuracy in measurement of total protein and fat of preterm and term milk with high precision.

  8. Accuracy and precision in the in vivo determination of bone minerals content using the attenuation of a continuous x-ray spectrum

    International Nuclear Information System (INIS)

    Jonson, R.; Roos, B.; Hansson, T.; Mattsson, S.

    1986-01-01

    An x-ray technique using a highly stabilized generator and a germanium detector for the in vivo determination of bone mineral content in the lumbar vertebra has been described previously from the authors laboratory. This technique estimates the bone mineral content in presence of fat and lean soft tissue in the path of the x-ray beam. The present investigation was undertaken in vitro to determine the accuracy, precision and long term reproducibility of the technique. The ash density of 12 human bone specimens was determined on the basis of ash weight and total volume measurements of each specimen. The result was compared with the measured bone mineral content. The deviation between the result of the attenuation measurements and the weight/volume measurements was (4 +/- 0.9%). The precision of the method as measured in vitro has been determined to be between +/- 1.6% (high bone mineral content) and +/- 2.6% (low bone mineral content) by repeated measurements on a new type of bone mineral phantom. The results show that the technique described gives an accuracy and a precision which is of the same order of magnitude as the technique using dual photon energy absorptiometry

  9. Technical Report on the Modification of 3-Dimensional Non-contact Human Body Laser Scanner for the Measurement of Anthropometric Dimensions: Verification of its Accuracy and Precision.

    Science.gov (United States)

    Jafari Roodbandi, Akram Sadat; Naderi, Hamid; Hashenmi-Nejad, Naser; Choobineh, Alireza; Baneshi, Mohammad Reza; Feyzi, Vafa

    2017-01-01

    Introduction: Three-dimensional (3D) scanners are widely used in medicine. One of the applications of 3D scanners is the acquisition of anthropometric dimensions for ergonomics and the creation of an anthropometry data bank. The aim of this study was to evaluate the precision and accuracy of a modified 3D scanner fabricated in this study. Methods: In this work, a 3D scan of the human body was obtained using DAVID Laser Scanner software and its calibration background, a linear low-power laser, and one advanced webcam. After the 3D scans were imported to the Geomagic software, 10 anthropometric dimensions of 10 subjects were obtained. The measurements of the 3D scanner were compared to the measurements of the same dimensions by a direct anthropometric method. The precision and accuracy of the measurements of the 3D scanner were then evaluated. The obtained data were analyzed using an independent sample t test with the SPSS software. Results: The minimum and maximum measurement differences from three consecutive scans by the 3D scanner were 0.03 mm and 18 mm, respectively. The differences between the measurements by the direct anthropometry method and the 3D scanner were not statistically significant. Therefore, the accuracy of the 3D scanner is acceptable. Conclusion: Future studies will need to focus on the improvement of the scanning speed and the quality of the scanned image.

  10. Dose evaluation using multiple-aliquot quartz OSL: Test of methods and a new protocol for improved accuracy and precision

    DEFF Research Database (Denmark)

    Jain, M.; Bøtter-Jensen, L.; Singhvi, A.K.

    2003-01-01

    -dose-dependent sensitivity changes during the pre-heat, and fundamental variability in the shapes of quartz OSL (blue-green or blue-light stimulated luminescence) decay forms. A new protocol using a combination of 'elevated temperature IR cleaning' (ETIR) and 'component-specific dose normalisation' (CSDN) has been developed....... CSDN accounts for variability in the OSL decay forms and absorbs such sensitivity changes. A combination of ETIR and CSDN protocol increased palaeodose precision from +/-100% to +/-4% in quartz separates from the fluvially transported sands in the Thar desert. A comparison with palaeodose estimates...

  11. Effects of disease severity distribution on the performance of quantitative diagnostic methods and proposal of a novel 'V-plot' methodology to display accuracy values.

    Science.gov (United States)

    Petraco, Ricardo; Dehbi, Hakim-Moulay; Howard, James P; Shun-Shin, Matthew J; Sen, Sayan; Nijjer, Sukhjinder S; Mayet, Jamil; Davies, Justin E; Francis, Darrel P

    2018-01-01

    Diagnostic accuracy is widely accepted by researchers and clinicians as an optimal expression of a test's performance. The aim of this study was to evaluate the effects of disease severity distribution on values of diagnostic accuracy as well as propose a sample-independent methodology to calculate and display accuracy of diagnostic tests. We evaluated the diagnostic relationship between two hypothetical methods to measure serum cholesterol (Chol rapid and Chol gold ) by generating samples with statistical software and (1) keeping the numerical relationship between methods unchanged and (2) changing the distribution of cholesterol values. Metrics of categorical agreement were calculated (accuracy, sensitivity and specificity). Finally, a novel methodology to display and calculate accuracy values was presented (the V-plot of accuracies). No single value of diagnostic accuracy can be used to describe the relationship between tests, as accuracy is a metric heavily affected by the underlying sample distribution. Our novel proposed methodology, the V-plot of accuracies, can be used as a sample-independent measure of a test performance against a reference gold standard.

  12. Effects of disease severity distribution on the performance of quantitative diagnostic methods and proposal of a novel ‘V-plot’ methodology to display accuracy values

    Science.gov (United States)

    Dehbi, Hakim-Moulay; Howard, James P; Shun-Shin, Matthew J; Sen, Sayan; Nijjer, Sukhjinder S; Mayet, Jamil; Davies, Justin E; Francis, Darrel P

    2018-01-01

    Background Diagnostic accuracy is widely accepted by researchers and clinicians as an optimal expression of a test’s performance. The aim of this study was to evaluate the effects of disease severity distribution on values of diagnostic accuracy as well as propose a sample-independent methodology to calculate and display accuracy of diagnostic tests. Methods and findings We evaluated the diagnostic relationship between two hypothetical methods to measure serum cholesterol (Cholrapid and Cholgold) by generating samples with statistical software and (1) keeping the numerical relationship between methods unchanged and (2) changing the distribution of cholesterol values. Metrics of categorical agreement were calculated (accuracy, sensitivity and specificity). Finally, a novel methodology to display and calculate accuracy values was presented (the V-plot of accuracies). Conclusion No single value of diagnostic accuracy can be used to describe the relationship between tests, as accuracy is a metric heavily affected by the underlying sample distribution. Our novel proposed methodology, the V-plot of accuracies, can be used as a sample-independent measure of a test performance against a reference gold standard. PMID:29387424

  13. Experimental assessment of precision and accuracy of radiostereometric analysis for the determination of polyethylene wear in a total hip replacement model.

    Science.gov (United States)

    Bragdon, Charles R; Malchau, Henrik; Yuan, Xunhua; Perinchief, Rebecca; Kärrholm, Johan; Börlin, Niclas; Estok, Daniel M; Harris, William H

    2002-07-01

    The purpose of this study was to develop and test a phantom model based on actual total hip replacement (THR) components to simulate the true penetration of the femoral head resulting from polyethylene wear. This model was used to study both the accuracy and the precision of radiostereometric analysis, RSA, in measuring wear. We also used this model to evaluate optimum tantalum bead configuration for this particular cup design when used in a clinical setting. A physical model of a total hip replacement (a phantom) was constructed which could simulate progressive, three-dimensional (3-D) penetration of the femoral head into the polyethylene component of a THR. Using a coordinate measuring machine (CMM) the positioning of the femoral head using the phantom was measured to be accurate to within 7 microm. The accuracy and precision of an RSA analysis system was determined from five repeat examinations of the phantom using various experimental set-ups of the phantom. The accuracy of the radiostereometric analysis, in this optimal experimental set-up studied was 33 microm for the medial direction, 22 microm for the superior direction, 86 microm for the posterior direction and 55 microm for the resultant 3-D vector length. The corresponding precision at the 95% confidence interval of the test results for repositioning the phantom five times, measured 8.4 microm for the medial direction, 5.5 microm for the superior direction, 16.0 microm for the posterior direction, and 13.5 microm for the resultant 3-D vector length. This in vitro model is proposed as a useful tool for developing a standard for the evaluation of radiostereometric and other radiographic methods used to measure in vivo wear.

  14. Precision and accuracy of manual water-level measurements taken in the Yucca Mountain area, Nye County, Nevada, 1988--1990

    International Nuclear Information System (INIS)

    Boucher, M.S.

    1994-01-01

    Water-level measurements have been made in deep boreholes in the Yucca Mountain area, Nye County, Nevada, since 1983 in support of the US Department of Energy's Yucca Mountain Project, which is an evaluation of the area to determine its suit-ability as a potential storage area for high-level nuclear waste. Water-level measurements were taken either manually, using various water-level measuring equipment such as steel tapes, or they were taken continuously, using automated data recorders and pressure transducers. This report presents precision range and accuracy data established for manual water-level measurements taken in the Yucca Mountain area, 1988--90

  15. Vegetation index cartography as a methodology complement to the terroir zoning for its use in precision viticulture

    Directory of Open Access Journals (Sweden)

    Alvaro Martínez

    2017-09-01

    Full Text Available Aim: Precision Viticulture (PV is a form of vineyard management based on tools that offer winegrowers georeferenced information of each vineyard, mainly sector mapping (sub-areas differentiated by characteristics capable of influencing vineyard usage. This provides knowledge of the variations in these sectors and PV treats each one of them in an independent and optimised manner. This allows, amongst many other possibilities, to monitor fruit ripening with the objective of performing site-specific harvest based on the characteristics of each given sector. Local variations in soil features and natural environmental factors, such as climate, lithology, geomorphology and soil, determine the units that drive or limit PV. Methods and results: In this paper, multispectral images are used. These have been obtained between veraison and harvest in three different years in order to calculate four vegetation indexes (VI that have been used since the end of the last century to delimit homogenous sectors in vineyards: the Normalized Difference Vegetation Index (NDVI, the Improved Soil Adjusted Vegetation Index (MSAVI, the Simple Ratio Index (SR and the Modified Simple Ratio Index (MSR. Mapping of these VI has allowed to relate their distribution with natural environmental factors with the objective of valuing their use in the discrimination of homogenous sectors as a complement and/or alternative to traditional methodologies to terroir zoning. Results show that, in the area studied, the vineyards planted in alluvial soil and conglomerated zones, over dominant fine-loamy, mixed, mesic, Calcixerollic Xerochrept soil series, at elevations between 519 and 604 m, oriented east and on slopes less than 5º present higher values for all four indexes throughout the three years of study. Conclusions: It is precisely these environmental elements (lithology, soil, elevation, orientation and slope and many soil features that must be relatively uniform in order to make an

  16. Assessing the Accuracy of Generalized Inferences From Comparison Group Studies Using a Within-Study Comparison Approach: The Methodology.

    Science.gov (United States)

    Jaciw, Andrew P

    2016-06-01

    Various studies have examined bias in impact estimates from comparison group studies (CGSs) of job training programs, and in education, where results are benchmarked against experimental results. Such within-study comparison (WSC) approaches investigate levels of bias in CGS-based impact estimates, as well as the success of various design and analytic strategies for reducing bias. This article reviews past literature and summarizes conditions under which CGSs replicate experimental benchmark results. It extends the framework to, and develops the methodology for, situations where results from CGSs are generalized to untreated inference populations. Past research is summarized; methods are developed to examine bias in program impact estimates based on cross-site comparisons in a multisite trial that are evaluated against site-specific experimental benchmarks. Students in Grades K-3 in 79 schools in Tennessee; students in Grades 4-8 in 82 schools in Alabama. Grades K-3 Stanford Achievement Test (SAT) in reading and math scores; Grades 4-8 SAT10 reading scores. Past studies show that bias in CGS-based estimates can be limited through strong design, with local matching, and appropriate analysis involving pretest covariates and variables that represent selection processes. Extension of the methodology to investigate accuracy of generalized estimates from CGSs shows bias from confounders and effect moderators. CGS results, when extrapolated to untreated inference populations, may be biased due to variation in outcomes and impact. Accounting for effects of confounders or moderators may reduce bias. © The Author(s) 2016.

  17. TOWARD HIGH-PRECISION SEISMIC STUDIES OF WHITE DWARF STARS: PARAMETRIZATION OF THE CORE AND TESTS OF ACCURACY

    Energy Technology Data Exchange (ETDEWEB)

    Giammichele, N.; Fontaine, G.; Brassard, P. [Département de Physique, Université de Montréal, Montréal, QC H3C 3J7 (Canada); Charpinet, S. [Université de Toulouse, UPS-OMP, IRAP, Toulouse F-31400 (France)

    2017-01-10

    We present a prescription for parametrizing the chemical profile in the core of white dwarfs in light of the recent discovery that pulsation modes may sometimes be deeply confined in some cool pulsating white dwarfs. Such modes may be used as unique probes of the complicated chemical stratification that results from several processes that occurred in previous evolutionary phases of intermediate-mass stars. This effort is part of our ongoing quest for more credible and realistic seismic models of white dwarfs using static, parametrized equilibrium structures. Inspired by successful techniques developed in design optimization fields (such as aerodynamics), we exploit Akima splines for the tracing of the chemical profile of oxygen (carbon) in the core of a white dwarf model. A series of tests are then presented to better seize the precision and significance of the results that can be obtained in an asteroseismological context. We also show that the new parametrization passes an essential basic test, as it successfully reproduces the chemical stratification of a full evolutionary model.

  18. TOWARD HIGH-PRECISION SEISMIC STUDIES OF WHITE DWARF STARS: PARAMETRIZATION OF THE CORE AND TESTS OF ACCURACY

    International Nuclear Information System (INIS)

    Giammichele, N.; Fontaine, G.; Brassard, P.; Charpinet, S.

    2017-01-01

    We present a prescription for parametrizing the chemical profile in the core of white dwarfs in light of the recent discovery that pulsation modes may sometimes be deeply confined in some cool pulsating white dwarfs. Such modes may be used as unique probes of the complicated chemical stratification that results from several processes that occurred in previous evolutionary phases of intermediate-mass stars. This effort is part of our ongoing quest for more credible and realistic seismic models of white dwarfs using static, parametrized equilibrium structures. Inspired by successful techniques developed in design optimization fields (such as aerodynamics), we exploit Akima splines for the tracing of the chemical profile of oxygen (carbon) in the core of a white dwarf model. A series of tests are then presented to better seize the precision and significance of the results that can be obtained in an asteroseismological context. We also show that the new parametrization passes an essential basic test, as it successfully reproduces the chemical stratification of a full evolutionary model.

  19. Improved Precision and Accuracy of Quantification of Rare Earth Element Abundances via Medium-Resolution LA-ICP-MS.

    Science.gov (United States)

    Funderburg, Rebecca; Arevalo, Ricardo; Locmelis, Marek; Adachi, Tomoko

    2017-11-01

    Laser ablation ICP-MS enables streamlined, high-sensitivity measurements of rare earth element (REE) abundances in geological materials. However, many REE isotope mass stations are plagued by isobaric interferences, particularly from diatomic oxides and argides. In this study, we compare REE abundances quantitated from mass spectra collected with low-resolution (m/Δm = 300 at 5% peak height) and medium-resolution (m/Δm = 2500) mass discrimination. A wide array of geological samples was analyzed, including USGS and NIST glasses ranging from mafic to felsic in composition, with NIST 610 employed as the bracketing calibrating reference material. The medium-resolution REE analyses are shown to be significantly more accurate and precise (at the 95% confidence level) than low-resolution analyses, particularly in samples characterized by low (ICP-MS methods, particularly those relying on mass analyzers that do not offer tuneable mass-resolution and/or collision cell technologies that can reduce oxide and/or argide formation. Graphical Abstract ᅟ.

  20. Precision and accuracy of ST-EDXRF performance for As determination comparing with ICP-MS and evaluation of As deviation in the soil media.

    Science.gov (United States)

    Akbulut, Songul; Cevik, Ugur; Van, Aydın Ali; De Wael, Karolien; Van Grieken, Rene

    2014-02-01

    The present study was conducted to (i) determine the precision and accuracy of arsenic measurement in soil samples using ST-EDXRF by comparison with the results of ICP-MS analyses and (ii) identify the relationship of As concentration with soil characteristics. For the analysis of samples, inductively coupled plasma mass spectrometry (ICP-MS) and energy dispersive X-ray fluorescence spectrometry (EDXRF) were performed. According to the results found in the soil samples, the addition of HCl to HNO3, used for the digestion gave significant variations in the recovery of As. However, spectral interferences between peaks for As and Pb can affect detection limits and accuracy for XRF analysis. When comparing the XRF and ICP-MS results a correlation was observed with R(2)=0.8414. This means that using a ST-EDXRF spectrometer, it is possible to achieve accurate and precise analysis by the calibration of certified reference materials and choosing an appropriate secondary target. On the other hand, with regard to soil characteristics analyses, the study highlighted that As is mostly anthropogenically enriched in the studied area. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Improved patient repositioning accuracy by integrating an additional jaw fixation into a high precision face mask system in stereotactic radiotherapy of the head

    International Nuclear Information System (INIS)

    Lopatta, E.; Liesenfeld, S.M.; Bank, P.; Guenther, R.; Wiezorek, T.; Wendt, T.G.; Wurm, R.

    2003-01-01

    Background: For high precision radiotherapy of the neurocranium a precise, reproducible positioning technique is the basic pre-requisite. The aim of this study was to assess the influence of a modification of the commercially available stereotactical BrainLab trademark -head mask system on accuracy in patient positioning during fractionated radiotherapy. Material and Methods: 29 patients were treated with stereotactic radiotherapy of the head. Immobilization was provided by a two layer thermoplastic mask system (BrainLab trademark). 18 of these patients received an additional custom made fixation either of the upper jaw (OKF) or of the mandibula (UKF). The positioning accuracy was assessed by measurements of the shifting of anatomical landmarks in relation to therigid mask system on biplanar simulator films using a digital imaging system. Before each measurement a fine adjustment of the simulator to an optical ring system was performed. The reference radiographs were done just before CT-planning. During a 2-7 weeks lasting course of radiotherapy displacement measurements in relation to the reference images for all three dimensions (z, y and x) were done once a week. In 29 patients 844 measurements were analyzed. Results: An additional jaw fixation improves the reproducibility of patient positioning significantly in all three spatial dimensions. The standard deviation in lateral direction (x) was 0.6 mm with jaw fixation vs. 0.7 mm without jaw fixation (p [de

  2. Precision and accuracy in smFRET based structural studies—A benchmark study of the Fast-Nano-Positioning System

    Science.gov (United States)

    Nagy, Julia; Eilert, Tobias; Michaelis, Jens

    2018-03-01

    Modern hybrid structural analysis methods have opened new possibilities to analyze and resolve flexible protein complexes where conventional crystallographic methods have reached their limits. Here, the Fast-Nano-Positioning System (Fast-NPS), a Bayesian parameter estimation-based analysis method and software, is an interesting method since it allows for the localization of unknown fluorescent dye molecules attached to macromolecular complexes based on single-molecule Förster resonance energy transfer (smFRET) measurements. However, the precision, accuracy, and reliability of structural models derived from results based on such complex calculation schemes are oftentimes difficult to evaluate. Therefore, we present two proof-of-principle benchmark studies where we use smFRET data to localize supposedly unknown positions on a DNA as well as on a protein-nucleic acid complex. Since we use complexes where structural information is available, we can compare Fast-NPS localization to the existing structural data. In particular, we compare different dye models and discuss how both accuracy and precision can be optimized.

  3. Effect of radiation dose level on accuracy and precision of manual size measurements in chest tomosynthesis evaluated using simulated pulmonary nodules

    International Nuclear Information System (INIS)

    Soederman, Christina; Allansdotter Johnsson, Aase; Vikgren, Jenny; Rossi Norrlund, Rauni; Molnar, David; Svalkvist, Angelica; Maansson, Lars Gunnar; Baath, Magnus

    2016-01-01

    The aim of the present study was to investigate the dependency of the accuracy and precision of nodule diameter measurements on the radiation dose level in chest tomosynthesis. Artificial ellipsoid-shaped nodules with known dimensions were inserted in clinical chest tomosynthesis images. Noise was added to the images in order to simulate radiation dose levels corresponding to effective doses for a standard-sized patient of 0.06 and 0.04 mSv. These levels were compared with the original dose level, corresponding to an effective dose of 0.12 mSv for a standard-sized patient. Four thoracic radiologists measured the longest diameter of the nodules. The study was restricted to nodules located in high-dose areas of the tomosynthesis projection radiographs. A significant decrease of the measurement accuracy and intra-observer variability was seen for the lowest dose level for a subset of the observers. No significant effect of dose level on the interobserver variability was found. The number of non-measurable small nodules (≤5 mm) was higher for the two lowest dose levels compared with the original dose level. In conclusion, for pulmonary nodules at positions in the lung corresponding to locations in high-dose areas of the projection radiographs, using a radiation dose level resulting in an effective dose of 0.06 mSv to a standard-sized patient may be possible in chest tomosynthesis without affecting the accuracy and precision of nodule diameter measurements to any large extent. However, an increasing number of non-measurable small nodules (≤5 mm) with decreasing radiation dose may raise some concerns regarding an applied general dose reduction for chest tomosynthesis examinations in the clinical praxis. (authors)

  4. Precision, accuracy, cross reactivity and comparability of serum indices measurement on Abbott Architect c8000, Beckman Coulter AU5800 and Roche Cobas 6000 c501 clinical chemistry analyzers.

    Science.gov (United States)

    Nikolac Gabaj, Nora; Miler, Marijana; Vrtarić, Alen; Hemar, Marina; Filipi, Petra; Kocijančić, Marija; Šupak Smolčić, Vesna; Ćelap, Ivana; Šimundić, Ana-Maria

    2018-04-25

    The aim of our study was to perform verification of serum indices on three clinical chemistry platforms. This study was done on three analyzers: Abbott Architect c8000, Beckman Coulter AU5800 (BC) and Roche Cobas 6000 c501. The following analytical specifications were verified: precision (two patient samples), accuracy (sample with the highest concentration of interferent was serially diluted and measured values compared to theoretical values), comparability (120 patients samples) and cross reactivity (samples with increasing concentrations of interferent were divided in two aliquots and remaining interferents were added in each aliquot. Measurements were done before and after adding interferents). Best results for precision were obtained for the H index (0.72%-2.08%). Accuracy for the H index was acceptable for Cobas and BC, while on Architect, deviations in the high concentration range were observed (y=0.02 [0.01-0.07]+1.07 [1.06-1.08]x). All three analyzers showed acceptable results in evaluating accuracy of L index and unacceptable results for I index. The H index was comparable between BC and both, Architect (Cohen's κ [95% CI]=0.795 [0.692-0.898]) and Roche (Cohen's κ [95% CI]=0.825 [0.729-0.922]), while Roche and Architect were not comparable. The I index was not comparable between all analyzer combinations, while the L index was only comparable between Abbott and BC. Cross reactivity analysis mostly showed that serum indices measurement is affected when a combination of interferences is present. There is heterogeneity between analyzers in the hemolysis, icteria, lipemia (HIL) quality performance. Verification of serum indices in routine work is necessary to establish analytical specifications.

  5. Optimizing the accuracy of a helical diode array dosimeter: A comprehensive calibration methodology coupled with a novel virtual inclinometer

    Energy Technology Data Exchange (ETDEWEB)

    Kozelka, Jakub; Robinson, Joshua; Nelms, Benjamin; Zhang, Geoffrey; Savitskij, Dennis; Feygelman, Vladimir [Sun Nuclear Corp., Melbourne, Florida 32940 (United States); Department of Physics, University of South Florida, Tampa, Florida 33612 (United States); Canis Lupus LLC, Sauk County, Wisconsin 53561 (United States); Division of Radiation Oncology, Moffitt Cancer Center, Tampa, Florida 33612 (United States); Sun Nuclear Corp., Melbourne, Florida 32940 (United States); Division of Radiation Oncology, Moffitt Cancer Center, Tampa, Florida 33612 (United States)

    2011-09-15

    Purpose: The goal of any dosimeter is to be as accurate as possible when measuring absolute dose to compare with calculated dose. This limits the uncertainties associated with the dosimeter itself and allows the task of dose QA to focus on detecting errors in the treatment planning (TPS) and/or delivery systems. This work introduces enhancements to the measurement accuracy of a 3D dosimeter comprised of a helical plane of diodes in a volumetric phantom. Methods: We describe the methods and derivations of new corrections that account for repetition rate dependence, intrinsic relative sensitivity per diode, field size dependence based on the dynamic field size determination, and positional correction. Required and described is an accurate ''virtual inclinometer'' algorithm. The system allows for calibrating the array directly against an ion chamber signal collected with high angular resolution. These enhancements are quantitatively validated using several strategies including ion chamber measurements taken using a ''blank'' plastic shell mimicking the actual phantom, and comparison to high resolution dose calculations for a variety of fields: static, simple arcs, and VMAT. A number of sophisticated treatment planning algorithms were benchmarked against ion chamber measurements for their ability to handle a large air cavity in the phantom. Results: Each calibration correction is quantified and presented vs its independent variable(s). The virtual inclinometer is validated by direct comparison to the gantry angle vs time data from machine log files. The effects of the calibration are quantified and improvements are seen in the dose agreement with the ion chamber reference measurements and with the TPS calculations. These improved agreements are a result of removing prior limitations and assumptions in the calibration methodology. Average gamma analysis passing rates for VMAT plans based on the AAPM TG-119 report are 98.4 and 93

  6. Precision and accuracy control of dose calibrator: CAPINTEC CRC 12 in laboratory for radiopharmacy of Nuclear Medicine Institute of Sucre, Bolivia

    International Nuclear Information System (INIS)

    Huanca Sardinas, E; Castro Sacci, O; Torrez Cabero, M; Vasquez Ibanez, M.R; Zambrana Zelada, AJ.

    2013-01-01

    The dose calibrator is one of the indispensable tools in radiopharmacy laboratories of a nuclear medicine department also is mandated to provide accurate readings. A very high doses produce unnecessary radiation exposure to the patient or a very low dose, prolong the acquisition time of the studies affecting the quality of the image. In the present work we did a retrospective analysis of the results of quality checks performed at precision accuracy of the Gauge CRC12 CAPINTEC dose calibrator over a period of 16 years, using sealed certified sources with low power, medium and high: Ba 133 , Cs 137 , Co 60 and Co 57 . The results showed that the lowest standard deviation value was 0.17 for Ba133, relative to Co 57 of 2.97 in the control of accuracy. Accuracy over control values were also lower standard deviation for Ba 133 1.00, relative to Co 57 10.06. Being stated that the CRC12 CAPINTEC activimeter reliability is acceptable during the reporting period and under the conditions indicated. Therefore, we continue to make these quality control procedures and the professional must feel confident that the measurements obtained with it are reliable

  7. Post-operative 3D CT feedback improves accuracy and precision in the learning curve of anatomic ACL femoral tunnel placement.

    Science.gov (United States)

    Sirleo, Luigi; Innocenti, Massimo; Innocenti, Matteo; Civinini, Roberto; Carulli, Christian; Matassi, Fabrizio

    2018-02-01

    To evaluate the feedback from post-operative three-dimensional computed tomography (3D-CT) on femoral tunnel placement in the learning process, to obtain an anatomic anterior cruciate ligament (ACL) reconstruction. A series of 60 consecutive patients undergoing primary ACL reconstruction using autologous hamstrings single-bundle outside-in technique were prospectively included in the study. ACL reconstructions were performed by the same trainee-surgeon during his learning phase of anatomic ACL femoral tunnel placement. A CT scan with dedicated tunnel study was performed in all patients within 48 h after surgery. The data obtained from the CT scan were processed into a three-dimensional surface model, and a true medial view of the lateral femoral condyle was used for the femoral tunnel placement analysis. Two independent examiners analysed the tunnel placements. The centre of femoral tunnel was measured using a quadrant method as described by Bernard and Hertel. The coordinates measured were compared with anatomic coordinates values described in the literature [deep-to-shallow distance (X-axis) 28.5%; high-to-low distance (Y-axis) 35.2%]. Tunnel placement was evaluated in terms of accuracy and precision. After each ACL reconstruction, results were shown to the surgeon to receive an instant feedback in order to achieve accurate correction and improve tunnel placement for the next surgery. Complications and arthroscopic time were also recorded. Results were divided into three consecutive series (1, 2, 3) of 20 patients each. A trend to placing femoral tunnel slightly shallow in deep-to-shallow distance and slightly high in high-to-low distance was observed in the first and the second series. A progressive improvement in tunnel position was recorded from the first to second series and from the second to the third series. Both accuracy (+52.4%) and precision (+55.7%) increased from the first to the third series (p process to improve accuracy and precision of femoral

  8. A Methodology to Assess the Accuracy with which Remote Data Characterize a Specific Surface, as a Function of Full Width at Half Maximum (FWHM: Application to Three Italian Coastal Waters

    Directory of Open Access Journals (Sweden)

    Rosa Maria Cavalli

    2014-01-01

    Full Text Available This methodology assesses the accuracy with which remote data characterizes a surface, as a function of Full Width at Half Maximum (FWHM. The purpose is to identify the best remote data that improves the characterization of a surface, evaluating the number of bands in the spectral range. The first step creates an accurate dataset of remote simulated data, using in situ hyperspectral reflectances. The second step evaluates the capability of remote simulated data to characterize this surface. The spectral similarity measurements, which are obtained using classifiers, provide this capability. The third step examines the precision of this capability. The assumption is that in situ hyperspectral reflectances are considered the “real” reflectances. They are resized with the same spectral range of the remote data. The spectral similarity measurements which are obtained from “real” resized reflectances, are considered “real” measurements. Therefore, the quantity and magnitude of “errors” (i.e., differences between spectral similarity measurements obtained from “real” resized reflectances and from remote data provide the accuracy as a function of FWHM. This methodology was applied to evaluate the accuracy with which CHRIS-mode1, CHRIS-mode2, Landsat5-TM, MIVIS and PRISMA data characterize three coastal waters. Their mean values of uncertainty are 1.59%, 3.79%, 7.75%, 3.15% and 1.18%, respectively.

  9. Assessment of high precision, high accuracy Inductively Coupled Plasma-Optical Emission Spectroscopy to obtain concentration uncertainties less than 0.2% with variable matrix concentrations

    International Nuclear Information System (INIS)

    Rabb, Savelas A.; Olesik, John W.

    2008-01-01

    The ability to obtain high precision, high accuracy measurements in samples with complex matrices using High Performance Inductively Coupled Plasma-Optical Emission Spectroscopy (HP-ICP-OES) was investigated. The Common Analyte Internal Standard (CAIS) procedure was incorporated into the High Performance Inductively Coupled Plasma-Optical Emission Spectroscopy method to correct for matrix-induced changes in emission intensity ratios. Matrix matching and standard addition approaches to minimize matrix-induced errors when using High Performance Inductively Coupled Plasma-Optical Emission Spectroscopy were also assessed. The High Performance Inductively Coupled Plasma-Optical Emission Spectroscopy method was tested with synthetic solutions in a variety of matrices, alloy standard reference materials and geological reference materials

  10. Study of the stiffness for predicting the accuracy of machine tools; Estudio de la rigidez para la prediccion de la precision de las maquinas-herramientas

    Energy Technology Data Exchange (ETDEWEB)

    Ortega, N.; Campa, F.J.; Fernandez Valdivielso, A.; Alonso, U.; Olvera, D.; Compean, F.I.

    2010-07-01

    Machining processes are frequently faced with the challenge of achieving more and more precision and surface qualities. These requirements are usually attained taking into account some process variables, including the cutting parameters and the use or not of refrigerant, leaving aside the mechanical aspects associated with the influence of machine tool itself. There are many sources of error linked with machine-workpiece interaction, but, in general, we can summarize them into two types of error: quasi-static and dynamic. This paper shows the influence of quasi-static error caused by low machine rigidity on the accuracy applied on two very different processes: turning and grinding. For the study of the static stiffness of these two machines, two different methods are proposed, both of them equally valid. The first one is based on separated parameters and the second one on finite elements. (Author).

  11. Accuracy and precision of glucose monitoring are relevant to treatment decision-making and clinical outcome in hospitalized patients with diabetes.

    Science.gov (United States)

    Voulgari, Christina; Tentolouris, Nicholas

    2011-07-01

    The accuracy and precision of three blood glucose meters (BGMs) were evaluated in 600 hospitalized patients with type 1 (n = 200) or type 2 (n = 400) diabetes. Capillary blood glucose values were analyzed with Accu-Chek(®) Aviva [Roche (Hellas) S.A., Maroussi, Greece], Precision-Xceed(®) [Abbott Laboratories (Hellas) S.A., Alimos, Greece], and Glucocard X-Sensor(®) (Menarini Diagnostics S.A., Argyroupolis, Greece). At the same time plasma glucose was analyzed using the World Health Organization's glucose oxidase method. Median plasma glucose values (141.2 [range, 13-553] mg/dL) were significantly different from that produced by the BGMs (P diabetes patients. In all cases, the BGMs were unreliable in sensing hypoglycemia. Multivariate linear regression analysis demonstrated that low blood pressure and hematocrit significantly affected glucose measurements obtained with all three BGMs (P diabetes patients, all three frequently used BGMs undersensed hypoglycemia and oversensed hyperglycemia to some extent. Patients and caregivers should be aware of these restrictions of the BGMs.

  12. Improved accuracy and precision in δ15 NAIR measurements of explosives, urea, and inorganic nitrates by elemental analyzer/isotope ratio mass spectrometry using thermal decomposition.

    Science.gov (United States)

    Lott, Michael J; Howa, John D; Chesson, Lesley A; Ehleringer, James R

    2015-08-15

    Elemental analyzer systems generate N(2) and CO(2) for elemental composition and isotope ratio measurements. As quantitative conversion of nitrogen in some materials (i.e., nitrate salts and nitro-organic compounds) is difficult, this study tests a recently published method - thermal decomposition without the addition of O(2) - for the analysis of these materials. Elemental analyzer/isotope ratio mass spectrometry (EA/IRMS) was used to compare the traditional combustion method (CM) and the thermal decomposition method (TDM), where additional O(2) is eliminated from the reaction. The comparisons used organic and inorganic materials with oxidized and/or reduced nitrogen and included ureas, nitrate salts, ammonium sulfate, nitro esters, and nitramines. Previous TDM applications were limited to nitrate salts and ammonium sulfate. The measurement precision and accuracy were compared to determine the effectiveness of converting materials containing different fractions of oxidized nitrogen into N(2). The δ(13) C(VPDB) values were not meaningfully different when measured via CM or TDM, allowing for the analysis of multiple elements in one sample. For materials containing oxidized nitrogen, (15) N measurements made using thermal decomposition were more precise than those made using combustion. The precision was similar between the methods for materials containing reduced nitrogen. The %N values were closer to theoretical when measured by TDM than by CM. The δ(15) N(AIR) values of purchased nitrate salts and ureas were nearer to the known values when analyzed using thermal decomposition than using combustion. The thermal decomposition method addresses insufficient recovery of nitrogen during elemental analysis in a variety of organic and inorganic materials. Its implementation requires relatively few changes to the elemental analyzer. Using TDM, it is possible to directly calibrate certain organic materials to international nitrate isotope reference materials without off

  13. A point of application study to determine the accuracy, precision and reliability of a low-cost balance plate for center of pressure measurement.

    Science.gov (United States)

    Goble, Daniel J; Khan, Ehran; Baweja, Harsimran S; O'Connor, Shawn M

    2018-04-11

    Changes in postural sway measured via force plate center of pressure have been associated with many aspects of human motor ability. A previous study validated the accuracy and precision of a relatively new, low-cost and portable force plate called the Balance Tracking System (BTrackS). This work compared a laboratory-grade force plate versus BTrackS during human-like dynamic sway conditions generated by an inverted pendulum device. The present study sought to extend previous validation attempts for BTrackS using a more traditional point of application (POA) approach. Computer numerical control (CNC) guided application of ∼155 N of force was applied five times to each of 21 points on five different BTrackS Balance Plate (BBP) devices with a hex-nose plunger. Results showed excellent agreement (ICC > 0.999) between the POAs and measured COP by the BBP devices, as well as high accuracy ( 0.999) providing evidence of almost perfect inter-device reliability. Taken together, these results provide an important, static corollary to the previously obtained dynamic COP results from inverted pendulum testing of the BBP. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Verification of the precision and accuracy of the TPS dosimetric calculations using the 3.0 version MIRS TECDOC-1583 of the IAEA (2008)

    International Nuclear Information System (INIS)

    Gonzalez Perez, Yelina; Rodriguez Zayas, Michael; Perez Guevara, Adrian; Sola Rodriguez, Yeline; Reyes Gonzalez, Tommy; Sanchez Zamora; Luis; Caballero, Roberto

    2009-01-01

    Radiotherapy is one of the basic therapeutic tools to treat malignant tumors. The treatment of a tumor with ionizing radiation is a continuous process with distinct stages, which is the computerized planning, being a fundamental component within this process, it is in this phase are designed and calculated the patient treatment. Systems for Radiotherapy Treatment Planning (TPS) are the tools to perform the treatment planning. The Radiotherapy Service of the Hospital Hermanos Ameijeiras acquired MIRS software version 3.0, which has potential as conventional radiation therapy planning tools and compliance with 3D, multiple imaging studies and calculation of dose according to patient data and equipment. For the complexity of these calculations and the reliability which must have the same, the software should be subjected to rigorous acceptance testing. We verify the precision and accuracy of the TPS dosimetric calculation by applying the most recent protocol of acceptance of the IAEA for these systems (2008). After implementation of the testing set is unable to verify the dose calculations are within the tolerances allowed. (Author)

  15. Addressing the bias problem in the assessment of the quality of life of patients with dementia: determinants of the accuracy and precision of the proxy ratings.

    Science.gov (United States)

    Gomez-Gallego, M; Gomez-Garcia, J; Ato-Lozano, E

    2015-03-01

    We aimed to examine the discrepancy between patients and caregivers' ratings of quality of life in terms of accuracy and precision, and identify factors associated with it, in order to facilitate the use of this scale as dementia progresses. Cross-sectional analytic study. Day care centres. Community-living patients with Alzheimer's disease in early or moderate stage and their principal caregivers. PARTICIPANTS rated patients' quality of life using DEMQOL. The discrepancy was assessed using the individual difference score and the residuals for each domain of DEMQOL. The scores on Mini-Mental State Examination, Geriatric Depression Scale, Neuropsychiatric Inventory, Clinical Insight Rating Scale, Cumulative Illness Rating Scale, Health Utilities Index Mark 3 and Zarit Burden Interview were considered as possible predictors of the discrepancy. A total of 276 subjects participated in the study (138 patients with Alzheimer's disease and their caregivers). Discrepancy measured by individual difference score was lower than that measured by the residuals. Burden and mood-related symptoms explained the positive differences and residuals, while pain, self-perceived depression and cognition determined the negative ones. Differences exist between patients and caregivers' perceptions about subjective states. The evaluations of each informant seem to be influenced by their own emotional state and the inner experience of the effects of the disease. Caregivers' ratings on DEMQOL could be useful to monitor the efficacy of any treatment whenever burden is low and patients have no great physical or emotional suffering.

  16. Real-Time 3D Image Guidance Using a Standard LINAC: Measured Motion, Accuracy, and Precision of the First Prospective Clinical Trial of Kilovoltage Intrafraction Monitoring-Guided Gating for Prostate Cancer Radiation Therapy

    DEFF Research Database (Denmark)

    Keall, Paul J; Ng, Jin Aun; Juneja, Prabhjot

    2016-01-01

    for prostate cancer radiation therapy. In this paper we report on the measured motion accuracy and precision using real-time KIM-guided gating. METHODS AND MATERIALS: Imaging and motion information from the first 200 fractions from 6 patient prostate cancer radiation therapy volumetric modulated arc therapy...... treatments were analyzed. A 3-mm/5-second action threshold was used to trigger a gating event where the beam is paused and the couch position adjusted to realign the prostate to the treatment isocenter. To quantify the in vivo accuracy and precision, KIM was compared with simultaneously acquired k...

  17. Accuracy and precision of the CKD-EPI and MDRD predictive equations compared with glomerular filtration rate measured by inulin clearance in a Saudi population.

    Science.gov (United States)

    Al-Wakeel, Jamal Saleh

    2016-01-01

    Predictive equations for estimating glomerular filtration rate (GFR) in different clinical conditions should be validated by comparing with the measurement of GFR using inulin clearance, a highly accurate measure of GFR. Our aim was to validate the Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) and Modification of Diet in Renal Disease (MDRD) equations by comparing it to the GFR measured using inulin clearance in chronic kidney disease (CKD) patients. Cross-sectional study performed in adult Saudi patients with CKD. King Saud University Affiliated Hospital, Riyadh, Saudi Arabia in 2014. We compared GFR measured by inulin clearance with the estimated GFR calculated using CKD-EPI and MDRD predictive formulas. Correlation, bias, precision and accuracy between the estimated GFR and inulin clearance. Comparisons were made in 31 participants (23 CKD and 8 transplanted), including 19 males (mean age 42.2 [15] years and weight 68.7 [18] kg). GFR using inulin was 51.54 (33.8) mL/min/1.73 m2 in comparison to inulin clearance, the GFR by the predictive equations was: CKD-EPI creatinine 52.6 (34.4) mL/ min/1.73 m2 (P=.490), CKD-EPI cystatin C 41.39 (30.30) mL/min/1.73 m2 (P=.002), CKD creatinine-cystatin C 45.03 (30.9) mL/min/1.73 m2 (P=.004) and MDRD GFR 48.35 (31.5) mL/min/1.73 m2 (P=.028) (statistical comparisons vs inulin). Bland-Altman plots demonstrated that GFR estimated by the CKD-EPI creatinine was the most accurate compared with inulin clearance, having a mean difference (estimated bias) and limits of agreement of -1.1 (15.6,-17.7). By comparison the mean differences for predictive equations were: CKD-EPI cystatin C 10.2 (43.7,-23.4), CKD creatinine-cystatin C 6.5 (29.3,-16.3) and MDRD 3.2 (18.3,-11.9). except for CKD-EPI creatinine, all of the equations underestimated GFR in comparison with inulin clearance. When compared with inulin clearance, the CKD-EPI creatinine equation is the most accurate, precise and least biased equation for estimation of GFR

  18. Development and validation of an automated and marker-free CT-based spatial analysis method (CTSA) for assessment of femoral hip implant migration: In vitro accuracy and precision comparable to that of radiostereometric analysis (RSA).

    Science.gov (United States)

    Scheerlinck, Thierry; Polfliet, Mathias; Deklerck, Rudi; Van Gompel, Gert; Buls, Nico; Vandemeulebroucke, Jef

    2016-01-01

    We developed a marker-free automated CT-based spatial analysis (CTSA) method to detect stem-bone migration in consecutive CT datasets and assessed the accuracy and precision in vitro. Our aim was to demonstrate that in vitro accuracy and precision of CTSA is comparable to that of radiostereometric analysis (RSA). Stem and bone were segmented in 2 CT datasets and both were registered pairwise. The resulting rigid transformations were compared and transferred to an anatomically sound coordinate system, taking the stem as reference. This resulted in 3 translation parameters and 3 rotation parameters describing the relative amount of stem-bone displacement, and it allowed calculation of the point of maximal stem migration. Accuracy was evaluated in 39 comparisons by imposing known stem migration on a stem-bone model. Precision was estimated in 20 comparisons based on a zero-migration model, and in 5 patients without stem loosening. Limits of the 95% tolerance intervals (TIs) for accuracy did not exceed 0.28 mm for translations and 0.20° for rotations (largest standard deviation of the signed error (SD(SE)): 0.081 mm and 0.057°). In vitro, limits of the 95% TI for precision in a clinically relevant setting (8 comparisons) were below 0.09 mm and 0.14° (largest SD(SE): 0.012 mm and 0.020°). In patients, the precision was lower, but acceptable, and dependent on CT scan resolution. CTSA allows detection of stem-bone migration with an accuracy and precision comparable to that of RSA. It could be valuable for evaluation of subtle stem loosening in clinical practice.

