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Sample records for methods comparison study

  1. Comparison Study of Subspace Identification Methods Applied to Flexible Structures

    Science.gov (United States)

    Abdelghani, M.; Verhaegen, M.; Van Overschee, P.; De Moor, B.

    1998-09-01

    In the past few years, various time domain methods for identifying dynamic models of mechanical structures from modal experimental data have appeared. Much attention has been given recently to so-called subspace methods for identifying state space models. This paper presents a detailed comparison study of these subspace identification methods: the eigensystem realisation algorithm with observer/Kalman filter Markov parameters computed from input/output data (ERA/OM), the robust version of the numerical algorithm for subspace system identification (N4SID), and a refined version of the past outputs scheme of the multiple-output error state space (MOESP) family of algorithms. The comparison is performed by simulating experimental data using the five mode reduced model of the NASA Mini-Mast structure. The general conclusion is that for the case of white noise excitations as well as coloured noise excitations, the N4SID/MOESP algorithms perform equally well but give better results (improved transfer function estimates, improved estimates of the output) compared to the ERA/OM algorithm. The key computational step in the three algorithms is the approximation of the extended observability matrix of the system to be identified, for N4SID/MOESP, or of the observer for the system to be identified, for the ERA/OM. Furthermore, the three algorithms only require the specification of one dimensioning parameter.

  2. A simple statistical method for catch comparison studies

    DEFF Research Database (Denmark)

    Holst, René; Revill, Andrew

    2009-01-01

    For analysing catch comparison data, we propose a simple method based on Generalised Linear Mixed Models (GLMM) and use polynomial approximations to fit the proportions caught in the test codend. The method provides comparisons of fish catch at length by the two gears through a continuous curve...... with a realistic confidence band. We demonstrate the versatility of this method, on field data obtained from the first known testing in European waters of the Rhode Island (USA) 'Eliminator' trawl. These data are interesting as they include a range of species with different selective patterns. Crown Copyright (C...

  3. Comparison study on cell calculation method of fast reactor

    International Nuclear Information System (INIS)

    Chiba, Gou

    2002-10-01

    Effective cross sections obtained by cell calculations are used in core calculations in current deterministic methods. Therefore, it is important to calculate the effective cross sections accurately and several methods have been proposed. In this study, some of the methods are compared to each other using a continuous energy Monte Carlo method as a reference. The result shows that the table look-up method used in Japan Nuclear Cycle Development Institute (JNC) sometimes has a difference over 10% in effective microscopic cross sections and be inferior to the sub-group method. The problem was overcome by introducing a new nuclear constant system developed in JNC, in which the ultra free energy group library is used. The system can also deal with resonance interaction effects between nuclides which are not able to be considered by other methods. In addition, a new method was proposed to calculate effective cross section accurately for power reactor fuel subassembly where the new nuclear constant system cannot be applied. This method uses the sub-group method and the ultra fine energy group collision probability method. The microscopic effective cross sections obtained by this method agree with the reference values within 5% difference. (author)

  4. a comparison of methods in a behaviour study of the south african ...

    African Journals Online (AJOL)

    A COMPARISON OF METHODS IN A BEHAVIOUR STUDY OF THE ... Three methods are outlined in this paper and the results obtained from each method were .... There was definitely no aggressive response towards the Sky pointing mate.

  5. Soybean allergen detection methods--a comparison study

    DEFF Research Database (Denmark)

    Pedersen, M. Højgaard; Holzhauser, T.; Bisson, C.

    2008-01-01

    Soybean containing products are widely consumed, thus reliable methods for detection of soy in foods are needed in order to make appropriate risk assessment studies to adequately protect soy allergic patients. Six methods were compared using eight food products with a declared content of soy...

  6. Study and comparison of different methods control in light water critical facility

    International Nuclear Information System (INIS)

    Michaiel, M.L.; Mahmoud, M.S.

    1980-01-01

    The control of nuclear reactors, may be studied using several control methods, such as control by rod absorbers, by inserting or removing fuel rods (moderator cavities), or by changing reflector thickness. Every method has its advantage, the comparison between these different methods and their effect on the reactivity of a reactor is the purpose of this work. A computer program is written by the authors to calculate the critical radius and worth in any case of the three precedent methods of control

  7. Comparison of the xenon-133 washout method with the microsphere method in dog brain perfusion studies

    International Nuclear Information System (INIS)

    Heikkitae, J.; Kettunen, R.; Ahonen, A.

    1982-01-01

    The validity of the Xenon-washout method in estimation of regional cerebral blood flow was tested against a radioactive microsphere method in anaesthetized dogs. The two compartmental model seemed not to be well suited for cerebral perfusion studies by Xe-washout method, although bi-exponential analysis of washout curves gave perfusion values correlating with the microsphere method but depending on calculation method

  8. Comparison of two methods of quantitation in human studies of biodistribution and radiation dosimetry

    International Nuclear Information System (INIS)

    Smith, T.

    1992-01-01

    A simple method of quantitating organ radioactivity content for dosimetry purposes based on relationships between organ count rate and the initial whole body count rate, has been compared with a more rigorous method of absolute quantitation using a transmission scanning technique. Comparisons were on the basis of organ uptake (% administered activity) and resultant organ radiation doses (mGy MBq -1 ) in 6 normal male volunteers given a 99 Tc m -labelled myocardial perfusion imaging agent intravenously at rest and following exercise. In these studies, estimates of individual organ uptakes by the simple method were in error by between +24 and -16% compared with the more accurate method. However, errors on organ dose values were somewhat less and the effective dose was correct to within 3%. (Author)

  9. Comparison of three boosting methods in parent-offspring trios for genotype imputation using simulation study

    Directory of Open Access Journals (Sweden)

    Abbas Mikhchi

    2016-01-01

    Full Text Available Abstract Background Genotype imputation is an important process of predicting unknown genotypes, which uses reference population with dense genotypes to predict missing genotypes for both human and animal genetic variations at a low cost. Machine learning methods specially boosting methods have been used in genetic studies to explore the underlying genetic profile of disease and build models capable of predicting missing values of a marker. Methods In this study strategies and factors affecting the imputation accuracy of parent-offspring trios compared from lower-density SNP panels (5 K to high density (10 K SNP panel using three different Boosting methods namely TotalBoost (TB, LogitBoost (LB and AdaBoost (AB. The methods employed using simulated data to impute the un-typed SNPs in parent-offspring trios. Four different datasets of G1 (100 trios with 5 k SNPs, G2 (100 trios with 10 k SNPs, G3 (500 trios with 5 k SNPs, and G4 (500 trio with 10 k SNPs were simulated. In four datasets all parents were genotyped completely, and offspring genotyped with a lower density panel. Results Comparison of the three methods for imputation showed that the LB outperformed AB and TB for imputation accuracy. The time of computation were different between methods. The AB was the fastest algorithm. The higher SNP densities resulted the increase of the accuracy of imputation. Larger trios (i.e. 500 was better for performance of LB and TB. Conclusions The conclusion is that the three methods do well in terms of imputation accuracy also the dense chip is recommended for imputation of parent-offspring trios.

  10. Study on Comparison of Bidding and Pricing Behavior Distinction between Estimate Methods

    Science.gov (United States)

    Morimoto, Emi; Namerikawa, Susumu

    The most characteristic trend on bidding and pricing behavior distinction in recent years is the increasing number of bidders just above the criteria for low-price bidding investigations. The contractor's markup is the difference between the bidding price and the execution price. Therefore, the contractor's markup is the difference between criteria for low-price bidding investigations price and the execution price in the public works bid in Japan. Virtually, bidder's strategies and behavior have been controlled by public engineer's budgets. Estimation and bid are inseparably linked in the Japanese public works procurement system. The trial of the unit price-type estimation method begins in 2004. On another front, accumulated estimation method is one of the general methods in public works. So, there are two types of standard estimation methods in Japan. In this study, we did a statistical analysis on the bid information of civil engineering works for the Ministry of Land, Infrastructure, and Transportation in 2008. It presents several issues that bidding and pricing behavior is related to an estimation method (several estimation methods) for public works bid in Japan. The two types of standard estimation methods produce different results that number of bidders (decide on bid-no bid strategy) and distribution of bid price (decide on mark-up strategy).The comparison on the distribution of bid prices showed that the percentage of the bid concentrated on the criteria for low-price bidding investigations have had a tendency to get higher in the large-sized public works by the unit price-type estimation method, comparing with the accumulated estimation method. On one hand, the number of bidders who bids for public works estimated unit-price tends to increase significantly Public works estimated unit-price is likely to have been one of the factors for the construction companies to decide if they participate in the biddings.

  11. Matrix diffusion studies by electrical conductivity methods. Comparison between laboratory and in-situ measurements

    International Nuclear Information System (INIS)

    Ohlsson, Y.; Neretnieks, I.

    1998-01-01

    Traditional laboratory diffusion experiments in rock material are time consuming, and quite small samples are generally used. Electrical conductivity measurements, on the other hand, provide a fast means for examining transport properties in rock and allow measurements on larger samples as well. Laboratory measurements using electrical conductivity give results that compare well to those from traditional diffusion experiments. The measurement of the electrical resistivity in the rock surrounding a borehole is a standard method for the detection of water conducting fractures. If these data could be correlated to matrix diffusion properties, in-situ diffusion data from large areas could be obtained. This would be valuable because it would make it possible to obtain data very early in future investigations of potentially suitable sites for a repository. This study compares laboratory electrical conductivity measurements with in-situ resistivity measurements from a borehole at Aespoe. The laboratory samples consist mainly of Aespoe diorite and fine-grained granite and the rock surrounding the borehole of Aespoe diorite, Smaaland granite and fine-grained granite. The comparison shows good agreement between laboratory measurements and in-situ data

  12. Comparison study on qualitative and quantitative risk assessment methods for urban natural gas pipeline network.

    Science.gov (United States)

    Han, Z Y; Weng, W G

    2011-05-15

    In this paper, a qualitative and a quantitative risk assessment methods for urban natural gas pipeline network are proposed. The qualitative method is comprised of an index system, which includes a causation index, an inherent risk index, a consequence index and their corresponding weights. The quantitative method consists of a probability assessment, a consequences analysis and a risk evaluation. The outcome of the qualitative method is a qualitative risk value, and for quantitative method the outcomes are individual risk and social risk. In comparison with previous research, the qualitative method proposed in this paper is particularly suitable for urban natural gas pipeline network, and the quantitative method takes different consequences of accidents into consideration, such as toxic gas diffusion, jet flame, fire ball combustion and UVCE. Two sample urban natural gas pipeline networks are used to demonstrate these two methods. It is indicated that both of the two methods can be applied to practical application, and the choice of the methods depends on the actual basic data of the gas pipelines and the precision requirements of risk assessment. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

  13. Comparison Among Methods of Retinopathy Assessment (CAMRA) Study: Smartphone, Nonmydriatic, and Mydriatic Photography.

    Science.gov (United States)

    Ryan, Martha E; Rajalakshmi, Ramachandran; Prathiba, Vijayaraghavan; Anjana, Ranjit Mohan; Ranjani, Harish; Narayan, K M Venkat; Olsen, Timothy W; Mohan, Viswanathan; Ward, Laura A; Lynn, Michael J; Hendrick, Andrew M

    2015-10-01

    We compared smartphone fundus photography, nonmydriatic fundus photography, and 7-field mydriatic fundus photography for their abilities to detect and grade diabetic retinopathy (DR). This was a prospective, comparative study of 3 photography modalities. Diabetic patients (n = 300) were recruited at the ophthalmology clinic of a tertiary diabetes care center in Chennai, India. Patients underwent photography by all 3 modalities, and photographs were evaluated by 2 retina specialists. The sensitivity and specificity in the detection of DR for both smartphone and nonmydriatic photography were determined by comparison with the standard method, 7-field mydriatic fundus photography. The sensitivity and specificity of smartphone fundus photography, compared with 7-field mydriatic fundus photography, for the detection of any DR were 50% (95% confidence interval [CI], 43-56) and 94% (95% CI, 92-97), respectively, and of nonmydriatic fundus photography were 81% (95% CI, 75-86) and 94% (95% CI, 92-96%), respectively. The sensitivity and specificity of smartphone fundus photography for the detection of vision-threatening DR were 59% (95% CI, 46-72) and 100% (95% CI, 99-100), respectively, and of nonmydriatic fundus photography were 54% (95% CI, 40-67) and 99% (95% CI, 98-100), respectively. Smartphone and nonmydriatic fundus photography are each able to detect DR and sight-threatening disease. However, the nonmydriatic camera is more sensitive at detecting DR than the smartphone. At this time, the benefits of the smartphone (connectivity, portability, and reduced cost) are not offset by the lack of sufficient sensitivity for detection of DR in most clinical circumstances. Copyright © 2015 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  14. Comparison of multiple-criteria decision-making methods - results of simulation study

    Directory of Open Access Journals (Sweden)

    Michał Adamczak

    2016-12-01

    Full Text Available Background: Today, both researchers and practitioners have many methods for supporting the decision-making process. Due to the conditions in which supply chains function, the most interesting are multi-criteria methods. The use of sophisticated methods for supporting decisions requires the parameterization and execution of calculations that are often complex. So is it efficient to use sophisticated methods? Methods: The authors of the publication compared two popular multi-criteria decision-making methods: the  Weighted Sum Model (WSM and the Analytic Hierarchy Process (AHP. A simulation study reflects these two decision-making methods. Input data for this study was a set of criteria weights and the value of each in terms of each criterion. Results: The iGrafx Process for Six Sigma simulation software recreated how both multiple-criteria decision-making methods (WSM and AHP function. The result of the simulation was a numerical value defining the preference of each of the alternatives according to the WSM and AHP methods. The alternative producing a result of higher numerical value  was considered preferred, according to the selected method. In the analysis of the results, the relationship between the values of the parameters and the difference in the results presented by both methods was investigated. Statistical methods, including hypothesis testing, were used for this purpose. Conclusions: The simulation study findings prove that the results obtained with the use of two multiple-criteria decision-making methods are very similar. Differences occurred more frequently in lower-value parameters from the "value of each alternative" group and higher-value parameters from the "weight of criteria" group.

  15. Comparison of three different prehospital wrapping methods for preventing hypothermia - a crossover study in humans

    Directory of Open Access Journals (Sweden)

    Zakariassen Erik

    2011-06-01

    Full Text Available Abstract Background Accidental hypothermia increases mortality and morbidity in trauma patients. Various methods for insulating and wrapping hypothermic patients are used worldwide. The aim of this study was to compare the thermal insulating effects and comfort of bubble wrap, ambulance blankets / quilts, and Hibler's method, a low-cost method combining a plastic outer layer with an insulating layer. Methods Eight volunteers were dressed in moistened clothing, exposed to a cold and windy environment then wrapped using one of the three different insulation methods in random order on three different days. They were rested quietly on their back for 60 minutes in a cold climatic chamber. Skin temperature, rectal temperature, oxygen consumption were measured, and metabolic heat production was calculated. A questionnaire was used for a subjective evaluation of comfort, thermal sensation, and shivering. Results Skin temperature was significantly higher 15 minutes after wrapping using Hibler's method compared with wrapping with ambulance blankets / quilts or bubble wrap. There were no differences in core temperature between the three insulating methods. The subjects reported more shivering, they felt colder, were more uncomfortable, and had an increased heat production when using bubble wrap compared with the other two methods. Hibler's method was the volunteers preferred method for preventing hypothermia. Bubble wrap was the least effective insulating method, and seemed to require significantly higher heat production to compensate for increased heat loss. Conclusions This study demonstrated that a combination of vapour tight layer and an additional dry insulating layer (Hibler's method is the most efficient wrapping method to prevent heat loss, as shown by increased skin temperatures, lower metabolic rate and better thermal comfort. This should then be the method of choice when wrapping a wet patient at risk of developing hypothermia in prehospital

  16. Comparison of Three Methods of Reducing Test Anxiety: Systematic Desensitization, Implosive Therapy, and Study Counseling

    Science.gov (United States)

    Cornish, Richard D.; Dilley, Josiah S.

    1973-01-01

    Systematic desensitization, implosive therapy, and study counseling have all been effective in reducing test anxiety. In addition, systematic desensitization has been compared to study counseling for effectiveness. This study compares all three methods and suggests that systematic desentization is more effective than the others, and that implosive…

  17. Gene Expression Profiles for Predicting Metastasis in Breast Cancer: A Cross-Study Comparison of Classification Methods

    Directory of Open Access Journals (Sweden)

    Mark Burton

    2012-01-01

    Full Text Available Machine learning has increasingly been used with microarray gene expression data and for the development of classifiers using a variety of methods. However, method comparisons in cross-study datasets are very scarce. This study compares the performance of seven classification methods and the effect of voting for predicting metastasis outcome in breast cancer patients, in three situations: within the same dataset or across datasets on similar or dissimilar microarray platforms. Combining classification results from seven classifiers into one voting decision performed significantly better during internal validation as well as external validation in similar microarray platforms than the underlying classification methods. When validating between different microarray platforms, random forest, another voting-based method, proved to be the best performing method. We conclude that voting based classifiers provided an advantage with respect to classifying metastasis outcome in breast cancer patients.

  18. Aggregation Methods in International Comparisons

    NARCIS (Netherlands)

    B.M. Balk (Bert)

    2001-01-01

    textabstractThis paper reviews the progress that has been made over the past decade in understanding the nature of the various multilateral in- ternational comparison methods. Fifteen methods are discussed and subjected to a system of ten tests. In addition, attention is paid to recently developed

  19. Multi-reader ROC studies with split-plot designs: a comparison of statistical methods.

    Science.gov (United States)

    Obuchowski, Nancy A; Gallas, Brandon D; Hillis, Stephen L

    2012-12-01

    Multireader imaging trials often use a factorial design, in which study patients undergo testing with all imaging modalities and readers interpret the results of all tests for all patients. A drawback of this design is the large number of interpretations required of each reader. Split-plot designs have been proposed as an alternative, in which one or a subset of readers interprets all images of a sample of patients, while other readers interpret the images of other samples of patients. In this paper, the authors compare three methods of analysis for the split-plot design. Three statistical methods are presented: the Obuchowski-Rockette method modified for the split-plot design, a newly proposed marginal-mean analysis-of-variance approach, and an extension of the three-sample U-statistic method. A simulation study using the Roe-Metz model was performed to compare the type I error rate, power, and confidence interval coverage of the three test statistics. The type I error rates for all three methods are close to the nominal level but tend to be slightly conservative. The statistical power is nearly identical for the three methods. The coverage of 95% confidence intervals falls close to the nominal coverage for small and large sample sizes. The split-plot multireader, multicase study design can be statistically efficient compared to the factorial design, reducing the number of interpretations required per reader. Three methods of analysis, shown to have nominal type I error rates, similar power, and nominal confidence interval coverage, are available for this study design. Copyright © 2012 AUR. All rights reserved.

  20. Comparison of different methods for work accidents investigation in hospitals: A Portuguese case study.

    Science.gov (United States)

    Nunes, Cláudia; Santos, Joana; da Silva, Manuela Vieira; Lourenço, Irina; Carvalhais, Carlos

    2015-01-01

    The hospital environment has many occupational health risks that predispose healthcare workers to various kinds of work accidents. This study aims to compare different methods for work accidents investigation and to verify their suitability in hospital environment. For this purpose, we selected three types of accidents that were related with needle stick, worker fall and inadequate effort/movement during the mobilization of patients. A total of thirty accidents were analysed with six different work accidents investigation methods. The results showed that organizational factors were the group of causes which had the greatest impact in the three types of work accidents. The methods selected to be compared in this paper are applicable and appropriate for the work accidents investigation in hospitals. However, the Registration, Research and Analysis of Work Accidents method (RIAAT) showed to be an optimal technique to use in this context.

  1. Comparison of methods of extracting information for meta-analysis of observational studies in nutritional epidemiology

    Directory of Open Access Journals (Sweden)

    Jong-Myon Bae

    2016-01-01

    Full Text Available OBJECTIVES: A common method for conducting a quantitative systematic review (QSR for observational studies related to nutritional epidemiology is the “highest versus lowest intake” method (HLM, in which only the information concerning the effect size (ES of the highest category of a food item is collected on the basis of its lowest category. However, in the interval collapsing method (ICM, a method suggested to enable a maximum utilization of all available information, the ES information is collected by collapsing all categories into a single category. This study aimed to compare the ES and summary effect size (SES between the HLM and ICM. METHODS: A QSR for evaluating the citrus fruit intake and risk of pancreatic cancer and calculating the SES by using the HLM was selected. The ES and SES were estimated by performing a meta-analysis using the fixed-effect model. The directionality and statistical significance of the ES and SES were used as criteria for determining the concordance between the HLM and ICM outcomes. RESULTS: No significant differences were observed in the directionality of SES extracted by using the HLM or ICM. The application of the ICM, which uses a broader information base, yielded more-consistent ES and SES, and narrower confidence intervals than the HLM. CONCLUSIONS: The ICM is advantageous over the HLM owing to its higher statistical accuracy in extracting information for QSR on nutritional epidemiology. The application of the ICM should hence be recommended for future studies.

  2. Comparison of the effectiveness of sterilizing endodontic files by 4 different methods: An in vitro study

    Directory of Open Access Journals (Sweden)

    Venkatasubramanian R

    2010-03-01

    Full Text Available Sterilization is the best method to counter the threats of microorganisms. The purpose of sterilization in the field of health care is to prevent the spread of infectious diseases. In dentistry, it primarily relates to processing reusable instruments to prevent cross-infection. The aim of this study was to investigate the efficacy of 4 methods of sterilizing endodontic instruments: Autoclaving, carbon dioxide laser sterilization, chemical sterilization (with glutaraldehyde and glass-bead sterilization. The endodontic file was sterilized by 4 different methods after contaminating it with bacillus stearothermophillus and then checked for sterility by incubating after putting it in test tubes containing thioglycollate medium. The study showed that the files sterilized by autoclave and lasers were completely sterile. Those sterilized by glass bead were 90% sterile and those with glutaraldehyde were 80% sterile. The study concluded that autoclave or laser could be used as a method of sterilization in clinical practice and in advanced clinics; laser can be used also as a chair side method of sterilization.

  3. Mapping biomass with remote sensing: a comparison of methods for the case study of Uganda

    Directory of Open Access Journals (Sweden)

    Henry Matieu

    2011-10-01

    Full Text Available Abstract Background Assessing biomass is gaining increasing interest mainly for bioenergy, climate change research and mitigation activities, such as reducing emissions from deforestation and forest degradation and the role of conservation, sustainable management of forests and enhancement of forest carbon stocks in developing countries (REDD+. In response to these needs, a number of biomass/carbon maps have been recently produced using different approaches but the lack of comparable reference data limits their proper validation. The objectives of this study are to compare the available maps for Uganda and to understand the sources of variability in the estimation. Uganda was chosen as a case-study because it presents a reliable national biomass reference dataset. Results The comparison of the biomass/carbon maps show strong disagreement between the products, with estimates of total aboveground biomass of Uganda ranging from 343 to 2201 Tg and different spatial distribution patterns. Compared to the reference map based on country-specific field data and a national Land Cover (LC dataset (estimating 468 Tg, maps based on biome-average biomass values, such as the Intergovernmental Panel on Climate Change (IPCC default values, and global LC datasets tend to strongly overestimate biomass availability of Uganda (ranging from 578 to 2201 Tg, while maps based on satellite data and regression models provide conservative estimates (ranging from 343 to 443 Tg. The comparison of the maps predictions with field data, upscaled to map resolution using LC data, is in accordance with the above findings. This study also demonstrates that the biomass estimates are primarily driven by the biomass reference data while the type of spatial maps used for their stratification has a smaller, but not negligible, impact. The differences in format, resolution and biomass definition used by the maps, as well as the fact that some datasets are not independent from the

  4. Comparison of two inductive learning methods: A case study in failed fuel identification

    International Nuclear Information System (INIS)

    Reifman, J.; Lee, J.C.

    1992-01-01

    Two inductive learning methods, the ID3 and Rg algorithms, are studied as a means for systematically and automatically constructing the knowledge base of expert systems. Both inductive learning methods are general-purpose and use information entropy as a discriminatory measure in order to group objects of a common class. ID3 constructs a knowledge base by building decision trees that discriminate objects of a data set as a function of their class. Rg constructs a knowledge base by grouping objects of the same class into patterns or clusters. The two inductive methods are applied to the construction of a knowledge base for failed fuel identification in the Experimental Breeder Reactor II. Through analysis of the knowledge bases generated, the ID3 and Rg algorithms are compared for their knowledge representation, data overfitting, feature space partition, feature selection, and search procedure

  5. Comparison of two inductive learning methods: A case study in failed fuel identification

    Energy Technology Data Exchange (ETDEWEB)

    Reifman, J. [Argonne National Lab., IL (United States); Lee, J.C. [Michigan Univ., Ann Arbor, MI (United States). Dept. of Nuclear Engineering

    1992-05-01

    Two inductive learning methods, the ID3 and Rg algorithms, are studied as a means for systematically and automatically constructing the knowledge base of expert systems. Both inductive learning methods are general-purpose and use information entropy as a discriminatory measure in order to group objects of a common class. ID3 constructs a knowledge base by building decision trees that discriminate objects of a data set as a function of their class. Rg constructs a knowledge base by grouping objects of the same class into patterns or clusters. The two inductive methods are applied to the construction of a knowledge base for failed fuel identification in the Experimental Breeder Reactor II. Through analysis of the knowledge bases generated, the ID3 and Rg algorithms are compared for their knowledge representation, data overfitting, feature space partition, feature selection, and search procedure.

  6. Comparison of two inductive learning methods: A case study in failed fuel identification

    Energy Technology Data Exchange (ETDEWEB)

    Reifman, J. (Argonne National Lab., IL (United States)); Lee, J.C. (Michigan Univ., Ann Arbor, MI (United States). Dept. of Nuclear Engineering)

    1992-01-01

    Two inductive learning methods, the ID3 and Rg algorithms, are studied as a means for systematically and automatically constructing the knowledge base of expert systems. Both inductive learning methods are general-purpose and use information entropy as a discriminatory measure in order to group objects of a common class. ID3 constructs a knowledge base by building decision trees that discriminate objects of a data set as a function of their class. Rg constructs a knowledge base by grouping objects of the same class into patterns or clusters. The two inductive methods are applied to the construction of a knowledge base for failed fuel identification in the Experimental Breeder Reactor II. Through analysis of the knowledge bases generated, the ID3 and Rg algorithms are compared for their knowledge representation, data overfitting, feature space partition, feature selection, and search procedure.

  7. Quantitative methods for reconstructing tissue biomechanical properties in optical coherence elastography: a comparison study

    International Nuclear Information System (INIS)

    Han, Zhaolong; Li, Jiasong; Singh, Manmohan; Wu, Chen; Liu, Chih-hao; Wang, Shang; Idugboe, Rita; Raghunathan, Raksha; Sudheendran, Narendran; Larin, Kirill V; Aglyamov, Salavat R; Twa, Michael D

    2015-01-01

    We present a systematic analysis of the accuracy of five different methods for extracting the biomechanical properties of soft samples using optical coherence elastography (OCE). OCE is an emerging noninvasive technique, which allows assessment of biomechanical properties of tissues with micrometer spatial resolution. However, in order to accurately extract biomechanical properties from OCE measurements, application of a proper mechanical model is required. In this study, we utilize tissue-mimicking phantoms with controlled elastic properties and investigate the feasibilities of four available methods for reconstructing elasticity (Young’s modulus) based on OCE measurements of an air-pulse induced elastic wave. The approaches are based on the shear wave equation (SWE), the surface wave equation (SuWE), Rayleigh-Lamb frequency equation (RLFE), and finite element method (FEM), Elasticity values were compared with uniaxial mechanical testing. The results show that the RLFE and the FEM are more robust in quantitatively assessing elasticity than the other simplified models. This study provides a foundation and reference for reconstructing the biomechanical properties of tissues from OCE data, which is important for the further development of noninvasive elastography methods. (paper)

  8. Comparison of radioimmunological and enzyme-immunological methods of determination in thyroid function studies

    International Nuclear Information System (INIS)

    Arnold, L.P.

    1984-01-01

    During the study described here parallel investigations were carried out using radio-immuno-assays (RIA) and enzyme-immuno-assays (EIA) in order to assess the quality and diagnostic value of both these techniques as well as to weigh up their relative advantages and disadvantages in connection with thyroid function studies. The following comparisons were made: T4 RIA versus T4 EIA, T3 RIA versus T3 EIA, T3 uptake versus thyroxine binding capacity, total balance of free hormone bonds. Correlation coefficients of 0.982 for T4 and 0.989 for T3 proved that the test results obtained using either RIA or EIA were in fairly good agreement. Less satisfactory correlation was suggested by a coefficient of 0.807 between the tests for thyroxine binding capacity and T3 uptake, which was even seen to decrease with increasing binding capacity so that the greatest deviations were observed in hyperthyroidism. The same holds true for the free T4 index and total balance, where the correlation coefficient is altered in a similar way by the inclusion of a thyroxine binding capacity EIA. Better agreement was achieved by optimal adjustment of the defined diagnostic ranges for hypothyroidism, euthyroidism and hyperthyroidism. The EIA results were biassed in the presence of hyperbilirubinemia. Intra-assay abd inter-assay veriations were analysed and found to range from 8.1 to 16.9% and 13.6 to 28.1%, respectively. EIA offers advantages over RIA inasmuch as it is free from radioactivity and does not require any special safety measures, although it was judged considerably less favourable than RIA in terms of sensitivity. (TRV) [de

  9. A study on asymptomatic bacteriuria in pregnancy: prevalence, etiology and comparison of screening methods

    OpenAIRE

    Kheya Mukherjee; Saroj Golia; Vasudha CL; Babita; Debojyoti Bhattacharjee; Goutam Chakroborti

    2014-01-01

    Background: Asymptomatic bacteriuria is common in women with prevalence of 4-7% in pregnancy. The traditional reference test for bacteriuria is quantitative culture of urine which is relatively expensive time consuming and laborious. The aim of this study was to know the prevalence of asymptomatic bacteriuria in pregnancy, to identify pathogens and their antibiotic susceptibility patterns and to device a single or combined rapid screening method as an acceptable alternative to urine culture. ...

  10. Comparison of three methods of calculating strain in the mouse ulna in exogenous loading studies.

    Science.gov (United States)

    Norman, Stephanie C; Wagner, David W; Beaupre, Gary S; Castillo, Alesha B

    2015-01-02

    Axial compression of mouse limbs is commonly used to induce bone formation in a controlled, non-invasive manner. Determination of peak strains caused by loading is central to interpreting results. Load-strain calibration is typically performed using uniaxial strain gauges attached to the diaphyseal, periosteal surface of a small number of sacrificed animals. Strain is measured as the limb is loaded to a range of physiological loads known to be anabolic to bone. The load-strain relationship determined by this subgroup is then extrapolated to a larger group of experimental mice. This method of strain calculation requires the challenging process of strain gauging very small bones which is subject to variability in placement of the strain gauge. We previously developed a method to estimate animal-specific periosteal strain during axial ulnar loading using an image-based computational approach that does not require strain gauges. The purpose of this study was to compare the relationship between load-induced bone formation rates and periosteal strain at ulnar midshaft using three different methods to estimate strain: (A) Nominal strain values based solely on load-strain calibration; (B) Strains calculated from load-strain calibration, but scaled for differences in mid-shaft cross-sectional geometry among animals; and (C) An alternative image-based computational method for calculating strains based on beam theory and animal-specific bone geometry. Our results show that the alternative method (C) provides comparable correlation between strain and bone formation rates in the mouse ulna relative to the strain gauge-dependent methods (A and B), while avoiding the need to use strain gauges. Published by Elsevier Ltd.

  11. Comparison between Two Radiological Methods for Assessment of Tooth Root Resorption: An In Vitro Study

    Directory of Open Access Journals (Sweden)

    Sabina Saccomanno

    2018-01-01

    Full Text Available Purpose. This study aims to verify the validity of the radiographic image and the most effective radiological techniques for the diagnosis of root resorption to prevent, cure, and reduce it and to verify if radiological images can be helpful in medical and legal situations. Methods. 19 dental elements without root resorption extracted from several patients were examined: endooral and panoramic radiographs were performed, with traditional and digital methods. Then the root of each tooth was dipped into 3-4 mm of 10% nitric acid for 24 hours to simulate the resorption of the root and later submitted again to radiological examinations and measurements using the same criteria and methods. Results. For teeth with root resorption the real measurements and the values obtained with endooral techniques and digital sensors are almost the same, while image values obtained by panoramic radiographs are more distorted than the real ones. Conclusions. Panoramic radiographs are not useful for the diagnosis of root resorption. The endooral examination is, in medical and legal fields, the most valid and objective instrument to detect root resorption. Although the literature suggests that CBCT is a reliable tool in detecting root resorption defects, the increased radiation dosage and expense and the limited availability of CBCT in most clinical settings accentuate the outcome of this study.

  12. A comparison between NASCET and ECST methods in the study of carotids

    International Nuclear Information System (INIS)

    Saba, Luca; Mallarini, Giorgio

    2010-01-01

    Purpose: NASCET and ECST systems to quantify carotid artery stenosis use percent diameter ratios from conventional angiography. With the use of Multi-Detector-Row CT scanners it is possible to easily measure plaque area and residual lumen in order to calculate carotid stenosis degree. Our purpose was to compare NASCET and ECST techniques in the measurement of carotid stenosis degree by using MDCTA. Methods and material: From February 2007 to October 2007, 83 non-consecutive patients (68 males; 15 females) were studied using Multi-Detector-Row CT. Each patient was assessed by two experienced radiologists for stenosis degree by using both NASCET and ECST methods. Statistic analysis was performed to determine the entity of correlation (method of Pearson) between NASCET and ECST. The Cohen kappa test and Bland-Altman analysis were applied to assess the level of inter- and intra-observer agreement. Results: The correlation Pearson coefficient between NASCET and ECST was 0.962 (p < 0.01). Intra-observer agreement in the NASCET evaluation, by using Cohen statistic was 0.844 and 0.825. Intra-observer agreement in the ECST evaluation was 0.871 and 0.836. Inter-observer agreement in the NASCET and ECTS were 0.822 and 0.834, respectively. Agreement analysis by using Bland-Altman plots showed a good intra-/inter-observer agreement for the NASCET and an optimal intra-/inter-observer agreement for the ECST. Conclusions: Results of our study suggest that NASCET and ECST methods show a strength correlation according to quadratic regression. Intra-observer agreement results high for both NASCET and ECST.

  13. Bioanalysis works in the IAA AMS facility: Comparison of AMS analytical method with LSC method in human mass balance study

    International Nuclear Information System (INIS)

    Miyaoka, Teiji; Isono, Yoshimi; Setani, Kaoru; Sakai, Kumiko; Yamada, Ichimaro; Sato, Yoshiaki; Gunji, Shinobu; Matsui, Takao

    2007-01-01

    Institute of Accelerator Analysis Ltd. (IAA) is the first Contract Research Organization in Japan providing Accelerator Mass Spectrometry (AMS) analysis services for carbon dating and bioanalysis works. The 3 MV AMS machines are maintained by validated analysis methods using multiple control compounds. It is confirmed that these AMS systems have reliabilities and sensitivities enough for each objective. The graphitization of samples for bioanalysis is prepared by our own purification lines including the measurement of total carbon content in the sample automatically. In this paper, we present the use of AMS analysis in human mass balance and metabolism profiling studies with IAA 3 MV AMS, comparing results obtained from the same samples with liquid scintillation counting (LSC). Human samples such as plasma, urine and feces were obtained from four healthy volunteers orally administered a 14 C-labeled drug Y-700, a novel xanthine oxidase inhibitor, of which radioactivity was about 3 MBq (85 μCi). For AMS measurement, these samples were diluted 100-10,000-fold with pure-water or blank samples. The results indicated that AMS method had a good correlation with LSC method (e.g. plasma: r = 0.998, urine: r = 0.997, feces: r = 0.997), and that the drug recovery in the excreta exceeded 92%. The metabolite profiles of plasma, urine and feces obtained with HPLC-AMS corresponded to radio-HPLC results measured at much higher radioactivity level. These results revealed that AMS analysis at IAA is useful to measure 14 C-concentration in bioanalysis studies at very low radioactivity level

  14. Comparison of methods for calculating the health costs of endocrine disrupters: a case study on triclosan.

    Science.gov (United States)

    Prichystalova, Radka; Fini, Jean-Baptiste; Trasande, Leonardo; Bellanger, Martine; Demeneix, Barbara; Maxim, Laura

    2017-06-09

    Socioeconomic analysis is currently used in the Europe Union as part of the regulatory process in Regulation Registration, Evaluation and Authorisation of Chemicals (REACH), with the aim of assessing and managing risks from dangerous chemicals. The political impact of the socio-economic analysis is potentially high in the authorisation and restriction procedures, however, current socio-economic analysis dossiers submitted under REACH are very heterogeneous in terms of methodology used and quality. Furthermore, the economic literature is not very helpful for regulatory purposes, as most published calculations of health costs associated with chemical exposures use epidemiological studies as input data, but such studies are rarely available for most substances. The quasi-totality of the data used in the REACH dossiers comes from toxicological studies. This paper assesses the use of the integrated probabilistic risk assessment, based on toxicological data, for the calculation of health costs associated with endocrine disrupting effects of triclosan. The results are compared with those obtained using the population attributable fraction, based on epidemiological data. The results based on the integrated probabilistic risk assessment indicated that 4894 men could have reproductive deficits based on the decreased vas deferens weights observed in rats, 0 cases of changed T 3 levels, and 0 cases of girls with early pubertal development. The results obtained with the Population Attributable Fraction method showed 7,199,228 cases of obesity per year, 281,923 girls per year with early pubertal development and 88,957 to 303,759 cases per year with increased total T 3 hormone levels. The economic costs associated with increased BMI due to TCS exposure could be calculated. Direct health costs were estimated at €5.8 billion per year. The two methods give very different results for the same effects. The choice of a toxicological-based or an epidemiological-based method in the

  15. Comparison of Three Popular Methods for Recruiting Young Persons Who Inject Drugs for Interventional Studies.

    Science.gov (United States)

    Collier, Melissa G; Garfein, Richard S; Cuevas-Mota, Jazmine; Teshale, Eyasu H

    2017-08-01

    Persons who inject drugs (PWID) are at risk for adverse health outcomes as a result of their drug use, and the resulting social stigma makes this a difficult population to reach for interventions aimed at reducing morbidity and mortality. During our study of adult PWID aged ≤40 years living in San Diego during 2009 and 2010, we compared three different sampling methods: respondent-driven sampling (RDS), venue-based sampling at one syringe exchange program (SEP), and street-based outreach. We compared demographic, socioeconomic, health, and behavioral factors and tested participants for HIV, hepatitis B virus (HBV), and hepatitis C virus (HCV) and compared across the three methods. Overall, 561 (74.8%) of the targeted 750 PWID were enrolled. Venue-based convenience sampling enrolled 96% (242/250) of the targeted participants, followed closely by street-based outreach with 92% (232/250) recruited. While RDS yielded the fewest recruits, producing only 35% (87/250) of the expected participants, those recruited through RDS were more likely to be female, more racially diverse, and younger.

  16. A comparison of five methods of measuring mammographic density: a case-control study.

    Science.gov (United States)

    Astley, Susan M; Harkness, Elaine F; Sergeant, Jamie C; Warwick, Jane; Stavrinos, Paula; Warren, Ruth; Wilson, Mary; Beetles, Ursula; Gadde, Soujanya; Lim, Yit; Jain, Anil; Bundred, Sara; Barr, Nicola; Reece, Valerie; Brentnall, Adam R; Cuzick, Jack; Howell, Tony; Evans, D Gareth

    2018-02-05

    High mammographic density is associated with both risk of cancers being missed at mammography, and increased risk of developing breast cancer. Stratification of breast cancer prevention and screening requires mammographic density measures predictive of cancer. This study compares five mammographic density measures to determine the association with subsequent diagnosis of breast cancer and the presence of breast cancer at screening. Women participating in the "Predicting Risk Of Cancer At Screening" (PROCAS) study, a study of cancer risk, completed questionnaires to provide personal information to enable computation of the Tyrer-Cuzick risk score. Mammographic density was assessed by visual analogue scale (VAS), thresholding (Cumulus) and fully-automated methods (Densitas, Quantra, Volpara) in contralateral breasts of 366 women with unilateral breast cancer (cases) detected at screening on entry to the study (Cumulus 311/366) and in 338 women with cancer detected subsequently. Three controls per case were matched using age, body mass index category, hormone replacement therapy use and menopausal status. Odds ratios (OR) between the highest and lowest quintile, based on the density distribution in controls, for each density measure were estimated by conditional logistic regression, adjusting for classic risk factors. The strongest predictor of screen-detected cancer at study entry was VAS, OR 4.37 (95% CI 2.72-7.03) in the highest vs lowest quintile of percent density after adjustment for classical risk factors. Volpara, Densitas and Cumulus gave ORs for the highest vs lowest quintile of 2.42 (95% CI 1.56-3.78), 2.17 (95% CI 1.41-3.33) and 2.12 (95% CI 1.30-3.45), respectively. Quantra was not significantly associated with breast cancer (OR 1.02, 95% CI 0.67-1.54). Similar results were found for subsequent cancers, with ORs of 4.48 (95% CI 2.79-7.18), 2.87 (95% CI 1.77-4.64) and 2.34 (95% CI 1.50-3.68) in highest vs lowest quintiles of VAS, Volpara and Densitas

  17. Comparison of matrix method and ray tracing in the study of complex optical systems

    Science.gov (United States)

    Anterrieu, Eric; Perez, Jose-Philippe

    2000-06-01

    In the context of the classical study of optical systems within the geometrical Gauss approximation, the cardinal elements are efficiently obtained with the aid of the transfer matrix between the input and output planes of the system. In order to take into account the geometrical aberrations, a ray tracing approach, using the Snell- Descartes laws, has been implemented in an interactive software. Both methods are applied for measuring the correction to be done to a human eye suffering from ametropia. This software may be used by optometrists and ophthalmologists for solving the problems encountered when considering this pathology. The ray tracing approach gives a significant improvement and could be very helpful for a better understanding of an eventual surgical act.

  18. Variable selection methods in PLS regression - a comparison study on metabolomics data

    DEFF Research Database (Denmark)

    Karaman, İbrahim; Hedemann, Mette Skou; Knudsen, Knud Erik Bach

    . The aim of the metabolomics study was to investigate the metabolic profile in pigs fed various cereal fractions with special attention to the metabolism of lignans using LC-MS based metabolomic approach. References 1. Lê Cao KA, Rossouw D, Robert-Granié C, Besse P: A Sparse PLS for Variable Selection when...... integrated approach. Due to the high number of variables in data sets (both raw data and after peak picking) the selection of important variables in an explorative analysis is difficult, especially when different data sets of metabolomics data need to be related. Variable selection (or removal of irrelevant...... different strategies for variable selection on PLSR method were considered and compared with respect to selected subset of variables and the possibility for biological validation. Sparse PLSR [1] as well as PLSR with Jack-knifing [2] was applied to data in order to achieve variable selection prior...

  19. Comparison of field swept ferromagnetic resonance methods - A case study using Ni-Mn-Sn films

    Science.gov (United States)

    Modak, R.; Samantaray, B.; Mandal, P.; Srinivasu, V. V.; Srinivasan, A.

    2018-05-01

    Ferromagnetic resonance spectroscopy is used to understand the magnetic behavior of Ni-Mn-Sn Heusler alloy film. Two popular experimental methods available for recording FMR spectra are presented here. In plane angular (φH) variation of magnetic relaxation is used to evaluate the in plane anisotropy (Ku) of the film. The out of plane (θH) variation of FMR spectra has been numerically analyzed to extract the Gilbert damping coefficient, effective magnetization and perpendicular magnetic anisotropy (K1). Magnetic homogeneity of the film had also been evaluated in terms of 2-magnon contribution from FMR linewidth. The advantage and limitations of these two popular FMR techniques are discussed on the basis of the results obtained in this comparative study.

  20. Comparison of manual versus automated data collection method for an evidence-based nursing practice study.

    Science.gov (United States)

    Byrne, M D; Jordan, T R; Welle, T

    2013-01-01

    The objective of this study was to investigate and improve the use of automated data collection procedures for nursing research and quality assurance. A descriptive, correlational study analyzed 44 orthopedic surgical patients who were part of an evidence-based practice (EBP) project examining post-operative oxygen therapy at a Midwestern hospital. The automation work attempted to replicate a manually-collected data set from the EBP project. Automation was successful in replicating data collection for study data elements that were available in the clinical data repository. The automation procedures identified 32 "false negative" patients who met the inclusion criteria described in the EBP project but were not selected during the manual data collection. Automating data collection for certain data elements, such as oxygen saturation, proved challenging because of workflow and practice variations and the reliance on disparate sources for data abstraction. Automation also revealed instances of human error including computational and transcription errors as well as incomplete selection of eligible patients. Automated data collection for analysis of nursing-specific phenomenon is potentially superior to manual data collection methods. Creation of automated reports and analysis may require initial up-front investment with collaboration between clinicians, researchers and information technology specialists who can manage the ambiguities and challenges of research and quality assurance work in healthcare.

  1. The continual reassessment method: comparison of Bayesian stopping rules for dose-ranging studies.

    Science.gov (United States)

    Zohar, S; Chevret, S

    2001-10-15

    The continual reassessment method (CRM) provides a Bayesian estimation of the maximum tolerated dose (MTD) in phase I clinical trials and is also used to estimate the minimal efficacy dose (MED) in phase II clinical trials. In this paper we propose Bayesian stopping rules for the CRM, based on either posterior or predictive probability distributions that can be applied sequentially during the trial. These rules aim at early detection of either the mis-choice of dose range or a prefixed gain in the point estimate or accuracy of estimated probability of response associated with the MTD (or MED). They were compared through a simulation study under six situations that could represent the underlying unknown dose-response (either toxicity or failure) relationship, in terms of sample size, probability of correct selection and bias of the response probability associated to the MTD (or MED). Our results show that the stopping rules act correctly, with early stopping by using the two first rules based on the posterior distribution when the actual underlying dose-response relationship is far from that initially supposed, while the rules based on predictive gain functions provide a discontinuation of inclusions whatever the actual dose-response curve after 20 patients on average, that is, depending mostly on the accumulated data. The stopping rules were then applied to a data set from a dose-ranging phase II clinical trial aiming at estimating the MED dose of midazolam in the sedation of infants during cardiac catheterization. All these findings suggest the early use of the two first rules to detect a mis-choice of dose range, while they confirm the requirement of including at least 20 patients at the same dose to reach an accurate estimate of MTD (MED). A two-stage design is under study. Copyright 2001 John Wiley & Sons, Ltd.

  2. A comparison study of size-specific dose estimate calculation methods

    Energy Technology Data Exchange (ETDEWEB)

    Parikh, Roshni A. [Rainbow Babies and Children' s Hospital, University Hospitals Cleveland Medical Center, Case Western Reserve University School of Medicine, Department of Radiology, Cleveland, OH (United States); University of Michigan Health System, Department of Radiology, Ann Arbor, MI (United States); Wien, Michael A.; Jordan, David W.; Ciancibello, Leslie; Berlin, Sheila C. [Rainbow Babies and Children' s Hospital, University Hospitals Cleveland Medical Center, Case Western Reserve University School of Medicine, Department of Radiology, Cleveland, OH (United States); Novak, Ronald D. [Rainbow Babies and Children' s Hospital, University Hospitals Cleveland Medical Center, Case Western Reserve University School of Medicine, Department of Radiology, Cleveland, OH (United States); Rebecca D. Considine Research Institute, Children' s Hospital Medical Center of Akron, Center for Mitochondrial Medicine Research, Akron, OH (United States); Klahr, Paul [CT Clinical Science, Philips Healthcare, Highland Heights, OH (United States); Soriano, Stephanie [Rainbow Babies and Children' s Hospital, University Hospitals Cleveland Medical Center, Case Western Reserve University School of Medicine, Department of Radiology, Cleveland, OH (United States); University of Washington, Department of Radiology, Seattle, WA (United States)

    2018-01-15

    The size-specific dose estimate (SSDE) has emerged as an improved metric for use by medical physicists and radiologists for estimating individual patient dose. Several methods of calculating SSDE have been described, ranging from patient thickness or attenuation-based (automated and manual) measurements to weight-based techniques. To compare the accuracy of thickness vs. weight measurement of body size to allow for the calculation of the size-specific dose estimate (SSDE) in pediatric body CT. We retrospectively identified 109 pediatric body CT examinations for SSDE calculation. We examined two automated methods measuring a series of level-specific diameters of the patient's body: method A used the effective diameter and method B used the water-equivalent diameter. Two manual methods measured patient diameter at two predetermined levels: the superior endplate of L2, where body width is typically most thin, and the superior femoral head or iliac crest (for scans that did not include the pelvis), where body width is typically most thick; method C averaged lateral measurements at these two levels from the CT projection scan, and method D averaged lateral and anteroposterior measurements at the same two levels from the axial CT images. Finally, we used body weight to characterize patient size, method E, and compared this with the various other measurement methods. Methods were compared across the entire population as well as by subgroup based on body width. Concordance correlation (ρ{sub c}) between each of the SSDE calculation methods (methods A-E) was greater than 0.92 across the entire population, although the range was wider when analyzed by subgroup (0.42-0.99). When we compared each SSDE measurement method with CTDI{sub vol,} there was poor correlation, ρ{sub c}<0.77, with percentage differences between 20.8% and 51.0%. Automated computer algorithms are accurate and efficient in the calculation of SSDE. Manual methods based on patient thickness provide

  3. The Comparison Study of Short-Term Prediction Methods to Enhance the Model Predictive Controller Applied to Microgrid Energy Management

    Directory of Open Access Journals (Sweden)

    César Hernández-Hernández

    2017-06-01

    Full Text Available Electricity load forecasting, optimal power system operation and energy management play key roles that can bring significant operational advantages to microgrids. This paper studies how methods based on time series and neural networks can be used to predict energy demand and production, allowing them to be combined with model predictive control. Comparisons of different prediction methods and different optimum energy distribution scenarios are provided, permitting us to determine when short-term energy prediction models should be used. The proposed prediction models in addition to the model predictive control strategy appear as a promising solution to energy management in microgrids. The controller has the task of performing the management of electricity purchase and sale to the power grid, maximizing the use of renewable energy sources and managing the use of the energy storage system. Simulations were performed with different weather conditions of solar irradiation. The obtained results are encouraging for future practical implementation.

  4. A Novel Group-Fused Sparse Partial Correlation Method for Simultaneous Estimation of Functional Networks in Group Comparison Studies.

    Science.gov (United States)

    Liang, Xiaoyun; Vaughan, David N; Connelly, Alan; Calamante, Fernando

    2018-05-01

    The conventional way to estimate functional networks is primarily based on Pearson correlation along with classic Fisher Z test. In general, networks are usually calculated at the individual-level and subsequently aggregated to obtain group-level networks. However, such estimated networks are inevitably affected by the inherent large inter-subject variability. A joint graphical model with Stability Selection (JGMSS) method was recently shown to effectively reduce inter-subject variability, mainly caused by confounding variations, by simultaneously estimating individual-level networks from a group. However, its benefits might be compromised when two groups are being compared, given that JGMSS is blinded to other groups when it is applied to estimate networks from a given group. We propose a novel method for robustly estimating networks from two groups by using group-fused multiple graphical-lasso combined with stability selection, named GMGLASS. Specifically, by simultaneously estimating similar within-group networks and between-group difference, it is possible to address inter-subject variability of estimated individual networks inherently related with existing methods such as Fisher Z test, and issues related to JGMSS ignoring between-group information in group comparisons. To evaluate the performance of GMGLASS in terms of a few key network metrics, as well as to compare with JGMSS and Fisher Z test, they are applied to both simulated and in vivo data. As a method aiming for group comparison studies, our study involves two groups for each case, i.e., normal control and patient groups; for in vivo data, we focus on a group of patients with right mesial temporal lobe epilepsy.

  5. Manual versus automatic bladder wall thickness measurements: a method comparison study

    NARCIS (Netherlands)

    Oelke, M.; Mamoulakis, C.; Ubbink, D.T.; de la Rosette, J.J.; Wijkstra, H.

    2009-01-01

    Purpose To compare repeatability and agreement of conventional ultrasound bladder wall thickness (BWT) measurements with automatically obtained BWT measurements by the BVM 6500 device. Methods Adult patients with lower urinary tract symptoms, urinary incontinence, or postvoid residual urine were

  6. Comparison of multivariate methods for studying the G×E interaction

    Directory of Open Access Journals (Sweden)

    Deoclécio Domingos Garbuglio

    2015-12-01

    Full Text Available The objective of this work was to evaluate three statistical multivariate methods for analyzing adaptability and environmental stratification simultaneously, using data from maize cultivars indicated for planting in the State of Paraná-Brazil. Under the FGGE and GGE methods, the genotypic effect adjusts the G×E interactions across environments, resulting in a high percentage of explanation associated with a smaller number of axes. Environmental stratification via the FGGE and GGE methods showed similar responses, while the AMMI method did not ensure grouping of environments. The adaptability analysis revealed low divergence patterns of the responses obtained through the three methods. Genotypes P30F35, P30F53, P30R50, P30K64 and AS 1570 showed high yields associated with general adaptability. The FGGE method allowed differences in yield responses in specific regions and the impact in locations belonging to the same environmental group (through rE to be associated with the level of the simple portion of the G×E interaction.

  7. Study of comparison between neutron activation analysis and the other analytical methods

    International Nuclear Information System (INIS)

    Nagatsuka, Sumiko

    1986-01-01

    The neutron activation analysis (NAA) is compared with other analytical methods based on various data. It is concluded that NAA is most frequently used for the analysis of NBS environmental standard samples. NAA is suitable for the analysis of trace elements contained in environmental samples since non-destructive quantitative determination can be carried out simultaneously for different elements. NAA and XRF are the only methods which can be used for analyzing oil samples. This also indicates the usefulness of non-destructive techniques. In any standard sample, NAA can achieve a high accuracy for more than 90 % of the elements contained. On the other hand, the accuracy varies depending on the type of sample in the case of the other analytical methods examined. Regarding the prescision, NAA for any standard sample is the smallest in the proportion of the number of elements determined with C.V. (coefficient of variation) of less than 10 % to the total number of elements contained. However, the total number of elements which can be determined by NAA with C.V. of less than 10 % is greater than that by any of the other four methods examined. It should be noticed that there are some elements which can be determined only by NAA. (Nogami, K.)

  8. Comparison study between traditional and finite element methods for slopes under heavy rainfall

    Directory of Open Access Journals (Sweden)

    M. Rabie

    2014-08-01

    Moreover, slope stability concerning rainfall and infiltration is analyzed. Specially, two kinds of infiltrations (saturated and unsaturated are considered. Many slopes become saturated during periods of intense rainfall or snowmelt, with the water table rising to the ground surface, and water flowing essentially parallel to the direction of the “slope” and “Influence” of the change in shear strength, density, pore-water pressure and seepage force in soil slices on the slope stability is explained. Finally, it is found that classical limit equilibrium methods are highly conservative compared to the finite element approach. For assessment the factor of safety for slope using the later technique, no assumption needs to be made in advance about the shape or location of the failure surface, slice side forces and their directions. This document outlines the capabilities of the finite element method in the analysis of slope stability problems.

  9. Comparison of floods non-stationarity detection methods: an Austrian case study

    Science.gov (United States)

    Salinas, Jose Luis; Viglione, Alberto; Blöschl, Günter

    2016-04-01

    Non-stationarities in flood regimes have a huge impact in any mid and long term flood management strategy. In particular the estimation of design floods is very sensitive to any kind of flood non-stationarity, as they should be linked to a return period, concept that can be ill defined in a non-stationary context. Therefore it is crucial when analyzing existent flood time series to detect and, where possible, attribute flood non-stationarities to changing hydroclimatic and land-use processes. This works presents the preliminary results of applying different non-stationarity detection methods on annual peak discharges time series over more than 400 gauging stations in Austria. The kind of non-stationarities analyzed include trends (linear and non-linear), breakpoints, clustering beyond stochastic randomness, and detection of flood rich/flood poor periods. Austria presents a large variety of landscapes, elevations and climates that allow us to interpret the spatial patterns obtained with the non-stationarity detection methods in terms of the dominant flood generation mechanisms.

  10. Direct comparison of phase-sensitive vibrational sum frequency generation with maximum entropy method: case study of water.

    Science.gov (United States)

    de Beer, Alex G F; Samson, Jean-Sebastièn; Hua, Wei; Huang, Zishuai; Chen, Xiangke; Allen, Heather C; Roke, Sylvie

    2011-12-14

    We present a direct comparison of phase sensitive sum-frequency generation experiments with phase reconstruction obtained by the maximum entropy method. We show that both methods lead to the same complex spectrum. Furthermore, we discuss the strengths and weaknesses of each of these methods, analyzing possible sources of experimental and analytical errors. A simulation program for maximum entropy phase reconstruction is available at: http://lbp.epfl.ch/. © 2011 American Institute of Physics

  11. Optimizing primary care research participation: a comparison of three recruitment methods in data-sharing studies.

    Science.gov (United States)

    Lord, Paul A; Willis, Thomas A; Carder, Paul; West, Robert M; Foy, Robbie

    2016-04-01

    Recruitment of representative samples in primary care research is essential to ensure high-quality, generalizable results. This is particularly important for research using routinely recorded patient data to examine the delivery of care. Yet little is known about how different recruitment strategies influence the characteristics of the practices included in research. We describe three approaches for recruiting practices to data-sharing studies, examining differences in recruitment levels and practice representativeness. We examined three studies that included varying populations of practices from West Yorkshire, UK. All used anonymized patient data to explore aspects of clinical practice. Recruitment strategies were 'opt-in', 'mixed opt-in and opt-out' and 'opt-out'. We compared aggregated practice data between recruited and not-recruited practices for practice list size, deprivation, chronic disease management, patient experience and rates of unplanned hospital admission. The opt-out strategy had the highest recruitment (80%), followed by mixed (70%) and opt-in (58%). Practices opting-in were larger (median 7153 versus 4722 patients, P = 0.03) than practices that declined to opt-in. Practices recruited by mixed approach were larger (median 7091 versus 5857 patients, P = 0.04) and had differences in the clinical quality measure (58.4% versus 53.9% of diabetic patients with HbA1c ≤ 59 mmol/mol, P Researchers should, with appropriate ethical safeguards, consider opt-out recruitment of practices for studies involving anonymized patient data sharing. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. A COMPARISON STUDY OF DIFFERENT MARKER SELECTION METHODS FOR SPECTRAL-SPATIAL CLASSIFICATION OF HYPERSPECTRAL IMAGES

    Directory of Open Access Journals (Sweden)

    D. Akbari

    2015-12-01

    Full Text Available An effective approach based on the Minimum Spanning Forest (MSF, grown from automatically selected markers using Support Vector Machines (SVM, has been proposed for spectral-spatial classification of hyperspectral images by Tarabalka et al. This paper aims at improving this approach by using image segmentation to integrate the spatial information into marker selection process. In this study, the markers are extracted from the classification maps, obtained by both SVM and segmentation algorithms, and then are used to build the MSF. The segmentation algorithms are the watershed, expectation maximization (EM and hierarchical clustering. These algorithms are used in parallel and independently to segment the image. Moreover, the pixels of each class, with the largest population in the classification map, are kept for each region of the segmentation map. Lastly, the most reliable classified pixels are chosen from among the exiting pixels as markers. Two benchmark urban hyperspectral datasets are used for evaluation: Washington DC Mall and Berlin. The results of our experiments indicate that, compared to the original MSF approach, the marker selection using segmentation algorithms leads in more accurate classification maps.

  13. Two Methods for Turning and Positioning and the Effect on Pressure Ulcer Development: A Comparison Cohort Study.

    Science.gov (United States)

    Powers, Jan

    2016-01-01

    We evaluated 2 methods for patient positioning on the development of pressure ulcers; specifically, standard of care (SOC) using pillows versus a patient positioning system (PPS). The study also compared turning effectiveness as well as nursing resources related to patient positioning and nursing injuries. A nonrandomized comparison design was used for the study. Sixty patients from a trauma/neurointensive care unit were included in the study. Patients were randomly assigned to 1 of 2 teams per standard bed placement practices at the institution. Patients were identified for enrollment in the study if they were immobile and mechanically ventilated with anticipation of 3 days or more on mechanical ventilation. Patients were excluded if they had a preexisting pressure ulcer. Patients were evaluated daily for the presence of pressure ulcers. Data were collected on the number of personnel required to turn patients. Once completed, the angle of the turn was measured. The occupational health database was reviewed to determine nurse injuries. The final sample size was 59 (SOC = 29; PPS = 30); there were no statistical differences between groups for age (P = .10), body mass index (P = .65), gender (P = .43), Braden Scale score (P = .46), or mobility score (P = .10). There was a statistically significant difference in the number of hospital-acquired pressure ulcers between turning methods (6 in the SOC group vs 1 in the PPS group; P = .042). The number of nurses needed for the SOC method was significantly higher than the PPS (P ≤ 0.001). The average turn angle achieved using the PPS was 31.03°, while the average turn angle achieved using SOC was 22.39°. The difference in turn angle from initial turn to 1 hour after turning in the SOC group was statistically significant (P patients to prevent development of pressure ulcers.

  14. A METHOD OF INTEGRATED ASSESSMENT OF LIVER FIBROSIS DEGREE: A COMPARISON OF THE OPTICAL METHOD FOR THE STUDY OF RED BLOOD CELLS AND INDIRECT ELASTOGRAPHY OF THE LIVER

    Directory of Open Access Journals (Sweden)

    M. V. Kruchinina

    2017-01-01

    Full Text Available The presented  method  of integrated  assessment of liver fibrosis degree based on the comparison of the data obtained in the study of electric and viscoelastic parameters of erythrocytes by the dielectrophoresis  method  using the electro-optical system  of the detection  cells and method  for indirect elastometry. A high degree of comparability of the results of the above-described  methods  was established  when the degree of fibrosis F 2-4  in the  absence  of marked  cytolysis, cholestasis,  inflammatory  syndrome,  metal  overload. It is shown that  parallel using the methods  of dielectrophoresis and indirect elastography is needed in the presence of a rise of transaminases, gammaglutamyltranspeptidase more than 5 norms, expressed dysproteinemia,  syndromes of iron overload, copper to increase the accuracy in determining the degree of liver fibrosis. The evaluation of dynamics of changes of the degree of fibrosis during antiviral therapy is more accurate by the method  of indirect elastometry, and the method of dielectrophoresis  is preferable in the treatment of nonalcoholic fatty liver disease. In cases of restrictions on the use of the method  for indirect elastography (marked obesity, ascites, cholelithiasis, pregnancy, presence of pacemaker, prosthesis to determine  the degree of fibrosis the method of dielectrophoresis  of red blood cells can be used. Simultaneous use of both methods  (using the identified discriminatory values allows to reduce or to neutralize their disadvantages, dependence on associated syndromes, to expand the possibilities of their application, to improve the diagnostic accuracy in determining each of the degrees of liver fibrosis. Integrated application of both methods — indirect elastography and dielectrophoresis of red blood cells — for determining the degree of liver fibrosis allows to achieve high levels of sensitivity (88.9 percent and specificity (100 percent compared to

  15. Study of n-γ discrimination by digital charge comparison method for a large volume liquid scintillator

    International Nuclear Information System (INIS)

    Moszynski, M.; Costa, G.J.; Guillaume, G.; Heusch, B.; Huck, A.; Ring, C.; Bizard, G.; Durand, D.; Peter, J.; Tamain, B.; El Masri, Y.; Hanappe, F.

    1992-01-01

    The study of the n-γ discrimination for a large 41 volume BC501A liquid scintillator coupled to a 130 mm diameter XP4512B photomultiplier was carried out by digital charge comparison method. A very good n-γ discrimination down to 100 keV of recoil electron energy was achieved. The measured relative intensity of the charge integrated at the slow component of the scintillation pulse and the photoelectron yield of the tested counter allow the factor of merit of the n-γ discrimination spectra to be calculated and to be compared with those measured experimentally. This shows that the main limitation of the n-γ discrimination is associated with the statistical fluctuation of the photoelectron number at the slow component. A serious effect of the distortion in the cable used to send the photomultiplier pulse to the electronics for the n-γ discrimination was studied. This suggests that the length of RG58 cable should be limited to about 40 m to preserve a high quality n-γ discrimination. (orig.)

  16. Measurement of Capsaicinoids in Chiltepin Hot Pepper: A Comparison Study between Spectrophotometric Method and High Performance Liquid Chromatography Analysis

    Directory of Open Access Journals (Sweden)

    Alberto González-Zamora

    2015-01-01

    Full Text Available Direct spectrophotometric determination of capsaicinoids content in Chiltepin pepper was investigated as a possible alternative to HPLC analysis. Capsaicinoids were extracted from Chiltepin in red ripe and green fruit with acetonitrile and evaluated quantitatively using the HPLC method with capsaicin and dihydrocapsaicin standards. Three samples of different treatment were analyzed for their capsaicinoids content successfully by these methods. HPLC-DAD revealed that capsaicin, dihydrocapsaicin, and nordihydrocapsaicin comprised up to 98% of total capsaicinoids detected. The absorbance of the diluted samples was read on a spectrophotometer at 215–300 nm and monitored at 280 nm. We report herein the comparison between traditional UV assays and HPLC-DAD methods for the determination of the molar absorptivity coefficient of capsaicin (ε280=3,410 and ε280=3,720 M−1 cm−1 and dihydrocapsaicin (ε280=4,175 and ε280=4,350 M−1 cm−1, respectively. Statistical comparisons were performed using the regression analyses (ordinary linear regression and Deming regression and Bland-Altman analysis. Comparative data for pungency was determined spectrophotometrically and by HPLC on samples ranging from 29.55 to 129 mg/g with a correlation of 0.91. These results indicate that the two methods significantly agree. The described spectrophotometric method can be routinely used for total capsaicinoids analysis and quality control in agricultural and pharmaceutical analysis.

  17. Assessment of interchangeability rate between 2 methods of measurements: An example with a cardiac output comparison study.

    Science.gov (United States)

    Lorne, Emmanuel; Diouf, Momar; de Wilde, Robert B P; Fischer, Marc-Olivier

    2018-02-01

    The Bland-Altman (BA) and percentage error (PE) methods have been previously described to assess the agreement between 2 methods of medical or laboratory measurements. This type of approach raises several problems: the BA methodology constitutes a subjective approach to interchangeability, whereas the PE approach does not take into account the distribution of values over a range. We describe a new methodology that defines an interchangeability rate between 2 methods of measurement and cutoff values that determine the range of interchangeable values. We used a simulated data and a previously published data set to demonstrate the concept of the method. The interchangeability rate of 5 different cardiac output (CO) pulse contour techniques (Wesseling method, LiDCO, PiCCO, Hemac method, and Modelflow) was calculated, in comparison with the reference pulmonary artery thermodilution CO using our new method. In our example, Modelflow with a good interchangeability rate of 93% and a cutoff value of 4.8 L min, was found to be interchangeable with the thermodilution method for >95% of measurements. Modelflow had a higher interchangeability rate compared to Hemac (93% vs 86%; P = .022) or other monitors (Wesseling cZ = 76%, LiDCO = 73%, and PiCCO = 62%; P < .0001). Simulated data and reanalysis of a data set comparing 5 CO monitors against thermodilution CO showed that, depending on the repeatability of the reference method, the interchangeability rate combined with a cutoff value could be used to define the range of values over which interchangeability remains acceptable.

  18. Comparison of gas dehydration methods based on energy ...

    African Journals Online (AJOL)

    Comparison of gas dehydration methods based on energy consumption. ... PROMOTING ACCESS TO AFRICAN RESEARCH ... This study compares three conventional methods of natural gas (Associated Natural Gas) dehydration to carry out ...

  19. Evaluation of analytical reconstruction with a new gap-filling method in comparison to iterative reconstruction in [11C]-raclopride PET studies

    International Nuclear Information System (INIS)

    Tuna, U.; Johansson, J.; Ruotsalainen, U.