  19. Analysis of the accuracy of certain methods used for measuring very low reactivities; Analyse de la precision de certaines methodes de mesure de tres basses reactivites

    Energy Technology Data Exchange (ETDEWEB)

    Valat, J; Stern, T E

    1964-07-01

    The rapid measurement of anti-reactivities, in particular very low ones (i.e. a few tens of {beta}) appears to be an interesting method for the automatic start-up a reactor and its optimisation. With this in view, the present report explores the various methods studied essentially from the point of view of the time required for making the measurement with a given statistical accuracy, especially as far as very low activities are concerned. The statistical analysis is applied in turn to: the methods for the natural background noise (auto-correlation and spectral density); the sinusoidal excitation methods for the reactivity or the source, with synchronous detection ; the periodic source excitation method using pulsed neutrons. Finally, the statistical analysis leads to the suggestion of a new method of source excitation using neutronic random square waves combined with an intercorrelation between the random excitation and the resulting output. (authors) [French] La mesure rapide des antireactivites, en particulier celle des tres basses (soit quelques dizaines de {beta}), apparait comme une voie interessante pour le demarrage automatique d'un reacteur et son optimalisation. Dans cette optique, le present rapport explore diverses methodes etudiees essentiellement sous l'angle de la duree de mesure necessaire a une precision relative statistique donnee, plus particulierement en ce qui concerne les tres basses reactivites. L'analyse statistique porte successivement sur: les methodes du bruit de fond naturel (autocorrelation et densite spectrale); les methodes d'excitation sinusoidale de reactivite ou de source, avec detection synchrone; la methode d'excitation periodique de source par neutrons pulses. Enfin l'analyse statistique amene a proposer une methode nouvelle d'excitation de source par creneaux neutroniques aleatoires alliee a une intercorrelation entre l'excitation aleatoire et la sortie resultante. (auteurs)

  20. Analysis of the accuracy and precision of the McMaster method in detection of the eggs of Toxocara and Trichuris species (Nematoda) in dog faeces.

    Science.gov (United States)

    Kochanowski, Maciej; Dabrowska, Joanna; Karamon, Jacek; Cencek, Tomasz; Osiński, Zbigniew

    2013-07-01

    The aim of this study was to determine the accuracy and precision of McMaster method with Raynaud's modification in the detection of the eggs of the nematodes Toxocara canis (Werner, 1782) and Trichuris ovis (Abildgaard, 1795) in faeces of dogs. Four variants of McMaster method were used for counting: in one grid, two grids, the whole McMaster chamber and flotation in the tube. One hundred sixty samples were prepared from dog faeces (20 repetitions for each egg quantity) containing 15, 25, 50, 100, 150, 200, 250 and 300 eggs of T. canis and T. ovis in 1 g of faeces. To compare the influence of kind of faeces on the results, samples of dog faeces were enriched at the same levels with the eggs of another nematode, Ascaris suum Goeze, 1782. In addition, 160 samples of pig faeces were prepared and enriched only with A. suum eggs in the same way. The highest limit of detection (the lowest level of eggs that were detected in at least 50% of repetitions) in all McMaster chamber variants were obtained for T. canis eggs (25-250 eggs/g faeces). In the variant with flotation in the tube, the highest limit of detection was obtained for T. ovis eggs (100 eggs/g). The best results of the limit of detection, sensitivity and the lowest coefficients of variation were obtained with the use of the whole McMaster chamber variant. There was no significant impact of properties of faeces on the obtained results. Multiplication factors for the whole chamber were calculated on the basis of the transformed equation of the regression line, illustrating the relationship between the number of detected eggs and that of the eggs added to the'sample. Multiplication factors calculated for T. canis and T. ovis eggs were higher than those expected using McMaster method with Raynaud modification.

  1. Does methodology matter in eyewitness identification research? The effect of live versus video exposure on eyewitness identification accuracy.

    Science.gov (United States)

    Pozzulo, Joanna D; Crescini, Charmagne; Panton, Tasha

    2008-01-01

    The present study examined the effect of mode of target exposure (live versus video) on eyewitness identification accuracy. Adult participants (N=104) were exposed to a staged crime that they witnessed either live or on videotape. Participants were then asked to rate their stress and arousal levels prior to being presented with either a target-present or -absent simultaneous lineup. Across target-present and -absent lineups, mode of target exposure did not have a significant effect on identification accuracy. However, mode of target exposure was found to have a significant effect on stress and arousal levels. Participants who witnessed the crime live had higher levels of stress and arousal than those who were exposed to the videotaped crime. A higher level of arousal was significantly related to poorer identification accuracy for those in the video condition. For participants in the live condition however, stress and arousal had no effect on eyewitness identification accuracy. Implications of these findings in regards to the generalizability of laboratory-based research on eyewitness testimony to real-life crime are discussed.

  2. The use of statistical methodology to determine the accuracy of grading within a diabetic retinopathy screening programme

    OpenAIRE

    Oke, J L; Stratton, I M; Aldington, S J; Stevens, R J; Scanlon, Peter H

    2016-01-01

    AIMS:\\ud We aimed to use longitudinal data from an established screening programme with good quality assurance and quality control procedures and a stable well-trained workforce to determine the accuracy of grading in diabetic retinopathy screening.\\ud METHODS:\\ud We used a continuous time-hidden Markov model with five states to estimate the probability of true progression or regression of retinopathy and the conditional probability of an observed grade given the true grade (misclassification...

  3. Precision of dual-energy X-ray absorptiometry of the knee and heel: methodology and implications for research to reduce bone mineral loss after spinal cord injury.

    Science.gov (United States)

    Peppler, W T; Kim, W J; Ethans, K; Cowley, K C

    2017-05-01

    Methodological validation of dual-energy x-ray absorptiometry (DXA)-based measures of leg bone mineral density (BMD) based on the guidelines of the International Society for Clinical Densitometry. The primary objective of this study was to determine the precision of BMD estimates at the knee and heel using the manufacturer provided DXA acquisition algorithm. The secondary objective was to determine the smallest change in DXA-based measurement of BMD that should be surpassed (least significant change (LSC)) before suggesting that a biological change has occurred in the distal femur, proximal tibia and calcaneus. Academic Research Centre, Canada. Ten people with motor-complete SCI of at least 2 years duration and 10 people from the general population volunteered to have four DXA-based measurements taken of their femur, tibia and calcaneus. BMDs for seven regions of interest (RIs) were calculated, as were short-term precision (root-mean-square (RMS) standard deviation (g cm -2 ), RMS-coefficient of variation (RMS-CV, %)) and LSC. Overall, RMS-CV values were similar between SCI (3.63-10.20%, mean=5.3%) and able-bodied (1.85-5.73%, mean=4%) cohorts, despite lower absolute BMD values at each RIs in those with SCI (35%, heel to 54%, knee; P10% are needed to detect differences between treated and untreated groups in studies aimed at reducing bone mineral loss after SCI.

  4. Best Practices for Mudweight Window Generation and Accuracy Assessment between Seismic Based Pore Pressure Prediction Methodologies for a Near-Salt Field in Mississippi Canyon, Gulf of Mexico

    Science.gov (United States)

    Mannon, Timothy Patrick, Jr.

    Improving well design has and always will be the primary goal in drilling operations in the oil and gas industry. Oil and gas plays are continuing to move into increasingly hostile drilling environments, including near and/or sub-salt proximities. The ability to reduce the risk and uncertainly involved in drilling operations in unconventional geologic settings starts with improving the techniques for mudweight window modeling. To address this issue, an analysis of wellbore stability and well design improvement has been conducted. This study will show a systematic approach to well design by focusing on best practices for mudweight window projection for a field in Mississippi Canyon, Gulf of Mexico. The field includes depleted reservoirs and is in close proximity of salt intrusions. Analysis of offset wells has been conducted in the interest of developing an accurate picture of the subsurface environment by making connections between depth, non-productive time (NPT) events, and mudweights used. Commonly practiced petrophysical methods of pore pressure, fracture pressure, and shear failure gradient prediction have been applied to key offset wells in order to enhance the well design for two proposed wells. For the first time in the literature, the accuracy of the commonly accepted, seismic interval velocity based and the relatively new, seismic frequency based methodologies for pore pressure prediction are qualitatively and quantitatively compared for accuracy. Accuracy standards will be based on the agreement of the seismic outputs to pressure data obtained while drilling and petrophysically based pore pressure outputs for each well. The results will show significantly higher accuracy for the seismic frequency based approach in wells that were in near/sub-salt environments and higher overall accuracy for all of the wells in the study as a whole.

  5. Performance assessment of a cavity ring-down laser spectrometer: achieving better precision and accuracy in the measurement of δ18O and δ2H in liquid water samples

    International Nuclear Information System (INIS)

    Prado-Pérez, A J; Rodríguez-Arévalo, J; Díaz-Teijeiro, M F

    2014-01-01

    The development of new isotopic laser-based analyzers currently represents a clear alternative to conventional isotope ratio mass spectrometers. However, this analytical technique also suffers some disadvantages such as the memory effect, problems related to the overall stability of the equipment and other issues associated with the injection system, essentially regarding the syringe's longevity. This paper aims to minimize these disadvantages in order to increase the overall performance, in terms of precision and accuracy, of these kinds of analyzers. The main results of the experiments carried out in this paper have shown that: (i) the minimum number of discarded injections needed to eliminate the memory effect can be determined just considering the expected isotopic signature difference between two consecutive samples; (ii) both accuracy and precision of the isotopic measurements increase with increasing injection volume up to 2.1–2.2 µL; (iii) it is possible to extend the syringe lifetime by almost a factor of 6 by using n-methyl 2-pyrrolidone as a lubricant. Besides, it has been concluded that, by using the appropriate procedure, the main disadvantages associated with CRDS laser spectroscopy analyzers can be minimized, achieving measurement accuracy and precision of the order of ±0.05 ‰ for δ 18 O and ±0.3 ‰ for δ 2 H. (paper)

  6. SU-E-J-03: Characterization of the Precision and Accuracy of a New, Preclinical, MRI-Guided Focused Ultrasound System for Image-Guided Interventions in Small-Bore, High-Field Magnets

    International Nuclear Information System (INIS)

    Ellens, N; Farahani, K

    2015-01-01

    Purpose: MRI-guided focused ultrasound (MRgFUS) has many potential and realized applications including controlled heating and localized drug delivery. The development of many of these applications requires extensive preclinical work, much of it in small animal models. The goal of this study is to characterize the spatial targeting accuracy and reproducibility of a preclinical high field MRgFUS system for thermal ablation and drug delivery applications. Methods: The RK300 (FUS Instruments, Toronto, Canada) is a motorized, 2-axis FUS positioning system suitable for small bore (72 mm), high-field MRI systems. The accuracy of the system was assessed in three ways. First, the precision of the system was assessed by sonicating regular grids of 5 mm squares on polystyrene plates and comparing the resulting focal dimples to the intended pattern, thereby assessing the reproducibility and precision of the motion control alone. Second, the targeting accuracy was assessed by imaging a polystyrene plate with randomly drilled holes and replicating the hole pattern by sonicating the observed hole locations on intact polystyrene plates and comparing the results. Third, the practicallyrealizable accuracy and precision were assessed by comparing the locations of transcranial, FUS-induced blood-brain-barrier disruption (BBBD) (observed through Gadolinium enhancement) to the intended targets in a retrospective analysis of animals sonicated for other experiments. Results: The evenly-spaced grids indicated that the precision was 0.11 +/− 0.05 mm. When image-guidance was included by targeting random locations, the accuracy was 0.5 +/− 0.2 mm. The effective accuracy in the four rodent brains assessed was 0.8 +/− 0.6 mm. In all cases, the error appeared normally distributed (p<0.05) in both orthogonal axes, though the left/right error was systematically greater than the superior/inferior error. Conclusions: The targeting accuracy of this device is sub-millimeter, suitable for many

  7. SU-E-J-03: Characterization of the Precision and Accuracy of a New, Preclinical, MRI-Guided Focused Ultrasound System for Image-Guided Interventions in Small-Bore, High-Field Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Ellens, N [Johns Hopkins University, Baltimore, Maryland (United States); Farahani, K [National Cancer Institute, Bethesda, MD (United States)

    2015-06-15

    Purpose: MRI-guided focused ultrasound (MRgFUS) has many potential and realized applications including controlled heating and localized drug delivery. The development of many of these applications requires extensive preclinical work, much of it in small animal models. The goal of this study is to characterize the spatial targeting accuracy and reproducibility of a preclinical high field MRgFUS system for thermal ablation and drug delivery applications. Methods: The RK300 (FUS Instruments, Toronto, Canada) is a motorized, 2-axis FUS positioning system suitable for small bore (72 mm), high-field MRI systems. The accuracy of the system was assessed in three ways. First, the precision of the system was assessed by sonicating regular grids of 5 mm squares on polystyrene plates and comparing the resulting focal dimples to the intended pattern, thereby assessing the reproducibility and precision of the motion control alone. Second, the targeting accuracy was assessed by imaging a polystyrene plate with randomly drilled holes and replicating the hole pattern by sonicating the observed hole locations on intact polystyrene plates and comparing the results. Third, the practicallyrealizable accuracy and precision were assessed by comparing the locations of transcranial, FUS-induced blood-brain-barrier disruption (BBBD) (observed through Gadolinium enhancement) to the intended targets in a retrospective analysis of animals sonicated for other experiments. Results: The evenly-spaced grids indicated that the precision was 0.11 +/− 0.05 mm. When image-guidance was included by targeting random locations, the accuracy was 0.5 +/− 0.2 mm. The effective accuracy in the four rodent brains assessed was 0.8 +/− 0.6 mm. In all cases, the error appeared normally distributed (p<0.05) in both orthogonal axes, though the left/right error was systematically greater than the superior/inferior error. Conclusions: The targeting accuracy of this device is sub-millimeter, suitable for many

  8. The use of statistical methodology to determine the accuracy of grading within a diabetic retinopathy screening programme.

    Science.gov (United States)

    Oke, J L; Stratton, I M; Aldington, S J; Stevens, R J; Scanlon, P H

    2016-07-01

    We aimed to use longitudinal data from an established screening programme with good quality assurance and quality control procedures and a stable well-trained workforce to determine the accuracy of grading in diabetic retinopathy screening. We used a continuous time-hidden Markov model with five states to estimate the probability of true progression or regression of retinopathy and the conditional probability of an observed grade given the true grade (misclassification). The true stage of retinopathy was modelled as a function of the duration of diabetes and HbA1c . The modelling dataset consisted of 65 839 grades from 14 187 people. The median number [interquartile range (IQR)] of examinations was 5 (3, 6) and the median (IQR) interval between examinations was 1.04 (0.99, 1.17) years. In total, 14 227 grades (21.6%) were estimated as being misclassified, 10 592 (16.1%) represented over-grading and 3635 (5.5%) represented under-grading. There were 1935 (2.9%) misclassified referrals, 1305 were false-positive results (2.2%) and 630 were false-negative results (11.0%). Misclassification of background diabetic retinopathy as no detectable retinopathy was common (3.4% of all grades) but rarely preceded referable maculopathy or retinopathy. Misclassification between lower grades of retinopathy is not uncommon but is unlikely to lead to significant delays in referring people for sight-threatening retinopathy. © 2015 The Authors. Diabetic Medicine published by John Wiley & Sons Ltd on behalf of Diabetes UK.

  9. Fine-resolution repeat topographic surveying of dryland landscapes using UAS-based structure-from-motion photogrammetry: Assessing accuracy and precision against traditional ground-based erosion measurements

    Science.gov (United States)

    Gillian, Jeffrey K.; Karl, Jason W.; Elaksher, Ahmed; Duniway, Michael C.

    2017-01-01

    Structure-from-motion (SfM) photogrammetry from unmanned aerial system (UAS) imagery is an emerging tool for repeat topographic surveying of dryland erosion. These methods are particularly appealing due to the ability to cover large landscapes compared to field methods and at reduced costs and finer spatial resolution compared to airborne laser scanning. Accuracy and precision of high-resolution digital terrain models (DTMs) derived from UAS imagery have been explored in many studies, typically by comparing image coordinates to surveyed check points or LiDAR datasets. In addition to traditional check points, this study compared 5 cm resolution DTMs derived from fixed-wing UAS imagery with a traditional ground-based method of measuring soil surface change called erosion bridges. We assessed accuracy by comparing the elevation values between DTMs and erosion bridges along thirty topographic transects each 6.1 m long. Comparisons occurred at two points in time (June 2014, February 2015) which enabled us to assess vertical accuracy with 3314 data points and vertical precision (i.e., repeatability) with 1657 data points. We found strong vertical agreement (accuracy) between the methods (RMSE 2.9 and 3.2 cm in June 2014 and February 2015, respectively) and high vertical precision for the DTMs (RMSE 2.8 cm). Our results from comparing SfM-generated DTMs to check points, and strong agreement with erosion bridge measurements suggests repeat UAS imagery and SfM processing could replace erosion bridges for a more synoptic landscape assessment of shifting soil surfaces for some studies. However, while collecting the UAS imagery and generating the SfM DTMs for this study was faster than collecting erosion bridge measurements, technical challenges related to the need for ground control networks and image processing requirements must be addressed before this technique could be applied effectively to large landscapes.

  10. Accuracy of the Precision® point-of-care ketone test examined by liquid chromatography tandem-mass spectrometry (LC-MS/MS) in the same fingerstick sample.

    Science.gov (United States)

    Janssen, Marcel J W; Hendrickx, Ben H E; Habets-van der Poel, Carin D; van den Bergh, Joop P W; Haagen, Anton A M; Bakker, Jaap A

    2010-12-01

    The Precision(®) (Abbott Diabetes Care) point-of-care biosensor test strips are widely used by patients with diabetes and clinical laboratories for measurement of plasma β-hydroxybutyrate (β-HB) concentrations in capillary blood samples obtained by fingerstick. In the literature, this procedure has been validated only against the enzymatic determination of β-HB in venous plasma, i.e., the method to which the Precision(®) has been calibrated. In this study, the Precision(®) Xceed was compared to a methodologically different and superior procedure: determination of β-HB by liquid chromatography tandem-mass spectrometry (LC-MS/MS) in capillary blood spots. Blood spots were obtained from the same fingerstick sample from out of which Precision(®) measurements were performed. Linearity was tested by adding varying amounts of standard to an EDTA venous whole blood matrix. The Precision(®) was in good agreement with LC-MS/MS within the measuring range of 0.0-6.0 mmol/L (Passing and Bablok regression: slope=1.20 and no significant intercept, R=0.97, n=59). Surprisingly, the Precision(®) showed non-linearity and full saturation at concentrations above 6.0 mmol/L, which were confirmed by a standard addition experiment. Results obtained at the saturation level varied between 3.0 and 6.5 mmol/L. The Precision(®) β-HB test strips demonstrate good comparison with LC-MS/MS. Inter-individual variation around the saturation level, however, is large. Therefore, we advise reporting readings above 3.0 as >3.0 mmol/L. The test is valid for use in the clinically relevant range of 0.0-3.0 mmol/L.

  11. Improving accuracy and precision of ice core δD(CH4 analyses using methane pre-pyrolysis and hydrogen post-pyrolysis trapping and subsequent chromatographic separation

    Directory of Open Access Journals (Sweden)

    M. Bock

    2014-07-01

    Full Text Available Firn and polar ice cores offer the only direct palaeoatmospheric archive. Analyses of past greenhouse gas concentrations and their isotopic compositions in air bubbles in the ice can help to constrain changes in global biogeochemical cycles in the past. For the analysis of the hydrogen isotopic composition of methane (δD(CH4 or δ2H(CH4 0.5 to 1.5 kg of ice was hitherto used. Here we present a method to improve precision and reduce the sample amount for δD(CH4 measurements in (ice core air. Pre-concentrated methane is focused in front of a high temperature oven (pre-pyrolysis trapping, and molecular hydrogen formed by pyrolysis is trapped afterwards (post-pyrolysis trapping, both on a carbon-PLOT capillary at −196 °C. Argon, oxygen, nitrogen, carbon monoxide, unpyrolysed methane and krypton are trapped together with H2 and must be separated using a second short, cooled chromatographic column to ensure accurate results. Pre- and post-pyrolysis trapping largely removes the isotopic fractionation induced during chromatographic separation and results in a narrow peak in the mass spectrometer. Air standards can be measured with a precision better than 1‰. For polar ice samples from glacial periods, we estimate a precision of 2.3‰ for 350 g of ice (or roughly 30 mL – at standard temperature and pressure (STP – of air with 350 ppb of methane. This corresponds to recent tropospheric air samples (about 1900 ppb CH4 of about 6 mL (STP or about 500 pmol of pure CH4.

  12. Evaluation of the lower limit of accuracy in a virtual simulation system; Evaluacion del limite inferior de precision en un sistema de simulacion virtual

    Energy Technology Data Exchange (ETDEWEB)

    Bea Gilbert, J.; Banos Capilla, M. C.; Garcia Martinez, M. A.; Ros Garcia, L.; Gil Deltoro, P.; Larrea Rabassa, L. M.; Lopez Munoz, E.

    2011-07-01

    The assessment of tumor margins in Radiotherapy is linked to the quality and accuracy of treatment. The determination of a reliable PTV is determined by multiple components, such as determining the GTV (or CTV), their physiological movements and reproducibility of placement in the diagnosis and treatment units, among others. Likewise, separate the various variables is a complex process dependent largely on the diagnostic units, locking systems and tumor location. Our intention is to obtain a threshold for determining treatment volumes based on these parameters.

  13. Establishing the accuracy of asteroseismic mass and radius estimates of giant stars - I. Three eclipsing systems at [Fe/H] ˜ -0.3 and the need for a large high-precision sample

    Science.gov (United States)

    Brogaard, K.; Hansen, C. J.; Miglio, A.; Slumstrup, D.; Frandsen, S.; Jessen-Hansen, J.; Lund, M. N.; Bossini, D.; Thygesen, A.; Davies, G. R.; Chaplin, W. J.; Arentoft, T.; Bruntt, H.; Grundahl, F.; Handberg, R.

    2018-05-01

    We aim to establish and improve the accuracy level of asteroseismic estimates of mass, radius, and age of giant stars. This can be achieved by measuring independent, accurate, and precise masses, radii, effective temperatures and metallicities of long period eclipsing binary stars with a red giant component that displays solar-like oscillations. We measured precise properties of the three eclipsing binary systems KIC 7037405, KIC 9540226, and KIC 9970396 and estimated their ages be 5.3 ± 0.5, 3.1 ± 0.6, and 4.8 ± 0.5 Gyr. The measurements of the giant stars were compared to corresponding measurements of mass, radius, and age using asteroseismic scaling relations and grid modelling. We found that asteroseismic scaling relations without corrections to Δν systematically overestimate the masses of the three red giants by 11.7 per cent, 13.7 per cent, and 18.9 per cent, respectively. However, by applying theoretical correction factors fΔν according to Rodrigues et al. (2017), we reached general agreement between dynamical and asteroseismic mass estimates, and no indications of systematic differences at the precision level of the asteroseismic measurements. The larger sample investigated by Gaulme et al. (2016) showed a much more complicated situation, where some stars show agreement between the dynamical and corrected asteroseismic measures while others suggest significant overestimates of the asteroseismic measures. We found no simple explanation for this, but indications of several potential problems, some theoretical, others observational. Therefore, an extension of the present precision study to a larger sample of eclipsing systems is crucial for establishing and improving the accuracy of asteroseismology of giant stars.

  14. The newest precision measurement

    International Nuclear Information System (INIS)

    Lee, Jing Gu; Lee, Jong Dae

    1974-05-01

    This book introduces basic of precision measurement, measurement of length, limit gauge, measurement of angles, measurement of surface roughness, measurement of shapes and locations, measurement of outline, measurement of external and internal thread, gear testing, accuracy inspection of machine tools, three dimension coordinate measuring machine, digitalisation of precision measurement, automation of precision measurement, measurement of cutting tools, measurement using laser, and point of choosing length measuring instrument.

  15. Enhancement of precision and accuracy by Monte-Carlo simulation of a well-type pressurized ionization chamber used in radionuclide metrology

    International Nuclear Information System (INIS)

    Kryeziu, D.

    2006-09-01

    The aim of this work was to test and validate the Monte-Carlo (MC) ionization chamber simulation method in calculating the activity of radioactive solutions. This is required when no or not sufficient experimental calibration figures are available as well as to improve the accuracy of activity measurements for other radionuclides. Well-type or 4π γ ISOCAL IV ionization chambers (IC) are widely used in many national standard laboratories around the world. As secondary standard measuring systems these radionuclide calibrators serve to maintain measurement consistency checks and to ensure the quality of standards disseminated to users for a wide range of radionuclide where many of them are with special interest in nuclear medicine as well as in different applications on radionuclide metrology. For the studied radionuclides the calibration figures (efficiencies) and their respective volume correction factors are determined by using the PENELOPE MC computer code system. The ISOCAL IV IC filled with nitrogen gas at approximately 1 MPa is simulated. The simulated models of the chamber are designed by means of reduced quadric equation and applying the appropriate mathematical transformations. The simulations are done for various container geometries of the standard solution which take forms of: i) sealed Jena glass 5 ml PTB standard ampoule, ii) 10 ml (P6) vial and iii) 10 R Schott Type 1+ vial. Simulation of the ISOCAL IV IC is explained. The effect of density variation of the nitrogen filling gas on the sensitivity of the chamber is investigated. The code is also used to examine the effects of using lead and copper shields as well as to evaluate the sensitivity of the chamber to electrons and positrons. Validation of the Monte-Carlo simulation method has been proved by comparing the Monte-Carlo simulation calculated and experimental calibration figures available from the National Physical Laboratory (NPL) England which are deduced from the absolute activity

  16. Orthopaedic measurements with computed radiography: Methodological development, accuracy, and radiation dose with special reference to the weight-bearing lower extremity and the dislocating patella

    International Nuclear Information System (INIS)

    Sanfridsson, J.

    2001-01-01

    The overall aim of this study was to develop and evaluate a measurement system for computed radiography and Picture Archiving and Communication Systems, permitting measurements of long distances and angles in and between related images. The developed measurement system, which was based on the QUESTOR Precision Radiography system, was applied to the weight-bearing knee with special reference to the dislocating patella. The QPR system modified for CR fulfilled the criteria for measuring the weight-bearing knee. The special measuring assistance tools that were developed were important for the implementation of CR and PACS, particularly in workstations programmed for musculoskeletal radiology. The energy imparted to the patient was reduced by 98% at the lowest exposure of the CR-system, compared with our conventional analogue method, without loss of diagnostic accuracy. The CR technique creates a possibility, to an extent not previously feasible, to differentiate the exposure parameters (and thus minimise the radiation dose to the patient) by carefully considering the purpose of the examination. A radiographic method for measuring the rotation of the femur and the tibia, and the patellar translation was developed and applied to healthy volunteers. The introduced patellar variables have yielded new insights into the complex sequence of motions between the femur, tibia, and patella. The patients with a dislocating patella were subdivided into one 'clean' group of spontaneous dislocations and one group with various traumas in the history, which thus resulted in two groups with distinct radiographic differences. The Q-angle was decreased in knees that had suffered dislocations, and the traditional surgical treatment with a further reduction of the Q-angle must be challenged. The use of clinical measurements of the Q-angle was not an optimal way to evaluate the mechanical alignment in the patellofemoral joint under physiological conditions. In this study, we have proved

  17. High School Students' Accuracy in Estimating the Cost of College: A Proposed Methodological Approach and Differences among Racial/Ethnic Groups and College Financial-Related Factors

    Science.gov (United States)

    Nienhusser, H. Kenny; Oshio, Toko

    2017-01-01

    High school students' accuracy in estimating the cost of college (AECC) was examined by utilizing a new methodological approach, the absolute-deviation-continuous construct. This study used the High School Longitudinal Study of 2009 (HSLS:09) data and examined 10,530 11th grade students in order to measure their AECC for 4-year public and private…

  18. Precision manufacturing

    CERN Document Server

    Dornfeld, David

    2008-01-01

    Today there is a high demand for high-precision products. The manufacturing processes are now highly sophisticated and derive from a specialized genre called precision engineering. Precision Manufacturing provides an introduction to precision engineering and manufacturing with an emphasis on the design and performance of precision machines and machine tools, metrology, tooling elements, machine structures, sources of error, precision machining processes and precision process planning. As well as discussing the critical role precision machine design for manufacturing has had in technological developments over the last few hundred years. In addition, the influence of sustainable manufacturing requirements in precision processes is introduced. Drawing upon years of practical experience and using numerous examples and illustrative applications, David Dornfeld and Dae-Eun Lee cover precision manufacturing as it applies to: The importance of measurement and metrology in the context of Precision Manufacturing. Th...

  19. Comparison of the precision and accuracy of digital versus analogue gamma-ray spectrometric systems used in INAA for evaluation of homogeneity and certification of reference materials of the IAEA

    International Nuclear Information System (INIS)

    Makarewicz, M.; Burns, K.

    2000-01-01

    Performance of three commercial gamma-ray spectrometric systems was evaluated for precision and accuracy prior to use in characterization of reference materials. Two of the systems were based on fast processing of the analogue signal from the amplifier (EGG Ortec model 672) using a loss free counting module (Canberra model LFC 599) interfaced to one of two analog-to-digital converters (Canberra models 8713 or 8715). The third system was based on a digital signal processor (Canberra model DSP 9660). Performance of the systems was tested over a range of count rates up to a maximum of 70,000 counts per second (dead time up to 90%) using 60 Co and 137 Cs sources. Best resolution was achieved with an analogue system with ADC 8713. The analytical results obtained with the digital system show the lowest and well-quantified uncertainty. (author)

  20. Orthopaedic measurements with computed radiography: Methodological development, accuracy, and radiation dose with special reference to the weight-bearing lower extremity and the dislocating patella

    Energy Technology Data Exchange (ETDEWEB)

    Sanfridsson, J. [Univ. Hospital, Lund (Sweden). Dept. of Diagnostic Radiology

    2001-03-01

    The overall aim of this study was to develop and evaluate a measurement system for computed radiography and Picture Archiving and Communication Systems, permitting measurements of long distances and angles in and between related images. The developed measurement system, which was based on the QUESTOR Precision Radiography system, was applied to the weight-bearing knee with special reference to the dislocating patella. The QPR system modified for CR fulfilled the criteria for measuring the weight-bearing knee. The special measuring assistance tools that were developed were important for the implementation of CR and PACS, particularly in workstations programmed for musculoskeletal radiology. The energy imparted to the patient was reduced by 98% at the lowest exposure of the CR-system, compared with our conventional analogue method, without loss of diagnostic accuracy. The CR technique creates a possibility, to an extent not previously feasible, to differentiate the exposure parameters (and thus minimise the radiation dose to the patient) by carefully considering the purpose of the examination. A radiographic method for measuring the rotation of the femur and the tibia, and the patellar translation was developed and applied to healthy volunteers. The introduced patellar variables have yielded new insights into the complex sequence of motions between the femur, tibia, and patella. The patients with a dislocating patella were subdivided into one 'clean' group of spontaneous dislocations and one group with various traumas in the history, which thus resulted in two groups with distinct radiographic differences. The Q-angle was decreased in knees that had suffered dislocations, and the traditional surgical treatment with a further reduction of the Q-angle must be challenged. The use of clinical measurements of the Q-angle was not an optimal way to evaluate the mechanical alignment in the patellofemoral joint under physiological conditions. In this study, we have

  1. Acceptability, Precision and Accuracy of 3D Photonic Scanning for Measurement of Body Shape in a Multi-Ethnic Sample of Children Aged 5-11 Years: The SLIC Study.

    Directory of Open Access Journals (Sweden)

    Jonathan C K Wells

    Full Text Available Information on body size and shape is used to interpret many aspects of physiology, including nutritional status, cardio-metabolic risk and lung function. Such data have traditionally been obtained through manual anthropometry, which becomes time-consuming when many measurements are required. 3D photonic scanning (3D-PS of body surface topography represents an alternative digital technique, previously applied successfully in large studies of adults. The acceptability, precision and accuracy of 3D-PS in young children have not been assessed.We attempted to obtain data on girth, width and depth of the chest and waist, and girth of the knee and calf, manually and by 3D-PS in a multi-ethnic sample of 1484 children aged 5-11 years. The rate of 3D-PS success, and reasons for failure, were documented. Precision and accuracy of 3D-PS were assessed relative to manual measurements using the methods of Bland and Altman.Manual measurements were successful in all cases. Although 97.4% of children agreed to undergo 3D-PS, successful scans were only obtained in 70.7% of these. Unsuccessful scans were primarily due to body movement, or inability of the software to extract shape outputs. The odds of scan failure, and the underlying reason, differed by age, size and ethnicity. 3D-PS measurements tended to be greater than those obtained manually (p 0.90 for most outcomes.3D-PS is acceptable in children aged ≥ 5 years, though with current hardware/software, and body movement artefacts, approximately one third of scans may be unsuccessful. The technique had poorer technical success than manual measurements, and had poorer precision when the measurements were viable. Compared to manual measurements, 3D-PS showed modest average biases but acceptable limits of agreement for large surveys, and little evidence that bias varied substantially with size. Most of the issues we identified could be addressed through further technological development.

  2. Precision and accuracy control of dose calibrator: CAPINTEC CRC 12 in laboratory for radiopharmacy of Nuclear Medicine Institute of Sucre, Bolivia; Control de precision y exactitud del calibrador de dosis: CAPINTEC CRC 12 del Laboratorio de Radiofarmacia del Instituto de Medicina Nuclear Sucre

    Energy Technology Data Exchange (ETDEWEB)

    Huanca Sardinas, E; Castro Sacci, O; Torrez Cabero, M; Vasquez Ibanez, M.R; Zambrana Zelada, AJ., E-mail: nuclear_sre@entelnet.bo, E-mail: ehuancasardinas@hotmail.com, E-mail: marcetorrez@hotmail.com, E-mail: maritavas@yahoo.es, E-mail: alfzambrana@gmail.com [Universidad Mayor Real y Pontifica de San Francisco Xavier de Chuquisaca, Sucre (Bolivia, Plurinational State of). Radiofarmacia - Instituto de Medicina Nuclear de Sucre. Hospital Santa Barbara

    2013-11-01

    The dose calibrator is one of the indispensable tools in radiopharmacy laboratories of a nuclear medicine department also is mandated to provide accurate readings. A very high doses produce unnecessary radiation exposure to the patient or a very low dose, prolong the acquisition time of the studies affecting the quality of the image. In the present work we did a retrospective analysis of the results of quality checks performed at precision accuracy of the Gauge CRC12 CAPINTEC dose calibrator over a period of 16 years, using sealed certified sources with low power, medium and high: Ba{sup 133} , Cs{sup 137} , Co{sup 60} and Co{sup 57}. The results showed that the lowest standard deviation value was 0.17 for Ba133, relative to Co{sup 57} of 2.97 in the control of accuracy. Accuracy over control values were also lower standard deviation for Ba{sup 133} 1.00, relative to Co{sup 57} 10.06. Being stated that the CRC12 CAPINTEC activimeter reliability is acceptable during the reporting period and under the conditions indicated. Therefore, we continue to make these quality control procedures and the professional must feel confident that the measurements obtained with it are reliable.

  3. Precision electron polarimetry

    International Nuclear Information System (INIS)

    Chudakov, E.

    2013-01-01

    A new generation of precise Parity-Violating experiments will require a sub-percent accuracy of electron beam polarimetry. Compton polarimetry can provide such accuracy at high energies, but at a few hundred MeV the small analyzing power limits the sensitivity. Mo/ller polarimetry provides a high analyzing power independent on the beam energy, but is limited by the properties of the polarized targets commonly used. Options for precision polarimetry at 300 MeV will be discussed, in particular a proposal to use ultra-cold atomic hydrogen traps to provide a 100%-polarized electron target for Mo/ller polarimetry

  4. Why precision?

    Energy Technology Data Exchange (ETDEWEB)

    Bluemlein, Johannes

    2012-05-15

    Precision measurements together with exact theoretical calculations have led to steady progress in fundamental physics. A brief survey is given on recent developments and current achievements in the field of perturbative precision calculations in the Standard Model of the Elementary Particles and their application in current high energy collider data analyses.

  5. Why precision?

    International Nuclear Information System (INIS)

    Bluemlein, Johannes

    2012-05-01

    Precision measurements together with exact theoretical calculations have led to steady progress in fundamental physics. A brief survey is given on recent developments and current achievements in the field of perturbative precision calculations in the Standard Model of the Elementary Particles and their application in current high energy collider data analyses.

  6. Precision digital control systems

    Science.gov (United States)

    Vyskub, V. G.; Rozov, B. S.; Savelev, V. I.

    This book is concerned with the characteristics of digital control systems of great accuracy. A classification of such systems is considered along with aspects of stabilization, programmable control applications, digital tracking systems and servomechanisms, and precision systems for the control of a scanning laser beam. Other topics explored are related to systems of proportional control, linear devices and methods for increasing precision, approaches for further decreasing the response time in the case of high-speed operation, possibilities for the implementation of a logical control law, and methods for the study of precision digital control systems. A description is presented of precision automatic control systems which make use of electronic computers, taking into account the existing possibilities for an employment of computers in automatic control systems, approaches and studies required for including a computer in such control systems, and an analysis of the structure of automatic control systems with computers. Attention is also given to functional blocks in the considered systems.

  7. Improved patient repositioning accuracy by integrating an additional jaw fixation into a high precision face mask system in stereotactic radiotherapy of the head; Verbesserte lagerungsreproduzierbarkeit eines nichtinvasiven hochpraezisionsmaskensystems in der stereotaktischen Radiotherapie durch eine integrierte kieferfixierung

    Energy Technology Data Exchange (ETDEWEB)

    Lopatta, E.; Liesenfeld, S.M.; Bank, P.; Guenther, R.; Wiezorek, T.; Wendt, T.G. [Klinik fuer Radiologie, Abt. fuer Strahlentherapie, Friedrich-Schiller-Univ. Jena (Germany); Wurm, R. [Campus Charite Mitte, Klinik fuer Strahlentherapie, Berlin (Germany)

    2003-08-01

    Background: For high precision radiotherapy of the neurocranium a precise, reproducible positioning technique is the basic pre-requisite. The aim of this study was to assess the influence of a modification of the commercially available stereotactical BrainLab {sup trademark} -head mask system on accuracy in patient positioning during fractionated radiotherapy. Material and Methods: 29 patients were treated with stereotactic radiotherapy of the head. Immobilization was provided by a two layer thermoplastic mask system (BrainLab trademark). 18 of these patients received an additional custom made fixation either of the upper jaw (OKF) or of the mandibula (UKF). The positioning accuracy was assessed by measurements of the shifting of anatomical landmarks in relation to therigid mask system on biplanar simulator films using a digital imaging system. Before each measurement a fine adjustment of the simulator to an optical ring system was performed. The reference radiographs were done just before CT-planning. During a 2-7 weeks lasting course of radiotherapy displacement measurements in relation to the reference images for all three dimensions (z, y and x) were done once a week. In 29 patients 844 measurements were analyzed. Results: An additional jaw fixation improves the reproducibility of patient positioning significantly in all three spatial dimensions. The standard deviation in lateral direction (x) was 0.6 mm with jaw fixation vs. 0.7 mm without jaw fixation (p < 0.001); in longitudinal direction (z) (measured in 0 radiographs) 0.5 mm vs. 1.3 mm (p < 0.001); in longitudinal direction measured in 90 (orig.) [German] Hintergrund: Eine Grundvoraussetzung fuer die Praezisionsbestrahlung im Bereich des Neurokraniums ist eine genaue, reproduzierbare Lagerungstechnik. Die vorliegende Arbeit untersucht den Einfluss einer Modifikation am kommerziell erhaeltlichen stereotaktischen BrainLab trademark -Kopfmaskensystem auf die Lagerungsgenauigkeit waehrend einer fraktionierten

  8. Accuracy and precision of polar lower stratospheric temperatures from reanalyses evaluated from A-Train CALIOP and MLS, COSMIC GPS RO, and the equilibrium thermodynamics of supercooled ternary solutions and ice clouds

    Science.gov (United States)

    Lambert, Alyn; Santee, Michelle L.

    2018-02-01

    We investigate the accuracy and precision of polar lower stratospheric temperatures (100-10 hPa during 2008-2013) reported in several contemporary reanalysis datasets comprising two versions of the Modern-Era Retrospective analysis for Research and Applications (MERRA and MERRA-2), the Japanese 55-year Reanalysis (JRA-55), the European Centre for Medium-Range Weather Forecasts (ECMWF) interim reanalysis (ERA-I), and the National Oceanic and Atmospheric Administration (NOAA) National Centers for Environmental Prediction (NCEP) Climate Forecast System Reanalysis (NCEP-CFSR). We also include the Goddard Earth Observing System model version 5.9.1 near-real-time analysis (GEOS-5.9.1). Comparisons of these datasets are made with respect to retrieved temperatures from the Aura Microwave Limb Sounder (MLS), Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC) Global Positioning System (GPS) radio occultation (RO) temperatures, and independent absolute temperature references defined by the equilibrium thermodynamics of supercooled ternary solutions (STSs) and ice clouds. Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) observations of polar stratospheric clouds are used to determine the cloud particle types within the Aura MLS geometric field of view. The thermodynamic calculations for STS and the ice frost point use the colocated MLS gas-phase measurements of HNO3 and H2O. The estimated bias and precision for the STS temperature reference, over the 68 to 21 hPa pressure range, are 0.6-1.5 and 0.3-0.6 K, respectively; for the ice temperature reference, they are 0.4 and 0.3 K, respectively. These uncertainties are smaller than those estimated for the retrieved MLS temperatures and also comparable to GPS RO uncertainties (bias 0.7 K) in the same pressure range. We examine a case study of the time-varying temperature structure associated with layered ice clouds formed by orographic gravity waves forced by flow over the Palmer Peninsula and

  9. Application of AFINCH as a tool for evaluating the effects of streamflow-gaging-network size and composition on the accuracy and precision of streamflow estimates at ungaged locations in the southeast Lake Michigan hydrologic subregion

    Science.gov (United States)

    Koltun, G.F.; Holtschlag, David J.

    2010-01-01

    Bootstrapping techniques employing random subsampling were used with the AFINCH (Analysis of Flows In Networks of CHannels) model to gain insights into the effects of variation in streamflow-gaging-network size and composition on the accuracy and precision of streamflow estimates at ungaged locations in the 0405 (Southeast Lake Michigan) hydrologic subregion. AFINCH uses stepwise-regression techniques to estimate monthly water yields from catchments based on geospatial-climate and land-cover data in combination with available streamflow and water-use data. Calculations are performed on a hydrologic-subregion scale for each catchment and stream reach contained in a National Hydrography Dataset Plus (NHDPlus) subregion. Water yields from contributing catchments are multiplied by catchment areas and resulting flow values are accumulated to compute streamflows in stream reaches which are referred to as flow lines. AFINCH imposes constraints on water yields to ensure that observed streamflows are conserved at gaged locations.  Data from the 0405 hydrologic subregion (referred to as Southeast Lake Michigan) were used for the analyses. Daily streamflow data were measured in the subregion for 1 or more years at a total of 75 streamflow-gaging stations during the analysis period which spanned water years 1971–2003. The number of streamflow gages in operation each year during the analysis period ranged from 42 to 56 and averaged 47. Six sets (one set for each censoring level), each composed of 30 random subsets of the 75 streamflow gages, were created by censoring (removing) approximately 10, 20, 30, 40, 50, and 75 percent of the streamflow gages (the actual percentage of operating streamflow gages censored for each set varied from year to year, and within the year from subset to subset, but averaged approximately the indicated percentages).Streamflow estimates for six flow lines each were aggregated by censoring level, and results were analyzed to assess (a) how the

  10. Precision translator

    Science.gov (United States)

    Reedy, Robert P.; Crawford, Daniel W.

    1984-01-01

    A precision translator for focusing a beam of light on the end of a glass fiber which includes two turning fork-like members rigidly connected to each other. These members have two prongs each with its separation adjusted by a screw, thereby adjusting the orthogonal positioning of a glass fiber attached to one of the members. This translator is made of simple parts with capability to keep adjustment even in condition of rough handling.

  11. Precision Cosmology

    Science.gov (United States)

    Jones, Bernard J. T.

    2017-04-01

    Preface; Notation and conventions; Part I. 100 Years of Cosmology: 1. Emerging cosmology; 2. The cosmic expansion; 3. The cosmic microwave background; 4. Recent cosmology; Part II. Newtonian Cosmology: 5. Newtonian cosmology; 6. Dark energy cosmological models; 7. The early universe; 8. The inhomogeneous universe; 9. The inflationary universe; Part III. Relativistic Cosmology: 10. Minkowski space; 11. The energy momentum tensor; 12. General relativity; 13. Space-time geometry and calculus; 14. The Einstein field equations; 15. Solutions of the Einstein equations; 16. The Robertson-Walker solution; 17. Congruences, curvature and Raychaudhuri; 18. Observing and measuring the universe; Part IV. The Physics of Matter and Radiation: 19. Physics of the CMB radiation; 20. Recombination of the primeval plasma; 21. CMB polarisation; 22. CMB anisotropy; Part V. Precision Tools for Precision Cosmology: 23. Likelihood; 24. Frequentist hypothesis testing; 25. Statistical inference: Bayesian; 26. CMB data processing; 27. Parametrising the universe; 28. Precision cosmology; 29. Epilogue; Appendix A. SI, CGS and Planck units; Appendix B. Magnitudes and distances; Appendix C. Representing vectors and tensors; Appendix D. The electromagnetic field; Appendix E. Statistical distributions; Appendix F. Functions on a sphere; Appendix G. Acknowledgements; References; Index.