    2014-01-01

    The aim of the study was (1) to evaluate the reconstruction strategies with dynamic [ 11 C]-raclopride human positron emission tomography (PET) studies acquired from ECAT high-resolution research tomograph (HRRT) scanner and (2) to justify for the selected gap-filling method for analytical reconstruction with simulated phantom data. A new transradial bicubic interpolation method has been implemented to enable faster analytical 3D-reprojection (3DRP) reconstructions for the ECAT HRRT PET scanner data. The transradial bicubic interpolation method was compared to the other gap-filling methods visually and quantitatively using the numerical Shepp-Logan phantom. The performance of the analytical 3DRP reconstruction method with this new gap-filling method was evaluated in comparison with the iterative statistical methods: ordinary Poisson ordered subsets expectation maximization (OPOSEM) and resolution modeled OPOSEM methods. The image reconstruction strategies were evaluated using human data at different count statistics and consequently at different noise levels. In the assessments, 14 [ 11 C]-raclopride dynamic PET studies (test-retest studies of 7 healthy subjects) acquired from the HRRT PET scanner were used. Besides the visual comparisons of the methods, we performed regional quantitative evaluations over the cerebellum, caudate and putamen structures. We compared the regional time-activity curves (TACs), areas under the TACs and binding potential (BP ND ) values. The results showed that the new gap-filling method preserves the linearity of the 3DRP method. Results with the 3DRP after gap-filling method exhibited hardly any dependency on the count statistics (noise levels) in the sinograms while we observed changes in the quantitative results with the EM-based methods for different noise contamination in the data. With this study, we showed that 3DRP with transradial bicubic gap-filling method is feasible for the reconstruction of high-resolution PET data with

  20. Sampling methods in archaeomagnetic dating: A comparison using case studies from Wörterberg, Eisenerz and Gams Valley (Austria)

    Science.gov (United States)

    Trapanese, A.; Batt, C. M.; Schnepp, E.

    The aim of this research was to review the relative merits of different methods of taking samples for archaeomagnetic dating. To allow different methods to be investigated, two archaeological structures and one modern fireplace were sampled in Austria. On each structure a variety of sampling methods were used: the tube and disc techniques of Clark et al. (Clark, A.J., Tarling, D.H., Noel, M., 1988. Developments in archaeomagnetic dating in Great Britain. Journal of Archaeological Science 15, 645-667), the drill core technique, the mould plastered hand block method of Thellier, and a modification of it. All samples were oriented with a magnetic compass and sun compass, where weather conditions allowed. Approximately 12 discs, tubes, drill cores or plaster hand blocks were collected from each structure, with one mould plaster hand block being collected and cut into specimens. The natural remanent magnetisation (NRM) of the samples was measured and stepwise alternating field (AF) or thermal demagnetisation was applied. Samples were measured either in the UK or in Austria, which allowed the comparison of results between magnetometers with different sensitivity. The tubes and plastered hand block specimens showed good agreement in directional results, and the samples obtained showed good stability. The discs proved to be unreliable as both NRM and the characteristic remanent magnetisation (ChRM) distribution were very scattered. The failure of some methods may be related to the suitability of the material sampled, for example if it was disturbed before sampling, had been insufficiently heated or did not contain appropriate magnetic minerals to retain a remanent magnetisation. Caution is also recommended for laboratory procedures as the cutting of poorly consolidated specimens may disturb the material and therefore the remanent magnetisation. Criteria and guidelines were established to aid researchers in selecting the most appropriate method for a particular

  1. A comparison of two methods of measuring static coefficient of friction at low normal forces: a pilot study.

    Science.gov (United States)

    Seo, Na Jin; Armstrong, Thomas J; Drinkaus, Philip

    2009-01-01

    This study compares two methods for estimating static friction coefficients for skin. In the first method, referred to as the 'tilt method', a hand supporting a flat object is tilted until the object slides. The friction coefficient is estimated as the tangent of the angle of the object at the slip. The second method estimates the friction coefficient as the pull force required to begin moving a flat object over the surface of the hand, divided by object weight. Both methods were used to estimate friction coefficients for 12 subjects and three materials (cardboard, aluminium, rubber) against a flat hand and against fingertips. No differences in static friction coefficients were found between the two methods, except for that of rubber, where friction coefficient was 11% greater for the tilt method. As with previous studies, the friction coefficients varied with contact force and contact area. Static friction coefficient data are needed for analysis and design of objects that are grasped or manipulated with the hand. The tilt method described in this study can easily be used by ergonomic practitioners to estimate static friction coefficients in the field in a timely manner.

  2. A Comparison of Case Study and Traditional Teaching Methods for Improvement of Oral Communication and Critical-Thinking Skills

    Science.gov (United States)

    Noblitt, Lynnette; Vance, Diane E.; Smith, Michelle L. DePoy

    2010-01-01

    This study compares a traditional paper presentation approach and a case study method for the development and improvement of oral communication skills and critical-thinking skills in a class of junior forensic science majors. A rubric for rating performance in these skills was designed on the basis of the oral communication competencies developed…

  3. Comparison of two down-scaling methods for climate study and climate change on the mountain areas in France

    International Nuclear Information System (INIS)

    Piazza, Marie; Page, Christian; Sanchez-Gomez, Emilia; Terray, Laurent; Deque, Michel

    2013-01-01

    Mountain regions are highly vulnerable to climate change and are likely to be among the areas most impacted by global warming. But climate projections for the end of the 21. century are developed with general circulation models of climate, which do not present a sufficient horizontal resolution to accurately evaluate the impacts of warming on these regions. Several techniques are then used to perform a spatial down-scaling (on the order of 10 km). There are two categories of down-scaling methods: dynamical methods that require significant computational resources for the achievement of regional climate simulations at high resolution, and statistical methods that require few resources but an observation dataset over a long period and of good quality. In this study, climate simulations of the global atmospheric model ARPEGE projections over France are down-scaled according to a dynamical method, performed with the ALADIN-Climate regional model, and a statistical method performed with the software DSClim developed at CERFACS. The two down-scaling methods are presented and the results on the climate of the French mountains are evaluated for the current climate. Both methods give similar results for average snowfall. However extreme events of total precipitation (droughts, intense precipitation events) are largely underestimated by the statistical method. Then, the results of both methods are compared for two future climate projections, according to the greenhouse gas emissions scenario A1B of IPCC. The two methods agree on fewer frost days, a significant decrease in the amounts of solid precipitation and an average increase in the percentage of dry days of more than 10%. The results obtained on Corsica are more heterogeneous but they are questionable because the reduced spatial domain is probably not very relevant regarding statistical sampling. (authors)

  4. Comparison of analytical methods used to measure petroleum hydrocarbons in soils and their application to bioremediation studies

    International Nuclear Information System (INIS)

    Douglas, G.S.; Wong, W.M.; Rigatti, M.J.; McMillen, S.J.

    1995-01-01

    Chemical measurements provide a means to evaluate crude oil and refined product bioremediation effectiveness in field and laboratory studies. These measurements are used to determine the net decrease in product or target compound concentrations in complex soil systems. The analytical methods used to evaluate these constituents will have a direct impact on the ability of the investigator to; (1) detect losses due to biodegradation, (2) understand the processes responsible for the hydrocarbon degradation and, (3) determine the rates of hydrocarbon degradation. This understanding is critical for the testing and design of bioremediation programs. While standard EPA methods are useful for measuring a wide variety of industrial and agrochemicals, they were not designed for the detection and accurate measurement of petroleum compounds. The chemical data generated with these standard methods are usually of limited utility because they lack the chemical specificity required to evaluate hydrocarbon compositional changes in the oil contamination required to evaluate biodegradation. The applications and limitations of standard EPA methodologies (EPA Methods 418.1, 8270, and modified 8015) will be evaluated and compared to several new analytical methods currently being used by the petroleum industry (e.g., gross compositional analysis, TLC-FID analysis, and enhanced EPA Method 8270) to evaluate bioremediation effectiveness in soils

  5. Comparison of modern and traditional methods of soilsorption complex measurement : the basis of long -term studies and modelling

    Directory of Open Access Journals (Sweden)

    Kučera Aleš

    2014-03-01

    Full Text Available This paper presents the correlations between two different analytical methods of assessing soil nutrient contents. Soil nutrient content measurements measured using the flame atomic absorption spectrometry (FAAS method, which uses barium chloride extraction, were compared with those of the now-unused Gedroiz method, which uses ammonium chloride extraction (calcium by titration, magnesium, potassium and sodium by weighing. Natural forest soils from the Ukrainian Carpathians at the localities of Javorník and Pop Ivan were used. Despite the risk of analysis errors during the complicated analytical procedure, the results showed a high level of correlation between different nutrient content measurements across the whole soil profile. This allows concentration values given in different studies to be linearly recalculated on results of modern method. In this way, results can be used to study soil’s chemical changes over time from the soil samples that were analysed in the past using labour-intensive and time-consuming methods with a higher risk of analytic error.

  6. Randomly and Non-Randomly Missing Renal Function Data in the Strong Heart Study: A Comparison of Imputation Methods.

    Directory of Open Access Journals (Sweden)

    Nawar Shara

    Full Text Available Kidney and cardiovascular disease are widespread among populations with high prevalence of diabetes, such as American Indians participating in the Strong Heart Study (SHS. Studying these conditions simultaneously in longitudinal studies is challenging, because the morbidity and mortality associated with these diseases result in missing data, and these data are likely not missing at random. When such data are merely excluded, study findings may be compromised. In this article, a subset of 2264 participants with complete renal function data from Strong Heart Exams 1 (1989-1991, 2 (1993-1995, and 3 (1998-1999 was used to examine the performance of five methods used to impute missing data: listwise deletion, mean of serial measures, adjacent value, multiple imputation, and pattern-mixture. Three missing at random models and one non-missing at random model were used to compare the performance of the imputation techniques on randomly and non-randomly missing data. The pattern-mixture method was found to perform best for imputing renal function data that were not missing at random. Determining whether data are missing at random or not can help in choosing the imputation method that will provide the most accurate results.

  7. A global multicenter study on reference values: 1. Assessment of methods for derivation and comparison of reference intervals.

    Science.gov (United States)

    Ichihara, Kiyoshi; Ozarda, Yesim; Barth, Julian H; Klee, George; Qiu, Ling; Erasmus, Rajiv; Borai, Anwar; Evgina, Svetlana; Ashavaid, Tester; Khan, Dilshad; Schreier, Laura; Rolle, Reynan; Shimizu, Yoshihisa; Kimura, Shogo; Kawano, Reo; Armbruster, David; Mori, Kazuo; Yadav, Binod K

    2017-04-01

    The IFCC Committee on Reference Intervals and Decision Limits coordinated a global multicenter study on reference values (RVs) to explore rational and harmonizable procedures for derivation of reference intervals (RIs) and investigate the feasibility of sharing RIs through evaluation of sources of variation of RVs on a global scale. For the common protocol, rather lenient criteria for reference individuals were adopted to facilitate harmonized recruitment with planned use of the latent abnormal values exclusion (LAVE) method. As of July 2015, 12 countries had completed their study with total recruitment of 13,386 healthy adults. 25 analytes were measured chemically and 25 immunologically. A serum panel with assigned values was measured by all laboratories. RIs were derived by parametric and nonparametric methods. The effect of LAVE methods is prominent in analytes which reflect nutritional status, inflammation and muscular exertion, indicating that inappropriate results are frequent in any country. The validity of the parametric method was confirmed by the presence of analyte-specific distribution patterns and successful Gaussian transformation using the modified Box-Cox formula in all countries. After successful alignment of RVs based on the panel test results, nearly half the analytes showed variable degrees of between-country differences. This finding, however, requires confirmation after adjusting for BMI and other sources of variation. The results are reported in the second part of this paper. The collaborative study enabled us to evaluate rational methods for deriving RIs and comparing the RVs based on real-world datasets obtained in a harmonized manner. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  8. A comparison between the conventional manual ROI method and an automatic algorithm for semiquantitative analysis of SPECT studies

    International Nuclear Information System (INIS)

    Pagan, L; Novi, B; Guidarelli, G; Tranfaglia, C; Galli, S; Lucchi, G; Fagioli, G

    2011-01-01

    In this study, the performance of a free software for automatic segmentation of striatal SPECT brain studies (BasGanV2 - www.aimn.it) and a standard manual Region Of Interest (ROI) method were compared. The anthropomorphic Alderson RSD phantom, filled with solutions at different concentration of 123 I-FP-CIT with Caudate-Putamen to Background ratios between 1 and 8.7 and Caudate to Putamen ratios between 1 and 2, was imaged on a Philips-Irix triple head gamma camera. Images were reconstructed using filtered back-projection and processed with both BasGanV2, that provides normalized striatal uptake values on volumetric anatomical ROIs, and a manual method, based on average counts per voxel in ROIs drawn in a three-slice section. Caudate-Putamen/Background and Caudate/Putamen ratios obtained with the two methods were compared with true experimental ratios. Good correlation was found for each method; BasGanV2, however, has higher R index (BasGan R mean = 0.95, p mean = 0.89, p 123 I-FP-CIT SPECT data with, moreover, the advantage of the availability of a control subject's database.

  9. Cerebral perfusion studies using Au-195: Investigations into their clinical usefulness and comparisons with the xenon-133 inhalation method

    International Nuclear Information System (INIS)

    Draws, J.

    1989-01-01

    Au-195m cerebral perfusion studies in the diagnosis of blood supply disorders of the brain have only recently leaped into currency. Au-195m is not capable of diffusing. This particular property permits first-pass times of vascular transfer to be determined for cerebral tissues that correlate with the degree of cerebral circulation. In the study described here, attempts were made to shed more light on the clinical usefulness of the method. For this purpose, the record sheets of two cohorts of patients were analysed on a retrospective basis. 1. In 23 patients, where the cerebrovascular disorders were strictly confined to the cerebral hemispheres, the blood supply of the brain was examined on the basis of both Au-195m cerebral perfusion studies and the xenon-133 inhalation method. In the evaluation of the findings based on the Au-195m study the investigator was blinded to the neurological manifestations of the disease and the results from other studies. In 82% of the patients the perfusion mapping using Au-195m was consistent with the clinical symptoms. 2. In a second group of patients, the probable results of the Au-195m perfusion study were forecasted on the basis of the medical history, clinical symptoms and preliminary diagnosis and subsequently compared to those actually obtained. Expected and actual results were found to be in agreement for 88% of cases. The results provided evidence of the suitability of Au-195m cerebral perfusion studies to examine the blood suply of the brain. In view of the fact that the examinations and measurements are relatively uncomplicated, this newly developed method is most likely to be used on a broader basis in the future. (orig./MG) [de

  10. Comparison of fatigue accumulated during and after prolonged robotic and laparoscopic surgical methods: a cross-sectional study.

    Science.gov (United States)

    González-Sánchez, Manuel; González-Poveda, Ivan; Mera-Velasco, Santiago; Cuesta-Vargas, Antonio I

    2017-03-01

    The aim of the present study was to analyse the fatigue experienced by surgeons during and after performing robotic and laparoscopic surgery and to analyse muscle function, self-perceived fatigue and postural balance. Cross-sectional study considering two surgical protocols (laparoscopic and robotic) with two different roles (chief and assistant surgeon). Fatigue was recorded in two ways: pre- and post-surgery using questionnaires [Profile of Mood States (POMS), Quick Questionnaire Piper Fatigue Scale and Visual Analogue Scale (VAS)-related fatigue] and parametrising functional tests [handgrip and single-leg balance test (SLBT)] and during the intervention by measuring the muscle activation of eight different muscles via surface electromyography and kinematic measurement (using inertial sensors). Each surgery profile intervention (robotic/laparoscopy-chief/assistant surgeon) was measured three times, totalling 12 measured surgery interventions. The minimal duration of surgery was 180 min. Pre- and post-surgery, all questionnaires showed that the magnitude of change was higher for the chief surgeon compared with the assistant surgeon, with differences of between 10 % POMS and 16.25 % VAS (robotic protocol) and between 3.1 % POMS and 12.5 % VAS (laparoscopic protocol). In the inter-profile comparison, the chief surgeon (robotic protocol) showed a lower balance capacity during the SLBT after surgery. During the intervention, the kinematic variables showed significant differences between the chief and assistant surgeon in the robotic protocol, but not in the laparoscopic protocol. Regarding muscle activation, there was not enough muscle activity to generate fatigue. Prolonged surgery increased fatigue in the surgeon; however, the magnitude of fatigue differed between surgical profiles. The surgeon who experienced the greatest fatigue was the chief surgeon in the robotic protocol.

  11. Comparison of gating methods for the real-time analysis of left ventricular function in nonimaging blood pool studies.

    Science.gov (United States)

    Beard, B B; Stewart, J R; Shiavi, R G; Lorenz, C H

    1995-01-01

    Gating methods developed for electrocardiographic-triggered radionuclide ventriculography are being used with nonimaging detectors. These methods have not been compared on the basis of their real-time performance or suitability for determination of load-independent indexes of left ventricular function. This work evaluated the relative merits of different gating methods for nonimaging radionuclude ventriculographic studies, with particular emphasis on their suitability for real-time measurements and the determination of pressure-volume loops. A computer model was used to investigate the relative accuracy of forward gating, backward gating, and phase-mode gating. The durations of simulated left ventricular time-activity curves were randomly varied. Three acquisition parameters were considered: frame rate, acceptance window, and sample size. Twenty-five studies were performed for each combination of acquisition parameters. Hemodynamic and shape parameters from each study were compared with reference parameters derived directly from the random time-activity curves. Backward gating produced the largest errors under all conditions. For both forward gating and phase-mode gating, ejection fraction was underestimated and time to end systole and normalized peak ejection rate were overestimated. For the hemodynamic parameters, forward gating was marginally superior to phase-mode gating. The mean difference in errors between forward and phase-mode gating was 1.47% (SD 2.78%). However, for root mean square shape error, forward gating was several times worse in every case and seven times worse than phase-mode gating on average. Both forward and phase-mode gating are suitable for real-time hemodynamic measurements by nonimaging techniques. The small statistical difference between the methods is not clinically significant. The true shape of the time-activity curve is maintained most accurately by phase-mode gating.

  12. Age modelling for Pleistocene lake sediments: A comparison of methods from the Andean Fúquene Basin (Colombia) case study

    NARCIS (Netherlands)

    Groot, M.H.M.; van der Plicht, J.; Hooghiemstra, H.; Lourens, L.J.; Rowe, H.D.

    2014-01-01

    Challenges and pitfalls for developing age models for long lacustrine sedimentary records are discussed and a comparison is made between radiocarbon dating, visual curve matching, and frequency analysis in the depth domain in combination with cyclostratigraphy. A core section of the high resolution

  13. Age modelling for Pleistocene lake sediments: a comparison of methods from the Andean Fúquene Basin (Colombia) case study

    NARCIS (Netherlands)

    Groot, M.H.M.; van der Plicht, J.; Hooghiemstra, H.; Lourens, L.J.; Rowe, H.D.

    2014-01-01

    Challenges and pitfalls for developing age models for long lacustrine sedimentary records are discussed and a comparison is made between radiocarbon dating, visual curve matching, and frequency analysis in the depth domain in combination with cyclostratigraphy. A core section of the high resolution

  14. Statistical methods for conducting agreement (comparison of clinical tests) and precision (repeatability or reproducibility) studies in optometry and ophthalmology.

    Science.gov (United States)

    McAlinden, Colm; Khadka, Jyoti; Pesudovs, Konrad

    2011-07-01

    The ever-expanding choice of ocular metrology and imaging equipment has driven research into the validity of their measurements. Consequently, studies of the agreement between two instruments or clinical tests have proliferated in the ophthalmic literature. It is important that researchers apply the appropriate statistical tests in agreement studies. Correlation coefficients are hazardous and should be avoided. The 'limits of agreement' method originally proposed by Altman and Bland in 1983 is the statistical procedure of choice. Its step-by-step use and practical considerations in relation to optometry and ophthalmology are detailed in addition to sample size considerations and statistical approaches to precision (repeatability or reproducibility) estimates. Ophthalmic & Physiological Optics © 2011 The College of Optometrists.

  15. A comparison study of Agrobacterium-mediated transformation methods for root-specific promoter analysis in soybean.

    Science.gov (United States)

    Li, Caifeng; Zhang, Haiyan; Wang, Xiurong; Liao, Hong

    2014-11-01

    Both in vitro and in vivo hairy root transformation systems could not replace whole plant transformation for promoter analysis of root-specific and low-P induced genes in soybean. An efficient genetic transformation system is crucial for promoter analysis in plants. Agrobacterium-mediated transformation is the most popular method to produce transgenic hairy roots or plants. In the present study, first, we compared the two different Agrobacterium rhizogenes-mediated hairy root transformation methods using either constitutive CaMV35S or the promoters of root-preferential genes, GmEXPB2 and GmPAP21, in soybean, and found the efficiency of in vitro hairy root transformation was significantly higher than that of in vivo transformation. We compared Agrobacterium rhizogenes-mediated hairy root and Agrobacterium tumefaciens-mediated whole plant transformation systems. The results showed that low-phosphorous (P) inducible GmEXPB2 and GmPAP21 promoters could not induce the increased expression of the GUS reporter gene under low P stress in both in vivo and in vitro transgenic hairy roots. Conversely, GUS activity of GmPAP21 promoter was significantly higher at low P than high P in whole plant transformation. Therefore, both in vitro and in vivo hairy root transformation systems could not replace whole plant transformation for promoter analysis of root-specific and low-P induced genes in soybean.

  16. Prospective Study on Noninvasive Assessment of Intracranial Pressure in Traumatic Brain-Injured Patients: Comparison of Four Methods.

    Science.gov (United States)

    Cardim, Danilo; Robba, Chiara; Donnelly, Joseph; Bohdanowicz, Michal; Schmidt, Bernhard; Damian, Maxwell; Varsos, Georgios V; Liu, Xiuyun; Cabeleira, Manuel; Frigieri, Gustavo; Cabella, Brenno; Smielewski, Peter; Mascarenhas, Sergio; Czosnyka, Marek

    2016-04-15

    Elevation of intracranial pressure (ICP) may occur in many diseases, and therefore the ability to measure it noninvasively would be useful. Flow velocity signals from transcranial Doppler (TCD) have been used to estimate ICP; however, the relative accuracy of these methods is unclear. This study aimed to compare four previously described TCD-based methods with directly measured ICP in a prospective cohort of traumatic brain-injured patients. Noninvasive ICP (nICP) was obtained using the following methods: 1) a mathematical "black-box" model based on interaction between TCD and arterial blood pressure (nICP_BB); 2) based on diastolic flow velocity (nICP_FVd); 3) based on critical closing pressure (nICP_CrCP); and 4) based on TCD-derived pulsatility index (nICP_PI). In time domain, for recordings including spontaneous changes in ICP greater than 7 mm Hg, nICP_PI showed the best correlation with measured ICP (R = 0.61). Considering every TCD recording as an independent event, nICP_BB generally showed to be the best estimator of measured ICP (R = 0.39; p area under the curve [AUC] = 0.66; p AUC (0.70; p AUC = 0.64; p > 0.05). nICP_PI was not related to measured ICP using any of the above statistical indicators. We also introduced a new estimator (nICP_Av) based on the average of three methods (nICP_BB, nICP_FVd, and nICP_CrCP), which overall presented improved statistical indicators (R = 0.47; p AUC = 0.73; p < 0.05). nICP_PI appeared to reflect changes in ICP in time most accurately. nICP_BB was the best estimator for ICP "as a number." nICP_Av demonstrated to improve the accuracy of measured ICP estimation.

  17. Ongoing challenges to finding people with Parkinson's disease for epidemiological studies: a comparison of population-level case ascertainment methods.

    Science.gov (United States)

    Harris, M Anne; Koehoorn, Mieke; Teschke, Kay

    2011-07-01

    Locating Parkinson's disease cases for epidemiological studies has long been challenging. Self reports, secondary records of physician diagnosis and drug tracer methods each exhibit known disadvantages but have rarely been compared directly. Prescriptions of levodopa have in some studies been considered to comprise a reasonable proxy for Parkinson's disease diagnosis. We tested this assumption by comparing three methods of population-level case ascertainment. We compared the number of Parkinson's disease cases in British Columbia derived from self-reports in the 2001 Canadian Community Health Survey to those obtained from administrative records of filled levodopa prescriptions and to Parkinson's disease diagnoses from physician visit billing and hospital discharge records in 1996 and 2005. We directly compared a case definition based on levodopa prescriptions with a definition based on records of physician diagnosis by calculating positive predictive value and sensitivity. Crude prevalence estimates ranged from approximately 100 to 200 per 100,000. Levodopa-based case definitions overestimated prevalence, while physician- and hospital-record-based case definitions provided lower prevalence estimates compared to survey derived estimates. The proportion of levodopa users with a diagnosis of Parkinson's disease declined from 62% to 52% between 1996 and 2005. This decrease was most dramatic among women (64%-44%) and those under age 65 (54%-39%). Sex and age trends suggest increasing use of levodopa among patients with conditions other than Parkinson's disease, such as restless legs syndrome. Increased non-Parkinson's levodopa use decreases the efficiency of levodopa as a Parkinson's disease case tracer. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Comparison of Nested-PCR technique and culture method in ...

    African Journals Online (AJOL)

    USER

    2010-04-05

    Apr 5, 2010 ... Full Length Research Paper. Comparison of ... The aim of the present study was to evaluate the diagnostic value of nested PCR in genitourinary ... method. Based on obtained results, the positivity rate of urine samples in this study was 5.0% by using culture and PCR methods and 2.5% for acid fast staining.

  19. Comparison Re-invented: Adaptation of Universal Methods to African Studies (Conference Report Die Wiederentdeckung des Vergleichs: Zur Anwendung universeller Methoden in der Afrikaforschung (Konferenzbericht

    Directory of Open Access Journals (Sweden)

    Franzisca Zanker

    2013-01-01

    Full Text Available Drawing from a combination of specific, empirical research projects with different theoretical backgrounds, a workshop discussed one methodological aspect often somewhat overlooked in African Studies: comparison. Participants addressed several questions, along with presenting overviews of how different disciplines within African Studies approach comparison in their research and naming specific challenges within individual research projects. The questions examined included: Why is explicit comparative research so rare in African Studies? Is comparative research more difficult in the African context than in other regions? Does it benefit our research? Should scholars strive to generalise beyond individual cases? Do studies in our field require an explicit comparative design, or will implicit comparison suffice? Cross-discipline communication should help us to move forward in this methodological debate, though in the end the subject matter and specific research question will lead to the appropriate comparative approach, not the other way round.Mit Blick auf einige empirische Forschungsprojekte mit jeweils unterschiedlichem theoretischem Hintergrund wurde im Rahmen eines Workshops ein methodologischer Aspekt debattiert, der in der Afrikaforschung wenig Beachtung erfährt: der Vergleich. Die Teilnehmer(innen entwickelten Fragestellungen, stellten jeweils dar, inwieweit in den verschiedene Disziplinen der Afrikaforschung der Vergleich als Methode eingesetzt wird, und benannten spezifische Herausforderungen in diesem Zusammenhang für einzelne Forschungsprojekte. Unter anderem wurden folgende Fragen erörtert: Warum ist die explizit vergleichende Methode in der Afrikaforschung so selten? Ist vergleichende Forschung im Kontext Afrikas schwieriger anwendbar als in der Forschung zu anderen Regionen? Verbessert sie unsere Forschungsresultate? Sollten sich Forscher um Generalisierungen jenseits der Einzelfallstudien bemühen? Ist in der Afrikaforschung eine

  20. Comparison of equivalent linear and non linear methods on ground response analysis: case study at West Bangka site

    International Nuclear Information System (INIS)

    Eko Rudi Iswanto; Eric Yee

    2016-01-01

    Within the framework of identifying NPP sites, site surveys are performed in West Bangka (WB), Bangka-Belitung Island Province. Ground response analysis of a potential site has been carried out using peak strain profiles and peak ground acceleration. The objective of this research is to compare Equivalent Linear (EQL) and Non Linear (NL) methods of ground response analysis on the selected NPP site (West Bangka) using Deep Soil software. Equivalent linear method is widely used because requires soil data in simple way and short time of computational process. On the other hand, non linear method is capable of representing the actual soil behaviour by considering non linear soil parameter. The results showed that EQL method has similar trends to NL method. At surface layer, the acceleration values for EQL and NL methods are resulted as 0.425 g and 0.375 g respectively. NL method is more reliable in capturing higher frequencies of spectral acceleration compared to EQL method. (author)

  1. Correction for tissue attenuation in radionuclide gastric emptying studies: a comparison of a lateral image method and a geometric mean method

    Energy Technology Data Exchange (ETDEWEB)

    Collins, P.J.; Chatterton, B.E. (Royal Adelaide Hospital (Australia)); Horowitz, M.; Shearman, D.J.C. (Adelaide Univ. (Australia). Dept. of Medicine)

    1984-08-01

    Variation in depth of radionuclide within the stomach may result in significant errors in the measurement of gastric emptying if no attempt is made to correct for gamma-ray attenuation by the patient's tissues. A method of attenuation correction, which uses a single posteriorly located scintillation camera and correction factors derived from a lateral image of the stomach, was compared with a two-camera geometric mean method, in phantom studies and in five volunteer subjects. A meal of 100 g of ground beef containing /sup 99/Tcsup(m)-chicken liver, and 150 ml of water was used in the in vivo studies. In all subjects the geometric mean data showed that solid food emptied in two phases: an initial lag period, followed by a linear emptying phase. Using the geometric mean data as a standard, the anterior camera overestimated the 50% emptying time (T/sub 50/) by an average of 15% (range 5-18) and the posterior camera underestimated this parameter by 15% (4-22). The posterior data, corrected for attenuation using the lateral image method, underestimated the T/sub 50/ by 2% (-7 to +7). The difference in the distances of the proximal and distal stomach from the posterior detector was large in all subjects (mean 5.7 cm, range 3.9-7.4).

  2. Comparison of Nutrigenomics Technology Interface Tools for Consumers and Health Professionals: Protocol for a Mixed-Methods Study.

    Science.gov (United States)

    Littlejohn, Paula; Cop, Irene; Brown, Erin; Afroze, Rimi; Davison, Karen M

    2018-06-11

    Although nutrition interventions are a widely accepted resource for the prevention of long-term health conditions, current approaches have not adequately reduced chronic disease morbidity. Nutrigenomics has great potential; however, it is complicated to implement. There is a need for products based on nutrition-related gene test results that are easily understood, accessible, and used. The primary objective of this study was to compare a nonpractitioner-assisted direct-to-consumer self-driven approach to nutrigenomics versus an integrated and personalized practitioner-led method. This 4-month study used a mixed-methods design that included (1) a phase 1 randomized controlled trial that examined the effectiveness of a multifaceted, nutrition-based gene test (components assessed included major nutrients, food tolerances, food taste and preferences, and micronutrients) in changing health behaviors, followed by (2) a qualitative investigation that explored participants' experiences. The study recruited 55 healthy males and females (aged 35-55 years) randomized as a 2:1 ratio where 36 received the intervention (gene test results plus integrated and personalized nutrition report) and 19 were assigned to the control group (gene test results report emailed). The primary outcomes of interest measures included changes in diet (nutrients, healthy eating index), changes in measures on General Self-efficacy and Health-Related Quality of Life scales, and anthropometrics (body mass index, waist-to-hip ratio) measured at baseline, post intervention (3 and 6 weeks), and the final visit (week 9 post intervention). Of the 478 individuals who expressed interest, 180 were invited (37.7%, 180/478) and completed the eligibility screening questionnaire; 73 of the 180 invited individuals (40.5%) were deemed eligible. Of the 73 individuals who were deemed to be eligible, 58 completed the baseline health questionnaire and food records (79%). Of these 58 individuals, 3 were excluded either

  3. A comparison of interface tracking methods

    International Nuclear Information System (INIS)

    Kothe, D.B.; Rider, W.J.

    1995-01-01

    In this Paper we provide a direct comparison of several important algorithms designed to track fluid interfaces. In the process we propose improved criteria by which these methods are to be judged. We compare and contrast the behavior of the following interface tracking methods: high order monotone capturing schemes, level set methods, volume-of-fluid (VOF) methods, and particle-based (particle-in-cell, or PIC) methods. We compare these methods by first applying a set of standard test problems, then by applying a new set of enhanced problems designed to expose the limitations and weaknesses of each method. We find that the properties of these methods are not adequately assessed until they axe tested with flows having spatial and temporal vorticity gradients. Our results indicate that the particle-based methods are easily the most accurate of those tested. Their practical use, however, is often hampered by their memory and CPU requirements. Particle-based methods employing particles only along interfaces also have difficulty dealing with gross topology changes. Full PIC methods, on the other hand, do not in general have topology restrictions. Following the particle-based methods are VOF volume tracking methods, which are reasonably accurate, physically based, robust, low in cost, and relatively easy to implement. Recent enhancements to the VOF methods using multidimensional interface reconstruction and improved advection provide excellent results on a wide range of test problems

  4. Comparison study of exhaust plume impingement effects of small mono- and bipropellant thrusters using parallelized DSMC method.

    Directory of Open Access Journals (Sweden)

    Kyun Ho Lee

    Full Text Available A space propulsion system is important for the normal mission operations of a spacecraft by adjusting its attitude and maneuver. Generally, a mono- and a bipropellant thruster have been mainly used for low thrust liquid rocket engines. But as the plume gas expelled from these small thrusters diffuses freely in a vacuum space along all directions, unwanted effects due to the plume collision onto the spacecraft surfaces can dramatically cause a deterioration of the function and performance of a spacecraft. Thus, aim of the present study is to investigate and compare the major differences of the plume gas impingement effects quantitatively between the small mono- and bipropellant thrusters using the computational fluid dynamics (CFD. For an efficiency of the numerical calculations, the whole calculation domain is divided into two different flow regimes depending on the flow characteristics, and then Navier-Stokes equations and parallelized Direct Simulation Monte Carlo (DSMC method are adopted for each flow regime. From the present analysis, thermal and mass influences of the plume gas impingements on the spacecraft were analyzed for the mono- and the bipropellant thrusters. As a result, it is concluded that a careful understanding on the plume impingement effects depending on the chemical characteristics of different propellants are necessary for the efficient design of the spacecraft.

  5. Structural equation and log-linear modeling: a comparison of methods in the analysis of a study on caregivers' health

    Directory of Open Access Journals (Sweden)

    Rosenbaum Peter L

    2006-10-01

    Full Text Available Abstract Background In this paper we compare the results in an analysis of determinants of caregivers' health derived from two approaches, a structural equation model and a log-linear model, using the same data set. Methods The data were collected from a cross-sectional population-based sample of 468 families in Ontario, Canada who had a child with cerebral palsy (CP. The self-completed questionnaires and the home-based interviews used in this study included scales reflecting socio-economic status, child and caregiver characteristics, and the physical and psychological well-being of the caregivers. Both analytic models were used to evaluate the relationships between child behaviour, caregiving demands, coping factors, and the well-being of primary caregivers of children with CP. Results The results were compared, together with an assessment of the positive and negative aspects of each approach, including their practical and conceptual implications. Conclusion No important differences were found in the substantive conclusions of the two analyses. The broad confirmation of the Structural Equation Modeling (SEM results by the Log-linear Modeling (LLM provided some reassurance that the SEM had been adequately specified, and that it broadly fitted the data.

  6. Comparison of two occurrence risk assessment methods for collapse gully erosion ——A case study in Guangdong province

    Science.gov (United States)

    Sun, K.; Cheng, D. B.; He, J. J.; Zhao, Y. L.

    2018-02-01

    Collapse gully erosion is a specific type of soil erosion in the red soil region of southern China, and early warning and prevention of the occurrence of collapse gully erosion is very important. Based on the idea of risk assessment, this research, taking Guangdong province as an example, adopt the information acquisition analysis and the logistic regression analysis, to discuss the feasibility for collapse gully erosion risk assessment in regional scale, and compare the applicability of the different risk assessment methods. The results show that in the Guangdong province, the risk degree of collapse gully erosion occurrence is high in northeastern and western area, and relatively low in southwestern and central part. The comparing analysis of the different risk assessment methods on collapse gully also indicated that the risk distribution patterns from the different methods were basically consistent. However, the accuracy of risk map from the information acquisition analysis method was slightly better than that from the logistic regression analysis method.

  7. Voxel based statistical analysis method for microPET studies to assess the cerebral glucose metabolism in cat deafness model: comparison to ROI based method

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Su; Lee, Jae Sung; Park, Min Hyun; Lee, Jong Jin; Kang, Hye Jin; Lee, Hyo Jeong; Oh, Seung Ha; Kim, Chong Sun; Jung, June Key; Lee, Myung Chul; Lee, Dong Soo [Seoul National University College of Medicine, Seoul (Korea, Republic of); Lim, Sang Moo [KIRAMS, Seoul (Korea, Republic of)

    2005-07-01

    Imaging research on the brain of sensory-deprived cats using small animal PET scanner has gained interest since the abundant information about the sensory system of ths animal is available and close examination of the brain is possible due to larger size of its brain than mouse or rat. In this study, we have established the procedures for 3D voxel-based statistical analysis (SPM) of FDG PET image of cat brain, and confirmed using ROI based-method. FDG PET scans of 4 normal and 4 deaf cats were acquired for 30 minutes using microPET R4 scanner. Only the brain cortices were extracted using a masking and threshold method to facilitate spatial normalization. After spatial normalization and smoothing, 3D voxel-wise and ROI based t-test were performed to identify the regions with significant different FDG uptake between the normal and deaf cats. In ROI analysis, 26 ROIs were drawn on both hemispheres, and regional mean pixel value in each ROI was normalized to the global mean of the brain. Cat brains were spatially normalized well onto the target brain due to the removal of background activity. When cerebral glucose metabolism of deaf cats were compared to the normal controls after removing the effects of the global count, the glucose metabolism in the auditory cortex, head of caudate nucleus, and thalamus in both hemispheres of the deaf cats was significantly lower than that of the controls (P<0.01). No area showed a significantly increased metabolism in the deaf cats even in higher significance level (P<0.05). ROI analysis also showed significant reduction of glucose metabolism in the same region. This study established and confirmed a method for voxel-based analysis of animal PET data of cat brain, which showed high localization accuracy and specificity and was useful for examining the cerebral glucose metabolism in a cat cortical deafness model.

  8. Voxel based statistical analysis method for microPET studies to assess the cerebral glucose metabolism in cat deafness model: comparison to ROI based method

    International Nuclear Information System (INIS)

    Kim, Jin Su; Lee, Jae Sung; Park, Min Hyun; Lee, Jong Jin; Kang, Hye Jin; Lee, Hyo Jeong; Oh, Seung Ha; Kim, Chong Sun; Jung, June Key; Lee, Myung Chul; Lee, Dong Soo; Lim, Sang Moo

    2005-01-01

    Imaging research on the brain of sensory-deprived cats using small animal PET scanner has gained interest since the abundant information about the sensory system of ths animal is available and close examination of the brain is possible due to larger size of its brain than mouse or rat. In this study, we have established the procedures for 3D voxel-based statistical analysis (SPM) of FDG PET image of cat brain, and confirmed using ROI based-method. FDG PET scans of 4 normal and 4 deaf cats were acquired for 30 minutes using microPET R4 scanner. Only the brain cortices were extracted using a masking and threshold method to facilitate spatial normalization. After spatial normalization and smoothing, 3D voxel-wise and ROI based t-test were performed to identify the regions with significant different FDG uptake between the normal and deaf cats. In ROI analysis, 26 ROIs were drawn on both hemispheres, and regional mean pixel value in each ROI was normalized to the global mean of the brain. Cat brains were spatially normalized well onto the target brain due to the removal of background activity. When cerebral glucose metabolism of deaf cats were compared to the normal controls after removing the effects of the global count, the glucose metabolism in the auditory cortex, head of caudate nucleus, and thalamus in both hemispheres of the deaf cats was significantly lower than that of the controls (P<0.01). No area showed a significantly increased metabolism in the deaf cats even in higher significance level (P<0.05). ROI analysis also showed significant reduction of glucose metabolism in the same region. This study established and confirmed a method for voxel-based analysis of animal PET data of cat brain, which showed high localization accuracy and specificity and was useful for examining the cerebral glucose metabolism in a cat cortical deafness model

  9. [Study of Image Quality Comparison Based on the MTF Method Between Different Medical Rigid Endoscopes in an In Vitro Model].

    Science.gov (United States)

    Wang, Yunlong; Ji, Jun; Jiang, Changsong; Huang, Zengyue

    2015-04-01

    This study was aimed to use the method of modulation transfer function (MTF) to compare image quality among three different Olympus medical rigid cystoscopes in an in vitro model. During the experimental processes, we firstly used three different types of cystoscopes (i. e. OLYMPUS cystourethroscopy with FOV of 12 degrees, OLYMPUS Germany A22003A and OLYMPUS A2013A) to collect raster images at different brightness with industrial camera and computer from the resolution target which is with different spatial frequency, and then we processed the collected images using MALAB software with the optical transfer function MTF to obtain the values of MTF at different brightness and different spatial frequency. We then did data mathematical statistics and compared imaging quality. The statistical data showed that all three MTF values were smaller than 1. MTF values with the spatial frequency gradually increasing would decrease approaching 0 at the same brightness. When the brightness enhanced in the same process at the same spatial frequency, MTF values showed a slowly increasing trend. The three endoscopes' MTF values were completely different. In some cases the MTF values had a large difference, and the maximum difference could reach 0.7. Conclusion can be derived from analysis of experimental data that three Olympus medical rigid cystoscopes have completely different imaging quality abilities. The No. 3 endoscope OLYMPUS A2013A has low resolution but high contrast. The No. 1 endoscope OLYMPUS cystourethroscopy with FOV of 12 degrees, on the contrary, had high resolution and lower contrast. The No. 2 endoscope OLYMPUS Germany A22003A had high contrast and high resolution, and its image quality was the best.

  10. Comparison of validation methods for forming simulations

    Science.gov (United States)

    Schug, Alexander; Kapphan, Gabriel; Bardl, Georg; Hinterhölzl, Roland; Drechsler, Klaus

    2018-05-01

    The forming simulation of fibre reinforced thermoplastics could reduce the development time and improve the forming results. But to take advantage of the full potential of the simulations it has to be ensured that the predictions for material behaviour are correct. For that reason, a thorough validation of the material model has to be conducted after characterising the material. Relevant aspects for the validation of the simulation are for example the outer contour, the occurrence of defects and the fibre paths. To measure these features various methods are available. Most relevant and also most difficult to measure are the emerging fibre orientations. For that reason, the focus of this study was on measuring this feature. The aim was to give an overview of the properties of different measuring systems and select the most promising systems for a comparison survey. Selected were an optical, an eddy current and a computer-assisted tomography system with the focus on measuring the fibre orientations. Different formed 3D parts made of unidirectional glass fibre and carbon fibre reinforced thermoplastics were measured. Advantages and disadvantages of the tested systems were revealed. Optical measurement systems are easy to use, but are limited to the surface plies. With an eddy current system also lower plies can be measured, but it is only suitable for carbon fibres. Using a computer-assisted tomography system all plies can be measured, but the system is limited to small parts and challenging to evaluate.

  11. Comparison of automatic and visual methods used for image segmentation in Endodontics: a microCT study.

    Science.gov (United States)

    Queiroz, Polyane Mazucatto; Rovaris, Karla; Santaella, Gustavo Machado; Haiter-Neto, Francisco; Freitas, Deborah Queiroz

    2017-01-01

    To calculate root canal volume and surface area in microCT images, an image segmentation by selecting threshold values is required, which can be determined by visual or automatic methods. Visual determination is influenced by the operator's visual acuity, while the automatic method is done entirely by computer algorithms. To compare between visual and automatic segmentation, and to determine the influence of the operator's visual acuity on the reproducibility of root canal volume and area measurements. Images from 31 extracted human anterior teeth were scanned with a μCT scanner. Three experienced examiners performed visual image segmentation, and threshold values were recorded. Automatic segmentation was done using the "Automatic Threshold Tool" available in the dedicated software provided by the scanner's manufacturer. Volume and area measurements were performed using the threshold values determined both visually and automatically. The paired Student's t-test showed no significant difference between visual and automatic segmentation methods regarding root canal volume measurements (p=0.93) and root canal surface (p=0.79). Although visual and automatic segmentation methods can be used to determine the threshold and calculate root canal volume and surface, the automatic method may be the most suitable for ensuring the reproducibility of threshold determination.

  12. [Comparison study on sampling methods of Oncomelania hupensis snail survey in marshland schistosomiasis epidemic areas in China].

    Science.gov (United States)

    An, Zhao; Wen-Xin, Zhang; Zhong, Yao; Yu-Kuan, Ma; Qing, Liu; Hou-Lang, Duan; Yi-di, Shang

    2016-06-29

    To optimize and simplify the survey method of Oncomelania hupensis snail in marshland endemic region of schistosomiasis and increase the precision, efficiency and economy of the snail survey. A quadrate experimental field was selected as the subject of 50 m×50 m size in Chayegang marshland near Henghu farm in the Poyang Lake region and a whole-covered method was adopted to survey the snails. The simple random sampling, systematic sampling and stratified random sampling methods were applied to calculate the minimum sample size, relative sampling error and absolute sampling error. The minimum sample sizes of the simple random sampling, systematic sampling and stratified random sampling methods were 300, 300 and 225, respectively. The relative sampling errors of three methods were all less than 15%. The absolute sampling errors were 0.221 7, 0.302 4 and 0.047 8, respectively. The spatial stratified sampling with altitude as the stratum variable is an efficient approach of lower cost and higher precision for the snail survey.

  13. Comparison of three different methods for assessing in situ friction velocity: A case study from Loch Etive, Scotland

    DEFF Research Database (Denmark)

    Inoue, Tetsunori; Glud, Ronnie N.; Stahl, Henrik

    2011-01-01

    Three approaches, Eddy Correlation (EC), Turbulent Kinetic Energy (TKE), and Inertial Dissipation (ID) methods, were compared to evaluate their potential for estimation of friction velocity in a Scottish sea loch. As an independent assessment parameter, we used simultaneous O2 recordings of the d...

  14. Cryopreservation of human oocytes, zygotes, embryos and blastocysts: A comparison study between slow freezing and ultra rapid (vitrification methods

    Directory of Open Access Journals (Sweden)

    Tahani Al-Azawi

    2013-12-01

    Full Text Available Preservation of female genetics is currently done primarily by means of oocyte and embryo cryopreservation. The field has seen much progress during its four-decade history, progress driven predominantly by research in humans. It can also be done by preservation of ovarian tissue or entire ovary for transplantation, followed by oocyte harvesting or natural fertilization. Two basic cryopreservation techniques rule the field, slow-rate freezing, the first to be developed and vitrification which in recent years, has gained a foothold. The slow-rate freezing method previously reported had low survival and pregnancy rates, along with the high cost of cryopreservation. Although there are some recent data indicating better survival rates, cryopreservation by the slow freezing method has started to discontinue. Vitrification of human embryos, especially at early stages, became a more popular alternative to the slow rate freezing method due to reported comparable clinical and laboratory outcomes. In addition, vitrification is relatively simple, requires no expensive programmable freezing equipment, and uses a small amount of liquid nitrogen for freezing. Moreover, oocyte cryopreservation using vitrification has been proposed as a solution to maintain women’s fertility by serving and freezing their oocytes at the optimal time. The aim of this research is to compare slow freezing and vitrification in cryopreservation of oocytes, zygotes, embryos and blastocysts during the last twelve years. Therefore, due to a lot of controversies in this regard, we tried to achieve an exact idea about the subject and the best technique used.

  15. Comparison of infusion pumps calibration methods

    Science.gov (United States)

    Batista, Elsa; Godinho, Isabel; do Céu Ferreira, Maria; Furtado, Andreia; Lucas, Peter; Silva, Claudia

    2017-12-01

    Nowadays, several types of infusion pump are commonly used for drug delivery, such as syringe pumps and peristaltic pumps. These instruments present different measuring features and capacities according to their use and therapeutic application. In order to ensure the metrological traceability of these flow and volume measuring equipment, it is necessary to use suitable calibration methods and standards. Two different calibration methods can be used to determine the flow error of infusion pumps. One is the gravimetric method, considered as a primary method, commonly used by National Metrology Institutes. The other calibration method, a secondary method, relies on an infusion device analyser (IDA) and is typically used by hospital maintenance offices. The suitability of the IDA calibration method was assessed by testing several infusion instruments at different flow rates using the gravimetric method. In addition, a measurement comparison between Portuguese Accredited Laboratories and hospital maintenance offices was performed under the coordination of the Portuguese Institute for Quality, the National Metrology Institute. The obtained results were directly related to the used calibration method and are presented in this paper. This work has been developed in the framework of the EURAMET projects EMRP MeDD and EMPIR 15SIP03.

  16. Evaluation of rainfall structure on hydrograph simulation: Comparison of radar and interpolated methods, a study case in a tropical catchment

    Science.gov (United States)

    Velasquez, N.; Ochoa, A.; Castillo, S.; Hoyos Ortiz, C. D.

    2017-12-01

    The skill of river discharge simulation using hydrological models strongly depends on the quality and spatio-temporal representativeness of precipitation during storm events. All precipitation measurement strategies have their own strengths and weaknesses that translate into discharge simulation uncertainties. Distributed hydrological models are based on evolving rainfall fields in the same time scale as the hydrological simulation. In general, rainfall measurements from a dense and well maintained rain gauge network provide a very good estimation of the total volume for each rainfall event, however, the spatial structure relies on interpolation strategies introducing considerable uncertainty in the simulation process. On the other hand, rainfall retrievals from radar reflectivity achieve a better spatial structure representation but with higher uncertainty in the surface precipitation intensity and volume depending on the vertical rainfall characteristics and radar scan strategy. To assess the impact of both rainfall measurement methodologies on hydrological simulations, and in particular the effects of the rainfall spatio-temporal variability, a numerical modeling experiment is proposed including the use of a novel QPE (Quantitative Precipitation Estimation) method based on disdrometer data in order to estimate surface rainfall from radar reflectivity. The experiment is based on the simulation of 84 storms, the hydrological simulations are carried out using radar QPE and two different interpolation methods (IDW and TIN), and the assessment of simulated peak flow. Results show significant rainfall differences between radar QPE and the interpolated fields, evidencing a poor representation of storms in the interpolated fields, which tend to miss the precise location of the intense precipitation cores, and to artificially generate rainfall in some areas of the catchment. Regarding streamflow modelling, the potential improvement achieved by using radar QPE depends on

  17. A Simulation-Based Study on the Comparison of Statistical and Time Series Forecasting Methods for Early Detection of Infectious Disease Outbreaks.

    Science.gov (United States)

    Yang, Eunjoo; Park, Hyun Woo; Choi, Yeon Hwa; Kim, Jusim; Munkhdalai, Lkhagvadorj; Musa, Ibrahim; Ryu, Keun Ho

    2018-05-11

    Early detection of infectious disease outbreaks is one of the important and significant issues in syndromic surveillance systems. It helps to provide a rapid epidemiological response and reduce morbidity and mortality. In order to upgrade the current system at the Korea Centers for Disease Control and Prevention (KCDC), a comparative study of state-of-the-art techniques is required. We compared four different temporal outbreak detection algorithms: the CUmulative SUM (CUSUM), the Early Aberration Reporting System (EARS), the autoregressive integrated moving average (ARIMA), and the Holt-Winters algorithm. The comparison was performed based on not only 42 different time series generated taking into account trends, seasonality, and randomly occurring outbreaks, but also real-world daily and weekly data related to diarrhea infection. The algorithms were evaluated using different metrics. These were namely, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), F1 score, symmetric mean absolute percent error (sMAPE), root-mean-square error (RMSE), and mean absolute deviation (MAD). Although the comparison results showed better performance for the EARS C3 method with respect to the other algorithms, despite the characteristics of the underlying time series data, Holt⁻Winters showed better performance when the baseline frequency and the dispersion parameter values were both less than 1.5 and 2, respectively.

  18. Comparison of conventional versus Hybrid knife peroral endoscopic myotomy methods for esophageal achalasia: a case-control study.

    Science.gov (United States)

    Tang, Xiaowei; Gong, Wei; Deng, Zhiliang; Zhou, Jieqiong; Ren, Yutang; Zhang, Qiang; Chen, Zhenyu; Jiang, Bo

    2016-01-01

    Peroral endoscopic myotomy (POEM) has been developed to treat achalasia as a novel less invasive modality. We aimed to compare the efficacy and safety of conventional knife versus Hybrid knife (HK) during POEM procedure. Between June 2012 and July 2014, 31 patients underwent POEM using HK in our department (HK group), and 36 patients underwent POEM using conventional method (injection needle and triangular tip [TT] knife, TT group). Procedure-related parameters, symptom relief, adverse events were compared between two groups. There were no significant differences in the age, sex and other baseline characteristics between the two groups. The mean procedural time was significantly shorter in HK group than TT group (53.0 ± 17.2 vs. 67.6 ± 28.4 min, p = 0.015). The mean frequency of devices exchange was 4.7 ± 1.7 in HK group and 10.9 ± 1.8 in TT group (p = 0.000). No serious adverse events occurred postoperatively in both groups. At one-year follow-up, a total of 94% treatment success was achieved in all patients (93.5% in HK group and 94.4% in TT group, p = 0.877). HK in POEM can shorten the procedural time, and achieve similar treatment success compared to conventional TT knife.

  19. Input-Output Analysis for Sustainability by Using DEA Method: A Comparison Study between European and Asian Countries

    Directory of Open Access Journals (Sweden)

    Wen-Hsien Tsai

    2016-11-01

    Full Text Available Policymakers around the world are confronted with the challenge of balancing between economic development and environmental friendliness, which entails a robust set of measures in energy efficiency and environmental protection. The increasing complexity of these issues has imposed pressure on the Asian countries that have been acting as global factories. This paper proposes a meta-frontier slacks-based measure (SBM data envelopment analysis (DEA model, with the hope that policymakers clarify the relationship between labor force, energy consumption, government expenditures, GDP, and CO2 emissions. Clarification of the causal relationship can serve as a template for policy decisions and ease concerns regarding the potential adverse effects of carbon reduction and energy efficiency on the economy. The results show: (1 Developing countries should establish their own climate change governance and policy frameworks; (2 Developed economies should seek to lower carbon emissions; (3 Energy policies play a pivotal role in energy efficiency improvement; (4 Top-down efforts are critical for the success of carbon reduction policies; (5 Learning from the success of developed countries helps to improve the effectiveness of energy policies; (6 Environmental policies should be formulated, and new production technologies, pollution prevention measures, and treatment methods should be introduced; (7 Governments are suggested to build long-term independent management institutions to promote energy cooperation and exchange.

  20. COMPARISON OF METHODS FOR GEOMETRIC CAMERA CALIBRATION

    Directory of Open Access Journals (Sweden)

    J. Hieronymus

    2012-09-01

    Full Text Available Methods for geometric calibration of cameras in close-range photogrammetry are established and well investigated. The most common one is based on test-fields with well-known pattern, which are observed from different directions. The parameters of a distortion model are calculated using bundle-block-adjustment-algorithms. This methods works well for short focal lengths, but is essentially more problematic to use with large focal lengths. Those would require very large test-fields and surrounding space. To overcome this problem, there is another common method for calibration used in remote sensing. It employs measurements using collimator and a goniometer. A third calibration method uses diffractive optical elements (DOE to project holograms of well known pattern. In this paper these three calibration methods are compared empirically, especially in terms of accuracy. A camera has been calibrated with those methods mentioned above. All methods provide a set of distortion correction parameters as used by the photogrammetric software Australis. The resulting parameter values are very similar for all investigated methods. The three sets of distortion parameters are crosscompared against all three calibration methods. This is achieved by inserting the gained distortion parameters as fixed input into the calibration algorithms and only adjusting the exterior orientation. The RMS (root mean square of the remaining image coordinate residuals are taken as a measure of distortion correction quality. There are differences resulting from the different calibration methods. Nevertheless the measure is small for every comparison, which means that all three calibration methods can be used for accurate geometric calibration.

  1. Comparison of thoracolumbar motion produced by manual and Jackson-table-turning methods. Study of a cadaveric instability model.

    Science.gov (United States)

    DiPaola, Christian P; DiPaola, Matthew J; Conrad, Bryan P; Horodyski, MaryBeth; Del Rossi, Gianluca; Sawers, Andrew; Rechtine, Glenn R

    2008-08-01

    Patients who have sustained a spinal cord injury remain at risk for further neurologic deterioration until the spine is adequately stabilized. To our knowledge, no study has previously addressed the effects of different bed-to-operating room table transfer techniques on thoracolumbar spinal motion in an instability model. We hypothesized that the conventional logroll technique used to transfer patients from a supine position to a prone position on the operating room table has the potential to confer significantly more motion to the unstable thoracolumbar spine than the Jackson technique. Three-column instability was surgically created at the L1 level in seven cadavers. Two protocols were tested. The manual technique entailed performing a standard logroll of a supine cadaver to a prone position on an operating room Jackson table. The Jackson technique involved sliding the supine cadaver to the Jackson table, securing it to the table, and then rotating it into a prone position. An electromagnetic tracking device measured motion--i.e., angular motion (flexion-extension, lateral bending, and axial rotation) and linear translation (axial, medial-lateral, and anterior-posterior) between T12 and L2. The logroll technique created significantly more motion than the Jackson technique as measured with all six parameters. Manual logroll transfers produced an average of 13.8 degrees to 18.1 degrees of maximum angular displacement and 16.6 to 28.3 mm of maximum linear translation. The Jackson technique resulted in an average of 3.1 degrees to 5.8 degrees of maximum angular displacement (p patient safety. Performing the Jackson turn requires approximately half as many people as required for a manual logroll. This study suggests that the Jackson technique should be considered for supine-to-prone transfer of patients with known or suspected instability of the thoracolumbar spine.

  2. Optimization and Comparison of ESI and APCI LC-MS/MS Methods: A Case Study of Irgarol 1051, Diuron, and their Degradation Products in Environmental Samples

    Science.gov (United States)

    Maragou, Niki C.; Thomaidis, Nikolaos S.; Koupparis, Michael A.

    2011-10-01

    A systematic and detailed optimization strategy for the development of atmospheric pressure ionization (API) LC-MS/MS methods for the determination of Irgarol 1051, Diuron, and their degradation products (M1, DCPMU, DCPU, and DCA) in water, sediment, and mussel is described. Experimental design was applied for the optimization of the ion sources parameters. Comparison of ESI and APCI was performed in positive- and negative-ion mode, and the effect of the mobile phase on ionization was studied for both techniques. Special attention was drawn to the ionization of DCA, which presents particular difficulty in API techniques. Satisfactory ionization of this small molecule is achieved only with ESI positive-ion mode using acetonitrile in the mobile phase; the instrumental detection limit is 0.11 ng/mL. Signal suppression was qualitatively estimated by using purified and non-purified samples. The sample preparation for sediments and mussels is direct and simple, comprising only solvent extraction. Mean recoveries ranged from 71% to 110%, and the corresponding (%) RSDs ranged between 4.1 and 14%. The method limits of detection ranged between 0.6 and 3.5 ng/g for sediment and mussel and from 1.3 to 1.8 ng/L for sea water. The method was applied to sea water, marine sediment, and mussels, which were obtained from marinas in Attiki, Greece. Ion ratio confirmation was used for the identification of the compounds.

  3. Characterization and stability studies of a novel liposomal cyclosporin A prepared using the supercritical fluid method: comparison with the modified conventional Bangham method

    Directory of Open Access Journals (Sweden)

    Karn PR

    2013-01-01

    Full Text Available Pankaj Ranjan Karn,1,3 Wonkyung Cho,1,3 Hee-Jun Park,1,3 Jeong-Sook Park,3 Sung-Joo Hwang1,21Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Yeonsu-gu, Incheon, Republic of Korea; 2College of Pharmacy, Yonsei University, Yeonsu-gu, Incheon, Republic of Korea; 3College of Pharmacy, Chungnam National University, Yuseong-gu, Daejeon, Republic of KoreaAbstract: A novel method to prepare cyclosporin A encapsulated liposomes was introduced using supercritical fluid of carbon dioxide (SCF-CO2 as an antisolvent. To investigate the strength of the newly developed SCF-CO2 method compared with the modified conventional Bangham method, particle size, zeta potential, and polydispersity index (PDI of both liposomal formulations were characterized and compared. In addition, entrapment efficiency (EE and drug loading (DL characteristics were analyzed by reversed-phase high-performance liquid chromatography. Significantly larger particle size and PDI were revealed from the conventional method, while EE (% and DL (% did not exhibit any significant differences. The SCF-CO2 liposomes were found to be relatively smaller, multilamellar, and spherical with a smoother surface as determined by transmission electron microscopy. SCF-CO2 liposomes showed no significant differences in their particle size and PDI after more than 3 months, whereas conventional liposomes exhibited significant changes in their particle size. The initial yield (%, EE (%, and DL (% of SCF-CO2 liposomes and conventional liposomes were 90.98 ± 2.94, 92.20 ± 1.36, 20.99 ± 0.84 and 90.72 ± 2.83, 90.24 ± 1.37, 20.47 ± 0.94, respectively, which changed after 14 weeks to 86.65 ± 0.30, 87.63 ± 0.72, 18.98 ± 0.22 and 75.04 ± 8.80, 84.59 ± 5.13, 15.94 ± 2.80, respectively. Therefore, the newly developed SCF-CO2 method could be a better alternative compared with the conventional method and may provide a promising approach for large-scale production of liposomes

  4. A study of biodiversity using DSS method and seed storage protein comparison of populations in two species of Achillea L. in the west of Iran

    Directory of Open Access Journals (Sweden)

    Hajar Salehi

    2013-11-01

    Full Text Available Intarspecific and interspecific variations are the main reserves of biodiversity and both are important sources of speciation. On this basis, identifing and recognizing the intra and interspecific variations is important in order to recognition of biodiversity. This research was done to study biodiversity and electrophoresis comparison of seed storage proteins in the populations of the two species of the genus Achillea in Hamadan and Kurdistan provinces using of the method of determination of special station (DSS. For this purpose, 12 and 9 special stations were selected for the species A. tenuifolia and A. biebresteinii using the data published in the related flora. Seed storage proteins were extracted and then studied using electrophoresis techniques (SDS-PAGE. In survey of all special stations, 120 plant species were distinguished as associated species. The results of the floristic data for the both species determined six distinctive groups that indicated the existence of intraspecific diversity in this species. The result of analysis of ecological data and seed storage proteins for the two species was in accordance with the floristic data and showed six distinctive groups. The existence of the bands of no. 4, 5, 8, 12 and 13 in the special stations of A. tenuifolia and the bands of 14, 15 and 16 in the special stations of A. biebresteinii o separated the populations of the species in two quite different and distinctive groups.

  5. Standard setting: Comparison of two methods

    Directory of Open Access Journals (Sweden)

    Oyebode Femi

    2006-09-01

    Full Text Available Abstract Background The outcome of assessments is determined by the standard-setting method used. There is a wide range of standard – setting methods and the two used most extensively in undergraduate medical education in the UK are the norm-reference and the criterion-reference methods. The aims of the study were to compare these two standard-setting methods for a multiple-choice question examination and to estimate the test-retest and inter-rater reliability of the modified Angoff method. Methods The norm – reference method of standard -setting (mean minus 1 SD was applied to the 'raw' scores of 78 4th-year medical students on a multiple-choice examination (MCQ. Two panels of raters also set the standard using the modified Angoff method for the same multiple-choice question paper on two occasions (6 months apart. We compared the pass/fail rates derived from the norm reference and the Angoff methods and also assessed the test-retest and inter-rater reliability of the modified Angoff method. Results The pass rate with the norm-reference method was 85% (66/78 and that by the Angoff method was 100% (78 out of 78. The percentage agreement between Angoff method and norm-reference was 78% (95% CI 69% – 87%. The modified Angoff method had an inter-rater reliability of 0.81 – 0.82 and a test-retest reliability of 0.59–0.74. Conclusion There were significant differences in the outcomes of these two standard-setting methods, as shown by the difference in the proportion of candidates that passed and failed the assessment. The modified Angoff method was found to have good inter-rater reliability and moderate test-retest reliability.

  6. Standard setting: comparison of two methods.

    Science.gov (United States)

    George, Sanju; Haque, M Sayeed; Oyebode, Femi

    2006-09-14

    The outcome of assessments is determined by the standard-setting method used. There is a wide range of standard-setting methods and the two used most extensively in undergraduate medical education in the UK are the norm-reference and the criterion-reference methods. The aims of the study were to compare these two standard-setting methods for a multiple-choice question examination and to estimate the test-retest and inter-rater reliability of the modified Angoff method. The norm-reference method of standard-setting (mean minus 1 SD) was applied to the 'raw' scores of 78 4th-year medical students on a multiple-choice examination (MCQ). Two panels of raters also set the standard using the modified Angoff method for the same multiple-choice question paper on two occasions (6 months apart). We compared the pass/fail rates derived from the norm reference and the Angoff methods and also assessed the test-retest and inter-rater reliability of the modified Angoff method. The pass rate with the norm-reference method was 85% (66/78) and that by the Angoff method was 100% (78 out of 78). The percentage agreement between Angoff method and norm-reference was 78% (95% CI 69% - 87%). The modified Angoff method had an inter-rater reliability of 0.81-0.82 and a test-retest reliability of 0.59-0.74. There were significant differences in the outcomes of these two standard-setting methods, as shown by the difference in the proportion of candidates that passed and failed the assessment. The modified Angoff method was found to have good inter-rater reliability and moderate test-retest reliability.

  7. Comparison of two fractal interpolation methods

    Science.gov (United States)

    Fu, Yang; Zheng, Zeyu; Xiao, Rui; Shi, Haibo

    2017-03-01

    As a tool for studying complex shapes and structures in nature, fractal theory plays a critical role in revealing the organizational structure of the complex phenomenon. Numerous fractal interpolation methods have been proposed over the past few decades, but they differ substantially in the form features and statistical properties. In this study, we simulated one- and two-dimensional fractal surfaces by using the midpoint displacement method and the Weierstrass-Mandelbrot fractal function method, and observed great differences between the two methods in the statistical characteristics and autocorrelation features. From the aspect of form features, the simulations of the midpoint displacement method showed a relatively flat surface which appears to have peaks with different height as the fractal dimension increases. While the simulations of the Weierstrass-Mandelbrot fractal function method showed a rough surface which appears to have dense and highly similar peaks as the fractal dimension increases. From the aspect of statistical properties, the peak heights from the Weierstrass-Mandelbrot simulations are greater than those of the middle point displacement method with the same fractal dimension, and the variances are approximately two times larger. When the fractal dimension equals to 1.2, 1.4, 1.6, and 1.8, the skewness is positive with the midpoint displacement method and the peaks are all convex, but for the Weierstrass-Mandelbrot fractal function method the skewness is both positive and negative with values fluctuating in the vicinity of zero. The kurtosis is less than one with the midpoint displacement method, and generally less than that of the Weierstrass-Mandelbrot fractal function method. The autocorrelation analysis indicated that the simulation of the midpoint displacement method is not periodic with prominent randomness, which is suitable for simulating aperiodic surface. While the simulation of the Weierstrass-Mandelbrot fractal function method has

  8. Comparison of Witczak NCHRP 1-40D & Hirsh dynamic modulus models based on different binder characterization methods: a case study

    Directory of Open Access Journals (Sweden)

    Khattab Ahmed M.

    2017-01-01

    Full Text Available The Pavement ME Design method considers the hot mix asphalt (HMA dynamic modulus (E* as the main mechanistic property that affects pavement performance. For the HMA, E* can be determined directly by laboratory testing (level 1 or it can be estimated using predictive equations (levels 2 and 3. Pavement-ME Design introduced the NCHRP1-40D model as the latest model for predicting E* when levels 2 or 3 HMA inputs are used. This study focused on utilizing laboratory measured E* data to compare NCHRP1-40D model with Hirsh model. This comparison included the evaluation of the binder characterization level as per Pavement ME Design and its influence on the performance of these models. E*tests were conducted in the laboratory on 25 local mixes representing different road construction projects in the kingdom of Saudi Arabia. The main tests for the mix binders were dynamic Shear Rheometer (DSR and Brookfield Rotational Viscometer (RV. Results showed that both models with level 3 binder data produced very similar accuracy. The highest accuracy and lowest bias for both models occurred with level 3 binder data. Finally, the accuracy of prediction and level of bias for both models were found to be a function of the binder input level.