  12. Precision Airdrop (Largage de precision)

    Science.gov (United States)

    2005-12-01

    NAVIGATION TO A PRECISION AIRDROP OVERVIEW RTO-AG-300-V24 2 - 9 the point from various compass headings. As the tests are conducted, the resultant...rate. This approach avoids including a magnetic compass for the heading reference, which has difficulties due to local changes in the magnetic field...Scientifica della Difesa ROYAUME-UNI Via XX Settembre 123 Dstl Knowledge Services ESPAGNE 00187 Roma Information Centre, Building 247 SDG TECEN / DGAM

  13. A modified precise integration method based on Magnus expansion for transient response analysis of time varying dynamical structure

    International Nuclear Information System (INIS)

    Yue, Cong; Ren, Xingmin; Yang, Yongfeng; Deng, Wangqun

    2016-01-01

    This paper provides a precise and efficacious methodology for manifesting forced vibration response with respect to the time-variant linear rotational structure subjected to unbalanced excitation. A modified algorithm based on time step precise integration method and Magnus expansion is developed for instantaneous dynamic problems. The iterative solution is achieved by the ideology of transition and dimensional increment matrix. Numerical examples on a typical accelerating rotation system considering gyroscopic moment and mass unbalance force comparatively demonstrate the validity, effectiveness and accuracy with Newmark-β method. It is shown that the proposed algorithm has high accuracy without loss efficiency.

  14. Precision synchrotron radiation detectors

    International Nuclear Information System (INIS)

    Levi, M.; Rouse, F.; Butler, J.

    1989-03-01

    Precision detectors to measure synchrotron radiation beam positions have been designed and installed as part of beam energy spectrometers at the Stanford Linear Collider (SLC). The distance between pairs of synchrotron radiation beams is measured absolutely to better than 28 /mu/m on a pulse-to-pulse basis. This contributes less than 5 MeV to the error in the measurement of SLC beam energies (approximately 50 GeV). A system of high-resolution video cameras viewing precisely-aligned fiducial wire arrays overlaying phosphorescent screens has achieved this accuracy. Also, detectors of synchrotron radiation using the charge developed by the ejection of Compton-recoil electrons from an array of fine wires are being developed. 4 refs., 5 figs., 1 tab

  15. Ultra-precision bearings

    CERN Document Server

    Wardle, F

    2015-01-01

    Ultra-precision bearings can achieve extreme accuracy of rotation, making them ideal for use in numerous applications across a variety of fields, including hard disk drives, roundness measuring machines and optical scanners. Ultraprecision Bearings provides a detailed review of the different types of bearing and their properties, as well as an analysis of the factors that influence motion error, stiffness and damping. Following an introduction to basic principles of motion error, each chapter of the book is then devoted to the basic principles and properties of a specific type of bearin

  16. Accuracy and precision of gravitational-wave models of inspiraling neutron star-black hole binaries with spin: Comparison with matter-free numerical relativity in the low-frequency regime

    Science.gov (United States)

    Bhagwat, Swetha; Kumar, Prayush; Barkett, Kevin; Afshari, Nousha; Brown, Duncan A.; Lovelace, Geoffrey; Scheel, Mark A.; Szilagyi, Bela; LIGO Collaboration

    2016-03-01

    Detection of gravitational wave involves extracting extremely weak signal from noisy data and their detection depends crucially on the accuracy of the signal models. The most accurate models of compact binary coalescence are known to come from solving the Einstein's equation numerically without any approximations. However, this is computationally formidable. As a more practical alternative, several analytic or semi analytic approximations are developed to model these waveforms. However, the work of Nitz et al. (2013) demonstrated that there is disagreement between these models. We present a careful follow up study on accuracies of different waveform families for spinning black-hole neutron star binaries, in context of both detection and parameter estimation and find that SEOBNRv2 to be the most faithful model. Post Newtonian models can be used for detection but we find that they could lead to large parameter bias. Supported by National Science Foundation (NSF) Awards No. PHY-1404395 and No. AST-1333142.

  17. Quality control on the accuracy of the total Beta activity index in different sample matrices water; Control de calidad en la precision del indice de actividad beta total en diferentes matrices de muestras de aguas

    Energy Technology Data Exchange (ETDEWEB)

    Pujol, L.; Pablo, M. A. de; Payeras, J.

    2013-07-01

    The standard ISO/IEC 17025:2005 of general requirements for the technical competence of testing and calibration laboratories, provides that a laboratory shall have quality control procedures for monitoring the validity of tests and calibrations ago. In this paper, the experience of Isotopic Applications Laboratory (CEDEX) in controlling the accuracy rate of total beta activity in samples of drinking water, inland waters and marine waters is presented. (Author)

  18. STANFORD (SLAC): Precision electroweak result

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    Precision testing of the electroweak sector of the Standard Model has intensified with the recent publication* of results from the SLD collaboration's 1993 run on the Stanford Linear Collider, SLC. Using a highly polarized electron beam colliding with an unpolarized positron beam, SLD physicists measured the left-right asymmetry at the Z boson resonance with dramatically improved accuracy over 1992

  19. Overlay accuracy fundamentals

    Science.gov (United States)

    Kandel, Daniel; Levinski, Vladimir; Sapiens, Noam; Cohen, Guy; Amit, Eran; Klein, Dana; Vakshtein, Irina

    2012-03-01

    Currently, the performance of overlay metrology is evaluated mainly based on random error contributions such as precision and TIS variability. With the expected shrinkage of the overlay metrology budget to DBO (1st order diffraction based overlay). It is demonstrated that the sensitivity of DBO to overlay mark asymmetry is larger than the sensitivity of imaging overlay. Finally, we show that a recently developed measurement quality metric serves as a valuable tool for improving overlay metrology accuracy. Simulation results demonstrate that the accuracy of imaging overlay can be improved significantly by recipe setup optimized using the quality metric. We conclude that imaging overlay metrology, complemented by appropriate use of measurement quality metric, results in optimal overlay accuracy.

  20. The impact of different cone beam computed tomography and multi-slice computed tomography scan parameters on virtual three-dimensional model accuracy using a highly precise ex vivo evaluation method.

    Science.gov (United States)

    Matta, Ragai-Edward; von Wilmowsky, Cornelius; Neuhuber, Winfried; Lell, Michael; Neukam, Friedrich W; Adler, Werner; Wichmann, Manfred; Bergauer, Bastian

    2016-05-01

    Multi-slice computed tomography (MSCT) and cone beam computed tomography (CBCT) are indispensable imaging techniques in advanced medicine. The possibility of creating virtual and corporal three-dimensional (3D) models enables detailed planning in craniofacial and oral surgery. The objective of this study was to evaluate the impact of different scan protocols for CBCT and MSCT on virtual 3D model accuracy using a software-based evaluation method that excludes human measurement errors. MSCT and CBCT scans with different manufacturers' predefined scan protocols were obtained from a human lower jaw and were superimposed with a master model generated by an optical scan of an industrial noncontact scanner. To determine the accuracy, the mean and standard deviations were calculated, and t-tests were used for comparisons between the different settings. Averaged over 10 repeated X-ray scans per method and 19 measurement points per scan (n = 190), it was found that the MSCT scan protocol 140 kV delivered the most accurate virtual 3D model, with a mean deviation of 0.106 mm compared to the master model. Only the CBCT scans with 0.2-voxel resolution delivered a similar accurate 3D model (mean deviation 0.119 mm). Within the limitations of this study, it was demonstrated that the accuracy of a 3D model of the lower jaw depends on the protocol used for MSCT and CBCT scans. Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  1. Sensing Characteristics of A Precision Aligner Using Moire Gratings for Precision Alignment System

    Institute of Scientific and Technical Information of China (English)

    ZHOU Lizhong; Hideo Furuhashi; Yoshiyuki Uchida

    2001-01-01

    Sensing characteristics of a precision aligner using moire gratings for precision alignment sysem has been investigated. A differential moire alignment system and a modified alignment system were used. The influence of the setting accuracy of the gap length and inclination of gratings on the alignment accuracy has been studied experimentally and theoretically. Setting accuracy of the gap length less than 2.5μm is required in modified moire alignment. There is no influence of the gap length on the alignment accuracy in the differential alignment system. The inclination affects alignment accuracies in both differential and modified moire alignment systems.

  2. EDITORIAL: Precision proteins Precision proteins

    Science.gov (United States)

    Demming, Anna

    2010-06-01

    Since the birth of modern day medicine, during the times of Hippocrates in ancient Greece, the profession has developed from the rudimentary classification of disease into a rigorous science with an inspiring capability to treat and cure. Scientific methodology has distilled clinical diagnostic tools from the early arts of prognosis, which used to rely as much on revelation and prophecy, as intuition and judgement [1]. Over the past decade, research into the interactions between proteins and nanosystems has provided some ingenious and apt techniques for delving into the intricacies of anatomical systems. In vivo biosensing has emerged as a vibrant field of research, as much of medical diagnosis relies on the detection of substances or an imbalance in the chemicals in the body. The inherent properties of nanoscale structures, such as cantilevers, make them well suited to biosensing applications that demand the detection of molecules at very low concentrations. Measurable deflections in cantilevers functionalised with antibodies provide quantitative indicators of the presence of specific antigens when the two react. Such developments have roused mounting interest in the interactions of proteins with nanostructures, such as carbon nanotubes [3], which have demonstrated great potential as generic biomarkers. Plasmonic properties are also being exploited in sensing applications, such as the molecular sentinel recently devised by researchers in the US. The device uses the plasmonic properties of a silver nanoparticle linked to a Raman labelled hairpin DNA probe to signal changes in the probe geometry resulting from interactions with substances in the environment. Success stories so far include the detection of two specific genes associated with breast cancer [4]. A greater understanding of how RNA interference regulates gene expression has highlighted the potential of using this natural process as another agent for combating disease in personalized medicine. However, the

  3. Study of methodology diversification in diagnostics

    International Nuclear Information System (INIS)

    Suda, Kazunori; Yonekawa, Tsuyoshi; Yoshikawa, Shinji; Hasegawa, Makoto

    1999-03-01

    There are several research activities to enhance safety and reliability of nuclear power plant operation and maintenance. We are developing a concept of an autonomous operation system where the role of operators is replaced with artificial intelligence. The purpose of the study described in this report is to develop a operator support system in abnormal plant situations. Conventionally, diagnostic modules based on individual methodology such as expert system have been developed and verified. In this report, methodology diversification is considered to integrate diagnostic modules which performance are confirmed using information processing technique. Technical issues to be considered in diagnostic methodology diversification are; 1)reliability of input data, 2)diversification of knowledge models, algorithms and reasoning schemes, 3)mutual complement and robustness. The diagnostic module utilizing the different approaches defined along with strategy of diversification was evaluated using fast breeder plant simulator. As a result, we confirmed that any singular diagnostic module can not meet accuracy criteria for the entire set of anomaly events. In contrast with this, we confirmed that every abnormality could be precisely diagnosed by a mutual combination. In other words, legitimacy of approach selected by strategy of diversification was shown, and methodology diversification attained clear efficiency for abnormal diagnosis. It has been also confirmed that the diversified diagnostic system implemented in this study is able to maintain its accuracy even in case that encountered scale of abnormality is different from reference cases embedded in the knowledge base. (author)

  4. Introduction to precise numerical methods

    CERN Document Server

    Aberth, Oliver

    2007-01-01

    Precise numerical analysis may be defined as the study of computer methods for solving mathematical problems either exactly or to prescribed accuracy. This book explains how precise numerical analysis is constructed. The book also provides exercises which illustrate points from the text and references for the methods presented. All disc-based content for this title is now available on the Web. · Clearer, simpler descriptions and explanations ofthe various numerical methods· Two new types of numerical problems; accurately solving partial differential equations with the included software and computing line integrals in the complex plane.

  5. Assessment of historical leak model methodology as applied to the REDOX high-level waste tank SX-108

    International Nuclear Information System (INIS)

    JONES, T.E.

    1999-01-01

    Using the Historical Leak Model approach, the estimated leak rate (and therefore, projected leak volume) for Tank 241-SX-108 could not be reproduced using the data included in the initial document describing the leak methodology. An analysis of parameters impacting tank heat load calculations strongly suggest that the historical tank operating data lack the precision and accuracy required to estimate tank leak volumes using the Historical Leak Model methodology

  6. TH-AB-202-10: Quantifying the Accuracy and Precision of Six Degree-Of-Freedom Motion Estimation for Use in Real-Time Tumor Motion Monitoring During Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J [The University of Sydney, Sydney, New South Wales (Australia); Nguyen, D; O’Brien, R; Keall, P [University of Sydney, Sydney, NSW (Australia); Huang, C [Sydney Medical School, Camperdown (Australia); Caillet, V [The University of Sydney, Sydney, NSW (Australia); Poulsen, P [Aarhus University Hospital, Aarhus (Denmark); Booth, J [Royal North Shore Hospital, Sydney (Australia)

    2016-06-15

    Purpose: Kilovoltage intrafraction monitoring (KIM) scheme has been successfully used to simultaneously monitor 3D tumor motion during radiotherapy. Recently, an iterative closest point (ICP) algorithm was implemented in KIM to also measure rotations about three axes, enabling real-time tracking of tumor motion in six degrees-of-freedom (DoF). This study aims to evaluate the accuracy of the six DoF motion estimates of KIM by comparing it with the corresponding motion (i) measured by the Calypso; and (ii) derived from kV/MV triangulation. Methods: (i) Various motions (static and dynamic) were applied to a CIRS phantom with three embedded electromagnetic transponders (Calypso Medical) using a 5D motion platform (HexaMotion) and a rotating treatment couch while both KIM and Calypso were used to concurrently track the phantom motion in six DoF. (ii) KIM was also used to retrospectively estimate six DoF motion from continuous sets of kV projections of a prostate, implanted with three gold fiducial markers (2 patients with 80 fractions in total), acquired during the treatment. Corresponding motion was obtained from kV/MV triangulation using a closed form least squares method based on three markers’ positions. Only the frames where all three markers were present were used in the analysis. The mean differences between the corresponding motion estimates were calculated for each DoF. Results: Experimental results showed that the mean of absolute differences in six DoF phantom motion measured by Calypso and KIM were within 1.1° and 0.7 mm. kV/MV triangulation derived six DoF prostate tumor better agreed with KIM estimated motion with the mean (s.d.) difference of up to 0.2° (1.36°) and 0.2 (0.25) mm for rotation and translation, respectively. Conclusion: These results suggest that KIM can provide an accurate six DoF intrafraction tumor during radiotherapy.

  7. Mixed-Precision Spectral Deferred Correction: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Grout, Ray W. S.

    2015-09-02

    Convergence of spectral deferred correction (SDC), where low-order time integration methods are used to construct higher-order methods through iterative refinement, can be accelerated in terms of computational effort by using mixed-precision methods. Using ideas from multi-level SDC (in turn based on FAS multigrid ideas), some of the SDC correction sweeps can use function values computed in reduced precision without adversely impacting the accuracy of the final solution. This is particularly beneficial for the performance of combustion solvers such as S3D [6] which require double precision accuracy but are performance limited by the cost of data motion.

  8. Precision titration mini-calorimeter

    International Nuclear Information System (INIS)

    Ensor, D.; Kullberg, L.; Choppin, G.

    1977-01-01

    The design and test of a small volume calorimeter of high precision and simple design is described. The calorimeter operates with solution sample volumes in the range of 3 to 5 ml. The results of experiments on the entropy changes for two standard reactions: (1) reaction of tris(hydroxymethyl)aminomethane with hydrochloric acid and (2) reaction between mercury(II) and bromide ions are reported to confirm the accuracy and overall performance of the calorimeter

  9. Precision and Accuracy of Intercontinental Distance Determinations Using Radio Interferometry.

    Science.gov (United States)

    1983-07-01

    applicsible) Air Forcc Gc.’!physics Laborator - LWG F19628-82-K- 0002 Sc ADDRESS ICity,. State and ZIP Code) 10. SOURCE OF FUNDING NOS. [lanscon AFB, MA...error in the calibration phase, E. Hence E tan-’[( Acsin, s- Acoso )/A ] (3.2.5)4s obs s obs cal and the corrected calibration phase will be given by cal m

  10. Increasing Precision and Accuracy of Laser Isotope Analyser Data

    International Nuclear Information System (INIS)

    Chen, Janet; Mayr, Leopold; Resch, Christian; Dercon, Gerd

    2017-01-01

    Isotope analysis with laser spectroscopy is an emerging technology that is growing in scientific demand. Because this technology allows for real-time, in situ measurements of carbon-13 ("1"3C) and nitrogen-15 ("1"5N) of CO_2, CH_4 and N_2O, it is increasingly being used to monitor fluxes of these greenhouse gases. However, despite its potential to provide robust data to researchers, methods of calibration and data correction are still being developed and refined. Furthermore, standard reference gases are currently not available and researchers must make their own gases to ensure proper calibration and data correction. To improve quality of data and allow for comparison of data between studies, it is essential that standard CO_2, CH_4 and N_2O gases are accessible to researchers.

  11. Precision and accuracy of decay constants and age standards

    Science.gov (United States)

    Villa, I. M.

    2011-12-01

    40 years of round-robin experiments with age standards teach us that systematic errors must be present in at least N-1 labs if participants provide N mutually incompatible data. In EarthTime, the U-Pb community has produced and distributed synthetic solutions with full metrological traceability. Collector linearity is routinely calibrated under variable conditions (e.g. [1]). Instrumental mass fractionation is measured in-run with double spikes (e.g. 233U-236U). Parent-daughter ratios are metrologically traceable, so the full uncertainty budget of a U-Pb age should coincide with interlaboratory uncertainty. TIMS round-robin experiments indeed show a decrease of N towards the ideal value of 1. Comparing 235U-207Pb with 238U-206Pb ages (e.g. [2]) has resulted in a credible re-evaluation of the 235U decay constant, with lower uncertainty than gamma counting. U-Pb microbeam techniques reveal the link petrology-microtextures-microchemistry-isotope record but do not achieve the low uncertainty of TIMS. In the K-Ar community, N is large; interlaboratory bias is > 10 times self-assessed uncertainty. Systematic errors may have analytical and petrological reasons. Metrological traceability is not yet implemented (substantial advance may come from work in progress, e.g. [7]). One of the worst problems is collector stability and linearity. Using electron multipliers (EM) instead of Faraday buckets (FB) reduces both dynamic range and collector linearity. Mass spectrometer backgrounds are never zero; the extent as well as the predictability of their variability must be propagated into the uncertainty evaluation. The high isotope ratio of the atmospheric Ar requires a large dynamic range over which linearity must be demonstrated under all analytical conditions to correctly estimate mass fractionation. The only assessment of EM linearity in Ar analyses [3] points out many fundamental problems; the onus of proof is on every laboratory claiming low uncertainties. Finally, sample size reduction is often associated to reducing clean-up time to increase sample/blank ratio; this may be self-defeating, as "dry blanks" [4] do not represent either the isotopic composition or the amount of Ar released by the sample chamber when exposed to unpurified sample gas. Single grains enhance background and purification problems relative to large sample sizes measured on FB. Petrologically, many natural "standards" are not ideal (e.g. MMhb1 [5], B4M [6]), as their original distributors never conceived petrology as the decisive control on isotope retention. Comparing ever smaller aliquots of unequilibrated minerals causes ever larger age variations. Metrologically traceable synthetic isotope mixtures still lie in the future. Petrological non-ideality of natural standards does not allow a metrological uncertainty budget. Collector behavior, on the contrary, does. Its quantification will, by definition, make true intralaboratory uncertainty greater or equal to interlaboratory bias. [1] Chen J, Wasserburg GJ, 1981. Analyt Chem 53, 2060-2067 [2] Mattinson JM, 2010. Chem Geol 275, 186-198 [3] Turrin B et al, 2010. G-cubed, 11, Q0AA09 [4] Baur H, 1975. PhD thesis, ETH Zürich, No. 6596 [5] Villa IM et al, 1996. Contrib Mineral Petrol 126, 67-80 [6] Villa IM, Heri AR, 2010. AGU abstract V31A-2296 [7] Morgan LE et al, in press. G-cubed, 2011GC003719

  12. Accuracy and Precision of Radioactivity Quantification in Nuclear Medicine Images

    Science.gov (United States)

    Frey, Eric C.; Humm, John L.; Ljungberg, Michael

    2012-01-01

    The ability to reliably quantify activity in nuclear medicine has a number of increasingly important applications. Dosimetry for targeted therapy treatment planning or for approval of new imaging agents requires accurate estimation of the activity in organs, tumors, or voxels at several imaging time points. Another important application is the use of quantitative metrics derived from images, such as the standard uptake value commonly used in positron emission tomography (PET), to diagnose and follow treatment of tumors. These measures require quantification of organ or tumor activities in nuclear medicine images. However, there are a number of physical, patient, and technical factors that limit the quantitative reliability of nuclear medicine images. There have been a large number of improvements in instrumentation, including the development of hybrid single-photon emission computed tomography/computed tomography and PET/computed tomography systems, and reconstruction methods, including the use of statistical iterative reconstruction methods, which have substantially improved the ability to obtain reliable quantitative information from planar, single-photon emission computed tomography, and PET images. PMID:22475429

  13. Quality, precision and accuracy of the maximum No. 40 anemometer

    Energy Technology Data Exchange (ETDEWEB)

    Obermeir, J. [Otech Engineering, Davis, CA (United States); Blittersdorf, D. [NRG Systems Inc., Hinesburg, VT (United States)

    1996-12-31

    This paper synthesizes available calibration data for the Maximum No. 40 anemometer. Despite its long history in the wind industry, controversy surrounds the choice of transfer function for this anemometer. Many users are unaware that recent changes in default transfer functions in data loggers are producing output wind speed differences as large as 7.6%. Comparison of two calibration methods used for large samples of Maximum No. 40 anemometers shows a consistent difference of 4.6% in output speeds. This difference is significantly larger than estimated uncertainty levels. Testing, initially performed to investigate related issues, reveals that Gill and Maximum cup anemometers change their calibration transfer functions significantly when calibrated in the open atmosphere compared with calibration in a laminar wind tunnel. This indicates that atmospheric turbulence changes the calibration transfer function of cup anemometers. These results call into question the suitability of standard wind tunnel calibration testing for cup anemometers. 6 refs., 10 figs., 4 tabs.

  14. Clinical evaluation of the FreeStyle Precision Pro system.

    Science.gov (United States)

    Brazg, Ronald; Hughes, Kristen; Martin, Pamela; Coard, Julie; Toffaletti, John; McDonnell, Elizabeth; Taylor, Elizabeth; Farrell, Lausanne; Patel, Mona; Ward, Jeanne; Chen, Ting; Alva, Shridhara; Ng, Ronald

    2013-06-05

    A new version of international standard (ISO 15197) and CLSI Guideline (POCT12) with more stringent accuracy criteria are near publication. We evaluated the glucose test performance of the FreeStyle Precision Pro system, a new blood glucose monitoring system (BGMS) designed to enhance accuracy for point-of-care testing (POCT). Precision, interference and system accuracy with 503 blood samples from capillary, venous and arterial sources were evaluated in a multicenter study. Study results were analyzed and presented in accordance with the specifications and recommendations of the final draft ISO 15197 and the new POCT12. The FreeStyle Precision Pro system demonstrated acceptable precision (CV FreeStyle Precision Pro system met the tighter accuracy requirements, providing a means for enhancing accuracy for point-of-care blood glucose monitoring. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Radiotherapy of abdomen with precise renal assessment with SPECT/CT imaging (RAPRASI): design and methodology of a prospective trial to improve the understanding of kidney radiation dose response

    International Nuclear Information System (INIS)

    Lopez-Gaitan, Juanita; O’Mara, Brenton; Chu, Julie; Faggian, Jessica; Williams, Luke; Hofman, Michael S; Spry, Nigel A; Ebert, Martin A; Robins, Peter; Boucek, Jan; Leong, Trevor; Willis, David; Bydder, Sean; Podias, Peter; Waters, Gemma

    2013-01-01

    The kidneys are a principal dose-limiting organ in radiotherapy for upper abdominal cancers. The current understanding of kidney radiation dose response is rudimentary. More precise dose-volume response models that allow direct correlation of delivered radiation dose with spatio-temporal changes in kidney function may improve radiotherapy treatment planning for upper-abdominal tumours. Our current understanding of kidney dose response and tolerance is limited and this is hindering efforts to introduce advanced radiotherapy techniques for upper-abdominal cancers, such as intensity-modulated radiotherapy (IMRT). The aim of this study is to utilise radiotherapy and combined anatomical/functional imaging data to allow direct correlation of radiation dose with spatio-temporal changes in kidney function. The data can then be used to develop a more precise dose-volume response model which has the potential to optimise and individualise upper abdominal radiotherapy plans. The Radiotherapy of Abdomen with Precise Renal Assessment with SPECT/CT Imaging (RAPRASI) is an observational clinical research study with participating sites at Sir Charles Gairdner Hospital (SCGH) in Perth, Australia and the Peter MacCallum Cancer Centre (PMCC) in Melbourne, Australia. Eligible patients are those with upper gastrointestinal cancer, without metastatic disease, undergoing conformal radiotherapy that will involve incidental radiation to one or both kidneys. For each patient, total kidney function is being assessed before commencement of radiotherapy treatment and then at 4, 12, 26, 52 and 78 weeks after the first radiotherapy fraction, using two procedures: a Glomerular Filtration Rate (GFR) measurement using the 51 Cr-ethylenediamine tetra-acetic acid (EDTA) clearance; and a regional kidney perfusion measurement assessing renal uptake of 99m Tc-dimercaptosuccinic acid (DMSA), imaged with a Single Photon Emission Computed Tomography / Computed Tomography (SPECT/CT) system. The CT component

  16. Precision siting of a particle accelerator

    International Nuclear Information System (INIS)

    Cintra, Jorge Pimentel

    1996-01-01

    Precise location is a specific survey job that involves a high skilled work to avoid unrecoverable results at the project installation. As a function of the different process stages, different specifications can be applied, invoking different instruments: theodolite, measurement tape, distanciometer, invar wire. This paper, based on experience obtained at the installation of particle accelerator equipment, deals with general principles of precise location: tolerance definitions, increasing accuracy techniques, schedule of locations, sensitivity analysis, quality control methods. (author)

  17. Error and Uncertainty in the Accuracy Assessment of Land Cover Maps

    Science.gov (United States)

    Sarmento, Pedro Alexandre Reis

    Traditionally the accuracy assessment of land cover maps is performed through the comparison of these maps with a reference database, which is intended to represent the "real" land cover, being this comparison reported with the thematic accuracy measures through confusion matrixes. Although, these reference databases are also a representation of reality, containing errors due to the human uncertainty in the assignment of the land cover class that best characterizes a certain area, causing bias in the thematic accuracy measures that are reported to the end users of these maps. The main goal of this dissertation is to develop a methodology that allows the integration of human uncertainty present in reference databases in the accuracy assessment of land cover maps, and analyse the impacts that uncertainty may have in the thematic accuracy measures reported to the end users of land cover maps. The utility of the inclusion of human uncertainty in the accuracy assessment of land cover maps is investigated. Specifically we studied the utility of fuzzy sets theory, more precisely of fuzzy arithmetic, for a better understanding of human uncertainty associated to the elaboration of reference databases, and their impacts in the thematic accuracy measures that are derived from confusion matrixes. For this purpose linguistic values transformed in fuzzy intervals that address the uncertainty in the elaboration of reference databases were used to compute fuzzy confusion matrixes. The proposed methodology is illustrated using a case study in which the accuracy assessment of a land cover map for Continental Portugal derived from Medium Resolution Imaging Spectrometer (MERIS) is made. The obtained results demonstrate that the inclusion of human uncertainty in reference databases provides much more information about the quality of land cover maps, when compared with the traditional approach of accuracy assessment of land cover maps. None

  18. Precision surveying the principles and geomatics practice

    CERN Document Server

    Ogundare, John Olusegun

    2016-01-01

    A comprehensive overview of high precision surveying, including recent developments in geomatics and their applications This book covers advanced precision surveying techniques, their proper use in engineering and geoscience projects, and their importance in the detailed analysis and evaluation of surveying projects. The early chapters review the fundamentals of precision surveying: the types of surveys; survey observations; standards and specifications; and accuracy assessments for angle, distance and position difference measurement systems. The book also covers network design and 3-D coordinating systems before discussing specialized topics such as structural and ground deformation monitoring techniques and analysis, mining surveys, tunneling surveys, and alignment surveys. Precision Surveying: The Principles and Geomatics Practice: * Covers structural and ground deformation monitoring analysis, advanced techniques in mining and tunneling surveys, and high precision alignment of engineering structures *...

  19. High-precision positioning of radar scatterers

    NARCIS (Netherlands)

    Dheenathayalan, P.; Small, D.; Schubert, A.; Hanssen, R.F.

    2016-01-01

    Remote sensing radar satellites cover wide areas and provide spatially dense measurements, with millions of scatterers. Knowledge of the precise position of each radar scatterer is essential to identify the corresponding object and interpret the estimated deformation. The absolute position accuracy

  20. Practical precision measurement

    International Nuclear Information System (INIS)

    Kwak, Ho Chan; Lee, Hui Jun

    1999-01-01

    This book introduces basic knowledge of precision measurement, measurement of length, precision measurement of minor diameter, measurement of angles, measurement of surface roughness, three dimensional measurement, measurement of locations and shapes, measurement of screw, gear testing, cutting tools testing, rolling bearing testing, and measurement of digitalisation. It covers height gauge, how to test surface roughness, measurement of plan and straightness, external and internal thread testing, gear tooth measurement, milling cutter, tab, rotation precision measurement, and optical transducer.

  1. [Precision and personalized medicine].

    Science.gov (United States)

    Sipka, Sándor

    2016-10-01

    The author describes the concept of "personalized medicine" and the newly introduced "precision medicine". "Precision medicine" applies the terms of "phenotype", "endotype" and "biomarker" in order to characterize more precisely the various diseases. Using "biomarkers" the homogeneous type of a disease (a "phenotype") can be divided into subgroups called "endotypes" requiring different forms of treatment and financing. The good results of "precision medicine" have become especially apparent in relation with allergic and autoimmune diseases. The application of this new way of thinking is going to be necessary in Hungary, too, in the near future for participants, controllers and financing boards of healthcare. Orv. Hetil., 2016, 157(44), 1739-1741.

  2. Precision Clock Evaluation Facility

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Tests and evaluates high-precision atomic clocks for spacecraft, ground, and mobile applications. Supports performance evaluation, environmental testing,...

  3. Subdomain Precise Integration Method for Periodic Structures

    Directory of Open Access Journals (Sweden)

    F. Wu

    2014-01-01

    Full Text Available A subdomain precise integration method is developed for the dynamical responses of periodic structures comprising many identical structural cells. The proposed method is based on the precise integration method, the subdomain scheme, and the repeatability of the periodic structures. In the proposed method, each structural cell is seen as a super element that is solved using the precise integration method, considering the repeatability of the structural cells. The computational efforts and the memory size of the proposed method are reduced, while high computational accuracy is achieved. Therefore, the proposed method is particularly suitable to solve the dynamical responses of periodic structures. Two numerical examples are presented to demonstrate the accuracy and efficiency of the proposed method through comparison with the Newmark and Runge-Kutta methods.

  4. CIAU methodology and BEPU applications

    International Nuclear Information System (INIS)

    Petruzzi, A.; D'Auria, F.

    2009-01-01

    Best-Estimate calculation results from complex thermal-hydraulic system codes (like Relap5, Cathare, Athlet, Trace, etc..) are affected by unavoidable approximations that are unpredictable without the use of computational tools that account for the various sources of uncertainty. Therefore the use of best-estimate codes within the reactor technology, either for design or safety purposes, implies understanding and accepting the limitations and the deficiencies of those codes. Uncertainties may have different origins ranging from the approximation of the models, to the approximation of the numerical solution, and to the lack of precision of the values adopted for boundary and initial conditions. The amount of uncertainty that affects a calculation may strongly depend upon the codes and the modeling techniques (i.e. the code's users). A consistent and robust uncertainty methodology must be developed taking into consideration all the above aspects. The CIAU (Code with the capability of Internal Assessment of Uncertainty) and the UMAE (Uncertainty Methodology based on Accuracy Evaluation) methods have been developed by University of Pisa (UNIPI) in the framework of a long lasting research activities started since 80's and involving several researchers. CIAU is extensively discussed in the available technical literature, Refs. [1, 2, 3, 4, 5, 6, 7], and tens of additional relevant papers, that provide comprehensive details about the method, can be found in the bibliography lists of the above references. Therefore, the present paper supplies only 'spot-information' about CIAU and focuses mostly on the applications to some cases of industrial interest. In particular the application of CIAU to the OECD BEMUSE (Best Estimate Methods Uncertainty and Sensitivity Evaluation, [8, 9]) project is discussed and a critical comparison respect with other uncertainty methods (in relation to items like: sources of uncertainties, selection of the input parameters and quantification of

  5. Precision machining commercialization

    International Nuclear Information System (INIS)

    1978-01-01

    To accelerate precision machining development so as to realize more of the potential savings within the next few years of known Department of Defense (DOD) part procurement, the Air Force Materials Laboratory (AFML) is sponsoring the Precision Machining Commercialization Project (PMC). PMC is part of the Tri-Service Precision Machine Tool Program of the DOD Manufacturing Technology Five-Year Plan. The technical resources supporting PMC are provided under sponsorship of the Department of Energy (DOE). The goal of PMC is to minimize precision machining development time and cost risk for interested vendors. PMC will do this by making available the high precision machining technology as developed in two DOE contractor facilities, the Lawrence Livermore Laboratory of the University of California and the Union Carbide Corporation, Nuclear Division, Y-12 Plant, at Oak Ridge, Tennessee

  6. Accuracy of radiocarbon analyses at ANTARES

    Energy Technology Data Exchange (ETDEWEB)

    Lawson, E M; Fink, D; Hotchkis, M; Hua, Q; Jacobsen, G; Smith, A M; Tuniz, C [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

    1997-12-31

    Accuracy in Accelerator Mass Spectroscopy (AMS) measurements, as distinct from precision, requires the application of a number of corrections. Most of these are well known except in extreme circumstances and AMS can deliver radiocarbon results which are both precise and accurate in the 0.5 to 1.0% range. The corrections involved in obtaining final radiocarbon ages are discussed. 3 refs., 1 tab.

  7. Accuracy of radiocarbon analyses at ANTARES

    Energy Technology Data Exchange (ETDEWEB)

    Lawson, E.M.; Fink, D.; Hotchkis, M.; Hua, Q.; Jacobsen, G.; Smith, A.M.; Tuniz, C. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

    1996-12-31

    Accuracy in Accelerator Mass Spectroscopy (AMS) measurements, as distinct from precision, requires the application of a number of corrections. Most of these are well known except in extreme circumstances and AMS can deliver radiocarbon results which are both precise and accurate in the 0.5 to 1.0% range. The corrections involved in obtaining final radiocarbon ages are discussed. 3 refs., 1 tab.

  8. Light Microscopy at Maximal Precision

    Directory of Open Access Journals (Sweden)

    Matthew Bierbaum

    2017-10-01

    Full Text Available Microscopy is the workhorse of the physical and life sciences, producing crisp images of everything from atoms to cells well beyond the capabilities of the human eye. However, the analysis of these images is frequently little more accurate than manual marking. Here, we revolutionize the analysis of microscopy images, extracting all the useful information theoretically contained in a complex microscope image. Using a generic, methodological approach, we extract the information by fitting experimental images with a detailed optical model of the microscope, a method we call parameter extraction from reconstructing images (PERI. As a proof of principle, we demonstrate this approach with a confocal image of colloidal spheres, improving measurements of particle positions and radii by 10–100 times over current methods and attaining the maximum possible accuracy. With this unprecedented accuracy, we measure nanometer-scale colloidal interactions in dense suspensions solely with light microscopy, a previously impossible feat. Our approach is generic and applicable to imaging methods from brightfield to electron microscopy, where we expect accuracies of 1 nm and 0.1 pm, respectively.

  9. Light Microscopy at Maximal Precision

    Science.gov (United States)

    Bierbaum, Matthew; Leahy, Brian D.; Alemi, Alexander A.; Cohen, Itai; Sethna, James P.

    2017-10-01

    Microscopy is the workhorse of the physical and life sciences, producing crisp images of everything from atoms to cells well beyond the capabilities of the human eye. However, the analysis of these images is frequently little more accurate than manual marking. Here, we revolutionize the analysis of microscopy images, extracting all the useful information theoretically contained in a complex microscope image. Using a generic, methodological approach, we extract the information by fitting experimental images with a detailed optical model of the microscope, a method we call parameter extraction from reconstructing images (PERI). As a proof of principle, we demonstrate this approach with a confocal image of colloidal spheres, improving measurements of particle positions and radii by 10-100 times over current methods and attaining the maximum possible accuracy. With this unprecedented accuracy, we measure nanometer-scale colloidal interactions in dense suspensions solely with light microscopy, a previously impossible feat. Our approach is generic and applicable to imaging methods from brightfield to electron microscopy, where we expect accuracies of 1 nm and 0.1 pm, respectively.

  10. System and method for high precision isotope ratio destructive analysis

    Science.gov (United States)

    Bushaw, Bruce A; Anheier, Norman C; Phillips, Jon R

    2013-07-02

    A system and process are disclosed that provide high accuracy and high precision destructive analysis measurements for isotope ratio determination of relative isotope abundance distributions in liquids, solids, and particulate samples. The invention utilizes a collinear probe beam to interrogate a laser ablated plume. This invention provides enhanced single-shot detection sensitivity approaching the femtogram range, and isotope ratios that can be determined at approximately 1% or better precision and accuracy (relative standard deviation).

  11. submitter LEP precision results

    CERN Document Server

    Kawamoto, T

    2001-01-01

    Precision measurements at LEP are reviewed, with main focus on the electroweak measurements and tests of the Standard Model. Constraints placed by the LEP measurements on possible new physics are also discussed.

  12. Description of precision colorimeter

    OpenAIRE

    Campos Acosta, Joaquín; Pons Aglio, Alicia; Corróns, Antonio

    1987-01-01

    Describes the use of a fully automatic, computer-controlled absolute spectroradiometer as a precision colorimeter. The chromaticity coordinates of several types of light sources have been obtained with this measurement system.

  13. NCI Precision Medicine

    Science.gov (United States)

    This illustration represents the National Cancer Institute’s support of research to improve precision medicine in cancer treatment, in which unique therapies treat an individual’s cancer based on specific genetic abnormalities of that person’s tumor.

  14. Laser precision microfabrication

    CERN Document Server

    Sugioka, Koji; Pique, Alberto

    2010-01-01

    Miniaturization and high precision are rapidly becoming a requirement for many industrial processes and products. As a result, there is greater interest in the use of laser microfabrication technology to achieve these goals. This book composed of 16 chapters covers all the topics of laser precision processing from fundamental aspects to industrial applications to both inorganic and biological materials. It reviews the sate of the art of research and technological development in the area of laser processing.

  15. Avaliação da acurácia de uma barra de luz utilizada na agricultura de precisão, em relação ao marcador de espuma Evaluation of the accuracy of a light bar used in precision farming compared to a foam marker

    Directory of Open Access Journals (Sweden)

    Fábio H. R. Baio

    2001-05-01

    Full Text Available Alguns equipamentos utilizados na agricultura de precisão têm, por finalidade, a melhoria das condições operacionais. A barra de luz é um equipamento utilizado para a orientação de um veículo em faixas adjacentes, diminuindo a sobreposição da operação agrícola entre passadas consecutivas e otimizando a eficiência da aplicação agrícola. O presente trabalho teve por objetivo a determinação da acurácia da barra de luz em relação ao marcador de espuma e a verificação da adaptação dos operadores à nova tecnologia. Para tanto, foram realizados dois ensaios em locais distintos, com operadores diferentes e foram comparados os erros de sobreposição e falhas nas passadas adjacentes de um pulverizador automotriz. Ocorreu alta adaptação dos operadores à nova tecnologia, devido a uma facilidade operacional maior em relação ao marcador de espuma. Concluiu-se que o marcador de espuma pode ser substituído pela barra de luz na aplicação de defensivos agrícolas.Some equipments are used in precision farming to improve operational conditions. A light bar is an equipment used to guide a vehicle in adjacent bands, reducing the overlap of the parallel swathing and optimizing the efficiency of the agricultural application. The objective of this work was to determine the accuracy of a light bar compared to a foam marker, and to verify the adaptation of the operators to this new technology. Experiments were conducted at two different places with several operators. The overlap errors and missed applications in the parallel swathing system were compared for both systems. There was a high adaptability of the operators to the light bar since this system was easier to operate than the foam marker. It was concluded that the light bar for the application of agricultural chemicals could replace the foam marker.

  16. PRECISE - pregabalin in addition to usual care: Statistical analysis plan

    NARCIS (Netherlands)

    S. Mathieson (Stephanie); L. Billot (Laurent); C. Maher (Chris); A.J. McLachlan (Andrew J.); J. Latimer (Jane); B.W. Koes (Bart); M.J. Hancock (Mark J.); I. Harris (Ian); R.O. Day (Richard O.); J. Pik (Justin); S. Jan (Stephen); C.-W.C. Lin (Chung-Wei Christine)

    2016-01-01

    textabstractBackground: Sciatica is a severe, disabling condition that lacks high quality evidence for effective treatment strategies. This a priori statistical analysis plan describes the methodology of analysis for the PRECISE study. Methods/design: PRECISE is a prospectively registered, double

  17. Rigorous accuracy assessment for 3D reconstruction using time-series Dual Fluoroscopy (DF) image pairs

    Science.gov (United States)

    Al-Durgham, Kaleel; Lichti, Derek D.; Kuntze, Gregor; Ronsky, Janet

    2017-06-01

    High-speed biplanar videoradiography, or clinically referred to as dual fluoroscopy (DF), imaging systems are being used increasingly for skeletal kinematics analysis. Typically, a DF system comprises two X-ray sources, two image intensifiers and two high-speed video cameras. The combination of these elements provides time-series image pairs of articulating bones of a joint, which permits the measurement of bony rotation and translation in 3D at high temporal resolution (e.g., 120-250 Hz). Assessment of the accuracy of 3D measurements derived from DF imaging has been the subject of recent research efforts by several groups, however with methodological limitations. This paper presents a novel and simple accuracy assessment procedure based on using precise photogrammetric tools. We address the fundamental photogrammetry principles for the accuracy evaluation of an imaging system. Bundle adjustment with selfcalibration is used for the estimation of the system parameters. The bundle adjustment calibration uses an appropriate sensor model and applies free-network constraints and relative orientation stability constraints for a precise estimation of the system parameters. A photogrammetric intersection of time-series image pairs is used for the 3D reconstruction of a rotating planar object. A point-based registration method is used to combine the 3D coordinates from the intersection and independently surveyed coordinates. The final DF accuracy measure is reported as the distance between 3D coordinates from image intersection and the independently surveyed coordinates. The accuracy assessment procedure is designed to evaluate the accuracy over the full DF image format and a wide range of object rotation. Experiment of reconstruction of a rotating planar object reported an average positional error of 0.44 +/- 0.2 mm in the derived 3D coordinates (minimum 0.05 and maximum 1.2 mm).

  18. 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....... 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...

  19. Precision Experiments at LEP

    CERN Document Server

    de Boer, Wim

    2015-01-01

    The Large Electron Positron Collider (LEP) established the Standard Model (SM) of particle physics with unprecedented precision, including all its radiative corrections. These led to predictions for the masses of the top quark and Higgs boson, which were beautifully confirmed later on. After these precision measurements the Nobel Prize in Physics was awarded in 1999 jointly to 't Hooft and Veltman "for elucidating the quantum structure of electroweak interactions in physics". Another hallmark of the LEP results were the precise measurements of the gauge coupling constants, which excluded unification of the forces within the SM, but allowed unification within the supersymmetric extension of the SM. This increased the interest in Supersymmetry (SUSY) and Grand Unified Theories, especially since the SM has no candidate for the elusive dark matter, while Supersymmetry provides an excellent candidate for dark matter. In addition, Supersymmetry removes the quadratic divergencies of the SM and {\\it predicts} the Hig...

  20. Precision muonium spectroscopy

    International Nuclear Information System (INIS)

    Jungmann, Klaus P.