  9. Arima model and exponential smoothing method: A comparison

    Science.gov (United States)

    Wan Ahmad, Wan Kamarul Ariffin; Ahmad, Sabri

    2013-04-01

    This study shows the comparison between Autoregressive Moving Average (ARIMA) model and Exponential Smoothing Method in making a prediction. The comparison is focused on the ability of both methods in making the forecasts with the different number of data sources and the different length of forecasting period. For this purpose, the data from The Price of Crude Palm Oil (RM/tonne), Exchange Rates of Ringgit Malaysia (RM) in comparison to Great Britain Pound (GBP) and also The Price of SMR 20 Rubber Type (cents/kg) with three different time series are used in the comparison process. Then, forecasting accuracy of each model is measured by examinethe prediction error that producedby using Mean Squared Error (MSE), Mean Absolute Percentage Error (MAPE), and Mean Absolute deviation (MAD). The study shows that the ARIMA model can produce a better prediction for the long-term forecasting with limited data sources, butcannot produce a better prediction for time series with a narrow range of one point to another as in the time series for Exchange Rates. On the contrary, Exponential Smoothing Method can produce a better forecasting for Exchange Rates that has a narrow range of one point to another for its time series, while itcannot produce a better prediction for a longer forecasting period.

  10. Method and apparatus for biological sequence comparison

    Science.gov (United States)

    Marr, T.G.; Chang, W.I.

    1997-12-23

    A method and apparatus are disclosed for comparing biological sequences from a known source of sequences, with a subject (query) sequence. The apparatus takes as input a set of target similarity levels (such as evolutionary distances in units of PAM), and finds all fragments of known sequences that are similar to the subject sequence at each target similarity level, and are long enough to be statistically significant. The invention device filters out fragments from the known sequences that are too short, or have a lower average similarity to the subject sequence than is required by each target similarity level. The subject sequence is then compared only to the remaining known sequences to find the best matches. The filtering member divides the subject sequence into overlapping blocks, each block being sufficiently large to contain a minimum-length alignment from a known sequence. For each block, the filter member compares the block with every possible short fragment in the known sequences and determines a best match for each comparison. The determined set of short fragment best matches for the block provide an upper threshold on alignment values. Regions of a certain length from the known sequences that have a mean alignment value upper threshold greater than a target unit score are concatenated to form a union. The current block is compared to the union and provides an indication of best local alignment with the subject sequence. 5 figs.

  11. An interlaboratory comparison of methods for measuring rock matrix porosity

    International Nuclear Information System (INIS)

    Rasilainen, K.; Hellmuth, K.H.; Kivekaes, L.; Ruskeeniemi, T.; Melamed, A.; Siitari-Kauppi, M.

    1996-09-01

    An interlaboratory comparison study was conducted for the available Finnish methods of rock matrix porosity measurements. The aim was first to compare different experimental methods for future applications, and second to obtain quality assured data for the needs of matrix diffusion modelling. Three different versions of water immersion techniques, a tracer elution method, a helium gas through-diffusion method, and a C-14-PMMA method were tested. All methods selected for this study were established experimental tools in the respective laboratories, and they had already been individually tested. Rock samples for the study were obtained from a homogeneous granitic drill core section from the natural analogue site at Palmottu. The drill core section was cut into slabs that were expected to be practically identical. The subsamples were then circulated between the different laboratories using a round robin approach. The circulation was possible because all methods were non-destructive, except the C-14-PMMA method, which was always the last method to be applied. The possible effect of drying temperature on the measured porosity was also preliminarily tested. These measurements were done in the order of increasing drying temperature. Based on the study, it can be concluded that all methods are comparable in their accuracy. The selection of methods for future applications can therefore be based on practical considerations. Drying temperature seemed to have very little effect on the measured porosity, but a more detailed study is needed for definite conclusions. (author) (4 refs.)

  12. Improved methods for the mathematically controlled comparison of biochemical systems

    Directory of Open Access Journals (Sweden)

    Schwacke John H

    2004-06-01

    Full Text Available Abstract The method of mathematically controlled comparison provides a structured approach for the comparison of alternative biochemical pathways with respect to selected functional effectiveness measures. Under this approach, alternative implementations of a biochemical pathway are modeled mathematically, forced to be equivalent through the application of selected constraints, and compared with respect to selected functional effectiveness measures. While the method has been applied successfully in a variety of studies, we offer recommendations for improvements to the method that (1 relax requirements for definition of constraints sufficient to remove all degrees of freedom in forming the equivalent alternative, (2 facilitate generalization of the results thus avoiding the need to condition those findings on the selected constraints, and (3 provide additional insights into the effect of selected constraints on the functional effectiveness measures. We present improvements to the method and related statistical models, apply the method to a previously conducted comparison of network regulation in the immune system, and compare our results to those previously reported.

  13. Comparison of green method for chitin deacetylation

    Science.gov (United States)

    Anwar, Muslih; Anggraeni, Ayu Septi; Amin, M. Harisuddin Al

    2017-03-01

    Developing highly environmentally friendly and cost-effective approaches for the chitosan production has paramount important in the future technology. Deacetylation process is one of the most importing steps to classify the quality of chitosan. This research aimed to study the best method for deacetylation of chitin considered by several factors like the concentration of base, temperature, time and reaction method. From the green chemistry point of view, conventional refluxing method relatively wasted energy compared to another method such as maceration, grinding and sonication. The degree of deacetylation (DD) of chitosan was studied by sonication, resulted in slightly increasing of DD from 73.14 to 73.28% during the time from 0.5 h to 1 h. Deacetylation of chitin with various sodium hydroxide concentration 60, 70 and 80% gave 73.14, 76.36 and 77.88% of DD, respectively. Variation of temperature at 40, 60, and 80 °C was slightly affected on increasing DD from 67.53, 72.84 and 73.14%, respectively. The DD of chitosan significantly increased from 60.19, 74.27 and 81.20% respectively correspondent to varying NaOH concentration 60, 70 and 80% using the maceration method. Solid phase grinding method for half hour resulted in 79.49% of DD. The application of ultrasound grinding method not only was enhanced toward the deacetylation but also favoured the depolymerization process. Moreover, maceration for 7 days with 80% NaOH can be as an alternative method.

  14. A Comparison Study between Two MPPT Control Methods for a Large Variable-Speed Wind Turbine under Different Wind Speed Characteristics

    Directory of Open Access Journals (Sweden)

    Dongran Song

    2017-05-01

    Full Text Available Variable speed wind turbines (VSWTs usually adopt a maximum power point tracking (MPPT method to optimize energy capture performance. Nevertheless, obtained performance offered by different MPPT methods may be affected by the impact of wind turbine (WT’s inertia and wind speed characteristics and it needs to be clarified. In this paper, the tip speed ratio (TSR and optimal torque (OT methods are investigated in terms of their performance under different wind speed characteristics on a 1.5 MW wind turbine model. To this end, the TSR control method based on an effective wind speed estimator and the OT control method are firstly presented. Then, their performance is investigated and compared through simulation test results under different wind speeds using Bladed software. Comparison results show that the TSR control method can capture slightly more wind energy at the cost of high component loads than the other one under all wind conditions. Furthermore, it is found that both control methods present similar trends of power reduction that is relevant to mean wind speed and turbulence intensity. From the obtained results, we demonstrate that, to further improve MPPT capability of large VSWTs, other advanced control methods using wind speed prediction information need to be addressed.

  15. Study on convective mixing for thermal striping phenomena. Thermal-hydraulic analyses on mixing process in parallel triple-jet and comparisons between numerical methods

    International Nuclear Information System (INIS)

    Kimura, Nobuyuki; Nishimura, Motohiko; Kamide, Hideki

    2000-03-01

    A quantitative evaluation on thermal striping, in which temperature fluctuation due to convective mixing among jets imposes thermal fatigue on structural components, is of importance for reactor safety. In the present study, a water experiment was performed on parallel triple-jet: cold jet at the center and hot jets in both sides. Three kinds of numerical analyses based on the finite difference method were carried out to compare the similarity with the experiment by use of respective different handling of turbulence such as a k-ε two equation turbulence model (k-ε Model), a low Reynolds number stress and heat flux equation model (LRSFM) and a direct numerical simulation (DNS). In the experiment, the jets were mainly mixed due to the coherent oscillation. The numerical result using k-ε Model could not reproduce the coherent oscillating motion of jets due to rolling-up fluid. The oscillations of the jets predicted by LRSFM and DNS were in good agreements with the experiment. The comparison between the coherent and random components in experimental temperature fluctuation obtained by using the phase-averaging shows that k-ε Model and LRSFM overestimated the random component and the coherent component respectively. The ratios of coherent to random components in total temperature fluctuation obtained from DNS were in good agreements with the experiment. The numerical analysis using DNS can reproduce the coherent oscillation of the jets and the coherent / random components in temperature fluctuation. The analysis using LRSFM could simulate the mixing process of the jets with the low frequency. (author)

  16. Comparison of Thermal Properties Measured by Different Methods

    Energy Technology Data Exchange (ETDEWEB)

    Sundberg, Jan [Geo Innova AB, Linkoeping (Sweden); Kukkonen, Ilmo [Geological Survey of Finland, Helsinki (Finland); Haelldahl, Lars [Hot Disk AB, Uppsala (Sweden)

    2003-04-01

    one or both methods cannot be excluded. For future investigations a set of thermal conductivity standard materials should be selected for testing using the different methods of the laboratories. The material should have thermal properties in the range of typical rocks, be fine-grained and suitable for making samples of different shapes and volumes adjusted to different measurement techniques. Because of large obtained individual variations in the results, comparisons of different methods should continue and include measurements of temperature dependence of thermal properties, especially the specific heat. This should cover the relevant temperature range of about 0-90 deg C. Further comparisons would add to previous studies of temperature dependence of the present rocks.

  17. Comparison of Thermal Properties Measured by Different Methods

    International Nuclear Information System (INIS)

    Sundberg, Jan; Kukkonen, Ilmo; Haelldahl, Lars

    2003-04-01

    one or both methods cannot be excluded. For future investigations a set of thermal conductivity standard materials should be selected for testing using the different methods of the laboratories. The material should have thermal properties in the range of typical rocks, be fine-grained and suitable for making samples of different shapes and volumes adjusted to different measurement techniques. Because of large obtained individual variations in the results, comparisons of different methods should continue and include measurements of temperature dependence of thermal properties, especially the specific heat. This should cover the relevant temperature range of about 0-90 deg C. Further comparisons would add to previous studies of temperature dependence of the present rocks

  18. A Comparison of Distillery Stillage Disposal Methods

    Directory of Open Access Journals (Sweden)

    V. Sajbrt

    2010-01-01

    Full Text Available This paper compares the main stillage disposal methods from the point of view of technology, economics and energetics. Attention is paid to the disposal of both solid and liquid phase. Specifically, the following methods are considered: a livestock feeding, b combustion of granulated stillages, c fertilizer production, d anaerobic digestion with biogas production and e chemical pretreatment and subsequent secondary treatment. Other disposal techniques mentioned in the literature (electrofenton reaction, electrocoagulation and reverse osmosis have not been considered, due to their high costs and technological requirements.Energy and economic calculations were carried out for a planned production of 120 m3 of stillage per day in a given distillery. Only specific treatment operating costs (per 1 m3 of stillage were compared, including operational costs for energy, transport and chemicals. These values were determined for January 31st, 2009. Resulting sequence of cost effectiveness: 1. – chemical pretreatment, 2. – combustion of granulated stillage, 3. – transportation of stillage to a biogas station, 4. – fertilizer production, 5. – livestock feeding. This study found that chemical pretreatment of stillage with secondary treatment (a method developed at the Department of Process Engineering, CTU was more suitable than the other methods. Also, there are some important technical advantages. Using this method, the total operating costs are approximately 1 150 ??/day, i.e. about 9,5 ??/m3 of stillage. The price of chemicals is the most important item in these costs, representing about 85 % of the total operating costs.

  19. Analysis and comparison of biometric methods

    OpenAIRE

    Zatloukal, Filip

    2011-01-01

    The thesis deals with biometrics and biometric systems and the possibility to use these systems in the enterprise. Aim of this study is an analysis and description of selected types of biometric identification methods and their advantages and shortcomings. The work is divided into two parts. The first part is theoretical, describes the basic concepts of biometrics, biometric identification criteria, currently used identification systems, the ways of biometric systems use, performance measurem...

  20. Comparison between three different LCIA methods for aquatic ecotoxicity and a product Environmental Risk Assessment – Insights from a Detergent Case Study within OMNIITOX

    DEFF Research Database (Denmark)

    Pant, Rana; Van Hoof, Geert; Feijtel, Tom

    2004-01-01

    set of physico-chemical and toxicological effect data to enable a better comparison of the methodological differences. For the same reason, the system boundaries were kept the same in all cases, focusing on emissions into water at the disposal stage. Results and Discussion. Significant differences...... ecotoxicity is not satisfactory, unless explicit reasons for the differences are identifiable. This can hamper practical decision support, as LCA practitioners usually will not be in a position to choose the 'right' LCIA method for their specific case. This puts a challenge to the entire OMNIITOX project......) with results from an Environmental Risk Assessment (ERA). Material and Methods. The LCIA has been conducted with EDIP97 (chronic aquatic ecotoxicity) [1], USES-LCA (freshwater and marine water aquatic ecotoxicity, sometimes referred to as CML2001) [2, 3] and IMPACT 2002 (covering freshwater aquatic ecotoxicity...

  1. Assessment and comparison of methods for solar ultraviolet radiation measurements

    Energy Technology Data Exchange (ETDEWEB)

    Leszczynski, K

    1995-06-01

    In the study, the different methods to measure the solar ultraviolet radiation are compared. The methods included are spectroradiometric, erythemally weighted broadband and multi-channel measurements. The comparison of the different methods is based on a literature review and assessments of optical characteristics of the spectroradiometer Optronic 742 of the Finnish Centre for Radiation and Nuclear Safety (STUK) and of the erythemally weighted Robertson-Berger type broadband radiometers Solar Light models 500 and 501 of the Finnish Meteorological Institute and STUK. An introduction to the sources of error in solar UV measurements, to methods for radiometric characterization of UV radiometers together with methods for error reduction are presented. Reviews on experiences from world-wide UV monitoring efforts and instrumentation as well as on the results from international UV radiometer intercomparisons are also presented. (62 refs.).

  2. Assessment and comparison of methods for solar ultraviolet radiation measurements

    International Nuclear Information System (INIS)

    Leszczynski, K.

    1995-06-01

    In the study, the different methods to measure the solar ultraviolet radiation are compared. The methods included are spectroradiometric, erythemally weighted broadband and multi-channel measurements. The comparison of the different methods is based on a literature review and assessments of optical characteristics of the spectroradiometer Optronic 742 of the Finnish Centre for Radiation and Nuclear Safety (STUK) and of the erythemally weighted Robertson-Berger type broadband radiometers Solar Light models 500 and 501 of the Finnish Meteorological Institute and STUK. An introduction to the sources of error in solar UV measurements, to methods for radiometric characterization of UV radiometers together with methods for error reduction are presented. Reviews on experiences from world-wide UV monitoring efforts and instrumentation as well as on the results from international UV radiometer intercomparisons are also presented. (62 refs.)

  3. Steroid hormones in environmental matrices: extraction method comparison.

    Science.gov (United States)

    Andaluri, Gangadhar; Suri, Rominder P S; Graham, Kendon

    2017-11-09

    The U.S. Environmental Protection Agency (EPA) has developed methods for the analysis of steroid hormones in water, soil, sediment, and municipal biosolids by HRGC/HRMS (EPA Method 1698). Following the guidelines provided in US-EPA Method 1698, the extraction methods were validated with reagent water and applied to municipal wastewater, surface water, and municipal biosolids using GC/MS/MS for the analysis of nine most commonly detected steroid hormones. This is the first reported comparison of the separatory funnel extraction (SFE), continuous liquid-liquid extraction (CLLE), and Soxhlet extraction methods developed by the U.S. EPA. Furthermore, a solid phase extraction (SPE) method was also developed in-house for the extraction of steroid hormones from aquatic environmental samples. This study provides valuable information regarding the robustness of the different extraction methods. Statistical analysis of the data showed that SPE-based methods provided better recovery efficiencies and lower variability of the steroid hormones followed by SFE. The analytical methods developed in-house for extraction of biosolids showed a wide recovery range; however, the variability was low (≤ 7% RSD). Soxhlet extraction and CLLE are lengthy procedures and have been shown to provide highly variably recovery efficiencies. The results of this study are guidance for better sample preparation strategies in analytical methods for steroid hormone analysis, and SPE adds to the choice in environmental sample analysis.

  4. Comparison of urine analysis using manual and sedimentation methods.

    Science.gov (United States)

    Kurup, R; Leich, M

    2012-06-01

    Microscopic examination of urine sediment is an essential part in the evaluation of renal and urinary tract diseases. Traditionally, urine sediments are assessed by microscopic examination of centrifuged urine. However the current method used by the Georgetown Public Hospital Corporation Medical Laboratory involves uncentrifuged urine. To encourage high level of care, the results provided to the physician must be accurate and reliable for proper diagnosis. The aim of this study is to determine whether the centrifuge method is more clinically significant than the uncentrifuged method. In this study, a comparison between the results obtained from centrifuged and uncentrifuged methods were performed. A total of 167 urine samples were randomly collected and analysed during the period April-May 2010 at the Medical Laboratory, Georgetown Public Hospital Corporation. The urine samples were first analysed microscopically by the uncentrifuged, and then by the centrifuged method. The results obtained from both methods were recorded in a log book. These results were then entered into a database created in Microsoft Excel, and analysed for differences and similarities using this application. Analysis was further done in SPSS software to compare the results using Pearson ' correlation. When compared using Pearson's correlation coefficient analysis, both methods showed a good correlation between urinary sediments with the exception of white bloods cells. The centrifuged method had a slightly higher identification rate for all of the parameters. There is substantial agreement between the centrifuged and uncentrifuged methods. However the uncentrifuged method provides for a rapid turnaround time.

  5. A review and comparison of methods for recreating individual patient data from published Kaplan-Meier survival curves for economic evaluations: a simulation study.

    Science.gov (United States)

    Wan, Xiaomin; Peng, Liubao; Li, Yuanjian

    2015-01-01

    In general, the individual patient-level data (IPD) collected in clinical trials are not available to independent researchers to conduct economic evaluations; researchers only have access to published survival curves and summary statistics. Thus, methods that use published survival curves and summary statistics to reproduce statistics for economic evaluations are essential. Four methods have been identified: two traditional methods 1) least squares method, 2) graphical method; and two recently proposed methods by 3) Hoyle and Henley, 4) Guyot et al. The four methods were first individually reviewed and subsequently assessed regarding their abilities to estimate mean survival through a simulation study. A number of different scenarios were developed that comprised combinations of various sample sizes, censoring rates and parametric survival distributions. One thousand simulated survival datasets were generated for each scenario, and all methods were applied to actual IPD. The uncertainty in the estimate of mean survival time was also captured. All methods provided accurate estimates of the mean survival time when the sample size was 500 and a Weibull distribution was used. When the sample size was 100 and the Weibull distribution was used, the Guyot et al. method was almost as accurate as the Hoyle and Henley method; however, more biases were identified in the traditional methods. When a lognormal distribution was used, the Guyot et al. method generated noticeably less bias and a more accurate uncertainty compared with the Hoyle and Henley method. The traditional methods should not be preferred because of their remarkable overestimation. When the Weibull distribution was used for a fitted model, the Guyot et al. method was almost as accurate as the Hoyle and Henley method. However, if the lognormal distribution was used, the Guyot et al. method was less biased compared with the Hoyle and Henley method.

  6. Comparison study for the CCME reference method for determination of PHC in soil by using internal and external standard methods and by using silica gel column cleanup and in-situ silica gel cleanup methods

    International Nuclear Information System (INIS)

    Wang, Z.; Fingas, M.; Sigouin, L.; Yang, C.; Hollebone, B.

    2003-01-01

    The assessment, cleanup, and remediation of hydrocarbon contaminated sites is covered in the Reference Method for Canada-Wide Standard for Petroleum Hydrocarbons-Tier 1 Method. It replaces several analytical methods used in the past by some laboratories and jurisdictions in Canada. The authors conducted two comparative evaluations to validate the Tier 1 Analytical Method. The first compared the Internal and External Standard Methods, and the second compared the Silica Gel Column Cleanup Method with the In-situ Silica Gel Cleanup Method. The Canadian Council of Ministers of the Environment (CCME) Tier 1 Method recommends and requires the External Standard Method to determine petroleum hydrocarbons (PHC) in soil samples. The Internal Method is widely used to quantify various organic and inorganic pollutants in environmental samples. The Tier 1 Method offers two options for the same extract cleanup. They are: Option A - In-situ Silica Gel Cleanup, and Option B - Silica Gel Column Cleanup. Linearity, precision, and PHC quantification results were the parameters considered for diesel and motor oil solutions, for diesel spiked soil samples, and for motor oil spiked soil samples. It was concluded that both the External and Internal Standard Methods for gas chromatograph (GC) determination of PHC in soil possess their own advantages. The PHC results obtained using the In-Situ Silica Gel Cleanup Method were lower than those obtained with the Silica Gel Column Cleanup Methods. The more efficient and effective sample cleanup method proved to be the Silica Gel Column Method. 13 refs., 7 tabs., 7 figs

  7. Comparison of n-γ discrimination by zero-crossing and digital charge comparison methods

    International Nuclear Information System (INIS)

    Wolski, D.; Moszynski, M.; Ludziejewski, T.; Johnson, A.; Klamra, W.; Skeppstedt, Oe.

    1995-01-01

    A comparative study of the n-γ discrimination done by the digital charge comparison and zero-crossing methods was carried out for a 130 mm in diameter and 130 mm high BC501A liquid scintillator coupled to a 130 mm diameter XP4512B photomultiplier. The high quality of the tested detector was reflected in a photoelectron yield of 2300±100 phe/MeV and excellent n-γ discrimination properties with energy discrimination thresholds corresponding to very low neutron (or electron) energies. The superiority of the Z/C method was demonstrated for the n-γ discrimination method alone, as well as, for the simultaneous separation by the pulse shape discrimination and the time-of-flight methods down to about 30 keV recoil electron energy. The digital charge comparison method fails for a large dynamic range of energy and its separation is weakly improved by time-of-flight method for low energies. (orig.)

  8. Comparison of methods for intestinal histamine application

    DEFF Research Database (Denmark)

    Vind, S; Søondergaard, I; Poulsen, L K

    1991-01-01

    The study was conducted to investigate whether introduction of histamine in enterosoluble capsules produced the same amount of urinary histamine metabolites as that found after application of histamine through a duodeno-jejunal tube. Secondly, to examine whether a histamine-restrictive or a fast ...... conclude that oral administration of enterosoluble capsules is an easy and appropriate method for intestinal histamine challenge. Fast and histamine-restrictive diets are not necessary, but subjects should record unexpected responses in a food and symptom diary.......The study was conducted to investigate whether introduction of histamine in enterosoluble capsules produced the same amount of urinary histamine metabolites as that found after application of histamine through a duodeno-jejunal tube. Secondly, to examine whether a histamine-restrictive or a fast...... all other intervals did not differ significantly between the two challenge regimens. Fast (water only) and histamine-restrictive diet versus non-restrictive diet did not affect the urinary MIAA. MIAA was significantly higher overall during the first 24 h after challenge than in any other fraction. We...

  9. Comparison of steam generator methods in PISC

    International Nuclear Information System (INIS)

    Lahdenperae, K.; Kankare, M.

    1996-01-01

    The main objective of the study (PISC III, action 5) was the experimental evaluation of the performance of methods used in in-service inspection of steam generator tubes used in nuclear power plants. The study was organized by the Joint Research Center of the European Community (JRC). The round robin test with blind boxes started in 1991. During the study training boxes and blind boxes were circulated in 29 laboratories in Europe, Japan and the USA. The boxes contained steam generator tubes with artificial and natural (chemically induced) flaws. The material was inconell. The blind boxes contained 66 tubes and 95 flaws. All flaws were introduced into different discontinuities, under support plates, above the tube sheet and into U-bends. The flaws included volumetric flaws (wastage, pitting, wear), axial and circumferential notches and chemically induced SCC cracks and IGA. After the round robin test the reference laboratory performed the destructive examination of reported flaws. The flaw detection probability (FDP) for all flaws and for teams inspecting all tubes was 60-85%. The detection of flaws deeper than 40% of the wall thickness was good. Flaws with a depth of less than 20% were not detected. When all flaws were considered, depth sizing was found to have a wide dispersion. Similarly, measured lengths did not as a rule correlate with true lengths. The classification of flaws in cracks and of volumetric flaws was not very successful, the correct classification probability being only about 70%. Evaluation of the flaws showed some shortcomings. The correct rejection probability was at best 83% for teams inspecting all boxes. (3 refs.)

  10. Comparison of parameter-adapted segmentation methods for fluorescence micrographs.

    Science.gov (United States)

    Held, Christian; Palmisano, Ralf; Häberle, Lothar; Hensel, Michael; Wittenberg, Thomas

    2011-11-01

    Interpreting images from fluorescence microscopy is often a time-consuming task with poor reproducibility. Various image processing routines that can help investigators evaluate the images are therefore useful. The critical aspect for a reliable automatic image analysis system is a robust segmentation algorithm that can perform accurate segmentation for different cell types. In this study, several image segmentation methods were therefore compared and evaluated in order to identify the most appropriate segmentation schemes that are usable with little new parameterization and robustly with different types of fluorescence-stained cells for various biological and biomedical tasks. The study investigated, compared, and enhanced four different methods for segmentation of cultured epithelial cells. The maximum-intensity linking (MIL) method, an improved MIL, a watershed method, and an improved watershed method based on morphological reconstruction were used. Three manually annotated datasets consisting of 261, 817, and 1,333 HeLa or L929 cells were used to compare the different algorithms. The comparisons and evaluations showed that the segmentation performance of methods based on the watershed transform was significantly superior to the performance of the MIL method. The results also indicate that using morphological opening by reconstruction can improve the segmentation of cells stained with a marker that exhibits the dotted surface of cells. Copyright © 2011 International Society for Advancement of Cytometry.

  11. Comparison of Methods for Oscillation Detection

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Trangbæk, Klaus

    2006-01-01

    This paper compares a selection of methods for detecting oscillations in control loops. The methods are tested on measurement data from a coal-fired power plant, where some oscillations are occurring. Emphasis is put on being able to detect oscillations without having a system model and without...... using process knowledge. The tested methods show potential for detecting the oscillations, however, transient components in the signals cause false detections as well, motivating usage of models in order to remove the expected signals behavior....

  12. Comparison between Evapotranspiration Fluxes Assessment Methods

    Science.gov (United States)

    Casola, A.; Longobardi, A.; Villani, P.

    2009-11-01

    Knowledge of hydrological processes acting in the water balance is determinant for a rational water resources management plan. Among these, the water losses as vapour, in the form of evapotranspiration, play an important role in the water balance and the heat transfers between the land surface and the atmosphere. Mass and energy interactions between soil, atmosphere and vegetation, in fact, influence all hydrological processes modificating rainfall interception, infiltration, evapotraspiration, surface runoff and groundwater recharge.A numbers of methods have been developed in scientific literature for modelling evapotranspiration. They can be divided in three main groups: i) traditional meteorological models, ii) energy fluxes balance models, considering interaction between vegetation and the atmosphere, and iii) remote sensing based models. The present analysis preliminary performs a study of fluxes directions and an evaluation of energy balance closure in a typical Mediterranean short vegetation area, using data series recorded from an eddy covariance station, located in the Campania region, Southern Italy. The analysis was performed on different seasons of the year with the aim to assess climatic forcing features impact on fluxes balance, to evaluate the smaller imbalance and to highlight influencing factors and sampling errors on balance closure. The present study also concerns evapotranspiration fluxes assessment at the point scale. Evapotranspiration is evaluated both from empirical relationships (Penmann-Montheit, Penmann F AO, Prestley&Taylor) calibrated with measured energy fluxes at mentioned experimental site, and from measured latent heat data scaled by the latent heat of vaporization. These results are compared with traditional and reliable well known models at the plot scale (Coutagne, Turc, Thorthwaite).

  13. Comparison of dietary fiber methods for foods.

    Science.gov (United States)

    Heckman, M M; Lane, S A

    1981-11-01

    In order to evaluate several proposed dietary fiber methods, 12 food samples, representing different food classes, were analyzed by (1) neutral and acid detergent fiber methods (NDF, ADF); (2) NDF with enzyme modification (ENDF); (3) a 2-fraction enzyme method for soluble, insoluble, and total dietary fiber, proposed by Furda (SDF, IDF, TDF); (+) a 1-fraction enzyme method for total dietary fiber proposed by Hellendoorn (TDF). Foods included cereals, fruits, vegetables, pectin, locust bean gum, and soybean polysaccharides. Results show that TDF by Furda and Hellendoorn methods agree reasonably well with literature values by the Southgate method, but ENDF is consistently lower; that ENDF and IDF (Furda method) agree reasonably well; that except for corn corn bran fiber (insoluble) and pectin and locus bean fiber (soluble), all materials have significant fractions of both soluble and insoluble fiber. The Furda method was used on numerous food and ingredient samples and was found to be practical and informative and to have acceptable precision (RSD values of 2.65-7.05%). It is suggested that the Furda (or similar) method be given consideration for the analysis of foods for dietary fiber.

  14. Comparison and qualification of FFTF calorimetric methods

    International Nuclear Information System (INIS)

    McCall, T.B.; Nutt, W.T.; Zimmerman, B.D.

    1981-01-01

    The Fast Flux Test Facility achieved full power operation on December 21, 1981. During the power ascent, the reactor thermal power (calorimetric) was computed by three methods as follows: the plant main data handling computer, Plant Data System (PDS); a second computer, the Experimenter's Data System (EDS); and a manual method requiring human operator activities and a programmable calculator. It is the purpose of this paper to explain the rationale for employing the three methods, describe how each works in a schematic fashion, compare the results, and demonstrate that all methods have met stringent goals based on a statistical analysis of the results

  15. Comparison of sampling methods for animal manure

    NARCIS (Netherlands)

    Derikx, P.J.L.; Ogink, N.W.M.; Hoeksma, P.

    1997-01-01

    Currently available and recently developed sampling methods for slurry and solid manure were tested for bias and reproducibility in the determination of total phosphorus and nitrogen content of samples. Sampling methods were based on techniques in which samples were taken either during loading from

  16. Comparison of two Galerkin quadrature methods

    International Nuclear Information System (INIS)

    Morel, J. E.; Warsa, J. S.; Franke, B. C.; Prinja, A. K.

    2013-01-01

    We compare two methods for generating Galerkin quadrature for problems with highly forward-peaked scattering. In Method 1, the standard Sn method is used to generate the moment-to-discrete matrix and the discrete-to-moment is generated by inverting the moment-to-discrete matrix. In Method 2, which we introduce here, the standard Sn method is used to generate the discrete-to-moment matrix and the moment-to-discrete matrix is generated by inverting the discrete-to-moment matrix. Method 1 has the advantage that it preserves both N eigenvalues and N eigenvectors (in a pointwise sense) of the scattering operator with an N-point quadrature. Method 2 has the advantage that it generates consistent angular moment equations from the corresponding S N equations while preserving N eigenvalues of the scattering operator with an N-point quadrature. Our computational results indicate that these two methods are quite comparable for the test problem considered. (authors)

  17. COMPARISON OF TWO METHODS FOR THE DETECTION OF LISTERIA MONOCYTOGENES

    Directory of Open Access Journals (Sweden)

    G. Tantillo

    2013-02-01

    Full Text Available The aim of this study was to compare the performance of the conventional methods for detection of Listeria monocytogenes in food using media Oxford and ALOA (Agar Listeria acc. to Ottaviani & Agosti in according to the ISO 11290-1 to a new chromogenic medium “CHROMagar Listeria” standardized in 2005 AFNOR ( CHR – 21/1-12/01. A total of 40 pre-packed ready-to-eat food samples were examined. Using two methods six samples were found positive for Listeria monocytogenes but the medium “CHROMagar Listeria” was more selective in comparison with the others. In conclusion this study has demonstrated that isolation medium able to target specifically the detection of L. monocytogenes such as “CHROMagar Listeria” is highly recommendable because of that detection time is significantly reduced and the analysis cost is less expensive.

  18. How to find non-dependent opiate users: a comparison of sampling methods in a field study of opium and heroin users

    NARCIS (Netherlands)

    Korf, D.J.; van Ginkel, P.; Benschop, A.

    2010-01-01

    Background/aim The first aim is to better understand the potentials and limitations of different sampling methods for reaching a specific, rarely studied population of drug users and for persuading them to take part in a multidisciplinary study. The second is to determine the extent to which these

  19. A contribution to the study of pyrogenic substances in radiopharmaceutical preparations. Comparison between methods using Rabbit and those using Limulus amebocytes lysate

    International Nuclear Information System (INIS)

    Bruneau, Jacky.

    1982-10-01

    We have studied two methods for pyrogenic substances detection. We used: the hyperthermic action of these substances after injection in Rabbit, and the gelation reaction of a Limulus amebocytes lysate. To apply these two methods of pyrogenic substances detection to the radiopharmaceutical preparations, we have conceived and designed a material allowing their handling in compliance with the radioactive safety norms. We have compared the sensitivity, reliability and reproducibility of these methods, one based on gelation of Limulus amebocytes lysate in presence of endotoxins, the other on the hyperthermic action of these same endotoxins in the rabbit when injected intravenously or through the suboccipital route. The discussion of the results obtained, shows that the method using the Limulus amebocytes lysate is more sensitive, less expansive and less dangerous. This method particulary well adapted to the control of radiopharmaceutical preparations, brings an additional security to the patients for whom these products are destined [fr

  20. Comparison of the direct enzyme assay method with the membrane ...

    African Journals Online (AJOL)

    Comparison of the direct enzyme assay method with the membrane filtration technique in the quantification and monitoring of microbial indicator organisms – seasonal variations in the activities of coliforms and E. coli, temperature and pH.

  1. Comparison of two methods for customer differentiation

    NARCIS (Netherlands)

    A.F. Gabor (Adriana); Y. Guang (Yang); S. Axsäter (Sven)

    2014-01-01

    textabstractIn response to customer specific time guarantee requirements, service providers can offer differentiated ser- vices. However, conventional customer differentiation methods often lead to high holding costs and may have some practical drawbacks. We compare two customer differentiation

  2. Comparison of seven optical clearing methods for mouse brain

    Science.gov (United States)

    Wan, Peng; Zhu, Jingtan; Yu, Tingting; Zhu, Dan

    2018-02-01

    Recently, a variety of tissue optical clearing techniques have been developed to reduce light scattering for imaging deeper and three-dimensional reconstruction of tissue structures. Combined with optical imaging techniques and diverse labeling methods, these clearing methods have significantly promoted the development of neuroscience. However, most of the protocols were proposed aiming for specific tissue type. Though there are some comparison results, the clearing methods covered are limited and the evaluation indices are lack of uniformity, which made it difficult to select a best-fit protocol for clearing in practical applications. Hence, it is necessary to systematically assess and compare these clearing methods. In this work, we evaluated the performance of seven typical clearing methods, including 3DISCO, uDISCO, SeeDB, ScaleS, ClearT2, CUBIC and PACT, on mouse brain samples. First, we compared the clearing capability on both brain slices and whole-brains by observing brain transparency. Further, we evaluated the fluorescence preservation and the increase of imaging depth. The results showed that 3DISCO, uDISCO and PACT posed excellent clearing capability on mouse brains, ScaleS and SeeDB rendered moderate transparency, while ClearT2 was the worst. Among those methods, ScaleS was the best on fluorescence preservation, and PACT achieved the highest increase of imaging depth. This study is expected to provide important reference for users in choosing most suitable brain optical clearing method.

  3. A Comparison of Distillery Stillage Disposal Methods

    OpenAIRE

    V. Sajbrt; M. Rosol; P. Ditl

    2010-01-01

    This paper compares the main stillage disposal methods from the point of view of technology, economics and energetics. Attention is paid to the disposal of both solid and liquid phase. Specifically, the following methods are considered: a) livestock feeding, b) combustion of granulated stillages, c) fertilizer production, d) anaerobic digestion with biogas production and e) chemical pretreatment and subsequent secondary treatment. Other disposal techniques mentioned in the literature (electro...

  4. A comparison of two instructional methods for drawing Lewis Structures

    Science.gov (United States)

    Terhune, Kari

    Two instructional methods for teaching Lewis structures were compared -- the Direct Octet Rule Method (DORM) and the Commonly Accepted Method (CAM). The DORM gives the number of bonds and the number of nonbonding electrons immediately, while the CAM involves moving electron pairs from nonbonding to bonding electrons, if necessary. The research question was as follows: Will high school chemistry students draw more accurate Lewis structures using the DORM or the CAM? Students in Regular Chemistry 1 (N = 23), Honors Chemistry 1 (N = 51) and Chemistry 2 (N = 15) at an urban high school were the study participants. An identical pretest and posttest was given before and after instruction. Students were given instruction with either the DORM (N = 45), the treatment method, or the CAM (N = 44), the control for two days. After the posttest, 15 students were interviewed, using a semistructured interview process. The pretest/posttest consisted of 23 numerical response questions and 2 to 6 free response questions that were graded using a rubric. A two-way ANOVA showed a significant interaction effect between the groups and the methods, F (1, 70) = 10.960, p = 0.001. Post hoc comparisons using the Bonferroni pairwise comparison showed that Reg Chem 1 students demonstrated larger gain scores when they had been taught the CAM (Mean difference = 3.275, SE = 1.324, p Chemistry 1 students performed better with the DORM, perhaps due to better math skills, enhanced working memory, and better metacognitive skills. Regular Chemistry 1 students performed better with the CAM, perhaps because it is more visual. Teachers may want to use the CAM or a direct-pairing method to introduce the topic and use the DORM in advanced classes when a correct structure is needed quickly.

  5. Comparison of Standard and Fast Charging Methods for Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Petr Chlebis

    2014-01-01

    Full Text Available This paper describes a comparison of standard and fast charging methods used in the field of electric vehicles and also comparison of their efficiency in terms of electrical energy consumption. The comparison was performed on three-phase buck converter, which was designed for EV’s fast charging station. The results were obtained by both mathematical and simulation methods. The laboratory model of entire physical application, which will be further used for simulation results verification, is being built in these days.

  6. Comparison of gestational dating methods and implications ...

    Science.gov (United States)

    OBJECTIVES: Estimating gestational age is usually based on date of last menstrual period (LMP) or clinical estimation (CE); both approaches introduce potential bias. Differences in methods of estimation may lead to misclassificat ion and inconsistencies in risk estimates, particularly if exposure assignment is also gestation-dependent. This paper examines a'what-if' scenario in which alternative methods are used and attempts to elucidate how method choice affects observed results.METHODS: We constructed two 20-week gestational age cohorts of pregnancies between 2000 and 2005 (New Jersey, Pennsylvania, Ohio, USA) using live birth certificates : one defined preterm birth (PTB) status using CE and one using LMP. Within these, we estimated risk for 4 categories of preterm birth (PTBs per 106 pregnancies) and risk differences (RD (95% Cl s)) associated with exposure to particulate matter (PM2. 5).RESULTS: More births were classified preterm using LMP (16%) compared with CE (8%). RD divergences increased between cohorts as exposure period approached delivery. Among births between 28 and 31 weeks, week 7 PM2.5 exposure conveyed RDs of 44 (21 to 67) for CE and 50 (18 to 82) for LMP populations, while week 24 exposure conveyed RDs of 33 (11 to 56) and -20 (-50 to 10), respectively.CONCLUSIONS: Different results from analyses restricted to births with both CE and LMP are most likely due to differences in dating methods rather than selection issues. Results are sensitive t

  7. Comparison of meaningful learning characteristics in simulated nursing practice after traditional versus computer-based simulation method: a qualitative videography study.

    Science.gov (United States)

    Poikela, Paula; Ruokamo, Heli; Teräs, Marianne

    2015-02-01

    Nursing educators must ensure that nursing students acquire the necessary competencies; finding the most purposeful teaching methods and encouraging learning through meaningful learning opportunities is necessary to meet this goal. We investigated student learning in a simulated nursing practice using videography. The purpose of this paper is to examine how two different teaching methods presented students' meaningful learning in a simulated nursing experience. The 6-hour study was divided into three parts: part I, general information; part II, training; and part III, simulated nursing practice. Part II was delivered by two different methods: a computer-based simulation and a lecture. The study was carried out in the simulated nursing practice in two universities of applied sciences, in Northern Finland. The participants in parts II and I were 40 first year nursing students; 12 student volunteers continued to part III. Qualitative analysis method was used. The data were collected using video recordings and analyzed by videography. The students who used a computer-based simulation program were more likely to report meaningful learning themes than those who were first exposed to lecture method. Educators should be encouraged to use computer-based simulation teaching in conjunction with other teaching methods to ensure that nursing students are able to receive the greatest educational benefits. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Comparison of some nonlinear smoothing methods

    International Nuclear Information System (INIS)

    Bell, P.R.; Dillon, R.S.

    1977-01-01

    Due to the poor quality of many nuclear medicine images, computer-driven smoothing procedures are frequently employed to enhance the diagnostic utility of these images. While linear methods were first tried, it was discovered that nonlinear techniques produced superior smoothing with little detail suppression. We have compared four methods: Gaussian smoothing (linear), two-dimensional least-squares smoothing (linear), two-dimensional least-squares bounding (nonlinear), and two-dimensional median smoothing (nonlinear). The two dimensional least-squares procedures have yielded the most satisfactorily enhanced images, with the median smoothers providing quite good images, even in the presence of widely aberrant points

  9. Comparison of two methods of preparation of tissue to study the internal anatomy of the delphacid Togosodes orizicolus with microscopy of electronic light

    International Nuclear Information System (INIS)

    Macaya-Lizano, A.V.; Pereira, R.; Espinoza, A.M.

    1997-01-01

    Two methods of embedding, sectioning and staining were developed to study the internal anatomy of delphacid plant hopper Tagosodes orizicolus, one of the most important plagues of rice in Latin America and the only vector of the white leaf tenuivirus (RHBV), using both light and electron microscopy. The paraffines-hematoxyline-eosin Y method allows color identification of tissues, for example purple for fat tissue, pink for muscles, yellow-brown for exocutile, while the resin-toluidine-blue method preserves better the ultrastructure but do not permit color identification. The information obtained by these procedures is complementary and the material can also be used for in situ studies by immuno microscopy, to assess the changes in cell ultrastructure and the localization and replication of the RHBV during its infection cycle in the insect vector. (author) [es

  10. Comparison of power curve monitoring methods

    Directory of Open Access Journals (Sweden)

    Cambron Philippe

    2017-01-01

    Full Text Available Performance monitoring is an important aspect of operating wind farms. This can be done through the power curve monitoring (PCM of wind turbines (WT. In the past years, important work has been conducted on PCM. Various methodologies have been proposed, each one with interesting results. However, it is difficult to compare these methods because they have been developed using their respective data sets. The objective of this actual work is to compare some of the proposed PCM methods using common data sets. The metric used to compare the PCM methods is the time needed to detect a change in the power curve. Two power curve models will be covered to establish the effect the model type has on the monitoring outcomes. Each model was tested with two control charts. Other methodologies and metrics proposed in the literature for power curve monitoring such as areas under the power curve and the use of statistical copulas have also been covered. Results demonstrate that model-based PCM methods are more reliable at the detecting a performance change than other methodologies and that the effectiveness of the control chart depends on the types of shift observed.

  11. Differential and difference equations a comparison of methods of solution

    CERN Document Server

    Maximon, Leonard C

    2016-01-01

    This book, intended for researchers and graduate students in physics, applied mathematics and engineering, presents a detailed comparison of the important methods of solution for linear differential and difference equations - variation of constants, reduction of order, Laplace transforms and generating functions - bringing out the similarities as well as the significant differences in the respective analyses. Equations of arbitrary order are studied, followed by a detailed analysis for equations of first and second order. Equations with polynomial coefficients are considered and explicit solutions for equations with linear coefficients are given, showing significant differences in the functional form of solutions of differential equations from those of difference equations. An alternative method of solution involving transformation of both the dependent and independent variables is given for both differential and difference equations. A comprehensive, detailed treatment of Green’s functions and the associat...

  12. Comparison of three sensory profiling methods based on consumer perception

    DEFF Research Database (Denmark)

    Reinbach, Helene Christine; Giacalone, Davide; Ribeiro, Letícia Machado

    2014-01-01

    The present study compares three profiling methods based on consumer perceptions in their ability to discriminate and describe eight beers. Consumers (N=135) evaluated eight different beers using Check-All-That-Apply (CATA) methodology in two variations, with (n=63) and without (n=73) rating...... the intensity of the checked descriptors. With CATA, consumers rated 38 descriptors grouped in 7 overall categories (berries, floral, hoppy, nutty, roasted, spicy/herbal and woody). Additionally 40 of the consumers evaluated the same samples by partial Napping® followed by Ultra Flash Profiling (UFP). ANOVA...... comparisons the RV coefficients varied between 0.90 and 0.97, indicating a very high similarity between all three methods. These results show that the precision and reproducibility of sensory information obtained by consumers by CATA is comparable to that of Napping. The choice of methodology for consumer...

  13. Comparison of support vector machine and neutral network classification method in hyperspectral mapping of ophiolite mélanges–A case study of east of Iran

    Directory of Open Access Journals (Sweden)

    Bahram Bahrambeygi

    2017-06-01

    Full Text Available Ophiolitic regions are one of the most complex geology settings. Mapping in these parts need broad and precise studies and tools because of the mixture rocks and confusion units. Hyperion hyperspectral sensor data are one of the advanced tools for earth surface mapping that containing rich information of shallow electromagnetic reflection in 242 continuous bands. Because of some contaminated noise in tens of these bands we removed 87 most noisy bands and focused our study on 155 low noisy bands. In present study, tow spectral based classification algorithms of support vector machine and neutral network are compared on hyperion image for classification of cluttered units in an ophiolite set. Study area is Mesina region in collision ophiolitic belt of south east of Iran. In this region for design processing results validation rate, lots of random locations and control points were studied in field scale and were sampled for laboratory surveys. Samples were investigated in microscopic section and by electron microprobe system. Based on laboratory-field studies, the lithology of this area can divided into five general groups: (Melange series, metamorphic units, Oligocene – Miocene to Quaternary volcanic units, lime and flysch units. Based on field-laboratory works, some standard points defined for validate processing results accuracy rate. Therefore, the Support Vector Machine and neutral network method as advanced hyperspectral image processing methods respectively have overall accuracies of 52% and 65%. Consequently the method based neutral network theory for hyperspectral classification have acceptable ratio in separation of blended complicated units.

  14. [Comparison of surface light scattering of acrylic intraocular lenses made by lathe-cutting and cast-molding methods--long-term observation and experimental study].

    Science.gov (United States)

    Nishihara, Hitoshi; Ayaki, Masahiko; Watanabe, Tomiko; Ohnishi, Takeo; Kageyama, Toshiyuki; Yaguchi, Shigeo

    2004-03-01

    To compare the long-term clinical and experimental results of soft acrylic intraocular lenses(IOLs) manufactured by the lathe-cut(LC) method and by the cast-molding(CM) method. This was a retrospective study of 20 patients(22 eyes) who were examined in a 5- and 7-year follow-up study. Sixteen eyes were implanted with polyacrylic IOLs manufactured by the LC method and 6 eyes were implanted with polyacrylic IOLs manufactured by the CM method. Postoperative measurements included best corrected visual acuity, contrast sensitivity, biomicroscopic examination, and Scheimpflug slit-lamp images to evaluate surface light scattering. Scanning electron microscopy and three-dimensional surface analysis were conducted. At 7 years, the mean visual acuity was 1.08 +/- 0.24 (mean +/- standard deviation) in the LC group and 1.22 +/- 0.27 in the CM group. Surface light-seatter was 12.0 +/- 4.0 computer compatible tapes(CCT) in the LC group and 37.4 +/- 5.4 CCT in the CM group. Mean surface roughness was 0.70 +/- 0.07 nm in the LC group and 6.16 +/- 0.97 nm in the CM group. Acrylic IOLs manufactured by the LC method are more stable in long-termuse.

  15. Comparison of five DNA quantification methods

    DEFF Research Database (Denmark)

    Nielsen, Karsten; Mogensen, Helle Smidt; Hedman, Johannes

    2008-01-01

    Six commercial preparations of human genomic DNA were quantified using five quantification methods: UV spectrometry, SYBR-Green dye staining, slot blot hybridization with the probe D17Z1, Quantifiler Human DNA Quantification kit and RB1 rt-PCR. All methods measured higher DNA concentrations than...... Quantification kit in two experiments. The measured DNA concentrations with Quantifiler were 125 and 160% higher than expected based on the manufacturers' information. When the Quantifiler human DNA standard (Raji cell line) was replaced by the commercial human DNA preparation G147A (Promega) to generate the DNA...... standard curve in the Quantifiler Human DNA Quantification kit, the DNA quantification results of the human DNA preparations were 31% higher than expected based on the manufacturers' information. The results indicate a calibration problem with the Quantifiler human DNA standard for its use...

  16. A comparison of methods for cascade prediction

    OpenAIRE

    Guo, Ruocheng; Shakarian, Paulo

    2016-01-01

    Information cascades exist in a wide variety of platforms on Internet. A very important real-world problem is to identify which information cascades can go viral. A system addressing this problem can be used in a variety of applications including public health, marketing and counter-terrorism. As a cascade can be considered as compound of the social network and the time series. However, in related literature where methods for solving the cascade prediction problem were proposed, the experimen...

  17. Comparison of testing methods for particulate filters

    International Nuclear Information System (INIS)

    Ullmann, W.; Przyborowski, S.

    1983-01-01

    Four testing methods for particulate filters were compared by using the test rigs of the National Board of Nuclear Safety and Radiation Protection: 1) Measurement of filter penetration P as a function of particle size d by using a polydisperse NaC1 test aerosol and a scintillation particle counter; 2) Modified sodium flame test for measurement of total filter penetration P for various polydisperse NaC1 test aerosols; 3) Measurement of total filter penetration P for a polydisperse NaC1 test aerosol labelled with short-lived radon daughter products; 4) Measurement of total filter penetration P for a special paraffin oil test aerosol (oil fog test used in FRG according DIN 24 184, test aerosol A). The investigations were carried out on sheets of glass fibre paper (five grades of paper). Detailed information about the four testing methods and the used particle size distributions is given. The different results of the various methods are the base for the discussion of the most important parameters which influence the filter penetration P. The course of the function P=f(d) shows the great influence of the particle size. As expected there was also found a great dependence both from the test aerosol as well as from the principle and the measuring range of the aerosol-measuring device. The differences between the results of the various test methods are greater the lower the penetration. The use of NaCl test aerosol with various particle size distributions gives great differences for the respective penetration values. On the basis of these results and the values given by Dorman conclusions are made about the investigation of particulate filters both for the determination of filter penetration P as well as for the leak test of installed filters

  18. Comparison of methods for estimating premorbid intelligence

    OpenAIRE

    Bright, Peter; van der Linde, Ian

    2018-01-01

    To evaluate impact of neurological injury on cognitive performance it is typically necessary to derive a baseline (or ‘premorbid’) estimate of a patient’s general cognitive ability prior to the onset of impairment. In this paper, we consider a range of common methods for producing this estimate, including those based on current best performance, embedded ‘hold/no hold’ tests, demographic information, and word reading ability. Ninety-two neurologically healthy adult participants were assessed ...

  19. COMPARISON OF DIGITAL IMAGE STEGANOGRAPHY METHODS

    Directory of Open Access Journals (Sweden)

    S. A. Seyyedi

    2013-01-01

    Full Text Available Steganography is a method of hiding information in other information of different format (container. There are many steganography techniques with various types of container. In the Internet, digital images are the most popular and frequently used containers. We consider main image steganography techniques and their advantages and disadvantages. We also identify the requirements of a good steganography algorithm and compare various such algorithms.

  20. Comparison of methods for calculating decay lifetimes

    International Nuclear Information System (INIS)

    Tobocman, W.

    1978-01-01

    A simple scattering model is used to test alternative methods for calculating decay lifetimes, or equivalently, resonance widths. We consider the scattering of s-wave particles by a square well with a square barrier. Exact values for resonance energies and resonance widths are compared with values calculated from Wigner-Weisskopf perturbation theory and from the Garside-MacDonald projection operator formalism. The Garside-MacDonald formalism gives essentially exact results while the predictions of the Wigner-Weisskopf formalism are fairly poor

  1. Comparison of the functionality of pelvic floor muscles in women who practice the Pilates method and sedentary women: a pilot study.

    Science.gov (United States)

    Ferla, Lia; Paiva, Luciana Laureano; Darki, Caroline; Vieira, Adriane

    2016-01-01

    The Pilates method is a form of physical exercise that improves the control of the core muscles, improving the conditioning of all the muscle groups that comprise the core, including the pelvic floor muscles (PFM). Thus, this study had the goal of verifying the existence of differences in the functioning of the PFM in women who practice the Pilates method and sedentary women. This was an observational, cross-sectional pilot study. A sample size calculation was performed using preliminary data and it determined that the sample should have at least 24 individuals in each group. The participants were 60 women aged 20 to 40 years; 30 women practiced the Pilates method (PMG) and 30 were sedentary (SG). An anamnesis file was used to collect personal data and assess the knowledge and perception of the PFM. The Perina perineometer and vaginal palpation were used to determine the functionality of the PFM. There was no significant difference between the PMG and the SG in any of the variables analyzed. We concluded that the functionality of the PFM in younger women who practice the Pilates method is not different from that of sedentary women.

  2. Comparison of accounting methods for business combinations

    Directory of Open Access Journals (Sweden)

    Jaroslav Sedláček

    2012-01-01

    Full Text Available The revised accounting rules applicable to business combinations in force on July1st 2009, are the result of several years efforts the convergence of U.S. and International Committee of the Financial Accounting Standards. Following the harmonization of global accounting procedures are revised and implemented also Czech accounting regulations. In our research we wanted to see how changes can affect the strategy and timing of business combinations. Comparative analysis is mainly focused on the differences between U.S. and international accounting policies and Czech accounting regulations. Key areas of analysis and synthesis are the identification of business combination, accounting methods for business combinations and goodwill recognition. The result is to assess the impact of the identified differences in the reported financial position and profit or loss of company.

  3. Comparison of microstickies measurement methods. Part I, sample preparation and measurement methods

    Science.gov (United States)

    Mahendra R. Doshi; Angeles Blanco; Carlos Negro; Gilles M. Dorris; Carlos C. Castro; Axel Hamann; R. Daniel Haynes; Carl Houtman; Karen Scallon; Hans-Joachim Putz; Hans Johansson; R.A. Venditti; K. Copeland; H.-M. Chang

    2003-01-01

    Recently, we completed a project on the comparison of macrostickies measurement methods. Based on the success of the project, we decided to embark on this new project on comparison of microstickies measurement methods. When we started this project, there were some concerns and doubts principally due to the lack of an accepted definition of microstickies. However, we...

  4. An interactive website for analytical method comparison and bias estimation.

    Science.gov (United States)

    Bahar, Burak; Tuncel, Ayse F; Holmes, Earle W; Holmes, Daniel T

    2017-12-01

    Regulatory standards mandate laboratories to perform studies to ensure accuracy and reliability of their test results. Method comparison and bias estimation are important components of these studies. We developed an interactive website for evaluating the relative performance of two analytical methods using R programming language tools. The website can be accessed at https://bahar.shinyapps.io/method_compare/. The site has an easy-to-use interface that allows both copy-pasting and manual entry of data. It also allows selection of a regression model and creation of regression and difference plots. Available regression models include Ordinary Least Squares, Weighted-Ordinary Least Squares, Deming, Weighted-Deming, Passing-Bablok and Passing-Bablok for large datasets. The server processes the data and generates downloadable reports in PDF or HTML format. Our website provides clinical laboratories a practical way to assess the relative performance of two analytical methods. Copyright © 2017 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  5. Comparison of sine dwell and broadband methods for modal testing

    Science.gov (United States)

    Chen, Jay-Chung

    1989-01-01

    The objectives of modal tests for large complex spacecraft structural systems are outlined. The comparison criteria for the modal test methods, namely, the broadband excitation and the sine dwell methods, are established. Using the Galileo spacecraft modal test and the Centaur G Prime upper stage vehicle modal test as examples, the relative advantage or disadvantage of each method is examined. The usefulness or shortcomings of the methods are given from a practical engineering viewpoint.

  6. Comparison of genetic algorithms with conjugate gradient methods

    Science.gov (United States)

    Bosworth, J. L.; Foo, N. Y.; Zeigler, B. P.

    1972-01-01

    Genetic algorithms for mathematical function optimization are modeled on search strategies employed in natural adaptation. Comparisons of genetic algorithms with conjugate gradient methods, which were made on an IBM 1800 digital computer, show that genetic algorithms display superior performance over gradient methods for functions which are poorly behaved mathematically, for multimodal functions, and for functions obscured by additive random noise. Genetic methods offer performance comparable to gradient methods for many of the standard functions.

  7. Comparison of Address-based Sampling and Random-digit Dialing Methods for Recruiting Young Men as Controls in a Case-Control Study of Testicular Cancer Susceptibility

    OpenAIRE

    Clagett, Bartholt; Nathanson, Katherine L.; Ciosek, Stephanie L.; McDermoth, Monique; Vaughn, David J.; Mitra, Nandita; Weiss, Andrew; Martonik, Rachel; Kanetsky, Peter A.

    2013-01-01

    Random-digit dialing (RDD) using landline telephone numbers is the historical gold standard for control recruitment in population-based epidemiologic research. However, increasing cell-phone usage and diminishing response rates suggest that the effectiveness of RDD in recruiting a random sample of the general population, particularly for younger target populations, is decreasing. In this study, we compared landline RDD with alternative methods of control recruitment, including RDD using cell-...

  8. Comparison of nuclear analytical methods with competitive methods

    International Nuclear Information System (INIS)

    1987-10-01

    The use of nuclear analytical techniques, especially neutron activation analysis, already have a 50 year old history. Today several sensitive and accurate, non-nuclear trace element analytical techniques are available and new methods are continuously developed. The IAEA is supporting the development of nuclear analytical laboratories in its Member States. In order to be able to advise the developing countries which methods to use in different applications, it is important to know the present status and development trends of nuclear analytical methods, what are their benefits, drawbacks and recommended fields of application, compared with other, non-nuclear techniques. In order to get an answer to these questions the IAEA convened this Advisory Group Meeting. This volume is the outcome of the presentations and discussions of the meeting. A separate abstract was prepared for each of the 21 papers. Refs, figs, tabs

  9. Evaluation and Comparison of the Processing Methods of Airborne Gravimetry Concerning the Errors Effects on Downward Continuation Results: Case Studies in Louisiana (USA) and the Tibetan Plateau (China).

    Science.gov (United States)

    Zhao, Qilong; Strykowski, Gabriel; Li, Jiancheng; Pan, Xiong; Xu, Xinyu

    2017-05-25

    Gravity data gaps in mountainous areas are nowadays often filled in with the data from airborne gravity surveys. Because of the errors caused by the airborne gravimeter sensors, and because of rough flight conditions, such errors cannot be completely eliminated. The precision of the gravity disturbances generated by the airborne gravimetry is around 3-5 mgal. A major obstacle in using airborne gravimetry are the errors caused by the downward continuation. In order to improve the results the external high-accuracy gravity information e.g., from the surface data can be used for high frequency correction, while satellite information can be applying for low frequency correction. Surface data may be used to reduce the systematic errors, while regularization methods can reduce the random errors in downward continuation. Airborne gravity surveys are sometimes conducted in mountainous areas and the most extreme area of the world for this type of survey is the Tibetan Plateau. Since there are no high-accuracy surface gravity data available for this area, the above error minimization method involving the external gravity data cannot be used. We propose a semi-parametric downward continuation method in combination with regularization to suppress the systematic error effect and the random error effect in the Tibetan Plateau; i.e., without the use of the external high-accuracy gravity data. We use a Louisiana airborne gravity dataset from the USA National Oceanic and Atmospheric Administration (NOAA) to demonstrate that the new method works effectively. Furthermore, and for the Tibetan Plateau we show that the numerical experiment is also successfully conducted using the synthetic Earth Gravitational Model 2008 (EGM08)-derived gravity data contaminated with the synthetic errors. The estimated systematic errors generated by the method are close to the simulated values. In addition, we study the relationship between the downward continuation altitudes and the error effect. The

  10. Evaluation and Comparison of the Processing Methods of Airborne Gravimetry Concerning the Errors Effects on Downward Continuation Results: Case Studies in Louisiana (USA) and the Tibetan Plateau (China)

    Science.gov (United States)

    Zhao, Q.

    2017-12-01

    Gravity data gaps in mountainous areas are nowadays often filled in with the data from airborne gravity surveys. Because of the errors caused by the airborne gravimeter sensors, and because of rough flight conditions, such errors cannot be completely eliminated. The precision of the gravity disturbances generated by the airborne gravimetry is around 3-5 mgal. A major obstacle in using airborne gravimetry are the errors caused by the downward continuation. In order to improve the results the external high-accuracy gravity information e.g., from the surface data can be used for high frequency correction, while satellite information can be applying for low frequency correction. Surface data may be used to reduce the systematic errors, while regularization methods can reduce the random errors in downward continuation. Airborne gravity surveys are sometimes conducted in mountainous areas and the most extreme area of the world for this type of survey is the Tibetan Plateau. Since there are no high-accuracy surface gravity data available for this area, the above error minimization method involving the external gravity data cannot be used. We propose a semi-parametric downward continuation method in combination with regularization to suppress the systematic error effect and the random error effect in the Tibetan Plateau; i.e., without the use of the external high-accuracy gravity data. We use a Louisiana airborne gravity dataset from the USA National Oceanic and Atmospheric Administration (NOAA) to demonstrate that the new method works effectively. Furthermore, and for the Tibetan Plateau we show that the numerical experiment is also successfully conducted using the synthetic Earth Gravitational Model 2008 (EGM08)-derived gravity data contaminated with the synthetic errors. The estimated systematic errors generated by the method are close to the simulated values. In addition, we study the relationship between the downward continuation altitudes and the error effect. The

  11. Comparison of different methods for thoron progeny measurement

    International Nuclear Information System (INIS)

    Bi Lei; Zhu Li; Shang Bing; Cui Hongxing; Zhang Qingzhao

    2009-01-01

    Four popular methods for thoron progeny measurement were discussed, including the aspects of detector,principle, precondition, calculation advantages and disadvantages. Comparison experiments were made in mine and houses with high background in Yunnan Province. Since indoor thoron progeny changes with time obviously and with no rule, α track method is recommended in the area of radiation protection for environmental detection and assessment. (authors)

  12. Comparison of estimation methods for fitting weibull distribution to ...

    African Journals Online (AJOL)

    Comparison of estimation methods for fitting weibull distribution to the natural stand of Oluwa Forest Reserve, Ondo State, Nigeria. ... Journal of Research in Forestry, Wildlife and Environment ... The result revealed that maximum likelihood method was more accurate in fitting the Weibull distribution to the natural stand.

  13. Sperm Na+, K+-ATPase and Ca2+-ATPase activity: A preliminary study of comparison of swim up and density gradient centrifugation methods for sperm preparation

    Science.gov (United States)

    Lestari, Silvia W.; Larasati, Manggiasih D.; Asmarinah, Mansur, Indra G.

    2018-02-01

    As one of the treatment for infertility, the success rate of Intrauterine Insemination (IUI) is still relatively low. Several sperm preparation methods, swim-up (SU) and the density-gradient centrifugation (DGC) are frequently used to select for better sperm quality which also contribute to IUI failure. Sperm selection methods mainly separate the motile from the immotile sperm, eliminating the seminal plasma. The sperm motility involves the structure and function of sperm membrane in maintaining the balance of ion transport system which is regulated by the Na+, K+-ATPase, and Ca2+-ATPase enzymes. This study aims to re-evaluate the efficiency of these methods in selecting for sperm before being used for IUI and based the evaluation on sperm Na+,K+-ATPase and Ca2+-ATPase activities. Fourteen infertile men from couples who underwent IUI were involved in this study. The SU and DGC methods were used for the sperm preparation. Semen analysis was performed based on the reference value of World Health Organization (WHO) 2010. After isolating the membrane fraction of sperms, the Na+, K+-ATPase activity was defined as the difference in the released inorganic phosphate (Pi) with and without the existence of 10 mM ouabain in the reaction, while the Ca2+-ATPase was determined as the difference in Pi contents with and without the existence of 55 µm CaCl2. The prepared sperm demonstrated a higher percentage of motile sperm compared to sperm from the whole semen. Additionally, the percentage of motile sperm of post-DGC showed higher result than the sperm from post-SU. The velocity of sperm showed similar pattern with the percentage of motile sperm, in which the velocity of prepared sperm was higher than the sperm from whole semen. Furthermore, the sperm velocity of post-DGC was higher compared to the sperm from post-SU. The Na+, K+-ATPase activity of prepared sperm was higher compared to whole semen, whereas Na+, K+-ATPase activity in the post DGC was higher than post SU. The Ca2

  14. Comparison of methods for identifying small-for-gestational-age infants at risk of perinatal mortality among obese mothers: a hospital-based cohort study.

    Science.gov (United States)

    Hinkle, S N; Sjaarda, L A; Albert, P S; Mendola, P; Grantz, K L

    2016-11-01

    To assess differences in small-for-gestational age (SGA) classifications for the detection of neonates with increased perinatal mortality risk among obese women and subsequently assess the association between prepregnancy body mass index (BMI) status and SGA. Hospital-based cohort. Twelve US clinical centres (2002-08). A total of 114 626 singleton, nonanomalous pregnancies. Data were collected using electronic medical record abstraction. Relative risks (RR) with 95% CI were estimated. SGA trends (birthweight < 10th centile) classified using population-based (SGA POP ), intrauterine (SGA IU ) and customised (SGA CUST ) references were assessed. The SGA-associated perinatal mortality risk was estimated among obese women. Using the SGA method most associated with perinatal mortality, the association between prepregnancy BMI and SGA was estimated. The overall perinatal mortality prevalence was 0.55% and this increased significantly with increasing BMI (P < 0.01). Among obese women, SGA IU detected the highest proportion of perinatal mortality cases (2.49%). Perinatal mortality was 5.32 times (95% CI 3.72-7.60) more likely among SGA IU neonates than non-SGA IU neonates. This is in comparison with the 3.71-fold (2.49-5.53) and 4.81-fold (3.41-6.80) increased risk observed when SGA POP and SGA CUST were used, respectively. Compared with women of normal weight, overweight women (RR = 0.82, 95% CI 0.78-0.86) and obese women (RR = 0.80; 95% CI 0.75-0.83) had a lower risk for delivering an SGA IU neonate. Among obese women, the intrauterine reference best identified neonates at risk of perinatal mortality. Based on SGA IU , SGA is less common among obese women but these SGA babies are at a high risk of death and remain an important group for surveillance. SGA is less common among obese women but these SGA babies are at a high risk of death. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

  15. Comparison of whole-body-imaging methods

    International Nuclear Information System (INIS)

    Rollo, F.D.; Hoffer, P.

    1977-01-01

    Currently there are four different devices that have found clinical utility in whole-body imaging. These are the rectilinear scanner, the multicrystal whole-body scanner, the Anger-type camera with a whole-body-imaging table, and the tomoscanner. In this text, the basic theory of operation and a discussion of the advantages and disadvantages in whole-body imaging is presented for each device. When applicable, a comparative assessment of the various devices is also presented. As with all else in life, there is no simple answer to the question ''which total body imaging device is best.'' Institutions with a very heavy total-body-imaging load may prefer to use an already available dual-headed rectilinear scanner system for these studies, rather than invest in a new instrument. Institutions with moderate total-body-imaging loads may wish to invest in moving table or moving camera devices which make total body imaging more convenient but retain the basic flexibility of the camera. The large-field Anger camera with or without motion offers another flexible option to these institutions. The laboratory with a very heavy total body imaging load may select efficiency over flexibility, thereby freeing up other instruments for additional studies. Finally, reliability as well as availability and quality of local service must be considered. After all, design features of an instrument become irrelevant when it is broken down and awaiting repair

  16. Comparison Study to the Use of Geophysical Methods at Archaeological Sites Observed by Various Remote Sensing Techniques in the Czech Republic

    Directory of Open Access Journals (Sweden)

    Roman Křivánek

    2017-09-01

    Full Text Available A combination of geophysical methods could be very a useful and a practical way of verifying the origin and precise localisation of archaeological situations identified by different remote sensing techniques. The results of different methods (and scales of monitoring these fully non-destructive methods provide distinct data and often complement each other. The presented examples of combinations of these methods/techniques in this study (aerial survey, LIDAR-ALS and surface magnetometer or resistivity survey could provide information on some specifics and may also be limitations in surveying different archaeological terrains, types of archaeological situations and activities. The archaeological site in this contribution is considered to be a material of this study. In case of Neolithic ditch enclosure near Kolín were compared aerial prospection data, magnetometer survey and aerial photo-documentation of excavated site. In the case of hillforts near Levousy we compared LIDAR data with aerial photography and large-scale magnetometer survey. In the case of the medieval castle Liběhrad we compared LIDAR data with geoelectric resistivity measurement. In case of a burial mound cemetery we combined LIDAR data with magnetometer survey. In the case of the production area near Rynartice we combined LIDAR data with magnetometer and resistivity measurements and result of archaeological excavation. Fortunately for successful combination of geophysical and remote sensing results, their conditions and factors for efficient use in archaeology are not the same. On the other hand, the quality and state of many prehistoric, early medieval, medieval and also modern archaeological sites is rapidly changing over time and both groups of techniques represent important support for their comprehensive and precise documentation and protection.

  17. How to find non-dependent opiate users: a comparison of sampling methods in a field study of opium and heroin users.

    Science.gov (United States)

    Korf, Dirk J; van Ginkel, Patrick; Benschop, Annemieke

    2010-05-01

    The first aim is to better understand the potentials and limitations of different sampling methods for reaching a specific, rarely studied population of drug users and for persuading them to take part in a multidisciplinary study. The second is to determine the extent to which these different methods reach similar or dissimilar segments of the non-dependent opiate-using population. Using ethnographic fieldwork (EFW) and targeted canvassing (TARC; small newspaper advertisements and website announcements), supplemented by snowball referrals, we recruited and interviewed 127 non-dependent opiate users (lifetime prevalence of use 5-100 times; 86.6% had used heroin and 56.7% opium). Average age was 39.0; 66.1% were male and 33.9% female. In addition to opiates, many respondents had wide experience with other illicit drugs. The majority had non-conventional lifestyles. Both EFW and TARC yielded only limited numbers of snowball referrals. EFW requires specific skills, is labour-intensive, thus expensive, but allows unsuitable candidates to be excluded faster. Respondents recruited through EFW were significantly more likely to have experience with opium and various drugs other than opiates. TARC resulted in larger percentages of women and respondents with conventional lifestyles. TARC is less labour-intensive but requires more time for screening candidates; its cost-effectiveness depends on the price of advertising for the recruitment. Different methods reach different segments of the population of non-dependent opiate users. It is useful to employ a multi-method approach to reduce selectivity. Copyright 2009 Elsevier B.V. All rights reserved.

  18. Comparison of DNA Quantification Methods for Next Generation Sequencing.

    Science.gov (United States)

    Robin, Jérôme D; Ludlow, Andrew T; LaRanger, Ryan; Wright, Woodring E; Shay, Jerry W

    2016-04-06

    Next Generation Sequencing (NGS) is a powerful tool that depends on loading a precise amount of DNA onto a flowcell. NGS strategies have expanded our ability to investigate genomic phenomena by referencing mutations in cancer and diseases through large-scale genotyping, developing methods to map rare chromatin interactions (4C; 5C and Hi-C) and identifying chromatin features associated with regulatory elements (ChIP-seq, Bis-Seq, ChiA-PET). While many methods are available for DNA library quantification, there is no unambiguous gold standard. Most techniques use PCR to amplify DNA libraries to obtain sufficient quantities for optical density measurement. However, increased PCR cycles can distort the library's heterogeneity and prevent the detection of rare variants. In this analysis, we compared new digital PCR technologies (droplet digital PCR; ddPCR, ddPCR-Tail) with standard methods for the titration of NGS libraries. DdPCR-Tail is comparable to qPCR and fluorometry (QuBit) and allows sensitive quantification by analysis of barcode repartition after sequencing of multiplexed samples. This study provides a direct comparison between quantification methods throughout a complete sequencing experiment and provides the impetus to use ddPCR-based quantification for improvement of NGS quality.

  19. Evaluation and Comparison of Extremal Hypothesis-Based Regime Methods

    Directory of Open Access Journals (Sweden)

    Ishwar Joshi

    2018-03-01

    Full Text Available Regime channels are important for stable canal design and to determine river response to environmental changes, e.g., due to the construction of a dam, land use change, and climate shifts. A plethora of methods is available describing the hydraulic geometry of alluvial rivers in the regime. However, comparison of these methods using the same set of data seems lacking. In this study, we evaluate and compare four different extremal hypothesis-based regime methods, namely minimization of Froude number (MFN, maximum entropy and minimum energy dissipation rate (ME and MEDR, maximum flow efficiency (MFE, and Millar’s method, by dividing regime channel data into sand and gravel beds. The results show that for sand bed channels MFN gives a very high accuracy of prediction for regime channel width and depth. For gravel bed channels we find that MFN and ‘ME and MEDR’ give a very high accuracy of prediction for width and depth. Therefore the notion that extremal hypotheses which do not contain bank stability criteria are inappropriate for use is shown false as both MFN and ‘ME and MEDR’ lack bank stability criteria. Also, we find that bank vegetation has significant influence in the prediction of hydraulic geometry by MFN and ‘ME and MEDR’.

  20. Comparison of three instrumental methods for the objective evaluation of radiotherapy induced erythema in breast cancer patients and a study of the effect of skin lotions

    Energy Technology Data Exchange (ETDEWEB)

    Nystroem, Josefina; Lindholm-Sethson, Britta [Dept. of Chemistry, Umeaa Univ ., Umeaa (Sweden); Centre for Biomedical Engineering and Physics, Umeaa Univ., Umeaa (Sweden); Geladi, Paul [Unit of Biomass Technology and Chemistry, SLU Roebaecksdal en, Umeaa (Sweden); Svensk, Ann-Christine; Larson, Johan; Franzen, Lars [Dept. of Oncology, N orthern Univ. Hospital, Umeaa (Sweden)

    2007-10-15

    A non-blinded three armed study of the effect of Aloe vera, Essex and no lotion on erythema was performed. The erythema is an effect of radiotherapy treatment in breast cancer patients. The study required testing of objective methods for measuring the erythema. The chosen experimental methods were Near Infrared Spectroscopy, Laser Doppler Imaging and Digital Colour Photography. The experimental setup was made in such a way that in parallel with testing the effect of the lotions there was also a test of the sensitivity of the instruments. Fifty women were selected consecutively to participate in the study. They were all subjected to treatment with high-energy electrons (9-20 MeV) after mastectomy, 2 Gy/day to a total dose of 50 Gy. Measurements were performed before the start of radiotherapy and thereafter once a week during the course of treatment. Aloe vera and Essex lotion were applied twice every radiation day in selected sites. The increase in skin redness could be monitored with all techniques with a detection limit of 8 Gy for Digital Colour Photography and Near Infrared Spectroscopy and 18 Gy for Laser Doppler Imaging. In clinical practice our recommendation is to use Digital Colour Photography. No significant median differences were observed between the pairs no lotion-Essex, no lotion-Aloe vera and Essex-Aloe vera for any of the techniques tested.

  1. Comparison of three instrumental methods for the objective evaluation of radiotherapy induced erythema in breast cancer patients and a study of the effect of skin lotions

    International Nuclear Information System (INIS)

    Nystroem, Josefina; Lindholm-Sethson, Britta; Geladi, Paul; Svensk, Ann-Christine; Larson, Johan; Franzen, Lars

    2007-01-01

    A non-blinded three armed study of the effect of Aloe vera, Essex and no lotion on erythema was performed. The erythema is an effect of radiotherapy treatment in breast cancer patients. The study required testing of objective methods for measuring the erythema. The chosen experimental methods were Near Infrared Spectroscopy, Laser Doppler Imaging and Digital Colour Photography. The experimental setup was made in such a way that in parallel with testing the effect of the lotions there was also a test of the sensitivity of the instruments. Fifty women were selected consecutively to participate in the study. They were all subjected to treatment with high-energy electrons (9-20 MeV) after mastectomy, 2 Gy/day to a total dose of 50 Gy. Measurements were performed before the start of radiotherapy and thereafter once a week during the course of treatment. Aloe vera and Essex lotion were applied twice every radiation day in selected sites. The increase in skin redness could be monitored with all techniques with a detection limit of 8 Gy for Digital Colour Photography and Near Infrared Spectroscopy and 18 Gy for Laser Doppler Imaging. In clinical practice our recommendation is to use Digital Colour Photography. No significant median differences were observed between the pairs no lotion-Essex, no lotion-Aloe vera and Essex-Aloe vera for any of the techniques tested

  2. A Comparison of Multiple Methods for Estimating Parasitemia of Hemogregarine Hemoparasites (Apicomplexa: Adeleorina) and Its Application for Studying Infection in Natural Populations

    Science.gov (United States)

    Maia, João P.; Harris, D. James; Carranza, Salvador; Gómez-Díaz, Elena

    2014-01-01

    Identifying factors influencing infection patterns among hosts is critical for our understanding of the evolution and impact of parasitism in natural populations. However, the correct estimation of infection parameters depends on the performance of detection and quantification methods. In this study, we designed a quantitative PCR (qPCR) assay targeting the 18 S rRNA gene to estimate prevalence and intensity of Hepatozoon infection and compared its performance with microscopy and PCR. Using qPCR, we also compared various protocols that differ in the biological source and the extraction methods. Our results show that the qPCR approach on DNA extracted from blood samples, regardless of the extraction protocol, provided the most sensitive estimates of Hepatozoon infection parameters; while allowed us to differentiate between mixed infections of Adeleorinid (Hepatozoon) and Eimeriorinid (Schellackia and Lankesterella), based on the analysis of melting curves. We also show that tissue and saline methods can be used as low-cost alternatives in parasitological studies. The next step was to test our qPCR assay in a biological context, and for this purpose we investigated infection patterns between two sympatric lacertid species, which are naturally infected with apicomplexan hemoparasites, such as the genera Schellackia (Eimeriorina) and Hepatozoon (Adeleorina). From a biological standpoint, we found a positive correlation between Hepatozoon intensity of infection and host body size within each host species, being significantly higher in males, and higher in the smaller sized host species. These variations can be associated with a number of host intrinsic factors, like hormonal and immunological traits, that require further investigation. Our findings are relevant as they pinpoint the importance of accounting for methodological issues to better estimate infection in parasitological studies, and illustrate how between-host factors can influence parasite distributions in

  3. A comparison of multiple methods for estimating parasitemia of hemogregarine hemoparasites (apicomplexa: adeleorina and its application for studying infection in natural populations.

    Directory of Open Access Journals (Sweden)

    João P Maia

    Full Text Available Identifying factors influencing infection patterns among hosts is critical for our understanding of the evolution and impact of parasitism in natural populations. However, the correct estimation of infection parameters depends on the performance of detection and quantification methods. In this study, we designed a quantitative PCR (qPCR assay targeting the 18 S rRNA gene to estimate prevalence and intensity of Hepatozoon infection and compared its performance with microscopy and PCR. Using qPCR, we also compared various protocols that differ in the biological source and the extraction methods. Our results show that the qPCR approach on DNA extracted from blood samples, regardless of the extraction protocol, provided the most sensitive estimates of Hepatozoon infection parameters; while allowed us to differentiate between mixed infections of Adeleorinid (Hepatozoon and Eimeriorinid (Schellackia and Lankesterella, based on the analysis of melting curves. We also show that tissue and saline methods can be used as low-cost alternatives in parasitological studies. The next step was to test our qPCR assay in a biological context, and for this purpose we investigated infection patterns between two sympatric lacertid species, which are naturally infected with apicomplexan hemoparasites, such as the genera Schellackia (Eimeriorina and Hepatozoon (Adeleorina. From a biological standpoint, we found a positive correlation between Hepatozoon intensity of infection and host body size within each host species, being significantly higher in males, and higher in the smaller sized host species. These variations can be associated with a number of host intrinsic factors, like hormonal and immunological traits, that require further investigation. Our findings are relevant as they pinpoint the importance of accounting for methodological issues to better estimate infection in parasitological studies, and illustrate how between-host factors can influence parasite

  4. A comparison of multiple methods for estimating parasitemia of hemogregarine hemoparasites (apicomplexa: adeleorina) and its application for studying infection in natural populations.

    Science.gov (United States)

    Maia, João P; Harris, D James; Carranza, Salvador; Gómez-Díaz, Elena

    2014-01-01

    Identifying factors influencing infection patterns among hosts is critical for our understanding of the evolution and impact of parasitism in natural populations. However, the correct estimation of infection parameters depends on the performance of detection and quantification methods. In this study, we designed a quantitative PCR (qPCR) assay targeting the 18 S rRNA gene to estimate prevalence and intensity of Hepatozoon infection and compared its performance with microscopy and PCR. Using qPCR, we also compared various protocols that differ in the biological source and the extraction methods. Our results show that the qPCR approach on DNA extracted from blood samples, regardless of the extraction protocol, provided the most sensitive estimates of Hepatozoon infection parameters; while allowed us to differentiate between mixed infections of Adeleorinid (Hepatozoon) and Eimeriorinid (Schellackia and Lankesterella), based on the analysis of melting curves. We also show that tissue and saline methods can be used as low-cost alternatives in parasitological studies. The next step was to test our qPCR assay in a biological context, and for this purpose we investigated infection patterns between two sympatric lacertid species, which are naturally infected with apicomplexan hemoparasites, such as the genera Schellackia (Eimeriorina) and Hepatozoon (Adeleorina). From a biological standpoint, we found a positive correlation between Hepatozoon intensity of infection and host body size within each host species, being significantly higher in males, and higher in the smaller sized host species. These variations can be associated with a number of host intrinsic factors, like hormonal and immunological traits, that require further investigation. Our findings are relevant as they pinpoint the importance of accounting for methodological issues to better estimate infection in parasitological studies, and illustrate how between-host factors can influence parasite distributions in

  5. A Comparison of Moments-Based Logo Recognition Methods

    Directory of Open Access Journals (Sweden)

    Zili Zhang

    2014-01-01

    Full Text Available Logo recognition is an important issue in document image, advertisement, and intelligent transportation. Although there are many approaches to study logos in these fields, logo recognition is an essential subprocess. Among the methods of logo recognition, the descriptor is very vital. The results of moments as powerful descriptors were not discussed before in terms of logo recognition. So it is unclear which moments are more appropriate to recognize which kind of logos. In this paper we find out the relations between logos with different transforms and moments, which moments are fit for logos with different transforms. The open datasets are employed from the University of Maryland. The comparisons based on moments are carried out from the aspects of logos with noise, and rotation, scaling, rotation and scaling.

  6. Comparison of calculational methods for liquid metal reactor shields

    International Nuclear Information System (INIS)

    Carter, L.L.; Moore, F.S.; Morford, R.J.; Mann, F.M.

    1985-09-01

    A one-dimensional comparison is made between Monte Carlo (MCNP), discrete ordinances (ANISN), and diffusion theory (MlDX) calculations of neutron flux and radiation damage from the core of the Fast Flux Test Facility (FFTF) out to the reactor vessel. Diffusion theory was found to be reasonably accurate for the calculation of both total flux and radiation damage. However, for large distances from the core, the calculated flux at very high energies is low by an order of magnitude or more when the diffusion theory is used. Particular emphasis was placed in this study on the generation of multitable cross sections for use in discrete ordinates codes that are self-shielded, consistent with the self-shielding employed in the generation of cross sections for use with diffusion theory. The Monte Carlo calculation, with a pointwise representation of the cross sections, was used as the benchmark for determining the limitations of the other two calculational methods. 12 refs., 33 figs

  7. Comparison of optical methods for surface roughness characterization

    International Nuclear Information System (INIS)

    Feidenhans’l, Nikolaj A; Hansen, Poul-Erik; Madsen, Morten H; Petersen, Jan C; Pilný, Lukáš; Bissacco, Giuliano; Taboryski, Rafael

    2015-01-01

    We report a study of the correlation between three optical methods for characterizing surface roughness: a laboratory scatterometer measuring the bi-directional reflection distribution function (BRDF instrument), a simple commercial scatterometer (rBRDF instrument), and a confocal optical profiler. For each instrument, the effective range of spatial surface wavelengths is determined, and the common bandwidth used when comparing the evaluated roughness parameters. The compared roughness parameters are: the root-mean-square (RMS) profile deviation (Rq), the RMS profile slope (Rdq), and the variance of the scattering angle distribution (Aq). The twenty-two investigated samples were manufactured with several methods in order to obtain a suitable diversity of roughness patterns.Our study shows a one-to-one correlation of both the Rq and the Rdq roughness values when obtained with the BRDF and the confocal instruments, if the common bandwidth is applied. Likewise, a correlation is observed when determining the Aq value with the BRDF and the rBRDF instruments.Furthermore, we show that it is possible to determine the Rq value from the Aq value, by applying a simple transfer function derived from the instrument comparisons. The presented method is validated for surfaces with predominantly 1D roughness, i.e. consisting of parallel grooves of various periods, and a reflectance similar to stainless steel. The Rq values are predicted with an accuracy of 38% at the 95% confidence interval. (paper)

  8. Comparison of treatment effect estimates of non-vitamin K antagonist oral anticoagulants versus warfarin between observational studies using propensity score methods and randomized controlled trials

    International Nuclear Information System (INIS)

    Li, Guowei; Holbrook, Anne; Jin, Yanling; Zhang, Yonghong; Levine, Mitchell A. H.; Mbuagbaw, Lawrence; Witt, Daniel M.; Crowther, Mark; Connolly, Stuart; Chai-Adisaksopha, Chatree; Wan, Zhongxiao; Cheng, Ji; Thabane, Lehana

    2016-01-01

    Emerging observational studies using propensity score (PS) methods assessed real-world comparative effectiveness of non-vitamin K antagonist oral anticoagulants (NOACs) versus warfarin in patients with non-valvular atrial fibrillation (AF). We aimed to compare treatment effect estimates of NOACs between PS studies and randomized controlled trials (RCTs). Electronic databases and conference proceedings were searched systematically. Primary outcomes included stroke or systemic embolism (SE) and major bleeding. A random-effects meta-analysis was performed to synthesize the data by pooling the PS- and RCT-derived hazard ratios (HRs) separately. The ratio of HRs (RHR) from the ratio of PS-derived HRs relative to RCT-derived HRs was used to determine whether there was a difference between estimates from PS studies and RCTs. There were 10 PS studies and 5 RCTs included for analysis. No significant difference of treatment effect estimates between the PS studies and RCTs was observed: RHR 1.11, 95 % CI 0.98–1.23 for stroke or SE; RHR 1.07, 95 % CI 0.87–1.34 for major bleeding. A significant association between NOACs and risk of stroke or SE was observed: HR 0.88, 95 % CI 0.83–0.94 for the PS studies; HR 0.79, 95 % CI 0.72–0.87 for the RCTs. However, no relationship between NOACs and risk of major bleeding was found: HR 0.91, 95 % CI 0.79–1.05 for the PS studies; HR 0.85, 95 % CI 0.73–1.00 for the RCTs. In this study, treatment effect estimates of NOACs versus warfarin in patients with non-valvular AF from PS studies are found to be in agreement with those from RCTs.

  9. Comparison of mucosal lining fluid sampling methods and influenza-specific IgA detection assays for use in human studies of influenza immunity.

    Science.gov (United States)

    de Silva, Thushan I; Gould, Victoria; Mohammed, Nuredin I; Cope, Alethea; Meijer, Adam; Zutt, Ilse; Reimerink, Johan; Kampmann, Beate; Hoschler, Katja; Zambon, Maria; Tregoning, John S

    2017-10-01

    We need greater understanding of the mechanisms underlying protection against influenza virus to develop more effective vaccines. To do this, we need better, more reproducible methods of sampling the nasal mucosa. The aim of the current study was to compare levels of influenza virus A subtype-specific IgA collected using three different methods of nasal sampling. Samples were collected from healthy adult volunteers before and after LAIV immunization by nasal wash, flocked swabs and Synthetic Absorptive Matrix (SAM) strips. Influenza A virus subtype-specific IgA levels were measured by haemagglutinin binding ELISA or haemagglutinin binding microarray and the functional response was assessed by microneutralization. Nasosorption using SAM strips lead to the recovery of a more concentrated sample of material, with a significantly higher level of total and influenza H1-specific IgA. However, an equivalent percentage of specific IgA was observed with all sampling methods when normalized to the total IgA. Responses measured using a recently developed antibody microarray platform, which allows evaluation of binding to multiple influenza strains simultaneously with small sample volumes, were compared to ELISA. There was a good correlation between ELISA and microarray values. Material recovered from SAM strips was weakly neutralizing when used in an in vitro assay, with a modest correlation between the level of IgA measured by ELISA and neutralization, but a greater correlation between microarray-measured IgA and neutralizing activity. In conclusion we have tested three different methods of nasal sampling and show that flocked swabs and novel SAM strips are appropriate alternatives to traditional nasal washes for assessment of mucosal influenza humoral immunity. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. The Comparison of Learning Radiographic Extraoral Anatomic Landmarks through Lecture and blended method(Computer-Assisted teaching and Lecture:An interventional Study

    Directory of Open Access Journals (Sweden)

    T ahmine Razi

    2013-05-01

    Full Text Available Introduction: One of the main problems in learning extraoral radiographic anatomic indexes is the long interval between presentation of radiology and human anatomy courses, resulting in forgetting anatomic regions. Therefore, radiographic indexes are formed as complete abstract and transient images in students’ minds; as a result, their learning and retention decrease. The aim of this study was to compare lecture with combination of computer-assisted learning and lecture of extra-oral radiographic landmarks among dental students. Methods: This interventional study was carried out in 2009 on 51 dental students of Tabriz University of Medical Sciences. Students were randomly allocated into two groups. The first group was taught through a teaching method which involved lectures in the classroom. In the second group, a CD was given to the students. The teaching was accomplished through presentation using skull. Six months after finishing the teaching, both groups took a similar test for evaluation of long term learning. The data was analyzed by SPSS 16 using U Mann-Whitney test. Results: There was no significant differences in the mean scores between the two groups in the first exam after teaching (P=0.13, yet it was significant in the second exam (regarding retention (P=0.006, and average of non-traditional teaching method group (20.89±10.23 was higher than that of lecture group (13.48±6.39. Conclusion: Based on the results, non-traditional technique of teaching was not more effective than the lecture in short-term learning but in longterm learning, non-traditional technique was more effective than the lecture.

  11. Comparison of address-based sampling and random-digit dialing methods for recruiting young men as controls in a case-control study of testicular cancer susceptibility.

    Science.gov (United States)

    Clagett, Bartholt; Nathanson, Katherine L; Ciosek, Stephanie L; McDermoth, Monique; Vaughn, David J; Mitra, Nandita; Weiss, Andrew; Martonik, Rachel; Kanetsky, Peter A

    2013-12-01

    Random-digit dialing (RDD) using landline telephone numbers is the historical gold standard for control recruitment in population-based epidemiologic research. However, increasing cell-phone usage and diminishing response rates suggest that the effectiveness of RDD in recruiting a random sample of the general population, particularly for younger target populations, is decreasing. In this study, we compared landline RDD with alternative methods of control recruitment, including RDD using cell-phone numbers and address-based sampling (ABS), to recruit primarily white men aged 18-55 years into a study of testicular cancer susceptibility conducted in the Philadelphia, Pennsylvania, metropolitan area between 2009 and 2012. With few exceptions, eligible and enrolled controls recruited by means of RDD and ABS were similar with regard to characteristics for which data were collected on the screening survey. While we find ABS to be a comparably effective method of recruiting young males compared with landline RDD, we acknowledge the potential impact that selection bias may have had on our results because of poor overall response rates, which ranged from 11.4% for landline RDD to 1.7% for ABS.

  12. INTER LABORATORY COMBAT HELMET BLUNT IMPACT TEST METHOD COMPARISON

    Science.gov (United States)

    2018-03-26

    data by Instrumentation for Impact  Test , SAE standard J211‐1 [4]. Although the entire curve is collected, the interest of this  project  team  solely...HELMET BLUNT IMPACT TEST METHOD COMPARISON by Tony J. Kayhart Charles A. Hewitt and Jonathan Cyganik March 2018 Final...INTER-LABORATORY COMBAT HELMET BLUNT IMPACT TEST METHOD COMPARISON 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR

  13. An empirical comparison of several recent epistatic interaction detection methods.

    Science.gov (United States)

    Wang, Yue; Liu, Guimei; Feng, Mengling; Wong, Limsoon

    2011-11-01

    Many new methods have recently been proposed for detecting epistatic interactions in GWAS data. There is, however, no in-depth independent comparison of these methods yet. Five recent methods-TEAM, BOOST, SNPHarvester, SNPRuler and Screen and Clean (SC)-are evaluated here in terms of power, type-1 error rate, scalability and completeness. In terms of power, TEAM performs best on data with main effect and BOOST performs best on data without main effect. In terms of type-1 error rate, TEAM and BOOST have higher type-1 error rates than SNPRuler and SNPHarvester. SC does not control type-1 error rate well. In terms of scalability, we tested the five methods using a dataset with 100 000 SNPs on a 64 bit Ubuntu system, with Intel (R) Xeon(R) CPU 2.66 GHz, 16 GB memory. TEAM takes ~36 days to finish and SNPRuler reports heap allocation problems. BOOST scales up to 100 000 SNPs and the cost is much lower than that of TEAM. SC and SNPHarvester are the most scalable. In terms of completeness, we study how frequently the pruning techniques employed by these methods incorrectly prune away the most significant epistatic interactions. We find that, on average, 20% of datasets without main effect and 60% of datasets with main effect are pruned incorrectly by BOOST, SNPRuler and SNPHarvester. The software for the five methods tested are available from the URLs below. TEAM: http://csbio.unc.edu/epistasis/download.php BOOST: http://ihome.ust.hk/~eeyang/papers.html. SNPHarvester: http://bioinformatics.ust.hk/SNPHarvester.html. SNPRuler: http://bioinformatics.ust.hk/SNPRuler.zip. Screen and Clean: http://wpicr.wpic.pitt.edu/WPICCompGen/. wangyue@nus.edu.sg.

  14. Monitoring uterine activity during labor: a comparison of three methods

    Science.gov (United States)

    EULIANO, Tammy Y.; NGUYEN, Minh Tam; DARMANJIAN, Shalom; MCGORRAY, Susan P.; EULIANO, Neil; ONKALA, Allison; GREGG, Anthony R.

    2012-01-01

    Objective Tocodynamometry (Toco—strain gauge technology) provides contraction frequency and approximate duration of labor contractions, but suffers frequent signal dropout necessitating re-positioning by a nurse, and may fail in obese patients. The alternative invasive intrauterine pressure catheter (IUPC) is more reliable and adds contraction pressure information, but requires ruptured membranes and introduces small risks of infection and abruption. Electrohysterography (EHG) reports the electrical activity of the uterus through electrodes placed on the maternal abdomen. This study compared all three methods of contraction detection simultaneously in laboring women. Study Design Upon consent, laboring women were monitored simultaneously with Toco, EHG, and IUPC. Contraction curves were generated in real-time for the EHG and all three curves were stored electronically. A contraction detection algorithm was used to compare frequency and timing between methods. Seventy-three subjects were enrolled in the study; 14 were excluded due to hardware failure of one or more of the devices (12) or inadequate data collection duration(2). Results In comparison with the gold-standard IUPC, EHG performed significantly better than Toco with regard to Contractions Consistency Index (CCI). The mean CCI for EHG was 0.88 ± 0.17 compared to 0.69 ± 0.27 for Toco (pToco, EHG was not significantly affected by obesity. Conclusion Toco does not correlate well with the gold-standard IUPC and fails more frequently in obese patients. EHG provides a reliable non-invasive alternative regardless of body habitus. PMID:23122926

  15. Comparison of sampling methods for the assessment of indoor microbial exposure

    DEFF Research Database (Denmark)

    Frankel, M; Timm, Michael; Hansen, E W

    2012-01-01

    revealed. This study thus facilitates comparison between methods and may therefore be used as a frame of reference when studying the literature or when conducting further studies on indoor microbial exposure. Results also imply that the relatively simple EDC method for the collection of settled dust may...

  16. A Comparison of Fully Automated Methods of Data Analysis and Computer Assisted Heuristic Methods in an Electrode Kinetic Study of the Pathologically Variable [Fe(CN) 6 ] 3–/4– Process by AC Voltammetry

    KAUST Repository

    Morris, Graham P.

    2013-12-17

    Fully automated and computer assisted heuristic data analysis approaches have been applied to a series of AC voltammetric experiments undertaken on the [Fe(CN)6]3-/4- process at a glassy carbon electrode in 3 M KCl aqueous electrolyte. The recovered parameters in all forms of data analysis encompass E0 (reversible potential), k0 (heterogeneous charge transfer rate constant at E0), α (charge transfer coefficient), Ru (uncompensated resistance), and Cdl (double layer capacitance). The automated method of analysis employed time domain optimization and Bayesian statistics. This and all other methods assumed the Butler-Volmer model applies for electron transfer kinetics, planar diffusion for mass transport, Ohm\\'s Law for Ru, and a potential-independent Cdl model. Heuristic approaches utilize combinations of Fourier Transform filtering, sensitivity analysis, and simplex-based forms of optimization applied to resolved AC harmonics and rely on experimenter experience to assist in experiment-theory comparisons. Remarkable consistency of parameter evaluation was achieved, although the fully automated time domain method provided consistently higher α values than those based on frequency domain data analysis. The origin of this difference is that the implemented fully automated method requires a perfect model for the double layer capacitance. In contrast, the importance of imperfections in the double layer model is minimized when analysis is performed in the frequency domain. Substantial variation in k0 values was found by analysis of the 10 data sets for this highly surface-sensitive pathologically variable [Fe(CN) 6]3-/4- process, but remarkably, all fit the quasi-reversible model satisfactorily. © 2013 American Chemical Society.

  17. A comparison of two analytical evaluation methods for educational computer games for young children

    NARCIS (Netherlands)

    Bekker, M.M.; Baauw, E.; Barendregt, W.

    2008-01-01

    In this paper we describe a comparison of two analytical methods for educational computer games for young children. The methods compared in the study are the Structured Expert Evaluation Method (SEEM) and the Combined Heuristic Evaluation (HE) (based on a combination of Nielsen’s HE and the

  18. Monitoring uterine activity during labor: a comparison of 3 methods.

    Science.gov (United States)

    Euliano, Tammy Y; Nguyen, Minh Tam; Darmanjian, Shalom; McGorray, Susan P; Euliano, Neil; Onkala, Allison; Gregg, Anthony R

    2013-01-01

    Tocodynamometry (Toco; strain gauge technology) provides contraction frequency and approximate duration of labor contractions but suffers frequent signal dropout, necessitating repositioning by a nurse, and may fail in obese patients. The alternative invasive intrauterine pressure catheter (IUPC) is more reliable and adds contraction pressure information but requires ruptured membranes and introduces small risks of infection and abruption. Electrohysterography (EHG) reports the electrical activity of the uterus through electrodes placed on the maternal abdomen. This study compared all 3 methods of contraction detection simultaneously in laboring women. Upon consent, laboring women were monitored simultaneously with Toco, EHG, and IUPC. Contraction curves were generated in real-time for the EHG, and all 3 curves were stored electronically. A contraction detection algorithm was used to compare frequency and timing between methods. Seventy-three subjects were enrolled in the study; 14 were excluded due to hardware failure of 1 or more of the devices (n = 12) or inadequate data collection duration (n = 2). In comparison with the gold-standard IUPC, EHG performed significantly better than Toco with regard to the Contractions Consistency Index (CCI). The mean CCI for EHG was 0.88 ± 0.17 compared with 0.69 ± 0.27 for Toco (P Toco, EHG was not significantly affected by obesity. Toco does not correlate well with the gold-standard IUPC and fails more frequently in obese patients. EHG provides a reliable noninvasive alternative, regardless of body habitus. Copyright © 2013 Mosby, Inc. All rights reserved.

  19. A comparison of methods to determine tannin acyl hydrolase activity

    Directory of Open Access Journals (Sweden)

    Cristóbal Aguilar

    1999-01-01

    Full Text Available Six methods to determine the activity of tannase produced by Aspergillus niger Aa-20 on polyurethane foam by solid state fermentation, which included two titrimetric techniques, three spectrophotometric methods and one HPLC assay were tested and compared. All methods assayed enabled the measurement of extracellular tannase activity. However, only five were useful to evaluate intracellular tannase activity. Studies on the effect of pH on tannase extraction demonstrated that tannase activity was considerably under-estimated when its extraction was carried out at pH values below 5.5 and above 6.0. Results showed that the HPLC technique and the modified Bajpai and Patil methods presented several advantages in comparison to the other methods tested.Seis métodos para determinar a atividade de tannase produzida por Aspergillus niger O Aa-20 em espuma de polyuretano por fermentação em estado sólido foram estudados. Duas técnicas titulométricas , três métodos spectrofotométricos e um método por HPLC foram testados e comparados. Todos os métodos testados permitiram determinar a atividade da tannase produzida extracelularmente. Entretanto, somente cinco se mostraram úteis para avaliar a atividade da tannase produzida intracelularmente. Os estudos do efeito do pH na extração de tannase demonstraram que a atividade de tannase era consideravelmente subestimada quando sua extração foi executada em valores de pH inferiores a 5.5 e superior a pH 6.0. Os resultados demostraram que a técnica de HPLC o método Bajpai and Patil modificado apresentam várias vantagens em comparação aos outros métodos testados.

  20. A comparison of non-invasive versus invasive methods of ...

    African Journals Online (AJOL)

    Puneet Khanna

    for Hb estimation from the laboratory [total haemoglobin mass (tHb)] and arterial blood gas (ABG) machine (aHb), using ... A comparison of non-invasive versus invasive methods of haemoglobin estimation in patients undergoing intracranial surgery. 161 .... making decisions for blood transfusions based on these results.

  1. Removal of phenol from water : a comparison of energization methods

    NARCIS (Netherlands)

    Grabowski, L.R.; Veldhuizen, van E.M.; Rutgers, W.R.

    2005-01-01

    Direct electrical energization methods for removal of persistent substances from water are under investigation in the framework of the ytriD-project. The emphasis of the first stage of the project is the energy efficiency. A comparison is made between a batch reactor with a thin layer of water and

  2. Comparison of radioimmunology and serology methods for LH determination

    International Nuclear Information System (INIS)

    Szymanski, W.; Jakowicki, J.

    1976-01-01

    A comparison is presented of LH determinations by immunoassay and radioimmunoassay using the 125 I-labelled HCG double antibody system. The results obtained by both methods are well comparable and in normal and elevated LH levels the serological determinations may be used for estimating concentration levels found by RIA. (L.O.)

  3. Proper comparison among methods using a confusion matrix

    CSIR Research Space (South Africa)

    Salmon

    2015-07-01

    Full Text Available -1 IGARSS 2015, Milan, Italy, 26-31 July 2015 Proper comparison among methods using a confusion matrix 1,2 B.P. Salmon, 2,3 W. Kleynhans, 2,3 C.P. Schwegmann and 1J.C. Olivier 1School of Engineering and ICT, University of Tasmania, Australia 2...

  4. The electronic states of 1,2,3-triazole studied by vacuum ultraviolet photoabsorption and ultraviolet photoelectron spectroscopy, and a comparison with ab initio configuration interaction methods

    DEFF Research Database (Denmark)

    Palmer, Michael H.; Hoffmann, Søren Vrønning; Jones, Nykola C.

    2011-01-01

    The Rydberg states in the vacuum ultraviolet photoabsorption spectrum of 1,2,3-triazole have been measured and analyzed with the aid of comparison to the UV valence photoelectron ionizations and the results of ab initio configuration interaction (CI) calculations. Calculated electronic ionization...... and excitation energies for singlet, triplet valence, and Rydberg states were obtained using multireference multiroot CI procedures with an aug-cc-pVTZ [5s3p3d1f] basis set and a set of Rydberg [4s3p3d3f] functions. Adiabatic excitation energies obtained for several electronic states using coupled...... are the excitations consistent with an f-series....

  5. Comparison the diagnostic value of serological and molecular methods for screening and detecting Chlamydia trachomatis in semen of infertile men: A cross-sectional study

    Directory of Open Access Journals (Sweden)

    Amin Khoshakhlagh

    2017-12-01

    Full Text Available Background: Chlamydia trachomatis (CT with damaging effects on sperm quality parameters can often cause infertility in men. Objective: The main objective of this study was to determine the diagnostic value of polymerase chain reaction (PCR and enzyme linked immuno sorbent assay (ELISA for screening and detecting CT in semen samples of infertile men. Materials and Methods: In this cross-sectional study, 465 men referring to the clinical laboratory of Royan Institute were chosen for primary screening and detection of the presence of CT. 93 samples were normozoospermia with normal sperm parameters i.e. sperm number, motility and morphology (Asymptomatic and 372 had abnormal sperm parameters (Symptomatic in semen analysis. ELISA test was performed as the screening test. Samples with optical density (OD >0.200 were selected as the case and asymptomatic samples with OD 0.400 as the ELISA positive, the diagnostic value of CT-ELISA positive in symptomatic and asymptomatic infertile patients were 0.019 (7 of 372 and 0.021 (2 of 93, respectively. There was no relationship between the presence of CT infection and different sperm abnormalities. Conclusion: The anti-CT IgA ELISA test may be introduced as an appropriate tool for screening purpose in the seminal plasma to select suspicious samples for PCR confirmatory tests.

  6. Comparison of different methods for the solution of sets of linear equations

    International Nuclear Information System (INIS)

    Bilfinger, T.; Schmidt, F.

    1978-06-01

    The application of the conjugate-gradient methods as novel general iterative methods for the solution of sets of linear equations with symmetrical systems matrices led to this paper, where a comparison of these methods with the conventional differently accelerated Gauss-Seidel iteration was carried out. In additon, the direct Cholesky method was also included in the comparison. The studies referred mainly to memory requirement, computing time, speed of convergence, and accuracy of different conditions of the systems matrices, by which also the sensibility of the methods with respect to the influence of truncation errors may be recognized. (orig.) 891 RW [de

  7. Comparação entre métodos para o estudo da estabilidade de agregados em solos Comparison of methods for aggregate stability studies in soils

    Directory of Open Access Journals (Sweden)

    MARCOS AURÉLIO CAROLINO DE SÁ

    2000-09-01

    Full Text Available A estabilidade de agregados constitui-se em importante parâmetro na avaliação do efeito de manejo na agregação de solos. Entretanto, os resultados obtidos pelos diferentes métodos são, às vezes, contrastantes, e alguns desses métodos não permitem a definição do nível de energia envolvido na análise. Objetivou-se, com este estudo, comparar diferentes métodos para determinação da estabilidade de agregados em solos. Agregados de horizontes A e B de Latossolo Roxo (LR e Terra Roxa Estruturada (TR foram submetidos a peneiramento úmido, três testes de impacto de gotas, e sonificação a oito níveis de energia ultra-sônica; o primeiro foi comparado aos últimos, que permitem a quantificação da energia aplicada. De modo geral, o LR apresentou agregados mais estáveis do que a TR; a resistência dos agregados a altos níveis de energia ultra-sônica foi relacionada a teores de matéria orgânica, óxidos de ferro e gibbsita. Os resultados de diâmetro médio ponderado e porcentagem de agregados maiores que 2 mm foram semelhantes nos horizontes A de ambos os solos. O impacto de gotas causou maior desagregação no material de horizonte B do LR, enquanto o material de horizonte B da TR foi mais afetado pelo peneiramento úmido. O nível de 15,88 J mL-1 se apresentou, na sonificação, como mais sensível para detectar diferenças entre solos estudados.Aggregate stability is an important parameter to express the effect of management on soil aggregation. However, the results from different methods are sometimes contrasting. Some of them do not express the aggregate stability in terms of level of energy needed for aggregate disruption. The objective of this study was to compare methods for determining soil aggregate stability. Aggregates of Dusky-Red Latossol (DRL and a Structured Dusky-Red Earth (SDR were submitted to wet sieving (WS, three water drop tests, and eight levels of sonication energy. Correlation was obtained between the

  8. A comparison of three time-domain anomaly detection methods

    Energy Technology Data Exchange (ETDEWEB)

    Schoonewelle, H.; Hagen, T.H.J.J. van der; Hoogenboom, J.E. [Delft University of Technology (Netherlands). Interfaculty Reactor Institute

    1996-01-01

    Three anomaly detection methods based on a comparison of signal values with predictions from an autoregressive model are presented. These methods are: the extremes method, the {chi}{sup 2} method and the sequential probability ratio test. The methods are used to detect a change of the standard deviation of the residual noise obtained from applying an autoregressive model. They are fast and can be used in on-line applications. For each method some important anomaly detection parameters are determined by calculation or simulation. These parameters are: the false alarm rate, the average time to alarm and - being of minor importance -the alarm failure rate. Each method is optimized with respect to the average time to alarm for a given value of the false alarm rate. The methods are compared with each other, resulting in the sequential probability ratio test being clearly superior. (author).

  9. A comparison of three time-domain anomaly detection methods

    International Nuclear Information System (INIS)

    Schoonewelle, H.; Hagen, T.H.J.J. van der; Hoogenboom, J.E.

    1996-01-01

    Three anomaly detection methods based on a comparison of signal values with predictions from an autoregressive model are presented. These methods are: the extremes method, the χ 2 method and the sequential probability ratio test. The methods are used to detect a change of the standard deviation of the residual noise obtained from applying an autoregressive model. They are fast and can be used in on-line applications. For each method some important anomaly detection parameters are determined by calculation or simulation. These parameters are: the false alarm rate, the average time to alarm and - being of minor importance -the alarm failure rate. Each method is optimized with respect to the average time to alarm for a given value of the false alarm rate. The methods are compared with each other, resulting in the sequential probability ratio test being clearly superior. (author)

  10. Comparison of six different methods of cleaning and preparing occlusal fissure surface before placement of pit and fissure sealant: An in vitro study

    Directory of Open Access Journals (Sweden)

    A Agrawal

    2012-01-01

    Full Text Available Aim & Objectives : The purpose of this in vitro study was to evaluate and compare the microleakage of pit and fissure sealants after using six different preparation techniques: (a brush, (b pumice slurry application, (c bur, (d air polishing, (e air abrasion, and (f longer etching time. Material & Method : The study was conducted on 60 caries-free first premolars extracted for orthodontic purpose. These teeth were randomly assigned to six groups of 10 teeth each. Teeth were prepared using one of six occlusal surface treatments prior to placement of Clinpro" 3M ESPE light-cured sealant. The teeth were thermocycled for 500 cycles and stored in 0.9% normal saline. Teeth were sealed apically and coated with nail varnish 1 mm from the margin and stained in 1% methylene blue for 24 hours. Each tooth was divided buccolingually parallel to the long axis of the tooth, yielding two sections per tooth for analysis. The surfaces were scored from 0 to 2 for the extent of microleakage. Statistical Analysis : Results obtained for microleakage were analyzed by using t-tests at sectional level and chi-square test and analysis of variance (ANOVA at the group level. Results : The results of round bur group were significantly superior when compared to all other groups. The application of air polishing and air abrasion showed better results than pumice slurry, bristle brush, and longer etching time. Round bur group was the most successful cleaning and preparing technique. Air polishing and air abrasion produced significantly less microleakage than traditional pumice slurry, bristle brush, and longer etching time.

  11. ACCELERATION RENDERING METHOD ON RAY TRACING WITH ANGLE COMPARISON AND DISTANCE COMPARISON

    Directory of Open Access Journals (Sweden)

    Liliana liliana

    2007-01-01

    Full Text Available In computer graphics applications, to produce realistic images, a method that is often used is ray tracing. Ray tracing does not only model local illumination but also global illumination. Local illumination count ambient, diffuse and specular effects only, but global illumination also count mirroring and transparency. Local illumination count effects from the lamp(s but global illumination count effects from other object(s too. Objects that are usually modeled are primitive objects and mesh objects. The advantage of mesh modeling is various, interesting and real-like shape. Mesh contains many primitive objects like triangle or square (rare. A problem in mesh object modeling is long rendering time. It is because every ray must be checked with a lot of triangle of the mesh. Added by ray from other objects checking, the number of ray that traced will increase. It causes the increasing of rendering time. To solve this problem, in this research, new methods are developed to make the rendering process of mesh object faster. The new methods are angle comparison and distance comparison. These methods are used to reduce the number of ray checking. The rays predicted will not intersect with the mesh, are not checked weather the ray intersects the mesh. With angle comparison, if using small angle to compare, the rendering process will be fast. This method has disadvantage, if the shape of each triangle is big, some triangles will be corrupted. If the angle to compare is bigger, mesh corruption can be avoided but the rendering time will be longer than without comparison. With distance comparison, the rendering time is less than without comparison, and no triangle will be corrupted.

  12. Comparison of detection methods and follow-up study on the tyrosine kinase inhibitors therapy in non-small cell lung cancer patients with ROS1 fusion rearrangement

    International Nuclear Information System (INIS)

    Wu, Jieyu; Lin, Yunen; He, Xinming; Yang, Haihong; He, Ping; Fu, Xinge; Li, Guangqiu; Gu, Xia

    2016-01-01

    The screening of ROS proto-oncogene 1, receptor tyrosine kinase(ROS1) fusion rearrangement might be potentially beneficial for an effective therapy against non-small cell lung cancer (NSCLC). However, the three main ROS1 rearrangement detection methods have limitations, and no routine protocol for the detection of ROS1 rearrangement in NSCLC is available. In this study, our aims were to compare immunohistochemistry (IHC), fluorescent in situ hybridization (FISH) and quantitative real-time polymerase chain reaction (qRT-PCR) in their ability to detect ROS1 rearrangement in NSCLC, and discuss the clinical characteristics and histopathology of the patients with ROS1 rearrangement. Moreover, the effects of tyrosine kinase inhibitors (TKIs) therapy on the patients with ROS1 rearrangement and advanced stage disease (III b–IV) were investigated. Patients with a previously diagnosed NSCLC were recruited in this study from November 2013 to October 2015. IHC was performed using the D4D6 monoclonal antibody (mAb) in an automatic IHC instrument, while FISH and qRT-PCR were carried out to confirm the IHC results. FISH and qRT-PCR positive cases underwent direct sequencing. After detection, patients with advanced ROS1 rearranged NSCLC had received TKI therapy. Two hundred and thirty-eight patients were included in this study. ROS1 rearrangement was detected in 10 patients. The concordant rate of FISH and qRT-PCR results was 100 %, while in the FISH and IHC results high congruence was present when IHC showed a diffusely (≥60 % tumor cells) 2–3+ cytoplasmic reactivity pattern. Patients harboring ROS1 rearrangement were mostly young (8/10), females (7/10) and non-smokers (7/10) with adenocarcinoma (10/10) and acinar pattern. Most of their tumor were in intermediate grade (6/8). Among these 10 patients, three of them in stage IV with ROS1 rearrangement gained benefits from ROS1 TKI therapy. IHC, FISH and qRT-PCR can reliably detect ROS1 rearrangement in NSCLC, while IHC can be

  13. Comparison of longitudinal excursion of a nerve-phantom model using quantitative ultrasound imaging and motion analysis system methods: A convergent validity study.

    Science.gov (United States)

    Paquette, Philippe; El Khamlichi, Youssef; Lamontagne, Martin; Higgins, Johanne; Gagnon, Dany H

    2017-08-01

    Quantitative ultrasound imaging is gaining popularity in research and clinical settings to measure the neuromechanical properties of the peripheral nerves such as their capability to glide in response to body segment movement. Increasing evidence suggests that impaired median nerve longitudinal excursion is associated with carpal tunnel syndrome. To date, psychometric properties of longitudinal nerve excursion measurements using quantitative ultrasound imaging have not been extensively investigated. This study investigates the convergent validity of the longitudinal nerve excursion by comparing measures obtained using quantitative ultrasound imaging with those determined with a motion analysis system. A 38-cm long rigid nerve-phantom model was used to assess the longitudinal excursion in a laboratory environment. The nerve-phantom model, immersed in a 20-cm deep container filled with a gelatin-based solution, was moved 20 times using a linear forward and backward motion. Three light-emitting diodes were used to record nerve-phantom excursion with a motion analysis system, while a 5-cm linear transducer allowed simultaneous recording via ultrasound imaging. Both measurement techniques yielded excellent association ( r  = 0.99) and agreement (mean absolute difference between methods = 0.85 mm; mean relative difference between methods = 7.48 %). Small discrepancies were largely found when larger excursions (i.e. > 10 mm) were performed, revealing slight underestimation of the excursion by the ultrasound imaging analysis software. Quantitative ultrasound imaging is an accurate method to assess the longitudinal excursion of an in vitro nerve-phantom model and appears relevant for future research protocols investigating the neuromechanical properties of the peripheral nerves.

  14. What Is Social Comparison and How Should We Study It?

    Science.gov (United States)

    Wood, Joanne V.

    1996-01-01

    Examines frequently used measures and procedures in social comparison research. The question of whether a method truly captures social comparison requires a clear understanding of what social comparison is; hence a definition of social comparison is proposed, multiple ancillary processes in social comparison are identified, and definitional…

  15. A Novel Mobile Phone Application for Pulse Pressure Variation Monitoring Based on Feature Extraction Technology: A Method Comparison Study in a Simulated Environment.

    Science.gov (United States)

    Desebbe, Olivier; Joosten, Alexandre; Suehiro, Koichi; Lahham, Sari; Essiet, Mfonobong; Rinehart, Joseph; Cannesson, Maxime

    2016-07-01

    Pulse pressure variation (PPV) can be used to assess fluid status in the operating room. This measurement, however, is time consuming when done manually and unreliable through visual assessment. Moreover, its continuous monitoring requires the use of expensive devices. Capstesia™ is a novel Android™/iOS™ application, which calculates PPV from a digital picture of the arterial pressure waveform obtained from any monitor. The application identifies the peaks and troughs of the arterial curve, determines maximum and minimum pulse pressures, and computes PPV. In this study, we compared the accuracy of PPV generated with the smartphone application Capstesia (PPVapp) against the reference method that is the manual determination of PPV (PPVman). The Capstesia application was loaded onto a Samsung Galaxy S4 phone. A physiologic simulator including PPV was used to display arterial waveforms on a computer screen. Data were obtained with different sweep speeds (6 and 12 mm/s) and randomly generated PPV values (from 2% to 24%), pulse pressure (30, 45, and 60 mm Hg), heart rates (60-80 bpm), and respiratory rates (10-15 breaths/min) on the simulator. Each metric was recorded 5 times at an arterial height scale X1 (PPV5appX1) and 5 times at an arterial height scale X3 (PPV5appX3). Reproducibility of PPVapp and PPVman was determined from the 5 pictures of the same hemodynamic profile. The effect of sweep speed, arterial waveform scale (X1 or X3), and number of images captured was assessed by a Bland-Altman analysis. The measurement error (ME) was calculated for each pair of data. A receiver operating characteristic curve analysis determined the ability of PPVapp to discriminate a PPVman > 13%. Four hundred eight pairs of PPVapp and PPVman were analyzed. The reproducibility of PPVapp and PPVman was 10% (interquartile range, 7%-14%) and 6% (interquartile range, 3%-10%), respectively, allowing a threshold ME of 12%. The overall mean bias for PPVappX1 was 1.1% within limits of

  16. Comparison studies of surface cleaning methods for PAN-based carbon fibers with acetone, supercritical acetone and subcritical alkali aqueous solutions

    International Nuclear Information System (INIS)

    Meng Linghui; Fan Dapeng; Huang Yudong; Jiang Zaixing; Zhang Chunhua

    2012-01-01

    Highlights: ► Cleaning with supercritical acetone is appropriate to wipe off the oxygenated contaminants. ► Cleaning with supercritical acetone causes smaller damage to bulk strength of carbon fibers. ► Cleaning with subcritical alkali aqueous solution can thoroughly remove silicious contaminants. - Abstract: Four kinds of polyacrylonitrile-based carbon fibers were cleaned by three methods and were characterized by X-ray photoelectron spectroscopy, monofilament tensile strength test and atomic force microscopy (AFM). Experimental results of these tests reveal that the method using supercritical acetone or subcritical potassium hydroxide aqueous solution act as the processing medium shows a better cleaning effect compared to the traditional method, Soxhlet extraction with acetone. The method using supercritical acetone is more appropriate to wipe off the oxygenated contaminants on carbon fibers’ surfaces and causes a relatively smaller damage to the bulk strength of each carbon fiber. As far as treating method using the subcritical alkali aqueous solution, it can thoroughly remove silicious contaminants on the surfaces of treated fibers.

  17. Evaluation and comparison of the processing methods of airborne gravimetry concerning the errors effects on downward continuation results: Case studies in Louisiana (USA) and the Tibetan Plateau (China)

    DEFF Research Database (Denmark)

    Zhao, Qilong; Strykowski, Gabriel; Li, Jiancheng

    2017-01-01

    and the most extreme area of the world for this type of survey is the Tibetan Plateau. Since there are no high-accuracy surface gravity data available for this area, the above error minimization method involving the external gravity data cannot be used. We propose a semi-parametric downward continuation method...... in combination with regularization to suppress the systematic error effect and the random error effect in the Tibetan Plateau; i.e., without the use of the external high-accuracy gravity data. We use a Louisiana airborne gravity dataset from the USA National Oceanic and Atmospheric Administration (NOAA......) to demonstrate that the new method works effectively. Furthermore, and for the Tibetan Plateau we show that the numerical experiment is also successfully conducted using the synthetic Earth Gravitational Model 2008 (EGM08)-derived gravity data contaminated with the synthetic errors. The estimated systematic...

  18. Comparison of vibrational conductivity and radiative energy transfer methods

    Science.gov (United States)

    Le Bot, A.

    2005-05-01

    This paper is concerned with the comparison of two methods well suited for the prediction of the wideband response of built-up structures subjected to high-frequency vibrational excitation. The first method is sometimes called the vibrational conductivity method and the second one is rather known as the radiosity method in the field of acoustics, or the radiative energy transfer method. Both are based on quite similar physical assumptions i.e. uncorrelated sources, mean response and high-frequency excitation. Both are based on analogies with some equations encountered in the field of heat transfer. However these models do not lead to similar results. This paper compares the two methods. Some numerical simulations on a pair of plates joined along one edge are provided to illustrate the discussion.

  19. A Simplified Version of the Fuzzy Decision Method and its Comparison with the Paraconsistent Decision Method

    Science.gov (United States)

    de Carvalho, Fábio Romeu; Abe, Jair Minoro

    2010-11-01

    Two recent non-classical logics have been used to make decision: fuzzy logic and paraconsistent annotated evidential logic Et. In this paper we present a simplified version of the fuzzy decision method and its comparison with the paraconsistent one. Paraconsistent annotated evidential logic Et, introduced by Da Costa, Vago and Subrahmanian (1991), is capable of handling uncertain and contradictory data without becoming trivial. It has been used in many applications such as information technology, robotics, artificial intelligence, production engineering, decision making etc. Intuitively, one Et logic formula is type p(a, b), in which a and b belong to [0, 1] (real interval) and represent respectively the degree of favorable evidence (or degree of belief) and the degree of contrary evidence (or degree of disbelief) found in p. The set of all pairs (a; b), called annotations, when plotted, form the Cartesian Unitary Square (CUS). This set, containing a similar order relation of real number, comprises a network, called lattice of the annotations. Fuzzy logic was introduced by Zadeh (1965). It tries to systematize the knowledge study, searching mainly to study the fuzzy knowledge (you don't know what it means) and distinguish it from the imprecise one (you know what it means, but you don't know its exact value). This logic is similar to paraconsistent annotated one, since it attributes a numeric value (only one, not two values) to each proposition (then we can say that it is an one-valued logic). This number translates the intensity (the degree) with which the preposition is true. Let's X a set and A, a subset of X, identified by the function f(x). For each element x∈X, you have y = f(x)∈[0, 1]. The number y is called degree of pertinence of x in A. Decision making theories based on these logics have shown to be powerful in many aspects regarding more traditional methods, like the one based on Statistics. In this paper we present a first study for a simplified

  20. Studying the method of linearization of exponential calibration curves

    International Nuclear Information System (INIS)

    Bunzh, Z.A.

    1989-01-01

    The results of study of the method for linearization of exponential calibration curves are given. The calibration technique and comparison of the proposed method with piecewise-linear approximation and power series expansion, are given

  1. Determination of telmisartan in human blood plasma: Part II: Liquid chromatography-tandem mass spectrometry method development, comparison to immunoassay and pharmacokinetic study

    NARCIS (Netherlands)

    Hempen, C.M.; Gläsle-Schwarz, Liane; Kunz, Ulrich; Karst, U.

    2006-01-01

    A new liquid chromatography/atmospheric pressure chemical ionization-tandem mass spectrometry (LC/APCI-MS/MS) method with on-line sample clean-up for the determination of telmisartan in human blood plasma is presented. This technique is compared to a previously introduced enzyme-linked immunosorbent

  2. Study of the lifetime of the TL peaks of quartz: comparison of the deconvolution using the first order kinetic with the initial rise method

    International Nuclear Information System (INIS)

    RATOVONJANAHARY, A.J.F.

    2005-01-01

    Quartz is a thermoluminescent material which can be used for dating and/or for dosimetry. This material has been used since 60s for dating samples like pottery, flint, etc., but the method is still subject to some improvement. One of the problem of thermoluminescence dating is the estimation of the lifetime of the ''used peak'' . The application of the glow-curve deconvolution (GCD) technique for the analysis of a composite thermoluminescence glow curve into its individual glow peaks has been applied widely since the 80s. Many functions describing a single glow peak have been proposed. For analysing quartz behaviour, thermoluminescence glow-curve deconvolution (GCD) functions are compared for first order of kinetic. The free parameters of the GCD functions are the maximum peak intensity (I m ) and the maximum peak temperature (T m ), which can be obtained experimentally. The activation energy (E) is the additional free parameter. The lifetime (τ) of each glow peak, which is an important factor for dating, is calculated from these three parameters. For ''used'' ''peak'' lifetime analysis, GCD results are compared to those from initial rise method (IRM). Results vary fairly from method to method. [fr

  3. Three looks at users: a comparison of methods for studying digital library use. User studies, Digital libraries, Digital music libraries, Music, Information use, Information science, Contextual inquiry, Contextual design, User research, Questionnaires, Log file analysis

    Directory of Open Access Journals (Sweden)

    Mark Notess

    2004-01-01

    Full Text Available Compares three user research methods of studying real-world digital library usage within the context of the Variations and Variations2 digital music libraries at Indiana University. After a brief description of both digital libraries, each method is described and illustrated with findings from the studies. User satisfaction questionnaires were used in two studies, one of Variations (n=30 and the other of Variations2 (n=12. Second, session activity log files were examined for 175 Variations2 sessions using both quantitative and qualitative methods. The third method, contextual inquiry, is illustrated with results from field observations of four voice students' information usage patterns. The three methods are compared in terms of expertise required; time required to set up, conduct, and analyse resulting data; and the benefits derived. Further benefits are achieved with a mixed-methods approach, combining the strengths of the methods to answer questions lingering as a result of other methods.

  4. Comparison of several methods of sires evaluation for total milk ...

    African Journals Online (AJOL)

    2015-01-24

    Jan 24, 2015 ... Comparison of several methods of sires evaluation for total milk yield in a herd of Holstein cows in Yemen. F.R. Al-Samarai1,*, Y.K. Abdulrahman1, F.A. Mohammed2, F.H. Al-Zaidi2 and N.N. Al-Anbari3. 1Department of Veterinary Public Health/College of Veterinary Medicine, University of Baghdad, Iraq.

  5. Classification Method in Integrated Information Network Using Vector Image Comparison

    Directory of Open Access Journals (Sweden)

    Zhou Yuan

    2014-05-01

    Full Text Available Wireless Integrated Information Network (WMN consists of integrated information that can get data from its surrounding, such as image, voice. To transmit information, large resource is required which decreases the service time of the network. In this paper we present a Classification Approach based on Vector Image Comparison (VIC for WMN that improve the service time of the network. The available methods for sub-region selection and conversion are also proposed.

  6. Study of a 900 MW PWR by a substructuring method - Spectral response to a seismic excitation and comparison with a beam model

    International Nuclear Information System (INIS)

    Rousseau, G.; Bianchini-Burlot, B.; Bosselut, D.; Jacquart, G.; Viallet, E.

    1997-03-01

    This report presents a three dimensional Finite Element Model (FEM) of a 900 MW Pressurized Water Reactor (PWR) which is described at first: its modal behaviour is computed by a sub-structuring method based upon a Component Mode Synthesis (CMS) method. All the substructures taken into account in the model are described. One model with equivalent beams is also described. Then, different approaches to take into account the fluid/structure interaction in the different models are investigated. Results of the modal analysis of each model are compared to each other and with experimental measures. This modal analysis is then used to compute the non linear and linear response of the PWR due to a seismic excitation. (author)

  7. Study of ciclosporine blood levels in patients after kidney or bone-marrow transplantation. Comparison between the two methods, fluorescence polarization immunoassay and radioimmunoassay

    International Nuclear Information System (INIS)

    Sadeg, N.; Pham Huy, C.; Claude, J.R.; Postaire, M.; Lebrec, H.; Hamon, M.; Broyer, M.; Gagnadoux, M.F.; Fischer, A.

    1989-01-01

    The apparition of ciclosporine, immunodepressive drug, has largely improved the organ transplantations. However, the range of blood concentrations must be defined to allow the efficacity of ciclosporine therapy and to avoid toxic reactions, because there are very important variations for a same dosage according to the individuals and the diseases. Relative to the low concentrations to be determined (about one hundred ng/ml), the most useful methods for ciclosporine measurement are based on immunochemical assays. This work compares the two methods: radioimmunoassay (RIA) and fluorescence polarization immunoassay (FPIA) simultaneously performed on several hundred samples. A very significant correlation exists between the two techniques (r = 0.80). The advantages of immunofluorescent assay consists in rapidity, sensibility and facility to realize emergency analysis [fr

  8. COMPARISON OF HOLOGRAPHIC AND ITERATIVE METHODS FOR AMPLITUDE OBJECT RECONSTRUCTION

    Directory of Open Access Journals (Sweden)

    I. A. Shevkunov

    2015-01-01

    Full Text Available Experimental comparison of four methods for the wavefront reconstruction is presented. We considered two iterative and two holographic methods with different mathematical models and algorithms for recovery. The first two of these methods do not use a reference wave recording scheme that reduces requirements for stability of the installation. A major role in phase information reconstruction by such methods is played by a set of spatial intensity distributions, which are recorded as the recording matrix is being moved along the optical axis. The obtained data are used consistently for wavefront reconstruction using an iterative procedure. In the course of this procedure numerical distribution of the wavefront between the planes is performed. Thus, phase information of the wavefront is stored in every plane and calculated amplitude distributions are replaced for the measured ones in these planes. In the first of the compared methods, a two-dimensional Fresnel transform and iterative calculation in the object plane are used as a mathematical model. In the second approach, an angular spectrum method is used for numerical wavefront propagation, and the iterative calculation is carried out only between closely located planes of data registration. Two digital holography methods, based on the usage of the reference wave in the recording scheme and differing from each other by numerical reconstruction algorithm of digital holograms, are compared with the first two methods. The comparison proved that the iterative method based on 2D Fresnel transform gives results comparable with the result of common holographic method with the Fourier-filtering. It is shown that holographic method for reconstructing of the object complex amplitude in the process of the object amplitude reduction is the best among considered ones.

  9. Comparison of conventional straight and swan-neck straight catheters inserted by percutaneous method for continuous ambulatory peritoneal dialysis: a single-center study.

    Science.gov (United States)

    Singh, Shivendra; Prakash, Jai; Singh, R G; Dole, P K; Pant, Pragya

    2015-10-01

    To evaluate the incidence of mechanical and infectious complications of conventional straight catheter (SC) versus swan-neck straight catheter (SNSC) implanted by percutaneous method. We retrospectively analyzed 45 catheter insertions being done by percutaneous method from January 1, 2011, to May 31, 2014. SC was inserted in 24 patients, and SNSC was inserted in 21 patients. Baseline characteristics for the two groups were similar with respect to age, sex and diabetic nephropathy as the cause for end-stage renal disease. Incidence of mechanical and infectious complications in SNSC group was found to be low as compared to the SC group and was statistically significant (1 in 11.6 patient months vs. 1 in 14.4 patient months, p = 0.02). Catheter migration was found to be the most common mechanical complication (20 %), and peritonitis was found to be the most common infectious complication in conventional SC group (27 episodes in 420 patient months vs. 11 episodes in 333 patient months, p = 0.03). The incidence of exit site and tunnel infection rates revealed no difference between the groups. SNSC insertion by percutaneous method is associated with low mechanical and infectious complications.

  10. Quantitative comparison of two particle tracking methods in fluorescence microscopy images

    CSIR Research Space (South Africa)

    Mabaso, M

    2013-09-01

    Full Text Available that cannot be analysed efficiently by means of manual analysis. In this study we compare the performance of two computer-based tracking methods for tracking of bright particles in fluorescence microscopy image sequences. The methods under comparison are...

  11. Descriptive Qualitative Method of Evaluation from the Viewpoint of Math Teachers and Its Comparison with the Quantitative Evaluation (Giving scores) Method (A Case Study on the Primary Schools for Girls in Zone 1 of Tehran City)

    OpenAIRE

    Farnaz Ostad-Ali; Mohammad Hasan Behzadi; Ahmad Shahvarani

    2015-01-01

    In recent years, one of the most important developments which have been taking place in the primary school education system is the development of the qualitative-descriptive method of evaluating the students' achievements. The main goals of the qualitative-descriptive evaluation are improving the quality of learning and promoting the level of mental health in teaching-learning environments. Therefore, based on the the raised hypothesis, the purpose of this study is to investigate the teachers...

  12. Methods of Studying Persons.

    Science.gov (United States)

    Heinemann, Allen W.; Shontz, Franklin C.

    Conventional research strategies typically emphasize behavior-determining tendencies so strongly that the person as a whole is ignored. Research strategies for studying whole persons focus on symbolic structures, formulate specific questions in advance, study persons one at a time, use individualized measures, and regard participants as expert…

  13. Trauma outcome analysis of a Jakarta University Hospital using the TRISS method: validation and limitation in comparison with the major trauma outcome study. Trauma and Injury Severity Score

    NARCIS (Netherlands)

    Joosse, P.; Soedarmo, S.; Luitse, J. S.; Ponsen, K. J.

    2001-01-01

    In this prospective study, the TRISS methodology is used to compare trauma care at a University Hospital in Jakarta, Indonesia, with the standards reported in the Major Trauma Outcome Study (MTOS). Between February 24, 1999, and July 1, 1999, all consecutive patients with multiple and severe trauma

  14. A prospective randomized comparison between two MRI studies of the small bowel in Crohn's disease, the oral contrast method and MR enteroclysis

    International Nuclear Information System (INIS)

    Negaard, Anne; Paulsen, Vemund; Lygren, Idar; Sandvik, Leiv; Berstad, Audun E.; Borthne, Arne; Try, Kirsti; Storaas, Tryggve; Klow, Nils-Einar

    2007-01-01

    The aim was to compare bowel distension and diagnostic properties of magnetic resonance imaging of the small bowel with oral contrast (MRI per OS) with magnetic resonance enteroclysis (MRE). Forty patients with suspected Crohn's disease (CD) were examined with both MRI methods. MRI per OS was performed with a 6% mannitol solution and MRE with nasojejunal intubation and a polyethylenglycol solution. MRI protocol consisted of balanced fast field echo (B-FFE), T2 and T1 sequences with and without gadolinium. Two experienced radiologists individually evaluated bowel distension and pathological findings including wall thickness (BWT), contrast enhancement (BWE), ulcer (BWU), stenosis (BWS) and edema (EDM). The diameter of the small bowel was smaller with MRI per OS than with MRE (difference jejunum: 0.55 cm, p < 0.001; ileum: 0.35 cm, p < 0.001, terminal ileum: 0.09 cm, p = 0.08). However, CD was diagnosed with high diagnostic accuracy (sensitivity, specificity, positive and negative predictive values: MRI per OS 88%, 89%, 89%, 89%; MRE 88%, 84%, 82%, 89%) and inter-observer agreement (MRI per OS k = 0.95; MRE k = 1). In conclusion, bowel distension was inferior in MRI per OS compared to MRE. However, both methods diagnosed CD with a high diagnostic accuracy and reproducibility. (orig.)