    2016-01-01

    The muonium atom is the purely leptonic bound state of a positive muon and an electron. It has a lifetime of 2.2 µs. The absence of any known internal structure provides for precision experiments to test fundamental physics theories and to determine accurate values of fundamental constants. In particular ground state hyperfine structure transitions can be measured by microwave spectroscopy to deliver the muon magnetic moment. The frequency of the 1s–2s transition in the hydrogen-like atom can be determined with laser spectroscopy to obtain the muon mass. With such measurements fundamental physical interactions, in particular quantum electrodynamics, can also be tested at highest precision. The results are important input parameters for experiments on the muon magnetic anomaly. The simplicity of the atom enables further precise experiments, such as a search for muonium–antimuonium conversion for testing charged lepton number conservation and searches for possible antigravity of muons and dark matter. (author)

  1. Precision genome editing

    DEFF Research Database (Denmark)

    Steentoft, Catharina; Bennett, Eric P; Schjoldager, Katrine Ter-Borch Gram

    2014-01-01

    Precise and stable gene editing in mammalian cell lines has until recently been hampered by the lack of efficient targeting methods. While different gene silencing strategies have had tremendous impact on many biological fields, they have generally not been applied with wide success in the field...... of glycobiology, primarily due to their low efficiencies, with resultant failure to impose substantial phenotypic consequences upon the final glycosylation products. Here, we review novel nuclease-based precision genome editing techniques enabling efficient and stable gene editing, including gene disruption...... by introducing single or double-stranded breaks at a defined genomic sequence. We here compare and contrast the different techniques and summarize their current applications, highlighting cases from the field of glycobiology as well as pointing to future opportunities. The emerging potential of precision gene...

  2. A passion for precision

    CERN Multimedia

    CERN. Geneva. Audiovisual Unit

    2006-01-01

    For more than three decades, the quest for ever higher precision in laser spectroscopy of the simple hydrogen atom has inspired many advances in laser, optical, and spectroscopic techniques, culminating in femtosecond laser optical frequency combs as perhaps the most precise measuring tools known to man. Applications range from optical atomic clocks and tests of QED and relativity to searches for time variations of fundamental constants. Recent experiments are extending frequency comb techniques into the extreme ultraviolet. Laser frequency combs can also control the electric field of ultrashort light pulses, creating powerful new tools for the emerging field of attosecond science.

  3. Improving Precision of Types

    DEFF Research Database (Denmark)

    Winther, Johnni

    Types in programming languages provide a powerful tool for the programmer to document the code so that a large aspect of the intent can not only be presented to fellow programmers but also be checked automatically by compilers. The precision with which types model the behavior of programs...... is crucial to the quality of these automated checks, and in this thesis we present three different improvements to the precision of types in three different aspects of the Java programming language. First we show how to extend the type system in Java with a new type which enables the detection of unintended...

  4. Precise Orbit Determination of GPS Satellites Using Phase Observables

    Directory of Open Access Journals (Sweden)

    Myung-Kook Jee

    1997-12-01

    Full Text Available The accuracy of user position by GPS is heavily dependent upon the accuracy of satellite position which is usually transmitted to GPS users in radio signals. The real-time satellite position information directly obtained from broadcast ephimerides has the accuracy of 3 x 10 meters which is very unsatisfactory to measure 100km baseline to the accuracy of less than a few mili-meters. There are globally at present seven orbit analysis centers capable of generating precise GPS ephimerides and their orbit quality is of the order of about 10cm. Therefore, precise orbit model and phase processing technique were reviewed and consequently precise GPS ephimerides were produced after processing the phase observables of 28 global GPS stations for 1 day. Initial 6 orbit parameters and 2 solar radiation coefficients were estimated using batch least square algorithm and the final results were compared with the orbit of IGS, the International GPS Service for Geodynamics.

  5. Microhartree precision in density functional theory calculations

    Science.gov (United States)

    Gulans, Andris; Kozhevnikov, Anton; Draxl, Claudia

    2018-04-01

    To address ultimate precision in density functional theory calculations we employ the full-potential linearized augmented plane-wave + local-orbital (LAPW + lo) method and justify its usage as a benchmark method. LAPW + lo and two completely unrelated numerical approaches, the multiresolution analysis (MRA) and the linear combination of atomic orbitals, yield total energies of atoms with mean deviations of 0.9 and 0.2 μ Ha , respectively. Spectacular agreement with the MRA is reached also for total and atomization energies of the G2-1 set consisting of 55 molecules. With the example of α iron we demonstrate the capability of LAPW + lo to reach μ Ha /atom precision also for periodic systems, which allows also for the distinction between the numerical precision and the accuracy of a given functional.

  6. DOTD standards for GPS data collection accuracy : [tech summary].

    Science.gov (United States)

    2015-09-01

    Positional data collection e orts performed by personnel and contractors of the Louisiana Department of Transportation and Development : (DOTD) requires a reliable and consistent measurement framework for ensuring accuracy and precision. Global Na...

  7. Modified sine bar device measures small angles with high accuracy

    Science.gov (United States)

    Thekaekara, M.

    1968-01-01

    Modified sine bar device measures small angles with enough accuracy to calibrate precision optical autocollimators. The sine bar is a massive bar of steel supported by two cylindrical rods at one end and one at the other.

  8. Precision physics at LHC

    International Nuclear Information System (INIS)

    Hinchliffe, I.

    1997-05-01

    In this talk the author gives a brief survey of some physics topics that will be addressed by the Large Hadron Collider currently under construction at CERN. Instead of discussing the reach of this machine for new physics, the author gives examples of the types of precision measurements that might be made if new physics is discovered

  9. Precision Muonium Spectroscopy

    NARCIS (Netherlands)

    Jungmann, Klaus P.

    2016-01-01

    The muonium atom is the purely leptonic bound state of a positive muon and an electron. It has a lifetime of 2.2 mu s. The absence of any known internal structure provides for precision experiments to test fundamental physics theories and to determine accurate values of fundamental constants. In

  10. What is precision medicine?

    Science.gov (United States)

    König, Inke R; Fuchs, Oliver; Hansen, Gesine; von Mutius, Erika; Kopp, Matthias V

    2017-10-01

    The term "precision medicine" has become very popular over recent years, fuelled by scientific as well as political perspectives. Despite its popularity, its exact meaning, and how it is different from other popular terms such as "stratified medicine", "targeted therapy" or "deep phenotyping" remains unclear. Commonly applied definitions focus on the stratification of patients, sometimes referred to as a novel taxonomy, and this is derived using large-scale data including clinical, lifestyle, genetic and further biomarker information, thus going beyond the classical "signs-and-symptoms" approach.While these aspects are relevant, this description leaves open a number of questions. For example, when does precision medicine begin? In which way does the stratification of patients translate into better healthcare? And can precision medicine be viewed as the end-point of a novel stratification of patients, as implied, or is it rather a greater whole?To clarify this, the aim of this paper is to provide a more comprehensive definition that focuses on precision medicine as a process. It will be shown that this proposed framework incorporates the derivation of novel taxonomies and their role in healthcare as part of the cycle, but also covers related terms. Copyright ©ERS 2017.

  11. On methodology

    DEFF Research Database (Denmark)

    Cheesman, Robin; Faraone, Roque

    2002-01-01

    This is an English version of the methodology chapter in the authors' book "El caso Berríos: Estudio sobre información errónea, desinformación y manipulación de la opinión pública".......This is an English version of the methodology chapter in the authors' book "El caso Berríos: Estudio sobre información errónea, desinformación y manipulación de la opinión pública"....

  12. Registration accuracy and quality of real-life images.

    Directory of Open Access Journals (Sweden)

    Wei-Yen Hsu

    Full Text Available BACKGROUND: A common registration problem for the application of consumer device is to align all the acquired image sequences into a complete scene. Image alignment requires a registration algorithm that will compensate as much as possible for geometric variability among images. However, images captured views from a real scene usually produce different distortions. Some are derived from the optic characteristics of image sensors, and others are caused by the specific scenes and objects. METHODOLOGY/PRINCIPAL FINDINGS: An image registration algorithm considering the perspective projection is proposed for the application of consumer devices in this study. It exploits a multiresolution wavelet-based method to extract significant features. An analytic differential approach is then proposed to achieve fast convergence of point matching. Finally, the registration accuracy is further refined to obtain subpixel precision by a feature-based modified Levenberg-Marquardt method. Due to its feature-based and nonlinear characteristic, it converges considerably faster than most other methods. In addition, vignette compensation and color difference adjustment are also performed to further improve the quality of registration results. CONCLUSIONS/SIGNIFICANCE: The performance of the proposed method is evaluated by testing the synthetic and real images acquired by a hand-held digital still camera and in comparison with two registration techniques in terms of the squared sum of intensity differences (SSD and correlation coefficient (CC. The results indicate that the proposed method is promising in registration accuracy and quality, which are statistically significantly better than other two approaches.

  13. Introduction to precision machine design and error assessment

    CERN Document Server

    Mekid, Samir

    2008-01-01

    While ultra-precision machines are now achieving sub-nanometer accuracy, unique challenges continue to arise due to their tight specifications. Written to meet the growing needs of mechanical engineers and other professionals to understand these specialized design process issues, Introduction to Precision Machine Design and Error Assessment places a particular focus on the errors associated with precision design, machine diagnostics, error modeling, and error compensation. Error Assessment and ControlThe book begins with a brief overview of precision engineering and applications before introdu

  14. A passion for precision

    CERN Multimedia

    CERN. Geneva

    2006-01-01

    For more than three decades, the quest for ever higher precision in laser spectroscopy of the simple hydrogen atom has inspired many advances in laser, optical, and spectroscopic techniques, culminating in femtosecond laser optical frequency combs  as perhaps the most precise measuring tools known to man. Applications range from optical atomic clocks and tests of QED and relativity to searches for time variations of fundamental constants. Recent experiments are extending frequency comb techniques into the extreme ultraviolet. Laser frequency combs can also control the electric field of ultrashort light pulses, creating powerful new tools for the emerging field of attosecond science.Organiser(s): L. Alvarez-Gaume / PH-THNote: * Tea & coffee will be served at 16:00.

  15. Quad precision delay generator

    International Nuclear Information System (INIS)

    Krishnan, Shanti; Gopalakrishnan, K.R.; Marballi, K.R.

    1997-01-01

    A Quad Precision Delay Generator delays a digital edge by a programmed amount of time, varying from nanoseconds to microseconds. The output of this generator has an amplitude of the order of tens of volts and rise time of the order of nanoseconds. This was specifically designed and developed to meet the stringent requirements of the plasma focus experiments. Plasma focus is a laboratory device for producing and studying nuclear fusion reactions in hot deuterium plasma. 3 figs

  16. Verification of Positional Accuracy of ZVS3003 Geodetic Control ...

    African Journals Online (AJOL)

    The International GPS Service (IGS) has provided GPS orbit products to the scientific community with increased precision and timeliness. Many users interested in geodetic positioning have adopted the IGS precise orbits to achieve centimeter level accuracy and ensure long-term reference frame stability. Positioning with ...

  17. The Precision Field Lysimeter Concept

    Science.gov (United States)

    Fank, J.

    2009-04-01

    The understanding and interpretation of leaching processes have improved significantly during the past decades. Unlike laboratory experiments, which are mostly performed under very controlled conditions (e.g. homogeneous, uniform packing of pre-treated test material, saturated steady-state flow conditions, and controlled uniform hydraulic conditions), lysimeter experiments generally simulate actual field conditions. Lysimeters may be classified according to different criteria such as type of soil block used (monolithic or reconstructed), drainage (drainage by gravity or vacuum or a water table may be maintained), or weighing or non-weighing lysimeters. In 2004 experimental investigations have been set up to assess the impact of different farming systems on groundwater quality of the shallow floodplain aquifer of the river Mur in Wagna (Styria, Austria). The sediment is characterized by a thin layer (30 - 100 cm) of sandy Dystric Cambisol and underlying gravel and sand. Three precisely weighing equilibrium tension block lysimeters have been installed in agricultural test fields to compare water flow and solute transport under (i) organic farming, (ii) conventional low input farming and (iii) extensification by mulching grass. Specific monitoring equipment is used to reduce the well known shortcomings of lysimeter investigations: The lysimeter core is excavated as an undisturbed monolithic block (circular, 1 m2 surface area, 2 m depth) to prevent destruction of the natural soil structure, and pore system. Tracing experiments have been achieved to investigate the occurrence of artificial preferential flow and transport along the walls of the lysimeters. The results show that such effects can be neglected. Precisely weighing load cells are used to constantly determine the weight loss of the lysimeter due to evaporation and transpiration and to measure different forms of precipitation. The accuracy of the weighing apparatus is 0.05 kg, or 0.05 mm water equivalent

  18. 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.

  19. Using a hybrid methodology of dasyametric mapping and data ...

    African Journals Online (AJOL)

    Using a hybrid methodology of dasyametric mapping and data interpolation techniques ... AFRICAN JOURNALS ONLINE (AJOL) · Journals · Advanced Search ... the value and accuracy of the developed methodology is that of the 2011 census ...

  20. Methodological guidelines

    International Nuclear Information System (INIS)

    Halsnaes, K.; Callaway, J.M.; Meyer, H.J.

    1999-01-01

    The guideline document establishes a general overview of the main components of climate change mitigation assessment. This includes an outline of key economic concepts, scenario structure, common assumptions, modelling tools and country study assumptions. The guidelines are supported by Handbook Reports that contain more detailed specifications of calculation standards, input assumptions and available tools. The major objectives of the project have been provided a methodology, an implementing framework and a reporting system which countries can follow in meeting their future reporting obligations under the FCCC and for GEF enabling activities. The project builds upon the methodology development and application in the UNEP National Abatement Coasting Studies (UNEP, 1994a). The various elements provide countries with a road map for conducting climate change mitigation studies and submitting national reports as required by the FCCC. (au) 121 refs

  1. Methodological guidelines

    Energy Technology Data Exchange (ETDEWEB)

    Halsnaes, K.; Callaway, J.M.; Meyer, H.J.

    1999-04-01

    The guideline document establishes a general overview of the main components of climate change mitigation assessment. This includes an outline of key economic concepts, scenario structure, common assumptions, modelling tools and country study assumptions. The guidelines are supported by Handbook Reports that contain more detailed specifications of calculation standards, input assumptions and available tools. The major objectives of the project have been provided a methodology, an implementing framework and a reporting system which countries can follow in meeting their future reporting obligations under the FCCC and for GEF enabling activities. The project builds upon the methodology development and application in the UNEP National Abatement Coasting Studies (UNEP, 1994a). The various elements provide countries with a road map for conducting climate change mitigation studies and submitting national reports as required by the FCCC. (au) 121 refs.

  2. Precision pharmacology for Alzheimer's disease.

    Science.gov (United States)

    Hampel, Harald; Vergallo, Andrea; Aguilar, Lisi Flores; Benda, Norbert; Broich, Karl; Cuello, A Claudio; Cummings, Jeffrey; Dubois, Bruno; Federoff, Howard J; Fiandaca, Massimo; Genthon, Remy; Haberkamp, Marion; Karran, Eric; Mapstone, Mark; Perry, George; Schneider, Lon S; Welikovitch, Lindsay A; Woodcock, Janet; Baldacci, Filippo; Lista, Simone

    2018-04-01

    disease-modifying pathway-based targeted therapies. PP is based on an exploratory and integrative strategy to complex diseases such as brain proteinopathies including AD, aimed at identifying simultaneous aberrant molecular pathways and predicting their temporal impact on the systems levels. The depiction of pathway-based molecular signatures of complex diseases contributes to the accurate and mechanistic stratification of distinct subcohorts of individuals at the earliest compensatory stage when treatment intervention may reverse, stop, or delay the disease. In addition, individualized drug selection may optimize treatment safety by decreasing risk and amplitude of side effects and adverse reactions. From a methodological point of view, comprehensive "omics"-based biomarkers will guide the exploration of spatio-temporal systems-wide morpho-functional shifts along the continuum of AD pathophysiology, from adaptation to irreversible failure. The Alzheimer Precision Medicine Initiative (APMI) and the APMI cohort program (APMI-CP) have commenced to facilitate a paradigm shift towards effective drug discovery and development in AD. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. Precision in harsh environments

    OpenAIRE

    French, P.; Krijnen, G.; Roozeboom, F.

    2016-01-01

    Microsystems are increasingly being applied in harsh and/or inaccessible environments, but many markets expect the same level of functionality for long periods of time. Harsh environments cover areas that can be subjected to high temperature, (bio)-chemical and mechanical disturbances, electromagnetic noise, radiation, or high vacuum. In the field of actuators, the devices must maintain stringent accuracy specifications for displacement, force, and response times, among others. These new requ...

  4. Tidal current energy potential of Nalón river estuary assessment using a high precision flow model

    Science.gov (United States)

    Badano, Nicolás; Valdés, Rodolfo Espina; Álvarez, Eduardo Álvarez

    2018-05-01

    Obtaining energy from tide currents in onshore locations is of great interest due to the proximity to the points of consumption. This opens the door to the feasibility of new installations based on hydrokinetic microturbines even in zones of moderate speed. In this context, the accuracy of energy predictions based on hydrodynamic models is of paramount importance. This research presents a high precision methodology based on a multidimensional hydrodynamic model that is used to study the energetic potential in estuaries. Moreover, it is able to estimate the flow variations caused by microturbine installations. The paper also shows the results obtained from the application of the methodology in a study of the Nalón river mouth (Asturias, Spain).

  5. Precision electroweak measurements

    International Nuclear Information System (INIS)

    Demarteau, M.

    1996-11-01

    Recent electroweak precision measurements fro e + e - and p anti p colliders are presented. Some emphasis is placed on the recent developments in the heavy flavor sector. The measurements are compared to predictions from the Standard Model of electroweak interactions. All results are found to be consistent with the Standard Model. The indirect constraint on the top quark mass from all measurements is in excellent agreement with the direct m t measurements. Using the world's electroweak data in conjunction with the current measurement of the top quark mass, the constraints on the Higgs' mass are discussed

  6. Electroweak precision tests

    International Nuclear Information System (INIS)

    Monteil, St.

    2009-12-01

    This document aims at summarizing a dozen of years of the author's research in High Energy Physics, in particular dealing with precision tests of the electroweak theory. Parity violating asymmetries measurements at LEP with the ALEPH detector together with global consistency checks of the Kobayashi-Maskawa paradigm within the CKM-fitter group are gathered in the first part of the document. The second part deals with the unpublished instrumental work about the design, tests, productions and commissioning of the elements of the Pre-Shower detector of the LHCb spectrometer at LHC. Physics perspectives with LHCb are eventually discussed as a conclusion. (author)

  7. Revolutionizing radiographic diagnostic accuracy in periodontics

    Directory of Open Access Journals (Sweden)

    Brijesh Sharma

    2016-01-01

    Full Text Available Effective diagnostic accuracy has in some way been the missing link between periodontal diagnosis and treatment. Most of the clinicians rely on the conventional two-dimensional (2D radiographs. But being a 2D image, it has its own limitations. 2D images at times can give an incomplete picture about the severity or type of disease and can further affect the treatment plan. Cone beam computed tomography (CBCT has a better potential for detecting periodontal bone defects with accuracy. The purpose here is to describe how CBCT imaging is beneficial in accurate diagnosis and will lead to a precise treatment plan.

  8. Five critical elements to ensure the precision medicine.

    Science.gov (United States)

    Chen, Chengshui; He, Mingyan; Zhu, Yichun; Shi, Lin; Wang, Xiangdong

    2015-06-01

    The precision medicine as a new emerging area and therapeutic strategy has occurred and was practiced in the individual and brought unexpected successes, and gained high attentions from professional and social aspects as a new path to improve the treatment and prognosis of patients. There will be a number of new components to appear or be discovered, of which clinical bioinformatics integrates clinical phenotypes and informatics with bioinformatics, computational science, mathematics, and systems biology. In addition to those tools, precision medicine calls more accurate and repeatable methodologies for the identification and validation of gene discovery. Precision medicine will bring more new therapeutic strategies, drug discovery and development, and gene-oriented treatment. There is an urgent need to identify and validate disease-specific, mechanism-based, or epigenetics-dependent biomarkers to monitor precision medicine, and develop "precision" regulations to guard the application of precision medicine.

  9. Surgical accuracy of three-dimensional virtual planning

    DEFF Research Database (Denmark)

    Stokbro, Kasper; Aagaard, Esben; Torkov, Peter

    2016-01-01

    This retrospective study evaluated the precision and positional accuracy of different orthognathic procedures following virtual surgical planning in 30 patients. To date, no studies of three-dimensional virtual surgical planning have evaluated the influence of segmentation on positional accuracy...... and transverse expansion. Furthermore, only a few have evaluated the precision and accuracy of genioplasty in placement of the chin segment. The virtual surgical plan was compared with the postsurgical outcome by using three linear and three rotational measurements. The influence of maxillary segmentation...

  10. Precision lifetime measurements

    International Nuclear Information System (INIS)

    Tanner, C.E.

    1994-01-01

    Precision measurements of atomic lifetimes provide important information necessary for testing atomic theory. The authors employ resonant laser excitation of a fast atomic beam to measure excited state lifetimes by observing the decay-in-flight of the emitted fluorescence. A similar technique was used by Gaupp, et al., who reported measurements with precisions of less than 0.2%. Their program includes lifetime measurements of the low lying p states in alkali and alkali like systems. Motivation for this work comes from a need to test the atomic many-body-perturbation theory (MBPT) that is necessary for interpretation of parity nonconservation experiments in atomic cesium. The authors have measured the cesium 6p 2 P 1/2 and 6p 2 P 3/2 state lifetimes to be 34.934±0.094 ns and 30.499±0.070 ns respectively. With minor changes to the apparatus, they have extended their measurements to include the lithium 2p 2 P 1/2 and 2p 2 P 3/2 states

  11. Fundamentals of precision medicine

    Science.gov (United States)

    Divaris, Kimon

    2018-01-01

    Imagine a world where clinicians make accurate diagnoses and provide targeted therapies to their patients according to well-defined, biologically-informed disease subtypes, accounting for individual differences in genetic make-up, behaviors, cultures, lifestyles and the environment. This is not as utopic as it may seem. Relatively recent advances in science and technology have led to an explosion of new information on what underlies health and what constitutes disease. These novel insights emanate from studies of the human genome and microbiome, their associated transcriptomes, proteomes and metabolomes, as well as epigenomics and exposomics—such ‘omics data can now be generated at unprecedented depth and scale, and at rapidly decreasing cost. Making sense and integrating these fundamental information domains to transform health care and improve health remains a challenge—an ambitious, laudable and high-yield goal. Precision dentistry is no longer a distant vision; it is becoming part of the rapidly evolving present. Insights from studies of the human genome and microbiome, their associated transcriptomes, proteomes and metabolomes, and epigenomics and exposomics have reached an unprecedented depth and scale. Much more needs to be done, however, for the realization of precision medicine in the oral health domain. PMID:29227115

  12. Precision measurements in supersymmetry

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Johnathan Lee [Stanford Univ., CA (United States)

    1995-05-01

    Supersymmetry is a promising framework in which to explore extensions of the standard model. If candidates for supersymmetric particles are found, precision measurements of their properties will then be of paramount importance. The prospects for such measurements and their implications are the subject of this thesis. If charginos are produced at the LEP II collider, they are likely to be one of the few available supersymmetric signals for many years. The author considers the possibility of determining fundamental supersymmetry parameters in such a scenario. The study is complicated by the dependence of observables on a large number of these parameters. He proposes a straightforward procedure for disentangling these dependences and demonstrate its effectiveness by presenting a number of case studies at representative points in parameter space. In addition to determining the properties of supersymmetric particles, precision measurements may also be used to establish that newly-discovered particles are, in fact, supersymmetric. Supersymmetry predicts quantitative relations among the couplings and masses of superparticles. The author discusses tests of such relations at a future e{sup +}e{sup {minus}} linear collider, using measurements that exploit the availability of polarizable beams. Stringent tests of supersymmetry from chargino production are demonstrated in two representative cases, and fermion and neutralino processes are also discussed.

  13. Precision muon physics

    Science.gov (United States)

    Gorringe, T. P.; Hertzog, D. W.

    2015-09-01

    The muon is playing a unique role in sub-atomic physics. Studies of muon decay both determine the overall strength and establish the chiral structure of weak interactions, as well as setting extraordinary limits on charged-lepton-flavor-violating processes. Measurements of the muon's anomalous magnetic moment offer singular sensitivity to the completeness of the standard model and the predictions of many speculative theories. Spectroscopy of muonium and muonic atoms gives unmatched determinations of fundamental quantities including the magnetic moment ratio μμ /μp, lepton mass ratio mμ /me, and proton charge radius rp. Also, muon capture experiments are exploring elusive features of weak interactions involving nucleons and nuclei. We will review the experimental landscape of contemporary high-precision and high-sensitivity experiments with muons. One focus is the novel methods and ingenious techniques that achieve such precision and sensitivity in recent, present, and planned experiments. Another focus is the uncommonly broad and topical range of questions in atomic, nuclear and particle physics that such experiments explore.

  14. Precision Joining Center

    Science.gov (United States)

    Powell, J. W.; Westphal, D. A.

    1991-08-01

    A workshop to obtain input from industry on the establishment of the Precision Joining Center (PJC) was held on July 10-12, 1991. The PJC is a center for training Joining Technologists in advanced joining techniques and concepts in order to promote the competitiveness of U.S. industry. The center will be established as part of the DOE Defense Programs Technology Commercialization Initiative, and operated by EG&G Rocky Flats in cooperation with the American Welding Society and the Colorado School of Mines Center for Welding and Joining Research. The overall objectives of the workshop were to validate the need for a Joining Technologists to fill the gap between the welding operator and the welding engineer, and to assure that the PJC will train individuals to satisfy that need. The consensus of the workshop participants was that the Joining Technologist is a necessary position in industry, and is currently used, with some variation, by many companies. It was agreed that the PJC core curriculum, as presented, would produce a Joining Technologist of value to industries that use precision joining techniques. The advantage of the PJC would be to train the Joining Technologist much more quickly and more completely. The proposed emphasis of the PJC curriculum on equipment intensive and hands-on training was judged to be essential.

  15. MIRD methodology

    International Nuclear Information System (INIS)

    Rojo, Ana M.; Gomez Parada, Ines

    2004-01-01

    The MIRD (Medical Internal Radiation Dose) system was established by the Society of Nuclear Medicine of USA in 1960 to assist the medical community in the estimation of the dose in organs and tissues due to the incorporation of radioactive materials. Since then, 'MIRD Dose Estimate Report' (from the 1 to 12) and 'Pamphlets', of great utility for the dose calculations, were published. The MIRD system was planned essentially for the calculation of doses received by the patients during nuclear medicine diagnostic procedures. The MIRD methodology for the absorbed doses calculations in different tissues is explained

  16. PSA methodology

    Energy Technology Data Exchange (ETDEWEB)

    Magne, L

    1997-12-31

    The purpose of this text is first to ask a certain number of questions on the methods related to PSAs. Notably we will explore the positioning of the French methodological approach - as applied in the EPS 1300{sup 1} and EPS 900{sup 2} PSAs - compared to other approaches (Part One). This reflection leads to more general reflection: what contents, for what PSA? This is why, in Part Two, we will try to offer a framework for definition of the criteria a PSA should satisfy to meet the clearly identified needs. Finally, Part Three will quickly summarize the questions approached in the first two parts, as an introduction to the debate. 15 refs.

  17. PSA methodology

    International Nuclear Information System (INIS)

    Magne, L.

    1996-01-01

    The purpose of this text is first to ask a certain number of questions on the methods related to PSAs. Notably we will explore the positioning of the French methodological approach - as applied in the EPS 1300 1 and EPS 900 2 PSAs - compared to other approaches (Part One). This reflection leads to more general reflection: what contents, for what PSA? This is why, in Part Two, we will try to offer a framework for definition of the criteria a PSA should satisfy to meet the clearly identified needs. Finally, Part Three will quickly summarize the questions approached in the first two parts, as an introduction to the debate. 15 refs

  18. Parton distributions from high-precision collider data

    Energy Technology Data Exchange (ETDEWEB)

    Ball, Richard D.; Del Debbio, Luigi; Groth-Merrild, Patrick [University of Edinburgh, The Higgs Centre for Theoretical Physics, Edinburgh (United Kingdom); Bertone, Valerio; Hartland, Nathan P.; Rojo, Juan [VU University, Department of Physics and Astronomy, Amsterdam (Netherlands); Nikhef Theory Group, Amsterdam (Netherlands); Carrazza, Stefano [CERN, Theoretical Physics Department, Geneva (Switzerland); Forte, Stefano [Universita di Milano, Tif Lab, Dipartimento di Fisica, Milano (Italy); INFN, Sezione di Milano, Milano (Italy); Guffanti, Alberto [Universita di Torino, Dipartimento di Fisica, Turin (Italy); INFN, Sezione di Torino, Turin (Italy); Kassabov, Zahari [Universita di Milano, Tif Lab, Dipartimento di Fisica, Milano (Italy); INFN, Sezione di Milano, Milano (Italy); Universita di Torino, Dipartimento di Fisica, Turin (Italy); INFN, Sezione di Torino, Turin (Italy); Latorre, Jose I. [Universitat de Barcelona, Departament de Fisica Quantica i Astrofisica, Barcelona (Spain); National University of Singapore, Center for Quantum Technologies, Singapore (Singapore); Nocera, Emanuele R.; Rottoli, Luca; Slade, Emma [University of Oxford, Rudolf Peierls Centre for Theoretical Physics, Oxford (United Kingdom); Ubiali, Maria [University of Cambridge, Cavendish Laboratory, HEP Group, Cambridge (United Kingdom); Collaboration: NNPDF Collaboration

    2017-10-15

    We present a new set of parton distributions, NNPDF3.1, which updates NNPDF3.0, the first global set of PDFs determined using a methodology validated by a closure test. The update is motivated by recent progress in methodology and available data, and involves both. On the methodological side, we now parametrize and determine the charm PDF alongside the light-quark and gluon ones, thereby increasing from seven to eight the number of independent PDFs. On the data side, we now include the D0 electron and muon W asymmetries from the final Tevatron dataset, the complete LHCb measurements of W and Z production in the forward region at 7 and 8 TeV, and new ATLAS and CMS measurements of inclusive jet and electroweak boson production. We also include for the first time top-quark pair differential distributions and the transverse momentum of the Z bosons from ATLAS and CMS. We investigate the impact of parametrizing charm and provide evidence that the accuracy and stability of the PDFs are thereby improved. We study the impact of the new data by producing a variety of determinations based on reduced datasets. We find that both improvements have a significant impact on the PDFs, with some substantial reductions in uncertainties, but with the new PDFs generally in agreement with the previous set at the one-sigma level. The most significant changes are seen in the light-quark flavor separation, and in increased precision in the determination of the gluon. We explore the implications of NNPDF3.1 for LHC phenomenology at Run II, compare with recent LHC measurements at 13 TeV, provide updated predictions for Higgs production cross-sections and discuss the strangeness and charm content of the proton in light of our improved dataset and methodology. The NNPDF3.1 PDFs are delivered for the first time both as Hessian sets, and as optimized Monte Carlo sets with a compressed number of replicas. (orig.)

  19. Precision contact level gauge

    International Nuclear Information System (INIS)

    Krejci, M.; Pilat, M.; Stulik, P.

    1977-01-01

    Equipment was developed measuring the heavy water level in the TR-0 reactor core within an accuracy of several hundredths of a millimeter in a range of around 3.5 m and at a temperature of up to 90 degC. The equipment uses a vibrating needle contact as a high sensitivity level gauge and a servomechanical system with a motion screw carrying the gauge for monitoring and measuring the level in the desired range. The advantage of the unique level gauge consists in that that the transducer converts the measured level position to an electric signal, ie., pulse width, with high sensitivity and without hysteresis. (Kr)

  20. The PPP Precision Analysis Based on BDS Regional Navigation System

    Directory of Open Access Journals (Sweden)

    ZHU Yongxing

    2015-04-01

    Full Text Available BeiDou navigation satellite system(BDS has opened service in most of the Asia-Pacific region, it offers the possibility to break the technological monopoly of GPS in the field of high-precision applications, so its performance of precise point positioning (PPP has been a great concern. Firstly, the constellation of BeiDou regional navigation system and BDS/GPS tracking network is introduced. Secondly, the precise ephemeris and clock offset accuracy of BeiDou satellite based on domestic tracking network is analyzed. Finally, the static and kinematic PPP accuracy is studied, and compared with the GPS. The actual measured numerical example shows that the static and kinematic PPP based on BDS can achieve centimeter-level and decimeter-level respectively, reaching the current level of GPS precise point positioning.

  1. Precision-Recall-Gain Curves:PR Analysis Done Right

    OpenAIRE

    Flach, Peter; Kull, Meelis

    2015-01-01

    Precision-Recall analysis abounds in applications of binary classification where true negatives do not add value and hence should not affect assessment of the classifier's performance. Perhaps inspired by the many advantages of receiver operating characteristic (ROC) curves and the area under such curves for accuracy-based performance assessment, many researchers have taken to report Precision-Recall (PR) curves and associated areas as performance metric. We demonstrate in this paper that thi...

  2. Reliable low precision simulations in land surface models

    Science.gov (United States)

    Dawson, Andrew; Düben, Peter D.; MacLeod, David A.; Palmer, Tim N.

    2017-12-01

    Weather and climate models must continue to increase in both resolution and complexity in order that forecasts become more accurate and reliable. Moving to lower numerical precision may be an essential tool for coping with the demand for ever increasing model complexity in addition to increasing computing resources. However, there have been some concerns in the weather and climate modelling community over the suitability of lower precision for climate models, particularly for representing processes that change very slowly over long time-scales. These processes are difficult to represent using low precision due to time increments being systematically rounded to zero. Idealised simulations are used to demonstrate that a model of deep soil heat diffusion that fails when run in single precision can be modified to work correctly using low precision, by splitting up the model into a small higher precision part and a low precision part. This strategy retains the computational benefits of reduced precision whilst preserving accuracy. This same technique is also applied to a full complexity land surface model, resulting in rounding errors that are significantly smaller than initial condition and parameter uncertainties. Although lower precision will present some problems for the weather and climate modelling community, many of the problems can likely be overcome using a straightforward and physically motivated application of reduced precision.

  3. Precision time distribution within a deep space communications complex

    Science.gov (United States)

    Curtright, J. B.

    1972-01-01

    The Precision Time Distribution System (PTDS) at the Golstone Deep Space Communications Complex is a practical application of existing technology to the solution of a local problem. The problem was to synchronize four station timing systems to a master source with a relative accuracy consistently and significantly better than 10 microseconds. The solution involved combining a precision timing source, an automatic error detection assembly and a microwave distribution network into an operational system. Upon activation of the completed PTDS two years ago, synchronization accuracy at Goldstone (two station relative) was improved by an order of magnitude. It is felt that the validation of the PTDS mechanization is now completed. Other facilities which have site dispersion and synchronization accuracy requirements similar to Goldstone may find the PTDS mechanization useful in solving their problem. At present, the two station relative synchronization accuracy at Goldstone is better than one microsecond.

  4. Artificial intelligence, physiological genomics, and precision medicine.

    Science.gov (United States)

    Williams, Anna Marie; Liu, Yong; Regner, Kevin R; Jotterand, Fabrice; Liu, Pengyuan; Liang, Mingyu

    2018-04-01

    Big data are a major driver in the development of precision medicine. Efficient analysis methods are needed to transform big data into clinically-actionable knowledge. To accomplish this, many researchers are turning toward machine learning (ML), an approach of artificial intelligence (AI) that utilizes modern algorithms to give computers the ability to learn. Much of the effort to advance ML for precision medicine has been focused on the development and implementation of algorithms and the generation of ever larger quantities of genomic sequence data and electronic health records. However, relevance and accuracy of the data are as important as quantity of data in the advancement of ML for precision medicine. For common diseases, physiological genomic readouts in disease-applicable tissues may be an effective surrogate to measure the effect of genetic and environmental factors and their interactions that underlie disease development and progression. Disease-applicable tissue may be difficult to obtain, but there are important exceptions such as kidney needle biopsy specimens. As AI continues to advance, new analytical approaches, including those that go beyond data correlation, need to be developed and ethical issues of AI need to be addressed. Physiological genomic readouts in disease-relevant tissues, combined with advanced AI, can be a powerful approach for precision medicine for common diseases.

  5. Precision Medicine in Cancer Treatment

    Science.gov (United States)

    Precision medicine helps doctors select cancer treatments that are most likely to help patients based on a genetic understanding of their disease. Learn about the promise of precision medicine and the role it plays in cancer treatment.

  6. Development and Evaluation of a UAV-Photogrammetry System for Precise 3D Environmental Modeling.

    Science.gov (United States)

    Shahbazi, Mozhdeh; Sohn, Gunho; Théau, Jérôme; Menard, Patrick

    2015-10-30

    The specific requirements of UAV-photogrammetry necessitate particular solutions for system development, which have mostly been ignored or not assessed adequately in recent studies. Accordingly, this paper presents the methodological and experimental aspects of correctly implementing a UAV-photogrammetry system. The hardware of the system consists of an electric-powered helicopter, a high-resolution digital camera and an inertial navigation system. The software of the system includes the in-house programs specifically designed for camera calibration, platform calibration, system integration, on-board data acquisition, flight planning and on-the-job self-calibration. The detailed features of the system are discussed, and solutions are proposed in order to enhance the system and its photogrammetric outputs. The developed system is extensively tested for precise modeling of the challenging environment of an open-pit gravel mine. The accuracy of the results is evaluated under various mapping conditions, including direct georeferencing and indirect georeferencing with different numbers, distributions and types of ground control points. Additionally, the effects of imaging configuration and network stability on modeling accuracy are assessed. The experiments demonstrated that 1.55 m horizontal and 3.16 m vertical absolute modeling accuracy could be achieved via direct geo-referencing, which was improved to 0.4 cm and 1.7 cm after indirect geo-referencing.

  7. BIG DATA ANALYTICS AND PRECISION ANIMAL AGRICULTURE SYMPOSIUM: Data to decisions.

    Science.gov (United States)

    White, B J; Amrine, D E; Larson, R L

    2018-04-14

    Big data are frequently used in many facets of business and agronomy to enhance knowledge needed to improve operational decisions. Livestock operations collect data of sufficient quantity to perform predictive analytics. Predictive analytics can be defined as a methodology and suite of data evaluation techniques to generate a prediction for specific target outcomes. The objective of this manuscript is to describe the process of using big data and the predictive analytic framework to create tools to drive decisions in livestock production, health, and welfare. The predictive analytic process involves selecting a target variable, managing the data, partitioning the data, then creating algorithms, refining algorithms, and finally comparing accuracy of the created classifiers. The partitioning of the datasets allows model building and refining to occur prior to testing the predictive accuracy of the model with naive data to evaluate overall accuracy. Many different classification algorithms are available for predictive use and testing multiple algorithms can lead to optimal results. Application of a systematic process for predictive analytics using data that is currently collected or that could be collected on livestock operations will facilitate precision animal management through enhanced livestock operational decisions.

  8. Autocalibration of high precision drift tubes

    International Nuclear Information System (INIS)

    Bacci, C.; Bini, C.; Ciapetti, G.; De Zorzi, G.; Gauzzi, P.; Lacava, F.; Nisati, A.; Pontecorvo, L.; Rosati, S.; Veneziano, S.; Cambiaghi, M.; Casellotti, G.; Conta, C.; Fraternali, M.; Lanza, A.; Livan, M.; Polesello, G.; Rimoldi, A.; Vercesi, V.

    1997-01-01

    We present the results on MDT (monitored drift tubes) autocalibration studies obtained from the analysis of the data collected in Summer 1995 on the H8B Muon Test Beam. In particular we studied the possibility of autocalibration of the MDT using four or three layers of tubes, and we compared the calibration obtained using a precise external tracker with the output of the autocalibration procedure. Results show the feasibility of autocalibration with four and three tubes and the good accuracy of the autocalibration procedure. (orig.)

  9. 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...

  10. Does a Structured Data Collection Form Improve The Accuracy of ...

    African Journals Online (AJOL)

    and multiple etiologies for similar presentation. Standardized forms may harmonize the initial assessment, improve accuracy of diagnosis and enhance outcomes. Objectives: To determine the extent to which use of a structured data collection form (SDCF) affected the diagnostic accuracy of AAP. Methodology: A before and ...

  11. Quantifying the Accuracy of a Diagnostic Test or Marker

    NARCIS (Netherlands)

    Linnet, Kristian; Bossuyt, Patrick M. M.; Moons, Karel G. M.; Reitsma, Johannes B. R.

    2012-01-01

    BACKGROUND: In recent years, increasing focus has been directed to the methodology for evaluating (new) tests or biomarkers. A key step in the evaluation of a diagnostic test is the investigation into its accuracy. CONTENT: We reviewed the literature on how to assess the accuracy of diagnostic

  12. Truss Assembly and Welding by Intelligent Precision Jigging Robots

    Science.gov (United States)

    Komendera, Erik; Dorsey, John T.; Doggett, William R.; Correll, Nikolaus

    2014-01-01

    This paper describes an Intelligent Precision Jigging Robot (IPJR) prototype that enables the precise alignment and welding of titanium space telescope optical benches. The IPJR, equipped with micron accuracy sensors and actuators, worked in tandem with a lower precision remote controlled manipulator. The combined system assembled and welded a 2 m truss from stock titanium components. The calibration of the IPJR, and the difference between the predicted and the truss dimensions as-built, identified additional sources of error that should be addressed in the next generation of IPJRs in 2D and 3D.

  13. High precision anatomy for MEG.

    Science.gov (United States)

    Troebinger, Luzia; López, José David; Lutti, Antoine; Bradbury, David; Bestmann, Sven; Barnes, Gareth

    2014-02-01

    Precise MEG estimates of neuronal current flow are undermined by uncertain knowledge of the head location with respect to the MEG sensors. This is either due to head movements within the scanning session or systematic errors in co-registration to anatomy. Here we show how such errors can be minimized using subject-specific head-casts produced using 3D printing technology. The casts fit the scalp of the subject internally and the inside of the MEG dewar externally, reducing within session and between session head movements. Systematic errors in matching to MRI coordinate system are also reduced through the use of MRI-visible fiducial markers placed on the same cast. Bootstrap estimates of absolute co-registration error were of the order of 1mm. Estimates of relative co-registration error were <1.5mm between sessions. We corroborated these scalp based estimates by looking at the MEG data recorded over a 6month period. We found that the between session sensor variability of the subject's evoked response was of the order of the within session noise, showing no appreciable noise due to between-session movement. Simulations suggest that the between-session sensor level amplitude SNR improved by a factor of 5 over conventional strategies. We show that at this level of coregistration accuracy there is strong evidence for anatomical models based on the individual rather than canonical anatomy; but that this advantage disappears for errors of greater than 5mm. This work paves the way for source reconstruction methods which can exploit very high SNR signals and accurate anatomical models; and also significantly increases the sensitivity of longitudinal studies with MEG. © 2013. Published by Elsevier Inc. All rights reserved.

  14. High precision anatomy for MEG☆

    Science.gov (United States)

    Troebinger, Luzia; López, José David; Lutti, Antoine; Bradbury, David; Bestmann, Sven; Barnes, Gareth

    2014-01-01

    Precise MEG estimates of neuronal current flow are undermined by uncertain knowledge of the head location with respect to the MEG sensors. This is either due to head movements within the scanning session or systematic errors in co-registration to anatomy. Here we show how such errors can be minimized using subject-specific head-casts produced using 3D printing technology. The casts fit the scalp of the subject internally and the inside of the MEG dewar externally, reducing within session and between session head movements. Systematic errors in matching to MRI coordinate system are also reduced through the use of MRI-visible fiducial markers placed on the same cast. Bootstrap estimates of absolute co-registration error were of the order of 1 mm. Estimates of relative co-registration error were < 1.5 mm between sessions. We corroborated these scalp based estimates by looking at the MEG data recorded over a 6 month period. We found that the between session sensor variability of the subject's evoked response was of the order of the within session noise, showing no appreciable noise due to between-session movement. Simulations suggest that the between-session sensor level amplitude SNR improved by a factor of 5 over conventional strategies. We show that at this level of coregistration accuracy there is strong evidence for anatomical models based on the individual rather than canonical anatomy; but that this advantage disappears for errors of greater than 5 mm. This work paves the way for source reconstruction methods which can exploit very high SNR signals and accurate anatomical models; and also significantly increases the sensitivity of longitudinal studies with MEG. PMID:23911673

  15. Precision Medicine in Cardiovascular Diseases

    Directory of Open Access Journals (Sweden)

    Yan Liu

    2017-02-01

    Full Text Available Since President Obama announced the Precision Medicine Initiative in the United States, more and more attention has been paid to precision medicine. However, clinicians have already used it to treat conditions such as cancer. Many cardiovascular diseases have a familial presentation, and genetic variants are associated with the prevention, diagnosis, and treatment of cardiovascular diseases, which are the basis for providing precise care to patients with cardiovascular diseases. Large-scale cohorts and multiomics are critical components of precision medicine. Here we summarize the application of precision medicine to cardiovascular diseases based on cohort and omic studies, and hope to elicit discussion about future health care.