  15. The numerical study and comparison of radial basis functions in applications of the dual reciprocity boundary element method to convection-diffusion problems

    Science.gov (United States)

    Chanthawara, Krittidej; Kaennakham, Sayan; Toutip, Wattana

    2016-02-01

    The methodology of Dual Reciprocity Boundary Element Method (DRBEM) is applied to the convection-diffusion problems and investigating its performance is our first objective of the work. Seven types of Radial Basis Functions (RBF); Linear, Thin-plate Spline, Cubic, Compactly Supported, Inverse Multiquadric, Quadratic, and that proposed by [12], were closely investigated in order to numerically compare their effectiveness drawbacks etc. and this is taken as our second objective. A sufficient number of simulations were performed covering as many aspects as possible. Varidated against both exacts and other numerical works, the final results imply strongly that the Thin-Plate Spline and Linear type of RBF are superior to others in terms of both solutions' quality and CPU-time spent while the Inverse Multiquadric seems to poorly yield the results. It is also found that DRBEM can perform relatively well at moderate level of convective force and as anticipated becomes unstable when the problem becomes more convective-dominated, as normally found in all classical mesh-dependence methods.

  16. The Comparison Study of Quadratic Infinite Beam Program on Optimization Instensity Modulated Radiation Therapy Treatment Planning (IMRTP) between Threshold and Exponential Scatter Method with CERR® In The Case of Lung Cancer

    International Nuclear Information System (INIS)

    Hardiyanti, Y; Haekal, M; Waris, A; Haryanto, F

    2016-01-01

    This research compares the quadratic optimization program on Intensity Modulated Radiation Therapy Treatment Planning (IMRTP) with the Computational Environment for Radiotherapy Research (CERR) software. We assumed that the number of beams used for the treatment planner was about 9 and 13 beams. The case used the energy of 6 MV with Source Skin Distance (SSD) of 100 cm from target volume. Dose calculation used Quadratic Infinite beam (QIB) from CERR. CERR was used in the comparison study between Gauss Primary threshold method and Gauss Primary exponential method. In the case of lung cancer, the threshold variation of 0.01, and 0.004 was used. The output of the dose was distributed using an analysis in the form of DVH from CERR. The maximum dose distributions obtained were on the target volume (PTV) Planning Target Volume, (CTV) Clinical Target Volume, (GTV) Gross Tumor Volume, liver, and skin. It was obtained that if the dose calculation method used exponential and the number of beam 9. When the dose calculation method used the threshold and the number of beam 13, the maximum dose distributions obtained were on the target volume PTV, GTV, heart, and skin. (paper)

  17. Environmental impact from different modes of transport. Method of comparison

    International Nuclear Information System (INIS)

    2002-03-01

    A prerequisite of long-term sustainable development is that activities of various kinds are adjusted to what humans and the natural world can tolerate. Transport is an activity that affects humans and the environment to a very great extent and in this project, several actors within the transport sector have together laid the foundation for the development of a comparative method to be able to compare the environmental impact at the different stages along the transport chain. The method analyses the effects of different transport concepts on the climate, noise levels, human health, acidification, land use and ozone depletion. Within the framework of the method, a calculation model has been created in Excel which acts as a basis for the comparisons. The user can choose to download the model from the Swedish EPA's on-line bookstore or order it on a floppy disk. Neither the method nor the model are as yet fully developed but our hope is that they can still be used in their present form as a basis and inspire further efforts and research in the field. In the report, we describe most of these shortcomings, the problems associated with the work and the existing development potential. This publication should be seen as the first stage in the development of a method of comparison between different modes of transport in non-monetary terms where there remains a considerable need for further development and amplification

  18. Comparison of breeding methods for forage yield in red clover

    Directory of Open Access Journals (Sweden)

    Libor Jalůvka

    2009-01-01

    Full Text Available Three methods of red clover (Trifolium pratense L. breeding for forage yield in two harvest years on locations in Bredelokke (Denmark, Hladké Životice (Czech Republic and Les Alleuds (France were compared. Three types of 46 candivars1, developed by A recurrent selection in subsequent generations (37 candivars, divided into early and late group, B polycross progenies (4 candivars and C ge­no-phe­no­ty­pic selection (5 candivars were compared. The trials were sown in 2005 and cut three times in 2006 and 2007; their evaluation is based primarily on total yield of dry matter. The candivars developed by polycross and geno-phenotypic selections gave significantly higher yields than candivars from the recurrent selection. However, the candivars developed by the methods B and C did not differ significantly. The candivars developed by these progressive methods were suitable for higher yielding and drier environment in Hladké Životice (where was the highest yield level even if averaged annual precipitation were lower by 73 and 113 mm in comparison to other locations, respectively; here was ave­ra­ge yield higher by 19 and 13% for B and C in comparison to A method. Highly significant interaction of the candivars with locations was found. It can be concluded that varieties specifically aimed to different locations by the methods B and C should be bred; also the parental entries should be selected there.

  19. Comparison of different surface quantitative analysis methods. Application to corium

    International Nuclear Information System (INIS)

    Guilbaud, N.; Blin, D.; Perodeaud, Ph.; Dugne, O.; Gueneau, Ch.

    2000-01-01

    In case of a severe hypothetical accident in a pressurized water reactor, the reactor assembly melts partially or completely. The material formed, called corium, flows out and spreads at the bottom of the reactor. To limit and control the consequences of such an accident, the specifications of the O-U-Zr basic system must be known accurately. To achieve this goal, the corium mix was melted by electron bombardment at very high temperature (3000 K) followed by quenching of the ingot in the Isabel 1 evaporator. Metallographic analyses were then required to validate the thermodynamic databases set by the Thermo-Calc software. The study consists in defining an overall surface quantitative analysis method that is fast and reliable, in order to determine the overall corium composition. The analyzed ingot originated in a [U+Fe+Y+UO 2 +ZrO 2 ) mix, with a total mass of 2253.7 grams. Several successive heating with average power were performed before a very brief plateau at very high temperature, so that the ingot was formed progressively and without any evaporation liable to modify its initial composition. The central zone of the ingot was then analyzed by qualitative and quantitative global surface methods, to yield the volume composition of the analyzed zone. Corium sample analysis happens to be very complex because of the variety and number of elements present, and also because of the presence of oxygen in a heavy element like the uranium based matrix. Three different global quantitative surface analysis methods were used: global EDS analysis (Energy Dispersive Spectrometry), with SEM, global WDS analysis (Wavelength Dispersive Spectrometry) with EPMA, and coupling of image analysis with EDS or WDS point spectroscopic analyses. The difficulties encountered during the study arose from sample preparation (corium is very sensitive to oxidation), and the choice of acquisition parameters of the images and analyses. The corium sample studied consisted of two zones displaying

  20. Description of comparison method for evaluating spatial or temporal homogeneity of environmental monitoring data

    International Nuclear Information System (INIS)

    Mecozzi, M.; Cicero, A.M.

    1995-01-01

    In this paper a comparison method to verify the homogeneity/inhomogeneity of environmental monitoring data is described. The comparison method is based on the simultaneous application of three statistical tests: One-Way ANOVA, Kruskal Wallis and One-Way IANOVA. Robust tests such as IANOVA and Kruskal Wallis can be more efficient than the usual ANOVA methods because are resistant against the presence of outliers and divergences from the normal distribution of the data. The evidences of the study are that the validation of the result about presence/absence of homogeneity in the data set is obtained when it is confirmed by two tests at least

  1. Comparison of Transmission Line Methods for Surface Acoustic Wave Modeling

    Science.gov (United States)

    Wilson, William; Atkinson, Gary

    2009-01-01

    Surface Acoustic Wave (SAW) technology is low cost, rugged, lightweight, extremely low power and can be used to develop passive wireless sensors. For these reasons, NASA is investigating the use of SAW technology for Integrated Vehicle Health Monitoring (IVHM) of aerospace structures. To facilitate rapid prototyping of passive SAW sensors for aerospace applications, SAW models have been developed. This paper reports on the comparison of three methods of modeling SAWs. The three models are the Impulse Response Method (a first order model), and two second order matrix methods; the conventional matrix approach, and a modified matrix approach that is extended to include internal finger reflections. The second order models are based upon matrices that were originally developed for analyzing microwave circuits using transmission line theory. Results from the models are presented with measured data from devices. Keywords: Surface Acoustic Wave, SAW, transmission line models, Impulse Response Method.

  2. A method comparison study between two hemoglobinometer models (Hemocue Hb 301 and Hb 201+) to measure hemoglobin concentrations and estimate anemia prevalence among women in Preah Vihear, Cambodia.

    Science.gov (United States)

    Rappaport, A I; Karakochuk, C D; Whitfield, K C; Kheang, K M; Green, T J

    2017-02-01

    Hemoglobin (Hb) concentration is often measured in global health and nutrition surveys to determine anemia prevalence using a portable hemoglobinometer such as the Hemocue® Hb 201+. More recently, a newer model was released (Hemocue Hb 301) utilizing slightly different methods to measure Hb as compared to the older model. The objective was to measure bias and concordance between Hb concentrations using the Hemocue Hb 301 and Hb 201+ models in a rural field setting. Hemoglobin (Hb) concentration was measured using one finger prick of blood (approximately 10 μL) from 175 Cambodian women (18-49 years) using three Hemocue Hb 201+ and three Hb 301 machines. Bias and concordance were measured and plotted. Overall, mean ± SD Hb concentration was 116 ± 13 g/L using the Hb 201+ and 118 ± 12 g/L using the Hb 301; and anemia prevalence (Hb < 120 g/L) was 58% (n = 102) and 58% (n = 101), respectively. Overall bias ± SD was 2.0 ± 10.5 g/L and concordance (95% CI) was 0.63 (0.54, 0.72). Despite the 2 g/L bias detected between models, anemia prevalence was very similar in both models. The two models measured anemia prevalence comparably in this population of women in rural Cambodia. © 2016 John Wiley & Sons Ltd.

  3. The comparison of placental removal methods on operative blood loss

    International Nuclear Information System (INIS)

    Waqar, F.; Fawad, A.

    2008-01-01

    On an average 1 litre of blood is lost during Caesarean Section. Many variable techniques have been tried to reduce this blood loss. Many study trials have shown the spontaneous delivery of placenta method to be superior over manual method because of reduced intra operative blood loss and reduced incidence of post operative endometritis. The main objective of our study was to compare the risk of blood loss associated with spontaneous and manual removal of the placenta during caesarean section. This study was conducted at Department of Obstetrics and Gynaecology, Islamic International Medical Complex, Islamabad from September 2004 to September 2005. All Women undergoing elective or emergency caesarean section were included in the study. Exclusion criteria were pregnancy below 37 weeks, severe maternal anaemia, and prolonged rupture of the membranes with fever, placenta praevia, placenta accreta and clotting disorders. Patients were allocated to the two groups randomly. Group A comprised of women in whom the obstetrician waited a maximum of 5 minutes till the placenta delivered spontaneously. In group B the obstetrician manually cleaved out the placenta as soon as the infant was delivered. The primary outcome measures noted were difference in haemoglobin of >2 gm/dl (preoperatively and postoperatively), time interval between delivery of baby and placenta, significant blood loss (>1000 cc), additional use of oxytocics, total operating time and blood transfusions. Data was analysed by SPSS. Statistical tests used for specific comparison were chi square-test and Student's t-test. One hundred and forty-five patients were allocated to two groups randomly. Seventy-eight patients were allocated to group A and 67 patients allocated to group B. Mean maternal age, birth weight, and total operating time were the same in two groups, but blood loss as measured by a difference in haemoglobin of greater then 2 grams/dl was statistically significant. Significant blood loss (>1000 cc

  4. Complementary biomarker-based methods for characterising Arctic sea ice conditions: A case study comparison between multivariate analysis and the PIP25 index

    Science.gov (United States)

    Köseoğlu, Denizcan; Belt, Simon T.; Smik, Lukas; Yao, Haoyi; Panieri, Giuliana; Knies, Jochen

    2018-02-01

    The discovery of IP25 as a qualitative biomarker proxy for Arctic sea ice and subsequent introduction of the so-called PIP25 index for semi-quantitative descriptions of sea ice conditions has significantly advanced our understanding of long-term paleo Arctic sea ice conditions over the past decade. We investigated the potential for classification tree (CT) models to provide a further approach to paleo Arctic sea ice reconstruction through analysis of a suite of highly branched isoprenoid (HBI) biomarkers in ca. 200 surface sediments from the Barents Sea. Four CT models constructed using different HBI assemblages revealed IP25 and an HBI triene as the most appropriate classifiers of sea ice conditions, achieving a >90% cross-validated classification rate. Additionally, lower model performance for locations in the Marginal Ice Zone (MIZ) highlighted difficulties in characterisation of this climatically-sensitive region. CT model classification and semi-quantitative PIP25-derived estimates of spring sea ice concentration (SpSIC) for four downcore records from the region were consistent, although agreement between proxy and satellite/observational records was weaker for a core from the west Svalbard margin, likely due to the highly variable sea ice conditions. The automatic selection of appropriate biomarkers for description of sea ice conditions, quantitative model assessment, and insensitivity to the c-factor used in the calculation of the PIP25 index are key attributes of the CT approach, and we provide an initial comparative assessment between these potentially complementary methods. The CT model should be capable of generating longer-term temporal shifts in sea ice conditions for the climatically sensitive Barents Sea.

  5. Isotopic composition of pore water in the Tournemire argilites (Aveyron, France): inter-comparison study of analytical methods and relations with petrophysical parameters

    International Nuclear Information System (INIS)

    Altinier, M.V.

    2006-06-01

    Stable isotope profiles of pore water in argillaceous rocks are used to characterize fluid migration through these rocks. However, the very low water contents, less than 5% by wet weight, and the small pore sizes (<10 nm) make difficult the access to pore water. In order to assess the representativeness of stable isotopes data in pore water from Tournemire shale (IRSN experimental facility), we made a comparative study by using vacuum distillation at 50 deg. C and 150 deg. C, diffusion in liquid phase and diffusive exchange in vapour phase, together with a study of petrophysical and mineralogical properties of the rock. The results show a good agreement between the water contents determined by heating and vacuum distillation at 150 deg. C and by equilibration techniques. On the other hand, vacuum distillation at 50 deg. C allows to extract less than 90% of the extractable water by heating at 150 deg. C; leading to a depletion in heavy isotopes of extracted water, which can be corrected by using a Rayleigh-type model. Finally, we studied a perpendicular profile to a fracture in order to determine the origin of heavy isotope enrichment of pore water that was observed, in previous works, in the vicinity of fractures (less than one meter). It seems that water content, which increases near the fracture, associated with a more important proportion of bigger pores (φ ∼ 10 - 180 nm), would be at the origin of the isotopic anomalies determined by vacuum distillation at 50 deg. C. Preponderance of bigger pores near the fractures would facilitate mobilization of pore water and its extraction by vacuum distillation at 50 deg. C, reducing the effects of incomplete distillation. (author)

  6. An algebraic topological method for multimodal brain networks comparison

    Directory of Open Access Journals (Sweden)

    Tiago eSimas

    2015-07-01

    Full Text Available Understanding brain connectivity is one of the most important issues in neuroscience. Nonetheless, connectivity data can reflect either functional relationships of brain activities or anatomical connections between brain areas. Although both representations should be related, this relationship is not straightforward. We have devised a powerful method that allows different operations between networks that share the same set of nodes, by embedding them in a common metric space, enforcing transitivity to the graph topology. Here, we apply this method to construct an aggregated network from a set of functional graphs, each one from a different subject. Once this aggregated functional network is constructed, we use again our method to compare it with the structural connectivity to identify particular brain regions that differ in both modalities (anatomical and functional. Remarkably, these brain regions include functional areas that form part of the classical resting state networks. We conclude that our method -based on the comparison of the aggregated functional network- reveals some emerging features that could not be observed when the comparison is performed with the classical averaged functional network.

  7. A Comparison of Methods and Results in Recruiting White and Black Women into Reproductive Studies: The MMC-PSU Cooperative Center on Reproduction Experience

    Science.gov (United States)

    Sweet, Stephanie; Legro, Richard S; Coney, PonJola

    2008-01-01

    Establishing a holistic approach for the enrollment of subjects into clinical trials that includes strategies for the recruitment of non-traditional and minority populations has been an elusive task. The existence of such a design, that is understood and embraced by investigators and the target communities, would streamline the current level of commitment of time, energy and resources. This is necessary to successfully encourage individual and community participation in research studies. The Center for Research in Reproduction at Meharry set out to recruit a large number of African American women volunteers of reproductive age into clinical trials. The experience, of recruiting volunteers from the African American community for clinical trials in the Meharry Medical College/Pennsylvania State University (MMC/PSU)'s Cooperative Center for Research in Reproduction at Meharry, is presented. PMID:18082470

  8. Comparison of manual and automatic segmentation methods for brain structures in the presence of space-occupying lesions: a multi-expert study

    International Nuclear Information System (INIS)

    Deeley, M A; Cmelak, A J; Malcolm, A W; Moretti, L; Jaboin, J; Niermann, K; Yang, Eddy S; Yu, David S; Ding, G X; Chen, A; Datteri, R; Noble, J H; Dawant, B M; Donnelly, E F; Yei, F; Koyama, T

    2011-01-01

    The purpose of this work was to characterize expert variation in segmentation of intracranial structures pertinent to radiation therapy, and to assess a registration-driven atlas-based segmentation algorithm in that context. Eight experts were recruited to segment the brainstem, optic chiasm, optic nerves, and eyes, of 20 patients who underwent therapy for large space-occupying tumors. Performance variability was assessed through three geometric measures: volume, Dice similarity coefficient, and Euclidean distance. In addition, two simulated ground truth segmentations were calculated via the simultaneous truth and performance level estimation algorithm and a novel application of probability maps. The experts and automatic system were found to generate structures of similar volume, though the experts exhibited higher variation with respect to tubular structures. No difference was found between the mean Dice similarity coefficient (DSC) of the automatic and expert delineations as a group at a 5% significance level over all cases and organs. The larger structures of the brainstem and eyes exhibited mean DSC of approximately 0.8-0.9, whereas the tubular chiasm and nerves were lower, approximately 0.4-0.5. Similarly low DSCs have been reported previously without the context of several experts and patient volumes. This study, however, provides evidence that experts are similarly challenged. The average maximum distances (maximum inside, maximum outside) from a simulated ground truth ranged from (-4.3, +5.4) mm for the automatic system to (-3.9, +7.5) mm for the experts considered as a group. Over all the structures in a rank of true positive rates at a 2 mm threshold from the simulated ground truth, the automatic system ranked second of the nine raters. This work underscores the need for large scale studies utilizing statistically robust numbers of patients and experts in evaluating quality of automatic algorithms.

  9. Demographic analysis, a comparison of the jackknife and bootstrap methods, and predation projection: a case study of Chrysopa pallens (Neuroptera: Chrysopidae).

    Science.gov (United States)

    Yu, Ling-Yuan; Chen, Zhen-Zhen; Zheng, Fang-Qiang; Shi, Ai-Ju; Guo, Ting-Ting; Yeh, Bao-Hua; Chi, Hsin; Xu, Yong-Yu

    2013-02-01

    The life table of the green lacewing, Chrysopa pallens (Rambur), was studied at 22 degrees C, a photoperiod of 15:9 (L:D) h, and 80% relative humidity in the laboratory. The raw data were analyzed using the age-stage, two-sex life table. The intrinsic rate of increase (r), the finite rate of increase (lambda), the net reproduction rate (R0), and the mean generation time (T) of Ch. pallens were 0.1258 d(-1), 1.1340 d(-1), 241.4 offspring and 43.6 d, respectively. For the estimation of the means, variances, and SEs of the population parameters, we compared the jackknife and bootstrap techniques. Although similar values of the means and SEs were obtained with both techniques, significant differences were observed in the frequency distribution and variances of all parameters. The jackknife technique will result in a zero net reproductive rate upon the omission of a male, an immature death, or a nonreproductive female. This result represents, however, a contradiction because an intrinsic rate of increase exists in this situation. Therefore, we suggest that the jackknife technique should not be used for the estimation of population parameters. In predator-prey interactions, the nonpredatory egg and pupal stages of the predator are time refuges for the prey, and the pest population can grow during these times. In this study, a population projection based on the age-stage, two-sex life table is used to determine the optimal interval between releases to fill the predation gaps and maintain the predatory capacity of the control agent.

  10. Comparison of methods for recruiting and engaging parents in online interventions: study protocol for the Cry Baby infant sleep and settling program.

    Science.gov (United States)

    Cook, Fallon; Seymour, Monique; Giallo, Rebecca; Cann, Warren; Nicholson, Jan M; Green, Julie; Hiscock, Harriet

    2015-11-10

    Anticipatory guidance around the management of sleep and crying problems in early infancy has been shown to improve both infant behaviour and parent symptoms of postnatal depression. Digital technology offers platforms for making such programs widely available in a cost-efficient manner. However, it remains unclear who accesses online parenting advice and in particular, whether the parents who would most benefit are represented amongst users. It is also unknown whether the uptake of online programs can be improved by health professional recommendations, or whether parents require additional prompts and reminders to use the program. In this study we aim to: (1) determine whether weekly email prompts increase engagement with and use of a brief online program about infant sleeping and crying, (2) determine whether encouragement from a maternal and child health nurse promotes greater engagement with and use of the program, (3) examine who uses a brief online program about infant sleeping and crying; and, (4) examine the psychosocial characteristics of participants. This study is a randomised, parallel group, superiority trial, with all participating primary carers of infants aged 2 to 12 weeks, receiving access to the online program. Two modes of recruitment will be compared: recruitment via an online notice published on a non-commercial, highly credible and evidence-based website for parents and carers and via the parent's Maternal and Child Health nurse. After baseline assessment, parents will be randomised to one of two support conditions: online program alone or online program plus weekly email prompts. Follow up data will be collected at 4 months of infant age. Results from this trial will indicate whether involvement from a health professional, and/or ongoing email contact is necessary to engage parents in a brief online intervention, and promote parental use of strategies suggested within the program. Results of this trial will inform the development of

  11. A comparison of surveillance methods for small incidence rates

    Energy Technology Data Exchange (ETDEWEB)

    Sego, Landon H.; Woodall, William H.; Reynolds, Marion R.

    2008-05-15

    A number of methods have been proposed to detect an increasing shift in the incidence rate of a rare health event, such as a congenital malformation. Among these are the Sets method, two modifcations of the Sets method, and the CUSUM method based on the Poisson distribution. We consider the situation where data are observed as a sequence of Bernoulli trials and propose the Bernoulli CUSUM chart as a desirable method for the surveillance of rare health events. We compare the performance of the Sets method and its modifcations to the Bernoulli CUSUM chart under a wide variety of circumstances. Chart design parameters were chosen to satisfy a minimax criteria.We used the steady- state average run length to measure chart performance instead of the average run length which was used in nearly all previous comparisons involving the Sets method or its modifcations. Except in a very few instances, we found that the Bernoulli CUSUM chart has better steady-state average run length performance than the Sets method and its modifcations for the extensive number of cases considered.

  12. A comparison of ancestral state reconstruction methods for quantitative characters.

    Science.gov (United States)

    Royer-Carenzi, Manuela; Didier, Gilles

    2016-09-07

    Choosing an ancestral state reconstruction method among the alternatives available for quantitative characters may be puzzling. We present here a comparison of seven of them, namely the maximum likelihood, restricted maximum likelihood, generalized least squares under Brownian, Brownian-with-trend and Ornstein-Uhlenbeck models, phylogenetic independent contrasts and squared parsimony methods. A review of the relations between these methods shows that the maximum likelihood, the restricted maximum likelihood and the generalized least squares under Brownian model infer the same ancestral states and can only be distinguished by the distributions accounting for the reconstruction uncertainty which they provide. The respective accuracy of the methods is assessed over character evolution simulated under a Brownian motion with (and without) directional or stabilizing selection. We give the general form of ancestral state distributions conditioned on leaf states under the simulation models. Ancestral distributions are used first, to give a theoretical lower bound of the expected reconstruction error, and second, to develop an original evaluation scheme which is more efficient than comparing the reconstructed and the simulated states. Our simulations show that: (i) the distributions of the reconstruction uncertainty provided by the methods generally make sense (some more than others); (ii) it is essential to detect the presence of an evolutionary trend and to choose a reconstruction method accordingly; (iii) all the methods show good performances on characters under stabilizing selection; (iv) without trend or stabilizing selection, the maximum likelihood method is generally the most accurate. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Improving Assessment of Lifetime Solar Ultraviolet Radiation Exposure in Epidemiologic Studies: Comparison of Ultraviolet Exposure Assessment Methods in a Nationwide United States Occupational Cohort.

    Science.gov (United States)

    Little, Mark P; Tatalovich, Zaria; Linet, Martha S; Fang, Michelle; Kendall, Gerald M; Kimlin, Michael G

    2018-06-13

    Solar ultraviolet radiation is the primary risk factor for skin cancers and sun-related eye disorders. Estimates of individual ambient ultraviolet irradiance derived from ground-based solar measurements and from satellite measurements have rarely been compared. Using self-reported residential history from 67,189 persons in a nationwide occupational US radiologic technologists cohort, we estimated ambient solar irradiance using data from ground-based meters and noontime satellite measurements. The mean distance-moved from city of longest residence in childhood increased from 137.6 km at ages 13-19 to 870.3 km at ages ≥65, with corresponding increases in absolute latitude-difference moved. At ages 20/40/60/80, the Pearson/Spearman correlation coefficients of ground-based and satellite-derived solar potential ultraviolet exposure, using irradiance and cumulative radiant-exposure metrics, were high (=0.87-0.92). There was also moderate correlation (Pearson/Spearman correlation coefficients=0.51-0.60) between irradiance at birth and at last-known address, for ground-based and satellite data. Satellite-based lifetime estimates of ultraviolet radiation were generally 14-15% lower than ground-based estimates, albeit with substantial uncertainties, possibly because ground-based estimates incorporate fluctuations in cloud and ozone, which are incompletely incorporated in the single noontime satellite-overpass ultraviolet value. If confirmed elsewhere, the findings suggest that ground-based estimates may improve exposure-assessment accuracy and potentially provide new insights into ultraviolet-radiation-disease relationships in epidemiologic studies. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  14. A Comparison of Surface Acoustic Wave Modeling Methods

    Science.gov (United States)

    Wilson, W. c.; Atkinson, G. M.

    2009-01-01

    Surface Acoustic Wave (SAW) technology is low cost, rugged, lightweight, extremely low power and can be used to develop passive wireless sensors. For these reasons, NASA is investigating the use of SAW technology for Integrated Vehicle Health Monitoring (IVHM) of aerospace structures. To facilitate rapid prototyping of passive SAW sensors for aerospace applications, SAW models have been developed. This paper reports on the comparison of three methods of modeling SAWs. The three models are the Impulse Response Method a first order model, and two second order matrix methods; the conventional matrix approach, and a modified matrix approach that is extended to include internal finger reflections. The second order models are based upon matrices that were originally developed for analyzing microwave circuits using transmission line theory. Results from the models are presented with measured data from devices.

  15. Comparison of Video Steganography Methods for Watermark Embedding

    Directory of Open Access Journals (Sweden)

    Griberman David

    2016-05-01

    Full Text Available The paper focuses on the comparison of video steganography methods for the purpose of digital watermarking in the context of copyright protection. Four embedding methods that use Discrete Cosine and Discrete Wavelet Transforms have been researched and compared based on their embedding efficiency and fidelity. A video steganography program has been developed in the Java programming language with all of the researched methods implemented for experiments. The experiments used 3 video containers with different amounts of movement. The impact of the movement has been addressed in the paper as well as the ways of potential improvement of embedding efficiency using adaptive embedding based on the movement amount. Results of the research have been verified using a survey with 17 participants.

  16. A comparison of methods for evaluating structure during ship collisions

    International Nuclear Information System (INIS)

    Ammerman, D.J.; Daidola, J.C.

    1996-01-01

    A comparison is provided of the results of various methods for evaluating structure during a ship-to-ship collision. The baseline vessel utilized in the analyses is a 67.4 meter in length displacement hull struck by an identical vessel traveling at speeds ranging from 10 to 30 knots. The structural response of the struck vessel and motion of both the struck and striking vessels are assessed by finite element analysis. These same results are then compared to predictions utilizing the open-quotes Tanker Structural Analysis for Minor Collisionsclose quotes (TSAMC) Method, the Minorsky Method, the Haywood Collision Process, and comparison to full-scale tests. Consideration is given to the nature of structural deformation, absorbed energy, penetration, rigid body motion, and virtual mass affecting the hydrodynamic response. Insights are provided with regard to the calibration of the finite element model which was achievable through utilizing the more empirical analyses and the extent to which the finite element analysis is able to simulate the entire collision event. 7 refs., 8 figs., 4 tabs

  17. A new comparison method for dew-point generators

    Science.gov (United States)

    Heinonen, Martti

    1999-12-01

    A new method for comparing dew-point generators was developed at the Centre for Metrology and Accreditation. In this method, the generators participating in a comparison are compared with a transportable saturator unit using a dew-point comparator. The method was tested by constructing a test apparatus and by comparing it with the MIKES primary dew-point generator several times in the dew-point temperature range from -40 to +75 °C. The expanded uncertainty (k = 2) of the apparatus was estimated to be between 0.05 and 0.07 °C and the difference between the comparator system and the generator is well within these limits. In particular, all of the results obtained in the range below 0 °C are within ±0.03 °C. It is concluded that a new type of a transfer standard with characteristics most suitable for dew-point comparisons can be developed on the basis of the principles presented in this paper.

  18. A comparison of Nodal methods in neutron diffusion calculations

    Energy Technology Data Exchange (ETDEWEB)

    Tavron, Barak [Israel Electric Company, Haifa (Israel) Nuclear Engineering Dept. Research and Development Div.

    1996-12-01

    The nuclear engineering department at IEC uses in the reactor analysis three neutron diffusion codes based on nodal methods. The codes, GNOMERl, ADMARC2 and NOXER3 solve the neutron diffusion equation to obtain flux and power distributions in the core. The resulting flux distributions are used for the furl cycle analysis and for fuel reload optimization. This work presents a comparison of the various nodal methods employed in the above codes. Nodal methods (also called Coarse-mesh methods) have been designed to solve problems that contain relatively coarse areas of homogeneous composition. In the nodal method parts of the equation that present the state in the homogeneous area are solved analytically while, according to various assumptions and continuity requirements, a general solution is sought out. Thus efficiency of the method for this kind of problems, is very high compared with the finite element and finite difference methods. On the other hand, using this method one can get only approximate information about the node vicinity (or coarse-mesh area, usually a feel assembly of a 20 cm size). These characteristics of the nodal method make it suitable for feel cycle analysis and reload optimization. This analysis requires many subsequent calculations of the flux and power distributions for the feel assemblies while there is no need for detailed distribution within the assembly. For obtaining detailed distribution within the assembly methods of power reconstruction may be applied. However homogenization of feel assembly properties, required for the nodal method, may cause difficulties when applied to fuel assemblies with many absorber rods, due to exciting strong neutron properties heterogeneity within the assembly. (author).

  19. Comparison of artificial inoculation methods for studying ...

    African Journals Online (AJOL)

    divya

    2013-05-01

    May 1, 2013 ... atomizer; injection of spore suspension into the plants surface or into the intercellular air spaces of a ... Seeds of brown mustard B. juncea were sown in plastic inserts. (7.5 x 5 cm; 2 seeds per insert) containing ... system of the leaf should be avoided for injection. Detached leaves were kept in sealed Petri ...

  20. Comparison of two uncertainty dressing methods: SAD VS DAD

    Science.gov (United States)

    Chardon, Jérémy; Mathevet, Thibault; Le-Lay, Matthieu; Gailhard, Joël

    2014-05-01

    Hydrological Ensemble Prediction Systems (HEPSs) allow a better representation of meteorological and hydrological forecast uncertainties and improve human expertise of hydrological forecasts. An operational HEPS has been developed at EDF (French Producer of Electricity) since 2008 and is being used since 2010 on a hundred of watersheds in France. Depending on the hydro-meteorological situation, streamflow forecasts could be issued on a daily basis and are used to help dam management operations during floods or dam works within the river. A part of this HEPS is characterized by a streamflow ensemble post-processing, where a large human expertise is solicited. The aim of post-processing methods is to achieve better overall performances, by dressing hydrological ensemble forecasts with hydrological model uncertainties. The present study compares two post-processing methods, which are based on a logarithmic representation of the residuals distribution of the Rainfall-Runoff (RR) model, based on "perfect" forcing forecasts - i.e. forecasts with observed meteorological variables as inputs. The only difference between the two post-processing methods lies in the sampling of the perfect forcing forecasts for the estimation of the residuals statistics: (i) a first method, referred here as Statistical Analogy Dressing (SAD) model and used for operational HEPS, estimates beforehand the statistics of the residuals by streamflow sub-samples of quantile class and lead-time, since RR model residuals are not homoscedastic. (ii) an alternative method, referred as Dynamical Analogy Dressing (DAD) model, estimates the statistics of the residuals using the N most similar perfect forcing forecasts. The selection of this N forecasts is based on streamflow range and variation. On a set of 20 watersheds used for operational forecasts, both models were evaluated with perfect forcing forecasts and with ensemble forecasts. Results show that both approaches ensure a good post-processing of

  1. Comparison of three retail data communication and transmission methods

    Directory of Open Access Journals (Sweden)

    MA Yue

    2016-04-01

    Full Text Available With the rapid development of retail trade,the type and complexity of data keep increasing,and single data file size has a great difference between each other.How to realize an accurate,real-time and efficient data transmission based on a fixed cost is an important problem.Regarding the problem of effective transmission for business data files,this article implements analysis and comparison on 3 existing data transmission methods,considering the requirements on aspects like function in enterprise data communication system,we get a conclusion that which method can both meet the enterprise daily business development requirement better and have good extension ability.

  2. National comparison on volume sample activity measurement methods

    International Nuclear Information System (INIS)

    Sahagia, M.; Grigorescu, E.L.; Popescu, C.; Razdolescu, C.

    1992-01-01

    A national comparison on volume sample activity measurements methods may be regarded as a step toward accomplishing the traceability of the environmental and food chain activity measurements to national standards. For this purpose, the Radionuclide Metrology Laboratory has distributed 137 Cs and 134 Cs water-equivalent solid standard sources to 24 laboratories having responsibilities in this matter. Every laboratory has to measure the activity of the received source(s) by using its own standards, equipment and methods and report the obtained results to the organizer. The 'measured activities' will be compared with the 'true activities'. A final report will be issued, which plans to evaluate the national level of precision of such measurements and give some suggestions for improvement. (Author)

  3. Enzyme sequence similarity improves the reaction alignment method for cross-species pathway comparison

    Energy Technology Data Exchange (ETDEWEB)

    Ovacik, Meric A. [Chemical and Biochemical Engineering Department, Rutgers University, Piscataway, NJ 08854 (United States); Androulakis, Ioannis P., E-mail: yannis@rci.rutgers.edu [Chemical and Biochemical Engineering Department, Rutgers University, Piscataway, NJ 08854 (United States); Biomedical Engineering Department, Rutgers University, Piscataway, NJ 08854 (United States)

    2013-09-15

    Pathway-based information has become an important source of information for both establishing evolutionary relationships and understanding the mode of action of a chemical or pharmaceutical among species. Cross-species comparison of pathways can address two broad questions: comparison in order to inform evolutionary relationships and to extrapolate species differences used in a number of different applications including drug and toxicity testing. Cross-species comparison of metabolic pathways is complex as there are multiple features of a pathway that can be modeled and compared. Among the various methods that have been proposed, reaction alignment has emerged as the most successful at predicting phylogenetic relationships based on NCBI taxonomy. We propose an improvement of the reaction alignment method by accounting for sequence similarity in addition to reaction alignment method. Using nine species, including human and some model organisms and test species, we evaluate the standard and improved comparison methods by analyzing glycolysis and citrate cycle pathways conservation. In addition, we demonstrate how organism comparison can be conducted by accounting for the cumulative information retrieved from nine pathways in central metabolism as well as a more complete study involving 36 pathways common in all nine species. Our results indicate that reaction alignment with enzyme sequence similarity results in a more accurate representation of pathway specific cross-species similarities and differences based on NCBI taxonomy.

  4. Enzyme sequence similarity improves the reaction alignment method for cross-species pathway comparison

    International Nuclear Information System (INIS)

    Ovacik, Meric A.; Androulakis, Ioannis P.

    2013-01-01

    Pathway-based information has become an important source of information for both establishing evolutionary relationships and understanding the mode of action of a chemical or pharmaceutical among species. Cross-species comparison of pathways can address two broad questions: comparison in order to inform evolutionary relationships and to extrapolate species differences used in a number of different applications including drug and toxicity testing. Cross-species comparison of metabolic pathways is complex as there are multiple features of a pathway that can be modeled and compared. Among the various methods that have been proposed, reaction alignment has emerged as the most successful at predicting phylogenetic relationships based on NCBI taxonomy. We propose an improvement of the reaction alignment method by accounting for sequence similarity in addition to reaction alignment method. Using nine species, including human and some model organisms and test species, we evaluate the standard and improved comparison methods by analyzing glycolysis and citrate cycle pathways conservation. In addition, we demonstrate how organism comparison can be conducted by accounting for the cumulative information retrieved from nine pathways in central metabolism as well as a more complete study involving 36 pathways common in all nine species. Our results indicate that reaction alignment with enzyme sequence similarity results in a more accurate representation of pathway specific cross-species similarities and differences based on NCBI taxonomy

  5. Experience from the comparison of two PSA-studies

    International Nuclear Information System (INIS)

    Holmberg, J.; Pulkkinen, U.

    2001-03-01

    Two probabilistic safety assessments (PSA) made for nearly identical reactors units (Forsmark 3 and Oskarshamn 3) have been compared. Two different analysis teams made the PSAs, and the analyses became quite different. The goal of the study is to identify, clarify and explain differences between PSA-studies. The purpose is to understand limitations and uncertainties in PSA, to explain reasons for differences between PSA-studies, and to give recommendations for comparison of PSA-studies and for improving the PSA-methodology. The reviews have been made by reading PSA-documentation, using the computer model and interviewing persons involved in the projects. The method and findings have been discussed within the project group. Both the PSA-project and various parts in the PSA-model have been reviewed. A major finding was that the two projects had different purpose and thus had different resources, scope and even methods in their study. The study shows that comparison of PSA results from different plants is normally not meaningful. It takes a very deep knowledge of the PSA studies to make a comparison of the results and usually one has to ensure that the compared studies have the same scope and are based on the same analysis methods. Harmonisation of the PSA-methodology is recommended in the presentation of results, presentation of methods, scope main limitation and assumption, and definitions for end states, initiating events and common cause failures. This would facilitate the comparison of the studies. Methods for validation of PSA for different application areas should be developed. The developed PSA review standards can be applied for a general validation of a study. The most important way to evaluate the real feasibility of PSA can take place only with practical applications. The PSA-documentation and models can be developed to facilitate the communication between PSA-experts and users. In any application consultation with the PSA-expert is however needed. Many

  6. Comparison of the dose evaluation methods for criticality accident

    International Nuclear Information System (INIS)

    Shimizu, Yoshio; Oka, Tsutomu

    2004-01-01

    The improvement of the dose evaluation method for criticality accidents is important to rationalize design of the nuclear fuel cycle facilities. The source spectrums of neutron and gamma ray of a criticality accident depend on the condition of the source, its materials, moderation, density and so on. The comparison of the dose evaluation methods for a criticality accident is made. Some methods, which are combination of criticality calculation and shielding calculation, are proposed. Prompt neutron and gamma ray doses from nuclear criticality of some uranium systems have been evaluated as the Nuclear Criticality Slide Rule. The uranium metal source (unmoderated system) and the uranyl nitrate solution source (moderated system) in the rule are evaluated by some calculation methods, which are combinations of code and cross section library, as follows: (a) SAS1X (ENDF/B-IV), (b) MCNP4C (ENDF/B-VI)-ANISN (DLC23E or JSD120), (c) MCNP4C-MCNP4C (ENDF/B-VI). They have consisted of criticality calculation and shielding calculation. These calculation methods are compared about the tissue absorbed dose and the spectrums at 2 m from the source. (author)

  7. The Comparison Study of Six University Archives

    Directory of Open Access Journals (Sweden)

    Chun-Fen Liu

    2004-03-01

    Full Text Available The university archives is not only the extension of a building, but also includes the archival records, archivists and equipments. The university archives is the historical memory of a university, which could let people to predict the future by reviewing the past. The university archives has abundant collections, both teachers and students can review history of this university. This paper mainly compares six university archives of Taiwan, and the interviewing method is used in this research. After comparison of the six university archives, we have found the six university archives have different organizational structures, budgets, and functions. Finally the authors propose some suggestions.[Article content in Chinese

  8. Comparison of five actigraphy scoring methods with bipolar disorder.

    Science.gov (United States)

    Boudebesse, Carole; Leboyer, Marion; Begley, Amy; Wood, Annette; Miewald, Jean; Hall, Martica; Frank, Ellen; Kupfer, David; Germain, Anne

    2013-01-01

    The goal of this study was to compare 5 actigraphy scoring methods in a sample of 18 remitted patients with bipolar disorder. Actigraphy records were processed using five different scoring methods relying on the sleep diary; the event-marker; the software-provided automatic algorithm; the automatic algorithm supplemented by the event-marker; visual inspection (VI) only. The algorithm and the VI methods differed from the other methods for many actigraphy parameters of interest. Particularly, the algorithm method yielded longer sleep duration, and the VI method yielded shorter sleep latency compared to the other methods. The present findings provide guidance for the selection of signal processing method based on sleep parameters of interest, time-cue sources and availability, and related scoring time costs for the study.

  9. Comparison of methods used for estimating pharmacist counseling behaviors.

    Science.gov (United States)

    Schommer, J C; Sullivan, D L; Wiederholt, J B

    1994-01-01

    To compare the rates reported for provision of types of information conveyed by pharmacists among studies for which different methods of estimation were used and different dispensing situations were studied. Empiric studies conducted in the US, reported from 1982 through 1992, were selected from International Pharmaceutical Abstracts, MEDLINE, and noncomputerized sources. Empiric studies were selected for review if they reported the provision of at least three types of counseling information. Four components of methods used for estimating pharmacist counseling behaviors were extracted and summarized in a table: (1) sample type and area, (2) sampling unit, (3) sample size, and (4) data collection method. In addition, situations that were investigated in each study were compiled. Twelve studies met our inclusion criteria. Patients were interviewed via telephone in four studies and were surveyed via mail in two studies. Pharmacists were interviewed via telephone in one study and surveyed via mail in two studies. For three studies, researchers visited pharmacy sites for data collection using the shopper method or observation method. Studies with similar methods and situations provided similar results. Data collected by using patient surveys, pharmacist surveys, and observation methods can provide useful estimations of pharmacist counseling behaviors if researchers measure counseling for specific, well-defined dispensing situations.

  10. A comparison of three clustering methods for finding subgroups in MRI, SMS or clinical data

    DEFF Research Database (Denmark)

    Kent, Peter; Jensen, Rikke K; Kongsted, Alice

    2014-01-01

    ). There is a scarcity of head-to-head comparisons that can inform the choice of which clustering method might be suitable for particular clinical datasets and research questions. Therefore, the aim of this study was to perform a head-to-head comparison of three commonly available methods (SPSS TwoStep CA, Latent Gold...... LCA and SNOB LCA). METHODS: The performance of these three methods was compared: (i) quantitatively using the number of subgroups detected, the classification probability of individuals into subgroups, the reproducibility of results, and (ii) qualitatively using subjective judgments about each program...... classify individuals into those subgroups. CONCLUSIONS: Our subjective judgement was that Latent Gold offered the best balance of sensitivity to subgroups, ease of use and presentation of results with these datasets but we recognise that different clustering methods may suit other types of data...

  11. Comparison of electric field exposure measurement methods under power lines

    International Nuclear Information System (INIS)

    Korpinen, L.; Kuisti, H.; Tarao, H.; Paeaekkoenen, R.; Elovaara, J.

    2014-01-01

    The object of the study was to investigate extremely low frequency (ELF) electric field exposure measurement methods under power lines. The authors compared two different methods under power lines: in Method A, the sensor was placed on a tripod; and Method B required the measurer to hold the meter horizontally so that the distance from him/her was at least 1.5 m. The study includes 20 measurements in three places under 400 kV power lines. The authors used two commercial three-axis meters, EFA-3 and EFA-300. In statistical analyses, they did not find significant differences between Methods A and B. However, in the future, it is important to take into account that measurement methods can, in some cases, influence ELF electric field measurement results, and it is important to report the methods used so that it is possible to repeat the measurements. (authors)

  12. Comparison of hardenability calculation methods of the heat-treatable constructional steels

    Energy Technology Data Exchange (ETDEWEB)

    Dobrzanski, L.A.; Sitek, W. [Division of Tool Materials and Computer Techniques in Metal Science, Silesian Technical University, Gliwice (Poland)

    1995-12-31

    Evaluation has been made of the consistency of calculation of the hardenability curves of the selected heat-treatable alloyed constructional steels with the experimental data. The study has been conducted basing on the analysis of present state of knowledge on hardenability calculation employing the neural network methods. Several calculation examples and comparison of the consistency of calculation methods employed are included. (author). 35 refs, 2 figs, 3 tabs.

  13. Specific activity measurement of 64Cu: A comparison of methods

    International Nuclear Information System (INIS)

    Mastren, Tara; Guthrie, James; Eisenbeis, Paul; Voller, Tom; Mebrahtu, Efrem; Robertson, J. David; Lapi, Suzanne E.

    2014-01-01

    Effective specific activity of 64 Cu (amount of radioactivity per µmol metal) is important in order to determine purity of a particular 64 Cu lot and to assist in optimization of the purification process. Metal impurities can affect effective specific activity and therefore it is important to have a simple method that can measure trace amounts of metals. This work shows that ion chromatography (IC) yields similar results to ICP mass spectrometry for copper, nickel and iron contaminants in 64 Cu production solutions. - Highlights: • Comparison of TETA titration, ICP mass spectrometry, and ion chromatography to measure specific activity. • Validates ion chromatography by using ICP mass spectrometry as the “gold standard”. • Shows different types and amounts of metal impurities present in 64 Cu

  14. Comparison of deterministic and Monte Carlo methods in shielding design.

    Science.gov (United States)

    Oliveira, A D; Oliveira, C

    2005-01-01

    In shielding calculation, deterministic methods have some advantages and also some disadvantages relative to other kind of codes, such as Monte Carlo. The main advantage is the short computer time needed to find solutions while the disadvantages are related to the often-used build-up factor that is extrapolated from high to low energies or with unknown geometrical conditions, which can lead to significant errors in shielding results. The aim of this work is to investigate how good are some deterministic methods to calculating low-energy shielding, using attenuation coefficients and build-up factor corrections. Commercial software MicroShield 5.05 has been used as the deterministic code while MCNP has been used as the Monte Carlo code. Point and cylindrical sources with slab shield have been defined allowing comparison between the capability of both Monte Carlo and deterministic methods in a day-by-day shielding calculation using sensitivity analysis of significant parameters, such as energy and geometrical conditions.

  15. Comparison of deterministic and Monte Carlo methods in shielding design

    International Nuclear Information System (INIS)

    Oliveira, A. D.; Oliveira, C.

    2005-01-01

    In shielding calculation, deterministic methods have some advantages and also some disadvantages relative to other kind of codes, such as Monte Carlo. The main advantage is the short computer time needed to find solutions while the disadvantages are related to the often-used build-up factor that is extrapolated from high to low energies or with unknown geometrical conditions, which can lead to significant errors in shielding results. The aim of this work is to investigate how good are some deterministic methods to calculating low-energy shielding, using attenuation coefficients and build-up factor corrections. Commercial software MicroShield 5.05 has been used as the deterministic code while MCNP has been used as the Monte Carlo code. Point and cylindrical sources with slab shield have been defined allowing comparison between the capability of both Monte Carlo and deterministic methods in a day-by-day shielding calculation using sensitivity analysis of significant parameters, such as energy and geometrical conditions. (authors)

  16. Instrumental and statistical methods for the comparison of class evidence

    Science.gov (United States)

    Liszewski, Elisa Anne

    Trace evidence is a major field within forensic science. Association of trace evidence samples can be problematic due to sample heterogeneity and a lack of quantitative criteria for comparing spectra or chromatograms. The aim of this study is to evaluate different types of instrumentation for their ability to discriminate among samples of various types of trace evidence. Chemometric analysis, including techniques such as Agglomerative Hierarchical Clustering, Principal Components Analysis, and Discriminant Analysis, was employed to evaluate instrumental data. First, automotive clear coats were analyzed by using microspectrophotometry to collect UV absorption data. In total, 71 samples were analyzed with classification accuracy of 91.61%. An external validation was performed, resulting in a prediction accuracy of 81.11%. Next, fiber dyes were analyzed using UV-Visible microspectrophotometry. While several physical characteristics of cotton fiber can be identified and compared, fiber color is considered to be an excellent source of variation, and thus was examined in this study. Twelve dyes were employed, some being visually indistinguishable. Several different analyses and comparisons were done, including an inter-laboratory comparison and external validations. Lastly, common plastic samples and other polymers were analyzed using pyrolysis-gas chromatography/mass spectrometry, and their pyrolysis products were then analyzed using multivariate statistics. The classification accuracy varied dependent upon the number of classes chosen, but the plastics were grouped based on composition. The polymers were used as an external validation and misclassifications occurred with chlorinated samples all being placed into the category containing PVC.

  17. A comparison of radiological risk assessment methods for environmental restoration

    International Nuclear Information System (INIS)

    Dunning, D.E. Jr.; Peterson, J.M.

    1993-01-01

    Evaluation of risks to human health from exposure to ionizing radiation at radioactively contaminated sites is an integral part of the decision-making process for determining the need for remediation and selecting remedial actions that may be required. At sites regulated under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), a target risk range of 10 -4 to 10 -6 incremental cancer incidence over a lifetime is specified by the US Environmental Protection Agency (EPA) as generally acceptable, based on the reasonable maximum exposure to any individual under current and future land use scenarios. Two primary methods currently being used in conducting radiological risk assessments at CERCLA sites are compared in this analysis. Under the first method, the radiation dose equivalent (i.e., Sv or rem) to the receptors of interest over the appropriate period of exposure is estimated and multiplied by a risk factor (cancer risk/Sv). Alternatively, incremental cancer risk can be estimated by combining the EPA's cancer slope factors (previously termed potency factors) for radionuclides with estimates of radionuclide intake by ingestion and inhalation, as well as radionuclide concentrations in soil that contribute to external dose. The comparison of the two methods has demonstrated that resulting estimates of lifetime incremental cancer risk under these different methods may differ significantly, even when all other exposure assumptions are held constant, with the magnitude of the discrepancy depending upon the dominant radionuclides and exposure pathways for the site. The basis for these discrepancies, the advantages and disadvantages of each method, and the significance of the discrepant results for environmental restoration decisions are presented

  18. Comparison of methods for estimating carbon in harvested wood products

    International Nuclear Information System (INIS)

    Claudia Dias, Ana; Louro, Margarida; Arroja, Luis; Capela, Isabel

    2009-01-01

    There is a great diversity of methods for estimating carbon storage in harvested wood products (HWP) and, therefore, it is extremely important to agree internationally on the methods to be used in national greenhouse gas inventories. This study compares three methods for estimating carbon accumulation in HWP: the method suggested by Winjum et al. (Winjum method), the tier 2 method proposed by the IPCC Good Practice Guidance for Land Use, Land-Use Change and Forestry (GPG LULUCF) (GPG tier 2 method) and a method consistent with GPG LULUCF tier 3 methods (GPG tier 3 method). Carbon accumulation in HWP was estimated for Portugal under three accounting approaches: stock-change, production and atmospheric-flow. The uncertainty in the estimates was also evaluated using Monte Carlo simulation. The estimates of carbon accumulation in HWP obtained with the Winjum method differed substantially from the estimates obtained with the other methods, because this method tends to overestimate carbon accumulation with the stock-change and the production approaches and tends to underestimate carbon accumulation with the atmospheric-flow approach. The estimates of carbon accumulation provided by the GPG methods were similar, but the GPG tier 3 method reported the lowest uncertainties. For the GPG methods, the atmospheric-flow approach produced the largest estimates of carbon accumulation, followed by the production approach and the stock-change approach, by this order. A sensitivity analysis showed that using the ''best'' available data on production and trade of HWP produces larger estimates of carbon accumulation than using data from the Food and Agriculture Organization. (author)

  19. Comparison of test methods for mould growth in buildings

    DEFF Research Database (Denmark)

    Bonderup, Sirid; Gunnarsen, Lars Bo; Knudsen, Sofie Marie

    2016-01-01

    renovation needs. This is of importance when hidden surface testing would require destructive measures and subsequent renovation. After identifying available methods on the Danish market for assessing mould growth in dwellings, a case study was conducted to test the usefulness of the methods in four......The purpose of this work is to compare a range of test methods and kits for assessing whether a building structure is infested by mould fungi. A further purpose of this work is to evaluate whether air-based methods for sampling fungal emissions provide information qualifying decisions concerning...... methods measure different aspects relating to mould growth and vary in selectivity and precision. The two types of air samples indicated low levels of mould growth, even where the results of the other methods indicated high to moderate growth. With methods based on culture and DNA testing some differences...

  20. Comparison of RNA extraction methods in Thai aromatic coconut water

    Directory of Open Access Journals (Sweden)

    Nopporn Jaroonchon

    2015-10-01

    Full Text Available Many researches have reported that nucleic acid in coconut water is in free form and at very low yields which makes it difficult to process in molecular studies. Our research attempted to compare two extraction methods to obtain a higher yield of total RNA in aromatic coconut water and monitor its change at various fruit stages. The first method used ethanol and sodium acetate as reagents; the second method used lithium chloride. We found that extraction using only lithium chloride gave a higher total RNA yield than the method using ethanol to precipitate nucleic acid. In addition, the total RNA from both methods could be used in amplification of betaine aldehyde dehydrogenase2 (Badh2 genes, which is involved in coconut aroma biosynthesis, and could be used to perform further study as we expected. From the molecular study, the nucleic acid found in coconut water increased with fruit age.

  1. Comparison of Methods of Teaching Children Proper Lifting ...

    African Journals Online (AJOL)

    Objective: This study was designed to determine the effects of three teaching methods on children\\'s ability to demonstrate and recall their mastery of proper lifting techniques. Method: Ninety-three primary five and six public school children who had no knowledge of proper lifting technique were assigned into three equal ...

  2. Comparison between different synchronization methods of identical chaotic systems

    International Nuclear Information System (INIS)

    Haeri, Mohammad; Khademian, Behzad

    2006-01-01

    This paper studies and compares three nonadaptive (bidirectional, unidirectional, and sliding mode) and two adaptive (active control and backstepping) synchronization methods on the synchronizing of four pairs of identical chaotic systems (Chua's circuit, Roessler system, Lorenz system, and Lue system). Results from computer simulations are presented in order to illustrate the effectiveness of the methods and to compare them based on different criteria

  3. Comparison of methods to identify crop productivity constraints in developing countries. A review

    NARCIS (Netherlands)

    Kraaijvanger, R.G.M.; Sonneveld, M.P.W.; Almekinders, C.J.M.; Veldkamp, T.

    2015-01-01

    Selecting a method for identifying actual crop productivity constraints is an important step for triggering innovation processes. Applied methods can be diverse and although such methods have consequences for the design of intervention strategies, documented comparisons between various methods are

  4. Comparison of measurement methods for benzene and toluene

    Science.gov (United States)

    Wideqvist, U.; Vesely, V.; Johansson, C.; Potter, A.; Brorström-Lundén, E.; Sjöberg, K.; Jonsson, T.

    Diffusive sampling and active (pumped) sampling (tubes filled with Tenax TA or Carbopack B) were compared with an automatic BTX instrument (Chrompack, GC/FID) for measurements of benzene and toluene. The measurements were made during differing pollution levels and different weather conditions at a roof-top site and in a densely trafficked street canyon in Stockholm, Sweden. The BTX instrument was used as the reference method for comparison with the other methods. Considering all data the Perkin-Elmer diffusive samplers, containing Tenax TA and assuming a constant uptake rate of 0.406 cm3 min-1, showed about 30% higher benzene values compared to the BTX instrument. This discrepancy may be explained by a dose-dependent uptake rate with higher uptake rates at lower dose as suggested by laboratory experiments presented in the literature. After correction by applying the relationship between uptake rate and dose as suggested by Roche et al. (Atmos. Environ. 33 (1999) 1905), the two methods agreed almost perfectly. For toluene there was much better agreement between the two methods. No sign of a dose-dependent uptake could be seen. The mean concentrations and 95% confidence intervals of all toluene measurements (67 values) were (10.80±1.6) μg m -3 for diffusive sampling and (11.3±1.6) μg m -3 for the BTX instrument, respectively. The overall ratio between the concentrations obtained using diffusive sampling and the BTX instrument was 0.91±0.07 (95% confidence interval). Tenax TA was found to be equal to Carbopack B for measuring benzene and toluene in this concentration range, although it has been proposed not to be optimal for benzene. There was also good agreement between the active samplers and the BTX instrument.

  5. How Many Alternatives Can Be Ranked? A Comparison of the Paired Comparison and Ranking Methods.

    Science.gov (United States)

    Ock, Minsu; Yi, Nari; Ahn, Jeonghoon; Jo, Min-Woo

    2016-01-01

    To determine the feasibility of converting ranking data into paired comparison (PC) data and suggest the number of alternatives that can be ranked by comparing a PC and a ranking method. Using a total of 222 health states, a household survey was conducted in a sample of 300 individuals from the general population. Each respondent performed a PC 15 times and a ranking method 6 times (two attempts of ranking three, four, and five health states, respectively). The health states of the PC and the ranking method were constructed to overlap each other. We converted the ranked data into PC data and examined the consistency of the response rate. Applying probit regression, we obtained the predicted probability of each method. Pearson correlation coefficients were determined between the predicted probabilities of those methods. The mean absolute error was also assessed between the observed and the predicted values. The overall consistency of the response rate was 82.8%. The Pearson correlation coefficients were 0.789, 0.852, and 0.893 for ranking three, four, and five health states, respectively. The lowest mean absolute error was 0.082 (95% confidence interval [CI] 0.074-0.090) in ranking five health states, followed by 0.123 (95% CI 0.111-0.135) in ranking four health states and 0.126 (95% CI 0.113-0.138) in ranking three health states. After empirically examining the consistency of the response rate between a PC and a ranking method, we suggest that using five alternatives in the ranking method may be superior to using three or four alternatives. Copyright © 2016 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  6. German precursor study: methods and results

    International Nuclear Information System (INIS)

    Hoertner, H.; Frey, W.; von Linden, J.; Reichart, G.

    1985-01-01

    This study has been prepared by the GRS by contract of the Federal Minister of Interior. The purpose of the study is to show how the application of system-analytic tools and especially of probabilistic methods on the Licensee Event Reports (LERs) and on other operating experience can support a deeper understanding of the safety-related importance of the events reported in reactor operation, the identification of possible weak points, and further conclusions to be drawn from the events. Additionally, the study aimed at a comparison of its results for the severe core damage frequency with those of the German Risk Study as far as this is possible and useful. The German Precursor Study is a plant-specific study. The reference plant is Biblis NPP with its very similar Units A and B, whereby the latter was also the reference plant for the German Risk Study

  7. Benchmark Comparison of Cloud Analytics Methods Applied to Earth Observations

    Science.gov (United States)

    Lynnes, Chris; Little, Mike; Huang, Thomas; Jacob, Joseph; Yang, Phil; Kuo, Kwo-Sen

    2016-01-01

    Cloud computing has the potential to bring high performance computing capabilities to the average science researcher. However, in order to take full advantage of cloud capabilities, the science data used in the analysis must often be reorganized. This typically involves sharding the data across multiple nodes to enable relatively fine-grained parallelism. This can be either via cloud-based file systems or cloud-enabled databases such as Cassandra, Rasdaman or SciDB. Since storing an extra copy of data leads to increased cost and data management complexity, NASA is interested in determining the benefits and costs of various cloud analytics methods for real Earth Observation cases. Accordingly, NASA's Earth Science Technology Office and Earth Science Data and Information Systems project have teamed with cloud analytics practitioners to run a benchmark comparison on cloud analytics methods using the same input data and analysis algorithms. We have particularly looked at analysis algorithms that work over long time series, because these are particularly intractable for many Earth Observation datasets which typically store data with one or just a few time steps per file. This post will present side-by-side cost and performance results for several common Earth observation analysis operations.

  8. Benchmark Comparison of Cloud Analytics Methods Applied to Earth Observations

    Science.gov (United States)

    Lynnes, C.; Little, M. M.; Huang, T.; Jacob, J. C.; Yang, C. P.; Kuo, K. S.

    2016-12-01

    Cloud computing has the potential to bring high performance computing capabilities to the average science researcher. However, in order to take full advantage of cloud capabilities, the science data used in the analysis must often be reorganized. This typically involves sharding the data across multiple nodes to enable relatively fine-grained parallelism. This can be either via cloud-based filesystems or cloud-enabled databases such as Cassandra, Rasdaman or SciDB. Since storing an extra copy of data leads to increased cost and data management complexity, NASA is interested in determining the benefits and costs of various cloud analytics methods for real Earth Observation cases. Accordingly, NASA's Earth Science Technology Office and Earth Science Data and Information Systems project have teamed with cloud analytics practitioners to run a benchmark comparison on cloud analytics methods using the same input data and analysis algorithms. We have particularly looked at analysis algorithms that work over long time series, because these are particularly intractable for many Earth Observation datasets which typically store data with one or just a few time steps per file. This post will present side-by-side cost and performance results for several common Earth observation analysis operations.

  9. Comparison of Pectin Hydrogel Collection Methods in Microfluidic Device

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chaeyeon; Park, Ki-Su; Kang, Sung-Min; Kim, Jongmin; Song, YoungShin; Lee, Chang-Soo [Chungnam National University, Daejeon (Korea, Republic of)

    2015-12-15

    This study investigated the effect of different collection methods on physical properties of pectin hydrogels in microfluidic synthetic approach. The pectin hydrogels were simply produced by the incorporation of calcium ions dissolved in continuous mineral oil. Then, different collection methods, pipetting, tubing, and settling, for harvesting pectin hydrogels were applied. The settling method showed most uniform and monodispersed hydrogels. In the case of settling, a coefficient of variation was 3.46 which was lower than pipetting method (18.60) and tubing method (14.76). Under the settling method, we could control the size of hydrogels, ranging from 30 μm to 180 μm, by simple manipulation of the viscosity of pectin and volumetric flow rate of dispersed and continuous phase. Finally, according to the characteristics of simple encapsulation of biological materials, we envision that the pectin hydrogels can be applied to drug delivery, food, and biocompatible materials.

  10. Multiple comparisons in drug efficacy studies: scientific or marketing principles?

    Science.gov (United States)

    Leo, Jonathan

    2004-01-01

    When researchers design an experiment to compare a given medication to another medication, a behavioral therapy, or a placebo, the experiment often involves numerous comparisons. For instance, there may be several different evaluation methods, raters, and time points. Although scientifically justified, such comparisons can be abused in the interests of drug marketing. This article provides two recent examples of such questionable practices. The first involves the case of the arthritis drug celecoxib (Celebrex), where the study lasted 12 months but the authors only presented 6 months of data. The second case involves the NIMH Multimodal Treatment Study (MTA) study evaluating the efficacy of stimulant medication for attention-deficit hyperactivity disorder where ratings made by several groups are reported in contradictory fashion. The MTA authors have not clarified the confusion, at least in print, suggesting that the actual findings of the study may have played little role in the authors' reported conclusions.

  11. The Comparison between Teacher Centered and Student Centered Educational Methods

    Directory of Open Access Journals (Sweden)

    M Anvar

    2009-02-01

    Full Text Available Background and Purpose: Various approaches to learning are suggested & practiced. The traditional medical education were more teacher centered oriented . In this method the students’ involvement in the process of learning is not remarkable, but the new approach to medical education supports the students involvement. This study evaluated the various method of lecturing considering students involvements.Methods: One hundred two first year medical and nursing students involved in this study and their opinion about these two methods of learning were obtained by filling of a questionnaire. The subject of the lectures was “general psychology” which was carried out 50% by the students and 50% by the teacher. The statistical analysis was carried out by SPSS program.Results: Considering students opinion in student-centered method the various aspect of learning such as mutual understanding, use of textbooks and references were significantly increased , whereasother aspects of learning such as self esteem, study time, innovation, and study attitude though were improved, but were not significant as compared with teacher centered method. In teacher-centeredmethod the understanding of the subjects was significantly increased .Other aspects of learning such as motivation and concentration were improved but not significantly as compared with studentcentered method.Conclusion: As the result showed student centered method was favored in several aspects of learning while in teacher centered method only understanding of the subject was better . Careful choice of teaching method to provide a comprehensive learning experience should take into account these differences.Key words: TEACHER CENTERED, STUDENT CENTERED, LEARNING

  12. Comparación de cinco métodos para estimar la prevalencia de diabetes mellitus en estudios de base poblacional Comparison of five methods for estimating the prevalence of diabetes mellitus in population-based studies

    Directory of Open Access Journals (Sweden)

    Nicanor R. S. Pinto

    1997-10-01

    detectar los casos de diabetes mellitus previamente diagnosticados y se recomienda su uso para evaluaciones o planeamiento de servicios de salud. La medición de glucemia en ayunas (M3 como método exclusivo no reportó ventajas sobre el cuestionario individual (M2. Entre los métodos combinados o múltiples, la glucemia en ayunas junto con el cuestionario individual (M4 fue eficiente en relación con M5, que incorpora la glucemia a las 2 horas después de la ingestión de una sobrecarga oral de glucosa.To aid in the search for more practical and reliable methods for use in population-based studies of diabetes mellitus, this article compares five ways of estimating prevalence rates. The analysis was performed on secondary data from a cross-sectional study of a cluster sample of the adult population in nine state capitals in Brazil. The original study was carried out from 1986 to 1988. The 21 846 participants were classified as diabetic or not diabetic by five different methods: household questionnaires administered to the entire sample population (M1; individual questionnaires administered to the selected population (M2; measurement of fasting glucose levels in capillary blood, with levels > or = 120 mg/dL as the cutoff (M3; individual questionnaire and fasting capillary blood glucose > or = 120 mg/dL (M4; and individual questionnaire plus fasting capillary blood glucose > or = 200 mg/dL and capillary glucose 2 hours after oral glucose loading > or = 200 mg/dL (M5. Agreement between the methods was determined by comparison of the rates obtained and use of the kappa coefficient. The age-adjusted prevalence rates of diabetes varied according to the method used. Values obtained with M1 were lower than those indicated by M2; M3 values were higher than M2 values, except in the age group 60-69 years; and with M5 the rates were higher than with M4, except among persons 30-39 years old. With regard to the age-adjusted rates found by the various methods, M1 detected 84% of the M2

  13. Comparison of different methods for estimation of potential evapotranspiration

    International Nuclear Information System (INIS)

    Nazeer, M.