  16. Evaluating measurement accuracy a practical approach

    CERN Document Server

    Rabinovich, Semyon G

    2017-01-01

    This book presents a systematic and comprehensive exposition of the theory of measurement accuracy and provides solutions that fill significant and long-standing gaps in the classical theory. It eliminates the shortcomings of the classical theory by including methods for estimating accuracy of single measurements, the most common type of measurement. The book also develops methods of reduction and enumeration for indirect measurements, which do not require Taylor series and produce a precise solution to this problem. It produces grounded methods and recommendations for summation of errors. The monograph also analyzes and critiques two foundation metrological documents, the International Vocabulary of Metrology (VIM) and the Guide to the Expression of Uncertainty in Measurement (GUM), and discusses directions for their revision. This new edition adds a step-by-step guide on how to evaluate measurement accuracy and recommendations on how to calculate systematic error of multiple measurements. There is also an e...

  17. Precisely predictable Dirac observables

    CERN Document Server

    Cordes, Heinz Otto

    2006-01-01

    This work presents a "Clean Quantum Theory of the Electron", based on Dirac’s equation. "Clean" in the sense of a complete mathematical explanation of the well known paradoxes of Dirac’s theory, and a connection to classical theory, including the motion of a magnetic moment (spin) in the given field, all for a charged particle (of spin ½) moving in a given electromagnetic field. This theory is relativistically covariant, and it may be regarded as a mathematically consistent quantum-mechanical generalization of the classical motion of such a particle, à la Newton and Einstein. Normally, our fields are time-independent, but also discussed is the time-dependent case, where slightly different features prevail. A "Schroedinger particle", such as a light quantum, experiences a very different (time-dependent) "Precise Predictablity of Observables". An attempt is made to compare both cases. There is not the Heisenberg uncertainty of location and momentum; rather, location alone possesses a built-in uncertainty ...

  18. Prompt and Precise Prototyping

    Science.gov (United States)

    2003-01-01

    For Sanders Design International, Inc., of Wilton, New Hampshire, every passing second between the concept and realization of a product is essential to succeed in the rapid prototyping industry where amongst heavy competition, faster time-to-market means more business. To separate itself from its rivals, Sanders Design aligned with NASA's Marshall Space Flight Center to develop what it considers to be the most accurate rapid prototyping machine for fabrication of extremely precise tooling prototypes. The company's Rapid ToolMaker System has revolutionized production of high quality, small-to-medium sized prototype patterns and tooling molds with an exactness that surpasses that of computer numerically-controlled (CNC) machining devices. Created with funding and support from Marshall under a Small Business Innovation Research (SBIR) contract, the Rapid ToolMaker is a dual-use technology with applications in both commercial and military aerospace fields. The advanced technology provides cost savings in the design and manufacturing of automotive, electronic, and medical parts, as well as in other areas of consumer interest, such as jewelry and toys. For aerospace applications, the Rapid ToolMaker enables fabrication of high-quality turbine and compressor blades for jet engines on unmanned air vehicles, aircraft, and missiles.

  19. Precisely Tracking Childhood Death.

    Science.gov (United States)

    Farag, Tamer H; Koplan, Jeffrey P; Breiman, Robert F; Madhi, Shabir A; Heaton, Penny M; Mundel, Trevor; Ordi, Jaume; Bassat, Quique; Menendez, Clara; Dowell, Scott F

    2017-07-01

    Little is known about the specific causes of neonatal and under-five childhood death in high-mortality geographic regions due to a lack of primary data and dependence on inaccurate tools, such as verbal autopsy. To meet the ambitious new Sustainable Development Goal 3.2 to eliminate preventable child mortality in every country, better approaches are needed to precisely determine specific causes of death so that prevention and treatment interventions can be strengthened and focused. Minimally invasive tissue sampling (MITS) is a technique that uses needle-based postmortem sampling, followed by advanced histopathology and microbiology to definitely determine cause of death. The Bill & Melinda Gates Foundation is supporting a new surveillance system called the Child Health and Mortality Prevention Surveillance network, which will determine cause of death using MITS in combination with other information, and yield cause-specific population-based mortality rates, eventually in up to 12-15 sites in sub-Saharan Africa and south Asia. However, the Gates Foundation funding alone is not enough. We call on governments, other funders, and international stakeholders to expand the use of pathology-based cause of death determination to provide the information needed to end preventable childhood mortality.

  20. Testing methodologies

    Energy Technology Data Exchange (ETDEWEB)

    Bender, M.A.

    1990-01-01

    Several methodologies are available for screening human populations for exposure to ionizing radiation. Of these, aberration frequency determined in peripheral blood lymphocytes is the best developed. Individual exposures to large doses can easily be quantitated, and population exposures to occupational levels can be detected. However, determination of exposures to the very low doses anticipated from a low-level radioactive waste disposal site is more problematical. Aberrations occur spontaneously, without known cause. Exposure to radiation induces no new or novel types, but only increases their frequency. The limitations of chromosomal aberration dosimetry for detecting low level radiation exposures lie mainly in the statistical signal to noise'' problem, the distribution of aberrations among cells and among individuals, and the possible induction of aberrations by other environmental occupational or medical exposures. However, certain features of the human peripheral lymphocyte-chromosomal aberration system make it useful in screening for certain types of exposures. Future technical developments may make chromosomal aberration dosimetry more useful for low-level radiation exposures. Other methods, measuring gene mutations or even minute changes on the DNA level, while presently less will developed techniques, may eventually become even more practical and sensitive assays for human radiation exposure. 15 refs.

  1. Testing methodologies

    International Nuclear Information System (INIS)

    Bender, M.A.

    1990-01-01

    Several methodologies are available for screening human populations for exposure to ionizing radiation. Of these, aberration frequency determined in peripheral blood lymphocytes is the best developed. Individual exposures to large doses can easily be quantitated, and population exposures to occupational levels can be detected. However, determination of exposures to the very low doses anticipated from a low-level radioactive waste disposal site is more problematical. Aberrations occur spontaneously, without known cause. Exposure to radiation induces no new or novel types, but only increases their frequency. The limitations of chromosomal aberration dosimetry for detecting low level radiation exposures lie mainly in the statistical ''signal to noise'' problem, the distribution of aberrations among cells and among individuals, and the possible induction of aberrations by other environmental occupational or medical exposures. However, certain features of the human peripheral lymphocyte-chromosomal aberration system make it useful in screening for certain types of exposures. Future technical developments may make chromosomal aberration dosimetry more useful for low-level radiation exposures. Other methods, measuring gene mutations or even minute changes on the DNA level, while presently less will developed techniques, may eventually become even more practical and sensitive assays for human radiation exposure. 15 refs

  2. Sensitivity versus accuracy in multiclass problems using memetic Pareto evolutionary neural networks.

    Science.gov (United States)

    Fernández Caballero, Juan Carlos; Martínez, Francisco José; Hervás, César; Gutiérrez, Pedro Antonio

    2010-05-01

    This paper proposes a multiclassification algorithm using multilayer perceptron neural network models. It tries to boost two conflicting main objectives of multiclassifiers: a high correct classification rate level and a high classification rate for each class. This last objective is not usually optimized in classification, but is considered here given the need to obtain high precision in each class in real problems. To solve this machine learning problem, we use a Pareto-based multiobjective optimization methodology based on a memetic evolutionary algorithm. We consider a memetic Pareto evolutionary approach based on the NSGA2 evolutionary algorithm (MPENSGA2). Once the Pareto front is built, two strategies or automatic individual selection are used: the best model in accuracy and the best model in sensitivity (extremes in the Pareto front). These methodologies are applied to solve 17 classification benchmark problems obtained from the University of California at Irvine (UCI) repository and one complex real classification problem. The models obtained show high accuracy and a high classification rate for each class.

  3. Precise Truss Assembly Using Commodity Parts and Low Precision Welding

    Science.gov (United States)

    Komendera, Erik; Reishus, Dustin; Dorsey, John T.; Doggett, W. R.; Correll, Nikolaus

    2014-01-01

    Hardware and software design and system integration for an intelligent precision jigging robot (IPJR), which allows high precision assembly using commodity parts and low-precision bonding, is described. Preliminary 2D experiments that are motivated by the problem of assembling space telescope optical benches and very large manipulators on orbit using inexpensive, stock hardware and low-precision welding are also described. An IPJR is a robot that acts as the precise "jigging", holding parts of a local structure assembly site in place, while an external low precision assembly agent cuts and welds members. The prototype presented in this paper allows an assembly agent (for this prototype, a human using only low precision tools), to assemble a 2D truss made of wooden dowels to a precision on the order of millimeters over a span on the order of meters. The analysis of the assembly error and the results of building a square structure and a ring structure are discussed. Options for future work, to extend the IPJR paradigm to building in 3D structures at micron precision are also summarized.

  4. [Precision nutrition in the era of precision medicine].

    Science.gov (United States)

    Chen, P Z; Wang, H

    2016-12-06

    Precision medicine has been increasingly incorporated into clinical practice and is enabling a new era for disease prevention and treatment. As an important constituent of precision medicine, precision nutrition has also been drawing more attention during physical examinations. The main aim of precision nutrition is to provide safe and efficient intervention methods for disease treatment and management, through fully considering the genetics, lifestyle (dietary, exercise and lifestyle choices), metabolic status, gut microbiota and physiological status (nutrient level and disease status) of individuals. Three major components should be considered in precision nutrition, including individual criteria for sufficient nutritional status, biomarker monitoring or techniques for nutrient detection and the applicable therapeutic or intervention methods. It was suggested that, in clinical practice, many inherited and chronic metabolic diseases might be prevented or managed through precision nutritional intervention. For generally healthy populations, because lifestyles, dietary factors, genetic factors and environmental exposures vary among individuals, precision nutrition is warranted to improve their physical activity and reduce disease risks. In summary, research and practice is leading toward precision nutrition becoming an integral constituent of clinical nutrition and disease prevention in the era of precision medicine.

  5. Precision medicine in myasthenia graves: begin from the data precision

    Science.gov (United States)

    Hong, Yu; Xie, Yanchen; Hao, Hong-Jun; Sun, Ren-Cheng

    2016-01-01

    Myasthenia gravis (MG) is a prototypic autoimmune disease with overt clinical and immunological heterogeneity. The data of MG is far from individually precise now, partially due to the rarity and heterogeneity of this disease. In this review, we provide the basic insights of MG data precision, including onset age, presenting symptoms, generalization, thymus status, pathogenic autoantibodies, muscle involvement, severity and response to treatment based on references and our previous studies. Subgroups and quantitative traits of MG are discussed in the sense of data precision. The role of disease registries and scientific bases of precise analysis are also discussed to ensure better collection and analysis of MG data. PMID:27127759

  6. Accuracy of optical scanning methods of the Cerec®3D system in the process of making ceramic inlays

    Directory of Open Access Journals (Sweden)

    Trifković Branka

    2010-01-01

    Full Text Available Background/Aim. One of the results of many years of Cerec® 3D CAD/CAM system technological development is implementation of one intraoral and two extraoral optical scanning methods which, depending on the current indications, are applied in making fixed restorations. The aim of this study was to determine the degree of precision of optical scanning methods by the use of the Cerec®3D CAD/CAM system in the process of making ceramic inlays. Methods. The study was conducted in three experimental groups of inlays prepared using the procedure of three methods of scanning Cerec ®3D system. Ceramic inlays made by conventional methodology were the control group. The accuracy of optical scanning methods of the Cerec®3D system computer aided designcomputer aided manufacturing (CAD/CAM was indirectly examined by measuring a marginal gap size between inlays and demarcation preparation by scanning electron microscope (SEM. Results. The results of the study showed a difference in the accuracy of the existing methods of scanning dental CAD/CAM systems. The highest level of accuracy was achieved by the extraoral optical superficial scanning technique. The value of marginal gap size inlays made with the technique of extraoral optical superficial scanning was 32.97 ± 13.17 μ. Techniques of intraoral optical superficial and extraoral point laser scanning showed a lower level of accuracy (40.29 ± 21.46 μ for inlays of intraoral optical superficial scanning and 99.67 ± 37.25 μ for inlays of extraoral point laser scanning. Conclusion. Optical scanning methods in dental CAM/CAM technologies are precise methods of digitizing the spatial models; application of extraoral optical scanning methods provides the hightest precision.

  7. Glass ceramic ZERODUR enabling nanometer precision

    Science.gov (United States)

    Jedamzik, Ralf; Kunisch, Clemens; Nieder, Johannes; Westerhoff, Thomas

    2014-03-01

    The IC Lithography roadmap foresees manufacturing of devices with critical dimension of digit nanometer asking for nanometer positioning accuracy requiring sub nanometer position measurement accuracy. The glass ceramic ZERODUR® is a well-established material in critical components of microlithography wafer stepper and offered with an extremely low coefficient of thermal expansion (CTE), the tightest tolerance available on market. SCHOTT is continuously improving manufacturing processes and it's method to measure and characterize the CTE behavior of ZERODUR® to full fill the ever tighter CTE specification for wafer stepper components. In this paper we present the ZERODUR® Lithography Roadmap on the CTE metrology and tolerance. Additionally, simulation calculations based on a physical model are presented predicting the long term CTE behavior of ZERODUR® components to optimize dimensional stability of precision positioning devices. CTE data of several low thermal expansion materials are compared regarding their temperature dependence between - 50°C and + 100°C. ZERODUR® TAILORED 22°C is full filling the tight CTE tolerance of +/- 10 ppb / K within the broadest temperature interval compared to all other materials of this investigation. The data presented in this paper explicitly demonstrates the capability of ZERODUR® to enable the nanometer precision required for future generation of lithography equipment and processes.

  8. Soviet precision timekeeping research and technology

    Energy Technology Data Exchange (ETDEWEB)

    Vessot, R.F.C.; Allan, D.W.; Crampton, S.J.B.; Cutler, L.S.; Kern, R.H.; McCoubrey, A.O.; White, J.D.

    1991-08-01

    This report is the result of a study of Soviet progress in precision timekeeping research and timekeeping capability during the last two decades. The study was conducted by a panel of seven US scientists who have expertise in timekeeping, frequency control, time dissemination, and the direct applications of these disciplines to scientific investigation. The following topics are addressed in this report: generation of time by atomic clocks at the present level of their technology, new and emerging technologies related to atomic clocks, time and frequency transfer technology, statistical processes involving metrological applications of time and frequency, applications of precise time and frequency to scientific investigations, supporting timekeeping technology, and a comparison of Soviet research efforts with those of the United States and the West. The number of Soviet professionals working in this field is roughly 10 times that in the United States. The Soviet Union has facilities for large-scale production of frequency standards and has concentrated its efforts on developing and producing rubidium gas cell devices (relatively compact, low-cost frequency standards of modest accuracy and stability) and atomic hydrogen masers (relatively large, high-cost standards of modest accuracy and high stability). 203 refs., 45 figs., 9 tabs.

  9. Soviet precision timekeeping research and technology

    International Nuclear Information System (INIS)

    Vessot, R.F.C.; Allan, D.W.; Crampton, S.J.B.; Cutler, L.S.; Kern, R.H.; McCoubrey, A.O.; White, J.D.

    1991-08-01

    This report is the result of a study of Soviet progress in precision timekeeping research and timekeeping capability during the last two decades. The study was conducted by a panel of seven US scientists who have expertise in timekeeping, frequency control, time dissemination, and the direct applications of these disciplines to scientific investigation. The following topics are addressed in this report: generation of time by atomic clocks at the present level of their technology, new and emerging technologies related to atomic clocks, time and frequency transfer technology, statistical processes involving metrological applications of time and frequency, applications of precise time and frequency to scientific investigations, supporting timekeeping technology, and a comparison of Soviet research efforts with those of the United States and the West. The number of Soviet professionals working in this field is roughly 10 times that in the United States. The Soviet Union has facilities for large-scale production of frequency standards and has concentrated its efforts on developing and producing rubidium gas cell devices (relatively compact, low-cost frequency standards of modest accuracy and stability) and atomic hydrogen masers (relatively large, high-cost standards of modest accuracy and high stability). 203 refs., 45 figs., 9 tabs

  10. Complete-arch accuracy of intraoral scanners.

    Science.gov (United States)

    Treesh, Joshua C; Liacouras, Peter C; Taft, Robert M; Brooks, Daniel I; Raiciulescu, Sorana; Ellert, Daniel O; Grant, Gerald T; Ye, Ling

    2018-04-30

    Intraoral scanners have shown varied results in complete-arch applications. The purpose of this in vitro study was to evaluate the complete-arch accuracy of 4 intraoral scanners based on trueness and precision measurements compared with a known reference (trueness) and with each other (precision). Four intraoral scanners were evaluated: CEREC Bluecam, CEREC Omnicam, TRIOS Color, and Carestream CS 3500. A complete-arch reference cast was created and printed using a 3-dimensional dental cast printer with photopolymer resin. The reference cast was digitized using a laboratory-based white light 3-dimensional scanner. The printed reference cast was scanned 10 times with each intraoral scanner. The digital standard tessellation language (STL) files from each scanner were then registered to the reference file and compared with differences in trueness and precision using a 3-dimensional modeling software. Additionally, scanning time was recorded for each scan performed. The Wilcoxon signed rank, Kruskal-Wallis, and Dunn tests were used to detect differences for trueness, precision, and scanning time (α=.05). Carestream CS 3500 had the lowest overall trueness and precision compared with Bluecam and TRIOS Color. The fourth scanner, Omnicam, had intermediate trueness and precision. All of the scanners tended to underestimate the size of the reference file, with exception of the Carestream CS 3500, which was more variable. Based on visual inspection of the color rendering of signed differences, the greatest amount of error tended to be in the posterior aspects of the arch, with local errors exceeding 100 μm for all scans. The single capture scanner Carestream CS 3500 had the overall longest scan times and was significantly slower than the continuous capture scanners TRIOS Color and Omnicam. Significant differences in both trueness and precision were found among the scanners. Scan times of the continuous capture scanners were faster than the single capture scanners

  11. Robust precision alignment algorithm for micro tube laser forming

    NARCIS (Netherlands)

    Folkersma, Ger; Brouwer, Dannis Michel; Römer, Gerardus Richardus, Bernardus, Engelina; Herder, Justus Laurens

    2016-01-01

    Tube laser forming on a small diameter tube can be used as a high precision actuator to permanently align small (optical)components. Applications, such as the alignment of optical fibers to photonic integrated circuits, often require sub-micron alignment accuracy. Although the process causes

  12. Precision operation of the Nova laser for fusion experiments

    International Nuclear Information System (INIS)

    Caird, J.A.; Ehrlich, R.B.; Hermes, G.L.; Landen, O.L.; Laumann, C.W.; Lerche, R.A.; Miller, J.L.; Murray, J.E.; Nielsen, N.D.; Powell, H.T.; Rushford, M.C.; Saunders, R.L.; Thompson, C.E.; VanArsdall, P.J.; Vann, C.S.; Weiland, T.L.

    1994-01-01

    The operation of a Neodymium glass laser of a special design for fusion experiments is improved by a better pulse synchronization, the gain stabilization, and the laser diagnostics. We used sensor upgrading and antifriction coating of focusing lenses. The pointing accuracy of the Nova laser meets now our goal for precision operation. (AIP) copyright 1994 American Institute of Physics

  13. Feasibility of the Precise Energy Calibration for Fast Neutron Spectrometers

    Science.gov (United States)

    Gaganov, V. V.; Usenko, P. L.; Kryzhanovskaja, M. A.

    2017-12-01

    Computational studies aimed at improving the accuracy of measurements performed using neutron generators with a tritium target were performed. A measurement design yielding an extremely narrow peak in the energy spectrum of DT neutrons was found. The presence of such a peak establishes the conditions for precise energy calibration of fast-neutron spectrometers.

  14. Integrated Quality Control of Precision Assemblies using Computed Tomography

    DEFF Research Database (Denmark)

    Stolfi, Alessandro

    coor-dinate measuring machines (CMMs) when working with complex and fragile parts. This Ph.D. project at DTU Mechanical Engineering concerns the applicability of CT for quality control of precision assem-blies. Investigations to quantify the accuracy of CT measurements, reference artefacts to correct...

  15. Diagnostic accuracy of CT angiography in acute gastrointestinal bleeding

    International Nuclear Information System (INIS)

    Chua, A. E.; Ridley, L. J.

    2008-01-01

    Full text: The aim of the study was to carry out a systematic review determining the accuracy of CT angiography in the diagnosis of acute gastrointestinal bleeding. A search of published work in Medline and manual searching of reference lists of articles was conducted. Studies were included if they compared CT angiography to a reference standard of upper gastrointestinal endoscopy, colonoscopy, angiography or surgery in the diagnosis of acute gastrointestinal bleeding. Eight published studies evaluating 129 patients were included. Data were used to form 2 x2 tables. Computed tomography angiography showed pooled sensitivity of 86% (95% confidence interval 78-92%) and specificity of 95% (95% confidence interval 76-100%), without showing significant heterogeneity (x 2 = 3.5, P=0.6) and (x 2 - 5.4, P = 0.6), respectively. Summary receiver operating characteristic analysis showed an area under the curve of 0.93. Computed tomography angiography is accurate in the diagnosis of acute gastrointestinal bleeding and can show the precise location and aetiology of bleeding, thereby directing further management. Strong recommendations for use of CT cannot be made from this review because of the methodological limitations and further large prospective studies are needed to define the role of CT in acute gastrointestinal bleeding.

  16. Evaluating the accuracy of vehicle tracking data obtained from Unmanned Aerial Vehicles

    Directory of Open Access Journals (Sweden)

    Giuseppe Guido

    2016-10-01

    Full Text Available This paper presents a methodology for tracking moving vehicles that integrates Unmanned Aerial Vehicles with video processing techniques. The authors investigated the usefulness of Unmanned Aerial Vehicles to capture reliable individual vehicle data by using GPS technology as a benchmark. A video processing algorithm for vehicles trajectory acquisition is introduced. The algorithm is based on OpenCV libraries. In order to assess the accuracy of the proposed video processing algorithm an instrumented vehicle was equipped with a high precision GPS. The video capture experiments were performed in two case studies. From the field, about 24,000 positioning data were acquired for the analysis. The results of these experiments highlight the versatility of the Unmanned Aerial Vehicles technology combined with video processing technique in monitoring real traffic data.

  17. Improving shuffler assay accuracy

    International Nuclear Information System (INIS)

    Rinard, P.M.

    1995-01-01

    Drums of uranium waste should be disposed of in an economical and environmentally sound manner. The most accurate possible assays of the uranium masses in the drums are required for proper disposal. The accuracies of assays from a shuffler are affected by the type of matrix material in the drums. Non-hydrogenous matrices have little effect on neutron transport and accuracies are very good. If self-shielding is known to be a minor problem, good accuracies are also obtained with hydrogenous matrices when a polyethylene sleeve is placed around the drums. But for those cases where self-shielding may be a problem, matrices are hydrogenous, and uranium distributions are non-uniform throughout the drums, the accuracies are degraded. They can be greatly improved by determining the distributions of the uranium and then applying correction factors based on the distributions. This paper describes a technique for determining uranium distributions by using the neutron count rates in detector banks around the waste drum and solving a set of overdetermined linear equations. Other approaches were studied to determine the distributions and are described briefly. Implementation of this correction is anticipated on an existing shuffler next year

  18. Precision Instrumentation Amplifiers and Read-Out Integrated Circuits

    CERN Document Server

    Wu, Rong; Makinwa, Kofi A A

    2013-01-01

    This book presents innovative solutions in the design of precision instrumentation amplifier and read-out ICs, which can be used to boost millivolt-level signals transmitted by modern sensors, to levels compatible with the input ranges of typical Analog-to-Digital Converters (ADCs).  The discussion includes the theory, design and realization of interface electronics for bridge transducers and thermocouples. It describes the use of power efficient techniques to mitigate low frequency errors, resulting in interface electronics with high accuracy, low noise and low drift. Since this book is mainly about techniques for eliminating low frequency errors, it describes the nature of these errors and the associated dynamic offset cancellation techniques used to mitigate them.  Surveys comprehensively offset cancellation and accuracy improvement techniques applied in precision amplifier designs; Presents techniques in precision circuit design to mitigate low frequency errors in millivolt-level signals transmitted by ...

  19. High precision neutron polarization for PERC

    International Nuclear Information System (INIS)

    Klauser, C.

    2013-01-01

    The decay of the free neutron into a proton, an electron and an anti-electron neutrino offers a simple system to study the semi-leptonic weak decay. High precision measurements of angular correlation coefficients of this decay provide the opportunity to test the standard model on the low energy frontier. The Proton Electron Radiation Channel PERC is part of a new generation of expriments pushing the accuracy of such an angular correlation coefficient measurement towards 10 -4 . Past experiments have been limited to an accuracy of 10 -3 with uncertainties on the neutron polarization as one of the leading systematic errors. This thesis focuses on the development of a stable, highly precise neutron polarization for a large, divergent cold neutron beam. A diagnostic tool that provides polarization higher than 99.99 % and analyzes with an accuracy of 10 -4 , the Opaque Test Bench, is presented and validated. It consists of two highly opaque polarized helium cells. The Opaque Test Bench reveals depolarizing effects in polarizing supermirrors commonly used for polarization in neutron decay experiments. These effects are investigated in detail. They are due to imperfect lateral magnetization in supermirror layers and can be minimized by significantly increased magnetizing fields and low incidence angle and supermirror factor m. A subsequent test in the crossed (X-SM) geometry demonstrated polarizations up to 99.97% from supermirrors only, improving neutron polarization with supermirrors by an order of magnitude. The thesis also discusses other neutron optical components of the PERC beamline: Monte-Carlo simulations of the beamline under consideration of the primary guide are carried out. In addition, calculation shows that PERC would statistically profit from an installation at the European Spallation source. Furthermore, beamline components were tested. A radio-frequency spin flipper was confirmed to work with an efficiency higher than 0.9999. (author) [de

  20. 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.

  1. Quantitative code accuracy evaluation of ISP33

    Energy Technology Data Exchange (ETDEWEB)

    Kalli, H.; Miwrrin, A. [Lappeenranta Univ. of Technology (Finland); Purhonen, H. [VTT Energy, Lappeenranta (Finland)] [and others

    1995-09-01

    Aiming at quantifying code accuracy, a methodology based on the Fast Fourier Transform has been developed at the University of Pisa, Italy. The paper deals with a short presentation of the methodology and its application to pre-test and post-test calculations submitted to the International Standard Problem ISP33. This was a double-blind natural circulation exercise with a stepwise reduced primary coolant inventory, performed in PACTEL facility in Finland. PACTEL is a 1/305 volumetrically scaled, full-height simulator of the Russian type VVER-440 pressurized water reactor, with horizontal steam generators and loop seals in both cold and hot legs. Fifteen foreign organizations participated in ISP33, with 21 blind calculations and 20 post-test calculations, altogether 10 different thermal hydraulic codes and code versions were used. The results of the application of the methodology to nine selected measured quantities are summarized.

  2. Accuracy Assessment of Different Digital Surface Models

    Directory of Open Access Journals (Sweden)

    Ugur Alganci

    2018-03-01

    Full Text Available Digital elevation models (DEMs, which can occur in the form of digital surface models (DSMs or digital terrain models (DTMs, are widely used as important geospatial information sources for various remote sensing applications, including the precise orthorectification of high-resolution satellite images, 3D spatial analyses, multi-criteria decision support systems, and deformation monitoring. The accuracy of DEMs has direct impacts on specific calculations and process chains; therefore, it is important to select the most appropriate DEM by considering the aim, accuracy requirement, and scale of each study. In this research, DSMs obtained from a variety of satellite sensors were compared to analyze their accuracy and performance. For this purpose, freely available Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER 30 m, Shuttle Radar Topography Mission (SRTM 30 m, and Advanced Land Observing Satellite (ALOS 30 m resolution DSM data were obtained. Additionally, 3 m and 1 m resolution DSMs were produced from tri-stereo images from the SPOT 6 and Pleiades high-resolution (PHR 1A satellites, respectively. Elevation reference data provided by the General Command of Mapping, the national mapping agency of Turkey—produced from 30 cm spatial resolution stereo aerial photos, with a 5 m grid spacing and ±3 m or better overall vertical accuracy at the 90% confidence interval (CI—were used to perform accuracy assessments. Gross errors and water surfaces were removed from the reference DSM. The relative accuracies of the different DSMs were tested using a different number of checkpoints determined by different methods. In the first method, 25 checkpoints were selected from bare lands to evaluate the accuracies of the DSMs on terrain surfaces. In the second method, 1000 randomly selected checkpoints were used to evaluate the methods’ accuracies for the whole study area. In addition to the control point approach, vertical cross

  3. Precision of different quantitative ultrasound densitometers

    International Nuclear Information System (INIS)

    Pocock, N.A.; Harris, N.D.; Griffiths, M.R.

    1998-01-01

    Full text: Quantitative ultrasound (QUS) of the calcaneus, which measures Speed of Sound (SOS) and Broadband ultrasound attenuation (BUA), is predictive of the risk of osteoporotic fracture. However, the utility of QUS for predicting fracture risk or for monitoring treatment efficacy depends on its precision and reliability. Published results and manufacturers data vary significantly due to differences in statistical methodology. We have assessed the precision of the current model of the Lunar Achilles and the McCue Cuba QUS densitometers; the most commonly used QUS machines in Australia. Twenty seven subjects had duplicate QUS measurements performed on the same day on both machines. These data were used to calculate the within pair standard deviation (SD) the co-efficient of variation, CV and the standardised co efficient of variation (sCV) which is corrected for the dynamic range. In addition, the co-efficient of reliability (R) was calculated as an index of reliability which is independent of the population mean value, or the dynamic range of the measurements. R ranges between 0 (for no reliability) to 1(for a perfect reliability). The results indicate that the precision of QUS is dependent on the dynamic range and the instrument. Furthermore, they suggest that while QUS is a useful predictor of fracture risk, at present it has limited clinical value in monitoring short term age-related bone loss of 1-2% per year

  4. Surface characterization protocol for precision aspheric optics

    Science.gov (United States)

    Sarepaka, RamaGopal V.; Sakthibalan, Siva; Doodala, Somaiah; Panwar, Rakesh S.; Kotaria, Rajendra

    2017-10-01

    In Advanced Optical Instrumentation, Aspherics provide an effective performance alternative. The aspheric fabrication and surface metrology, followed by aspheric design are complementary iterative processes for Precision Aspheric development. As in fabrication, a holistic approach of aspheric surface characterization is adopted to evaluate actual surface error and to aim at the deliverance of aspheric optics with desired surface quality. Precision optical surfaces are characterized by profilometry or by interferometry. Aspheric profiles are characterized by contact profilometers, through linear surface scans to analyze their Form, Figure and Finish errors. One must ensure that, the surface characterization procedure does not add to the resident profile errors (generated during the aspheric surface fabrication). This presentation examines the errors introduced post-surface generation and during profilometry of aspheric profiles. This effort is to identify sources of errors and is to optimize the metrology process. The sources of error during profilometry may be due to: profilometer settings, work-piece placement on the profilometer stage, selection of zenith/nadir points of aspheric profiles, metrology protocols, clear aperture - diameter analysis, computational limitations of the profiler and the software issues etc. At OPTICA, a PGI 1200 FTS contact profilometer (Taylor-Hobson make) is used for this study. Precision Optics of various profiles are studied, with due attention to possible sources of errors during characterization, with multi-directional scan approach for uniformity and repeatability of error estimation. This study provides an insight of aspheric surface characterization and helps in optimal aspheric surface production methodology.

  5. Case Study: Meeting the Demand for Skilled Precision Engineers

    Science.gov (United States)

    Sansom, Chris; Shore, Paul

    2008-01-01

    Purpose: This paper aims to demonstrate how science and engineering graduates can be recruited and trained to Masters level in precision engineering as an aid to reducing the skills shortage of mechanical engineers in UK industry. Design/methodology/approach: The paper describes a partnership between three UK academic institutions and industry,…

  6. Precise GNSS Positioning Using Smart Devices

    Directory of Open Access Journals (Sweden)

    Eugenio Realini

    2017-10-01

    Full Text Available The recent access to GNSS (Global Navigation Satellite System phase observations on smart devices, enabled by Google through its Android operating system, opens the possibility to apply precise positioning techniques using off-the-shelf, mass-market devices. The target of this work is to evaluate whether this is feasible, and which positioning accuracy can be achieved by relative positioning of the smart device with respect to a base station. Positioning of a Google/HTC Nexus 9 tablet was performed by means of batch least-squares adjustment of L1 phase double-differenced observations, using the open source goGPS software, over baselines ranging from approximately 10 m to 8 km, with respect to both physical (geodetic or low-cost and virtual base stations. The same positioning procedure was applied also to a co-located u-blox low-cost receiver, to compare the performance between the receiver and antenna embedded in the Nexus 9 and a standard low-cost single-frequency receiver with external patch antenna. The results demonstrate that with a smart device providing raw GNSS phase observations, like the Nexus 9, it is possible to reach decimeter-level accuracy through rapid-static surveys, without phase ambiguity resolution. It is expected that sub-centimeter accuracy could be achieved, as demonstrated for the u-blox case, if integer phase ambiguities were correctly resolved.

  7. Precision segmented reflectors for space applications

    Science.gov (United States)

    Lehman, David H.; Pawlik, Eugene V.; Meinel, Aden B.; Fichter, W. B.

    1990-08-01

    A project to develop precision segmented reflectors (PSRs) which operate at submillimeter wavelengths is described. The development of a light efficient means for the construction of large-aperture segmented reflecting space-based telescopes is the primary aim of the project. The 20-m Large Deployable Reflector (LDR) telescope is being developed for a survey mission, and it will make use of the reflector panels and materials, structures, and figure control being elaborated for the PSR. The surface accuracy of a 0.9-m PSR panel is shown to be 1.74-micron RMS, the goal of 100-micron RMS positioning accuracy has been achieved for a 4-m erectable structure. A voice-coil actuator for the figure control system architecture demonstrated 1-micron panel control accuracy in a 3-axis evaluation. The PSR technology is demonstrated to be of value for several NASA projects involving optical communications and interferometers as well as missions which make use of large-diameter segmented reflectors.

  8. Precise GNSS Positioning Using Smart Devices.

    Science.gov (United States)

    Realini, Eugenio; Caldera, Stefano; Pertusini, Lisa; Sampietro, Daniele

    2017-10-24

    The recent access to GNSS (Global Navigation Satellite System) phase observations on smart devices, enabled by Google through its Android operating system, opens the possibility to apply precise positioning techniques using off-the-shelf, mass-market devices. The target of this work is to evaluate whether this is feasible, and which positioning accuracy can be achieved by relative positioning of the smart device with respect to a base station. Positioning of a Google/HTC Nexus 9 tablet was performed by means of batch least-squares adjustment of L1 phase double-differenced observations, using the open source goGPS software, over baselines ranging from approximately 10 m to 8 km, with respect to both physical (geodetic or low-cost) and virtual base stations. The same positioning procedure was applied also to a co-located u-blox low-cost receiver, to compare the performance between the receiver and antenna embedded in the Nexus 9 and a standard low-cost single-frequency receiver with external patch antenna. The results demonstrate that with a smart device providing raw GNSS phase observations, like the Nexus 9, it is possible to reach decimeter-level accuracy through rapid-static surveys, without phase ambiguity resolution. It is expected that sub-centimeter accuracy could be achieved, as demonstrated for the u-blox case, if integer phase ambiguities were correctly resolved.

  9. Matter power spectrum and the challenge of percent accuracy

    OpenAIRE

    Schneider, Aurel; Teyssier, Romain; Potter, Doug; Stadel, Joachim; Onions, Julian; Reed, Darren S.; Smith, Robert E.; Springel, Volker; Pearce, Frazer R.; Scoccimarro, Roman

    2015-01-01

    Future galaxy surveys require one percent precision in the theoretical knowledge of the power spectrum over a large range including very nonlinear scales. While this level of accuracy is easily obtained in the linear regime with perturbation theory, it represents a serious challenge for small scales where numerical simulations are required. In this paper we quantify the precision of present-day $N$-body methods, identifying main potential error sources from the set-up of initial conditions to...

  10. Advancing Precision Nuclear Medicine and Molecular Imaging for Lymphoma.

    Science.gov (United States)

    Wright, Chadwick L; Maly, Joseph J; Zhang, Jun; Knopp, Michael V

    2017-01-01

    PET with fluorodeoxyglucose F 18 ( 18 F FDG-PET) is a meaningful biomarker for the detection, targeted biopsy, and treatment of lymphoma. This article reviews the evolution of 18 F FDG-PET as a putative biomarker for lymphoma and addresses the current capabilities, challenges, and opportunities to enable precision medicine practices for lymphoma. Precision nuclear medicine is driven by new imaging technologies and methodologies to more accurately detect malignant disease. Although quantitative assessment of response is limited, such technologies will enable a more precise metabolic mapping with much higher definition image detail and thus may make it a robust and valid quantitative response assessment methodology. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Accuracy of recumbent height measurement.

    Science.gov (United States)

    Gray, D S; Crider, J B; Kelley, C; Dickinson, L C

    1985-01-01

    Since many patients requiring specialized nutritional support are bedridden, measurement of height for purposes of nutritional assessment or prescription must often be done with the patient in bed. This study examined the accuracy of measuring body height in bed in the supine position. Two measurements were performed on 108 ambulatory inpatients: (1) standing height using a standard height-weight scale, and (2) bed height using a flexible tape. Patients were divided into four groups based on which of two researchers performed each of the two measurements. Each patient was also weighed and self-reported height, weight, sex, and age were recorded. Bed height was significantly longer than standing height by 3.68 cm, but the two measurements were equally precise. It was believed, however, that this 2% difference was probably not clinically significant in most circumstances. Bed height correlated highly with standing height (r = 0.95), and the regression equation was standing height = 13.82 +/- 0.09 bed height. Patients overestimated their heights. Heights recorded by nurses were more accurate when patients were measured than when asked about their heights, but the patients were more often asked than measured.

  12. MEASUREMENT AND PRECISION, EXPERIMENTAL VERSION.

    Science.gov (United States)

    Harvard Univ., Cambridge, MA. Harvard Project Physics.

    THIS DOCUMENT IS AN EXPERIMENTAL VERSION OF A PROGRAMED TEXT ON MEASUREMENT AND PRECISION. PART I CONTAINS 24 FRAMES DEALING WITH PRECISION AND SIGNIFICANT FIGURES ENCOUNTERED IN VARIOUS MATHEMATICAL COMPUTATIONS AND MEASUREMENTS. PART II BEGINS WITH A BRIEF SECTION ON EXPERIMENTAL DATA, COVERING SUCH POINTS AS (1) ESTABLISHING THE ZERO POINT, (2)…

  13. Precision medicine for nurses: 101.

    Science.gov (United States)

    Lemoine, Colleen

    2014-05-01

    To introduce the key concepts and terms associated with precision medicine and support understanding of future developments in the field by providing an overview and history of precision medicine, related ethical considerations, and nursing implications. Current nursing, medical and basic science literature. Rapid progress in understanding the oncogenic drivers associated with cancer is leading to a shift toward precision medicine, where treatment is based on targeting specific genetic and epigenetic alterations associated with a particular cancer. Nurses will need to embrace the paradigm shift to precision medicine, expend the effort necessary to learn the essential terminology, concepts and principles, and work collaboratively with physician colleagues to best position our patients to maximize the potential that precision medicine can offer. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Geoid undulation accuracy

    Science.gov (United States)

    Rapp, Richard H.

    1993-01-01

    The determination of the geoid and equipotential surface of the Earth's gravity field, has long been of interest to geodesists and oceanographers. The geoid provides a surface to which the actual ocean surface can be compared with the differences implying information on the circulation patterns of the oceans. For use in oceanographic applications the geoid is ideally needed to a high accuracy and to a high resolution. There are applications that require geoid undulation information to an accuracy of +/- 10 cm with a resolution of 50 km. We are far from this goal today but substantial improvement in geoid determination has been made. In 1979 the cumulative geoid undulation error to spherical harmonic degree 20 was +/- 1.4 m for the GEM10 potential coefficient model. Today the corresponding value has been reduced to +/- 25 cm for GEM-T3 or +/- 11 cm for the OSU91A model. Similar improvements are noted by harmonic degree (wave-length) and in resolution. Potential coefficient models now exist to degree 360 based on a combination of data types. This paper discusses the accuracy changes that have taken place in the past 12 years in the determination of geoid undulations.

  15. French Meteor Network for High Precision Orbits of Meteoroids

    Science.gov (United States)

    Atreya, P.; Vaubaillon, J.; Colas, F.; Bouley, S.; Gaillard, B.; Sauli, I.; Kwon, M. K.

    2011-01-01

    There is a lack of precise meteoroids orbit from video observations as most of the meteor stations use off-the-shelf CCD cameras. Few meteoroids orbit with precise semi-major axis are available using film photographic method. Precise orbits are necessary to compute the dust flux in the Earth s vicinity, and to estimate the ejection time of the meteoroids accurately by comparing them with the theoretical evolution model. We investigate the use of large CCD sensors to observe multi-station meteors and to compute precise orbit of these meteoroids. An ideal spatial and temporal resolution to get an accuracy to those similar of photographic plates are discussed. Various problems faced due to the use of large CCD, such as increasing the spatial and the temporal resolution at the same time and computational problems in finding the meteor position are illustrated.

  16. High-precision thermal and electrical characterization of thermoelectric modules

    Science.gov (United States)

    Kolodner, Paul

    2014-05-01

    This paper describes an apparatus for performing high-precision electrical and thermal characterization of thermoelectric modules (TEMs). The apparatus is calibrated for operation between 20 °C and 80 °C and is normally used for measurements of heat currents in the range 0-10 W. Precision thermometry based on miniature thermistor probes enables an absolute temperature accuracy of better than 0.010 °C. The use of vacuum isolation, thermal guarding, and radiation shielding, augmented by a careful accounting of stray heat leaks and uncertainties, allows the heat current through the TEM under test to be determined with a precision of a few mW. The fractional precision of all measured parameters is approximately 0.1%.

  17. Testing of parameters of proposed robotic wrist based on the precision modules

    Directory of Open Access Journals (Sweden)

    Jan Semjon

    2016-10-01

    Full Text Available The use of precision actuators in robotic arm comes from the need to ensure the resulting accuracy of the robot at the maximum speed of movement. The replacement of actuators by means of electrical module allows the use of carrier body of the module for gripping flanges or other modules. Development of new modules is based on the requirement of providing a complete solution for the customer’s needs. After the development of new modules, the producer checks the parameters, receives feedback, and uses the authentication options in the independent workplaces, which can provide impartial results. Based on this data, manufacturers can optimize their solutions and deliver the products to market, complying with not only their vision but mainly the needs of customers. This article describes how to verify the characteristics of the modules used in the construction of robotic wrist. It primarily focuses on verification of the accuracy of results and repeatability of position of the wrist on output flange end module. In addition, it presents the design of the testing stand and selection methodologies of measurement. The declared values are compared with the values measured during verification.

  18. Advanced bioanalytics for precision medicine.

    Science.gov (United States)

    Roda, Aldo; Michelini, Elisa; Caliceti, Cristiana; Guardigli, Massimo; Mirasoli, Mara; Simoni, Patrizia

    2018-01-01

    Precision medicine is a new paradigm that combines diagnostic, imaging, and analytical tools to produce accurate diagnoses and therapeutic interventions tailored to the individual patient. This approach stands in contrast to the traditional "one size fits all" concept, according to which researchers develop disease treatments and preventions for an "average" patient without considering individual differences. The "one size fits all" concept has led to many ineffective or inappropriate treatments, especially for pathologies such as Alzheimer's disease and cancer. Now, precision medicine is receiving massive funding in many countries, thanks to its social and economic potential in terms of improved disease prevention, diagnosis, and therapy. Bioanalytical chemistry is critical to precision medicine. This is because identifying an appropriate tailored therapy requires researchers to collect and analyze information on each patient's specific molecular biomarkers (e.g., proteins, nucleic acids, and metabolites). In other words, precision diagnostics is not possible without precise bioanalytical chemistry. This Trend article highlights some of the most recent advances, including massive analysis of multilayer omics, and new imaging technique applications suitable for implementing precision medicine. Graphical abstract Precision medicine combines bioanalytical chemistry, molecular diagnostics, and imaging tools for performing accurate diagnoses and selecting optimal therapies for each patient.

  19. High Precision Sunphotometer using Wide Dynamic Range (WDR) Camera Tracking

    Science.gov (United States)

    Liss, J.; Dunagan, S. E.; Johnson, R. R.; Chang, C. S.; LeBlanc, S. E.; Shinozuka, Y.; Redemann, J.; Flynn, C. J.; Segal-Rosenhaimer, M.; Pistone, K.; Kacenelenbogen, M. S.; Fahey, L.

    2016-12-01

    High Precision Sunphotometer using Wide Dynamic Range (WDR) Camera TrackingThe NASA Ames Sun-photometer-Satellite Group, DOE, PNNL Atmospheric Sciences and Global Change Division, and NASA Goddard's AERONET (AErosol RObotic NETwork) team recently collaborated on the development of a new airborne sunphotometry instrument that provides information on gases and aerosols extending far beyond what can be derived from discrete-channel direct-beam measurements, while preserving or enhancing many of the desirable AATS features (e.g., compactness, versatility, automation, reliability). The enhanced instrument combines the sun-tracking ability of the current 14-Channel NASA Ames AATS-14 with the sky-scanning ability of the ground-based AERONET Sun/sky photometers, while extending both AATS-14 and AERONET capabilities by providing full spectral information from the UV (350 nm) to the SWIR (1,700 nm). Strengths of this measurement approach include many more wavelengths (isolated from gas absorption features) that may be used to characterize aerosols and detailed (oversampled) measurements of the absorption features of specific gas constituents. The Sky Scanning Sun Tracking Airborne Radiometer (3STAR) replicates the radiometer functionality of the AATS-14 instrument but incorporates modern COTS technologies for all instruments subsystems. A 19-channel radiometer bundle design is borrowed from a commercial water column radiance instrument manufactured by Biospherical Instruments of San Diego California (ref, Morrow and Hooker)) and developed using NASA funds under the Small Business Innovative Research (SBIR) program. The 3STAR design also incorporates the latest in robotic motor technology embodied in Rotary actuators from Oriental motor Corp. having better than 15 arc seconds of positioning accuracy. Control system was designed, tested and simulated using a Hybrid-Dynamical modeling methodology. The design also replaces the classic quadrant detector tracking sensor with a

  20. Comparison of the precision of three commonly used GPS models

    Directory of Open Access Journals (Sweden)

    E Chavoshi

    2016-04-01

    Full Text Available Introduction: Development of science in various fields has caused change in the methods to determine geographical location. Precision farming involves new technology that provides the opportunity for farmers to change in factors such as nutrients, soil moisture available to plants, soil physical and chemical characteristics and other factors with the spatial resolution of less than a centimeter to several meters to monitor and evaluate. GPS receivers based on precision farming operations specified accuracies are used in the following areas: 1 monitoring of crop and soil sampling (less than one meter accuracy 2 use of fertilizer, pesticide and seed work (less than half a meter accuracy 3 Transplantation and row cultivation (precision of less than 4 cm (Perez et al., 2011. In one application of GPS in agriculture, route guidance precision farming tractors in the fields was designed to reduce the transmission error that deviate from the path specified in the range of 50 to 300 mm driver informed and improved way to display (Perez et al., 2011. In another study, the system automatically guidance, based on RTK-GPS technology, precision tillage operations was used between and within the rows very close to the drip irrigation pipe and without damage to their crops at a distance of 50 mm (Abidine et al., 2004. In another study, to compare the accuracy and precision of the receivers, 5 different models of Trimble Mark GPS devices from 15 stations were mapped, the results indicated that minimum error was related to Geo XT model with an accuracy of 91 cm and maximum error was related to Pharos model with an accuracy of 5.62 m (Kindra et al., 2006. Due to the increasing use of GPS receivers in agriculture as well as the lack of trust on the real accuracy and precision of receivers, this study aimed to compare the positioning accuracy and precision of three commonly used GPS receivers models used to specify receivers with the lowest error for precision

  1. Precision Oncology: Between Vaguely Right and Precisely Wrong.

    Science.gov (United States)

    Brock, Amy; Huang, Sui

    2017-12-01

    Precision Oncology seeks to identify and target the mutation that drives a tumor. Despite its straightforward rationale, concerns about its effectiveness are mounting. What is the biological explanation for the "imprecision?" First, Precision Oncology relies on indiscriminate sequencing of genomes in biopsies that barely represent the heterogeneous mix of tumor cells. Second, findings that defy the orthodoxy of oncogenic "driver mutations" are now accumulating: the ubiquitous presence of oncogenic mutations in silent premalignancies or the dynamic switching without mutations between various cell phenotypes that promote progression. Most troublesome is the observation that cancer cells that survive treatment still will have suffered cytotoxic stress and thereby enter a stem cell-like state, the seeds for recurrence. The benefit of "precision targeting" of mutations is inherently limited by this counterproductive effect. These findings confirm that there is no precise linear causal relationship between tumor genotype and phenotype, a reminder of logician Carveth Read's caution that being vaguely right may be preferable to being precisely wrong. An open-minded embrace of the latest inconvenient findings indicating nongenetic and "imprecise" phenotype dynamics of tumors as summarized in this review will be paramount if Precision Oncology is ultimately to lead to clinical benefits. Cancer Res; 77(23); 6473-9. ©2017 AACR . ©2017 American Association for Cancer Research.

  2. Numerical precision control and GRACE

    International Nuclear Information System (INIS)

    Fujimoto, J.; Hamaguchi, N.; Ishikawa, T.; Kaneko, T.; Morita, H.; Perret-Gallix, D.; Tokura, A.; Shimizu, Y.

    2006-01-01

    The control of the numerical precision of large-scale computations like those generated by the GRACE system for automatic Feynman diagram calculations has become an intrinsic part of those packages. Recently, Hitachi Ltd. has developed in FORTRAN a new library HMLIB for quadruple and octuple precision arithmetic where the number of lost-bits is made available. This library has been tested with success on the 1-loop radiative correction to e + e - ->e + e - τ + τ - . It is shown that the approach followed by HMLIB provides an efficient way to track down the source of numerical significance losses and to deliver high-precision results yet minimizing computing time

  3. Evaluation of the Precision of Satellite-Derived Sea Surface Temperature Fields

    Science.gov (United States)

    Wu, F.; Cornillon, P. C.; Guan, L.

    2016-02-01

    A great deal of attention has been focused on the temporal accuracy of satellite-derived sea surface temperature (SST) fields with little attention being given to their spatial precision. Specifically, the primary measure of the quality of SST fields has been the bias and variance of selected values minus co-located (in space and time) in situ values. Contributing values, determined by the location of the in situ values and the necessity that the satellite-derived values be cloud free, are generally widely separated in space and time hence provide little information related to the pixel-to-pixel uncertainty in the retrievals. But the main contribution to the uncertainty in satellite-derived SST retrievals relates to atmospheric contamination and because the spatial scales of atmospheric features are, in general, large compared with the pixel separation of modern infra-red sensors, the pixel-to-pixel uncertainty is often smaller than the accuracy determined from in situ match-ups. This makes selection of satellite-derived datasets for the study of submesoscale processes, for which the spatial structure of the upper ocean is significant, problematic. In this presentation we present a methodology to characterize the spatial precision of satellite-derived SST fields. The method is based on an examination of the high wavenumber tail of the 2-D spectrum of SST fields in the Sargasso Sea, a low energy region of the ocean close to the track of the MV Oleander, a container ship making weekly roundtrips between New York and Bermuda, with engine intake temperatures sampled every 75 m along track. Important spectral characteristics are the point at which the satellite-derived spectra separate from the Oleander spectra and the spectral slope following separation. In this presentation a number of high resolution 375 m to 10 km SST datasets are evaluated based on this approach.

  4. Accuracy of Digital vs. Conventional Implant Impressions

    Science.gov (United States)

    Lee, Sang J.; Betensky, Rebecca A.; Gianneschi, Grace E.; Gallucci, German O.

    2015-01-01

    The accuracy of digital impressions greatly influences the clinical viability in implant restorations. The aim of this study is to compare the accuracy of gypsum models acquired from the conventional implant impression to digitally milled models created from direct digitalization by three-dimensional analysis. Thirty gypsum and 30 digitally milled models impressed directly from a reference model were prepared. The models were scanned by a laboratory scanner and 30 STL datasets from each group were imported to an inspection software. The datasets were aligned to the reference dataset by a repeated best fit algorithm and 10 specified contact locations of interest were measured in mean volumetric deviations. The areas were pooled by cusps, fossae, interproximal contacts, horizontal and vertical axes of implant position and angulation. The pooled areas were statistically analysed by comparing each group to the reference model to investigate the mean volumetric deviations accounting for accuracy and standard deviations for precision. Milled models from digital impressions had comparable accuracy to gypsum models from conventional impressions. However, differences in fossae and vertical displacement of the implant position from the gypsum and digitally milled models compared to the reference model, exhibited statistical significance (p<0.001, p=0.020 respectively). PMID:24720423

  5. Methodology of characterization of radioactive graphite

    International Nuclear Information System (INIS)

    Pina, G.; Rodriguez, M.; Lara, E.; Magro, E.; Gascon, J. L.; Leganes, J. L.

    2014-01-01

    Since the dismantling of Vandellos I, ENRESA has promoted the precise knowledge of the inventory of irradiated graphite (graphite-i) through establishing methodologies for radiological characterization of the vector of radionuclides of interest and their correlations as the primary means of characterization strategy to establish the safer management of this material in its life cycle. (Author)

  6. Image Positioning Accuracy Analysis for Super Low Altitude Remote Sensing Satellites

    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.

  7. Sfermion Precision Measurements at a Linear Collider

    CERN Document Server

    Freitas, A.; Ananthanarayan, B.; Bartl, A.; Blair, G.A.; Blochinger, C.; Boos, E.; Brandenburg, A.; Datta, A.; Djouadi, A.; Fraas, H.; Guasch, J.; Hesselbach, S.; Hidaka, K.; Hollik, W.; Kernreiter, T.; Maniatis, M.; von Manteuffel, A.; Martyn, H.U.; Miller, D.J.; Moortgat-Pick, Gudrid A.; Muhlleitner, M.; Nauenberg, U.; Kluge, Hannelies; Porod, W.; Sola, J.; Sopczak, A.; Stahl, A.; Weber, M.M.; Zerwas, P.M.

    2002-01-01

    At future e+- e- linear colliders, the event rates and clean signals of scalar fermion production - in particular for the scalar leptons - allow very precise measurements of their masses and couplings and the determination of their quantum numbers. Various methods are proposed for extracting these parameters from the data at the sfermion thresholds and in the continuum. At the same time, NLO radiative corrections and non-zero width effects have been calculated in order to match the experimental accuracy. The substantial mixing expected for the third generation sfermions opens up additional opportunities. Techniques are presented for determining potential CP-violating phases and for extracting tan(beta) from the stau sector, in particular at high values. The consequences of possible large mass differences in the stop and sbottom system are explored in dedicated analyses.

  8. Electroweak effective couplings for future precision experiments

    International Nuclear Information System (INIS)

    Jegerlehner, F.

    2011-01-01

    The leading hadronic effects in electroweak theory derive from vacuum polarization which are non-perturbative hadronic contributions to the running of the gauge couplings, the electromagnetic α em (s)and the SU(2) L coupling α 2 (s). I will report on my recent package alphaQED, which besides the effective fine structure constant α em (s) also allows for a fairly precise calculation of the SU(2) L gauge coupling α 2 (s). I will briefly review the role, future requirements and possibilities. Applied together with the R had package by Harlander and Steinhauser, the package allows to calculate all SM running couplings as well as running sin 2 Θ versions with state-of-the-art accuracy.

  9. Electroweak effective couplings for future precision experiments

    International Nuclear Information System (INIS)

    Jegerlehner, F.; Humboldt-Universitaet, Berlin

    2011-07-01

    The leading hadronic effects in electroweak theory derive from vacuum polarization which are non-perturbative hadronic contributions to the running of the gauge couplings, the electromagnetic α em (s) and the SU(2) L coupling α 2 (s). I report on my recent package alphaQED [1], which besides the effective fine structure constant α em (s) also allows for a fairly precise calculation of the SU(2) L gauge coupling α 2 (s). I will briefly review the role, future requirements and possibilities. Applied together with the Rhad package by Harlander and Steinhauser [2], the package allows to calculate all SM running couplings as well as running sin 2 Θ versions with state-of-the-art accuracy. (orig.)

  10. Sfermion precision measurements at a linear collider

    International Nuclear Information System (INIS)

    Freitas, A.; Ananthanarayan, B.; Bartl, A.; Blair, G.; Bloechinger, C.; Boos, E.; Brandenburg, A.; Datta, A.; Djouadi, A.; Fraas, H.; Guasch, J.; Hesselbach, S.; Hidaka, K.; Hollik, W.; Kernreiter, T.; Maniatis, M.; Manteuffel, A. von; Martyn, H.-U.; Miller, D.J.; Moortgat-Pick, G.; Muehlleitner, M.; Nauenberg, U.; Nowak, H.; Porod, W.; Sola, J.; Sopczak, A.; Stahl, A.; Weber, M.M.; Zerwas, P.M.

    2003-01-01

    At prospective e ± e - linear colliders, the large cross-sections and clean signals of scalar fermion production--in particular for the scalar leptons - allow very precise measurements of their masses and couplings and the determination of their quantum numbers. Various methods are proposed for extracting these parameters from the data at the sfermion thresholds and in the continuum. At the same time, NLO radiative corrections and non-zero width effects have been calculated in order to match the experimental accuracy. The substantial mixing expected in the third generation opens up additional opportunities. Techniques are presented for determining potential CP-violating phases and for extracting tan β from the stau sector, in particular at high values. The consequences of possible large mass differences in the stop and sbottom system are explored in dedicated analyses

  11. Sfermion precision measurements at a linear collider

    International Nuclear Information System (INIS)

    Freitas, A.

    2003-01-01

    At future e + e - linear colliders, the event rates and clean signals of scalar fermion production--in particular for the scalar leptons--allow very precise measurements of their masses and couplings and the determination of their quantum numbers. Various methods are proposed for extracting these parameters from the data at the sfermion thresholds and in the continuum. At the same time, NLO radiative corrections and non-zero width effects have been calculated in order to match the experimental accuracy. The substantial mixing expected for the third generation sfermions opens up additional opportunities. Techniques are presented for determining potential CP-violating phases and for extracting tan β from the stau sector, in particular at high values. The consequences of possible large mass differences in the stop and sbottom system are explored in dedicated analyses

  12. High-precision radiocarbon chronometry of ancient Egypt, and comparisons with Nubia, Palestine and Mesopotamia

    Energy Technology Data Exchange (ETDEWEB)

    Hassan, F A; Robinson, S W

    1987-03-01

    The use of radiocarbon age measurements in historical chronology is examined for ancient Egypt and neighbouring regions. A methodology is presented aimed at improving the reliability and precision of radiocarbon age determinations.

  13. Lung Cancer Precision Medicine Trials

    Science.gov (United States)

    Patients with lung cancer are benefiting from the boom in targeted and immune-based therapies. With a series of precision medicine trials, NCI is keeping pace with the rapidly changing treatment landscape for lung cancer.

  14. Precision engineering: an evolutionary perspective.

    Science.gov (United States)

    Evans, Chris J

    2012-08-28

    Precision engineering is a relatively new name for a technology with roots going back over a thousand years; those roots span astronomy, metrology, fundamental standards, manufacturing and money-making (literally). Throughout that history, precision engineers have created links across disparate disciplines to generate innovative responses to society's needs and wants. This review combines historical and technological perspectives to illuminate precision engineering's current character and directions. It first provides us a working definition of precision engineering and then reviews the subject's roots. Examples will be given showing the contributions of the technology to society, while simultaneously showing the creative tension between the technological convergence that spurs new directions and the vertical disintegration that optimizes manufacturing economics.

  15. How GNSS Enables Precision Farming

    Science.gov (United States)

    2014-12-01

    Precision farming: Feeding a Growing Population Enables Those Who Feed the World. Immediate and Ongoing Needs - population growth (more to feed) - urbanization (decrease in arable land) Double food production by 2050 to meet world demand. To meet thi...

  16. Electroweak precision observables in the minimal supersymmetric standard model

    International Nuclear Information System (INIS)

    Heinemeyer, S.; Hollik, W.; Weiglein, G.

    2006-01-01

    The current status of electroweak precision observables in the Minimal Supersymmetric Standard Model (MSSM) is reviewed. We focus in particular on the W boson mass, M W , the effective leptonic weak mixing angle, sin 2 θ eff , the anomalous magnetic moment of the muon (g-2) μ , and the lightest CP-even MSSM Higgs boson mass, m h . We summarize the current experimental situation and the status of the theoretical evaluations. An estimate of the current theoretical uncertainties from unknown higher-order corrections and from the experimental errors of the input parameters is given. We discuss future prospects for both the experimental accuracies and the precision of the theoretical predictions. Confronting the precision data with the theory predictions within the unconstrained MSSM and within specific SUSY-breaking scenarios, we analyse how well the data are described by the theory. The mSUGRA scenario with cosmological constraints yields a very good fit to the data, showing a clear preference for a relatively light mass scale of the SUSY particles. The constraints on the parameter space from the precision data are discussed, and it is shown that the prospective accuracy at the next generation of colliders will enhance the sensitivity of the precision tests very significantly

  17. Methodologies of Uncertainty Propagation Calculation

    International Nuclear Information System (INIS)

    Chojnacki, Eric

    2002-01-01

    After recalling the theoretical principle and the practical difficulties of the methodologies of uncertainty propagation calculation, the author discussed how to propagate input uncertainties. He said there were two kinds of input uncertainty: - variability: uncertainty due to heterogeneity, - lack of knowledge: uncertainty due to ignorance. It was therefore necessary to use two different propagation methods. He demonstrated this in a simple example which he generalised, treating the variability uncertainty by the probability theory and the lack of knowledge uncertainty by the fuzzy theory. He cautioned, however, against the systematic use of probability theory which may lead to unjustifiable and illegitimate precise answers. Mr Chojnacki's conclusions were that the importance of distinguishing variability and lack of knowledge increased as the problem was getting more and more complex in terms of number of parameters or time steps, and that it was necessary to develop uncertainty propagation methodologies combining probability theory and fuzzy theory

  18. Engineering radioecology: Methodological considerations

    International Nuclear Information System (INIS)

    Nechaev, A.F.; Projaev, V.V.; Sobolev, I.A.; Dmitriev, S.A.

    1995-01-01

    The term ''radioecology'' has been widely recognized in scientific and technical societies. At the same time, this scientific school (radioecology) does not have a precise/generally acknowledged structure, unified methodical basis, fixed subjects of investigation, etc. In other words, radioecology is a vast, important but rather amorphous conglomerate of various ideas, amalgamated mostly by their involvement in biospheric effects of ionizing radiation and some conceptual stereotypes. This paradox was acceptable up to a certain time. However, with the termination of the Cold War and because of remarkable political changes in the world, it has become possible to convert the problem of environmental restoration from the scientific sphere in particularly practical terms. Already the first steps clearly showed an imperfection of existing technologies, managerial and regulatory schemes; lack of qualified specialists, relevant methods and techniques; uncertainties in methodology of decision-making, etc. Thus, building up (or maybe, structuring) of special scientific and technological basis, which the authors call ''engineering radioecology'', seems to be an important task. In this paper they endeavored to substantiate the last thesis and to suggest some preliminary ideas concerning the subject matter of engineering radioecology

  19. FROM PERSONALIZED TO PRECISION MEDICINE

    Directory of Open Access Journals (Sweden)

    K. V. Raskina

    2017-01-01

    Full Text Available The need to maintain a high quality of life against a backdrop of its inevitably increasing duration is one of the main problems of modern health care. The concept of "right drug to the right patient at the right time", which at first was bearing the name "personalized", is currently unanimously approved by international scientific community as "precision medicine". Precision medicine takes all the individual characteristics into account: genes diversity, environment, lifestyles, and even bacterial microflora and also involves the use of the latest technological developments, which serves to ensure that each patient gets assistance fitting his state best. In the United States, Canada and France national precision medicine programs have already been submitted and implemented. The aim of this review is to describe the dynamic integration of precision medicine methods into routine medical practice and life of modern society. The new paradigm prospects description are complemented by figures, proving the already achieved success in the application of precise methods for example, the targeted therapy of cancer. All in all, the presence of real-life examples, proving the regularity of transition to a new paradigm, and a wide range  of technical and diagnostic capabilities available and constantly evolving make the all-round transition to precision medicine almost inevitable.

  20. Clinical trial methodology

    National Research Council Canada - National Science Library

    Peace, Karl E; Chen, Ding-Geng

    2011-01-01

    ... in the pharmaceutical industry, Clinical trial methodology emphasizes the importance of statistical thinking in clinical research and presents the methodology as a key component of clinical research...

  1. Feasibility and diagnostic accuracy of Ecg-gated SPECT myocardial perfusion imaging by a two-hour protocol: The Myofast study;Faisabilite et precision diagnostique d'un protocole de scintigraphie myocardique synchronisee a l'ECG en deux heures: l'etude Myofast

    Energy Technology Data Exchange (ETDEWEB)

    Dunet, V.; Costo, S.; Sabatier, R.; Grollier, G.; Bouvard, G.; Agostini, D. [CHU Cote-de-Nacre, Service de medecine nucleaire, 14 - Caen (France)

    2010-04-15

    Aim of the study: To assess the feasibility of early stress and rest myocardial perfusion and function study using a fast {sup 99m}Tc-tetrofosmin gated-SPECT protocol in patients with known coronary artery disease. Materials and methods: Forty-three patients (pts) (37 M, 6 F, mean age 63.8 +- 9.8 years) underwent a {sup 99m}Tc-Tetrofosmin gated-SPECT (Axis Picker-Philips) myocardial study and a coronary angiography (C.A.) within 3 months. Images were acquired (LEHR, eight bins, 40 sec per image) after injection of {sup 99m}Tc-tetrofosmin (200 to 380 MBq) early (15 min) post-stress (36 dipyridamole, two dobutamine and five ergo-metric stress), and at rest after {sup 99m}Tc-tetrofosmin reinjection (600 to 1150 MBq), in a total time not exceeding 2 hours. Processing was performed with Q.G.S. software using the 17-segment model. Pathological study was defined as a summed difference score (SDS) greater than or equal to 4 4, a fixed defect with summed rest score greater than or equal to 4 and/or L.V. dysfunction defined as myocardial stunning (variation between stress and rest L.V.E.F. greater than or equal to 4 5%), stress L.V.E.F. less than or equal to 45% or rest L.V.E.F. less than or equal to 40%. Results were compared with C.A., and stenosis greater than or equal to 4 50% was considered as significant. Results: For 100% the quality of SPECT imaging was good or excellent. For six patients gating was impossible because of arrhythmia. The overall sensitivity, specificity and accuracy were 95%, 50%, and 91%, respectively. The concordance between gated SPECT and C.A. was moderate (kappa = 0.45, S.E. = 0.15). Interestingly, early-gated acquisition permitted to underline left ventricular dysfunction in 11 cases (30%), of whom eight had poly vascular disease. Stunning was detected in six of 37 cases (16%), of whom six had poly vascular disease. Conclusion: A one-day two-hour {sup 99m}Tc-tetrofosmin gated-SPECT protocol to assess left ventricular perfusion and function is

  2. A precision synchrotron radiation detector using phosphorescent screens

    International Nuclear Information System (INIS)

    Jung, C.K.; Lateur, M.; Nash, J.; Tinsman, J.; Butler, J.; Wormser, G.

    1990-01-01

    A precision detector to measure synchrotron radiation beam positions has been designed and installed as part of beam energy spectrometers at the Stanford Linear Collider (SLC). The distance between pairs of synchrotron radiation beams is measured absolutely to better than 28 μm on a pulse-to-pulse basis. This contributes less than 5 MeV to the error in the measurement of SLC beam energies (approximately 50 GeV). A system of high-resolution video cameras viewing precisely aligned fiducial wire arrays overlaying phosphorescent screens has achieved this accuracy. 3 refs., 5 figs., 1 tab

  3. Error Estimation and Accuracy Improvements in Nodal Transport Methods

    International Nuclear Information System (INIS)

    Zamonsky, O.M.

    2000-01-01

    The accuracy of the solutions produced by the Discrete Ordinates neutron transport nodal methods is analyzed.The obtained new numerical methodologies increase the accuracy of the analyzed scheems and give a POSTERIORI error estimators. The accuracy improvement is obtained with new equations that make the numerical procedure free of truncation errors and proposing spatial reconstructions of the angular fluxes that are more accurate than those used until present. An a POSTERIORI error estimator is rigurously obtained for one dimensional systems that, in certain type of problems, allows to quantify the accuracy of the solutions. From comparisons with the one dimensional results, an a POSTERIORI error estimator is also obtained for multidimensional systems. LOCAL indicators, which quantify the spatial distribution of the errors, are obtained by the decomposition of the menctioned estimators. This makes the proposed methodology suitable to perform adaptive calculations. Some numerical examples are presented to validate the theoretical developements and to illustrate the ranges where the proposed approximations are valid

  4. Near-real-time regional troposphere models for the GNSS precise point positioning technique

    International Nuclear Information System (INIS)

    Hadas, T; Kaplon, J; Bosy, J; Sierny, J; Wilgan, K

    2013-01-01

    The GNSS precise point positioning (PPP) technique requires high quality product (orbits and clocks) application, since their error directly affects the quality of positioning. For real-time purposes it is possible to utilize ultra-rapid precise orbits and clocks which are disseminated through the Internet. In order to eliminate as many unknown parameters as possible, one may introduce external information on zenith troposphere delay (ZTD). It is desirable that the a priori model is accurate and reliable, especially for real-time application. One of the open problems in GNSS positioning is troposphere delay modelling on the basis of ground meteorological observations. Institute of Geodesy and Geoinformatics of Wroclaw University of Environmental and Life Sciences (IGG WUELS) has developed two independent regional troposphere models for the territory of Poland. The first one is estimated in near-real-time regime using GNSS data from a Polish ground-based augmentation system named ASG-EUPOS established by Polish Head Office of Geodesy and Cartography (GUGiK) in 2008. The second one is based on meteorological parameters (temperature, pressure and humidity) gathered from various meteorological networks operating over the area of Poland and surrounding countries. This paper describes the methodology of both model calculation and verification. It also presents results of applying various ZTD models into kinematic PPP in the post-processing mode using Bernese GPS Software. Positioning results were used to assess the quality of the developed models during changing weather conditions. Finally, the impact of model application to simulated real-time PPP on precision, accuracy and convergence time is discussed. (paper)

  5. High precision innovative micropump for artificial pancreas

    Science.gov (United States)

    Chappel, E.; Mefti, S.; Lettieri, G.-L.; Proennecke, S.; Conan, C.

    2014-03-01

    The concept of artificial pancreas, which comprises an insulin pump, a continuous glucose meter and a control algorithm, is a major step forward in managing patient with type 1 diabetes mellitus. The stability of the control algorithm is based on short-term precision micropump to deliver rapid-acting insulin and to specific integrated sensors able to monitor any failure leading to a loss of accuracy. Debiotech's MEMS micropump, based on the membrane pump principle, is made of a stack of 3 silicon wafers. The pumping chamber comprises a pillar check-valve at the inlet, a pumping membrane which is actuated against stop limiters by a piezo cantilever, an anti-free-flow outlet valve and a pressure sensor. The micropump inlet is tightly connected to the insulin reservoir while the outlet is in direct communication with the patient skin via a cannula. To meet the requirement of a pump dedicated to closed-loop application for diabetes care, in addition to the well-controlled displacement of the pumping membrane, the high precision of the micropump is based on specific actuation profiles that balance effect of pump elasticity in low-consumption push-pull mode.

  6. Precise Point Positioning with Partial Ambiguity Fixing.

    Science.gov (United States)

    Li, Pan; Zhang, Xiaohong

    2015-06-10

    Reliable and rapid ambiguity resolution (AR) is the key to fast precise point positioning (PPP). We propose a modified partial ambiguity resolution (PAR) method, in which an elevation and standard deviation criterion are first used to remove the low-precision ambiguity estimates for AR. Subsequently the success rate and ratio-test are simultaneously used in an iterative process to increase the possibility of finding a subset of decorrelated ambiguities which can be fixed with high confidence. One can apply the proposed PAR method to try to achieve an ambiguity-fixed solution when full ambiguity resolution (FAR) fails. We validate this method using data from 450 stations during DOY 021 to 027, 2012. Results demonstrate the proposed PAR method can significantly shorten the time to first fix (TTFF) and increase the fixing rate. Compared with FAR, the average TTFF for PAR is reduced by 14.9% for static PPP and 15.1% for kinematic PPP. Besides, using the PAR method, the average fixing rate can be increased from 83.5% to 98.2% for static PPP, from 80.1% to 95.2% for kinematic PPP respectively. Kinematic PPP accuracy with PAR can also be significantly improved, compared to that with FAR, due to a higher fixing rate.

  7. Golden Jubilee photos: Precision is their motto

    CERN Multimedia

    2004-01-01

    At the beginning of the 1980s, CERN embarked on the enormous Large Electron-Positron Collider construction project. The excavation of the 27-kilometre LEP tunnel was a huge technical challenge. The tunnel-boring machines excavated the tunnel in 3.3 km octants and had to be operated with extraordinary precision to ensure that they reached their destination - the bottom of the next vertical shaft - precisely on target. The tunnel was excavated before high-performance instruments were developed for the construction of the Channel Tunnel. As no firms were willing to perform the surveying work, CERN's own surveyors, with experience from the SPS behind them, took up the challenge. At the surface, the surveyors established the world's most accurate geodetic network, performing measurements to an accuracy of 10-7, or 1mm per 10 km, using the Terrameter (see photo). The excavation of the tunnel was completed in 1988 and the finished tunnel's trajectory was found to diverge from the theoretical value specified by the...

  8. Accuracy optimization with wavelength tunability in overlay imaging technology

    Science.gov (United States)

    Lee, Honggoo; Kang, Yoonshik; Han, Sangjoon; Shim, Kyuchan; Hong, Minhyung; Kim, Seungyoung; Lee, Jieun; Lee, Dongyoung; Oh, Eungryong; Choi, Ahlin; Kim, Youngsik; Marciano, Tal; Klein, Dana; Hajaj, Eitan M.; Aharon, Sharon; Ben-Dov, Guy; Lilach, Saltoun; Serero, Dan; Golotsvan, Anna

    2018-03-01

    As semiconductor manufacturing technology progresses and the dimensions of integrated circuit elements shrink, overlay budget is accordingly being reduced. Overlay budget closely approaches the scale of measurement inaccuracies due to both optical imperfections of the measurement system and the interaction of light with geometrical asymmetries of the measured targets. Measurement inaccuracies can no longer be ignored due to their significant effect on the resulting device yield. In this paper we investigate a new approach for imaging based overlay (IBO) measurements by optimizing accuracy rather than contrast precision, including its effect over the total target performance, using wavelength tunable overlay imaging metrology. We present new accuracy metrics based on theoretical development and present their quality in identifying the measurement accuracy when compared to CD-SEM overlay measurements. The paper presents the theoretical considerations and simulation work, as well as measurement data, for which tunability combined with the new accuracy metrics is shown to improve accuracy performance.

  9. Design of precision position adjustable scoop

    International Nuclear Information System (INIS)

    Li Zhili; Zhang Kai; Dong Jinping

    2014-01-01

    In isotopes separation technologies, the centrifuge method has been the most popular technology now. Separation performance of centrifugal machines is greatly influenced by the flow field in the centrifugal machines. And the position of scoops in the centrifuges has a significant influence on the flow field. To obtain a better flow field characteristic and find the best position of scoops in the centrifuges, a position adjustable scoop system was studied. A micro stage and a linear encoder were used in the system to improve the position accuracy of the scoop. Eddy current sensors had been used in a position calibration measurement. The measurement result showed the sensitivity and stability of the position system could meet the performance expectation. But as the driving mean, the steel wire and pulley limit the control precision. On the basis of this scheme, an ultrasonic motor was used as driving mean. Experimental results showed the control accuracy was improved. This scheme laid a foundation to obtain internal flow field parameters of centrifuge and get the optimal feeding tube position. (authors)

  10. Comparison of three hand dynamometers in relation to the accuracy and precision of the measurements Comparação de três dinamômetros de preensão manual relacionados à exatidão e precisão das medidas

    Directory of Open Access Journals (Sweden)

    Josária F. Amaral

    2012-06-01

    Full Text Available BACKGROUND: Given the variety of available hand-held dynamometers and their different handle shapes, reliability studies are needed. Objectives: To compare the accuracy and reliability between three different hand-held dynamometers and analyze the influence of their handles on grip strength. Methods: The tests were performed with the Jamar® dynamometer, the Takei® dynamometer and the EMG System Manual Transducer with modified handle. Eighteen healthy volunteers aged 20.0±1.3 years without history of musculoskeletal disorders or trauma in the evaluated limbs were included. Data normality was tested using the Shapiro-Wilk test. To verify possible differences between the dynamometers, repeated measures ANOVA was administered, followed by Tukey post-hoc tests. Reliability between measurements was evaluated using intraclass correlation coefficient (ICC and agreement was tested using Bland and Altman plots. The dynamometers calibration process was evaluated using linear regressions. RESULTS: We observed statistically significant differences on the female group between the Jamar® and the Takei® dynamometers (females pCONTEXTUALIZAÇÃO: Dada a variedade de dinamômetros disponíveis para mensurar a força de preensão manual com diferentes formatos de empunhaduras, estudos de confiabilidade fazem-se necessários. Objetivos: Comparar a exatidão e a precisão das medidas de três dinamômetros distintos e analisar a influência do perfil de empunhadura de cada um. MÉTODOS: Os testes foram realizados com os dinamômetros Jamar®, Takei® e o Transdutor Manual EMG System com empunhadura modificada. Foram avaliados 18 voluntários saudáveis, com idade de 20±1,3 anos, sem histórico de doença musculoesquelética ou traumas nos membros avaliados. A normalidade dos dados foi testada por meio do teste Shapiro-Wilk. Para verificar as possíveis diferenças entre as medições dos dinamômetros, aplicou-se uma ANOVA para medidas repetidas seguida do

  11. Improving the accuracy of dynamic mass calculation

    Directory of Open Access Journals (Sweden)

    Oleksandr F. Dashchenko

    2015-06-01

    Full Text Available With the acceleration of goods transporting, cargo accounting plays an important role in today's global and complex environment. Weight is the most reliable indicator of the materials control. Unlike many other variables that can be measured indirectly, the weight can be measured directly and accurately. Using strain-gauge transducers, weight value can be obtained within a few milliseconds; such values correspond to the momentary load, which acts on the sensor. Determination of the weight of moving transport is only possible by appropriate processing of the sensor signal. The aim of the research is to develop a methodology for weighing freight rolling stock, which increases the accuracy of the measurement of dynamic mass, in particular wagon that moves. Apart from time-series methods, preliminary filtration for improving the accuracy of calculation is used. The results of the simulation are presented.

  12. A Methodology to Assess Ionospheric Models for GNSS

    Science.gov (United States)

    Rovira-Garcia, Adria; Juan, José Miguel; Sanz, Jaume; González-Casado, Guillermo; Ibánez, Deimos

    2015-04-01

    included in the navigation messages of GPS or Galileo. On the other hand, the new gAGE/UPC GIM is shown to be several times more accurate than the previously mentioned IGS-GIMs or EGNOS grid models. The results of this assessment suggest that current ionospheric models can be improved by using the methodology proposed in this work in conjunction with a precise STEC determination, such as the GIMs calculated by the gAGE/UPC research group. The findings underline that the temporal resolution of the techniques considered does not solely explain the different performances. In fact, it is shown how the adequate (and sometimes subtle) use of the relevant parameters to the ionospheric modelling determines the accuracy.

  13. Reliability and precision of pellet-group counts for estimating landscape-level deer density

    Science.gov (United States)

    David S. deCalesta

    2013-01-01

    This study provides hitherto unavailable methodology for reliably and precisely estimating deer density within forested landscapes, enabling quantitative rather than qualitative deer management. Reliability and precision of the deer pellet-group technique were evaluated in 1 small and 2 large forested landscapes. Density estimates, adjusted to reflect deer harvest and...

  14. Nanomaterials for Cancer Precision Medicine.

    Science.gov (United States)

    Wang, Yilong; Sun, Shuyang; Zhang, Zhiyuan; Shi, Donglu

    2018-04-01

    Medical science has recently advanced to the point where diagnosis and therapeutics can be carried out with high precision, even at the molecular level. A new field of "precision medicine" has consequently emerged with specific clinical implications and challenges that can be well-addressed by newly developed nanomaterials. Here, a nanoscience approach to precision medicine is provided, with a focus on cancer therapy, based on a new concept of "molecularly-defined cancers." "Next-generation sequencing" is introduced to identify the oncogene that is responsible for a class of cancers. This new approach is fundamentally different from all conventional cancer therapies that rely on diagnosis of the anatomic origins where the tumors are found. To treat cancers at molecular level, a recently developed "microRNA replacement therapy" is applied, utilizing nanocarriers, in order to regulate the driver oncogene, which is the core of cancer precision therapeutics. Furthermore, the outcome of the nanomediated oncogenic regulation has to be accurately assessed by the genetically characterized, patient-derived xenograft models. Cancer therapy in this fashion is a quintessential example of precision medicine, presenting many challenges to the materials communities with new issues in structural design, surface functionalization, gene/drug storage and delivery, cell targeting, and medical imaging. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Precision Medicine and Men's Health.

    Science.gov (United States)

    Mata, Douglas A; Katchi, Farhan M; Ramasamy, Ranjith

    2017-07-01

    Precision medicine can greatly benefit men's health by helping to prevent, diagnose, and treat prostate cancer, benign prostatic hyperplasia, infertility, hypogonadism, and erectile dysfunction. For example, precision medicine can facilitate the selection of men at high risk for prostate cancer for targeted prostate-specific antigen screening and chemoprevention administration, as well as assist in identifying men who are resistant to medical therapy for prostatic hyperplasia, who may instead require surgery. Precision medicine-trained clinicians can also let couples know whether their specific cause of infertility should be bypassed by sperm extraction and in vitro fertilization to prevent abnormalities in their offspring. Though precision medicine's role in the management of hypogonadism has yet to be defined, it could be used to identify biomarkers associated with individual patients' responses to treatment so that appropriate therapy can be prescribed. Last, precision medicine can improve erectile dysfunction treatment by identifying genetic polymorphisms that regulate response to medical therapies and by aiding in the selection of patients for further cardiovascular disease screening.

  16. Precision Medicine in Gastrointestinal Pathology.

    Science.gov (United States)

    Wang, David H; Park, Jason Y

    2016-05-01

    -Precision medicine is the promise of individualized therapy and management of patients based on their personal biology. There are now multiple global initiatives to perform whole-genome sequencing on millions of individuals. In the United States, an early program was the Million Veteran Program, and a more recent proposal in 2015 by the president of the United States is the Precision Medicine Initiative. To implement precision medicine in routine oncology care, genetic variants present in tumors need to be matched with effective clinical therapeutics. When we focus on the current state of precision medicine for gastrointestinal malignancies, it becomes apparent that there is a mixed history of success and failure. -To present the current state of precision medicine using gastrointestinal oncology as a model. We will present currently available targeted therapeutics, promising new findings in clinical genomic oncology, remaining quality issues in genomic testing, and emerging oncology clinical trial designs. -Review of the literature including clinical genomic studies on gastrointestinal malignancies, clinical oncology trials on therapeutics targeted to molecular alterations, and emerging clinical oncology study designs. -Translating our ability to sequence thousands of genes into meaningful improvements in patient survival will be the challenge for the next decade.

  17. High accuracy wavelength calibration for a scanning visible spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Scotti, Filippo; Bell, Ronald E. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

    2010-10-15

    Spectroscopic applications for plasma velocity measurements often require wavelength accuracies {<=}0.2 A. An automated calibration, which is stable over time and environmental conditions without the need to recalibrate after each grating movement, was developed for a scanning spectrometer to achieve high wavelength accuracy over the visible spectrum. This method fits all relevant spectrometer parameters using multiple calibration spectra. With a stepping-motor controlled sine drive, an accuracy of {approx}0.25 A has been demonstrated. With the addition of a high resolution (0.075 arc sec) optical encoder on the grating stage, greater precision ({approx}0.005 A) is possible, allowing absolute velocity measurements within {approx}0.3 km/s. This level of precision requires monitoring of atmospheric temperature and pressure and of grating bulk temperature to correct for changes in the refractive index of air and the groove density, respectively.

  18. High accuracy FIONA-AFM hybrid imaging

    International Nuclear Information System (INIS)

    Fronczek, D.N.; Quammen, C.; Wang, H.; Kisker, C.; Superfine, R.; Taylor, R.; Erie, D.A.; Tessmer, I.

    2011-01-01

    Multi-protein complexes are ubiquitous and play essential roles in many biological mechanisms. Single molecule imaging techniques such as electron microscopy (EM) and atomic force microscopy (AFM) are powerful methods for characterizing the structural properties of multi-protein and multi-protein-DNA complexes. However, a significant limitation to these techniques is the ability to distinguish different proteins from one another. Here, we combine high resolution fluorescence microscopy and AFM (FIONA-AFM) to allow the identification of different proteins in such complexes. Using quantum dots as fiducial markers in addition to fluorescently labeled proteins, we are able to align fluorescence and AFM information to ≥8 nm accuracy. This accuracy is sufficient to identify individual fluorescently labeled proteins in most multi-protein complexes. We investigate the limitations of localization precision and accuracy in fluorescence and AFM images separately and their effects on the overall registration accuracy of FIONA-AFM hybrid images. This combination of the two orthogonal techniques (FIONA and AFM) opens a wide spectrum of possible applications to the study of protein interactions, because AFM can yield high resolution (5-10 nm) information about the conformational properties of multi-protein complexes and the fluorescence can indicate spatial relationships of the proteins in the complexes. -- Research highlights: → Integration of fluorescent signals in AFM topography with high (<10 nm) accuracy. → Investigation of limitations and quantitative analysis of fluorescence-AFM image registration using quantum dots. → Fluorescence center tracking and display as localization probability distributions in AFM topography (FIONA-AFM). → Application of FIONA-AFM to a biological sample containing damaged DNA and the DNA repair proteins UvrA and UvrB conjugated to quantum dots.

  19. Accuracy of Spindle Units with Hydrostatic Bearings

    Directory of Open Access Journals (Sweden)

    Fedorynenko Dmytro

    2016-06-01

    Full Text Available The work is devoted to the research of precision regularities in a spindle unit by the trajectory of the spindle installed on hydrostatic bearings. The mathematical model of trajectories spindle with lumped parameters that allows to define the position of the spindle with regard the simultaneous influence of design parameters, geometrical deviations ofform, temperature deformation bearing surfaces, the random nature of operational parameters and technical loads of hydrostatic bearings has been developed. Based on the results of numerical modeling the influence of shape errors of bearing surface of hydrostatic bearing on the statistical characteristics of the radius vector trajectories of the spindle by varying the values rotational speed of the spindle and oil pressure in front hydrostatic bearing has been developed. The obtained statistical regularities of precision spindle unit have been confirmed experimentally. It has been shown that an effective way to increase the precision of spindle units is to regulate the size of the gap in hydrostatic spindle bearings. The new design of an adjustable hydrostatic bearing, which can improve the accuracy of regulation size gap has been proposed.

  20. Optimization to improve precision in neutron activation analysis

    International Nuclear Information System (INIS)

    Yustina Tri Handayani

    2010-01-01

    The level of precision or accuracy required in analysis should be satisfied the general requirements and customer needs. In presenting the results of the analysis, the level of precision is expressed as uncertainty. Requirement general is Horwitz prediction. Factors affecting the uncertainty in the Neutron Activation Analysis (NAA) include the mass of sample, mass standards, concentration in standard, count of sample, count of standard and counting geometry. Therefore, to achieve the expected level of precision, these parameters need to be optimized. A standard concentration of similar materials is applied as a basis of calculation. In the calculation NIST SRM 2704 is applied for sediment samples. Mass of sample, irradiation time and cooling time can be modified to obtain the expected uncertainty. The prediction results show the level of precision for Al, V, Mg, Mn, K, Na, As, Cr, Co, Fe, and Zn eligible the Horwitz. The predictive the count and standard deviation for Mg-27 and Zn-65 were higher than the actual value occurred due to overlapping of Mg-27 and Mn-54 peaks and Zn-65 and Fe-59 peaks. Precision level of Ca is greater than the Horwitz, since the value of microscopic cross section, the probability of radiation emission of Ca-49 and gamma spectrometer efficiency at 3084 keV is relatively small. Increased precision can only be done by extending the counting time and multiply the number of samples, because of the fixed value. The prediction results are in accordance with experimental results. (author)

  1. The precision of the NDVI derived from AVHRR observations

    International Nuclear Information System (INIS)

    Roderick, M.; Smith, R.; Cridland, S.