    2010-01-01

    Evapotranspiration can be estimated with different available methods. The aim of this research study to compare and evaluate the originally measured potential evapotranspiration from Class A pan with the Hargreaves equation, the Penman equation, the Penman-Montheith equation, and the FAO56 Penman-Monteith equation. The evaporation rate from pan recorded greater than stated methods. For each evapotranspiration method, results were compared against mean monthly potential evapotranspiration (PET) from Pan data according to FAO (ET/sub o/=K/sub pan X E/sub pan)), from daily measured recorded data of the twenty-five years (1984-2008). On the basis of statistical analysis between the pan data and the FAO56- Penman-Monteith method are not considered to be very significant (=0.98) at 95% confidence and prediction intervals. All methods required accurate weather data for precise results, for the purpose of this study the past twenty five years data were analyzed and used including maximum and minimum air temperature, relative humidity, wind speed, sunshine duration and rainfall. Based on linear regression analysis results the FAO56 PMM ranked first (R/sup 2/=0.98) followed by Hergreaves method (R/sup 2/=0.96), Penman-Monteith method (R/sup 2/=0.94) and Penman method (=0.93). Obviously, using FAO56 Penman Monteith method with precise climatic variables for ET/sub o/ estimation is more reliable than the other alternative methods, Hergreaves is more simple and rely only on air temperatures data and can be used alternative of FAO56 Penman-Monteith method if other climatic data are missing or unreliable. (author)

  14. Results of an interlaboratory comparison of analytical methods for contaminants of emerging concern in water.

    Science.gov (United States)

    Vanderford, Brett J; Drewes, Jörg E; Eaton, Andrew; Guo, Yingbo C; Haghani, Ali; Hoppe-Jones, Christiane; Schluesener, Michael P; Snyder, Shane A; Ternes, Thomas; Wood, Curtis J

    2014-01-07

    An evaluation of existing analytical methods used to measure contaminants of emerging concern (CECs) was performed through an interlaboratory comparison involving 25 research and commercial laboratories. In total, 52 methods were used in the single-blind study to determine method accuracy and comparability for 22 target compounds, including pharmaceuticals, personal care products, and steroid hormones, all at ng/L levels in surface and drinking water. Method biases ranged from caffeine, NP, OP, and triclosan had false positive rates >15%. In addition, some methods reported false positives for 17β-estradiol and 17α-ethynylestradiol in unspiked drinking water and deionized water, respectively, at levels higher than published predicted no-effect concentrations for these compounds in the environment. False negative rates were also generally contamination, misinterpretation of background interferences, and/or inappropriate setting of detection/quantification levels for analysis at low ng/L levels. The results of both comparisons were collectively assessed to identify parameters that resulted in the best overall method performance. Liquid chromatography-tandem mass spectrometry coupled with the calibration technique of isotope dilution were able to accurately quantify most compounds with an average bias of <10% for both matrixes. These findings suggest that this method of analysis is suitable at environmentally relevant levels for most of the compounds studied. This work underscores the need for robust, standardized analytical methods for CECs to improve data quality, increase comparability between studies, and help reduce false positive and false negative rates.

  15. Comparison of digestion methods to determine heavy metals in fertilizers

    Directory of Open Access Journals (Sweden)

    Ygor Jacques Agra Bezerra da Silva

    2014-04-01

    Full Text Available The lack of a standard method to regulate heavy metal determination in Brazilian fertilizers and the subsequent use of several digestion methods have produced variations in the results, hampering interpretation. Thus, the aim of this study was to compare the effectiveness of three digestion methods for determination of metals such as Cd, Ni, Pb, and Cr in fertilizers. Samples of 45 fertilizers marketed in northeastern Brazil were used. A fertilizer sample with heavy metal contents certified by the US National Institute of Standards and Technology (NIST was used as control. The following fertilizers were tested: rock phosphate; organo-mineral fertilizer with rock phosphate; single superphosphate; triple superphosphate; mixed N-P-K fertilizer; and fertilizer with micronutrients. The substances were digested according to the method recommended by the Ministry for Agriculture, Livestock and Supply of Brazil (MAPA and by the two methods 3051A and 3052 of the United States Environmental Protection Agency (USEPA. By the USEPA method 3052, higher portions of the less soluble metals such as Ni and Pb were recovered, indicating that the conventional digestion methods for fertilizers underestimate the total amount of these elements. The results of the USEPA method 3051A were very similar to those of the method currently used in Brazil (Brasil, 2006. The latter is preferable, in view of the lower cost requirement for acids, a shorter digestion period and greater reproducibility.

  16. Comparison of traditional physico-chemical methods and molecular ...

    African Journals Online (AJOL)

    This study was aim to review the efficiency of molecular markers and traditional physico-chemical methods for the identification of basmati rice. The study involved 44 promising varieties of Indica rices collected from geographically distant places and adapted to irrigated and aerobic agro-ecosystems. Quality data for ...

  17. A Comparison of Assessment Methods and Raters in Product Creativity

    Science.gov (United States)

    Lu, Chia-Chen; Luh, Ding-Bang

    2012-01-01

    Although previous studies have attempted to use different experiences of raters to rate product creativity by adopting the Consensus Assessment Method (CAT) approach, the validity of replacing CAT with another measurement tool has not been adequately tested. This study aimed to compare raters with different levels of experience (expert ves.…

  18. Computation Method Comparison for Th Based Seed-Blanket Cores

    International Nuclear Information System (INIS)

    Kolesnikov, S.; Galperin, A.; Shwageraus, E.

    2004-01-01

    This work compares two methods for calculating a given nuclear fuel cycle in the WASB configuration. Both methods use the ELCOS Code System (2-D transport code BOXER and 3-D nodal code SILWER) [4] are compared. In the first method, the cross-sections of the Seed and Blanket, needed for the 3-D nodal code are generated separately for each region by the 2-D transport code. In the second method, the cross-sections of the Seed and Blanket, needed for the 3-D nodal code are generated from Seed-Blanket Colorsets (Fig.1) calculated by the 2-D transport code. The evaluation of the error introduced by the first method is the main objective of the present study

  19. QUALITATIVE METHODS IN CREATIVITY STUDIES

    DEFF Research Database (Denmark)

    Hertel, Frederik

    2015-01-01

    In this article we will focus on developing a qualitative research design suitable for conducting case study in creativity. The case is a team of workers (See Hertel, 2015) doing industrial cleaning in the Danish food industry. The hypothesis is that these workers are both participating in......-specific methods, involving a discussion of creativity test, divergent and convergent thinking, for studying creativity in this specific setting. Beside from that we will develop a research design involving a combination of methods necessary for conducting a case study in the setting mentioned....

  20. Comparison of Different Drying Methods for Recovery of Mushroom DNA.

    Science.gov (United States)

    Wang, Shouxian; Liu, Yu; Xu, Jianping

    2017-06-07

    Several methods have been reported for drying mushroom specimens for population genetic, taxonomic, and phylogenetic studies. However, most methods have not been directly compared for their effectiveness in preserving mushroom DNA. In this study, we compared silica gel drying at ambient temperature and oven drying at seven different temperatures. Two mushroom species representing two types of fruiting bodies were examined: the fleshy button mushroom Agaricus bisporus and the leathery shelf fungus Trametes versicolor. For each species dried with the eight methods, we assessed the mushroom water loss rate, the quality and quantity of extracted DNA, and the effectiveness of using the extracted DNA as a template for PCR amplification of two DNA fragments (ITS and a single copy gene). Dried specimens from all tested methods yielded sufficient DNA for PCR amplification of the two genes in both species. However, differences among the methods for the two species were found in: (i) the time required by different drying methods for the fresh mushroom tissue to reach a stable weight; and (ii) the relative quality and quantity of the extracted genomic DNA. Among these methods, oven drying at 70 °C for 3-4 h seemed the most efficient for preserving field mushroom samples for subsequent molecular work.

  1. Comparison between different synchronization methods of identical chaotic systems

    Energy Technology Data Exchange (ETDEWEB)

    Haeri, Mohammad [Advanced Control System Laboratory, Electrical Engineering Department, Sharif University of Technology, Azadi Avenue, P.O. Box 11365-9363 Tehran (Iran, Islamic Republic of)]. E-mail: haeri@sina.sharif.edu; Khademian, Behzad [Advanced Control System Laboratory, Electrical Engineering Department, Sharif University of Technology, Azadi Avenue, P.O. Box 11365-9363 Tehran (Iran, Islamic Republic of)

    2006-08-15

    This paper studies and compares three nonadaptive (bidirectional, unidirectional, and sliding mode) and two adaptive (active control and backstepping) synchronization methods on the synchronizing of four pairs of identical chaotic systems (Chua's circuit, Roessler system, Lorenz system, and Lue system). Results from computer simulations are presented in order to illustrate the effectiveness of the methods and to compare them based on different criteria.

  2. Development of a practical image-based scatter correction method for brain perfusion SPECT: comparison with the TEW method

    International Nuclear Information System (INIS)

    Shidahara, Miho; Kato, Takashi; Kawatsu, Shoji; Yoshimura, Kumiko; Ito, Kengo; Watabe, Hiroshi; Kim, Kyeong Min; Iida, Hidehiro; Kato, Rikio

    2005-01-01

    An image-based scatter correction (IBSC) method was developed to convert scatter-uncorrected into scatter-corrected SPECT images. The purpose of this study was to validate this method by means of phantom simulations and human studies with 99m Tc-labeled tracers, based on comparison with the conventional triple energy window (TEW) method. The IBSC method corrects scatter on the reconstructed image I AC μb with Chang's attenuation correction factor. The scatter component image is estimated by convolving I AC μb with a scatter function followed by multiplication with an image-based scatter fraction function. The IBSC method was evaluated with Monte Carlo simulations and 99m Tc-ethyl cysteinate dimer SPECT human brain perfusion studies obtained from five volunteers. The image counts and contrast of the scatter-corrected images obtained by the IBSC and TEW methods were compared. Using data obtained from the simulations, the image counts and contrast of the scatter-corrected images obtained by the IBSC and TEW methods were found to be nearly identical for both gray and white matter. In human brain images, no significant differences in image contrast were observed between the IBSC and TEW methods. The IBSC method is a simple scatter correction technique feasible for use in clinical routine. (orig.)

  3. Development of a practical image-based scatter correction method for brain perfusion SPECT: comparison with the TEW method

    Energy Technology Data Exchange (ETDEWEB)

    Shidahara, Miho; Kato, Takashi; Kawatsu, Shoji; Yoshimura, Kumiko; Ito, Kengo [National Center for Geriatrics and Gerontology Research Institute, Department of Brain Science and Molecular Imaging, Obu, Aichi (Japan); Watabe, Hiroshi; Kim, Kyeong Min; Iida, Hidehiro [National Cardiovascular Center Research Institute, Department of Investigative Radiology, Suita (Japan); Kato, Rikio [National Center for Geriatrics and Gerontology, Department of Radiology, Obu (Japan)

    2005-10-01

    An image-based scatter correction (IBSC) method was developed to convert scatter-uncorrected into scatter-corrected SPECT images. The purpose of this study was to validate this method by means of phantom simulations and human studies with {sup 99m}Tc-labeled tracers, based on comparison with the conventional triple energy window (TEW) method. The IBSC method corrects scatter on the reconstructed image I{sub AC}{sup {mu}}{sup b} with Chang's attenuation correction factor. The scatter component image is estimated by convolving I{sub AC}{sup {mu}}{sup b} with a scatter function followed by multiplication with an image-based scatter fraction function. The IBSC method was evaluated with Monte Carlo simulations and {sup 99m}Tc-ethyl cysteinate dimer SPECT human brain perfusion studies obtained from five volunteers. The image counts and contrast of the scatter-corrected images obtained by the IBSC and TEW methods were compared. Using data obtained from the simulations, the image counts and contrast of the scatter-corrected images obtained by the IBSC and TEW methods were found to be nearly identical for both gray and white matter. In human brain images, no significant differences in image contrast were observed between the IBSC and TEW methods. The IBSC method is a simple scatter correction technique feasible for use in clinical routine. (orig.)

  4. Development of a practical image-based scatter correction method for brain perfusion SPECT: comparison with the TEW method.

    Science.gov (United States)

    Shidahara, Miho; Watabe, Hiroshi; Kim, Kyeong Min; Kato, Takashi; Kawatsu, Shoji; Kato, Rikio; Yoshimura, Kumiko; Iida, Hidehiro; Ito, Kengo

    2005-10-01

    An image-based scatter correction (IBSC) method was developed to convert scatter-uncorrected into scatter-corrected SPECT images. The purpose of this study was to validate this method by means of phantom simulations and human studies with 99mTc-labeled tracers, based on comparison with the conventional triple energy window (TEW) method. The IBSC method corrects scatter on the reconstructed image I(mub)AC with Chang's attenuation correction factor. The scatter component image is estimated by convolving I(mub)AC with a scatter function followed by multiplication with an image-based scatter fraction function. The IBSC method was evaluated with Monte Carlo simulations and 99mTc-ethyl cysteinate dimer SPECT human brain perfusion studies obtained from five volunteers. The image counts and contrast of the scatter-corrected images obtained by the IBSC and TEW methods were compared. Using data obtained from the simulations, the image counts and contrast of the scatter-corrected images obtained by the IBSC and TEW methods were found to be nearly identical for both gray and white matter. In human brain images, no significant differences in image contrast were observed between the IBSC and TEW methods. The IBSC method is a simple scatter correction technique feasible for use in clinical routine.

  5. A comparison of analysis methods to estimate contingency strength.

    Science.gov (United States)

    Lloyd, Blair P; Staubitz, Johanna L; Tapp, Jon T

    2018-05-09

    To date, several data analysis methods have been used to estimate contingency strength, yet few studies have compared these methods directly. To compare the relative precision and sensitivity of four analysis methods (i.e., exhaustive event-based, nonexhaustive event-based, concurrent interval, concurrent+lag interval), we applied all methods to a simulated data set in which several response-dependent and response-independent schedules of reinforcement were programmed. We evaluated the degree to which contingency strength estimates produced from each method (a) corresponded with expected values for response-dependent schedules and (b) showed sensitivity to parametric manipulations of response-independent reinforcement. Results indicated both event-based methods produced contingency strength estimates that aligned with expected values for response-dependent schedules, but differed in sensitivity to response-independent reinforcement. The precision of interval-based methods varied by analysis method (concurrent vs. concurrent+lag) and schedule type (continuous vs. partial), and showed similar sensitivities to response-independent reinforcement. Recommendations and considerations for measuring contingencies are identified. © 2018 Society for the Experimental Analysis of Behavior.

  6. COMPARISON OF DETERMINING METHODS REGARDING SELENIUM CONTENT IN WHEAT PLANT

    Directory of Open Access Journals (Sweden)

    Mihaela Monica Stanciu-Burileanu

    2010-01-01

    Full Text Available As a metallic chemical element, selenium has received special attention from biologists because of its dual role as a trace element essential and toxic. The important part of enzymes that protect cells against the effects of free radicals that are produced during normal metabolism of oxygen. Also, selenium is essential for normal immune system and thyroid gland, The concentration of selenium in the soil, which varies by region, determines the default concentration of selenium in plants growing in the soil.The purpose of this paper is to present methods of comparison, dry oxidation at 450ºC and wet digestion – digestion with acids in high concentrations at microwave system digestion, for determining selenium content from wheat samples collected from the south-eastern part of Romania, namely Bărăgan Plain and Central-South Dobrogea. Selenium separation and dosage from obtained extracts carry out through a selective hydride generation atomic absorption spectrophotometry. With the software SURFER, a tendency map of selenium distribution was drawn.

  7. A comparison of methods in estimating soil water erosion

    Directory of Open Access Journals (Sweden)

    Marisela Pando Moreno

    2012-02-01

    Full Text Available A comparison between direct field measurements and predictions of soil water erosion using two variant; (FAO and R/2 index of the Revised Universal Soil Loss Equation (RUSLE was carried out in a microcatchment o 22.32 km2 in Northeastern Mexico. Direct field measurements were based on a geomorphologic classification of the area; while environmental units were defined for applying the equation. Environmental units were later grouped withir geomorphologic units to compare results. For the basin as a whole, erosion rates from FAO index were statistical!; equal to those measured on the field, while values obtained from the R/2 index were statistically different from the res and overestimated erosion. However, when comparing among geomorphologic units, erosion appeared overestimate! in steep units and underestimated in more flat areas. The most remarkable differences on erosion rates, between th( direct and FAO methods, were for those units where gullies have developed, fn these cases, erosion was underestimated by FAO index. Hence, it is suggested that a weighted factor for presence of gullies should be developed and included in RUSLE equation.

  8. Comparison of classification algorithms for various methods of preprocessing radar images of the MSTAR base

    Science.gov (United States)

    Borodinov, A. A.; Myasnikov, V. V.

    2018-04-01

    The present work is devoted to comparing the accuracy of the known qualification algorithms in the task of recognizing local objects on radar images for various image preprocessing methods. Preprocessing involves speckle noise filtering and normalization of the object orientation in the image by the method of image moments and by a method based on the Hough transform. In comparison, the following classification algorithms are used: Decision tree; Support vector machine, AdaBoost, Random forest. The principal component analysis is used to reduce the dimension. The research is carried out on the objects from the base of radar images MSTAR. The paper presents the results of the conducted studies.

  9. A comparison of methods for teaching receptive language to toddlers with autism.

    Science.gov (United States)

    Vedora, Joseph; Grandelski, Katrina

    2015-01-01

    The use of a simple-conditional discrimination training procedure, in which stimuli are initially taught in isolation with no other comparison stimuli, is common in early intensive behavioral intervention programs. Researchers have suggested that this procedure may encourage the development of faulty stimulus control during training. The current study replicated previous work that compared the simple-conditional and the conditional-only methods to teach receptive labeling of pictures to young children with autism spectrum disorder. Both methods were effective, but the conditional-only method required fewer sessions to mastery. © Society for the Experimental Analysis of Behavior.

  10. Structured Feedback Training for Time-Out: Efficacy and Efficiency in Comparison to a Didactic Method.

    Science.gov (United States)

    Jensen, Scott A; Blumberg, Sean; Browning, Megan

    2017-09-01

    Although time-out has been demonstrated to be effective across multiple settings, little research exists on effective methods for training others to implement time-out. The present set of studies is an exploratory analysis of a structured feedback method for training time-out using repeated role-plays. The three studies examined (a) a between-subjects comparison to more a traditional didactic/video modeling method of time-out training, (b) a within-subjects comparison to traditional didactic/video modeling training for another skill, and (c) the impact of structured feedback training on in-home time-out implementation. Though findings are only preliminary and more research is needed, the structured feedback method appears across studies to be an efficient, effective method that demonstrates good maintenance of skill up to 3 months post training. Findings suggest, though do not confirm, a benefit of the structured feedback method over a more traditional didactic/video training model. Implications and further research on the method are discussed.

  11. Pyrrolizidine alkaloids in honey: comparison of analytical methods.

    Science.gov (United States)

    Kempf, M; Wittig, M; Reinhard, A; von der Ohe, K; Blacquière, T; Raezke, K-P; Michel, R; Schreier, P; Beuerle, T

    2011-03-01

    ragwort pollen were detected (0-6.3%), in some cases extremely high PA values were detected (n = 31; ranging from 0 to 13019 µg kg(-1), average = 1261 or 76 µg kg(-1) for GC-MS and LC-MS, respectively). Here the results showed significantly different quantification results. The GC-MS sum parameter showed in average higher values (on average differing by a factor 17). The main reason for the discrepancy is most likely the incomplete coverage of the J. vulgaris PA pattern. Major J. vulgaris PAs like jacobine-type PAs or erucifoline/acetylerucifoline were not available as reference compounds for the LC-MS target approach. Based on the direct comparison, both methods are considered from various perspectives and the respective individual strengths and weaknesses for each method are presented in detail.

  12. Comparison of two split-window methods for retrieving land surface temperature from MODIS data

    Science.gov (United States)

    Zhao, Shaohua; Qin, Qiming; Yang, Yonghui; Xiong, Yujiu; Qiu, Guoyu

    2009-08-01

    Land surface temperature (LST) is a key parameter in environment and earth science study, especially for monitoring drought. The objective of this work is a comparison of two split-window methods: Mao method and Sobrino method, for retrieving LST using MODIS (Moderate-resolution Imaging Spectroradiometer) data in North China Plain. The results show that the max, min and mean errors of Mao method are 1.33K, 1.54K and 0.13K lower than the standard LST product respectively; while those of Sobrino method are 0.73K, 1.46K and 1.50K higher than the standard respectively. Validation of the two methods using LST product based on weather stations shows a good agreement between the standard and Sobrino method, with RMSE of 1.17K, whereas RMSE of Mao method is 1.85K. Finally, the study introduces the Sobmao method, which is based on Sobrino method but simplifies the estimation of atmospheric water vapour content using Mao method. The Sobmao method has almost the same accuracy with Sobrino method. With high accuracy and simplification of water vapour content estimation, the Sobmao method is recommendable in LST inversion for good application in Ningxia region, the northwest China, with mean error of 0.33K and the RMSE value of 0.91K.

  13. Comparison of bone densitometry methods in healthy and osteoporotic women

    International Nuclear Information System (INIS)

    Reinbold, W.D.; Dinkel, E.; Genant, H.K.

    1988-01-01

    To compare methods of noninvasive measurement of bone mineral content, 40 healthy early postmenopausal women and 68 postmenopausal women with osteoporosis were studied. The methods included mono- and dual-energy quantitative computed tomography (QCT) and dual-photon absorptiometry (DPA) of the lumbar spine, single-photon absorptiometry (SPA) of the distal third of the radius, and combined cortical thickness (CCT) of the second metacarpal shaft. Lateral thoracolumbar radiographic studies were performed and the spinal fracture index calculated. There was good correlation between QCT and DPA methods in early postmenopausal women and moderate correlation in postmenopausal osteoporotic women. Correlations between spinal measurements (QCT or DPA) and appendicular cortical measurements (SPA or CCT) were moderate in healthy women and poor in osteoporotic women. Measurements resulting from one method were not predictive of measurements obtained by another method for individual patients. The strongest correlation with severity of vertebral fracture was provided by QCT and the weakest by SPA. There was good correlation between single- and dual-energy QCT results. Osteoporotic women and younger healthy women can be distinguished by the measurement of spinal trabecular bone density using QCT, and this method is more sensitive than the measurement of spinal integral bone by DPA or of appendicular cortical bone by SPA or CCT. (orig.) [de

  14. Comparison of the Methods for the Diagnosis of Onychomycosis

    Directory of Open Access Journals (Sweden)

    Banu Bayraktar

    2008-10-01

    Full Text Available Background and Design: A potassium hydroxide (KOH direct microscopic examination, histopathological investigation with periodic acid-Schiff (PAS stain and fungal culture are common diagnostic methods in the diagnosis of onychomycosis. The purpose of this study was to compare these three methods for the diagnosis of onychomycosis.Material and Method: A total of 100 patients who were suspected clinically of having onychomycosis on their toenails were included in this study. Three diagnostic tests were performed for each patients. In addition to clinical suspicion when one of the diagnostic tests was positive the diagnosis of onychomycosis was made. Accordingly, the sensitivity and the negative predictive value were calculated for each diagnostic test.Results: In 92 (92% of the patients, at least one of the three diagnostic methods was positive. The sensitivites of these methods were as follows: KOH direct microscopic examination, 92%; histopathological investigation with PAS stain, 80%; and culture, 20%. Their negative predictive values were also 53%, 42%, and 10% respectively. Conclusion: KOH direct microscopic examination is the most sensitive method for the diagnosis of onychomycosis. Its high negative predictive value supports this finding. (Turkderm 2008; 42: 91-3

  15. A comparison of confirmatory factor analysis methods : Oblique multiple group method versus confirmatory common factor method

    NARCIS (Netherlands)

    Stuive, Ilse

    2007-01-01

    Confirmatieve Factor Analyse (CFA) is een vaak gebruikte methode wanneer onderzoekers een bepaalde veronderstelling hebben over de indeling van items in één of meerdere subtests en willen onderzoeken of deze indeling ook wordt ondersteund door verzamelde onderzoeksgegevens. De meest gebruikte

  16. Liquid metal reactor/Pressurized water reactor plant comparison study

    International Nuclear Information System (INIS)

    Halverson, T.G.

    1986-01-01

    The selection between alternative electric power generating technologies is mainly based on their overall economics. Capital costs account for over 60% of the total busbar cost of nuclear plants. Estimates reported in the literature have shown capital cost ratios of LMRs to PWRs ranging from less than 1 to as high as 1.8. To reduce this range of uncertainty, the study selected a method for cataloging plant hardware and then performed comparisons using engineering judgment as to the anticipated and reasonable cost differences. The paper summarizes the resulting one-on-one comparisons of components, systems, and buildings and identifies the LMR-PWR similarities and differences which influence costs. The study leads to the conclusion that the capital cost of the most up-to-date large LMR design would be very close to that of the latest PWRs

  17. COMPARISON OF FOUR METHODS TO DETECT ADVERSE EVENTS IN HOSPITAL

    Directory of Open Access Journals (Sweden)

    Inge Dhamanti

    2015-09-01

    Full Text Available AbstrakDeteksi terjadinya kejadian yang tidak diharapkan (KTD telah menjadi salah satu tantangan dalam keselamatan pasien oleh karena itu metode untuk mendeteksi terjadinya KTD sangatlah penting untuk meningkatkan keselamatan pasien. Tujuan dari artikel ini adalah untuk membandingkan kelebihan dan kekurangan dari beberapa metode untuk mendeteksi terjadinya KTD di rumah sakit, meliputi review rekam medis, pelaporan insiden secara mandiri, teknologi informasi, dan pelaporan oleh pasien. Studi ini merupakan kajian literatur untuk membandingkan dan menganalisa metode terbaik untuk mendeteksi KTD yang dapat diimplementasikan oleh rumah sakit. Semua dari empat metode telah terbukti mampu untuk mendeteksi terjadinya KTD di rumah sakit, tetapi masing-masing metode mempunyai kelebihan dan kekurangan yang perlu diatasi. Tidak ada satu metode terbaik yang akan memberikan hasil terbaik untuk mendeteksi KTD di rumah sakit. Sehingga untuk mendeteksi lebih banyak KTD yang seharusnya dapat dicegah, atau KTD yang telah terjadi, rumah sakit seharusnya mengkombinasikan lebih dari satu metode untuk mendeteksi, karena masing-masing metode mempunyai sensitivitas berbeda-beda.AbstractDetecting adverse events has become one of the challenges in patient safety thus methods to detect adverse events become critical for improving patient safety. The purpose of this paper is to compare the strengths and weaknesses of several methods of identifying adverse events in hospital, including medical records reviews, self-reported incidents, information technology, and patient self-reports. This study is a literature review to compared and analyzed to determine the best method implemented by the hospital. All of four methods have been proved in their ability in detecting adverse events in hospitals, but each method had strengths and limitations to be overcome. There is no ‘best’ single method that will give the best results for adverse events detection in hospital. Thus to

  18. A comparison of multivariate genome-wide association methods

    DEFF Research Database (Denmark)

    Galesloot, Tessel E; Van Steen, Kristel; Kiemeney, Lambertus A L M

    2014-01-01

    Joint association analysis of multiple traits in a genome-wide association study (GWAS), i.e. a multivariate GWAS, offers several advantages over analyzing each trait in a separate GWAS. In this study we directly compared a number of multivariate GWAS methods using simulated data. We focused on six...... methods that are implemented in the software packages PLINK, SNPTEST, MultiPhen, BIMBAM, PCHAT and TATES, and also compared them to standard univariate GWAS, analysis of the first principal component of the traits, and meta-analysis of univariate results. We simulated data (N = 1000) for three...... for scenarios with an opposite sign of genetic and residual correlation. All multivariate analyses resulted in a higher power than univariate analyses, even when only one of the traits was associated with the QTL. Hence, use of multivariate GWAS methods can be recommended, even when genetic correlations between...

  19. Comparison results on preconditioned SOR-type iterative method for Z-matrices linear systems

    Science.gov (United States)

    Wang, Xue-Zhong; Huang, Ting-Zhu; Fu, Ying-Ding

    2007-09-01

    In this paper, we present some comparison theorems on preconditioned iterative method for solving Z-matrices linear systems, Comparison results show that the rate of convergence of the Gauss-Seidel-type method is faster than the rate of convergence of the SOR-type iterative method.

  20. An enquiry into the method of paired comparison: reliability, scaling, and Thurstone's Law of Comparative Judgment

    Science.gov (United States)

    Thomas C. Brown; George L. Peterson

    2009-01-01

    The method of paired comparisons is used to measure individuals' preference orderings of items presented to them as discrete binary choices. This paper reviews the theory and application of the paired comparison method, describes a new computer program available for eliciting the choices, and presents an analysis of methods for scaling paired choice data to...

  1. Comparisons and Analyses of Gifted Students' Characteristics and Learning Methods

    Science.gov (United States)

    Lu, Jiamei; Li, Daqi; Stevens, Carla; Ye, Renmin

    2017-01-01

    Using PISA 2009, an international education database, this study compares gifted and talented (GT) students in three groups with normal (non-GT) students by examining student characteristics, reading, schooling, learning methods, and use of strategies for understanding and memorizing. Results indicate that the GT and non-GT gender distributions…

  2. Comparison of protein extraction methods suitable for proteomics ...

    African Journals Online (AJOL)

    An efficient protein extraction method is a prerequisite for successful implementation of proteomics. In this study, seedling roots of Jerusalem artichoke were treated with the concentration of 250 mM NaCl for 36 h. Subsequently, six different protocols of protein extraction were applied to seedling roots of Jerusalem artichoke ...

  3. Blanket comparison and selection study. Volume I

    International Nuclear Information System (INIS)

    1983-10-01

    The objectives of the Blanket Comparison and Selection Study (BCSS) can be stated as follows: (1) Define a small number (approx. 3) of blanket design concepts that should be the focus of the blanket R and D program. A design concept is defined by the selection of all materials (e.g., breeder, coolant, structure and multiplier) and other major characteristics that significantly influence the R and D requirements. (2) Identify and prioritize the critical issues for the leading blanket concepts. (3) Provide the technical input necessary to develop a blanket R and D program plan. Guidelines for prioritizing the R and D requirements include: (a) critical feasibility issues for the leading blanket concepts will receive the highest priority, and (b) for equally important feasibility issues, higher R and D priority will be given to those that require minimum cost and short time

  4. The reflexive case study method

    DEFF Research Database (Denmark)

    Rittenhofer, Iris

    2015-01-01

    This paper extends the international business research on small to medium-sized enterprises (SME) at the nexus of globalization. Based on a conceptual synthesis across disciplines and theoretical perspectives, it offers management research a reflexive method for case study research of postnational...

  5. Simulated annealing method for electronic circuits design: adaptation and comparison with other optimization methods

    International Nuclear Information System (INIS)

    Berthiau, G.

    1995-10-01

    The circuit design problem consists in determining acceptable parameter values (resistors, capacitors, transistors geometries ...) which allow the circuit to meet various user given operational criteria (DC consumption, AC bandwidth, transient times ...). This task is equivalent to a multidimensional and/or multi objective optimization problem: n-variables functions have to be minimized in an hyper-rectangular domain ; equality constraints can be eventually specified. A similar problem consists in fitting component models. In this way, the optimization variables are the model parameters and one aims at minimizing a cost function built on the error between the model response and the data measured on the component. The chosen optimization method for this kind of problem is the simulated annealing method. This method, provided by the combinatorial optimization domain, has been adapted and compared with other global optimization methods for the continuous variables problems. An efficient strategy of variables discretization and a set of complementary stopping criteria have been proposed. The different parameters of the method have been adjusted with analytical functions of which minima are known, classically used in the literature. Our simulated annealing algorithm has been coupled with an open electrical simulator SPICE-PAC of which the modular structure allows the chaining of simulations required by the circuit optimization process. We proposed, for high-dimensional problems, a partitioning technique which ensures proportionality between CPU-time and variables number. To compare our method with others, we have adapted three other methods coming from combinatorial optimization domain - the threshold method, a genetic algorithm and the Tabu search method - The tests have been performed on the same set of test functions and the results allow a first comparison between these methods applied to continuous optimization variables. Finally, our simulated annealing program

  6. Investigation of Industrialised Building System Performance in Comparison to Conventional Construction Method

    Directory of Open Access Journals (Sweden)

    Othuman Mydin M.A.

    2014-03-01

    Full Text Available Conventional construction methods are still widely practised, although many researches have indicated that this method is less effective compared to the IBS construction method. The existence of the IBS has added to the many techniques within the construction industry. This study is aimed at making comparisons between the two construction approaches. Case studies were conducted at four sites in the state of Penang, Malaysia. Two projects were IBS-based while the remaining two deployed the conventional method of construction. Based on an analysis of the results, it can be concluded that the IBS approach has more to offer compared to the conventional method. Among these advantages are shorter construction periods, reduced overall costs, less labour needs, better site conditions and the production of higher quality components.

  7. Comparison of methods for separating vibration sources in rotating machinery

    Science.gov (United States)

    Klein, Renata

    2017-12-01

    Vibro-acoustic signatures are widely used for diagnostics of rotating machinery. Vibration based automatic diagnostics systems need to achieve a good separation between signals generated by different sources. The separation task may be challenging, since the effects of the different vibration sources often overlap. In particular, there is a need to separate between signals related to the natural frequencies of the structure and signals resulting from the rotating components (signal whitening), as well as a need to separate between signals generated by asynchronous components like bearings and signals generated by cyclo-stationary components like gears. Several methods were proposed to achieve the above separation tasks. The present study compares between some of these methods. The paper also presents a new method for whitening, Adaptive Clutter Separation, as well as a new efficient algorithm for dephase, which separates between asynchronous and cyclo-stationary signals. For whitening the study compares between liftering of the high quefrencies and adaptive clutter separation. For separating between the asynchronous and the cyclo-stationary signals the study compares between liftering in the quefrency domain and dephase. The methods are compared using both simulated signals and real data.

  8. Comparison of two solution ways of district heating control: Using analysis methods, using artificial intelligence methods

    Energy Technology Data Exchange (ETDEWEB)

    Balate, J.; Sysala, T. [Technical Univ., Zlin (Czech Republic). Dept. of Automation and Control Technology

    1997-12-31

    The District Heating Systems - DHS (Centralized Heat Supply Systems - CHSS) are being developed in large cities in accordance with their growth. The systems are formed by enlarging networks of heat distribution to consumers and at the same time they interconnect the heat sources gradually built. The heat is distributed to the consumers through the circular networks, that are supplied by several cooperating heat sources, that means by power and heating plants and heating plants. The complicated process of heat production technology and supply requires the system approach when solving the concept of automatized control. The paper deals with comparison of the solution way using the analysis methods and using the artificial intelligence methods. (orig.)

  9. Methacholine challenge test: Comparison of tidal breathing and dosimeter methods in children.

    Science.gov (United States)

    Mazi, Ahlam; Lands, Larry C; Zielinski, David

    2018-02-01

    Methacholine Challenge Test (MCT) is used to confirm, assess the severity and/or rule out asthma. Two MCT methods are described as equivalent by the American Thoracic Society (ATS), the tidal breathing and the dosimeter methods. However, the majority of adult studies suggest that individuals with asthma do not react at the same PC 20 between the two methods. Additionally, the nebulizers used are no longer available and studies suggest current nebulizers are not equivalent to these. Our study investigates the difference in positive MCT tests between three methods in a pediatric population. A retrospective, chart review of all MCT performed with spirometry at the Montreal Children's Hospital from January 2006 to March 2016. A comparison of the percentage positive MCT tests with three methods, tidal breathing, APS dosimeter and dose adjusted DA-dosimeter, was performed at different cutoff points up to 8 mg/mL. A total of 747 subjects performed the tidal breathing method, 920 subjects the APS dosimeter method, and 200 subjects the DA-dosimeter method. At a PC 20 cutoff ≤4 mg/mL, the percentage positive MCT was significantly higher using the tidal breathing method (76.3%) compared to the APS dosimeter (45.1%) and DA-dosimeter (65%) methods (P < 0.0001). The choice of nebulizer and technique significantly impacts the rate of positivity when using MCT to diagnose and assess asthma. Lack of direct comparison of techniques within the same individuals and clinical assessment should be addressed in future studies to standardize MCT methodology in children. © 2017 Wiley Periodicals, Inc.

  10. A Comparison of Various Forecasting Methods for Autocorrelated Time Series

    Directory of Open Access Journals (Sweden)

    Karin Kandananond

    2012-07-01

    Full Text Available The accuracy of forecasts significantly affects the overall performance of a whole supply chain system. Sometimes, the nature of consumer products might cause difficulties in forecasting for the future demands because of its complicated structure. In this study, two machine learning methods, artificial neural network (ANN and support vector machine (SVM, and a traditional approach, the autoregressive integrated moving average (ARIMA model, were utilized to predict the demand for consumer products. The training data used were the actual demand of six different products from a consumer product company in Thailand. Initially, each set of data was analysed using Ljung‐Box‐Q statistics to test for autocorrelation. Afterwards, each method was applied to different sets of data. The results indicated that the SVM method had a better forecast quality (in terms of MAPE than ANN and ARIMA in every category of products.

  11. Comparison of four surgical methods for eyebrow reconstruction

    Directory of Open Access Journals (Sweden)

    Omranifard Mahmood

    2007-01-01

    Full Text Available Background: The eyebrow plays an important role in facial harmony and eye protection. Eyebrows can be injured by burn, trauma, tumour, tattooing and alopecia. Eyebrow reconstructions have been done via several techniques. Here, our experience with a fairly new method for eyebrow reconstruction is presented. Materials and Methods: This is a descriptive-analytical study which was done on 76 patients at the Al-Zahra and Imam Mousa Kazem hospitals at Isfahan University of Medical University, Isfahan, Iran, from 1994 to 2004. Totally 86 eyebrows were reconstructed. All patients were examined before and after the operation. Methods which are commonly applied in eyebrow reconstruction are as follows: 1. Superficial Temporal Artery Flap (Island, 2. Interpolitation Scalp Flap, 3. Graft. Our method which is named Forehead Facial Island Flap with inferior pedicle provides an easier approach for the surgeon and more ideal hair growth direction for the patient. Results: Significantly lower rates of complication along with greater patient satisfaction were obtained with Forehead Facial Island Flap. Conclusions: According to the acquired results, this method seems to be more technically practical and aesthetically favourable when compared to others.

  12. Comparison of DNA preservation methods for environmental bacterial community samples.

    Science.gov (United States)

    Gray, Michael A; Pratte, Zoe A; Kellogg, Christina A

    2013-02-01

    Field collections of environmental samples, for example corals, for molecular microbial analyses present distinct challenges. The lack of laboratory facilities in remote locations is common, and preservation of microbial community DNA for later study is critical. A particular challenge is keeping samples frozen in transit. Five nucleic acid preservation methods that do not require cold storage were compared for effectiveness over time and ease of use. Mixed microbial communities of known composition were created and preserved by DNAgard(™), RNAlater(®), DMSO-EDTA-salt (DESS), FTA(®) cards, and FTA Elute(®) cards. Automated ribosomal intergenic spacer analysis and clone libraries were used to detect specific changes in the faux communities over weeks and months of storage. A previously known bias in FTA(®) cards that results in lower recovery of pure cultures of Gram-positive bacteria was also detected in mixed community samples. There appears to be a uniform bias across all five preservation methods against microorganisms with high G + C DNA. Overall, the liquid-based preservatives (DNAgard(™), RNAlater(®), and DESS) outperformed the card-based methods. No single liquid method clearly outperformed the others, leaving method choice to be based on experimental design, field facilities, shipping constraints, and allowable cost. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  13. Analysis of methods commonly used in biomedicine for treatment versus control comparison of very small samples.

    Science.gov (United States)

    Ristić-Djurović, Jasna L; Ćirković, Saša; Mladenović, Pavle; Romčević, Nebojša; Trbovich, Alexander M

    2018-04-01

    A rough estimate indicated that use of samples of size not larger than ten is not uncommon in biomedical research and that many of such studies are limited to strong effects due to sample sizes smaller than six. For data collected from biomedical experiments it is also often unknown if mathematical requirements incorporated in the sample comparison methods are satisfied. Computer simulated experiments were used to examine performance of methods for qualitative sample comparison and its dependence on the effectiveness of exposure, effect intensity, distribution of studied parameter values in the population, and sample size. The Type I and Type II errors, their average, as well as the maximal errors were considered. The sample size 9 and the t-test method with p = 5% ensured error smaller than 5% even for weak effects. For sample sizes 6-8 the same method enabled detection of weak effects with errors smaller than 20%. If the sample sizes were 3-5, weak effects could not be detected with an acceptable error; however, the smallest maximal error in the most general case that includes weak effects is granted by the standard error of the mean method. The increase of sample size from 5 to 9 led to seven times more accurate detection of weak effects. Strong effects were detected regardless of the sample size and method used. The minimal recommended sample size for biomedical experiments is 9. Use of smaller sizes and the method of their comparison should be justified by the objective of the experiment. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Comparison of optical methods for surface roughness characterization

    DEFF Research Database (Denmark)

    Feidenhans'l, Nikolaj Agentoft; Hansen, Poul Erik; Pilny, Lukas

    2015-01-01

    We report a study of the correlation between three optical methods for characterizing surface roughness: a laboratory scatterometer measuring the bi-directional reflection distribution function (BRDF instrument), a simple commercial scatterometer (rBRDF instrument), and a confocal optical profiler....... For each instrument, the effective range of spatial surface wavelengths is determined, and the common bandwidth used when comparing the evaluated roughness parameters. The compared roughness parameters are: the root-mean-square (RMS) profile deviation (Rq), the RMS profile slope (Rdq), and the variance...... of the scattering angle distribution (Aq). The twenty-two investigated samples were manufactured with several methods in order to obtain a suitable diversity of roughness patterns.Our study shows a one-to-one correlation of both the Rq and the Rdq roughness values when obtained with the BRDF and the confocal...

  15. A Comparison of Card-sorting Analysis Methods

    DEFF Research Database (Denmark)

    Nawaz, Ather

    2012-01-01

    This study investigates how the choice of analysis method for card sorting studies affects the suggested information structure for websites. In the card sorting technique, a variety of methods are used to analyse the resulting data. The analysis of card sorting data helps user experience (UX......) designers to discover the patterns in how users make classifications and thus to develop an optimal, user-centred website structure. During analysis, the recurrence of patterns of classification between users influences the resulting website structure. However, the algorithm used in the analysis influences...... the recurrent patterns found and thus has consequences for the resulting website design. This paper draws an attention to the choice of card sorting analysis and techniques and shows how it impacts the results. The research focuses on how the same data for card sorting can lead to different website structures...

  16. Cerebral autoregulation after subarachnoid hemorrhage: comparison of three methods

    OpenAIRE

    Budohoski, Karol P; Czosnyka, Marek; Smielewski, Peter; Varsos, Georgios V; Kasprowicz, Magdalena; Brady, Ken M; Pickard, John D; Kirkpatrick, Peter J

    2012-01-01

    In patients after subarachnoid hemorrhage (SAH) failure of cerebral autoregulation is associated with delayed cerebral ischemia (DCI). Various methods of assessing autoregulation are available, but their predictive values remain unknown. We characterize the relationship between different indices of autoregulation. Patients with SAH within 5 days were included in a prospective study. The relationship between three indices of autoregulation was analyzed: two indices calculated using spontaneous...

  17. Comparison of neutronic transport equation resolution nodal methods

    International Nuclear Information System (INIS)

    Zamonsky, O.M.; Gho, C.J.

    1990-01-01

    In this work, some transport equation resolution nodal methods are comparatively studied: the constant-constant (CC), linear-nodal (LN) and the constant-quadratic (CQ). A nodal scheme equivalent to finite differences has been used for its programming, permitting its inclusion in existing codes. Some bidimensional problems have been solved, showing that linear-nodal (LN) are, in general, obtained with accuracy in CPU shorter times. (Author) [es

  18. Comparison between two methods for resin removing after bracket debonding

    OpenAIRE

    Marchi, Rodrigo De; Marchi, Luciana Manzotti De; Terada, Raquel Sano Suga; Terada, Hélio Hissashi

    2012-01-01

    OBJECTIVE: The aim of this study was to assess - using scanning electron microscopy (SEM) - the effectiveness of two abrasive discs, one made from silicon and one from aluminum oxide, in removing adhesive remnants (AR) after debonding orthodontic brackets. METHODS: Ten randomly selected bovine teeth were used, i.e., 2 in the control group, and the other 8 divided into two groups, which had orthodontic brackets bonded to their surface with Concise Orthodontic Adhesive (3M). The following metho...

  19. Comparison of three methods to diagnose hip dysplasia in dogs

    International Nuclear Information System (INIS)

    Sharma, Vikas; Mohindroo, J.

    2009-01-01

    The present study was designed to compare the usefulness of goniometry, radiography and distraction index in diagnosis of hip dysplasia in dogs. During the study 25 clinical cases (50 joints) suspected for hip dysplasia were evaluated. Norberg angle was found to have a significant positive correlation with extension, flexion, abduction, and adduction angles and a significant negative correlation with distraction index (DI) measurements. It could be inferred that all the six parameters (NA, DI, extension, flexion, abduction, and adduction) were reliable indicators for early diagnosis of hip dysplasia.Goniometry could be used as a safe and easy method for preliminary suspicion of hip dysplasia

  20. Comparison of three analytical methods for the determination of trace elements in whole blood

    International Nuclear Information System (INIS)

    Ward, N.I.; Stephens, R.; Ryan, D.E.

    1979-01-01

    Three different analytical techniques were compared in a study of the role of trace elements in multiple sclerosis. Data for eight elements (Cd, Co, Cr, Cu, Mg, Mn, Pb, Zn) from neutron activation, flame atomic absorption and electrothermal atomic absorption methods were compared and evaluated statistically. No difference (probability less than 0.001) was observed in the elemental values obtained. Comparison of data between suitably different analytical methods gives increased confidence in the results obtained and is of particular value when standard reference materials are not available. (Auth.)

  1. Critical comparison between equation of motion-Green's function methods and configuration interaction methods: analysis of methods and applications

    International Nuclear Information System (INIS)

    Freed, K.F.; Herman, M.F.; Yeager, D.L.

    1980-01-01

    A description is provided of the common conceptual origins of many-body equations of motion and Green's function methods in Liouville operator formulations of the quantum mechanics of atomic and molecular electronic structure. Numerical evidence is provided to show the inadequacies of the traditional strictly perturbative approaches to these methods. Nonperturbative methods are introduced by analogy with techniques developed for handling large configuration interaction calculations and by evaluating individual matrix elements to higher accuracy. The important role of higher excitations is exhibited by the numerical calculations, and explicit comparisons are made between converged equations of motion and configuration interaction calculations for systems where a fundamental theorem requires the equality of the energy differences produced by these different approaches. (Auth.)

  2. Comparison between MRI-based attenuation correction methods for brain PET in dementia patients

    International Nuclear Information System (INIS)

    Cabello, Jorge; Lukas, Mathias; Pyka, Thomas; Nekolla, Stephan G.; Ziegler, Sibylle I.; Rota Kops, Elena; Shah, N. Jon; Ribeiro, Andre; Yakushev, Igor

    2016-01-01

    The combination of Positron Emission Tomography (PET) with magnetic resonance imaging (MRI) in hybrid PET/MRI scanners offers a number of advantages in investigating brain structure and function. A critical step of PET data reconstruction is attenuation correction (AC). Accounting for bone in attenuation maps (μ-map) was shown to be important in brain PET studies. While there are a number of MRI-based AC methods, no systematic comparison between them has been performed so far. The aim of this work was to study the different performance obtained by some of the recent methods presented in the literature. To perform such a comparison, we focused on [ 18 F]-Fluorodeoxyglucose-PET/MRI neurodegenerative dementing disorders, which are known to exhibit reduced levels of glucose metabolism in certain brain regions. Four novel methods were used to calculate μ-maps from MRI data of 15 patients with Alzheimer's dementia (AD). The methods cover two atlas-based methods, a segmentation method, and a hybrid template/segmentation method. Additionally, the Dixon-based and a UTE-based method, offered by a vendor, were included in the comparison. Performance was assessed at three levels: tissue identification accuracy in the μ-map, quantitative accuracy of reconstructed PET data in specific brain regions, and precision in diagnostic images at identifying hypometabolic areas. Quantitative regional errors of -20-10 % were obtained using the vendor's AC methods, whereas the novel methods produced errors in a margin of ±5 %. The obtained precision at identifying areas with abnormally low levels of glucose uptake, potentially regions affected by AD, were 62.9 and 79.5 % for the two vendor AC methods, the former ignoring bone and the latter including bone information. The precision increased to 87.5-93.3 % in average for the four new methods, exhibiting similar performances. We confirm that the AC methods based on the Dixon and UTE sequences provided by the vendor are inferior

  3. Comparison between MRI-based attenuation correction methods for brain PET in dementia patients

    Energy Technology Data Exchange (ETDEWEB)

    Cabello, Jorge; Lukas, Mathias; Pyka, Thomas; Nekolla, Stephan G.; Ziegler, Sibylle I. [Technische Universitaet Muenchen, Nuklearmedizinische Klinik und Poliklinik, Klinikum rechts der Isar, Munich (Germany); Rota Kops, Elena; Shah, N. Jon [Forschungszentrum Juelich GmbH, Institute of Neuroscience and Medicine 4, Medical Imaging Physics, Juelich (Germany); Ribeiro, Andre [Forschungszentrum Juelich GmbH, Institute of Neuroscience and Medicine 4, Medical Imaging Physics, Juelich (Germany); Institute of Biophysics and Biomedical Engineering, Lisbon (Portugal); Yakushev, Igor [Technische Universitaet Muenchen, Nuklearmedizinische Klinik und Poliklinik, Klinikum rechts der Isar, Munich (Germany); Institute TUM Neuroimaging Center (TUM-NIC), Munich (Germany)

    2016-11-15

    The combination of Positron Emission Tomography (PET) with magnetic resonance imaging (MRI) in hybrid PET/MRI scanners offers a number of advantages in investigating brain structure and function. A critical step of PET data reconstruction is attenuation correction (AC). Accounting for bone in attenuation maps (μ-map) was shown to be important in brain PET studies. While there are a number of MRI-based AC methods, no systematic comparison between them has been performed so far. The aim of this work was to study the different performance obtained by some of the recent methods presented in the literature. To perform such a comparison, we focused on [{sup 18}F]-Fluorodeoxyglucose-PET/MRI neurodegenerative dementing disorders, which are known to exhibit reduced levels of glucose metabolism in certain brain regions. Four novel methods were used to calculate μ-maps from MRI data of 15 patients with Alzheimer's dementia (AD). The methods cover two atlas-based methods, a segmentation method, and a hybrid template/segmentation method. Additionally, the Dixon-based and a UTE-based method, offered by a vendor, were included in the comparison. Performance was assessed at three levels: tissue identification accuracy in the μ-map, quantitative accuracy of reconstructed PET data in specific brain regions, and precision in diagnostic images at identifying hypometabolic areas. Quantitative regional errors of -20-10 % were obtained using the vendor's AC methods, whereas the novel methods produced errors in a margin of ±5 %. The obtained precision at identifying areas with abnormally low levels of glucose uptake, potentially regions affected by AD, were 62.9 and 79.5 % for the two vendor AC methods, the former ignoring bone and the latter including bone information. The precision increased to 87.5-93.3 % in average for the four new methods, exhibiting similar performances. We confirm that the AC methods based on the Dixon and UTE sequences provided by the vendor are

  4. Methods to study postprandial lipemia

    DEFF Research Database (Denmark)

    Ooi, Teik Chye; Nordestgaard, Børge G

    2011-01-01

    to the liver. In general, PPL occurs over 4-6 h in normal individuals, depending on the amount and type of fats consumed. The complexity of PPL changes is compounded by ingestion of food before the previous meal is fully processed. PPL testing is done to determine the impact of (a) exogenous factors...... such as the amount and type of food consumed, and (b) endogenous factors such as the metabolic/genetic status of the subjects, on PPL. To study PPL appropriately, different methods are used to suit the study goal. This paper provides an overview of the methodological aspects of PPL testing. It deals with markers...

  5. On solutions of stochastic oscillatory quadratic nonlinear equations using different techniques, a comparison study

    International Nuclear Information System (INIS)

    El-Tawil, M A; Al-Jihany, A S

    2008-01-01

    In this paper, nonlinear oscillators under quadratic nonlinearity with stochastic inputs are considered. Different methods are used to obtain first order approximations, namely, the WHEP technique, the perturbation method, the Pickard approximations, the Adomian decompositions and the homotopy perturbation method (HPM). Some statistical moments are computed for the different methods using mathematica 5. Comparisons are illustrated through figures for different case-studies

  6. Comparison of deterministic and stochastic methods for time-dependent Wigner simulations

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Sihong, E-mail: sihong@math.pku.edu.cn [LMAM and School of Mathematical Sciences, Peking University, Beijing 100871 (China); Sellier, Jean Michel, E-mail: jeanmichel.sellier@parallel.bas.bg [IICT, Bulgarian Academy of Sciences, Acad. G. Bonchev str. 25A, 1113 Sofia (Bulgaria)

    2015-11-01

    Recently a Monte Carlo method based on signed particles for time-dependent simulations of the Wigner equation has been proposed. While it has been thoroughly validated against physical benchmarks, no technical study about its numerical accuracy has been performed. To this end, this paper presents the first step towards the construction of firm mathematical foundations for the signed particle Wigner Monte Carlo method. An initial investigation is performed by means of comparisons with a cell average spectral element method, which is a highly accurate deterministic method and utilized to provide reference solutions. Several different numerical tests involving the time-dependent evolution of a quantum wave-packet are performed and discussed in deep details. In particular, this allows us to depict a set of crucial criteria for the signed particle Wigner Monte Carlo method to achieve a satisfactory accuracy.

  7. SPACE CHARGE SIMULATION METHODS INCORPORATED IN SOME MULTI - PARTICLE TRACKING CODES AND THEIR RESULTS COMPARISON

    International Nuclear Information System (INIS)

    BEEBE - WANG, J.; LUCCIO, A.U.; D IMPERIO, N.; MACHIDA, S.

    2002-01-01

    Space charge in high intensity beams is an important issue in accelerator physics. Due to the complicity of the problems, the most effective way of investigating its effect is by computer simulations. In the resent years, many space charge simulation methods have been developed and incorporated in various 2D or 3D multi-particle-tracking codes. It has becoming necessary to benchmark these methods against each other, and against experimental results. As a part of global effort, we present our initial comparison of the space charge methods incorporated in simulation codes ORBIT++, ORBIT and SIMPSONS. In this paper, the methods included in these codes are overviewed. The simulation results are presented and compared. Finally, from this study, the advantages and disadvantages of each method are discussed

  8. SPACE CHARGE SIMULATION METHODS INCORPORATED IN SOME MULTI - PARTICLE TRACKING CODES AND THEIR RESULTS COMPARISON.

    Energy Technology Data Exchange (ETDEWEB)

    BEEBE - WANG,J.; LUCCIO,A.U.; D IMPERIO,N.; MACHIDA,S.

    2002-06-03

    Space charge in high intensity beams is an important issue in accelerator physics. Due to the complicity of the problems, the most effective way of investigating its effect is by computer simulations. In the resent years, many space charge simulation methods have been developed and incorporated in various 2D or 3D multi-particle-tracking codes. It has becoming necessary to benchmark these methods against each other, and against experimental results. As a part of global effort, we present our initial comparison of the space charge methods incorporated in simulation codes ORBIT++, ORBIT and SIMPSONS. In this paper, the methods included in these codes are overviewed. The simulation results are presented and compared. Finally, from this study, the advantages and disadvantages of each method are discussed.

  9. Comparison of Machine Learning Methods for the Arterial Hypertension Diagnostics

    Directory of Open Access Journals (Sweden)

    Vladimir S. Kublanov

    2017-01-01

    Full Text Available The paper presents results of machine learning approach accuracy applied analysis of cardiac activity. The study evaluates the diagnostics possibilities of the arterial hypertension by means of the short-term heart rate variability signals. Two groups were studied: 30 relatively healthy volunteers and 40 patients suffering from the arterial hypertension of II-III degree. The following machine learning approaches were studied: linear and quadratic discriminant analysis, k-nearest neighbors, support vector machine with radial basis, decision trees, and naive Bayes classifier. Moreover, in the study, different methods of feature extraction are analyzed: statistical, spectral, wavelet, and multifractal. All in all, 53 features were investigated. Investigation results show that discriminant analysis achieves the highest classification accuracy. The suggested approach of noncorrelated feature set search achieved higher results than data set based on the principal components.

  10. 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.

  11. Self-compacting concretes (SCC: comparison of methods of dosage

    Directory of Open Access Journals (Sweden)

    B. F. Tutikian

    Full Text Available The composition of a self-compacting concrete (SCC should be defined to fulfills a number of requirements, such as self-compactibility, strength and durability. This study aims to compare three methods of dosage for SCC with local materials, so as to determine which one is the most economical and rational, thus assisting the executor in making a decision and enabling economic and technical feasibility for its application. The methods used in the experimental program were: Nan Su et al., which was developed in 2001 [1]; Repette-Melo, which was proposed in 2005 [2]; and Tutikian & Dal Molin, which was developed in 2007 [3]. From the results obtained in the experimental program, it was observed that the method which presented the lowest cost and highest compressive strength at the ages of 7, 28 and 91 days was Tutikian & Dal Molin, while the one which reached the lowest chloride ion penetration, best compactness and highest elasticity modulus was Repette-Melo. In tests carried out in the fresh state, all tested methods yielded mixtures which comply with the self-compactibility levels required by ABNT NBR 15823:2010 [4].

  12. Quantitative assessment of breast density: comparison of different methods

    International Nuclear Information System (INIS)

    Qin Naishan; Guo Li; Dang Yi; Song Luxin; Wang Xiaoying

    2011-01-01

    Objective: To Compare different methods of quantitative breast density measurement. Methods: The study included sixty patients who underwent both mammography and breast MRI. The breast density was computed automatically on digital mammograms with R2 workstation, Two experienced radiologists read the mammograms and assessed the breast density with Wolfe and ACR classification respectively. Fuzzy C-means clustering algorithm (FCM) was used to assess breast density on MRI. Each assessment method was repeated after 2 weeks. Spearman and Pearson correlations of inter- and intrareader and intermodality were computed for density estimates. Results: Inter- and intrareader correlation of Wolfe classification were 0.74 and 0.65, and they were 0.74 and 0.82 for ACR classification respectively. Correlation between Wolfe and ACR classification was 0.77. High interreader correlation of 0.98 and intrareader correlation of 0.96 was observed with MR FCM measurement. And the correlation between digital mammograms and MRI was high in the assessment of breast density (r=0.81, P<0.01). Conclusion: High correlation of breast density estimates on digital mammograms and MRI FCM suggested the former could be used as a simple and accurate method. (authors)

  13. Comparison Of Different Methods For The Swimming Aerobic Capacity Evaluation.

    Science.gov (United States)

    Pelarigo, Jailton Gregório; Fernandes, Ricardo Jorge; Ribeiro, João; Denadai, Benedito Sérgio; Greco, Camila Coelho; Vilas-Boas, João Paulo

    2017-02-23

    This study compared velocity (v) and bioenergetical factors using different methods applied for the swimming aerobic capacity evaluation. Ten elite female swimmers (17.6 ± 1.9 yrs., 1.70 ± 0.05 m and 61.3 ± 5.8 kg) performed an intermittent incremental velocity protocol until voluntary exhaustion to determine the v associated to the individual anaerobic threshold (IAnT), ventilatory threshold (VT), heart rate threshold (HRT), lactate threshold fixed in 3.5 mmol.L (LT3.5) and maximal oxygen uptake (V[Combining Dot Above]O2max). Two-to-three 30 min submaximal constant tests for the v assessment at maximal lactate steady state (MLSS). The v, gas exchange, heart rate and blood lactate concentration variables were monitored in all tests. The values of all parameters at the v corresponding to MLSS, IAnT, VT and HRT were similar (p 0.400), except for carbon dioxide (V[Combining Dot Above]CO2) that was higher for MLSS compared to VT (p higher when compared to other methods for v and bioenergetical factors. It is suggested that IAnT, VT and HRT methods are better predictors of the intensity corresponding to the commonly accepted gold-standard method (i.e. MLSS) for the aerobic capacity evaluation compared to LT3.5.

  14. Comparison of dosimetric methods for virtual wedge analysis

    International Nuclear Information System (INIS)

    Bailey, M.; Nelson, V.; Collins, O.; West, M.; Holloway, L.; Rajapaske, S.; Arts, J.; Varas, J.; Cho, G.; Hill, R.

    2004-01-01

    Full text: The Siemens Virtual Wedge (Concord, USA) creates wedged beam profile by moving a single collimator jaw across the specified field size whilst varying the dose rate and jaw speed for use in the delivery of radiotherapy treatments. The measurement of the dosimetric characteristics of the Siemens Virtual Wedge poses significant challenges to medical physicists. This study investigates several different methods for measuring and analysing the virtual wedge for data collection for treatment planning systems and ongoing quality assurance. The beam profiles of the Virtual Wedge (VW) were compared using several different dosimetric methods. Open field profiles were measured with Kodak X-Omat V (Rochester, NY, USA) radiographic film and compared with measurements made using the Sun Nuclear Profiler with a Motorized Drive Assembly (MDA) (Melbourne, FL, USA) and the Scanditronix Wellhofer CC13 ionisation chamber and 24 ion Chamber Array (CA24) (Schwarzenbruck, Germany). The resolution of each dosimetric method for open field profiles was determined. The Virtual Wedge profiles were measured with radiographic film the Profiler and the Scanditronix Wellhofer CA 24 ion Chamber Array at 5 different depths. The ease of setup, time taken, analysis and accuracy of measurement were all evaluated to determine the method that would be both appropriate and practical for routine quality assurance of the Virtual Wedge. The open field profiles agreed within ±2% or 2mm for all dosimetric methods. The accuracy of the Profiler and CA24 are limited to half of the step size selected for each of these detectors. For the VW measurements a step size of 2mm was selected for the Profiler and the CA24. The VW profiles for all dosimetric methods agreed within ±2% or 2mm for the main wedged section of the profile. The toe and heel ends of the wedges showed the significant discrepancies dependent upon the dosimetry method used, up to 7% for the toe end with the CA24. The dosimetry of the

  15. Detection of circulating immune complexes by Raji cell assay: comparison of flow cytometric and radiometric methods

    International Nuclear Information System (INIS)

    Kingsmore, S.F.; Crockard, A.D.; Fay, A.C.; McNeill, T.A.; Roberts, S.D.; Thompson, J.M.

    1988-01-01

    Several flow cytometric methods for the measurement of circulating immune complexes (CIC) have recently become available. We report a Raji cell flow cytometric assay (FCMA) that uses aggregated human globulin (AHG) as primary calibrator. Technical advantages of the Raji cell flow cytometric assay are discussed, and its clinical usefulness is evaluated in a method comparison study with the widely used Raji cell immunoradiometric assay. FCMA is more precise and has greater analytic sensitivity for AHG. Diagnostic sensitivity by the flow cytometric method is superior in systemic lupus erythematosus (SLE), rheumatoid arthritis, and vasculitis patients: however, diagnostic specificity is similar for both assays, but the reference interval of FCMA is narrower. Significant correlations were found between CIC levels obtained with both methods in SLE, rheumatoid arthritis, and vasculitis patients and in longitudinal studies of two patients with cerebral SLE. The Raji cell FCMA is recommended for measurement of CIC levels to clinical laboratories with access to a flow cytometer

  16. Technical and economic comparison of irradiation and conventional methods

    International Nuclear Information System (INIS)

    1988-04-01

    Radiation processing is based on the use of ionizing radiation (gamma radiation, high energy electrons) as a source of energy in different industrial applications. For about 30 years of steady growth it became almost routine in a number of industrial processes. The growth resulted, among other things, from the availability of radiation sources matching requirements of industrial production and from the wide basis of fundamental and applied radiation research. The most important, however, was the fact that radiation processing proved in practice to be safe, reliable, easy to control, and economical. In comparison with other competitive techniques, it also offered a better alternative from the viewpoint of occupational safety and environmental considerations. In order to review the current status of comparative analysis of radiation and competitive techniques from the technological and economic viewpoint, the Agency convened an Advisory Group in Dubrovnik, Yugoslavia, 6-8 October 1986. The present publication is based on contributions presented at the meeting, discussions held at the meeting, and subsequent editing work. It is expected that this updated technological and economic comparative analysis will provide useful information for all those who are implementing or considering the introduction of radiation processing to industry. The presented data may be essential for decision makers and could contribute to all feasibility and pre-investment studies. As such, this publication is expected to promote industrially oriented projects based on radiation processing techniques. The actual figures given in the individual reports are as accurate as possible. However, it should be understood that time factor and local conditions may play a significant role and corresponding adjustment may be required. Refs, figs and tabs

  17. Comparison of tissue processing methods for microvascular visualization in axolotls.

    Science.gov (United States)

    Montoro, Rodrigo; Dickie, Renee

    2017-01-01

    The vascular system, the pipeline for oxygen and nutrient delivery to tissues, is essential for vertebrate development, growth, injury repair, and regeneration. With their capacity to regenerate entire appendages throughout their lifespan, axolotls are an unparalleled model for vertebrate regeneration, but they lack many of the molecular tools that facilitate vascular imaging in other animal models. The determination of vascular metrics requires high quality image data for the discrimination of vessels from background tissue. Quantification of the vasculature using perfused, cleared specimens is well-established in mammalian systems, but has not been widely employed in amphibians. The objective of this study was to optimize tissue preparation methods for the visualization of the microvascular network in axolotls, providing a basis for the quantification of regenerative angiogenesis. To accomplish this aim, we performed intracardiac perfusion of pigment-based contrast agents and evaluated aqueous and non-aqueous clearing techniques. The methods were verified by comparing the quality of the vascular images and the observable vascular density across treatment groups. Simple and inexpensive, these tissue processing techniques will be of use in studies assessing vascular growth and remodeling within the context of regeneration. Advantages of this method include: •Higher contrast of the vasculature within the 3D context of the surrounding tissue •Enhanced detection of microvasculature facilitating vascular quantification •Compatibility with other labeling techniques.

  18. Rigid inclusions-Comparison between analytical and numerical methods

    International Nuclear Information System (INIS)

    Gomez Perez, R.; Melentijevic, S.

    2014-01-01

    This paper compares different analytical methods for analysis of rigid inclusions with finite element modeling. First of all, the load transfer in the distribution layer is analyzed for its different thicknesses and different inclusion grids to define the range between results obtained by analytical and numerical methods. The interaction between the soft soil and the inclusion in the estimation of settlements is studied as well. Considering different stiffness of the soft soil, settlements obtained analytical and numerically are compared. The influence of the soft soil modulus of elasticity on the neutral point depth was also performed by finite elements. This depth has a great importance for the definition of the total length of rigid inclusion. (Author)

  19. The choice of statistical methods for comparisons of dosimetric data in radiotherapy.

    Science.gov (United States)

    Chaikh, Abdulhamid; Giraud, Jean-Yves; Perrin, Emmanuel; Bresciani, Jean-Pierre; Balosso, Jacques

    2014-09-18

    Novel irradiation techniques are continuously introduced in radiotherapy to optimize the accuracy, the security and the clinical outcome of treatments. These changes could raise the question of discontinuity in dosimetric presentation and the subsequent need for practice adjustments in case of significant modifications. This study proposes a comprehensive approach to compare different techniques and tests whether their respective dose calculation algorithms give rise to statistically significant differences in the treatment doses for the patient. Statistical investigation principles are presented in the framework of a clinical example based on 62 fields of radiotherapy for lung cancer. The delivered doses in monitor units were calculated using three different dose calculation methods: the reference method accounts the dose without tissues density corrections using Pencil Beam Convolution (PBC) algorithm, whereas new methods calculate the dose with tissues density correction for 1D and 3D using Modified Batho (MB) method and Equivalent Tissue air ratio (ETAR) method, respectively. The normality of the data and the homogeneity of variance between groups were tested using Shapiro-Wilks and Levene test, respectively, then non-parametric statistical tests were performed. Specifically, the dose means estimated by the different calculation methods were compared using Friedman's test and Wilcoxon signed-rank test. In addition, the correlation between the doses calculated by the three methods was assessed using Spearman's rank and Kendall's rank tests. The Friedman's test showed a significant effect on the calculation method for the delivered dose of lung cancer patients (p Wilcoxon signed-rank test of paired comparisons indicated that the delivered dose was significantly reduced using density-corrected methods as compared to the reference method. Spearman's and Kendall's rank tests indicated a positive correlation between the doses calculated with the different methods

  20. Stochastic spectral Galerkin and collocation methods for PDEs with random coefficients: A numerical comparison

    KAUST Repository

    Bä ck, Joakim; Nobile, Fabio; Tamellini, Lorenzo; Tempone, Raul

    2010-01-01

    Much attention has recently been devoted to the development of Stochastic Galerkin (SG) and Stochastic Collocation (SC) methods for uncertainty quantification. An open and relevant research topic is the comparison of these two methods

  1. Cost comparison between Subterrene and current tunneling methods. Final report

    International Nuclear Information System (INIS)

    Bledsoe, J.D.; Hill, J.E.; Coon, R.F.

    1975-05-01

    A study was made to compare tunnel construction costs between the Subterrene tunneling system and methods currently in use. Three completed tunnels were selected for study cases to represent finished diameters ranging from 3.05 meters (10 feet) to 6.25 meters (20.5 feet). The study cases were normalized by deleting extraneous work and assigning labor, equipment, and materials costs for the Southern California area in 1974. Detailed cost estimates (shown in Appendix A) were then made for the three tunnels for baseline. A conceptual nuclear powered Subterrene tunneling machine (NSTM) was designed. It was assumed that NSTM's were available for each of the three baseline tunnels. Costs were estimated (shown in Appendix B) for the baseline tunnels driven by NSTM

  2. A comparison of methods to predict historical daily streamflow time series in the southeastern United States

    Science.gov (United States)

    Farmer, William H.; Archfield, Stacey A.; Over, Thomas M.; Hay, Lauren E.; LaFontaine, Jacob H.; Kiang, Julie E.

    2015-01-01

    Effective and responsible management of water resources relies on a thorough understanding of the quantity and quality of available water. Streamgages cannot be installed at every location where streamflow information is needed. As part of its National Water Census, the U.S. Geological Survey is planning to provide streamflow predictions for ungaged locations. In order to predict streamflow at a useful spatial and temporal resolution throughout the Nation, efficient methods need to be selected. This report examines several methods used for streamflow prediction in ungaged basins to determine the best methods for regional and national implementation. A pilot area in the southeastern United States was selected to apply 19 different streamflow prediction methods and evaluate each method by a wide set of performance metrics. Through these comparisons, two methods emerged as the most generally accurate streamflow prediction methods: the nearest-neighbor implementations of nonlinear spatial interpolation using flow duration curves (NN-QPPQ) and standardizing logarithms of streamflow by monthly means and standard deviations (NN-SMS12L). It was nearly impossible to distinguish between these two methods in terms of performance. Furthermore, neither of these methods requires significantly more parameterization in order to be applied: NN-SMS12L requires 24 regional regressions—12 for monthly means and 12 for monthly standard deviations. NN-QPPQ, in the application described in this study, required 27 regressions of particular quantiles along the flow duration curve. Despite this finding, the results suggest that an optimal streamflow prediction method depends on the intended application. Some methods are stronger overall, while some methods may be better at predicting particular statistics. The methods of analysis presented here reflect a possible framework for continued analysis and comprehensive multiple comparisons of methods of prediction in ungaged basins (PUB

  3. Automation of the method gamma of comparison dosimetry images

    International Nuclear Information System (INIS)

    Moreno Reyes, J. C.; Macias Jaen, J.; Arrans Lara, R.

    2013-01-01

    The objective of this work was the development of JJGAMMA application analysis software, which enables this task systematically, minimizing intervention specialist and therefore the variability due to the observer. Both benefits, allow comparison of images is done in practice with the required frequency and objectivity. (Author)

  4. Comparison of DUPIC fuel composition heterogeneity control methods

    International Nuclear Information System (INIS)

    Choi, Hang Bok; Ko, Won Il

    1999-08-01

    A method to reduce the fuel composition heterogeneity effect on the core performance parameters has been studied for the DUPIC fuel which is made of spent pressurized water reactor (PWR) fuels by a dry refabrication process. This study focuses on the reactivity control method which uses either slightly enriched, depleted, or natural uranium to minimize the cost rise effect on the manufacturing of DUPIC fuel, when adjusting the excess reactivity control by slightly enriched and depleted uranium, reactivity control by natural uranium for high reactivity spent PWR fuels, and reactivity control by natural uranium for linear reactivity spent PWR fuels. The results of this study have shown that the reactivity control by slightly enriched and depleted uranium, all the spent PWR fuels can be utilized as the DUPIC fuel and the fraction of fresh uranium feed is 3.4% on an average. For the reactivity control by natural uranium, about 88% of spent PWR fuel can be utilized as the DUPIC fuel when the linear reactivity spent PWR fuels are used, and the amount of natural uranium feed needed to control the DUPIC fuel reactivity is negligible. (author). 13 refs., 16 tabs., 6 figs

  5. Comparison of DUPIC fuel composition heterogeneity control methods

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hang Bok; Ko, Won Il [Korea Atomic Energy Research Institute, Taejon (Korea)

    1999-08-01

    A method to reduce the fuel composition heterogeneity effect on the core performance parameters has been studied for the DUPIC fuel which is made of spent pressurized water reactor (PWR) fuels by a dry refabrication process. This study focuses on the reactivity control method which uses either slightly enriched, depleted, or natural uranium to minimize the cost rise effect on the manufacturing of DUPIC fuel, when adjusting the excess reactivity of the spent PWR fuel. In order to reduce the variation of isotopic composition of the DUPIC fuel, the inter-assembly mixing operation was taken three times. Then, three options have been considered: reactivity control by slightly enriched and depleted uranium, reactivity control by natural uranium for high reactivity spent PWR fuels, and reactivity control by natural uranium for linear reactivity spent PWR fuels. The results of this study have shown that the reactivity of DUPIC fuel can be tightly controlled with the minimum amount of fresh uranium feed. For the reactivity control by slightly enriched and depleted uranium, all the spent PWR fuels can be utilized as the DUPIC fuel and the fraction of fresh uranium feed is 3.4% on an average. For the reactivity control by natural uranium, about 88% of spent PWR fuel can be utilized as the DUPIC fuel when the linear reactivity spent PWR fuels are used, and the amount of natural uranium feed needed to control the DUPIC fuel reactivity is negligible. 13 refs., 6 figs., 16 tabs. (Author)

  6. Review and comparison of recent methods in space geodesy

    International Nuclear Information System (INIS)

    Varga, M.

    1983-01-01

    The study of geodynamic processes requires the application of new space-born geodesic measuring methods. A terrestrial reference system (TRS) is required for describing geodynamic processes. For this purpose satisfactory knowledge of polar motions, Earth rotation and tidal forces determined by laser, global positioning system (GPS) and VLBI measurements are needed. In addition, gravity and magnetic field of the Earth have to be known, modelled by using satellite to satellite traching (SST), altimetry, gradiometry and magnetometry results. Motions of the Earth-Moon system, as well as the relation between the terrestrial reference system and the inertial system can be determined by means of VLBI measurements. (author)

  7. Calibrations of pocket dosemeters using a comparison method

    International Nuclear Information System (INIS)

    Somarriba V, I.

    1996-01-01

    This monograph is dedicated mainly to the calibration of pocket dosemeters. Various types of radiation sources used in hospitals and different radiation detectors with emphasis on ionization chambers are briefly presented. Calibration methods based on the use of a reference dosemeter were developed to calibrate all pocket dosemeters existing at the Radiation Physics and Metrology Laboratory. Some of these dosemeters were used in personnel dosimetry at hospitals. Moreover, a study was realized about factors that affect the measurements with pocket dosemeters in the long term, such as discharges due to cosmic radiation. A DBASE IV program was developed to store the information included in the hospital's registry

  8. Comparison of Particulate Mercury Measured with Manual and Automated Methods

    Directory of Open Access Journals (Sweden)

    Rachel Russo

    2011-01-01

    Full Text Available A study was conducted to compare measuring particulate mercury (HgP with the manual filter method and the automated Tekran system. Simultaneous measurements were conducted with the Tekran and Teflon filter methodologies in the marine and coastal continental atmospheres. Overall, the filter HgP values were on the average 21% higher than the Tekran HgP, and >85% of the data were outside of ±25% region surrounding the 1:1 line. In some cases the filter values were as much as 3-fold greater, with

  9. Bearing-only SLAM: comparison between probabilistic and deterministic methods

    OpenAIRE

    Joly , Cyril; Rives , Patrick

    2008-01-01

    This work deals with the problem of simultaneous localization and mapping (SLAM). Classical methods for solving the SLAM problem are based on the Extended Kalman Filter (EKF-SLAM) or particle filter (FastSLAM). These kinds of algorithms allow on-line solving but could be inconsistent. In this report, the above-mentioned algorithms are not studied but global ones. Global approaches need all measurements from the initial step to the final step in order to compute the trajectory of the robot and...

  10. A Comparison of Methods for Estimating the Determinant of High-Dimensional Covariance Matrix

    KAUST Repository

    Hu, Zongliang

    2017-09-27

    The determinant of the covariance matrix for high-dimensional data plays an important role in statistical inference and decision. It has many real applications including statistical tests and information theory. Due to the statistical and computational challenges with high dimensionality, little work has been proposed in the literature for estimating the determinant of high-dimensional covariance matrix. In this paper, we estimate the determinant of the covariance matrix using some recent proposals for estimating high-dimensional covariance matrix. Specifically, we consider a total of eight covariance matrix estimation methods for comparison. Through extensive simulation studies, we explore and summarize some interesting comparison results among all compared methods. We also provide practical guidelines based on the sample size, the dimension, and the correlation of the data set for estimating the determinant of high-dimensional covariance matrix. Finally, from a perspective of the loss function, the comparison study in this paper may also serve as a proxy to assess the performance of the covariance matrix estimation.

  11. A Comparison of Methods for Estimating the Determinant of High-Dimensional Covariance Matrix.

    Science.gov (United States)

    Hu, Zongliang; Dong, Kai; Dai, Wenlin; Tong, Tiejun

    2017-09-21

    The determinant of the covariance matrix for high-dimensional data plays an important role in statistical inference and decision. It has many real applications including statistical tests and information theory. Due to the statistical and computational challenges with high dimensionality, little work has been proposed in the literature for estimating the determinant of high-dimensional covariance matrix. In this paper, we estimate the determinant of the covariance matrix using some recent proposals for estimating high-dimensional covariance matrix. Specifically, we consider a total of eight covariance matrix estimation methods for comparison. Through extensive simulation studies, we explore and summarize some interesting comparison results among all compared methods. We also provide practical guidelines based on the sample size, the dimension, and the correlation of the data set for estimating the determinant of high-dimensional covariance matrix. Finally, from a perspective of the loss function, the comparison study in this paper may also serve as a proxy to assess the performance of the covariance matrix estimation.

  12. A Comparison of Methods for Estimating the Determinant of High-Dimensional Covariance Matrix

    KAUST Repository

    Hu, Zongliang; Dong, Kai; Dai, Wenlin; Tong, Tiejun

    2017-01-01

    The determinant of the covariance matrix for high-dimensional data plays an important role in statistical inference and decision. It has many real applications including statistical tests and information theory. Due to the statistical and computational challenges with high dimensionality, little work has been proposed in the literature for estimating the determinant of high-dimensional covariance matrix. In this paper, we estimate the determinant of the covariance matrix using some recent proposals for estimating high-dimensional covariance matrix. Specifically, we consider a total of eight covariance matrix estimation methods for comparison. Through extensive simulation studies, we explore and summarize some interesting comparison results among all compared methods. We also provide practical guidelines based on the sample size, the dimension, and the correlation of the data set for estimating the determinant of high-dimensional covariance matrix. Finally, from a perspective of the loss function, the comparison study in this paper may also serve as a proxy to assess the performance of the covariance matrix estimation.

  13. Comparison of three methods of feeding colostrum to dairy calves.

    Science.gov (United States)

    Besser, T E; Gay, C C; Pritchett, L

    1991-02-01

    Absorption of colostral immunoglobulins by Holstein calves was studied in 3 herds in which 3 methods of colostrum feeding were used. Failure of passive transfer, as determined by calf serum immunoglobulin G1 (IgG1) concentration less than 10 mg/ml at 48 hours of age, was diagnosed in 61.4% of calves from a dairy in which calves were nursed by their dams, 19.3% of calves from a dairy using nipple-bottle feeding, and 10.8% of calves from a dairy using tube feeding. The management factor determined to have the greatest influence on the probability of failure of passive transfer in the herds using artificial methods of colostrum feeding (bottle feeding or tube feeding) was the volume of colostrum fed as it affected the amount of IgG1 received by the calf. In dairies that used artificial feeding methods, failure of passive transfer was infrequent in calves fed greater than or equal to 100 g IgG1 in the first colostrum feeding. In the dairy that allowed calves to suckle, prevalence of failure of passive transfer was greater than 50% even among calves nursed by cows with above-average colostral IgG1 concentration. Analysis of the effect of other management factors on calf immunoglobulin absorption revealed small negative effects associated with the use of previously frozen colostrum and the use of colostrum from cows with long nonlactating intervals.

  14. Superhydrophobic transparent films from silica powder: Comparison of fabrication methods

    KAUST Repository

    Liu, Li-Der; Lin, Chao-Sung; Tikekar, Mukul; Chen, Ping-Hei

    2011-01-01

    The lotus leaf is known for its self-clean, superhydrophobic surface, which displays a hierarchical structure covered with a thin wax-like material. In this study, three fabrication techniques, using silicon dioxide particles to create surface roughness followed by a surface modification with a film of polydimethylsiloxane, were applied on a transparent glass substrate. The fabrication techniques differed mainly on the deposition of silicon dioxide particles, which included organic, inorganic, and physical methods. Each technique was used to coat three samples of varying particle load. The surface of each sample was evaluated with contact angle goniometer and optical spectrometer. Results confirmed the inverse relationships between contact angle and optical transmissivity independent of fabrication techniques. Microstructural morphologies also suggested the advantage of physical deposition over chemical methods. In summary, the direct sintering method proved outstanding for its contact angle vs transmissivity efficiency, and capable of generating a contact angle as high as 174°. © 2011 Elsevier B.V. All rights reserved.

  15. Superhydrophobic transparent films from silica powder: Comparison of fabrication methods

    KAUST Repository

    Liu, Li-Der

    2011-07-01

    The lotus leaf is known for its self-clean, superhydrophobic surface, which displays a hierarchical structure covered with a thin wax-like material. In this study, three fabrication techniques, using silicon dioxide particles to create surface roughness followed by a surface modification with a film of polydimethylsiloxane, were applied on a transparent glass substrate. The fabrication techniques differed mainly on the deposition of silicon dioxide particles, which included organic, inorganic, and physical methods. Each technique was used to coat three samples of varying particle load. The surface of each sample was evaluated with contact angle goniometer and optical spectrometer. Results confirmed the inverse relationships between contact angle and optical transmissivity independent of fabrication techniques. Microstructural morphologies also suggested the advantage of physical deposition over chemical methods. In summary, the direct sintering method proved outstanding for its contact angle vs transmissivity efficiency, and capable of generating a contact angle as high as 174°. © 2011 Elsevier B.V. All rights reserved.

  16. Comparison of local International Sensitivity Index calibration and 'Direct INR' methods in correction of locally reported International Normalized Ratios: an international study. On behalf of the European Action of Anticoagulation

    DEFF Research Database (Denmark)

    Poller, L; Keown, M; Ibrahim, S

    2007-01-01

    collaborative study at 77 centers has compared local INR correction using the two alternative methods recommended in the Scientific and Standardization Committee of the International Society on Thrombosis and Haemostasis guidelines: local ISI calibration and 'Direct INR'. METHODS: Success of INR correction...

  17. Comparison of System Identification Methods using Ambient Bridge Test Data

    DEFF Research Database (Denmark)

    Andersen, P.; Brincker, Rune; Peeters, B.

    1999-01-01

    In this paper the performance of four different system identification methods is compared using operational data obtained from an ambient vibration test of the Swiss Z24 highway bridge. The four methods are the frequency domain based peak-picking methods, the polyreference LSCE method, the stocha......In this paper the performance of four different system identification methods is compared using operational data obtained from an ambient vibration test of the Swiss Z24 highway bridge. The four methods are the frequency domain based peak-picking methods, the polyreference LSCE method...

  18. A comparison theorem for the SOR iterative method

    Science.gov (United States)

    Sun, Li-Ying

    2005-09-01

    In 1997, Kohno et al. have reported numerically that the improving modified Gauss-Seidel method, which was referred to as the IMGS method, is superior to the SOR iterative method. In this paper, we prove that the spectral radius of the IMGS method is smaller than that of the SOR method and Gauss-Seidel method, if the relaxation parameter [omega][set membership, variant](0,1]. As a result, we prove theoretically that this method is succeeded in improving the convergence of some classical iterative methods. Some recent results are improved.

  19. A comparison of methods of assessment of scintigraphic colon transit.

    Science.gov (United States)

    Freedman, Patricia Noel; Goldberg, Paul A; Fataar, Abdul Basier; Mann, Michael M

    2006-06-01

    There is no standard method of analysis of scintigraphic colonic transit investigation. This study was designed to compare 4 techniques. Sixteen subjects (median age, 37.5 y; range, 21-61 y), who had sustained a spinal cord injury more than a year before the study, were given a pancake labeled with 10-18 MBq of (111)In bound to resin beads to eat. Anterior and posterior images were acquired with a gamma-camera 3 h after the meal and then 3 times a day for the next 4 d. Seven regions of interest, outlining the ascending colon, hepatic flexure, transverse colon, splenic flexure, descending colon, rectosigmoid, and total abdominal activity at each time point, were drawn on the anterior and posterior images. The counts were decay corrected and the geometric mean (GM), for each region, at each time point calculated. The GM was used to calculate the percentage of the initial total abdominal activity in each region, at each time point. Colonic transit was assessed in 4 ways: (a) Three independent nuclear medicine physicians visually assessed transit on the analog images and classified subjects into 5 categories of colonic transit (rapid, intermediate, generalized delay, right-sided delay, or left-sided delay). (b) Parametric images were constructed from the percentage activity in each region at each time point. (c) The arrival and clearance times of the activity in the right and left colon were plotted as time-activity curves. (d) The geometric center of the distribution of the activity was calculated and plotted on a graph versus time. The results of these 4 methods were compared using an agreement matrix. Though simple to perform, the visual assessment was unreliable. The best agreement occurred between the parametric images and the arrival and clearance times of the activity in the right and left colon. The different methods of assessment do not produce uniform results. The best option for evaluating colonic transit appears to be a combination of the analog images

  20. A comparison between progressive extension method (PEM) and iterative method (IM) for magnetic field extrapolations in the solar atmosphere

    Science.gov (United States)

    Wu, S. T.; Sun, M. T.; Sakurai, Takashi

    1990-01-01

    This paper presents a comparison between two numerical methods for the extrapolation of nonlinear force-free magnetic fields, viz the Iterative Method (IM) and the Progressive Extension Method (PEM). The advantages and disadvantages of these two methods are summarized, and the accuracy and numerical instability are discussed. On the basis of this investigation, it is claimed that the two methods do resemble each other qualitatively.

  1. Comparison of different methods to extract the required coefficient of friction for level walking.

    Science.gov (United States)

    Chang, Wen-Ruey; Chang, Chien-Chi; Matz, Simon

    2012-01-01

    The required coefficient of friction (RCOF) is an important predictor for slip incidents. Despite the wide use of the RCOF there is no standardised method for identifying the RCOF from ground reaction forces. This article presents a comparison of the outcomes from seven different methods, derived from those reported in the literature, for identifying the RCOF from the same data. While commonly used methods are based on a normal force threshold, percentage of stance phase or time from heel contact, a newly introduced hybrid method is based on a combination of normal force, time and direction of increase in coefficient of friction. Although no major differences were found with these methods in more than half the strikes, significant differences were found in a significant portion of strikes. Potential problems with some of these methods were identified and discussed and they appear to be overcome by the hybrid method. No standard method exists for determining the required coefficient of friction (RCOF), an important predictor for slipping. In this study, RCOF values from a single data set, using various methods from the literature, differed considerably for a significant portion of strikes. A hybrid method may yield improved results.

  2. Paired comparisons analysis: an axiomatic approach to ranking methods

    NARCIS (Netherlands)

    Gonzalez-Diaz, J.; Hendrickx, Ruud; Lohmann, E.R.M.A.

    2014-01-01

    In this paper we present an axiomatic analysis of several ranking methods for general tournaments. We find that the ranking method obtained by applying maximum likelihood to the (Zermelo-)Bradley-Terry model, the most common method in statistics and psychology, is one of the ranking methods that

  3. Estimating recharge at yucca mountain, nevada, usa: comparison of methods

    International Nuclear Information System (INIS)

    Flint, A. L.; Flint, L. E.; Kwicklis, E. M.; Fabryka-Martin, J. T.; Bodvarsson, G. S.

    2001-01-01

    Obtaining values of net infiltration, groundwater travel time, and recharge is necessary at the Yucca Mountain site, Nevada, USA, in order to evaluate the expected performance of a potential repository as a containment system for high-level radioactive waste. However, the geologic complexities of this site, its low precipitation and net infiltration, with numerous mechanisms operating simultaneously to move water through the system, provide many challenges for the estimation of the spatial distribution of recharge. A variety of methods appropriate for and environments has been applied, including water-balance techniques, calculations using Darcy's law in the unsaturated zone, a soil-physics method applied to neutron-hole water-content data, inverse modeling of thermal profiles in boreholes extending through the thick unsaturated zone, chloride mass balance, atmospheric radionuclides, and empirical approaches. These methods indicate that near-surface infiltration rates at Yucca Mountain are highly variable in time and space, with local (point) values ranging from zero to several hundred millimeters per year. Spatially distributed net-infiltration values average 5 mm/year, with the highest values approaching 20 nun/year near Yucca Crest. Site-scale recharge estimates range from less than I to about 12 mm/year. These results have been incorporated into a site-scale model that has been calibrated using these data sets that reflect infiltration processes acting on highly variable temporal and spatial scales. The modeling study predicts highly non-uniform recharge at the water table, distributed significantly differently from the non-uniform infiltration pattern at the surface. [References: 57

  4. Estimating recharge at Yucca Mountain, Nevada, USA: Comparison of methods

    Science.gov (United States)

    Flint, A.L.; Flint, L.E.; Kwicklis, E.M.; Fabryka-Martin, J. T.; Bodvarsson, G.S.

    2002-01-01

    Obtaining values of net infiltration, groundwater travel time, and recharge is necessary at the Yucca Mountain site, Nevada, USA, in order to evaluate the expected performance of a potential repository as a containment system for high-level radioactive waste. However, the geologic complexities of this site, its low precipitation and net infiltration, with numerous mechanisms operating simultaneously to move water through the system, provide many challenges for the estimation of the spatial distribution of recharge. A variety of methods appropriate for arid environments has been applied, including water-balance techniques, calculations using Darcy's law in the unsaturated zone, a soil-physics method applied to neutron-hole water-content data, inverse modeling of thermal profiles in boreholes extending through the thick unsaturated zone, chloride mass balance, atmospheric radionuclides, and empirical approaches. These methods indicate that near-surface infiltration rates at Yucca Mountain are highly variable in time and space, with local (point) values ranging from zero to several hundred millimeters per year. Spatially distributed net-infiltration values average 5 mm/year, with the highest values approaching 20 mm/year near Yucca Crest. Site-scale recharge estimates range from less than 1 to about 12 mm/year. These results have been incorporated into a site-scale model that has been calibrated using these data sets that reflect infiltration processes acting on highly variable temporal and spatial scales. The modeling study predicts highly non-uniform recharge at the water table, distributed significantly differently from the non-uniform infiltration pattern at the surface.

  5. Particle fluxes above forests: Observations, methodological considerations and method comparisons

    International Nuclear Information System (INIS)

    Pryor, S.C.; Larsen, S.E.; Sorensen, L.L.; Barthelmie, R.J.

    2008-01-01

    This paper reports a study designed to test, evaluate and compare micro-meteorological methods for determining the particle number flux above forest canopies. Half-hour average particle number fluxes above a representative broad-leaved forest in Denmark derived using eddy covariance range from -7 x 10 7 m -2 s -1 (1st percentile) to 5 x 10 7 m -2 s -1 (99th percentile), and have a median value of -1.6 x 10 6 m -2 s -1 . The statistical uncertainties associated with the particle number flux estimates are larger than those for momentum fluxes and imply that in this data set approximately half of the particle number fluxes are not statistically different to zero. Particle number fluxes from relaxed eddy accumulation (REA) and eddy covariance are highly correlated and of almost identical magnitude. Flux estimates from the co-spectral and dissipation methods are also correlated with those from eddy covariance but exhibit higher absolute magnitude of fluxes. - Number fluxes of ultra-fine particles over a forest computed using four micro-meteorological techniques are highly correlated but vary in magnitude

  6. Comparison of thermoluminescence detection methods for irradiated spices

    International Nuclear Information System (INIS)

    Kawamura, Y.; Murayama, M.; Uchiyama, S.; Saito, Y.

    1996-01-01

    Thermoluminescence (TL) analysis has been shown to be one of the most applicable methods for the detection of γ-irradiated spices. This analysis was introduced as a detection technique for irradiated spices using the whole sample. It was then found that the origin of the TL response to be mineral dust adhering to the spices. TL measurements on separated minerals and the normalised TL measurement by re-irradiation was then established. This paper details investigations on TL measurements carried out using clean powdered spices stored for one year after being irradiated with doses of 1, 5, 10 and 30 kGy in order to clarify their applicable dose range, the effect of storage and mineral content. The effect of the mineral separation was also studied. (author)

  7. Comparison of different skin preservation methods with gamma irradiation.

    Science.gov (United States)

    Guerrero, Linda; Camacho, Bernardo

    2017-06-01

    Allografts are in constant demand, not only for burn victims, but also for all open wounds as "biological dressings". Tissue quality and security are two of the major concerns of Tissue Banks. There are limited studies published. There has been extensive discussion on the subject of preservation methods for cadaver skin. Most literature available comes from clinical reports. In this research, the authors compared 85% glycerolized non irradiated skin allografts with three glycerolized irradiated skin allografts (using different glycerol concentrations 50%, 70% and 85%). The evaluation of allograft quality was done by measuring physical and biological properties of such prepared human tissue grafts. In the histological structure evaluation changes were minimal and did not alter the skin structure. The clinical function of their behavior as temporal dressings was tested. They proved to have similar capabilities for improving granulating tissue and contributing to wound beds closure (Hickerson et al. (1994) [1]). Copyright © 2017 Elsevier Ltd and ISBI. All rights reserved.

  8. Comparison of different dose calculation methods for irregular photon fields

    International Nuclear Information System (INIS)

    Zakaria, G.A.; Schuette, W.

    2000-01-01

    In this work, 4 calculation methods (Wrede method, Clarskon method of sector integration, beam-zone method of Quast and pencil-beam method of Ahnesjoe) are introduced to calculate point doses in different irregular photon fields. The calculations cover a typical mantle field, an inverted Y-field and different blocked fields for 4 and 10 MV photon energies. The results are compared to those of measurements in a water phantom. The Clarkson and the pencil-beam method have been proved to be the methods of equal standard in relation to accuracy. Both of these methods are being distinguished by minimum deviations and applied in our clinical routine work. The Wrede and beam-zone methods deliver useful results to central beam and yet provide larger deviations in calculating points beyond the central axis. (orig.) [de

  9. Development and comparison in uncertainty assessment based Bayesian modularization method in hydrological modeling

    Science.gov (United States)

    Li, Lu; Xu, Chong-Yu; Engeland, Kolbjørn

    2013-04-01

    SummaryWith respect to model calibration, parameter estimation and analysis of uncertainty sources, various regression and probabilistic approaches are used in hydrological modeling. A family of Bayesian methods, which incorporates different sources of information into a single analysis through Bayes' theorem, is widely used for uncertainty assessment. However, none of these approaches can well treat the impact of high flows in hydrological modeling. This study proposes a Bayesian modularization uncertainty assessment approach in which the highest streamflow observations are treated as suspect information that should not influence the inference of the main bulk of the model parameters. This study includes a comprehensive comparison and evaluation of uncertainty assessments by our new Bayesian modularization method and standard Bayesian methods using the Metropolis-Hastings (MH) algorithm with the daily hydrological model WASMOD. Three likelihood functions were used in combination with standard Bayesian method: the AR(1) plus Normal model independent of time (Model 1), the AR(1) plus Normal model dependent on time (Model 2) and the AR(1) plus Multi-normal model (Model 3). The results reveal that the Bayesian modularization method provides the most accurate streamflow estimates measured by the Nash-Sutcliffe efficiency and provide the best in uncertainty estimates for low, medium and entire flows compared to standard Bayesian methods. The study thus provides a new approach for reducing the impact of high flows on the discharge uncertainty assessment of hydrological models via Bayesian method.

  10. A photon dominated region code comparison study

    NARCIS (Netherlands)

    Roellig, M.; Abel, N. P.; Bell, T.; Bensch, F.; Black, J.; Ferland, G. J.; Jonkheid, B.; Kamp, I.; Kaufman, M. J.; Le Bourlot, J.; Le Petit, F.; Meijerink, R.; Morata, O.; Ossenkopf, Volker; Roueff, E.; Shaw, G.; Spaans, M.; Sternberg, A.; Stutzki, J.; Thi, W.-F.; van Dishoeck, E. F.; van Hoof, P. A. M.; Viti, S.; Wolfire, M. G.

    Aims. We present a comparison between independent computer codes, modeling the physics and chemistry of interstellar photon dominated regions (PDRs). Our goal was to understand the mutual differences in the PDR codes and their effects on the physical and chemical structure of the model clouds, and

  11. Comparison of methods used to estimate coral cover in the Hawaiian Islands

    Directory of Open Access Journals (Sweden)

    Paul L. Jokiel

    2015-05-01

    Full Text Available Nine coral survey methods were compared at ten sites in various reef habitats with different levels of coral cover in Kāne‘ohe Bay, O’ahu, Hawaiʻi. Mean estimated coverage at the different sites ranged from less than 10% cover to greater than 90% cover. The methods evaluated include line transects, various visual and photographic belt transects, video transects and visual estimates. At each site 25 m transect lines were laid out and secured. Observers skilled in each method measured coral cover at each site. The time required to run each transect, time required to process data and time to record the results were documented. Cost of hardware and software for each method was also tabulated. Results of this investigation indicate that all of the methods used provide a good first estimate of coral cover on a reef. However, there were differences between the methods in detecting the number of coral species. For example, the classic “quadrat” method allows close examination of small and cryptic coral species that are not detected by other methods such as the “towboard” surveys. The time, effort and cost involved with each method varied widely, and the suitability of each method for answering particular research questions in various environments was evaluated. Results of this study support the finding of three other comparison method studies conducted at various geographic locations throughout the world. Thus, coral cover measured by different methods can be legitimately combined or compared in many situations. The success of a recent modeling effort based on coral cover data consisting of observations taken in Hawai‘i using the different methods supports this conclusion.

  12. Comparison of methods used to estimate coral cover in the Hawaiian Islands.

    Science.gov (United States)

    Jokiel, Paul L; Rodgers, Kuʻulei S; Brown, Eric K; Kenyon, Jean C; Aeby, Greta; Smith, William R; Farrell, Fred

    2015-01-01

    Nine coral survey methods were compared at ten sites in various reef habitats with different levels of coral cover in Kāne'ohe Bay, O'ahu, Hawai'i. Mean estimated coverage at the different sites ranged from less than 10% cover to greater than 90% cover. The methods evaluated include line transects, various visual and photographic belt transects, video transects and visual estimates. At each site 25 m transect lines were laid out and secured. Observers skilled in each method measured coral cover at each site. The time required to run each transect, time required to process data and time to record the results were documented. Cost of hardware and software for each method was also tabulated. Results of this investigation indicate that all of the methods used provide a good first estimate of coral cover on a reef. However, there were differences between the methods in detecting the number of coral species. For example, the classic "quadrat" method allows close examination of small and cryptic coral species that are not detected by other methods such as the "towboard" surveys. The time, effort and cost involved with each method varied widely, and the suitability of each method for answering particular research questions in various environments was evaluated. Results of this study support the finding of three other comparison method studies conducted at various geographic locations throughout the world. Thus, coral cover measured by different methods can be legitimately combined or compared in many situations. The success of a recent modeling effort based on coral cover data consisting of observations taken in Hawai'i using the different methods supports this conclusion.

  13. Preliminary comparison of different reduction methods of graphene ...

    Indian Academy of Sciences (India)

    diverse applications and developing a simple, green, and efficient method for the mass production of ... properties of graphene have driven the search to find methods ... Chemical reduction of GO sheets has been performed with ... efficient method for the mass production of graphene. 2. ... temperature was raised to 35.

  14. Qualitative Comparison of Contraction-Based Curve Skeletonization Methods

    NARCIS (Netherlands)

    Sobiecki, André; Yasan, Haluk C.; Jalba, Andrei C.; Telea, Alexandru C.

    2013-01-01

    In recent years, many new methods have been proposed for extracting curve skeletons of 3D shapes, using a mesh-contraction principle. However, it is still unclear how these methods perform with respect to each other, and with respect to earlier voxel-based skeletonization methods, from the viewpoint

  15. Comparison of three methods to assess individual skeletal maturity.

    Science.gov (United States)

    Pasciuti, Enzo; Franchi, Lorenzo; Baccetti, Tiziano; Milani, Silvano; Farronato, Giampietro

    2013-09-01

    The knowledge of facial growth and development is fundamental to determine the optimal timing for different treatment procedures in the growing patient. To analyze the reproducibility of three methods in assessing individual skeletal maturity, and to evaluate any degree of concordance among them. In all, 100 growing subjects were enrolled to test three methods: the hand-wrist, cervical vertebral maturation (CVM), and medial phalanges of the third finger method (MP3). Four operators determined the skeletal maturity of the subjects to evaluate the reproducibility of each method. After 30 days the operators repeated the analysis to assess the repeatability of each method. Finally, one operator examined all subjects' radiographs to detect any concordance among the three methods. The weighted kappa values for inter-operator variability were 0.94, 0.91, and 0.90, for the WRI, CVM, and MP3 methods, respectively. The weighted kappa values for intra-operator variability were 0.92, 0.91, and 0.92, for the WRI, CVM, and MP3 methods, respectively. The three methods revealed a high degree of repeatability and reproducibility. Complete agreement among the three methods was observed in 70% of the analyzed samples. The CVM method has the advantage of not necessitating an additional radiograph. The MP3 method is a simple and practical alternative as it requires only a standard dental x-ray device.

  16. Comparison of Kernel Equating and Item Response Theory Equating Methods

    Science.gov (United States)

    Meng, Yu

    2012-01-01

    The kernel method of test equating is a unified approach to test equating with some advantages over traditional equating methods. Therefore, it is important to evaluate in a comprehensive way the usefulness and appropriateness of the Kernel equating (KE) method, as well as its advantages and disadvantages compared with several popular item…

  17. A comparison of different methods for predicting coal devolatilisation kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Arenillas, A.; Rubiera, F.; Pevida, C.; Pis, J.J. [Instituto Nacional del Carbon, CSIC, Apartado 73, 33080 Oviedo (Spain)

    2001-04-01

    Knowledge of the coal devolatilisation rate is of great importance because it exerts a marked effect on the overall combustion behaviour. Different approaches can be used to obtain the kinetics of the complex devolatilisation process. The simplest are empirical and employ global kinetics, where the Arrhenius expression is used to correlate rates of mass loss with temperature. In this study a high volatile bituminous coal was devolatilised at four different heating rates in a thermogravimetric analyser (TG) linked to a mass spectrometer (MS). As a first approach, the Arrhenius kinetic parameters (k and A) were calculated from the experimental results, assuming a single step process. Another approach is the distributed-activation energy model, which is more complex due to the assumption that devolatilisation occurs through several first-order reactions, which occur simultaneously. Recent advances in the understanding of coal structure have led to more fundamental approaches for modelling devolatilisation behaviour, such as network models. These are based on a physico-chemical description of coal structure. In the present study the FG-DVC (Functional Group-Depolymerisation, Vaporisation and Crosslinking) computer code was used as the network model and the FG-DVC predicted evolution of volatile compounds was compared with the experimental results. In addition, the predicted rate of mass loss from the FG-DVC model was used to obtain a third devolatilisation kinetic approach. The three methods were compared and discussed, with the experimental results as a reference.

  18. Comparison of Various Methods for Isolation of Nocardia from Soil

    Directory of Open Access Journals (Sweden)

    Masoumeh Rasouli-Nasab

    2017-02-01

    Full Text Available Background The genus Nocardia is Gram-positive, aerobic filamentous bacilli and saprophytic micro-organisms that can be isolated from freshwater, salt water, dust and decaying vegetation especially the soil. This study aimed to investigate the several media for to determine a suitable culture media with the ability to better for the isolation of Nocardia from soil. Methods In this study, 400 soil samples were collected from different areas from Iran. The soil samples were then cultured on the four culture media such as Humic acid vitamin B agar, Paraffin agar, Sabouraud dextrose agar supplemented whit cycloheximide and carbon-free broth containing paraffin rods and incubated at 35°C. All of culture media investigated every 3 days for a month. Colonies suspicious to Nocardia were stained with Gram-stain, acid-fast and partially acid-fast and evaluated for resistance to lysozyme. Results From 400 soil samples, the number of 62, 10, 28 and 19 strains of Nocardia were isolated by paraffin rods, Humic Acid Vitamin B agar, Paraffin agar and Sabouraud dextrose agar whit cycloheximide, respectively. Most Nocardia strains were isolated using paraffin bait technique. Conclusions Isolation of Nocardia spp. is enhanced by using the paraffin baiting technique that relies on the selective ability of this micro-organism to metabolize paraffin.

  19. A new ART iterative method and a comparison of performance among various ART methods

    International Nuclear Information System (INIS)

    Tan, Yufeng; Sato, Shunsuke

    1993-01-01

    Many algebraic reconstruction techniques (ART) image reconstruction algorithms, for instance, simultaneous iterative reconstruction technique (SIRT), the relaxation method and multiplicative ART (MART), have been proposed and their convergent properties have been studied. SIRT and the underrelaxed relaxation method converge to the least-squares solution, but the convergent speeds are very slow. The Kaczmarz method converges very quickly, but the reconstructed images contain a lot of noise. The comparative studies between these algorithms have been done by Gilbert and others, but are not adequate. In this paper, we (1) propose a new method which is a modified Kaczmarz method and prove its convergence property, (2) study performance of 7 algorithms including the one proposed here by computer simulation for 3 kinds of typical phantoms. The method proposed here does not give the least-square solution, but the root mean square errors of its reconstructed images decrease very quickly after few interations. The result shows that the method proposed here gives a better reconstructed image. (author)

  20. Comparison of Chemical Extraction Methods for Determination of Soil Potassium in Different Soil Types

    Science.gov (United States)

    Zebec, V.; Rastija, D.; Lončarić, Z.; Bensa, A.; Popović, B.; Ivezić, V.

    2017-12-01

    Determining potassium supply of soil plays an important role in intensive crop production, since it is the basis for balancing nutrients and issuing fertilizer recommendations for achieving high and stable yields within economic feasibility. The aim of this study was to compare the different extraction methods of soil potassium from arable horizon of different types of soils with ammonium lactate method (KAL), which is frequently used as analytical method for determining the accessibility of nutrients and it is a common method used for issuing fertilizer recommendations in many Europe countries. In addition to the ammonium lactate method (KAL, pH 3.75), potassium was extracted with ammonium acetate (KAA, pH 7), ammonium acetate ethylenediaminetetraacetic acid (KAAEDTA, pH 4.6), Bray (KBRAY, pH 2.6) and with barium chloride (K_{BaCl_2 }, pH 8.1). The analyzed soils were extremely heterogeneous with a wide range of determined values. Soil pH reaction ( {pH_{H_2 O} } ) ranged from 4.77 to 8.75, organic matter content ranged from 1.87 to 4.94% and clay content from 8.03 to 37.07%. In relation to KAL method as the standard method, K_{BaCl_2 } method extracts 12.9% more on average of soil potassium, while in relation to standard method, on average KAA extracts 5.3%, KAAEDTA 10.3%, and KBRAY 27.5% less of potassium. Comparison of analyzed extraction methods of potassium from the soil is of high precision, and most reliable comparison was KAL method with KAAEDTA, followed by a: KAA, K_{BaCl_2 } and KBRAY method. Extremely significant statistical correlation between different extractive methods for determining potassium in the soil indicates that any of the methods can be used to accurately predict the concentration of potassium in the soil, and that carried out research can be used to create prediction model for concentration of potassium based on different methods of extraction.

  1. Comparison of three control methods for an autonomous vehicle

    Science.gov (United States)

    Deshpande, Anup; Mathur, Kovid; Hall, Ernest

    2010-01-01

    The desirability and challenge of developing a completely autonomous vehicle and the rising need for more efficient use of energy by automobiles motivate this research- a study for an optimum solution to computer control of energy efficient vehicles. The purpose of this paper is to compare three control methods - mechanical, hydraulic and electric that have been used to convert an experimental all terrain vehicle to drive by wire which would eventually act as a test bed for conducting research on various technologies for autonomous operation. Computer control of basic operations in a vehicle namely steering, braking and speed control have been implemented and will be described in this paper. The output from a 3 axis motion controller is used for this purpose. The motion controller is interfaced with a software program using WSDK (Windows Servo Design Kit) as an intermediate tuning layer for tuning and parameter settings in autonomous operation. The software program is developed in C++. The voltage signal sent to the motion controller can be varied through the control program for desired results in controlling the steering motor, activating the hydraulic brakes and varying the vehicle's speed. The vehicle has been tested for its basic functionality which includes testing of street legal operations and also a 1000 mile test while running in a hybrid mode. The vehicle has also been tested for control when it is interfaced with devices such as a keyboard, joystick and sensors under full autonomous operation. The vehicle is currently being tested in various safety studies and is being used as a test bed for experiments in control courses and research studies. The significance of this research is in providing a greater understanding of conventional driving controls and the possibility of improving automobile safety by removing human error in control of a motor vehicle.

  2. Comparison of the surface friction model with the time-dependent Hartree-Fock method

    International Nuclear Information System (INIS)

    Froebrich, P.

    1984-01-01

    A comparison is made between the classical phenomenological surface friction model and a time-dependent Hartree-Fock study by Dhar for the system 208 Pb+ 74 Ge at E/sub lab/(Pb) = 1600 MeV. The general trends for energy loss, mean values for charge and mass, interaction times and energy-angle correlations turn out to be fairly similar in both methods. However, contrary to Dhar, the events close to capture are interpreted as normal deep-inelastic, i.e., not as fast fission processes

  3. From a tree to a stand in Finnish boreal forests: biomass estimation and comparison of methods

    OpenAIRE

    Liu, Chunjiang

    2009-01-01

    There is an increasing need to compare the results obtained with different methods of estimation of tree biomass in order to reduce the uncertainty in the assessment of forest biomass carbon. In this study, tree biomass was investigated in a 30-year-old Scots pine (Pinus sylvestris) (Young-Stand) and a 130-year-old mixed Norway spruce (Picea abies)-Scots pine stand (Mature-Stand) located in southern Finland (61º50' N, 24º22' E). In particular, a comparison of the results of different estimati...

  4. Inconsistency between direct and indirect comparisons of competing interventions: meta-epidemiological study.

    Science.gov (United States)

    Song, Fujian; Xiong, Tengbin; Parekh-Bhurke, Sheetal; Loke, Yoon K; Sutton, Alex J; Eastwood, Alison J; Holland, Richard; Chen, Yen-Fu; Glenny, Anne-Marie; Deeks, Jonathan J; Altman, Doug G

    2011-08-16

    To investigate the agreement between direct and indirect comparisons of competing healthcare interventions. Meta-epidemiological study based on sample of meta-analyses of randomised controlled trials. Data sources Cochrane Database of Systematic Reviews and PubMed. Inclusion criteria Systematic reviews that provided sufficient data for both direct comparison and independent indirect comparisons of two interventions on the basis of a common comparator and in which the odds ratio could be used as the outcome statistic. Inconsistency measured by the difference in the log odds ratio between the direct and indirect methods. The study included 112 independent trial networks (including 1552 trials with 478,775 patients in total) that allowed both direct and indirect comparison of two interventions. Indirect comparison had already been explicitly done in only 13 of the 85 Cochrane reviews included. The inconsistency between the direct and indirect comparison was statistically significant in 16 cases (14%, 95% confidence interval 9% to 22%). The statistically significant inconsistency was associated with fewer trials, subjectively assessed outcomes, and statistically significant effects of treatment in either direct or indirect comparisons. Owing to considerable inconsistency, many (14/39) of the statistically significant effects by direct comparison became non-significant when the direct and indirect estimates were combined. Significant inconsistency between direct and indirect comparisons may be more prevalent than previously observed. Direct and indirect estimates should be combined in mixed treatment comparisons only after adequate assessment of the consistency of the evidence.

  5. A comparison of four gravimetric fine particle sampling methods.

    Science.gov (United States)

    Yanosky, J D; MacIntosh, D L

    2001-06-01

    A study was conducted to compare four gravimetric methods of measuring fine particle (PM2.5) concentrations in air: the BGI, Inc. PQ200 Federal Reference Method PM2.5 (FRM) sampler; the Harvard-Marple Impactor (HI); the BGI, Inc. GK2.05 KTL Respirable/Thoracic Cyclone (KTL); and the AirMetrics MiniVol (MiniVol). Pairs of FRM, HI, and KTL samplers and one MiniVol sampler were collocated and 24-hr integrated PM2.5 samples were collected on 21 days from January 6 through April 9, 2000. The mean and standard deviation of PM2.5 levels from the FRM samplers were 13.6 and 6.8 microg/m3, respectively. Significant systematic bias was found between mean concentrations from the FRM and the MiniVol (1.14 microg/m3, p = 0.0007), the HI and the MiniVol (0.85 microg/m3, p = 0.0048), and the KTL and the MiniVol (1.23 microg/m3, p = 0.0078) according to paired t test analyses. Linear regression on all pairwise combinations of the sampler types was used to evaluate measurements made by the samplers. None of the regression intercepts was significantly different from 0, and only two of the regression slopes were significantly different from 1, that for the FRM and the MiniVol [beta1 = 0.91, 95% CI (0.83-0.99)] and that for the KTL and the MiniVol [beta1 = 0.88, 95% CI (0.78-0.98)]. Regression R2 terms were 0.96 or greater between all pairs of samplers, and regression root mean square error terms (RMSE) were 1.65 microg/m3 or less. These results suggest that the MiniVol will underestimate measurements made by the FRM, the HI, and the KTL by an amount proportional to PM2.5 concentration. Nonetheless, these results indicate that all of the sampler types are comparable if approximately 10% variation on the mean levels and on individual measurement levels is considered acceptable and the actual concentration is within the range of this study (5-35 microg/m3).

  6. Comparisons of ratchetting analysis methods using RCC-M, RCC-MR and ASME codes

    International Nuclear Information System (INIS)

    Yang Yu; Cabrillat, M.T.

    2005-01-01

    The present paper compares the simplified ratcheting analysis methods used in RCC-M, RCC-MR and ASME with some examples. Firstly, comparisons of the methods in RCC-M and efficiency diagram in RCC-MR are investigated. A special method is used to describe these two methods with curves in one coordinate, and the different conservation is demonstrated. RCC-M method is also be interpreted by SR (second ratio) and v (efficiency index) which is used in RCC-MR. Hence, we can easily compare the previous two methods by defining SR as abscissa and v as ordinate and plotting two curves of them. Secondly, comparisons of the efficiency curve in RCC-MR and methods in ASME-NH APPENDIX T are investigated, with significant creep. At last, two practical evaluations are performed to show the comparisons of aforementioned methods. (authors)

  7. A comparison of Ki-67 counting methods in luminal Breast Cancer: The Average Method vs. the Hot Spot Method.

    Directory of Open Access Journals (Sweden)

    Min Hye Jang

    Full Text Available In spite of the usefulness of the Ki-67 labeling index (LI as a prognostic and predictive marker in breast cancer, its clinical application remains limited due to variability in its measurement and the absence of a standard method of interpretation. This study was designed to compare the two methods of assessing Ki-67 LI: the average method vs. the hot spot method and thus to determine which method is more appropriate in predicting prognosis of luminal/HER2-negative breast cancers. Ki-67 LIs were calculated by direct counting of three representative areas of 493 luminal/HER2-negative breast cancers using the two methods. We calculated the differences in the Ki-67 LIs (ΔKi-67 between the two methods and the ratio of the Ki-67 LIs (H/A ratio of the two methods. In addition, we compared the performance of the Ki-67 LIs obtained by the two methods as prognostic markers. ΔKi-67 ranged from 0.01% to 33.3% and the H/A ratio ranged from 1.0 to 2.6. Based on the receiver operating characteristic curve method, the predictive powers of the KI-67 LI measured by the two methods were similar (Area under curve: hot spot method, 0.711; average method, 0.700. In multivariate analysis, high Ki-67 LI based on either method was an independent poor prognostic factor, along with high T stage and node metastasis. However, in repeated counts, the hot spot method did not consistently classify tumors into high vs. low Ki-67 LI groups. In conclusion, both the average and hot spot method of evaluating Ki-67 LI have good predictive performances for tumor recurrence in luminal/HER2-negative breast cancers. However, we recommend using the average method for the present because of its greater reproducibility.

  8. A comparison of Ki-67 counting methods in luminal Breast Cancer: The Average Method vs. the Hot Spot Method.

    Science.gov (United States)

    Jang, Min Hye; Kim, Hyun Jung; Chung, Yul Ri; Lee, Yangkyu; Park, So Yeon

    2017-01-01

    In spite of the usefulness of the Ki-67 labeling index (LI) as a prognostic and predictive marker in breast cancer, its clinical application remains limited due to variability in its measurement and the absence of a standard method of interpretation. This study was designed to compare the two methods of assessing Ki-67 LI: the average method vs. the hot spot method and thus to determine which method is more appropriate in predicting prognosis of luminal/HER2-negative breast cancers. Ki-67 LIs were calculated by direct counting of three representative areas of 493 luminal/HER2-negative breast cancers using the two methods. We calculated the differences in the Ki-67 LIs (ΔKi-67) between the two methods and the ratio of the Ki-67 LIs (H/A ratio) of the two methods. In addition, we compared the performance of the Ki-67 LIs obtained by the two methods as prognostic markers. ΔKi-67 ranged from 0.01% to 33.3% and the H/A ratio ranged from 1.0 to 2.6. Based on the receiver operating characteristic curve method, the predictive powers of the KI-67 LI measured by the two methods were similar (Area under curve: hot spot method, 0.711; average method, 0.700). In multivariate analysis, high Ki-67 LI based on either method was an independent poor prognostic factor, along with high T stage and node metastasis. However, in repeated counts, the hot spot method did not consistently classify tumors into high vs. low Ki-67 LI groups. In conclusion, both the average and hot spot method of evaluating Ki-67 LI have good predictive performances for tumor recurrence in luminal/HER2-negative breast cancers. However, we recommend using the average method for the present because of its greater reproducibility.

  9. Comparison between two methods for resin removing after bracket debonding

    Directory of Open Access Journals (Sweden)

    Rodrigo De Marchi

    2012-12-01

    Full Text Available OBJECTIVE: The aim of this study was to assess - using scanning electron microscopy (SEM - the effectiveness of two abrasive discs, one made from silicon and one from aluminum oxide, in removing adhesive remnants (AR after debonding orthodontic brackets. METHODS: Ten randomly selected bovine teeth were used, i.e., 2 in the control group, and the other 8 divided into two groups, which had orthodontic brackets bonded to their surface with Concise Orthodontic Adhesive (3M. The following methods were employed - in one single step - to remove AR after debracketing: Group A, Optimize discs (TDV and Group B, Onegloss discs (Shofu, used at low speed. After removing the AR with the aforementioned methods, the teeth were prepared to undergo SEM analysis, and photographs were taken of the enamel surface with 50x magnification. Six examiners evaluated the photographs applying the Zachrisson and Årtun enamel surface index (ESI system (1979. RESULTS: Group A exhibited minor scratches on the enamel surface as well as some AR in some of the photographs, while Group B showed a smoother surface, little or no AR and some abrasion marks in the photographs. No statistically significant differences were found between the two methods and the control group. CONCLUSIONS: The two abrasive discs were effective in removing the AR after bracket debonding in one single step.OBJETIVO: o objetivo deste trabalho foi avaliar, por microscopia eletrônica de varredura, a eficácia de dois discos abrasivos de silicone e óxido de alumínio para a remoção da resina remanescente após a descolagem de braquetes ortodônticos. MÉTODOS: foram utilizados 10 dentes bovinos selecionados aleatoriamente, sendo 2 para o grupo controle e os demais divididos em dois grupos, os quais receberam colagem de braquetes ortodônticos com resina ortodôntica Concise (3M. Os métodos de remoção da resina após a descolagem dos acessórios ortodônticos em apenas uma etapa foram: Grupo A - disco

  10. Comparison of 3 in vivo methods for assessment of alcohol-based hand rubs.

    Science.gov (United States)

    Edmonds-Wilson, Sarah; Campbell, Esther; Fox, Kyle; Macinga, David

    2015-05-01

    Alcohol-based hand rubs (ABHRs) are the primary method of hand hygiene in health-care settings. ICPs increasingly are assessing ABHR product efficacy data as improved products and test methods are developed. As a result, ICPs need better tools and recommendations for how to assess and compare ABHRs. Two ABHRs (70% ethanol) were tested according to 3 in vivo methods approved by ASTM International: E1174, E2755, and E2784. Log10 reductions were measured after a single test product use and after 10 consecutive uses at an application volume of 2 mL. The test method used had a significant influence on ABHR efficacy; however, in this study the test product (gel or foam) did not significantly influence efficacy. In addition, for all test methods, log10 reductions obtained after a single application were not predictive of results after 10 applications. Choice of test method can significantly influence efficacy results. Therefore, when assessing antimicrobial efficacy data of hand hygiene products, ICPs should pay close attention to the test method used, and ensure that product comparisons are made head to head in the same study using the same test methodology. Copyright © 2015 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  11. Accessibility of long-term family planning methods: a comparison study between Output Based Approach (OBA) clients verses non-OBA clients in the voucher supported facilities in Kenya.

    Science.gov (United States)

    Oyugi, Boniface; Kioko, Urbanus; Kaboro, Stephen Mbugua; Gikonyo, Shadrack; Okumu, Clarice; Ogola-Munene, Sarah; Kalsi, Shaminder; Thiani, Simon; Korir, Julius; Odundo, Paul; Baltazaar, Billy; Ranji, Moses; Muraguri, Nicholas; Nzioka, Charles

    2017-03-27

    The study seeks to evaluate the difference in access of long-term family planning (LTFP) methods among the output based approach (OBA) and non-OBA clients within the OBA facility. The study utilises a quasi experimental design. A two tailed unpaired t-test with unequal variance is used to test for the significance variation in the mean access. The difference in difference (DiD) estimates of program effect on long term family planning methods is done to estimate the causal effect by exploiting the group level difference on two or more dimensions. The study also uses a linear regression model to evaluate the predictors of choice of long-term family planning methods. Data was analysed using SPSS version 17. All the methods (Bilateral tubal ligation-BTL, Vasectomy, intrauterine contraceptive device -IUCD, Implants, and Total or combined long-term family planning methods -LTFP) showed a statistical significant difference in the mean utilization between OBA versus non-OBA clients. The difference in difference estimates reveal that the difference in access between OBA and non OBA clients can significantly be attributed to the implementation of the OBA program for intrauterine contraceptive device (p = 0.002), Implants (p = 0.004), and total or combined long-term family planning methods (p = 0.001). The county of residence is a significant determinant of access to all long-term family planning methods except vasectomy and the year of registration is a significant determinant of access especially for implants and total or combined long-term family planning methods. The management level and facility type does not play a role in determining the type of long-term family planning method preferred; however, non-governmental organisations (NGOs) as management level influences the choice of all methods (Bilateral tubal ligation, intrauterine contraceptive device, Implants, and combined methods) except vasectomy. The adjusted R 2 value, representing the percentage of

  12. Comparison of PCR method with the culture method for identification of gonococci from endocervical swabs

    Directory of Open Access Journals (Sweden)

    Alam A

    2002-01-01

    Full Text Available Gonococcal infection remains still a major cause of morbidity among sexually active individuals. Diagnosis of the infection in a female case is more difficult than that in a male. This was a prospective study among 269 female commercial sex workers (CSWs to screen them for gonococcal infection, comparing the rapid method of identification of gonococci by polymerase chain reaction (PCR with the selective culture method. A total of 92 (34.2% CSWs were identified positive for Neisseria gonorrhoeae by combination of the two methods. The PCR method identified 87 of the specimens to harbour cppB gene of N. gonorrhoeae, whereas culture method identified 83 specimens showing colonies of gonococci. Taking into consideration of the total positive cases (92, the PCR method showed a sensitivity of 94.57%, whereas sensitivity of culture method was 90.22%. The selective culture method appears to be the most applicable in the identification of gonococci from clinical specimens, particularly in the less resourceful countries like Bangladesh.

  13. Clustering Scientific Publications Based on Citation Relations: A Systematic Comparison of Different Methods.

    Science.gov (United States)

    Šubelj, Lovro; van Eck, Nees Jan; Waltman, Ludo

    2016-01-01

    Clustering methods are applied regularly in the bibliometric literature to identify research areas or scientific fields. These methods are for instance used to group publications into clusters based on their relations in a citation network. In the network science literature, many clustering methods, often referred to as graph partitioning or community detection techniques, have been developed. Focusing on the problem of clustering the publications in a citation network, we present a systematic comparison of the performance of a large number of these clustering methods. Using a number of different citation networks, some of them relatively small and others very large, we extensively study the statistical properties of the results provided by different methods. In addition, we also carry out an expert-based assessment of the results produced by different methods. The expert-based assessment focuses on publications in the field of scientometrics. Our findings seem to indicate that there is a trade-off between different properties that may be considered desirable for a good clustering of publications. Overall, map equation methods appear to perform best in our analysis, suggesting that these methods deserve more attention from the bibliometric community.

  14. Clustering Scientific Publications Based on Citation Relations: A Systematic Comparison of Different Methods

    Science.gov (United States)

    Šubelj, Lovro; van Eck, Nees Jan; Waltman, Ludo

    2016-01-01

    Clustering methods are applied regularly in the bibliometric literature to identify research areas or scientific fields. These methods are for instance used to group publications into clusters based on their relations in a citation network. In the network science literature, many clustering methods, often referred to as graph partitioning or community detection techniques, have been developed. Focusing on the problem of clustering the publications in a citation network, we present a systematic comparison of the performance of a large number of these clustering methods. Using a number of different citation networks, some of them relatively small and others very large, we extensively study the statistical properties of the results provided by different methods. In addition, we also carry out an expert-based assessment of the results produced by different methods. The expert-based assessment focuses on publications in the field of scientometrics. Our findings seem to indicate that there is a trade-off between different properties that may be considered desirable for a good clustering of publications. Overall, map equation methods appear to perform best in our analysis, suggesting that these methods deserve more attention from the bibliometric community. PMID:27124610

  15. A Comparison between the Effect of Cooperative Learning Teaching Method and Lecture Teaching Method on Students' Learning and Satisfaction Level

    Science.gov (United States)

    Mohammadjani, Farzad; Tonkaboni, Forouzan

    2015-01-01

    The aim of the present research is to investigate a comparison between the effect of cooperative learning teaching method and lecture teaching method on students' learning and satisfaction level. The research population consisted of all the fourth grade elementary school students of educational district 4 in Shiraz. The statistical population…

  16. A statistical comparison of accelerated concrete testing methods

    OpenAIRE

    Denny Meyer

    1997-01-01

    Accelerated curing results, obtained after only 24 hours, are used to predict the 28 day strength of concrete. Various accelerated curing methods are available. Two of these methods are compared in relation to the accuracy of their predictions and the stability of the relationship between their 24 hour and 28 day concrete strength. The results suggest that Warm Water accelerated curing is preferable to Hot Water accelerated curing of concrete. In addition, some other methods for improving the...

  17. Comparison of microstickies measurement methods. Part II, Results and discussion

    Science.gov (United States)

    Mahendra R. Doshi; Angeles Blanco; Carlos Negro; Concepcion Monte; Gilles M. Dorris; Carlos C. Castro; Axel Hamann; R. Daniel Haynes; Carl Houtman; Karen Scallon; Hans-Joachim Putz; Hans Johansson; R. A. Venditti; K. Copeland; H.-M. Chang

    2003-01-01

    In part I of the article we discussed sample preparation procedure and described various methods used for the measurement of microstickies. Some of the important features of different methods are highlighted in Table 1. Temperatures used in the measurement methods vary from room temperature in some cases, 45 °C to 65 °C in other cases. Sample size ranges from as low as...

  18. Comparison of Heuristic Methods Applied for Optimal Operation of Water Resources

    Directory of Open Access Journals (Sweden)

    Alireza Borhani Dariane

    2009-01-01

    Full Text Available Water resources optimization problems are usually complex and hard to solve using the ordinary optimization methods, or they are at least  not economically efficient. A great number of studies have been conducted in quest of suitable methods capable of handling such problems. In recent years, some new heuristic methods such as genetic and ant algorithms have been introduced in systems engineering. Preliminary applications of these methods in water resources problems have shown that some of them are powerful tools, capable of solving complex problems. In this paper, the application of such heuristic methods as Genetic Algorithm (GA and Ant Colony Optimization (ACO have been studied for optimizing reservoir operation. The Dez Dam reservoir inIranwas chosen for a case study. The methods were applied and compared using short-term (one year and long-term models. Comparison of the results showed that GA outperforms both DP and ACO in finding true global optimum solutions and operating rules.

  19. External laryngeal injuries in children--comparison of diagnostic methods.

    Science.gov (United States)

    Zawadzka-Glos, L; Jakubowska, A; Frackiewicz, M; Brzewski, M

    2013-09-01

    The injuries of the larynx constitute around 1% of all injuries. The great majority of the injuries of the larynx happens during playing. The effects of these injuries may appear insignificant however, not always the direct clinical symptoms correlate with the degree of respiratory tract failure. The symptoms of laryngeal injuries depend on the extension and strength of the trauma and always relate to impair patency of respiratory tract. The aim of the study is to compare two diagnostic methods: laryngoscopy and ultrasonography in evaluation of laryngeal injuries in children. In the Department of Pediatric Otolaryngology, Medical University of Warsaw, in the period between 2004 and 2010 there were hospitalised 15 children with external injury of the larynx. From among 15 hospitalized children, 7 were qualified as not serious trauma and were treated preservatively and the other 8 as sever trauma. The mechanism of traumas was diverse. Dyspnea was a predominating symptom, the others included hoarsness, change in voice quality, even aphonia, pain while speaking and swallowing, cough and hemoptysis. Direct laryngoscopy is a standard in diagnostics of the injuries of the larynx. Ultrasonography of the larynx is recommended in every case of laryngeal injury as an additional non-invasive complementary diagnostic examination. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  20. Mathematical methods for quantification and comparison of dissolution testing data.

    Science.gov (United States)

    Vranić, Edina; Mehmedagić, Aida; Hadzović, Sabira

    2002-12-01

    In recent years, drug release/dissolution from solid dosage forms has been the subject of intense and profitable scientific developments. Whenever a new solid dosage form is developed or produced, it is necessary to ensure that drug dissolution occurs in an appropriate manner. The pharmaceutical industry and the registration authorities do focus, nowadays, on drug dissolution studies. The quantitative analysis of the values obtained in dissolution/release tests is easier when mathematical formulas that express the dissolution results as a function of some of the dosage forms characteristics are used. This work discusses the analysis of data obtained for dissolution profiles under different media pH conditions using mathematical methods of analysis described by Moore and Flanner. These authors have described difference factor (f1) and similarity factor (f2), which can be used to characterise drug dissolution/release profiles. In this work we have used these formulas for evaluation of dissolution profiles of the conventional tablets in different pH of dissolution medium (range of physiological variations).

  1. Comparison of electrical conductivity calculation methods for natural waters

    Science.gov (United States)

    McCleskey, R. Blaine; Nordstrom, D. Kirk; Ryan, Joseph N.

    2012-01-01

    The capability of eleven methods to calculate the electrical conductivity of a wide range of natural waters from their chemical composition was investigated. A brief summary of each method is presented including equations to calculate the conductivities of individual ions, the ions incorporated, and the method's limitations. The ability of each method to reliably predict the conductivity depends on the ions included, effective accounting of ion pairing, and the accuracy of the equation used to estimate the ionic conductivities. The performances of the methods were evaluated by calculating the conductivity of 33 environmentally important electrolyte solutions, 41 U.S. Geological Survey standard reference water samples, and 1593 natural water samples. The natural waters tested include acid mine waters, geothermal waters, seawater, dilute mountain waters, and river water impacted by municipal waste water. The three most recent conductivity methods predict the conductivity of natural waters better than other methods. Two of the recent methods can be used to reliably calculate the conductivity for samples with pH values greater than about 3 and temperatures between 0 and 40°C. One method is applicable to a variety of natural water types with a range of pH from 1 to 10, temperature from 0 to 95°C, and ionic strength up to 1 m.

  2. Soil structure interaction calculations: a comparison of methods

    International Nuclear Information System (INIS)

    Wight, L.; Zaslawsky, M.

    1976-01-01

    Two approaches for calculating soil structure interaction (SSI) are compared: finite element and lumped mass. Results indicate that the calculations with the lumped mass method are generally conservative compared to those obtained by the finite element method. They also suggest that a closer agreement between the two sets of calculations is possible, depending on the use of frequency-dependent soil springs and dashpots in the lumped mass calculations. There is a total lack of suitable guidelines for implementing the lumped mass method of calculating SSI, which leads to the conclusion that the finite element method is generally superior for calculative purposes

  3. Soil structure interaction calculations: a comparison of methods

    Energy Technology Data Exchange (ETDEWEB)

    Wight, L.; Zaslawsky, M.

    1976-07-22

    Two approaches for calculating soil structure interaction (SSI) are compared: finite element and lumped mass. Results indicate that the calculations with the lumped mass method are generally conservative compared to those obtained by the finite element method. They also suggest that a closer agreement between the two sets of calculations is possible, depending on the use of frequency-dependent soil springs and dashpots in the lumped mass calculations. There is a total lack of suitable guidelines for implementing the lumped mass method of calculating SSI, which leads to the conclusion that the finite element method is generally superior for calculative purposes.

  4. A Comparison of Three Methods for the Analysis of Skin Flap Viability: Reliability and Validity.

    Science.gov (United States)

    Tim, Carla Roberta; Martignago, Cintia Cristina Santi; da Silva, Viviane Ribeiro; Dos Santos, Estefany Camila Bonfim; Vieira, Fabiana Nascimento; Parizotto, Nivaldo Antonio; Liebano, Richard Eloin

    2018-05-01

    Objective: Technological advances have provided new alternatives to the analysis of skin flap viability in animal models; however, the interrater validity and reliability of these techniques have yet to be analyzed. The present study aimed to evaluate the interrater validity and reliability of three different methods: weight of paper template (WPT), paper template area (PTA), and photographic analysis. Approach: Sixteen male Wistar rats had their cranially based dorsal skin flap elevated. On the seventh postoperative day, the viable tissue area and the necrotic area of the skin flap were recorded using the paper template method and photo image. The evaluation of the percentage of viable tissue was performed using three methods, simultaneously and independently by two raters. The analysis of interrater reliability and viability was performed using the intraclass correlation coefficient and Bland Altman Plot Analysis was used to visualize the presence or absence of systematic bias in the evaluations of data validity. Results: The results showed that interrater reliability for WPT, measurement of PTA, and photographic analysis were 0.995, 0.990, and 0.982, respectively. For data validity, a correlation >0.90 was observed for all comparisons made between the three methods. In addition, Bland Altman Plot Analysis showed agreement between the comparisons of the methods and the presence of systematic bias was not observed. Innovation: Digital methods are an excellent choice for assessing skin flap viability; moreover, they make data use and storage easier. Conclusion: Independently from the method used, the interrater reliability and validity proved to be excellent for the analysis of skin flaps' viability.