    1996-01-01

    Vegetation studies using NOAA-AVHRR data have tended to focus on the use of the normalized difference vegetation index (NDVI). This unitless index is computed using near-infrared and red reflectances, and thus has both an accuracy and precision. This article reports on a formal statistical framework for assessing the precision of the NDVI derived from NOAA-AVHRR observations. The framework is based on the “best possible” precision concept, which assumes that signal quantization is the only source of observational error. While the radiance resolution of a spectral observation is essentially fixed by the instrument characteristics, the reflectance resolution is the radiance resolution divided by the cosine of the solar zenith angle. Using typical solar zenith angles for AVHRR image acquisitions over Australia, ± 0.01 NDVI units is typically with “best possible” precision attainable in the NDVI, although this degrades significantly over dark targets, and at large solar zenith angles. Transforming the computed NDVI into a single byte for disk storage results in little or no loss of precision. The framework developed in this article can be adapted to estimate the “best possible” precision of other vegetation indices derived using data from other remote sensing satellites. (author)

  2. Ultraprecision Pointing Accuracy for SmallSat/CubeSat Attitude Control Systems, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The primary objective of the Phase I investigation is to develop and demonstrate an innovative solution that can enable very high precision pointing accuracy...

  3. Sensing technologies for precision irrigation

    CERN Document Server

    Ćulibrk, Dubravko; Minic, Vladan; Alonso Fernandez, Marta; Alvarez Osuna, Javier; Crnojevic, Vladimir

    2014-01-01

    This brief provides an overview of state-of-the-art sensing technologies relevant to the problem of precision irrigation, an emerging field within the domain of precision agriculture. Applications of wireless sensor networks, satellite data and geographic information systems in the domain are covered. This brief presents the basic concepts of the technologies and emphasizes the practical aspects that enable the implementation of intelligent irrigation systems. The authors target a broad audience interested in this theme and organize the content in five chapters, each concerned with a specific technology needed to address the problem of optimal crop irrigation. Professionals and researchers will find the text a thorough survey with practical applications.

  4. Precision measurement with atom interferometry

    International Nuclear Information System (INIS)

    Wang Jin

    2015-01-01

    Development of atom interferometry and its application in precision measurement are reviewed in this paper. The principle, features and the implementation of atom interferometers are introduced, the recent progress of precision measurement with atom interferometry, including determination of gravitational constant and fine structure constant, measurement of gravity, gravity gradient and rotation, test of weak equivalence principle, proposal of gravitational wave detection, and measurement of quadratic Zeeman shift are reviewed in detail. Determination of gravitational redshift, new definition of kilogram, and measurement of weak force with atom interferometry are also briefly introduced. (topical review)

  5. ELECTROWEAK PHYSICS AND PRECISION STUDIES

    International Nuclear Information System (INIS)

    MARCIANO, W.

    2005-01-01

    The utility of precision electroweak measurements for predicting the Standard Model Higgs mass via quantum loop effects is discussed. Current values of m W , sin 2 θ W (m Z ) # ovr MS# and m t imply a relatively light Higgs which is below the direct experimental bound but possibly consistent with Supersymmetry expectations. The existence of Supersymmetry is further suggested by a 2σ discrepancy between experiment and theory for the muon anomalous magnetic moment. Constraints from precision studies on other types of ''New Physics'' are also briefly described

  6. Universal precision sine bar attachment

    Science.gov (United States)

    Mann, Franklin D. (Inventor)

    1989-01-01

    This invention relates to an attachment for a sine bar which can be used to perform measurements during lathe operations or other types of machining operations. The attachment can be used for setting precision angles on vises, dividing heads, rotary tables and angle plates. It can also be used in the inspection of machined parts, when close tolerances are required, and in the layout of precision hardware. The novelty of the invention is believed to reside in a specific versatile sine bar attachment for measuring a variety of angles on a number of different types of equipment.

  7. A Dynamic Precision Evaluation Method for the Star Sensor in the Stellar-Inertial Navigation System.

    Science.gov (United States)

    Lu, Jiazhen; Lei, Chaohua; Yang, Yanqiang

    2017-06-28

    Integrating the advantages of INS (inertial navigation system) and the star sensor, the stellar-inertial navigation system has been used for a wide variety of applications. The star sensor is a high-precision attitude measurement instrument; therefore, determining how to validate its accuracy is critical in guaranteeing its practical precision. The dynamic precision evaluation of the star sensor is more difficult than a static precision evaluation because of dynamic reference values and other impacts. This paper proposes a dynamic precision verification method of star sensor with the aid of inertial navigation device to realize real-time attitude accuracy measurement. Based on the gold-standard reference generated by the star simulator, the altitude and azimuth angle errors of the star sensor are calculated for evaluation criteria. With the goal of diminishing the impacts of factors such as the sensors' drift and devices, the innovative aspect of this method is to employ static accuracy for comparison. If the dynamic results are as good as the static results, which have accuracy comparable to the single star sensor's precision, the practical precision of the star sensor is sufficiently high to meet the requirements of the system specification. The experiments demonstrate the feasibility and effectiveness of the proposed method.

  8. High precision ray tracing in cylindrically symmetric electrostatics

    Energy Technology Data Exchange (ETDEWEB)

    Edwards Jr, David, E-mail: dej122842@gmail.com

    2015-11-15

    Highlights: • High precision ray tracing is formulated using power series techniques. • Ray tracing is possible for fields generated by solution to laplace's equation. • Spatial and temporal orders of 4–10 are included. • Precisions in test geometries of hemispherical deflector analyzer of ∼10{sup −20} have been obtained. • This solution offers a considerable extension to the ray tracing accuracy over the current state of art. - Abstract: With the recent availability of a high order FDM solution to the curved boundary value problem, it is now possible to determine potentials in such geometries with considerably greater accuracy than had been available with the FDM method. In order for the algorithms used in the accurate potential calculations to be useful in ray tracing, an integration of those algorithms needs to be placed into the ray trace process itself. The object of this paper is to incorporate these algorithms into a solution of the equations of motion of the ray and, having done this, to demonstrate its efficacy. The algorithm incorporation has been accomplished by using power series techniques and the solution constructed has been tested by tracing the medial ray through concentric sphere geometries. The testing has indicated that precisions of ray calculations of 10{sup −20} are now possible. This solution offers a considerable extension to the ray tracing accuracy over the current state of art.

  9. 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....

  10. Meditation experience predicts introspective accuracy.

    Directory of Open Access Journals (Sweden)

    Kieran C R Fox

    Full Text Available The accuracy of subjective reports, especially those involving introspection of one's own internal processes, remains unclear, and research has demonstrated large individual differences in introspective accuracy. It has been hypothesized that introspective accuracy may be heightened in persons who engage in meditation practices, due to the highly introspective nature of such practices. We undertook a preliminary exploration of this hypothesis, examining introspective accuracy in a cross-section of meditation practitioners (1-15,000 hrs experience. Introspective accuracy was assessed by comparing subjective reports of tactile sensitivity for each of 20 body regions during a 'body-scanning' meditation with averaged, objective measures of tactile sensitivity (mean size of body representation area in primary somatosensory cortex; two-point discrimination threshold as reported in prior research. Expert meditators showed significantly better introspective accuracy than novices; overall meditation experience also significantly predicted individual introspective accuracy. These results suggest that long-term meditators provide more accurate introspective reports than novices.

  11. Application of high precision temperature control technology in infrared testing

    Science.gov (United States)

    Cao, Haiyuan; Cheng, Yong; Zhu, Mengzhen; Chu, Hua; Li, Wei

    2017-11-01

    In allusion to the demand of infrared system test, the principle of Infrared target simulator and the function of the temperature control are presented. The key technology of High precision temperature control is discussed, which include temperature gathering, PID control and power drive. The design scheme of temperature gathering is put forward. In order to reduce the measure error, discontinuously current and four-wire connection for the platinum thermal resistance are adopted. A 24-bits AD chip is used to improve the acquisition precision. Fuzzy PID controller is designed because of the large time constant and continuous disturbance of the environment temperature, which result in little overshoot, rapid response, high steady-state accuracy. Double power operational amplifiers are used to drive the TEC. Experiments show that the key performances such as temperature control precision and response speed meet the requirements.

  12. High current precision long pulse electron beam position monitor

    CERN Document Server

    Nelson, S D; Fessenden, T J; Holmes, C

    2000-01-01

    Precision high current long pulse electron beam position monitoring has typically experienced problems with high Q sensors, sensors damped to the point of lack of precision, or sensors that interact substantially with any beam halo thus obscuring the desired signal. As part of the effort to develop a multi-axis electron beam transport system using transverse electromagnetic stripline kicker technology, it is necessary to precisely determine the position and extent of long high energy beams for accurate beam position control (6 - 40 MeV, 1 - 4 kA, 2 μs beam pulse, sub millimeter beam position accuracy.) The kicker positioning system utilizes shot-to-shot adjustments for reduction of relatively slow (< 20 MHz) motion of the beam centroid. The electron beams passing through the diagnostic systems have the potential for large halo effects that tend to corrupt position measurements.

  13. Using Big Data Analytics to Advance Precision Radiation Oncology.

    Science.gov (United States)

    McNutt, Todd R; Benedict, Stanley H; Low, Daniel A; Moore, Kevin; Shpitser, Ilya; Jiang, Wei; Lakshminarayanan, Pranav; Cheng, Zhi; Han, Peijin; Hui, Xuan; Nakatsugawa, Minoru; Lee, Junghoon; Moore, Joseph A; Robertson, Scott P; Shah, Veeraj; Taylor, Russ; Quon, Harry; Wong, John; DeWeese, Theodore

    2018-06-01

    Big clinical data analytics as a primary component of precision medicine is discussed, identifying where these emerging tools fit in the spectrum of genomics and radiomics research. A learning health system (LHS) is conceptualized that uses clinically acquired data with machine learning to advance the initiatives of precision medicine. The LHS is comprehensive and can be used for clinical decision support, discovery, and hypothesis derivation. These developing uses can positively impact the ultimate management and therapeutic course for patients. The conceptual model for each use of clinical data, however, is different, and an overview of the implications is discussed. With advancements in technologies and culture to improve the efficiency, accuracy, and breadth of measurements of the patient condition, the concept of an LHS may be realized in precision radiation therapy. Copyright © 2018 Elsevier Inc. All rights reserved.

  14. Spin and precision electroweak physics

    Energy Technology Data Exchange (ETDEWEB)

    Marciano, W.J. [Brookhaven National Lab., Upton, NY (United States)

    1994-12-01

    A perspective on fundamental parameters and precision tests of the Standard Model is given. Weak neutral current reactions are discussed with emphasis on those processes involving (polarized) electrons. The role of electroweak radiative corrections in determining the top quark mass and probing for {open_quotes}new physics{close_quotes} is described.

  15. Spin and precision electroweak physics

    International Nuclear Information System (INIS)

    Marciano, W.J.

    1993-01-01

    A perspective on fundamental parameters and precision tests of the Standard Model is given. Weak neutral current reactions are discussed with emphasis on those processes involving (polarized) electrons. The role of electroweak radiative corrections in determining the top quark mass and probing for ''new physics'' is described

  16. Precision surveying system for PEP

    International Nuclear Information System (INIS)

    Gunn, J.; Lauritzen, T.; Sah, R.; Pellisier, P.F.

    1977-01-01

    A semi-automatic precision surveying system is being developed for PEP. Reference elevations for vertical alignment will be provided by a liquid level. The short range surveying will be accomplished using a Laser Surveying System featuring automatic data acquisition and analysis

  17. Precision medicine at the crossroads.

    Science.gov (United States)

    Olson, Maynard V

    2017-10-11

    There are bioethical, institutional, economic, legal, and cultural obstacles to creating the robust-precompetitive-data resource that will be required to advance the vision of "precision medicine," the ability to use molecular data to target therapies to patients for whom they offer the most benefit at the least risk. Creation of such an "information commons" was the central recommendation of the 2011 report Toward Precision Medicine issued by a committee of the National Research Council of the USA (Committee on a Framework for Development of a New Taxonomy of Disease; National Research Council. Toward precision medicine: building a knowledge network for biomedical research and a new taxonomy of disease. 2011). In this commentary, I review the rationale for creating an information commons and the obstacles to doing so; then, I endorse a path forward based on the dynamic consent of research subjects interacting with researchers through trusted mediators. I assert that the advantages of the proposed system overwhelm alternative ways of handling data on the phenotypes, genotypes, and environmental exposures of individual humans; hence, I argue that its creation should be the central policy objective of early efforts to make precision medicine a reality.

  18. Proton gyromagnetic precision measurement system

    International Nuclear Information System (INIS)

    Zhu Deming; Deming Zhu

    1991-01-01

    A computerized control and measurement system used in the proton gyromagnetic precision meausrement is descirbed. It adopts the CAMAC data acquisition equipment, using on-line control and analysis with the HP85 and PDP-11/60 computer systems. It also adopts the RSX11M computer operation system, and the control software is written in FORTRAN language

  19. Quantum mechanics and precision measurements

    International Nuclear Information System (INIS)

    Ramsey, N.F.

    1995-01-01

    The accuracies of measurements of almost all fundamental physical constants have increased by factors of about 10000 during the past 60 years. Although some of the improvements are due to greater care, most are due to new techniques based on quantum mechanics. Although the Heisenberg Uncertainty Principle often limits measurement accuracies, in many cases the validity of quantum mechanics makes possible the vastly improved measurement accuracies. Seven quantum features that have a profound influence on the science of measurements are: 1) Existence of discrete quantum states of energy. 2) Energy conservation in transitions between two states. 3) Electromagnetic radiation of frequency v is quantized with energy hv per quantum. 4) The identity principle. 5) The Heisenberg Uncertainty Principle. 6) Addition of probability amplitudes (not probabilities). 7) Wave and coherent phase phenomena. Of these seven quantum features, only the Heisenberg Uncertainty Principle limits the accuracy of measurements, and its effect is often negligibly small. The other six features make possible much more accurate measurements of quantum systems than with almost all classical systems. These effects are discussed and illustrated

  20. New analytical methodology for analysing S(IV) species at low pH solutions by one stage titration method (bichromatometry) with a clear colour change. Could potentially replace the state-of-art-method iodometry at low pH analysis due higher accuracy.

    Science.gov (United States)

    Santasalo-Aarnio, Annukka; Galfi, Istvan; Virtanen, Jorma; Gasik, Michael M

    2017-01-01

    A new, faster and more reliable analytical methodology for S(IV) species analysis at low pH solutions by bichromatometry is proposed. For decades the state of the art methodology has been iodometry that is still well justified method for neutral solutions, thus at low pH media possess various side reactions increasing inaccuracy. In contrast, the new methodology has no side reactions at low pH media, requires only one titration step and provides a clear color change if S(IV) species are present in the solution. The method is validated using model solutions with known concentrations and applied to analyses of gaseous SO2 from purged solution in low pH media samples. The results indicate that bichromatometry can accurately analyze SO2 from liquid samples having pH even below 0 relevant to metallurgical industrial processes.

  1. A novel biamperometric methodology for thorium determination by EDTA complexometric titration

    International Nuclear Information System (INIS)

    Jayachandran, K.; Gamare, J.S.; Nair, P.R.; Xavier, M.; Aggarwal, S.K.

    2012-01-01

    A biamperometric methodology is described for the determination of thorium by EDTA complexometric titration, based on the observed electrochemical behaviour of EDTA when the applied potential was ≥ 200 mV between the twin Pt electrodes. Studies carried out showed that a pH range of 2.4-2.7 was optimum for the determination. Accuracy and precision of the method were evaluated using different amounts of thorium ranging from 50 μg to 5 mg. Studies on the interference of uranium were carried out with different amounts of uranium ranging from 20 to 80% using the presently developed approach of biamperometry as well as the conventional indicator method. The method was employed for the determination of Th in (Th,U)O 2 samples containing different amounts of Th and U. (orig.)

  2. What do we mean by accuracy in geomagnetic measurements?

    Science.gov (United States)

    Green, A.W.

    1990-01-01

    High accuracy is what distinguishes measurements made at the world's magnetic observatories from other types of geomagnetic measurements. High accuracy in determining the absolute values of the components of the Earth's magnetic field is essential to studying geomagnetic secular variation and processes at the core mantle boundary, as well as some magnetospheric processes. In some applications of geomagnetic data, precision (or resolution) of measurements may also be important. In addition to accuracy and resolution in the amplitude domain, it is necessary to consider these same quantities in the frequency and space domains. New developments in geomagnetic instruments and communications make real-time, high accuracy, global geomagnetic observatory data sets a real possibility. There is a growing realization in the scientific community of the unique relevance of geomagnetic observatory data to the principal contemporary problems in solid Earth and space physics. Together, these factors provide the promise of a 'renaissance' of the world's geomagnetic observatory system. ?? 1990.

  3. Precision electroweak physics at LEP

    Energy Technology Data Exchange (ETDEWEB)

    Mannelli, M.

    1994-12-01

    Copious event statistics, a precise understanding of the LEP energy scale, and a favorable experimental situation at the Z{sup 0} resonance have allowed the LEP experiments to provide both dramatic confirmation of the Standard Model of strong and electroweak interactions and to place substantially improved constraints on the parameters of the model. The author concentrates on those measurements relevant to the electroweak sector. It will be seen that the precision of these measurements probes sensitively the structure of the Standard Model at the one-loop level, where the calculation of the observables measured at LEP is affected by the value chosen for the top quark mass. One finds that the LEP measurements are consistent with the Standard Model, but only if the mass of the top quark is measured to be within a restricted range of about 20 GeV.

  4. Environment-assisted precision measurement

    DEFF Research Database (Denmark)

    Goldstein, G.; Cappellaro, P.; Maze, J. R.

    2011-01-01

    We describe a method to enhance the sensitivity of precision measurements that takes advantage of the environment of a quantum sensor to amplify the response of the sensor to weak external perturbations. An individual qubit is used to sense the dynamics of surrounding ancillary qubits, which...... are in turn affected by the external field to be measured. The resulting sensitivity enhancement is determined by the number of ancillas that are coupled strongly to the sensor qubit; it does not depend on the exact values of the coupling strengths and is resilient to many forms of decoherence. The method...... achieves nearly Heisenberg-limited precision measurement, using a novel class of entangled states. We discuss specific applications to improve clock sensitivity using trapped ions and magnetic sensing based on electronic spins in diamond...

  5. Precise object tracking under deformation

    International Nuclear Information System (INIS)

    Saad, M.H

    2010-01-01

    The precise object tracking is an essential issue in several serious applications such as; robot vision, automated surveillance (civil and military), inspection, biomedical image analysis, video coding, motion segmentation, human-machine interface, visualization, medical imaging, traffic systems, satellite imaging etc. This frame-work focuses on the precise object tracking under deformation such as scaling , rotation, noise, blurring and change of illumination. This research is a trail to solve these serious problems in visual object tracking by which the quality of the overall system will be improved. Developing a three dimensional (3D) geometrical model to determine the current pose of an object and predict its future location based on FIR model learned by the OLS. This framework presents a robust ranging technique to track a visual target instead of the traditional expensive ranging sensors. The presented research work is applied to real video stream and achieved high precession results.

  6. Fit to Electroweak Precision Data

    International Nuclear Information System (INIS)

    Erler, Jens

    2006-01-01

    A brief review of electroweak precision data from LEP, SLC, the Tevatron, and low energies is presented. The global fit to all data including the most recent results on the masses of the top quark and the W boson reinforces the preference for a relatively light Higgs boson. I will also give an outlook on future developments at the Tevatron Run II, CEBAF, the LHC, and the ILC

  7. Precise Object Tracking under Deformation

    International Nuclear Information System (INIS)

    Saad, M.H.

    2010-01-01

    The precise object tracking is an essential issue in several serious applications such as; robot vision, automated surveillance (civil and military), inspection, biomedical image analysis, video coding, motion segmentation, human-machine interface, visualization, medical imaging, traffic systems, satellite imaging etc. This framework focuses on the precise object tracking under deformation such as scaling, rotation, noise, blurring and change of illumination. This research is a trail to solve these serious problems in visual object tracking by which the quality of the overall system will be improved. Developing a three dimensional (3D) geometrical model to determine the current pose of an object and predict its future location based on FIR model learned by the OLS. This framework presents a robust ranging technique to track a visual target instead of the traditional expensive ranging sensors. The presented research work is applied to real video stream and achieved high precession results. xiiiThe precise object tracking is an essential issue in several serious applications such as; robot vision, automated surveillance (civil and military), inspection, biomedical image analysis, video coding, motion segmentation, human-machine interface, visualization, medical imaging, traffic systems, satellite imaging etc. This framework focuses on the precise object tracking under deformation such as scaling, rotation, noise, blurring and change of illumination. This research is a trail to solve these serious problems in visual object tracking by which the quality of the overall system will be improved. Developing a three dimensional (3D) geometrical model to determine the current pose of an object and predict its future location based on FIR model learned by the OLS. This framework presents a robust ranging technique to track a visual target instead of the traditional expensive ranging sensors. The presented research work is applied to real video stream and achieved high

  8. Precision measurements of electroweak parameters

    CERN Document Server

    Savin, Alexander

    2017-01-01

    A set of selected precise measurements of the SM parameters from the LHC experiments is discussed. Results on W-mass measurement and forward-backward asymmetry in production of the Drell--Yan events in both dielectron and dimuon decay channels are presented together with results on the effective mixing angle measurements. Electroweak production of the vector bosons in association with two jets is discussed.

  9. Knowledge of Precision Farming Beneficiaries

    Directory of Open Access Journals (Sweden)

    A.V. Greena

    2016-05-01

    Full Text Available Precision Farming is one of the many advanced farming practices that make production more efficient by better resource management and reducing wastage. TN-IAMWARM is a world bank funded project aims to improve the farm productivity and income through better water management. The present study was carried out in Kambainallur sub basin of Dharmapuri district with 120 TN-IAMWARM beneficiaries as respondents. The result indicated that more than three fourth (76.67 % of the respondents had high level of knowledge on precision farming technologies which was made possible by the implementation of TN-IAMWARM project. The study further revealed that educational status, occupational status and exposure to agricultural messages had a positive and significant contribution to the knowledge level of the respondents at 0.01 level of probability whereas experience in precision farming and social participation had a positive and significant contribution at 0.05 level of probability.

  10. ArcticDEM Validation and Accuracy Assessment

    Science.gov (United States)

    Candela, S. G.; Howat, I.; Noh, M. J.; Porter, C. C.; Morin, P. J.

    2017-12-01

    ArcticDEM comprises a growing inventory Digital Elevation Models (DEMs) covering all land above 60°N. As of August, 2017, ArcticDEM had openly released 2-m resolution, individual DEM covering over 51 million km2, which includes areas of repeat coverage for change detection, as well as over 15 million km2 of 5-m resolution seamless mosaics. By the end of the project, over 80 million km2 of 2-m DEMs will be produced, averaging four repeats of the 20 million km2 Arctic landmass. ArcticDEM is produced from sub-meter resolution, stereoscopic imagery using open source software (SETSM) on the NCSA Blue Waters supercomputer. These DEMs have known biases of several meters due to errors in the sensor models generated from satellite positioning. These systematic errors are removed through three-dimensional registration to high-precision Lidar or other control datasets. ArcticDEM is registered to seasonally-subsetted ICESat elevations due its global coverage and high report accuracy ( 10 cm). The vertical accuracy of ArcticDEM is then obtained from the statistics of the fit to the ICESat point cloud, which averages -0.01 m ± 0.07 m. ICESat, however, has a relatively coarse measurement footprint ( 70 m) which may impact the precision of the registration. Further, the ICESat data predates the ArcticDEM imagery by a decade, so that temporal changes in the surface may also impact the registration. Finally, biases may exist between different the different sensors in the ArcticDEM constellation. Here we assess the accuracy of ArcticDEM and the ICESat registration through comparison to multiple high-resolution airborne lidar datasets that were acquired within one year of the imagery used in ArcticDEM. We find the ICESat dataset is performing as anticipated, introducing no systematic bias during the coregistration process, and reducing vertical errors to within the uncertainty of the airborne Lidars. Preliminary sensor comparisons show no significant difference post coregistration

  11. Sternal instability measured with radiostereometric analysis. A study of method feasibility, accuracy and precision

    DEFF Research Database (Denmark)

    Vestergaard, Rikke Falsig; Søballe, Kjeld; Hasenkam, John Michael

    2018-01-01

    BACKGROUND: A small, but unstable, saw-gap may hinder bone-bridging and induce development of painful sternal dehiscence. We propose the use of Radiostereometric Analysis (RSA) for evaluation of sternal instability and present a method validation. METHODS: Four bone analogs (phantoms) were sterno...... modality feasible for clinical evaluation of sternal stability in research. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02738437 , retrospectively registered.......BACKGROUND: A small, but unstable, saw-gap may hinder bone-bridging and induce development of painful sternal dehiscence. We propose the use of Radiostereometric Analysis (RSA) for evaluation of sternal instability and present a method validation. METHODS: Four bone analogs (phantoms) were...

  12. A 'same day' TSH radioimmunoassay kit with acceptable precision and accuracy

    International Nuclear Information System (INIS)

    Wood, W.G.; Muenchen Univ.

    1980-01-01

    A new 'same-day' TSH-RIA kit has been tested against an 'in-house' TSH-RIA, using incubation schemes of 4, 22 and 23 h. The kit standards were made up in human TSH-free serum and the method used a preincubation step and separation of bound and free antigen using a double antibody method. The correlation between the 'in-house' method and the kit was very good. The results in sera from TRH-test patients, and also from a recovery test with MRC 68/38 in human serum covering the range 0-50 mU/l were good. A comparison of the new kit was made with its precedessor which had protein based standards highlighted the need for standards in human TSH-free serum seen by the poor correlation (r = 0.619, n = 93). (orig.) [de

  13. Accuracy and precision of loss-free counting in γ-ray spectrometry

    International Nuclear Information System (INIS)

    Pomme, S.; Alzetta, J-P.; Uyttenhove, J.; Denecke, B.; Arana, G.; Robouch, P.

    1999-01-01

    The performance of a 'Loss-Free Counting' (LFC) method for pulse loss compensation is tested on two HPGe detectors; one with classical RC feedback preamplifier and another with Transistor Reset Preamplifier (TRP). Results are excellent on both, though extra fine-tuning precautions are required for the latter. Pulse loss by pileup is at the origin of an increased count variance in LFC spectra. A new formula for LFC uncertainty is presented and its validity demonstrated for a HPGe detector set-up

  14. Radiochromic film dosimetry. Considerations on precision and accuracy for EBT2 and EBT3 type films

    Energy Technology Data Exchange (ETDEWEB)

    Dreindl, Ralf [Medical Univ. of Vienna/Vienna General Hospital (Austria). Dept. of Radiooncology; EBG MedAustron GmbH, Wiener Neustadt (Austria); Georg, Dietmar; Stock, Markus [Medical Univ. of Vienna/Vienna General Hospital (Austria). Dept. of Radiooncology; Medical Univ. of Vienna (Austria). Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology

    2014-09-01

    Gafchromic {sup registered} EBT2 film is a widely used dosimetric tool for quality assurance in radiation therapy. In 2012 EBT3 was presented as a replacement for EBT2 films. The symmetric structure of EBT3 films to reduce face-up/down dependency as well as the inclusion of a matte film surface to frustrate Newton Ring artifacts present the most prominent improvements of EBT3 films. The aim of this study was to investigate the characteristics of EBT3 films, to benchmark the films against the known EBT2-features and to evaluate the dosimetric behavior over a time period greater than 6 months. All films were irradiated to clinical photon beams (6MV, 10MV and 18MV) on an Elekta Synergy Linac equipped with a Beam Modulator MLC in solid water phantom slabs. Film digitalization was done with a flatbed transparency scanner (Type Epson Expression 1680 Pro). MATLAB {sup registered} was used for further statistical calculations and image processing. The investigations on post-irradiation darkening, film orientation, film uniformity and energy dependency resulted in negligible differences between EBT2 and EBT3 film. A minimal improvement in face-up/down dependence was found for EBT3. The matte film surface of EBT3 films turned out to be a practical feature as Newton rings could be eliminated completely. Considering long-term behavior (> 6 months) a shift of the calibration curve for EBT2 and EBT3 films due to changes in the dynamic response of the active component was observed. In conclusion, the new EBT3 film yields comparable results to its predecessor EBT2. The general advantages of radiochromic film dosimeters are completed by high film homogeneity, low energy dependence for the observed energy range and a minimized face-up/down dependence. EBT2 dosimetry-protocols can also be used for EBT3 films, but the inclusion of periodical recalibration-interval (e.g. once a quarter) is recommended for protocols of both film generations. (orig.)

  15. Radiochromic film dosimetry: considerations on precision and accuracy for EBT2 and EBT3 type films.

    Science.gov (United States)

    Dreindl, Ralf; Georg, Dietmar; Stock, Markus

    2014-05-01

    Gafchromic® EBT2 film is a widely used dosimetric tool for quality assurance in radiation therapy. In 2012 EBT3 was presented as a replacement for EBT2 films. The symmetric structure of EBT3 films to reduce face-up/down dependency as well as the inclusion of a matte film surface to frustrate Newton Ring artifacts present the most prominent improvements of EBT3 films. The aim of this study was to investigate the characteristics of EBT3 films, to benchmark the films against the known EBT2-features and to evaluate the dosimetric behavior over a time period greater than 6 months. All films were irradiated to clinical photon beams (6 MV, 10 MV and 18 MV) on an Elekta Synergy Linac equipped with a Beam Modulator MLC in solid water phantom slabs. Film digitalization was done with a flatbed transparency scanner (Type Epson Expression 1680 Pro). MATLAB® was used for further statistical calculations and image processing. The investigations on post-irradiation darkening, film orientation, film uniformity and energy dependency resulted in negligible differences between EBT2 and EBT3 film. A minimal improvement in face-up/down dependence was found for EBT3. The matte film surface of EBT3 films turned out to be a practical feature as Newton rings could be eliminated completely. Considering long-term behavior (> 6 months) a shift of the calibration curve for EBT2 and EBT3 films due to changes in the dynamic response of the active component was observed. In conclusion, the new EBT3 film yields comparable results to its predecessor EBT2. The general advantages of radiochromic film dosimeters are completed by high film homogeneity, low energy dependence for the observed energy range and a minimized face-up/down dependence. EBT2 dosimetry-protocols can also be used for EBT3 films, but the inclusion of periodical recalibration-interval (e.g. once a quarter) is recommended for protocols of both film generations. Copyright © 2013. Published by Elsevier GmbH.

  16. Precision, accuracy and linearity of radiometer EML 105 whole blood metabolite biosensors.

    Science.gov (United States)

    Cobbaert, C; Morales, C; van Fessem, M; Kemperman, H

    1999-11-01

    The analytical performance of a new, whole blood glucose and lactate electrode system (EML 105 analyser. Radiometer Medical A/S. Copenhagen, Denmark) was evaluated. Between-day coefficients of variation were glucose and lactate, respectively. Recoveries of glucose were 100 +/- 10% using either aqueous or protein-based standards. Recoveries of lactate depended on the matrix, being underestimated in aqueous standards (approximately -10%) and 95-100% in standards containing 40 g/L albumin at lactate concentrations of 15 and 30 mmol/L. However, recoveries were high (up to 180%) at low lactate concentrations in protein-based standards. Carry-over, investigated according to National Clinical Chemistry Laboratory Standards EP10-T2, was negligible (alpha = 0.01). Glucose and lactate biosensors equipped with new membranes were linear up to 60 and 30 mmol/L, respectively. However, linearity fell upon daily use with increasing membrane lifetime. We conclude that the Radiometer metabolite biosensor results are reproducible and do not suffer from specimen-related carry-over. However, lactate recovery depends on the protein content and the lactate concentration.

  17. Radiochromic film dosimetry. Considerations on precision and accuracy for EBT2 and EBT3 type films

    International Nuclear Information System (INIS)

    Dreindl, Ralf; Georg, Dietmar; Stock, Markus; Medical Univ. of Vienna

    2014-01-01

    Gafchromic registered EBT2 film is a widely used dosimetric tool for quality assurance in radiation therapy. In 2012 EBT3 was presented as a replacement for EBT2 films. The symmetric structure of EBT3 films to reduce face-up/down dependency as well as the inclusion of a matte film surface to frustrate Newton Ring artifacts present the most prominent improvements of EBT3 films. The aim of this study was to investigate the characteristics of EBT3 films, to benchmark the films against the known EBT2-features and to evaluate the dosimetric behavior over a time period greater than 6 months. All films were irradiated to clinical photon beams (6MV, 10MV and 18MV) on an Elekta Synergy Linac equipped with a Beam Modulator MLC in solid water phantom slabs. Film digitalization was done with a flatbed transparency scanner (Type Epson Expression 1680 Pro). MATLAB registered was used for further statistical calculations and image processing. The investigations on post-irradiation darkening, film orientation, film uniformity and energy dependency resulted in negligible differences between EBT2 and EBT3 film. A minimal improvement in face-up/down dependence was found for EBT3. The matte film surface of EBT3 films turned out to be a practical feature as Newton rings could be eliminated completely. Considering long-term behavior (> 6 months) a shift of the calibration curve for EBT2 and EBT3 films due to changes in the dynamic response of the active component was observed. In conclusion, the new EBT3 film yields comparable results to its predecessor EBT2. The general advantages of radiochromic film dosimeters are completed by high film homogeneity, low energy dependence for the observed energy range and a minimized face-up/down dependence. EBT2 dosimetry-protocols can also be used for EBT3 films, but the inclusion of periodical recalibration-interval (e.g. once a quarter) is recommended for protocols of both film generations. (orig.)

  18. High precision pulsar timing and spin frequency second derivatives

    Science.gov (United States)

    Liu, X. J.; Bassa, C. G.; Stappers, B. W.

    2018-05-01

    We investigate the impact of intrinsic, kinematic and gravitational effects on high precision pulsar timing. We present an analytical derivation and a numerical computation of the impact of these effects on the first and second derivative of the pulsar spin frequency. In addition, in the presence of white noise, we derive an expression to determine the expected measurement uncertainty of a second derivative of the spin frequency for a given timing precision, observing cadence and timing baseline and find that it strongly depends on the latter (∝t-7/2). We show that for pulsars with significant proper motion, the spin frequency second derivative is dominated by a term dependent on the radial velocity of the pulsar. Considering the data sets from three Pulsar Timing Arrays, we find that for PSR J0437-4715 a detectable spin frequency second derivative will be present if the absolute value of the radial velocity exceeds 33 km s-1. Similarly, at the current timing precision and cadence, continued timing observations of PSR J1909-3744 for about another eleven years, will allow the measurement of its frequency second derivative and determine the radial velocity with an accuracy better than 14 km s-1. With the ever increasing timing precision and observing baselines, the impact of the, largely unknown, radial velocities of pulsars on high precision pulsar timing can not be neglected.

  19. Methods Research about Accuracy Loss Tracing of Dynamic Measurement System Based on WNN

    International Nuclear Information System (INIS)

    Lin, S-W; Fei, Y T; Jiang, M L; Tsai, C-Y; Cheng Hsinyu

    2006-01-01

    The paper presents a method of achieving accuracy loss of the dynamic measurement system according to change of errors on different period of the system. WNN, used to trace the accuracy loss of dynamic measurement system, traces the total precision loss during a certain period to every part of the system, and the accuracy loss of every part can be get, so retaining the accuracy and optimum design of the system is possible. Take tracing the accuracy loss of a simulated system for an example to testify the method

  20. High current high accuracy IGBT pulse generator

    International Nuclear Information System (INIS)

    Nesterov, V.V.; Donaldson, A.R.

    1995-05-01

    A solid state pulse generator capable of delivering high current triangular or trapezoidal pulses into an inductive load has been developed at SLAC. Energy stored in a capacitor bank of the pulse generator is switched to the load through a pair of insulated gate bipolar transistors (IGBT). The circuit can then recover the remaining energy and transfer it back to the capacitor bank without reversing the capacitor voltage. A third IGBT device is employed to control the initial charge to the capacitor bank, a command charging technique, and to compensate for pulse to pulse power losses. The rack mounted pulse generator contains a 525 μF capacitor bank. It can deliver 500 A at 900V into inductive loads up to 3 mH. The current amplitude and discharge time are controlled to 0.02% accuracy by a precision controller through the SLAC central computer system. This pulse generator drives a series pair of extraction dipoles

  1. Test Expectancy Affects Metacomprehension Accuracy

    Science.gov (United States)

    Thiede, Keith W.; Wiley, Jennifer; Griffin, Thomas D.

    2011-01-01

    Background: Theory suggests that the accuracy of metacognitive monitoring is affected by the cues used to judge learning. Researchers have improved monitoring accuracy by directing attention to more appropriate cues; however, this is the first study to more directly point students to more appropriate cues using instructions regarding tests and…

  2. About the problems and perspectives of making precision compressor blades

    Directory of Open Access Journals (Sweden)

    V. E. Galiev

    2014-01-01

    Full Text Available The problems of manufacturing blades with high precision profile geometry are considered in the article. The variant of the technology under development rules out the use of mechanical processing methods for blades airfoil. The article consists of an introduction and six small sections.The introduction sets out the requirements for modern aircraft engines, makes a list of problems arisen in the process of their manufacturing, and marks the relevance of the work.The first section analyzes the existing technology of precision blades. There is an illustration reflecting the stages of the process. Their advantages and disadvantages are marked.The second section provides an illustration, which shows the system-based blades used in the manufacturing process and a model of the work piece using the technology being developed. An analysis of each basing scheme is presented.In the third section we list the existing control methods of geometrical parameters of blades airfoil and present the measurement error data of devices. The special attention is paid to the impossibility to control the accuracy of geometrical parameters of precision blades.The fourth section presents the advantages of the electrochemical machining method with a consistent vibration of tool-electrode and with feeding the pulses of technology current over the traditional method. The article presents data accuracy and surface roughness of the blades airfoil reached owing to precision electrochemical machining. It illustrates machines that implement the given method of processing and components manufactured on them.The fifth section describes the steps of the developed process with justification for the use of the proposed operations.Based on the analysis, the author argues that the application of the proposed process to manufacture the precision compressor blades ensures producing the items that meet the requirements of the drawing.

  3. Accuracy and detection limits for bioassay measurements in radiation protection. Statistical considerations

    International Nuclear Information System (INIS)

    Brodsky, A.

    1986-04-01

    This report provides statistical concepts and formulas for defining minimum detectable amount (MDA), bias and precision of sample analytical measurements of radioactivity for radiobioassay purposes. The defined statistical quantities and accuracy criteria were developed for use in standard performance criteria for radiobioassay, but are also useful in intralaboratory quality assurance programs. This report also includes a literature review and analysis of accuracy needs and accuracy recommendations of national and international scientific organizations for radiation or radioactivity measurements used for radiation protection purposes. Computer programs are also included for calculating the probabilities of passing or failing multiple analytical tests for different acceptable ranges of bias and precision

  4. Improvement of the decision efficiency of the accuracy profile by means of a desirability function for analytical methods validation. Application to a diacetyl-monoxime colorimetric assay used for the determination of urea in transdermal iontophoretic extracts.

    Science.gov (United States)

    Rozet, E; Wascotte, V; Lecouturier, N; Préat, V; Dewé, W; Boulanger, B; Hubert, Ph

    2007-05-22

    Validation of analytical methods is a widely used and regulated step for each analytical method. However, the classical approaches to demonstrate the ability to quantify of a method do not necessarily fulfill this objective. For this reason an innovative methodology was recently introduced by using the tolerance interval and accuracy profile, which guarantee that a pre-defined proportion of future measurements obtained with the method will be included within the acceptance limits. Accuracy profile is an effective decision tool to assess the validity of analytical methods. The methodology to build such a profile is detailed here. However, as for any visual tool it has a part of subjectivity. It was then necessary to make the decision process objective in order to quantify the degree of adequacy of an accuracy profile and to allow a thorough comparison between such profiles. To achieve this, we developed a global desirability index based on the three most important validation criteria: the trueness, the precision and the range. The global index allows the classification of the different accuracy profiles obtained according to their respective response functions. A diacetyl-monoxime colorimetric assay for the determination of urea in transdermal iontophoretic extracts was used to illustrate these improvements.

  5. Precision kaon and hadron physics with KLOE

    International Nuclear Information System (INIS)

    Bossi, F.; De Lucia, E.; Lee-Franzini, J.; Miscetti, S.; Palutan, M.

    2008-01-01

    We describe the KLOE detector at DAΦNE, the Frascati φ, and its physics program. We begin with a brief description of the detector design and operation. Kaon physics is a major topic of investigation with KLOE thanks in part to the unique availability of pure K S , K L , K ± beams at a φ. We have measured all significant branching ratios of all kaon species, the K L and K ± lifetimes and the K → π form factor's t dependence. From the measurements we verify the validity of Cabibbo unitarity and lepton universality. We have studied properties of light scalar and pseudoscalar mesons with unprecedented accuracy. We have measured the e + e - → π + π - cross-section necessary for computing the major part of the hadronic contribution to the muon anomaly. The methods employed in all the above measurements as well as the φ leptonic width, precision mass measurements and searches for forbidden or extremely rare decays of kaons and η-mesons arc described. The impact of our results on flavor and hadron physics to date, as well as an outlook for further improvement in the near future, are discussed

  6. LHC Power Converters: A Precision Game

    CERN Multimedia

    2001-01-01

    The LHC test-bed, String 2, is close to commissioning and one important element to get a first chance to prove what it can do is the power converter system. In String 2 there are 16 converters, in the full LHC there will be almost 1800. This article takes a look at what is so special about the power converters for the LHC. The 13 000 Amps power converters with the watercooled cables going to the String 2 feedboxes. The LHC's superconducting magnets will be the pinnacle of high technology. But to work, they'll need the help of high-precision power converters to supply them with extremely stable DC current. Perfection will be the name of the game, with an accuracy of just 1-2 parts per million (ppm) required. LEP, for the sake of comparison, could live with 10-20 ppm. The LHC's power converters will be very different from those of LEP or the SPS since the new accelerator's magnets are mostly superconducting. That means that they require much higher currents at a lower voltage since superconductors have no re...

  7. On the Numerical Accuracy of Spreadsheets

    Directory of Open Access Journals (Sweden)

    Alejandro C. Frery

    2010-10-01

    Full Text Available This paper discusses the numerical precision of five spreadsheets (Calc, Excel, Gnumeric, NeoOffice and Oleo running on two hardware platforms (i386 and amd64 and on three operating systems (Windows Vista, Ubuntu Intrepid and Mac OS Leopard. The methodology consists of checking the number of correct significant digits returned by each spreadsheet when computing the sample mean, standard deviation, first-order autocorrelation, F statistic in ANOVA tests, linear and nonlinear regression and distribution functions. A discussion about the algorithms for pseudorandom number generation provided by these platforms is also conducted. We conclude that there is no safe choice among the spreadsheets here assessed: they all fail in nonlinear regression and they are not suited for Monte Carlo experiments.

  8. Why precision medicine is not the best route to a healthier world.

    Science.gov (United States)

    Rey-López, Juan Pablo; Sá, Thiago Herick de; Rezende, Leandro Fórnias Machado de

    2018-02-05

    Precision medicine has been announced as a new health revolution. The term precision implies more accuracy in healthcare and prevention of diseases, which could yield substantial cost savings. However, scientific debate about precision medicine is needed to avoid wasting economic resources and hype. In this commentary, we express the reasons why precision medicine cannot be a health revolution for population health. Advocates of precision medicine neglect the limitations of individual-centred, high-risk strategies (reduced population health impact) and the current crisis of evidence-based medicine. Overrated "precision medicine" promises may be serving vested interests, by dictating priorities in the research agenda and justifying the exorbitant healthcare expenditure in our finance-based medicine. If societies aspire to address strong risk factors for non-communicable diseases (such as air pollution, smoking, poor diets, or physical inactivity), they need less medicine and more investment in population prevention strategies.

  9. Flexible single-layer ionic organic-inorganic frameworks towards precise nano-size separation

    Science.gov (United States)

    Yue, Liang; Wang, Shan; Zhou, Ding; Zhang, Hao; Li, Bao; Wu, Lixin

    2016-02-01

    Consecutive two-dimensional frameworks comprised of molecular or cluster building blocks in large area represent ideal candidates for membranes sieving molecules and nano-objects, but challenges still remain in methodology and practical preparation. Here we exploit a new strategy to build soft single-layer ionic organic-inorganic frameworks via electrostatic interaction without preferential binding direction in water. Upon consideration of steric effect and additional interaction, polyanionic clusters as connection nodes and cationic pseudorotaxanes acting as bridging monomers connect with each other to form a single-layer ionic self-assembled framework with 1.4 nm layer thickness. Such soft supramolecular polymer frameworks possess uniform and adjustable ortho-tetragonal nanoporous structure in pore size of 3.4-4.1 nm and exhibit greatly convenient solution processability. The stable membranes maintaining uniform porous structure demonstrate precisely size-selective separation of semiconductor quantum dots within 0.1 nm of accuracy and may hold promise for practical applications in selective transport, molecular separation and dialysis systems.

  10. Constraining supersymmetry with precision data

    International Nuclear Information System (INIS)

    Pierce, D.M.; Erler, J.

    1997-01-01

    We discuss the results of a global fit to precision data in supersymmetric models. We consider both gravity- and gauge-mediated models. As the superpartner spectrum becomes light, the global fit to the data typically results in larger values of χ 2 . We indicate the regions of parameter space which are excluded by the data. We discuss the additional effect of the B(B→X s γ) measurement. Our analysis excludes chargino masses below M Z in the simplest gauge-mediated model with μ>0, with stronger constraints for larger values of tanβ. copyright 1997 American Institute of Physics

  11. High precision Standard Model Physics

    International Nuclear Information System (INIS)

    Magnin, J.

    2009-01-01

    The main goal of the LHCb experiment, one of the four large experiments of the Large Hadron Collider, is to try to give answers to the question of why Nature prefers matter over antimatter? This will be done by studying the decay of b quarks and their antimatter partners, b-bar, which will be produced by billions in 14 TeV p-p collisions by the LHC. In addition, as 'beauty' particles mainly decay in charm particles, an interesting program of charm physics will be carried on, allowing to measure quantities as for instance the D 0 -D-bar 0 mixing, with incredible precision.

  12. Electroweak precision measurements in CMS

    CERN Document Server

    Dordevic, Milos

    2017-01-01

    An overview of recent results on electroweak precision measurements from the CMS Collaboration is presented. Studies of the weak boson differential transverse momentum spectra, Z boson angular coefficients, forward-backward asymmetry of Drell-Yan lepton pairs and charge asymmetry of W boson production are made in comparison to the state-of-the-art Monte Carlo generators and theoretical predictions. The results show a good agreement with the Standard Model. As a proof of principle for future W mass measurements, a W-like analysis of the Z boson mass is performed.

  13. Precision proton spectrometers for CMS

    CERN Document Server

    Albrow, Michael

    2013-01-01

    We plan to add high precision tracking- and timing-detectors at z = +/- 240 m to CMS to study exclusive processes p + p -- p + X + p at high luminosity. This enables the LHC to be used as a tagged photon-photon collider, with X = l+l- and W+W-, and as a "tagged" gluon-gluon collider (with a spectator gluon) for QCD studies with jets. A second stage at z = 240 m would allow observations of exclusive Higgs boson production.

  14. Precise Analysis of String Expressions

    DEFF Research Database (Denmark)

    Christensen, Aske Simon; Møller, Anders; Schwartzbach, Michael Ignatieff

    2003-01-01

    We perform static analysis of Java programs to answer a simple question: which values may occur as results of string expressions? The answers are summarized for each expression by a regular language that is guaranteed to contain all possible values. We present several applications of this analysis...... are automatically produced. We present extensive benchmarks demonstrating that the analysis is efficient and produces results of useful precision......., including statically checking the syntax of dynamically generated expressions, such as SQL queries. Our analysis constructs flow graphs from class files and generates a context-free grammar with a nonterminal for each string expression. The language of this grammar is then widened into a regular language...

  15. The Many Faces of Precision

    Directory of Open Access Journals (Sweden)

    Andy eClark

    2013-05-01

    Full Text Available An appreciation of the many roles of ‘precision-weighting’ (upping the gain on select populations of prediction error units opens the door to better accounts of planning and ‘offline simulation’, makes suggestive contact with large bodies of work on embodied and situated cognition, and offers new perspectives on the ‘active brain’. Combined with the complex affordances of language and culture, and operating against the essential backdrop of a variety of more biologically basic ploys and stratagems, the result is a maximally context-sensitive, restless, constantly self-reconfiguring architecture.

  16. Thin films for precision optics

    International Nuclear Information System (INIS)

    Araujo, J.F.; Maurici, N.; Castro, J.C. de

    1983-01-01

    The technology of producing dielectric and/or metallic thin films for high precision optical components is discussed. Computer programs were developed in order to calculate and register, graphically, reflectance and transmittance spectra of multi-layer films. The technology of vacuum evaporation of several materials was implemented in our thin-films laboratory; various films for optics were then developed. The possibility of first calculate film characteristics and then produce the film is of great advantage since it reduces the time required to produce a new type of film and also reduces the cost of the project. (C.L.B.) [pt

  17. EVALUATING THE ACCURACY OF DEM GENERATION ALGORITHMS FROM UAV IMAGERY

    Directory of Open Access Journals (Sweden)

    J. J. Ruiz

    2013-08-01

    Full Text Available In this work we evaluated how the use of different positioning systems affects the accuracy of Digital Elevation Models (DEMs generated from aerial imagery obtained with Unmanned Aerial Vehicles (UAVs. In this domain, state-of-the-art DEM generation algorithms suffer from typical errors obtained by GPS/INS devices in the position measurements associated with each picture obtained. The deviations from these measurements to real world positions are about meters. The experiments have been carried out using a small quadrotor in the indoor testbed at the Center for Advanced Aerospace Technologies (CATEC. This testbed houses a system that is able to track small markers mounted on the UAV and along the scenario with millimeter precision. This provides very precise position measurements, to which we can add random noise to simulate errors in different GPS receivers. The results showed that final DEM accuracy clearly depends on the positioning information.

  18. Precision enhancement of pavement roughness localization with connected vehicles

    International Nuclear Information System (INIS)

    Bridgelall, R; Huang, Y; Zhang, Z; Deng, F

    2016-01-01

    Transportation agencies rely on the accurate localization and reporting of roadway anomalies that could pose serious hazards to the traveling public. However, the cost and technical limitations of present methods prevent their scaling to all roadways. Connected vehicles with on-board accelerometers and conventional geospatial position receivers offer an attractive alternative because of their potential to monitor all roadways in real-time. The conventional global positioning system is ubiquitous and essentially free to use but it produces impractically large position errors. This study evaluated the improvement in precision achievable by augmenting the conventional geo-fence system with a standard speed bump or an existing anomaly at a pre-determined position to establish a reference inertial marker. The speed sensor subsequently generates position tags for the remaining inertial samples by computing their path distances relative to the reference position. The error model and a case study using smartphones to emulate connected vehicles revealed that the precision in localization improves from tens of metres to sub-centimetre levels, and the accuracy of measuring localized roughness more than doubles. The research results demonstrate that transportation agencies will benefit from using the connected vehicle method to achieve precision and accuracy levels that are comparable to existing laser-based inertial profilers. (paper)

  19. Accuracy of colonoscopy in localizing colonic cancer.

    Science.gov (United States)

    Stanciu, C; Trifan, Anca; Khder, Saad Alla

    2007-01-01

    It is important to establish the precise localization of colonic cancer preoperatively; while colonoscopy is regarded as the diagnostic gold standard for colorectal cancer, its ability to localize the tumor is less reliable. To define the accuracy of colonoscopy in identifying the location of colonic cancer. All of the patients who had a colorectal cancer diagnosed by colonoscopy at the Institute of Gastroenterology and Hepatology, Iaşi and subsequently received a surgical intervention at three teaching hospitals in Iaşi, between January 2001 and December 2005, were included in this study. Endoscopic records and operative notes were carefully reviewed, and tumor localization was recorded. There were 161 patients (89 men, 72 women, aged 61.3 +/- 12.8 years) who underwent conventional surgery for colon cancer detected by colonoscopy during the study period. Twenty-two patients (13.66%) had erroneous colonoscopic localization of the tumors. The overall accuracy of preoperative colonoscopic localization was 87.58%. Colonoscopy is an accurate, reliable method for locating colon cancer, although additional techniques (i.e., endoscopic tattooing) should be performed at least for small lesions.

  20. Accuracy requirements in radiotherapy treatment planning

    International Nuclear Information System (INIS)

    Buzdar, S. A.; Afzal, M.; Nazir, A.; Gadhi, M. A.

    2013-01-01

    Radiation therapy attempts to deliver ionizing radiation to the tumour and can improve the survival chances and/or quality of life of patients. There are chances of errors and uncertainties in the entire process of radiotherapy that may affect the accuracy and precision of treatment management and decrease degree of conformation. All expected inaccuracies, like radiation dose determination, volume calculation, complete evaluation of the full extent of the tumour, biological behaviour of specific tumour types, organ motion during radiotherapy, imaging, biological/molecular uncertainties, sub-clinical diseases, microscopic spread of the disease, uncertainty in normal tissue responses and radiation morbidity need sound appreciation. Conformity can be increased by reduction of such inaccuracies. With the yearly increase in computing speed and advancement in other technologies the future will provide the opportunity to optimize a greater number of variables and reduce the errors in the treatment planning process. In multi-disciplined task of radiotherapy, efforts are needed to overcome the errors and uncertainty, not only by the physicists but also by radiologists, pathologists and oncologists to reduce molecular and biological uncertainties. The radiation therapy physics is advancing towards an optimal goal that is definitely to improve accuracy where necessary and to reduce uncertainty where possible. (author)

  1. An experimental methodology for a fuzzy set preference model

    Science.gov (United States)

    Turksen, I. B.; Willson, Ian A.

    1992-01-01

    A flexible fuzzy set preference model first requires approximate methodologies for implementation. Fuzzy sets must be defined for each individual consumer using computer software, requiring a minimum of time and expertise on the part of the consumer. The amount of information needed in defining sets must also be established. The model itself must adapt fully to the subject's choice of attributes (vague or precise), attribute levels, and importance weights. The resulting individual-level model should be fully adapted to each consumer. The methodologies needed to develop this model will be equally useful in a new generation of intelligent systems which interact with ordinary consumers, controlling electronic devices through fuzzy expert systems or making recommendations based on a variety of inputs. The power of personal computers and their acceptance by consumers has yet to be fully utilized to create interactive knowledge systems that fully adapt their function to the user. Understanding individual consumer preferences is critical to the design of new products and the estimation of demand (market share) for existing products, which in turn is an input to management systems concerned with production and distribution. The question of what to make, for whom to make it and how much to make requires an understanding of the customer's preferences and the trade-offs that exist between alternatives. Conjoint analysis is a widely used methodology which de-composes an overall preference for an object into a combination of preferences for its constituent parts (attributes such as taste and price), which are combined using an appropriate combination function. Preferences are often expressed using linguistic terms which cannot be represented in conjoint models. Current models are also not implemented an individual level, making it difficult to reach meaningful conclusions about the cause of an individual's behavior from an aggregate model. The combination of complex aggregate

  2. Comparison of results between different precision MAFIA codes

    International Nuclear Information System (INIS)

    Farkas, D.; Tice, B.

    1990-01-01

    In order to satisfy the inquiries of the Mafia Code users at SLAC, an evaluation of these codes was done. This consisted of running a cavity with known solutions. This study considered only the time independent solutions. No wake-field calculations were tried. The two machines involved were the NMFECC Cray (e-machine) at LLNL and the IBM/3081 at SLAC. The primary difference between the implementation of the codes on these machines is that the Cray has 64-bit accuracy while the IBM version has 32-bit accuracy. Unfortunately this study is incomplete as the Post-processor (P3) could not be made to work properly on the SLAC machine. This meant that no q's were calculated and no field patterns were generated. A certain amount of guessing had to be done when constructing the comparison tables. This problem aside, the probable conclusions that may be drawn are: (1) thirty-two bit precision is adequate for frequency determination; (2) sixty-four bit precision is desirable for field determination. This conclusion is deduced from the accuracy statistics. The cavity selected for study was a rectangular one with the dimensions (4,3,5) in centimeters. Only half of this cavity was used (2,3,5) with the x dimension being the one that was halved. The boundary conditions (B.C.) on the plane of symmetry were varied between Neumann and Dirichlet so as to cover all possible modes. Ten (10) modes were ran for each boundary condition

  3. K0-INAA method accuracy using Zn as comparator

    International Nuclear Information System (INIS)

    Bedregal, P.; Mendoza, P.; Ubillus, M.; Montoya, E.

    2010-01-01

    An evaluation of the accuracy in the application of the k 0 -INAA method using Zn foil as comparator is presented. A good agreement was found in the precision within analysts and between them, as well as in the assessment of trueness for most elements. The determination of important experimental parameters like gamma peak counting efficiency, γ-γ true coincidence, comparator preparation and quality assurance/quality control is also described and discussed.

  4. Precision luminosity measurements at LHCb

    CERN Document Server

    Aaij, Roel; Adinolfi, Marco; Affolder, Anthony; Ajaltouni, Ziad; Akar, Simon; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio Augusto; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Anderson, Jonathan; Andreassen, Rolf; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Aquines Gutierrez, Osvaldo; Archilli, Flavio; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Auriemma, Giulio; Baalouch, Marouen; Bachmann, Sebastian; Back, John; Badalov, Alexey; Baesso, Clarissa; Baldini, Wander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Batozskaya, Varvara; Battista, Vincenzo; Bay, Aurelio; Beaucourt, Leo; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Belogurov, Sergey; Belous, Konstantin; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Benton, Jack; Berezhnoy, Alexander; Bernet, Roland; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bien, Alexander; Bifani, Simone; Bird, Thomas; Bizzeti, Andrea; Bjørnstad, Pål Marius; Blake, Thomas; Blanc, Frédéric; Blouw, Johan; Blusk, Steven; Bocci, Valerio; Bondar, Alexander; Bondar, Nikolay; Bonivento, Walter; Borghi, Silvia; Borgia, Alessandra; Borsato, Martino; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Brambach, Tobias; Bressieux, Joël; Brett, David; Britsch, Markward; Britton, Thomas; Brodzicka, Jolanta; Brook, Nicholas; Brown, Henry; Bursche, Albert; Buytaert, Jan; Cadeddu, Sandro; Calabrese, Roberto; Calvi, Marta; Calvo Gomez, Miriam; Campana, Pierluigi; Campora Perez, Daniel; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casse, Gianluigi; Cassina, Lorenzo; Castillo Garcia, Lucia; Cattaneo, Marco; Cauet, Christophe; Cenci, Riccardo; Charles, Matthew; Charpentier, Philippe; Chefdeville, Maximilien; Chen, Shanzhen; Cheung, Shu-Faye; Chiapolini, Nicola; Chrzaszcz, Marcin; Ciba, Krzystof; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coco, Victor; Cogan, Julien; Cogneras, Eric; Cojocariu, Lucian; Collazuol, Gianmaria; Collins, Paula; Comerma-Montells, Albert; Contu, Andrea; Cook, Andrew; Coombes, Matthew; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Counts, Ian; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Cruz Torres, Melissa Maria; Cunliffe, Samuel; Currie, Robert; D'Ambrosio, Carmelo; Dalseno, Jeremy; David, Pascal; David, Pieter; Davis, Adam; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Silva, Weeraddana; De Simone, Patrizia; Dean, Cameron Thomas; Decamp, Daniel; Deckenhoff, Mirko; Del Buono, Luigi; Déléage, Nicolas; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Di Canto, Angelo; Dijkstra, Hans; Donleavy, Stephanie; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Dossett, David; Dovbnya, Anatoliy; Dreimanis, Karlis; Dujany, Giulio; Dupertuis, Frederic; Durante, Paolo; Dzhelyadin, Rustem; Dziurda, Agnieszka; Dzyuba, Alexey; Easo, Sajan; Egede, Ulrik; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; El Rifai, Ibrahim; Elsasser, Christian; Ely, Scott; Esen, Sevda; Evans, Hannah Mary; Evans, Timothy; Falabella, Antonio; Färber, Christian; Farinelli, Chiara; Farley, Nathanael; Farry, Stephen; Fay, Robert; Ferguson, Dianne; Fernandez Albor, Victor; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fiore, Marco; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fol, Philip; Fontana, Marianna; Fontanelli, Flavio; Forty, Roger; Francisco, Oscar; Frank, Markus; Frei, Christoph; Frosini, Maddalena; Fu, Jinlin; Furfaro, Emiliano; Gallas Torreira, Abraham; Galli, Domenico; Gallorini, Stefano; Gambetta, Silvia; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; García Pardiñas, Julián; Garofoli, Justin; Garra Tico, Jordi; Garrido, Lluis; Gascon, David; Gaspar, Clara; Gauld, Rhorry; Gavardi, Laura; Geraci, Angelo; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianelle, Alessio; Gianì, Sebastiana; Gibson, Valerie; Giubega, Lavinia-Helena; Gligorov, V.V.; Göbel, Carla; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gotti, Claudio; Grabalosa Gándara, Marc; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graziani, Giacomo; Grecu, Alexandru; Greening, Edward; Gregson, Sam; Griffith, Peter; Grillo, Lucia; Grünberg, Oliver; Gui, Bin; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hall, Samuel; Hamilton, Brian; Hampson, Thomas; Han, Xiaoxue; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Harrison, Jonathan; He, Jibo; Head, Timothy; Heijne, Veerle; Hennessy, Karol; Henrard, Pierre; Henry, Louis; Hernando Morata, Jose Angel; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adlène; Hill, Donal; Hoballah, Mostafa; Hombach, Christoph; Hulsbergen, Wouter; Hunt, Philip; Hussain, Nazim; Hutchcroft, David; Hynds, Daniel; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jaeger, Andreas; Jalocha, Pawel; Jans, Eddy; Jaton, Pierre; Jawahery, Abolhassan; Jing, Fanfan; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kandybei, Sergii; Kanso, Walaa; Karacson, Matthias; Karbach, Moritz; Karodia, Sarah; Kelsey, Matthew; Kenyon, Ian; Ketel, Tjeerd; Khanji, Basem; Khurewathanakul, Chitsanu; Klaver, Suzanne; Klimaszewski, Konrad; Kochebina, Olga; Kolpin, Michael; Komarov, Ilya; Koopman, Rose; Koppenburg, Patrick; Korolev, Mikhail; Kozlinskiy, Alexandr; Kravchuk, Leonid; Kreplin, Katharina; Kreps, Michal; Krocker, Georg; Krokovny, Pavel; Kruse, Florian; Kucewicz, Wojciech; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kurek, Krzysztof; Kvaratskheliya, Tengiz; La Thi, Viet Nga; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lambert, Dean; Lambert, Robert W; Lanfranchi, Gaia; Langenbruch, Christoph; Langhans, Benedikt; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; van Leerdam, Jeroen; Lees, Jean-Pierre; Lefèvre, Regis; Leflat, Alexander; Lefrançois, Jacques; Leo, Sabato; Leroy, Olivier; Lesiak, Tadeusz; Leverington, Blake; Li, Yiming; Likhomanenko, Tatiana; Liles, Myfanwy; Lindner, Rolf; Linn, Christian; Lionetto, Federica; Liu, Bo; Lohn, Stefan; Longstaff, Iain; Lopes, Jose; Lopez-March, Neus; Lowdon, Peter; Lu, Haiting; Lucchesi, Donatella; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Machefert, Frederic; Machikhiliyan, Irina V; Maciuc, Florin; Maev, Oleg; Malde, Sneha; Malinin, Alexander; Manca, Giulia; Mancinelli, Giampiero; Mapelli, Alessandro; Maratas, Jan; Marchand, Jean François; Marconi, Umberto; Marin Benito, Carla; Marino, Pietro; Märki, Raphael; Marks, Jörg; Martellotti, Giuseppe; Martens, Aurelien; Martín Sánchez, Alexandra; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Martins Tostes, Danielle; Massafferri, André; Matev, Rosen; Mathe, Zoltan; Matteuzzi, Clara; Maurin, Brice; Mazurov, Alexander; McCann, Michael; McCarthy, James; McNab, Andrew; McNulty, Ronan; McSkelly, Ben; Meadows, Brian; Meier, Frank; Meissner, Marco; Merk, Marcel; Milanes, Diego Alejandro; Minard, Marie-Noelle; Moggi, Niccolò; Molina Rodriguez, Josue; Monteil, Stephane; Morandin, Mauro; Morawski, Piotr; Mordà, Alessandro; Morello, Michael Joseph; Moron, Jakub; Morris, Adam Benjamin; Mountain, Raymond; Muheim, Franz; Müller, Katharina; Mussini, Manuel; Muster, Bastien; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Anh Duc; Nguyen, Thi-Dung; Nguyen-Mau, Chung; Nicol, Michelle; Niess, Valentin; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Novoselov, Alexey; O'Hanlon, Daniel Patrick; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Oggero, Serena; Ogilvy, Stephen; Okhrimenko, Oleksandr; Oldeman, Rudolf; Onderwater, Gerco; Orlandea, Marius; Otalora Goicochea, Juan Martin; Owen, Patrick; Oyanguren, Maria Arantza; Pal, Bilas Kanti; Palano, Antimo; Palombo, Fernando; Palutan, Matteo; Panman, Jacob; Papanestis, Antonios; Pappagallo, Marco; Pappalardo, Luciano; Parkes, Christopher; Parkinson, Christopher John; Passaleva, Giovanni; Patel, Girish; Patel, Mitesh; Patrignani, Claudia; Pearce, Alex; Pellegrino, Antonio; Pepe Altarelli, Monica; Perazzini, Stefano; Perret, Pascal; Perrin-Terrin, Mathieu; Pescatore, Luca; Pesen, Erhan; Pessina, Gianluigi; Petridis, Konstantin; Petrolini, Alessandro; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pilař, Tomas; Pinci, Davide; Pistone, Alessandro; Playfer, Stephen; Plo Casasus, Maximo; Polci, Francesco; Poluektov, Anton; Polycarpo, Erica; Popov, Alexander; Popov, Dmitry; Popovici, Bogdan; Potterat, Cédric; Price, Eugenia; Price, Joseph David; Prisciandaro, Jessica; Pritchard, Adrian; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Punzi, Giovanni; Qian, Wenbin; Rachwal, Bartolomiej; Rademacker, Jonas; Rakotomiaramanana, Barinjaka; Rama, Matteo; Rangel, Murilo; Raniuk, Iurii; Rauschmayr, Nathalie; Raven, Gerhard; Redi, Federico; Reichert, Stefanie; Reid, Matthew; dos Reis, Alberto; Ricciardi, Stefania; Richards, Sophie; Rihl, Mariana; Rinnert, Kurt; Rives Molina, Vincente; Robbe, Patrick; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Perez, Pablo; Roiser, Stefan; Romanovsky, Vladimir; Romero Vidal, Antonio; Rotondo, Marcello; Rouvinet, Julien; Ruf, Thomas; Ruiz, Hugo; Ruiz Valls, Pablo; Saborido Silva, Juan Jose; Sagidova, Naylya; Sail, Paul; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santovetti, Emanuele; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Saunders, Daniel Martin; Savrina, Darya; Schiller, Manuel; Schindler, Heinrich; Schlupp, Maximilian; Schmelling, Michael; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schubiger, Maxime; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Semennikov, Alexander; Sepp, Indrek; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shapoval, Illya; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Shires, Alexander; Silva Coutinho, Rafael; Simi, Gabriele; Sirendi, Marek; Skidmore, Nicola; Skwarnicki, Tomasz; Smith, Anthony; Smith, Edmund; Smith, Eluned; Smith, Jackson; Smith, Mark; Snoek, Hella; Sokoloff, Michael; Soler, Paul; Soomro, Fatima; Souza, Daniel; Souza De Paula, Bruno; Spaan, Bernhard; Sparkes, Ailsa; Spradlin, Patrick; Sridharan, Srikanth; Stagni, Federico; Stahl, Marian; Stahl, Sascha; Steinkamp, Olaf; Stenyakin, Oleg; Stevenson, Scott; Stoica, Sabin; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Straticiuc, Mihai; Straumann, Ulrich; Stroili, Roberto; Subbiah, Vijay Kartik; Sun, Liang; Sutcliffe, William; Swientek, Krzysztof; Swientek, Stefan; Syropoulos, Vasileios; Szczekowski, Marek; Szczypka, Paul; Szumlak, Tomasz; T'Jampens, Stephane; Teklishyn, Maksym; Tellarini, Giulia; Teubert, Frederic; Thomas, Christopher; Thomas, Eric; van Tilburg, Jeroen; Tisserand, Vincent; Tobin, Mark; Tolk, Siim; Tomassetti, Luca; Tonelli, Diego; Topp-Joergensen, Stig; Torr, Nicholas; Tournefier, Edwige; Tourneur, Stephane; Tran, Minh Tâm; Tresch, Marco; Trisovic, Ana; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tuning, Niels; Ubeda Garcia, Mario; Ukleja, Artur; Ustyuzhanin, Andrey; Uwer, Ulrich; Vacca, Claudia; Vagnoni, Vincenzo; Valenti, Giovanni; Vallier, Alexis; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vázquez Sierra, Carlos; Vecchi, Stefania; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Vesterinen, Mika; Viaud, Benoit; Vieira, Daniel; Vieites Diaz, Maria; Vilasis-Cardona, Xavier; Vollhardt, Achim; Volyanskyy, Dmytro; Voong, David; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; de Vries, Jacco; Waldi, Roland; Wallace, Charlotte; Wallace, Ronan; Walsh, John; Wandernoth, Sebastian; Wang, Jianchun; Ward, David; Watson, Nigel; Websdale, David; Whitehead, Mark; Wicht, Jean; Wiedner, Dirk; Wilkinson, Guy; Williams, Matthew; Williams, Mike; Wilschut, Hans; Wilson, Fergus; Wimberley, Jack; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wright, Simon; Wyllie, Kenneth; Xie, Yuehong; Xing, Zhou; Xu, Zhirui; Yang, Zhenwei; Yuan, Xuhao; Yushchenko, Oleg; Zangoli, Maria; Zavertyaev, Mikhail; Zhang, Liming; Zhang, Wen Chao; Zhang, Yanxi; Zhelezov, Alexey; Zhokhov, Anatoly; Zhong, Liang; Zvyagin, Alexander

    2014-12-05

    Measuring cross-sections at the LHC requires the luminosity to be determined accurately at each centre-of-mass energy $\\sqrt{s}$. In this paper results are reported from the luminosity calibrations carried out at the LHC interaction point 8 with the LHCb detector for $\\sqrt{s}$ = 2.76, 7 and 8 TeV (proton-proton collisions) and for $\\sqrt{s_{NN}}$ = 5 TeV (proton-lead collisions). Both the "van der Meer scan" and "beam-gas imaging" luminosity calibration methods were employed. It is observed that the beam density profile cannot always be described by a function that is factorizable in the two transverse coordinates. The introduction of a two-dimensional description of the beams improves significantly the consistency of the results. For proton-proton interactions at $\\sqrt{s}$ = 8 TeV a relative precision of the luminosity calibration of 1.47% is obtained using van der Meer scans and 1.43% using beam-gas imaging, resulting in a combined precision of 1.12%. Applying the calibration to the full data set determin...

  5. Laser precision microfabrication in Japan

    Science.gov (United States)

    Miyamoto, Isamu; Ooie, Toshihiko; Takeno, Shozui

    2000-11-01

    Electronic devices such as handy phones and micro computers have been rapidly expanding their market recent years due to their enhanced performance, down sizing and cost down. This has been realized by the innovation in the precision micro- fabrication technology of semiconductors and printed wiring circuit boards (PWB) where laser technologies such as lithography, drilling, trimming, welding and soldering play an important role. In phot lithography, for instance, KrF excimer lasers having a resolution of 0.18 micrometers has been used in production instead of mercury lamp. Laser drilling of PWB has been increased up to over 1000 holes per second, and approximately 800 laser drilling systems of PWB are expected to be delivered in the world market this year, and most of these laser processing systems are manufactured in Japan. Trend of laser micro-fabrication in Japanese industry is described along with recent topics of R&D, government supported project and future tasks of industrial laser precision micro-fabrication on the basis of the survey conducted by Japan laser Processing Society.

  6. Precision experiments in electroweak interactions

    International Nuclear Information System (INIS)

    Swartz, M.L.

    1990-03-01

    The electroweak theory of Glashow, Weinberg, and Salam (GWS) has become one of the twin pillars upon which our understanding of all particle physics phenomena rests. It is a brilliant achievement that qualitatively and quantitatively describes all of the vast quantity of experimental data that have been accumulated over some forty years. Note that the word quantitatively must be qualified. The low energy limiting cases of the GWS theory, Quantum Electrodynamics and the V-A Theory of Weak Interactions, have withstood rigorous testing. The high energy synthesis of these ideas, the GWS theory, has not yet been subjected to comparably precise scrutiny. The recent operation of a new generation of proton-antiproton (p bar p) and electron-positron (e + e - ) colliders has made it possible to produce and study large samples of the electroweak gauge bosons W ± and Z 0 . We expect that these facilities will enable very precise tests of the GWS theory to be performed in the near future. In keeping with the theme of this Institute, Physics at the 100 GeV Mass Scale, these lectures will explore the current status and the near-future prospects of these experiments

  7. Antihydrogen production and precision experiments

    International Nuclear Information System (INIS)

    Nieto, M.M.; Goldman, T.; Holzscheiter, M.H.

    1996-01-01

    The study of CPT invariance with the highest achievable precision in all particle sectors is of fundamental importance for physics. Equally important is the question of the gravitational acceleration of antimatter. In recent years, impressive progress has been achieved in capturing antiprotons in specially designed Penning traps, in cooling them to energies of a few milli-electron volts, and in storing them for hours in a small volume of space. Positrons have been accumulated in large numbers in similar traps, and low energy positron or positronium beams have been generated. Finally, steady progress has been made in trapping and cooling neutral atoms. Thus the ingredients to form antihydrogen at rest are at hand. Once antihydrogen atoms have been captured at low energy, spectroscopic methods can be applied to interrogate their atomic structure with extremely high precision and compare it to its normal matter counterpart, the hydrogen atom. Especially the 1S-2S transition, with a lifetime of the excited state of 122 msec and thereby a natural linewidth of 5 parts in 10 16 , offers in principle the possibility to directly compare matter and antimatter properties at a level of 1 part in 10 16

  8. Laser fusion and precision engineering

    International Nuclear Information System (INIS)

    Nakai, Sadao

    1989-01-01

    The development of laser nuclear fusion energy for attaining the self supply of energy in Japan and establishing the future perspective as the nation is based in the wide fields of high level science and technology. Therefore to its promotion, large expectation is placed as the powerful traction for the development of creative science and technology which are particularly necessary in Japan. The research on laser nuclear fusion advances steadily in the elucidation of the physics of pellet implosion which is its basic concept and compressed plasma parameters. In September, 1986, the number of neutron generation 10 13 , and in October, 1988, the high density compression 600 times as high as solid density have been achieved. Based on these results, now the laser nuclear fusion is in the situation to begin the attainment of ignition condition for nuclear fusion and the realization of break even. The optical components, high power laser technology, fuel pellet production, high resolution measurement, the simulation of implosion using a supercomputer and so on are closely related to precision engineering. In this report, the mechanism of laser nuclear fusion, the present status of its research, and the basic technologies and precision engineering are described. (K.I.)

  9. High-Precision In Situ 87Sr/86Sr Analyses through Microsampling on Solid Samples: Applications to Earth and Life Sciences

    Directory of Open Access Journals (Sweden)

    Sara Di Salvo

    2018-01-01

    Full Text Available An analytical protocol for high-precision, in situ microscale isotopic investigations is presented here, which combines the use of a high-performing mechanical microsampling device and high-precision TIMS measurements on micro-Sr samples, allowing for excellent results both in accuracy and precision. The present paper is a detailed methodological description of the whole analytical procedure from sampling to elemental purification and Sr-isotope measurements. The method offers the potential to attain isotope data at the microscale on a wide range of solid materials with the use of minimally invasive sampling. In addition, we present three significant case studies for geological and life sciences, as examples of the various applications of microscale 87Sr/86Sr isotope ratios, concerning (i the pre-eruptive mechanisms triggering recent eruptions at Nisyros volcano (Greece, (ii the dynamics involved with the initial magma ascent during Eyjafjallajökull volcano’s (Iceland 2010 eruption, which are usually related to the precursory signals of the eruption, and (iii the environmental context of a MIS 3 cave bear, Ursus spelaeus. The studied cases show the robustness of the methods, which can be also be applied in other areas, such as cultural heritage, archaeology, petrology, and forensic sciences.

  10. Methodology For Determination Of Space Control For 3D Reconstruction In Statscan Digital X-Ray Radiology Using Static Frame Model

    Directory of Open Access Journals (Sweden)

    Jacinta S. Kimuyu

    2015-08-01

    Full Text Available The methodology was designed to employ two positioning techniques in order to determine the three-dimensional control space of target points on static metal frame model to be used as space control data in 3D reconstructions in Statscan digital X-Ray imaging. These techniques were digital close-range photogrammetry and precise theodolite positioning method. The space coordinates for the target points were determined 3D using both techniques. Point positioning accuracy 0.5mm in root mean square error of X Y and Z space coordinates was achieved. The outcome of the comparison of the results obtained from both methods were of satisfactory accuracy hence further use of the control space data in Stastcan imaging and 3D reconstruction.

  11. Potential of accuracy profile for method validation in inductively coupled plasma spectrochemistry

    International Nuclear Information System (INIS)

    Mermet, J.M.; Granier, G.

    2012-01-01

    Method validation is usually performed over a range of concentrations for which analytical criteria must be verified. One important criterion in quantitative analysis is accuracy, i.e. the contribution of both trueness and precision. The study of accuracy over this range is called an accuracy profile and provides experimental tolerance intervals. Comparison with acceptability limits fixed by the end user defines a validity domain. This work describes the computation involved in the building of the tolerance intervals, particularly for the intermediate precision with within-laboratory experiments and for the reproducibility with interlaboratory studies. Computation is based on ISO 5725‐4 and on previously published work. Moreover, the bias uncertainty is also computed to verify the bias contribution to accuracy. The various types of accuracy profile behavior are exemplified with results obtained by using ICP-MS and ICP-AES. This procedure allows the analyst to define unambiguously a validity domain for a given accuracy. However, because the experiments are time-consuming, the accuracy profile method is mainly dedicated to method validation. - Highlights: ► An analytical method is defined by its accuracy, i.e. both trueness and precision. ► The accuracy as a function of an analyte concentration is an accuracy profile. ► Profile basic concepts are explained for trueness and intermediate precision. ► Profile-based tolerance intervals have to be compared with acceptability limits. ► Typical accuracy profiles are given for both ICP-AES and ICP-MS techniques.

  12. Scenario development methodologies

    International Nuclear Information System (INIS)

    Eng, T.; Hudson, J.; Stephansson, O.

    1994-11-01

    In the period 1981-1994, SKB has studied several methodologies to systematize and visualize all the features, events and processes (FEPs) that can influence a repository for radioactive waste in the future. All the work performed is based on the terminology and basic findings in the joint SKI/SKB work on scenario development presented in the SKB Technical Report 89-35. The methodologies studied are a) Event tree analysis, b) Influence diagrams and c) Rock Engineering Systems (RES) matrices. Each one of the methodologies is explained in this report as well as examples of applications. One chapter is devoted to a comparison between the two most promising methodologies, namely: Influence diagrams and the RES methodology. In conclusion a combination of parts of the Influence diagram and the RES methodology is likely to be a promising approach. 26 refs

  13. Reliability Centered Maintenance - Methodologies

    Science.gov (United States)

    Kammerer, Catherine C.

    2009-01-01

    Journal article about Reliability Centered Maintenance (RCM) methodologies used by United Space Alliance, LLC (USA) in support of the Space Shuttle Program at Kennedy Space Center. The USA Reliability Centered Maintenance program differs from traditional RCM programs because various methodologies are utilized to take advantage of their respective strengths for each application. Based on operational experience, USA has customized the traditional RCM methodology into a streamlined lean logic path and has implemented the use of statistical tools to drive the process. USA RCM has integrated many of the L6S tools into both RCM methodologies. The tools utilized in the Measure, Analyze, and Improve phases of a Lean Six Sigma project lend themselves to application in the RCM process. All USA RCM methodologies meet the requirements defined in SAE JA 1011, Evaluation Criteria for Reliability-Centered Maintenance (RCM) Processes. The proposed article explores these methodologies.

  14. Precise GPS orbits for geodesy

    Science.gov (United States)

    Colombo, Oscar L.

    1994-01-01

    The Global Positioning System (GPS) has become, in recent years, the main space-based system for surveying and navigation in many military, commercial, cadastral, mapping, and scientific applications. Better receivers, interferometric techniques (DGPS), and advances in post-processing methods have made possible to position fixed or moving receivers with sub-decimeter accuracies in a global reference frame. Improved methods for obtaining the orbits of the GPS satellites have played a major role in these achievements; this paper gives a personal view of the main developments in GPS orbit determination.

  15. Fine structures of atomic excited states: precision atomic spectroscopy and electron-ion collision process

    International Nuclear Information System (INIS)

    Gao Xiang; Cheng Cheng; Li Jiaming

    2011-01-01

    Scientific research fields for future energies such as inertial confinement fusion researches and astrophysics studies especially with satellite observatories advance into stages of precision physics. The relevant atomic data are not only enormous but also of accuracy according to requirements, especially for both energy levels and the collision data. The fine structure of high excited states of atoms and ions can be measured by precision spectroscopy. Such precision measurements can provide not only knowledge about detailed dynamics of electron-ion interactions but also a bench mark examination of the accuracy of electron-ion collision data, especially incorporating theoretical computations. We illustrate that by using theoretical calculation methods which can treat the bound states and the adjacent continua on equal footing. The precision spectroscopic measurements of excited fine structures can be served as stringent tests of electron-ion collision data. (authors)

  16. Measurements of experimental precision for trials with cowpea (Vigna unguiculata L. Walp.) genotypes.

    Science.gov (United States)

    Teodoro, P E; Torres, F E; Santos, A D; Corrêa, A M; Nascimento, M; Barroso, L M A; Ceccon, G

    2016-05-09

    The aim of this study was to evaluate the suitability of statistics as experimental precision degree measures for trials with cowpea (Vigna unguiculata L. Walp.) genotypes. Cowpea genotype yields were evaluated in 29 trials conducted in Brazil between 2005 and 2012. The genotypes were evaluated with a randomized block design with four replications. Ten statistics that were estimated for each trial were compared using descriptive statistics, Pearson correlations, and path analysis. According to the class limits established, selective accuracy and F-test values for genotype, heritability, and the coefficient of determination adequately estimated the degree of experimental precision. Using these statistics, 86.21% of the trials had adequate experimental precision. Selective accuracy and the F-test values for genotype, heritability, and the coefficient of determination were directly related to each other, and were more suitable than the coefficient of variation and the least significant difference (by the Tukey test) to evaluate experimental precision in trials with cowpea genotypes.

  17. Accuracy of five intraoral scanners compared to indirect digitalization.

    Science.gov (United States)

    Güth, Jan-Frederik; Runkel, Cornelius; Beuer, Florian; Stimmelmayr, Michael; Edelhoff, Daniel; Keul, Christine

    2017-06-01

    Direct and indirect digitalization offer two options for computer-aided design (CAD)/ computer-aided manufacturing (CAM)-generated restorations. The aim of this study was to evaluate the accuracy of different intraoral scanners and compare them to the process of indirect digitalization. A titanium testing model was directly digitized 12 times with each intraoral scanner: (1) CS 3500 (CS), (2) Zfx Intrascan (ZFX), (3) CEREC AC Bluecam (BLU), (4) CEREC AC Omnicam (OC) and (5) True Definition (TD). As control, 12 polyether impressions were taken and the referring plaster casts were digitized indirectly with the D-810 laboratory scanner (CON). The accuracy (trueness/precision) of the datasets was evaluated by an analysing software (Geomagic Qualify 12.1) using a "best fit alignment" of the datasets with a highly accurate reference dataset of the testing model, received from industrial computed tomography. Direct digitalization using the TD showed the significant highest overall "trueness", followed by CS. Both performed better than CON. BLU, ZFX and OC showed higher differences from the reference dataset than CON. Regarding the overall "precision", the CS 3500 intraoral scanner and the True Definition showed the best performance. CON, BLU and OC resulted in significantly higher precision than ZFX did. Within the limitations of this in vitro study, the accuracy of the ascertained datasets was dependent on the scanning system. The direct digitalization was not superior to indirect digitalization for all tested systems. Regarding the accuracy, all tested intraoral scanning technologies seem to be able to reproduce a single quadrant within clinical acceptable accuracy. However, differences were detected between the tested systems.

  18. ACCURACY ASSESSMENT OF COASTAL TOPOGRAPHY DERIVED FROM UAV IMAGES

    Directory of Open Access Journals (Sweden)

    N. Long

    2016-06-01

    Full Text Available To monitor coastal environments, Unmanned Aerial Vehicle (UAV is a low-cost and easy to use solution to enable data acquisition with high temporal frequency and spatial resolution. Compared to Light Detection And Ranging (LiDAR or Terrestrial Laser Scanning (TLS, this solution produces Digital Surface Model (DSM with a similar accuracy. To evaluate the DSM accuracy on a coastal environment, a campaign was carried out with a flying wing (eBee combined with a digital camera. Using the Photoscan software and the photogrammetry process (Structure From Motion algorithm, a DSM and an orthomosaic were produced. Compared to GNSS surveys, the DSM accuracy is estimated. Two parameters are tested: the influence of the methodology (number and distribution of Ground Control Points, GCPs and the influence of spatial image resolution (4.6 cm vs 2 cm. The results show that this solution is able to reproduce the topography of a coastal area with a high vertical accuracy (< 10 cm. The georeferencing of the DSM require a homogeneous distribution and a large number of GCPs. The accuracy is correlated with the number of GCPs (use 19 GCPs instead of 10 allows to reduce the difference of 4 cm; the required accuracy should be dependant of the research problematic. Last, in this particular environment, the presence of very small water surfaces on the sand bank does not allow to improve the accuracy when the spatial resolution of images is decreased.

  19. Precise and accurate isotope ratio measurements by ICP-MS.

    Science.gov (United States)

    Becker, J S; Dietze, H J

    2000-09-01

    The precise and accurate determination of isotope ratios by inductively coupled plasma mass spectrometry (ICP-MS) and laser ablation ICP-MS (LA-ICP-MS) is important for quite different application fields (e.g. for isotope ratio measurements of stable isotopes in nature, especially for the investigation of isotope variation in nature or age dating, for determining isotope ratios of radiogenic elements in the nuclear industry, quality assurance of fuel material, for reprocessing plants, nuclear material accounting and radioactive waste control, for tracer experiments using stable isotopes or long-lived radionuclides in biological or medical studies). Thermal ionization mass spectrometry (TIMS), which used to be the dominant analytical technique for precise isotope ratio measurements, is being increasingly replaced for isotope ratio measurements by ICP-MS due to its excellent sensitivity, precision and good accuracy. Instrumental progress in ICP-MS was achieved by the introduction of the collision cell interface in order to dissociate many disturbing argon-based molecular ions, thermalize the ions and neutralize the disturbing argon ions of plasma gas (Ar+). The application of the collision cell in ICP-QMS results in a higher ion transmission, improved sensitivity and better precision of isotope ratio measurements compared to quadrupole ICP-MS without the collision cell [e.g., for 235U/238U approximately 1 (10 microg x L(-1) uranium) 0.07% relative standard deviation (RSD) vs. 0.2% RSD in short-term measurements (n = 5)]. A significant instrumental improvement for ICP-MS is the multicollector device (MC-ICP-MS) in order to obtain a better precision of isotope ratio measurements (with a precision of up to 0.002%, RSD). CE- and HPLC-ICP-MS are used for the separation of isobaric interferences of long-lived radionuclides and stable isotopes by determination of spallation nuclide abundances in an irradiated tantalum target.

  20. Test expectancy affects metacomprehension accuracy.

    Science.gov (United States)

    Thiede, Keith W; Wiley, Jennifer; Griffin, Thomas D

    2011-06-01

    Theory suggests that the accuracy of metacognitive monitoring is affected by the cues used to judge learning. Researchers have improved monitoring accuracy by directing attention to more appropriate cues; however, this is the first study to more directly point students to more appropriate cues using instructions regarding tests and practice tests. The purpose of the present study was to examine whether the accuracy metacognitive monitoring was affected by the nature of the test expected. Students (N= 59) were randomly assigned to one of two test expectancy groups (memory vs. inference). Then after reading texts, judging learning, completed both memory and inference tests. Test performance and monitoring accuracy were superior when students received the kind of test they had been led to expect rather than the unexpected test. Tests influence students' perceptions of what constitutes learning. Our findings suggest that this could affect how students prepare for tests and how they monitoring their own learning. ©2010 The British Psychological Society.