  5. Comparison of three noninvasive methods for hemoglobin screening of blood donors.

    Science.gov (United States)

    Ardin, Sergey; Störmer, Melanie; Radojska, Stela; Oustianskaia, Larissa; Hahn, Moritz; Gathof, Birgit S

    2015-02-01

    To prevent phlebotomy of anemic individuals and to ensure hemoglobin (Hb) content of the blood units, Hb screening of blood donors before donation is essential. Hb values are mostly evaluated by measurement of capillary blood obtained from fingerstick. Rapid noninvasive methods have recently become available and may be preferred by donors and staff. The aim of this study was to evaluate for the first time all different noninvasive methods for Hb screening. Blood donors were screened for Hb levels in three different trials using three different noninvasive methods (Haemospect [MBR Optical Systems GmbH & Co. KG], NBM 200 [LMB Technology GmbH], Pronto-7 [Masimo Europe Ltd]) in comparison to the established fingerstick method (CompoLab Hb [Fresenius Kabi GmbH]) and to levels obtained from venous samples on a cell counter (Sysmex [Sysmex Europe GmbH]) as reference. The usability of the noninvasive methods was assessed with an especially developed survey. Technical failures occurred by using the Pronto-7 due to nail polish, skin color, or ambient light. The NBM 200 also showed a high sensitivity to ambient light and noticeably lower Hb levels for women than obtained from the Sysmex. The statistical analysis showed the following bias and standard deviation of differences of all methods in comparison to the venous results: Haemospect, -0.22 ± 1.24; NBM, 200 -0.12 ± 1.14; Pronto-7, -0.50 ± 0.99; and CompoLab Hb, -0.53 ± 0.81. Noninvasive Hb tests represent an attractive alternative by eliminating pain and reducing risks of blood contamination. The main problem for generating reliable results seems to be preanalytical variability in sampling. Despite the sensitivity to environmental stress, all methods are suitable for Hb measurement. © 2014 AABB.

  6. Evaluation and comparison of mammalian subcellular localization prediction methods

    Directory of Open Access Journals (Sweden)

    Fink J Lynn

    2006-12-01

    Full Text Available Abstract Background Determination of the subcellular location of a protein is essential to understanding its biochemical function. This information can provide insight into the function of hypothetical or novel proteins. These data are difficult to obtain experimentally but have become especially important since many whole genome sequencing projects have been finished and many resulting protein sequences are still lacking detailed functional information. In order to address this paucity of data, many computational prediction methods have been developed. However, these methods have varying levels of accuracy and perform differently based on the sequences that are presented to the underlying algorithm. It is therefore useful to compare these methods and monitor their performance. Results In order to perform a comprehensive survey of prediction methods, we selected only methods that accepted large batches of protein sequences, were publicly available, and were able to predict localization to at least nine of the major subcellular locations (nucleus, cytosol, mitochondrion, extracellular region, plasma membrane, Golgi apparatus, endoplasmic reticulum (ER, peroxisome, and lysosome. The selected methods were CELLO, MultiLoc, Proteome Analyst, pTarget and WoLF PSORT. These methods were evaluated using 3763 mouse proteins from SwissProt that represent the source of the training sets used in development of the individual methods. In addition, an independent evaluation set of 2145 mouse proteins from LOCATE with a bias towards the subcellular localization underrepresented in SwissProt was used. The sensitivity and specificity were calculated for each method and compared to a theoretical value based on what might be observed by random chance. Conclusion No individual method had a sufficient level of sensitivity across both evaluation sets that would enable reliable application to hypothetical proteins. All methods showed lower performance on the LOCATE

  7. Comparison contemporary methods of regeneration sodium-cationic filters

    Science.gov (United States)

    Burakov, I. A.; Burakov, A. Y.; Nikitina, I. S.; Verkhovsky, A. E.; Ilyushin, A. S.; Aladushkin, S. V.

    2017-11-01

    Regeneration plays a crucial role in the field of efficient application sodium-cationic filters for softening the water. Traditionally used as regenerant saline NaCl. However, due to the modern development of the energy industry and its close relationship with other industrial and academic sectors the opportunity to use in the regeneration of other solutions. The report estimated data and application possibilities as regenerant solution sodium-cationic filters brine wells a high mineral content, as both primary application and after balneotherapeutic use reverse osmosis and concentrates especially recycled regenerant water repeated. Comparison of the effectiveness of these solutions with the traditional use of NaCl. Developed and tested system for the processing of highly mineralized brines wells after balneological use. Recommendations for use as regeneration solutions for the sodium-cationic unit considered solutions and defined rules of brine for regeneration costs.

  8. Comparison of two disc diffusion methods with minimum inhibitory ...

    African Journals Online (AJOL)

    Susceptibility to penicillin, ciprofloxacin, tetracycline, ceftriaxone and spectinomycin and cefixime were determined by CSLI and AGSP method and Kappa statistics used to analyse the data with SPSS software. Results: All isolates were susceptible to ceftriaxone and spectinomycin by three methods. Ninety‑nine (99%) ...

  9. A comparison of five extraction methods for extracellular polymeric ...

    African Journals Online (AJOL)

    Two physical methods (centrifugation and ultrasonication) and 3 chemical methods (extraction with EDTA, extraction with formaldehyde, and extraction with formaldehyde plus NaOH) for extraction of EPS from alga-bacteria biofilm were assessed. Pretreatment with ultrasound at low intensity doubled the EPS yield without ...

  10. Validation, verification and comparison: Adopting new methods in ...

    African Journals Online (AJOL)

    2005-07-03

    Jul 3, 2005 ... chemical analyses can be assumed to be homogeneously distrib- uted. When introduced ... For water microbiology this has been resolved with the publication of .... tion exercise can result in a laboratory adopting the method. If, however, the new ... For methods used for environmental sam- ples, a range of ...

  11. Task exposures in an office environment: a comparison of methods.

    Science.gov (United States)

    Van Eerd, Dwayne; Hogg-Johnson, Sheilah; Mazumder, Anjali; Cole, Donald; Wells, Richard; Moore, Anne

    2009-10-01

    Task-related factors such as frequency and duration are associated with musculoskeletal disorders in office settings. The primary objective was to compare various task recording methods as measures of exposure in an office workplace. A total of 41 workers from different jobs were recruited from a large urban newspaper (71% female, mean age 41 years SD 9.6). Questionnaire, task diaries, direct observation and video methods were used to record tasks. A common set of task codes was used across methods. Different estimates of task duration, number of tasks and task transitions arose from the different methods. Self-report methods did not consistently result in longer task duration estimates. Methodological issues could explain some of the differences in estimates seen between methods observed. It was concluded that different task recording methods result in different estimates of exposure likely due to different exposure constructs. This work addresses issues of exposure measurement in office environments. It is of relevance to ergonomists/researchers interested in how to best assess the risk of injury among office workers. The paper discusses the trade-offs between precision, accuracy and burden in the collection of computer task-based exposure measures and different underlying constructs captures in each method.

  12. Comparison of direct and precipitation methods for the estimation of ...

    African Journals Online (AJOL)

    Background: There is increase in use of direct assays for analysis of high and low density lipoprotein cholesterol by clinical laboratories despite differences in performance characteristics with conventional precipitation methods. Calculation of low density lipoprotein cholesterol in precipitation methods is based on total ...

  13. COMPARISON OF IMAGE ENHANCEMENT METHODS FOR CHROMOSOME KARYOTYPE IMAGE ENHANCEMENT

    Directory of Open Access Journals (Sweden)

    Dewa Made Sri Arsa

    2017-02-01

    Full Text Available The chromosome is a set of DNA structure that carry information about our life. The information can be obtained through Karyotyping. The process requires a clear image so the chromosome can be evaluate well. Preprocessing have to be done on chromosome images that is image enhancement. The process starts with image background removing. The image will be cleaned background color. The next step is image enhancement. This paper compares several methods for image enhancement. We evaluate some method in image enhancement like Histogram Equalization (HE, Contrast-limiting Adaptive Histogram Equalization (CLAHE, Histogram Equalization with 3D Block Matching (HE+BM3D, and basic image enhancement, unsharp masking. We examine and discuss the best method for enhancing chromosome image. Therefore, to evaluate the methods, the original image was manipulated by the addition of some noise and blur. Peak Signal-to-noise Ratio (PSNR and Structural Similarity Index (SSIM are used to examine method performance. The output of enhancement method will be compared with result of Professional software for karyotyping analysis named Ikaros MetasystemT M . Based on experimental results, HE+BM3D method gets a stable result on both scenario noised and blur image.

  14. Comparison of glycerolisation with cryopreservation methods on HIV-1 inactivation

    International Nuclear Information System (INIS)

    Van Baare, J.; Pagnon, J.; Cameron, P.; Vardaxis, N.; Middlekoop, E.; Crowe, S.

    1999-01-01

    Cryopreservation and glycerolisation are two successful long-term preservation methods for human cadaveric donor skin, which is used in the treatment of bum patients. High concentrations of glycerol has been shown to be antibacterial and virucidal. Because fear of possible transmission of HIV-1 following allograft transplantation, this study was undertaken to investigate whether HIV can be effectively eliminated from skin explants. HIV-1 Ba-L, which has been shown to infect monocytes in skin explants and also dendritic cells, was. For the experiments we used cell-free virus, exogenously HIV infected peripheral blood mononuclear cells (PBMCs) and exogenously HIV infected cadaver split skin. Different concentrations of glycerol at various temperatures and the glycerolisation procedure as used by the Euro Skin Bank were used to determine the effects on HIV-1 Ba-L infectivity. For the cryopreservation technique we used 10% DMSO and a controlled rate freezer. HIV-1 Ba-L transfer was determined by adding uninfected PBMCs to the infected material and reverse transcriptase was measured. Cell-free HIV-1 Ba-L was not inactivated by 50% glycerol but was effectively inactivated within 30 minutes by 70% and 85% glycerol at 4 degree C, room temperature and 37 degree C. In contrast, cell-free HIV-1 Ba-L was not inactivated by cryopreservation. Most importantly, we have shown that HIV-1 Ba-L present in split skin is inactivated by incubating skin in 70% glycerol for three hours at 37-C. HIV in exogenously infected skin was not inactivated by cryopreservation. High concentrations of glycerol effectively inactivates free HIV-1 Ba-L and intracellular HIV-1 Ba-L. Also the current glycerolisation procedure carried out by the Euro Skin Bank effectively inactivates infectious virus. However, the cryopreservation technique did not show any reduction in HIV-1 Ba-L infectivity

  15. Quantitative Imaging Biomarkers: A Review of Statistical Methods for Computer Algorithm Comparisons

    Science.gov (United States)

    2014-01-01

    Quantitative biomarkers from medical images are becoming important tools for clinical diagnosis, staging, monitoring, treatment planning, and development of new therapies. While there is a rich history of the development of quantitative imaging biomarker (QIB) techniques, little attention has been paid to the validation and comparison of the computer algorithms that implement the QIB measurements. In this paper we provide a framework for QIB algorithm comparisons. We first review and compare various study designs, including designs with the true value (e.g. phantoms, digital reference images, and zero-change studies), designs with a reference standard (e.g. studies testing equivalence with a reference standard), and designs without a reference standard (e.g. agreement studies and studies of algorithm precision). The statistical methods for comparing QIB algorithms are then presented for various study types using both aggregate and disaggregate approaches. We propose a series of steps for establishing the performance of a QIB algorithm, identify limitations in the current statistical literature, and suggest future directions for research. PMID:24919829

  16. Quantitative imaging biomarkers: a review of statistical methods for computer algorithm comparisons.

    Science.gov (United States)

    Obuchowski, Nancy A; Reeves, Anthony P; Huang, Erich P; Wang, Xiao-Feng; Buckler, Andrew J; Kim, Hyun J Grace; Barnhart, Huiman X; Jackson, Edward F; Giger, Maryellen L; Pennello, Gene; Toledano, Alicia Y; Kalpathy-Cramer, Jayashree; Apanasovich, Tatiyana V; Kinahan, Paul E; Myers, Kyle J; Goldgof, Dmitry B; Barboriak, Daniel P; Gillies, Robert J; Schwartz, Lawrence H; Sullivan, Daniel C

    2015-02-01

    Quantitative biomarkers from medical images are becoming important tools for clinical diagnosis, staging, monitoring, treatment planning, and development of new therapies. While there is a rich history of the development of quantitative imaging biomarker (QIB) techniques, little attention has been paid to the validation and comparison of the computer algorithms that implement the QIB measurements. In this paper we provide a framework for QIB algorithm comparisons. We first review and compare various study designs, including designs with the true value (e.g. phantoms, digital reference images, and zero-change studies), designs with a reference standard (e.g. studies testing equivalence with a reference standard), and designs without a reference standard (e.g. agreement studies and studies of algorithm precision). The statistical methods for comparing QIB algorithms are then presented for various study types using both aggregate and disaggregate approaches. We propose a series of steps for establishing the performance of a QIB algorithm, identify limitations in the current statistical literature, and suggest future directions for research. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  17. Comparison of potential method in analytic hierarchy process for multi-attribute of catering service companies

    Science.gov (United States)

    Mamat, Siti Salwana; Ahmad, Tahir; Awang, Siti Rahmah

    2017-08-01

    Analytic Hierarchy Process (AHP) is a method used in structuring, measuring and synthesizing criteria, in particular ranking of multiple criteria in decision making problems. On the other hand, Potential Method is a ranking procedure in which utilizes preference graph ς (V, A). Two nodes are adjacent if they are compared in a pairwise comparison whereby the assigned arc is oriented towards the more preferred node. In this paper Potential Method is used to solve problem on a catering service selection. The comparison of result by using Potential method is made with Extent Analysis. The Potential Method is found to produce the same rank as Extent Analysis in AHP.

  18. Comparison of association mapping methods in a complex pedigreed population

    DEFF Research Database (Denmark)

    Sahana, Goutam; Guldbrandtsen, Bernt; Janss, Luc

    2010-01-01

    to collect SNP signals in intervals, to avoid the scattering of a QTL signal over multiple neighboring SNPs. Methods not accounting for genetic background (full pedigree information) performed worse, and methods using haplotypes were considerably worse with a high false-positive rate, probably due...... to the presence of low-frequency haplotypes. It was necessary to account for full relationships among individuals to avoid excess false discovery. Although the methods were tested on a cattle pedigree, the results are applicable to any population with a complex pedigree structure...

  19. Comparison between calculation methods of dose rates in gynecologic brachytherapy

    International Nuclear Information System (INIS)

    Vianello, E.A.; Biaggio, M.F.; D R, M.F.; Almeida, C.E. de

    1998-01-01

    In treatments with radiations for gynecologic tumors is necessary to evaluate the quality of the results obtained by different calculation methods for the dose rates on the points of clinical interest (A, rectal, vesicle). The present work compares the results obtained by two methods. The Manual Calibration Method (MCM) tri dimensional (Vianello E., et.al. 1998), using orthogonal radiographs for each patient in treatment, and the Theraplan/T P-11 planning system (Thratonics International Limited 1990) this last one verified experimentally (Vianello et.al. 1996). The results show that MCM can be used in the physical-clinical practice with a percentile difference comparable at the computerized programs. (Author)

  20. A statistical comparison of accelerated concrete testing methods

    Directory of Open Access Journals (Sweden)

    Denny Meyer

    1997-01-01

    Full Text Available Accelerated curing results, obtained after only 24 hours, are used to predict the 28 day strength of concrete. Various accelerated curing methods are available. Two of these methods are compared in relation to the accuracy of their predictions and the stability of the relationship between their 24 hour and 28 day concrete strength. The results suggest that Warm Water accelerated curing is preferable to Hot Water accelerated curing of concrete. In addition, some other methods for improving the accuracy of predictions of 28 day strengths are suggested. In particular the frequency at which it is necessary to recalibrate the prediction equation is considered.

  1. Development and comparison of Bayesian modularization method in uncertainty assessment of hydrological models

    Science.gov (United States)

    Li, L.; Xu, C.-Y.; Engeland, K.

    2012-04-01

    With respect to model calibration, parameter estimation and analysis of uncertainty sources, different approaches have been used in hydrological models. Bayesian method is one of the most widely used methods for uncertainty assessment of hydrological models, which incorporates different sources of information into a single analysis through Bayesian theorem. However, none of these applications can well treat the uncertainty in extreme flows of hydrological models' simulations. This study proposes a Bayesian modularization method approach in uncertainty assessment of conceptual hydrological models by considering the extreme flows. It includes a comprehensive comparison and evaluation of uncertainty assessments by a new Bayesian modularization method approach and traditional Bayesian models using the Metropolis Hasting (MH) algorithm with the daily hydrological model WASMOD. Three likelihood functions are used in combination with traditional Bayesian: the AR (1) plus Normal and time period independent model (Model 1), the AR (1) plus Normal and time period dependent model (Model 2) and the AR (1) plus multi-normal model (Model 3). The results reveal that (1) the simulations derived from Bayesian modularization method are more accurate with the highest Nash-Sutcliffe efficiency value, and (2) the Bayesian modularization method performs best in uncertainty estimates of entire flows and in terms of the application and computational efficiency. The study thus introduces a new approach for reducing the extreme flow's effect on the discharge uncertainty assessment of hydrological models via Bayesian. Keywords: extreme flow, uncertainty assessment, Bayesian modularization, hydrological model, WASMOD

  2. Data Mining Methods Applied to Flight Operations Quality Assurance Data: A Comparison to Standard Statistical Methods

    Science.gov (United States)

    Stolzer, Alan J.; Halford, Carl

    2007-01-01

    In a previous study, multiple regression techniques were applied to Flight Operations Quality Assurance-derived data to develop parsimonious model(s) for fuel consumption on the Boeing 757 airplane. The present study examined several data mining algorithms, including neural networks, on the fuel consumption problem and compared them to the multiple regression results obtained earlier. Using regression methods, parsimonious models were obtained that explained approximately 85% of the variation in fuel flow. In general data mining methods were more effective in predicting fuel consumption. Classification and Regression Tree methods reported correlation coefficients of .91 to .92, and General Linear Models and Multilayer Perceptron neural networks reported correlation coefficients of about .99. These data mining models show great promise for use in further examining large FOQA databases for operational and safety improvements.

  3. Pyrrolizidine alkaloids in honey: comparison of analytical methods

    NARCIS (Netherlands)

    Kempf, M.; Wittig, M.; Reinhard, A.; Ohe, von der K.; Blacquière, T.; Raezke, K.P.; Michel, R.; Schreier, P.; Beuerle, T.

    2011-01-01

    Pyrrolizidine alkaloids (PAs) are a structurally diverse group of toxicologically relevant secondary plant metabolites. Currently, two analytical methods are used to determine PA content in honey. To achieve reasonably high sensitivity and selectivity, mass spectrometry detection is demanded. One

  4. Comparison of surrogate models with different methods in ...

    Indian Academy of Sciences (India)

    In this article, polynomial regression (PR), radial basis function artificial neural network (RBFANN), and kriging ..... 10 kriging models with different parameters were also obtained. ..... shapes using stochastic optimization methods and com-.

  5. Comparison of certain microbial counting methods which are ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-12-15

    Dec 15, 2009 ... tinuous food analyses. For example, the ... plate method for the enumeration of E. coli in foods. How- ... Although its preservation for 48 h is recommended in certain ..... Innovative Fungicide For Leather Industry: Essential Oil of.

  6. Teaching Idiomatic Expressions: A Comparison of Two Instructional Methods.

    Science.gov (United States)

    Rittenhouse, Robert K.; Kenyon, Patricia L.

    1990-01-01

    Twenty hearing-impaired adolescents were taught idiomatic expressions using captioned videotape presentations followed by classroom discussion, or by extended classroom discussions. Improvement in understanding idioms was significantly greater under the videotape method. (Author/JDD)

  7. Comparison of protein extraction methods suitable for proteomics ...

    African Journals Online (AJOL)

    Jane

    2011-07-27

    Jul 27, 2011 ... An efficient protein extraction method is a prerequisite for successful implementation of proteomics. ... research, it is noteworthy to discover a proteome ..... Proteomic analysis of rice (Oryza sativa) seeds during germination.

  8. Comparison of matrix methods for elastic wave scattering problems

    International Nuclear Information System (INIS)

    Tsao, S.J.; Varadan, V.K.; Varadan, V.V.

    1983-01-01

    This article briefly describes the T-matrix method and the MOOT (method of optimal truncation) of elastic wave scattering as they apply to A-D, SH- wave problems as well as 3-D elastic wave problems. Two methods are compared for scattering by elliptical cylinders as well as oblate spheroids of various eccentricity as a function of frequency. Convergence, and symmetry of the scattering cross section are also compared for ellipses and spheroidal cavities of different aspect ratios. Both the T-matrix approach and the MOOT were programmed on an AMDHL 470 computer using double precision arithmetic. Although the T-matrix method and MOOT are not always in agreement, it is in no way implied that any of the published results using MOOT are in error

  9. Comparison of different methods for shielding design in computed tomography

    International Nuclear Information System (INIS)

    Ciraj-Bjelac, O.; Arandjic, D.; Kosutic, D.

    2011-01-01

    The purpose of this work is to compare different methods for shielding calculation in computed tomography (CT). The BIR-IPEM (British Inst. of Radiology and Inst. of Physics in Engineering in Medicine) and NCRP (National Council on Radiation Protection) method were used for shielding thickness calculation. Scattered dose levels and calculated barrier thickness were also compared with those obtained by scatter dose measurements in the vicinity of a dedicated CT unit. Minimal requirement for protective barriers based on BIR-IPEM method ranged between 1.1 and 1.4 mm of lead demonstrating underestimation of up to 20 % and overestimation of up to 30 % when compared with thicknesses based on measured dose levels. For NCRP method, calculated thicknesses were 33 % higher (27-42 %). BIR-IPEM methodology-based results were comparable with values based on scattered dose measurements, while results obtained using NCRP methodology demonstrated an overestimation of the minimal required barrier thickness. (authors)

  10. Comparison between ASHRAE and ISO thermal transmittance calculation methods

    DEFF Research Database (Denmark)

    Blanusa, Petar; Goss, William P.; Roth, Hartwig

    2007-01-01

    is proportional to the glazing/frame sightline distance that is also proportional to the total glazing spacer length. An example calculation of the overall heat transfer and thermal transmittance (U-value or U-factor) using the two methods for a thermally broken, aluminum framed slider window is presented....... The fenestration thermal transmittance calculations analyses presented in this paper show that small differences exist between the calculated thermal transmittance values produced by the ISO and ASHRAE methods. The results also show that the overall thermal transmittance difference between the two methodologies...... decreases as the total window area (glazing plus frame) increases. Thus, the resulting difference in thermal transmittance values for the two methods is negligible for larger windows. This paper also shows algebraically that the differences between the ISO and ASHRAE methods turn out to be due to the way...

  11. Comparison of the methods for determination of scintillation light yield

    CERN Document Server

    Sysoeva, E; Zelenskaya, O

    2002-01-01

    One of the most important characteristics of scintillators is the light yield. It depends not only on the properties of scintillators, but also on the conditions of measurements. Even for widely used crystals, such as alkali halide scintillators NaI(Tl) and CsI(Tl), light yield data, obtained by various authors, are different. Therefore, it is very important to choose the convenient method of the light yield measurements. In the present work, methods for the determination of the physical light yield, based on measurements of pulse amplitude, single-electron pulses and intrinsic photomultiplier resolution are discussed. These methods have been used for the measurements of light yield of alkali halide crystals and oxide scintillators. Repeatability and reproducibility of results were determined. All these methods are rather complicated in use, not for measurements, but for further data processing. Besides that, they demand a precise determination of photoreceiver's parameters, as well as determination of light ...

  12. Comparison of different precondtioners for nonsymmtric finite volume element methods

    Energy Technology Data Exchange (ETDEWEB)

    Mishev, I.D.

    1996-12-31

    We consider a few different preconditioners for the linear systems arising from the discretization of 3-D convection-diffusion problems with the finite volume element method. Their theoretical and computational convergence rates are compared and discussed.

  13. Comparison of mentha extracts obtained by different extraction methods

    Directory of Open Access Journals (Sweden)

    Milić Slavica

    2006-01-01

    Full Text Available The different methods of mentha extraction, such as steam distillation, extraction by methylene chloride (Soxhlet extraction and supercritical fluid extraction (SFE by carbon dioxide (CO J were investigated. SFE by CO, was performed at pressure of 100 bar and temperature of40°C. The extraction yield, as well as qualitative and quantitative composition of obtained extracts, determined by GC-MS method, were compared.

  14. The Comparison of Matching Methods Using Different Measures of Balance: Benefits and Risks Exemplified within a Study to Evaluate the Effects of German Disease Management Programs on Long-Term Outcomes of Patients with Type 2 Diabetes.

    Science.gov (United States)

    Fullerton, Birgit; Pöhlmann, Boris; Krohn, Robert; Adams, John L; Gerlach, Ferdinand M; Erler, Antje

    2016-10-01

    To present a case study on how to compare various matching methods applying different measures of balance and to point out some pitfalls involved in relying on such measures. Administrative claims data from a German statutory health insurance fund covering the years 2004-2008. We applied three different covariance balance diagnostics to a choice of 12 different matching methods used to evaluate the effectiveness of the German disease management program for type 2 diabetes (DMPDM2). We further compared the effect estimates resulting from applying these different matching techniques in the evaluation of the DMPDM2. The choice of balance measure leads to different results on the performance of the applied matching methods. Exact matching methods performed well across all measures of balance, but resulted in the exclusion of many observations, leading to a change of the baseline characteristics of the study sample and also the effect estimate of the DMPDM2. All PS-based methods showed similar effect estimates. Applying a higher matching ratio and using a larger variable set generally resulted in better balance. Using a generalized boosted instead of a logistic regression model showed slightly better performance for balance diagnostics taking into account imbalances at higher moments. Best practice should include the application of several matching methods and thorough balance diagnostics. Applying matching techniques can provide a useful preprocessing step to reveal areas of the data that lack common support. The use of different balance diagnostics can be helpful for the interpretation of different effect estimates found with different matching methods. © Health Research and Educational Trust.

  15. The choice of statistical methods for comparisons of dosimetric data in radiotherapy

    International Nuclear Information System (INIS)

    Chaikh, Abdulhamid; Giraud, Jean-Yves; Perrin, Emmanuel; Bresciani, Jean-Pierre; Balosso, Jacques

    2014-01-01

    Novel irradiation techniques are continuously introduced in radiotherapy to optimize the accuracy, the security and the clinical outcome of treatments. These changes could raise the question of discontinuity in dosimetric presentation and the subsequent need for practice adjustments in case of significant modifications. This study proposes a comprehensive approach to compare different techniques and tests whether their respective dose calculation algorithms give rise to statistically significant differences in the treatment doses for the patient. Statistical investigation principles are presented in the framework of a clinical example based on 62 fields of radiotherapy for lung cancer. The delivered doses in monitor units were calculated using three different dose calculation methods: the reference method accounts the dose without tissues density corrections using Pencil Beam Convolution (PBC) algorithm, whereas new methods calculate the dose with tissues density correction for 1D and 3D using Modified Batho (MB) method and Equivalent Tissue air ratio (ETAR) method, respectively. The normality of the data and the homogeneity of variance between groups were tested using Shapiro-Wilks and Levene test, respectively, then non-parametric statistical tests were performed. Specifically, the dose means estimated by the different calculation methods were compared using Friedman’s test and Wilcoxon signed-rank test. In addition, the correlation between the doses calculated by the three methods was assessed using Spearman’s rank and Kendall’s rank tests. The Friedman’s test showed a significant effect on the calculation method for the delivered dose of lung cancer patients (p <0.001). The density correction methods yielded to lower doses as compared to PBC by on average (−5 ± 4.4 SD) for MB and (−4.7 ± 5 SD) for ETAR. Post-hoc Wilcoxon signed-rank test of paired comparisons indicated that the delivered dose was significantly reduced using density

  16. Comparison of Localization Methods for a Robot Soccer Team

    Directory of Open Access Journals (Sweden)

    H. Levent Akın

    2008-11-01

    Full Text Available In this work, several localization algorithms that are designed and implemented for Cerberus'05 Robot Soccer Team are analyzed and compared. These algorithms are used for global localization of autonomous mobile agents in the robotic soccer domain, to overcome the uncertainty in the sensors, environment and the motion model. The algorithms are Reverse Monte Carlo Localization (R-MCL, Simple Localization (S-Loc and Sensor Resetting Localization (SRL. R-MCL is a hybrid method based on both Markov Localization (ML and Monte Carlo Localization (MCL where the ML module finds the region where the robot should be and MCL predicts the geometrical location with high precision by selecting samples in this region. S-Loc is another localization method where just one sample per percept is drawn, for global localization. Within this method another novel method My Environment (ME is designed to hold the history and overcome the lack of information due to the drastically decrease in the number of samples in S-Loc. ME together with S-Loc is used in the Technical Challenges in Robocup 2005 and play an important role in ranking the First Place in the Challenges. In this work, these methods together with SRL, which is a widely used successful localization algorithm, are tested with both offline and real-time tests. First they are tested on a challenging data set that is used by many researches and compared in terms of error rate against different levels of noise, and sparsity. Besides time required recovering from kidnapping and speed of the methods are tested and compared. Then their performances are tested with real-time tests with scenarios like the ones in the Technical Challenges in ROBOCUP. The main aim is to find the best method which is very robust and fast and requires less computational power and memory compared to similar approaches and is accurate enough for high level decision making which is vital for robot soccer.

  17. Comparison of Localization Methods for a Robot Soccer Team

    Directory of Open Access Journals (Sweden)

    Hatice Kose

    2006-12-01

    Full Text Available In this work, several localization algorithms that are designed and implemented for Cerberus'05 Robot Soccer Team are analyzed and compared. These algorithms are used for global localization of autonomous mobile agents in the robotic soccer domain, to overcome the uncertainty in the sensors, environment and the motion model. The algorithms are Reverse Monte Carlo Localization (R-MCL, Simple Localization (S-Loc and Sensor Resetting Localization (SRL. R-MCL is a hybrid method based on both Markov Localization (ML and Monte Carlo Localization (MCL where the ML module finds the region where the robot should be and MCL predicts the geometrical location with high precision by selecting samples in this region. S-Loc is another localization method where just one sample per percept is drawn, for global localization. Within this method another novel method My Environment (ME is designed to hold the history and overcome the lack of information due to the drastically decrease in the number of samples in S-Loc. ME together with S-Loc is used in the Technical Challenges in Robocup 2005 and play an important role in ranking the First Place in the Challenges. In this work, these methods together with SRL, which is a widely used successful localization algorithm, are tested with both offline and real-time tests. First they are tested on a challenging data set that is used by many researches and compared in terms of error rate against different levels of noise, and sparsity. Besides time required recovering from kidnapping and speed of the methods are tested and compared. Then their performances are tested with real-time tests with scenarios like the ones in the Technical Challenges in ROBOCUP. The main aim is to find the best method which is very robust and fast and requires less computational power and memory compared to similar approaches and is accurate enough for high level decision making which is vital for robot soccer.

  18. A comparison of cosegregation analysis methods for the clinical setting.

    Science.gov (United States)

    Rañola, John Michael O; Liu, Quanhui; Rosenthal, Elisabeth A; Shirts, Brian H

    2018-04-01

    Quantitative cosegregation analysis can help evaluate the pathogenicity of genetic variants. However, genetics professionals without statistical training often use simple methods, reporting only qualitative findings. We evaluate the potential utility of quantitative cosegregation in the clinical setting by comparing three methods. One thousand pedigrees each were simulated for benign and pathogenic variants in BRCA1 and MLH1 using United States historical demographic data to produce pedigrees similar to those seen in the clinic. These pedigrees were analyzed using two robust methods, full likelihood Bayes factors (FLB) and cosegregation likelihood ratios (CSLR), and a simpler method, counting meioses. Both FLB and CSLR outperform counting meioses when dealing with pathogenic variants, though counting meioses is not far behind. For benign variants, FLB and CSLR greatly outperform as counting meioses is unable to generate evidence for benign variants. Comparing FLB and CSLR, we find that the two methods perform similarly, indicating that quantitative results from either of these methods could be combined in multifactorial calculations. Combining quantitative information will be important as isolated use of cosegregation in single families will yield classification for less than 1% of variants. To encourage wider use of robust cosegregation analysis, we present a website ( http://www.analyze.myvariant.org ) which implements the CSLR, FLB, and Counting Meioses methods for ATM, BRCA1, BRCA2, CHEK2, MEN1, MLH1, MSH2, MSH6, and PMS2. We also present an R package, CoSeg, which performs the CSLR analysis on any gene with user supplied parameters. Future variant classification guidelines should allow nuanced inclusion of cosegregation evidence against pathogenicity.

  19. Determination of chloride in water. A comparison of three methods

    International Nuclear Information System (INIS)

    Steele, P.J.

    1978-09-01

    The presence of chloride in the water circuits of nuclear reactors, power stations and experimental rigs is undesirable because of the possibility of corrosion. Three methods are considered for the determination of chloride in water in the 0 to 10 μg ml -1 range. The potentiometric method, using a silver-silver chloride electrode, is capable of determining chloride above the 0.1μg ml -1 level, with a standard deviation of 0.03 to 0.12 μg ml -1 in the range 0.1 to 6.0 μg ml -1 chloride. Bromide, iodide and strong reducing agents interfere but none of the cations likely to be present has an effect. The method is very susceptible to variations in temperature. The turbidimetric method involves the production of suspended silver chloride by the addition of silver nitride solution to the sample. The method is somewhat unreliable and is more useful as a rapid, routine limit-testing technique. In the third method, chloride in the sample is pre-concentrated by co-precipitation on lead phosphate, redissolved in acidified ferric nitrate solution and determined colorimetrically by the addition of mercuric thiocyanate solution. It is suitable for determining chloride in the range 0 to 50 μg, using a sample volume of 100 to 500 ml. None of the chemical species likely to be present interferes. In all three methods, chloride contamination can occur at any point in the determination. Analyses should be carried out in conditions where airborne contamination is minimised and a high degree of cleanliness must be maintained. (author)

  20. Comparison of Satellite Surveying to Traditional Surveying Methods for the Resources Industry

    Science.gov (United States)

    Osborne, B. P.; Osborne, V. J.; Kruger, M. L.

    Modern ground-based survey methods involve detailed survey, which provides three-space co-ordinates for surveyed points, to a high level of accuracy. The instruments are operated by surveyors, who process the raw results to create survey location maps for the subject of the survey. Such surveys are conducted for a location or region and referenced to the earth global co- ordinate system with global positioning system (GPS) positioning. Due to this referencing the survey is only as accurate as the GPS reference system. Satellite survey remote sensing utilise satellite imagery which have been processed using commercial geographic information system software. Three-space co-ordinate maps are generated, with an accuracy determined by the datum position accuracy and optical resolution of the satellite platform.This paper presents a case study, which compares topographic surveying undertaken by traditional survey methods with satellite surveying, for the same location. The purpose of this study is to assess the viability of satellite remote sensing for surveying in the resources industry. The case study involves a topographic survey of a dune field for a prospective mining project area in Pakistan. This site has been surveyed using modern surveying techniques and the results are compared to a satellite survey performed on the same area.Analysis of the results from traditional survey and from the satellite survey involved a comparison of the derived spatial co- ordinates from each method. In addition, comparisons have been made of costs and turnaround time for both methods.The results of this application of remote sensing is of particular interest for survey in areas with remote and extreme environments, weather extremes, political unrest, poor travel links, which are commonly associated with mining projects. Such areas frequently suffer language barriers, poor onsite technical support and resources.

  1. Interface and thin film analysis: Comparison of methods, trends

    International Nuclear Information System (INIS)

    Werner, H.W.; Torrisi, A.

    1990-01-01

    Thin film properties are governed by a number of parameters such as: Surface and interface chemical composition, microstructure and the distribution of defects, dopants and impurities. For the determination of most of these aspects sophisticated analytical methods are needed. An overview of these analytical methods is given including: - Features and modes of analytical methods; - Main characteristics, advantages and disadvantages of the established methods [e.g. ESCA (Electron Spectroscopy for Chemical Analysis), AES (Auger Electron Spectroscopy), SIMS (Secondary Ion Mass Spectrometry), RBS (Rutherford Backscattering Spectrometry), SEM (Scanning Electron Microscopy), TEM (Transmission Electron Microscopy), illustrated with typical examples]; - Presentation of relatively new methods such as XRM (X-ray Microscopy) and SCAM (Scanning Acoustic Microscopy). Some features of ESCA (chemical information, insulator analysis, non-destructive depth profiling) have been selected for a more detailed presentation, viz. to illustrate the application of ESCA to practical problems. Trends in instrumental development and analytical applications of the techniques are discussed; the need for a multi-technique approach to solve complex analytical problems is emphasized. (orig.)

  2. Comparison of matrix exponential methods for fuel burnup calculations

    International Nuclear Information System (INIS)

    Oh, Hyung Suk; Yang, Won Sik

    1999-01-01

    Series expansion methods to compute the exponential of a matrix have been compared by applying them to fuel depletion calculations. Specifically, Taylor, Pade, Chebyshev, and rational Chebyshev approximations have been investigated by approximating the exponentials of bum matrices by truncated series of each method with the scaling and squaring algorithm. The accuracy and efficiency of these methods have been tested by performing various numerical tests using one thermal reactor and two fast reactor depletion problems. The results indicate that all the four series methods are accurate enough to be used for fuel depletion calculations although the rational Chebyshev approximation is relatively less accurate. They also show that the rational approximations are more efficient than the polynomial approximations. Considering the computational accuracy and efficiency, the Pade approximation appears to be better than the other methods. Its accuracy is better than the rational Chebyshev approximation, while being comparable to the polynomial approximations. On the other hand, its efficiency is better than the polynomial approximations and is similar to the rational Chebyshev approximation. In particular, for fast reactor depletion calculations, it is faster than the polynomial approximations by a factor of ∼ 1.7. (author). 11 refs., 4 figs., 2 tabs

  3. Comparison of attitudes related with family planning methods before and after effective family planning counseling.

    Directory of Open Access Journals (Sweden)

    Esra Esim Büyükbayrak

    2010-09-01

    Full Text Available Objective: To evaluate the effect of family planning counseling on the changeover of the family planning method and to determine level of knowledge of participants on family planning methods and their attitude towards changeover of the method after counseling. Setting: Kartal education and reseach hospital obstetrics and gynecology clinic, department of family planning. Patients. 500 consecutive women applying to family planning department for any reason. Interventions: Effective family planning counseling service was given to each participant then a questioner containin 14 questions was applied with face to face technique. Main Outcome Measures: Attitude towards family planning counseling, comparison of the preference of family planning method before and after family planning counseling service and influential sociodemographic parameters on method choise were studied. Results: 45,2% of the participants were not taken family planning counseling service before. knowledge on family planning methods was sufficient in 25,2% of the participants, insufficient in 56,8% of the participants and 18% of the participants reported that they have no idea. 57,8% of the participants change mind about family planning counseling. 52,2% of the participants changeover perious method after counseling. 99,4% of the participants said that family planning counseling service should be given to every women. Preference of family planning method before and after family planning counseling service was statistically significantly different (p<0.01. Educational level, income and age were found to be influential sociodemographic factors for method preference. Conclusions: Effective family planning counseling service is found to have favorable effect on attitude and knowledge about family planning methods. Modern method usage increase as educational level and income of the participants increase.

  4. A comparison of non-integrating reprogramming methods

    Science.gov (United States)

    Schlaeger, Thorsten M; Daheron, Laurence; Brickler, Thomas R; Entwisle, Samuel; Chan, Karrie; Cianci, Amelia; DeVine, Alexander; Ettenger, Andrew; Fitzgerald, Kelly; Godfrey, Michelle; Gupta, Dipti; McPherson, Jade; Malwadkar, Prerana; Gupta, Manav; Bell, Blair; Doi, Akiko; Jung, Namyoung; Li, Xin; Lynes, Maureen S; Brookes, Emily; Cherry, Anne B C; Demirbas, Didem; Tsankov, Alexander M; Zon, Leonard I; Rubin, Lee L; Feinberg, Andrew P; Meissner, Alexander; Cowan, Chad A; Daley, George Q

    2015-01-01

    Human induced pluripotent stem cells (hiPSCs1–3) are useful in disease modeling and drug discovery, and they promise to provide a new generation of cell-based therapeutics. To date there has been no systematic evaluation of the most widely used techniques for generating integration-free hiPSCs. Here we compare Sendai-viral (SeV)4, episomal (Epi)5 and mRNA transfection mRNA6 methods using a number of criteria. All methods generated high-quality hiPSCs, but significant differences existed in aneuploidy rates, reprogramming efficiency, reliability and workload. We discuss the advantages and shortcomings of each approach, and present and review the results of a survey of a large number of human reprogramming laboratories on their independent experiences and preferences. Our analysis provides a valuable resource to inform the use of specific reprogramming methods for different laboratories and different applications, including clinical translation. PMID:25437882

  5. Comparison of three methods for identification of pathogenic Neisseria species

    Energy Technology Data Exchange (ETDEWEB)

    Appelbaum, P.C.; Lawrence, R.B.

    1979-05-01

    A radiometric procedure was compared with the Minitek and Cystine Trypticase Agar sugar degradation methods for identification of 113 Neisseria species (58 Neisseria meningitidis, 51 Neisseria gonorrhoeae, 2 Neisseria lactamica, 2 Neisseria sicca). Identification of meningococci and gonoccoi was confirmed by agglutination and fluorescent antibody techniques, respectively. The Minitek method identified 97% of meningococci, 92% of gonococci, and 100% of other Neisseria after 4 h of incubation. The radiometric (Bactec) procedure identified 100% of gonococci and 100% of miscellaneous Neisseria after 3 h, but problems were encountered with meningococci: 45% of the later strains yielded index values for fructose between 20 and 28 (recommended negative cut-off point, less than 20), with strongly positive (greater than 100) glucose and maltose and negative o-nitrophenyl-beta-0-galactopyranoside reactions in all 58 strains. The Cystine Trypticase Agar method identified 91% of meningococci, ases.

  6. Comparison between powder and slices diffraction methods in teeth samples

    Energy Technology Data Exchange (ETDEWEB)

    Colaco, Marcos V.; Barroso, Regina C. [Universidade do Estado do Rio de Janeiro (IF/UERJ), RJ (Brazil). Inst. de Fisica. Dept. de Fisica Aplicada; Porto, Isabel M. [Universidade Estadual de Campinas (FOP/UNICAMP), Piracicaba, SP (Brazil). Fac. de Odontologia. Dept. de Morfologia; Gerlach, Raquel F. [Universidade de Sao Paulo (FORP/USP), Rieirao Preto, SP (Brazil). Fac. de Odontologia. Dept. de Morfologia, Estomatologia e Fisiologia; Costa, Fanny N. [Coordenacao dos Programas de Pos-Graduacao de Engenharia (LIN/COPPE/UFRJ), RJ (Brazil). Lab. de Instrumentacao Nuclear

    2011-07-01

    Propose different methods to obtain crystallographic information about biological materials are important since powder method is a nondestructive method. Slices are an approximation of what would be an in vivo analysis. Effects of samples preparation cause differences in scattering profiles compared with powder method. The main inorganic component of bones and teeth is a calcium phosphate mineral whose structure closely resembles hydroxyapatite (HAp). The hexagonal symmetry, however, seems to work well with the powder diffraction data, and the crystal structure of HAp is usually described in space group P63/m. Were analyzed ten third molar teeth. Five teeth were separated in enamel, detin and circumpulpal detin powder and five in slices. All the scattering profile measurements were carried out at the X-ray diffraction beamline (XRD1) at the National Synchrotron Light Laboratory - LNLS, Campinas, Brazil. The LNLS synchrotron light source is composed of a 1.37 GeV electron storage ring, delivering approximately 4x10{sup -1}0 photons/s at 8 keV. A double-crystal Si(111) pre-monochromator, upstream of the beamline, was used to select a small energy bandwidth at 11 keV . Scattering signatures were obtained at intervals of 0.04 deg for angles from 24 deg to 52 deg. The human enamel experimental crystallite size obtained in this work were 30(3)nm (112 reflection) and 30(3)nm (300 reflection). These values were obtained from measurements of powdered enamel. When comparing the slice obtained 58(8)nm (112 reflection) and 37(7)nm (300 reflection) enamel diffraction patterns with those generated by the powder specimens, a few differences emerge. This work shows differences between powder and slices methods, separating characteristics of sample of the method's influence. (author)

  7. CT hepatic perfusion measurement: Comparison of three analytic methods

    International Nuclear Information System (INIS)

    Kanda, Tomonori; Yoshikawa, Takeshi; Ohno, Yoshiharu; Kanata, Naoki; Koyama, Hisanobu; Takenaka, Daisuke; Sugimura, Kazuro

    2012-01-01

    Objectives: To compare the efficacy of three analytic methods, maximum slope (MS), dual-input single-compartment model (CM) and deconvolution (DC), for CT measurements of hepatic perfusion and assess the effects of extra-hepatic systemic factors. Materials and methods: Eighty-eight patients who were suspected of having metastatic liver tumors underwent hepatic CT perfusion. The scans were performed at the hepatic hilum 7–77 s after administration of contrast material. Hepatic arterial and portal perfusions (HAP and HPP, ml/min/100 ml) and arterial perfusion fraction (APF, %) were calculated with the three methods, followed by correlation assessment. Partial correlation analysis was used to assess the effects on hepatic perfusion values by various factors such as age, sex, risk of cardiovascular diseases, arrival time of contrast material at abdominal aorta, transit time from abdominal aorta to hepatic parenchyma, and liver dysfunction. Results: Mean HAP of MS was significantly higher than DC. HPP of CM was significantly higher than MS and CM, and HPP of MS was significantly higher than DC. There was no significant difference in APF. HAP and APF showed significant and moderate correlations among the methods. HPP showed significant and moderate correlations between CM and DC, and poor correlation between MS and CM or DC. All methods showed weak correlations between HAP or APF and age or sex. Finally, MS showed weak correlations between HAP or HPP and arrival time or cardiovascular risks. Conclusions: Hepatic perfusion values arrived at with the three methods are not interchangeable. CM and DC are less susceptible to extra-hepatic systemic factors

  8. Analysis and Comparison of Objective Methods for Image Quality Assessment

    Directory of Open Access Journals (Sweden)

    P. S. Babkin

    2014-01-01

    Full Text Available The purpose of this work is research and modification of the reference objective methods for image quality assessment. The ultimate goal is to obtain a modification of formal assessments that more closely corresponds to the subjective expert estimates (MOS.In considering the formal reference objective methods for image quality assessment we used the results of other authors, which offer results and comparative analyzes of the most effective algorithms. Based on these investigations we have chosen two of the most successful algorithm for which was made a further analysis in the MATLAB 7.8 R 2009 a (PQS and MSSSIM. The publication focuses on the features of the algorithms, which have great importance in practical implementation, but are insufficiently covered in the publications by other authors.In the implemented modification of the algorithm PQS boundary detector Kirsch was replaced by the boundary detector Canny. Further experiments were carried out according to the method of the ITU-R VT.500-13 (01/2012 using monochrome images treated with different types of filters (should be emphasized that an objective assessment of image quality PQS is applicable only to monochrome images. Images were obtained with a thermal imaging surveillance system. The experimental results proved the effectiveness of this modification.In the specialized literature in the field of formal to evaluation methods pictures, this type of modification was not mentioned.The method described in the publication can be applied to various practical implementations of digital image processing.Advisability and effectiveness of using the modified method of PQS to assess the structural differences between the images are shown in the article and this will be used in solving the problems of identification and automatic control.

  9. Soybean phospholipase D activity determination. A comparison of two methods

    Directory of Open Access Journals (Sweden)

    Ré, E.

    2007-09-01

    Full Text Available Due to a discrepancy between previously published results, two methods to determine the soybean phospholipase D activity were evaluated. One method is based on the extraction of the enzyme from whole soybean flour, quantifying the enzyme activity on the extract. The other method quantifies the enzymatic activity on whole soybean flour without enzyme extraction. In the extraction-based-method, both the extraction time and the number of extractions were optimized. The highest phospholipase D activity values were obtained from the method without enzyme extraction. This method is less complex, requires less running-time and the conditions of the medium in which phospholipase D acts resemble the conditions found in the oil industrySe evaluaron dos métodos para determinar la actividad de la fosfolipasa D en soja debido a que existe discrepancia entre los resultados publicados. Un método se basa en la extracción de la enzima de la harina resultante de la molienda del grano de soja entero, cuantificando la actividad sobre el extracto. En el otro método, la cuantificación se realiza sobre la harina del grano entero molido, sin extraer la enzima. En el método de extracción se optimizaron tanto el tiempo como el número de extracciones. Los mayores valores de actividad de la fosfolipasa D se obtuvieron por el método sin extracción de la enzima. Este método es más simple, exige menos tiempo de ejecución y las condiciones del medio en que actúa la fosfolipasa D se asemejan a las condiciones encontradas en la industria aceitera.

  10. Comparison of high efficiency particulate filter testing methods

    International Nuclear Information System (INIS)

    1985-01-01

    High Efficiency Particulate Air (HEPA) filters are used for the removal of submicron size particulates from air streams. In nuclear industry they are used as an important engineering safeguard to prevent the release of air borne radioactive particulates to the environment. HEPA filters used in the nuclear industry should therefore be manufactured and operated under strict quality control. There are three levels of testing HEPA filters: i) testing of the filter media; ii) testing of the assembled filter including filter media and filter housing; and iii) on site testing of the complete filter installation before putting into operation and later for the purpose of periodic control. A co-ordinated research programme on particulate filter testing methods was taken up by the Agency and contracts were awarded to the Member Countries, Belgium, German Democratic Republic, India and Hungary. The investigations carried out by the participants of the present co-ordinated research programme include the results of the nowadays most frequently used HEPA filter testing methods both for filter medium test, rig test and in-situ test purposes. Most of the experiments were carried out at ambient temperature and humidity, but indications were given to extend the investigations to elevated temperature and humidity in the future for the purpose of testing the performance of HEPA filter under severe conditions. A major conclusion of the co-ordinated research programme was that it was not possible to recommend one method as a reference method for in situ testing of high efficiency particulate air filters. Most of the present conventional methods are adequate for current requirements. The reasons why no method is to be recommended were multiple, ranging from economical aspects, through incompatibility of materials to national regulations

  11. Comparison between powder and slices diffraction methods in teeth samples

    International Nuclear Information System (INIS)

    Colaco, Marcos V.; Barroso, Regina C.; Porto, Isabel M.; Gerlach, Raquel F.; Costa, Fanny N.

    2011-01-01

    Propose different methods to obtain crystallographic information about biological materials are important since powder method is a nondestructive method. Slices are an approximation of what would be an in vivo analysis. Effects of samples preparation cause differences in scattering profiles compared with powder method. The main inorganic component of bones and teeth is a calcium phosphate mineral whose structure closely resembles hydroxyapatite (HAp). The hexagonal symmetry, however, seems to work well with the powder diffraction data, and the crystal structure of HAp is usually described in space group P63/m. Were analyzed ten third molar teeth. Five teeth were separated in enamel, detin and circumpulpal detin powder and five in slices. All the scattering profile measurements were carried out at the X-ray diffraction beamline (XRD1) at the National Synchrotron Light Laboratory - LNLS, Campinas, Brazil. The LNLS synchrotron light source is composed of a 1.37 GeV electron storage ring, delivering approximately 4x10 -1 0 photons/s at 8 keV. A double-crystal Si(111) pre-monochromator, upstream of the beamline, was used to select a small energy bandwidth at 11 keV . Scattering signatures were obtained at intervals of 0.04 deg for angles from 24 deg to 52 deg. The human enamel experimental crystallite size obtained in this work were 30(3)nm (112 reflection) and 30(3)nm (300 reflection). These values were obtained from measurements of powdered enamel. When comparing the slice obtained 58(8)nm (112 reflection) and 37(7)nm (300 reflection) enamel diffraction patterns with those generated by the powder specimens, a few differences emerge. This work shows differences between powder and slices methods, separating characteristics of sample of the method's influence. (author)

  12. Comparison of topotactic fluorination methods for complex oxide films

    Science.gov (United States)

    Moon, E. J.; Choquette, A. K.; Huon, A.; Kulesa, S. Z.; Barbash, D.; May, S. J.

    2015-06-01

    We have investigated the synthesis of SrFeO3-αFγ (α and γ ≤ 1) perovskite films using topotactic fluorination reactions utilizing poly(vinylidene fluoride) as a fluorine source. Two different fluorination methods, a spin-coating and a vapor transport approach, were performed on as-grown SrFeO2.5 films. We highlight differences in the structural, compositional, and optical properties of the oxyfluoride films obtained via the two methods, providing insight into how fluorination reactions can be used to modify electronic and optical behavior in complex oxide heterostructures.

  13. Comparison of topotactic fluorination methods for complex oxide films

    Energy Technology Data Exchange (ETDEWEB)

    Moon, E. J., E-mail: em582@drexel.edu; Choquette, A. K.; Huon, A.; Kulesa, S. Z.; May, S. J., E-mail: smay@coe.drexel.edu [Department of Materials Science and Engineering, Drexel University, Philadelphia, Pennsylvania 19104 (United States); Barbash, D. [Centralized Research Facilities, Drexel University, Philadelphia, Pennsylvania 19104 (United States)

    2015-06-01

    We have investigated the synthesis of SrFeO{sub 3−α}F{sub γ} (α and γ ≤ 1) perovskite films using topotactic fluorination reactions utilizing poly(vinylidene fluoride) as a fluorine source. Two different fluorination methods, a spin-coating and a vapor transport approach, were performed on as-grown SrFeO{sub 2.5} films. We highlight differences in the structural, compositional, and optical properties of the oxyfluoride films obtained via the two methods, providing insight into how fluorination reactions can be used to modify electronic and optical behavior in complex oxide heterostructures.

  14. Comparison of optimization methods for electronic-structure calculations

    International Nuclear Information System (INIS)

    Garner, J.; Das, S.G.; Min, B.I.; Woodward, C.; Benedek, R.

    1989-01-01

    The performance of several local-optimization methods for calculating electronic structure is compared. The fictitious first-order equation of motion proposed by Williams and Soler is integrated numerically by three procedures: simple finite-difference integration, approximate analytical integration (the Williams-Soler algorithm), and the Born perturbation series. These techniques are applied to a model problem for which exact solutions are known, the Mathieu equation. The Williams-Soler algorithm and the second Born approximation converge equally rapidly, but the former involves considerably less computational effort and gives a more accurate converged solution. Application of the method of conjugate gradients to the Mathieu equation is discussed

  15. Formal Methods for Abstract Specifications – A Comparison of Concepts

    DEFF Research Database (Denmark)

    Instenberg, Martin; Schneider, Axel; Schnetter, Sabine

    2006-01-01

    In industry formal methods are becoming increasingly important for the verification of hardware and software designs. However current practice for specification of system and protocol functionality on high level of abstraction is textual description. For verification of the system behavior manual...... inspections and tests are usual means. To facilitate the introduction of formal methods in the development process of complex systems and protocols, two different tools evolved from research activities – UPPAAL and SpecEdit – have been investigated and compared regarding their concepts and functionality...

  16. Municipal solid waste processing methods: Technical-economic comparison

    International Nuclear Information System (INIS)

    Bertanza, G.

    1993-01-01

    This paper points out the advantages and disadvantages of municipal solid waste processing methods incorporating different energy and/or materials recovery techniques, i.e., those involving composting or incineration and those with a mix of composting and incineration. The various technologies employed are compared especially with regard to process reliability, flexibility, modularity, pollution control efficiency and cost effectiveness. For that which regards composting, biodigestors are examined, while for incineration, the paper analyzes systems using combustion with complete recovery of vapour, combustion with total recovery of available electric energy, and combustion with cogeneration. Each of the processing methods examined includes an iron recovery cycle

  17. COMPARISON OF NONLINEAR DYNAMICS OPTIMIZATION METHODS FOR APS-U

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Y.; Borland, Michael

    2017-06-25

    Many different objectives and genetic algorithms have been proposed for storage ring nonlinear dynamics performance optimization. These optimization objectives include nonlinear chromaticities and driving/detuning terms, on-momentum and off-momentum dynamic acceptance, chromatic detuning, local momentum acceptance, variation of transverse invariant, Touschek lifetime, etc. In this paper, the effectiveness of several different optimization methods and objectives are compared for the nonlinear beam dynamics optimization of the Advanced Photon Source upgrade (APS-U) lattice. The optimized solutions from these different methods are preliminarily compared in terms of the dynamic acceptance, local momentum acceptance, chromatic detuning, and other performance measures.

  18. Comparison of topotactic fluorination methods for complex oxide films

    Directory of Open Access Journals (Sweden)

    E. J. Moon

    2015-06-01

    Full Text Available We have investigated the synthesis of SrFeO3−αFγ (α and γ ≤ 1 perovskite films using topotactic fluorination reactions utilizing poly(vinylidene fluoride as a fluorine source. Two different fluorination methods, a spin-coating and a vapor transport approach, were performed on as-grown SrFeO2.5 films. We highlight differences in the structural, compositional, and optical properties of the oxyfluoride films obtained via the two methods, providing insight into how fluorination reactions can be used to modify electronic and optical behavior in complex oxide heterostructures.

  19. Statistical comparison of excystation methods in Cryptosporidium parvum oocysts

    Czech Academy of Sciences Publication Activity Database

    Pecková, R.; Stuart, P. D.; Sak, Bohumil; Květoňová, Dana; Kváč, Martin; Foitová, I.

    2016-01-01

    Roč. 230, OCT 30 (2016), s. 1-5 ISSN 0304-4017 R&D Projects: GA ČR(CZ) GAP505/11/1163 Institutional support: RVO:60077344 Keywords : Cryptosporidium parvum * excystation methods * in vitro cultivation * sodium hypochlorite * tlypsin Subject RIV: EG - Zoology Impact factor: 2.356, year: 2016

  20. "A Comparison of Several Methods in a Rock Slope Stability ...

    African Journals Online (AJOL)

    This researchuses the mentioned methods and principles in the stability analysis of some rock slopes in an open pit mine in Syria, that is Khneifees phosphate mine. The importance of this researchis that it shows the role of kinematical analysis in minimizing efforts when verifying the safety of rock slopes in site, and when ...

  1. Comparison of design methods for axially loaded buckets in sand

    DEFF Research Database (Denmark)

    Vaitkunaite, Evelina; Nielsen, Benjaminn Nordahl; Ibsen, Lars Bo

    2015-01-01

    . Itwas found that bearing capacity from the surcharge increases approximately twice if the foundation skirt is two times longer. However, the predicted compressive soil capacity can differ by 3.6 times depending on the chosen bearing capacity parameters. Few methods are available for the estimation...

  2. Comparison of methods for cryostating superconducting dipole magnets

    International Nuclear Information System (INIS)

    Son Zun Gan; Filippov, Yu.P.; Zinchenko, S.I.

    1985-01-01

    An attempt is made to refine basic parameters of the UNK cryogenic system with account of real characteristics of horizontal two-phase helium flows and to project ways of optimizing these parameters. The method 1 where liquid helium in the state close to saturation is supplied to the chain of magnets and removes heat releasing in coils and coming from environment at the expense of phase transformation and it leaves the chain as vapour-liquid mixture, is compared with the method 2 where magnet cooling is arranged at the expense of heat transfer from one-phase direct flow to two-phase helium counter flow. The results of calculations are presented as dependences of maximum temperatures of coils on the length of magnetic path. It is shown that at the length of chain of about 300-400 m both methods are practically equivalent by temperature criterion, but the method 1 is preferable due to simpler design of the cryostat and lesser helium quantity in the system

  3. COMPARISON OF LARGE RIVER SAMPLING METHODS ON ALGAL METRICS

    Science.gov (United States)

    We compared the results of four methods used to assess the algal communities at 60 sites distributed among four rivers. Based on Principle Component Analysis of physical habitat data collected concomitantly with the algal data, sites were separated into those with a mean thalweg...

  4. COMPARISON OF LARGE RIVER SAMPLING METHOD USING DIATOM METRICS

    Science.gov (United States)

    We compared the results of four methods used to assess the algal communities at 60 sites distributed among four rivers. Based on Principle Component Analysis of physical habitat data collected concomitantly with the algal data, sites were separated into those with a mean thalweg...

  5. Comparison of two detection methods in thin layer chromatographic ...

    African Journals Online (AJOL)

    o-tolidine plus potassium iodide and photosynthesis inhibition detection methods were investigated for the analysis of three triazine herbicides (atrazine, ametryne, simazine) and two urea herbicides (diuron, metobromuron) in a coastal savanna soil using thin layer chromatography to compare the suitability of the two ...

  6. Predicting proteasomal cleavage sites: a comparison of available methods

    DEFF Research Database (Denmark)

    Saxova, P.; Buus, S.; Brunak, Søren

    2003-01-01

    -terminal, in particular, of CTL epitopes is cleaved precisely by the proteasome, whereas the N-terminal is produced with an extension, and later trimmed by peptidases in the cytoplasm and in the endoplasmic reticulum. Recently, three publicly available methods have been developed for prediction of the specificity...

  7. Comparison of Two Disc Diffusion Methods with Minimum Inhibitory ...

    African Journals Online (AJOL)

    antimicrobial susceptibility pattern of N. gonorrhoeae may change rapidly, especially in areas where ineffective treatment regimens are applied.[3]. There are no universally accepted guidelines for testing the antimicrobial susceptibility of N. gonorrhoeae by a disc diffusion method, but different techniques are in practice, like ...

  8. Comparison of three methods for determination of protein ...

    African Journals Online (AJOL)

    However, a six fold greater amount of protein was obtained when FastPrep was applied to lyse LAB cells. Our results also indicate that, this fast and easy extraction method allows more spot-abundant polyacrylamide gels. More clear and consistent strips were detected by SDS-PAGE when proteins were extracted by ...

  9. A comparison of multidimensional scaling methods for perceptual mapping

    NARCIS (Netherlands)

    Bijmolt, T.H.A.; Wedel, M.

    Multidimensional scaling has been applied to a wide range of marketing problems, in particular to perceptual mapping based on dissimilarity judgments. The introduction of methods based on the maximum likelihood principle is one of the most important developments. In this article, the authors compare

  10. Comparison of different methods to investigate postprandial lipaemia

    NARCIS (Netherlands)

    van Oostrom, A. J. H. H. M.; Alipour, A.; Sijmonsma, T. P.; Verseyden, C.; Dallinga-Thie, G. M.; Plokker, H. W. M.; Castro Cabezas, M.

    2009-01-01

    Postprandial hyperlipidaemia has been associated with coronary artery disease (CAD). We investigated which of the generally used methods to test postprandial lipaemia differentiated best between patients with premature CAD (50 +/- 4 years, n=20) and healthy controls. Furthermore, the effects of

  11. Comparison between implicit and hybrid solvation methods for the ...

    Indian Academy of Sciences (India)

    Administrator

    Both implicit solvation method (dielectric polarizable continuum model, DPCM) and hybrid ... the free energy change (ΔGsol) as per the PCM ... Here the gas phase change is written as ΔGg = ΔEelec + ..... bution to the field of electrochemistry.

  12. A comparison of three methods of Nitrogen analysis for feedstuffs

    African Journals Online (AJOL)

    Unknown

    Introduction. The Kjeldahl method for determining crude protein is very widely used for analysis of feed samples. However, it has its drawbacks and hence new techniques which are without some of the disadvantages are considered desirable. One such modification was developed by Hach et al. (1987). This promising ...

  13. Comparison of multiple gene assembly methods for metabolic engineering

    Science.gov (United States)

    Chenfeng Lu; Karen Mansoorabadi; Thomas Jeffries

    2007-01-01

    A universal, rapid DNA assembly method for efficient multigene plasmid construction is important for biological research and for optimizing gene expression in industrial microbes. Three different approaches to achieve this goal were evaluated. These included creating long complementary extensions using a uracil-DNA glycosylase technique, overlap extension polymerase...

  14. Comparison of Methods for Sparse Representation of Musical Signals

    DEFF Research Database (Denmark)

    Endelt, Line Ørtoft; la Cour-Harbo, Anders

    2005-01-01

    by a number of sparseness measures and results are shown on the ℓ1 norm of the coefficients, using a dictionary containing a Dirac basis, a Discrete Cosine Transform, and a Wavelet Packet. Evaluated only on the sparseness Matching Pursuit is the best method, and it is also relatively fast....

  15. Preliminary comparison of different reduction methods of graphene

    Indian Academy of Sciences (India)

    The reduction of graphene oxide (GO) is a promising route to bulk produce graphene-based sheets. Different reduction processes result in reduced graphene oxide (RGO) with different properties. In this paper three reduction methods, chemical, thermal and electrochemical reduction, were compared on three aspects ...

  16. Comparison of the performances and validation of three methods for ...

    African Journals Online (AJOL)

    SARAH

    2014-02-28

    Feb 28, 2014 ... bacteria in Norwegian slaughter pigs. Int J. Food Microbiol 1, 301–309. [NCFA] Nordic Committee of Food Analysis (1996). Yersinia enterocolitica Detection in foods 117,. 3rd,edn,1-12. Nowak, B., Mueffling, T.V., Caspari, K. and Hartung, J. 2006 Validation of a method for the detection of virulent Yersinia ...

  17. Direct imaging electron microscopy (EM) methods in modern structural biology: overview and comparison with X-ray crystallography and single-particle cryo-EM reconstruction in the studies of large macromolecules.

    Science.gov (United States)

    Miyaguchi, Katsuyuki

    2014-10-01

    Determining the structure of macromolecules is important for understanding their function. The fine structure of large macromolecules is currently studied primarily by X-ray crystallography and single-particle cryo-electron microscopy (EM) reconstruction. Before the development of these techniques, macromolecular structure was often examined by negative-staining, rotary-shadowing and freeze-etching EM, which are categorised here as 'direct imaging EM methods'. In this review, the results are summarised by each of the above techniques and compared with respect to four macromolecules: the ryanodine receptor, cadherin, rhodopsin and the ribosome-translocon complex (RTC). The results of structural analysis of the ryanodine receptor and cadherin are consistent between each technique. The results obtained for rhodopsin vary to some extent within each technique and between the different techniques. Finally, the results for RTC are inconsistent between direct imaging EM and other analytical techniques, especially with respect to the space within RTC, the reasons for which are discussed. Then, the role of direct imaging EM methods in modern structural biology is discussed. Direct imaging methods should support and verify the results obtained by other analytical methods capable of solving three-dimensional molecular architecture, and they should still be used as a primary tool for studying macromolecule structure in vivo. © 2014 Société Française des Microscopies and Société de Biologie Cellulaire de France. Published by John Wiley & Sons Ltd.

  18. Comparisons of likelihood and machine learning methods of individual classification

    Science.gov (United States)

    Guinand, B.; Topchy, A.; Page, K.S.; Burnham-Curtis, M. K.; Punch, W.F.; Scribner, K.T.

    2002-01-01

    Classification methods used in machine learning (e.g., artificial neural networks, decision trees, and k-nearest neighbor clustering) are rarely used with population genetic data. We compare different nonparametric machine learning techniques with parametric likelihood estimations commonly employed in population genetics for purposes of assigning individuals to their population of origin (“assignment tests”). Classifier accuracy was compared across simulated data sets representing different levels of population differentiation (low and high FST), number of loci surveyed (5 and 10), and allelic diversity (average of three or eight alleles per locus). Empirical data for the lake trout (Salvelinus namaycush) exhibiting levels of population differentiation comparable to those used in simulations were examined to further evaluate and compare classification methods. Classification error rates associated with artificial neural networks and likelihood estimators were lower for simulated data sets compared to k-nearest neighbor and decision tree classifiers over the entire range of parameters considered. Artificial neural networks only marginally outperformed the likelihood method for simulated data (0–2.8% lower error rates). The relative performance of each machine learning classifier improved relative likelihood estimators for empirical data sets, suggesting an ability to “learn” and utilize properties of empirical genotypic arrays intrinsic to each population. Likelihood-based estimation methods provide a more accessible option for reliable assignment of individuals to the population of origin due to the intricacies in development and evaluation of artificial neural networks. In recent years, characterization of highly polymorphic molecular markers such as mini- and microsatellites and development of novel methods of analysis have enabled researchers to extend investigations of ecological and evolutionary processes below the population level to the level of

  19. Numerical simulation and comparison of two ventilation methods for a restaurant - displacement vs mixed flow ventilation

    Science.gov (United States)

    Chitaru, George; Berville, Charles; Dogeanu, Angel

    2018-02-01

    This paper presents a comparison