• Title/Summary/Keyword: Sample testing

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MINITAB Macros for Testing the Difference of Mean Vectors of Two Multivariate Populations

  • Hyuk Joo;Min Ah
    • Communications for Statistical Applications and Methods
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    • v.7 no.1
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    • pp.179-198
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    • 2000
  • We consider the problem of comparing the mean vectors of two multivaiate populations, We focus on testing hypotheses concerning two multivariate mean vectors by use of MINITAB, For the cases of small sample and large sample MINITAB programs and outputs are presented for solving staistical problems. The MiniTAB programs made in this paper are saved as macro files and thus can be conveniently used for solving another problems.

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The Bahadur Efficiency of the Power-Divergence Statistics Conditional on Margins for Testing homogeneity with Equal Sample Size

  • Kang, Seung-Ho
    • Journal of the Korean Statistical Society
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    • v.26 no.4
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    • pp.453-465
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    • 1997
  • The family of power-divergence statistics conditional on margins is considered for testing homogeneity of .tau. multinomial populations with equal sample size and the exact Bahadur slope is obtained. It is shown that the likelihood ratio test conditional on margins is the most Bahadur efficient among the family of power-divergence statistics.

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A Bayes Criterion for Testing Homogeneity of Two Multivariate Normal Covariances

  • Kim, Hea-Jung
    • Journal of the Korean Statistical Society
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    • v.27 no.1
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    • pp.11-23
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    • 1998
  • A Bayes criterion for testing the equality of covariance matrices of two multivariate normal distributions is proposed and studied. Development of the criterion invloves calculation of Bayes factor using the imaginary sample method introduced by Spiegelhalter and Smith (1982). The criterion is designed to develop a Bayesian test criterion, so that it provides an alternative test criterion to those based upon asymptotic sampling theory (such as Box's M test criterion). For the constructed criterion, numerical studies demonstrate routine application and give comparisons with the traditional test criteria.

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Review of Nonparametric Statistics by Neyman-Pearson Test and Fisher Test (Neyman-Pearson 검정과 Fisher 검정에 의한 비모수 통계의 고찰)

  • Choi, Sung-Woon
    • Proceedings of the Safety Management and Science Conference
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    • 2008.04a
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    • pp.451-460
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    • 2008
  • This paper reviews nonparametric statistics by Neyman-Pearson test and Fisher test. Nonparametric statistics deal with the small sample with distribution-free assumption in multi-product and small-volume production. Two tests for various nonparametric statistic methods such as sign test, Wilcoxon test, Mann-Whitney test, Kruskal-Wallis test, Mood test, Friedman test and run test are also presented with the steps for testing hypotheses and test of significance.

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Equivalence testing and its applications in industry (공업통계분야에서 동등성 검정 및 그 응용)

  • Baik, Jai-Wook
    • Journal of Korean Society for Quality Management
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    • v.36 no.4
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    • pp.1-6
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    • 2008
  • As more and more data are collected one may ask whether the data collected within a short period of time are same. In this case traditional hypothesis testing of $H_o:{\mu}_1={\mu}_2$ vs $H_1:{\mu}_1{\neq}{\mu}_2$ is used to determine whether the data are same when there is no knowledge about equivalence testing. However, this type of hypothesis testing has the undesirable property of penalizing higher precision. So TOST is to be performed in the event of equivalence testing. In this study equivalence testing is introduced where one can find the applications in industry. Traditional two sample t testing is to be compared with the equivalent testing and the procedure to perform the equivalence testing is to be presented along with an example. Finally equivalence testing in terms of the other parameters such as variance, proportion or failure rate is to be sought.

WS-I Sample Application Implementation Experience

  • Seok, Gwang-Jin
    • 한국IT서비스학회:학술대회논문집
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    • 2003.11a
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    • pp.822-840
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    • 2003
  • The Basic Profile has helped interoperability. Sample Application experience is already reflected in a most major platforms. Usage Scenarios valuable in identifying where BP restrictions apply. Testing is critical.

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Kolmogorov-Smirnov Type Test for Change with Sample Fourier Coefficients

  • Kim, Jae-Hee
    • Journal of the Korean Statistical Society
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    • v.25 no.1
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    • pp.123-131
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    • 1996
  • The problerm of testing for a constant mean is considered. A Kolmogorov-Smirnov type test using the sample Fourier coefficients is suggested and its asymptotic distribution is derived. A simulation study shows that the proposed test is more powerful than the cusum type test when there is more than one change-point or there is a cyclic change.

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Evaluation for the Sensory Quality of Commercial Soymilk (시판 두유의 품질에 대한 관능적 측정)

  • 표영희;안명수
    • Korean journal of food and cookery science
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    • v.3 no.2
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    • pp.81-86
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    • 1987
  • The quality for flavor-by-mouth of commercial soymilk was evaluated by sensory testing. The results were summerized as follows : 1. A significant difference on the sweety flavor of sample I was recognized at In level among the rest of samples except sample B. 2. A significant difference on the thick and the nutty flavor of sample C was recognized at In level among the each samples. Therefore sample C, generally recognized as having thick and nutty flavor. 3. A significant difference on the benny flavor was not recognized at 5n level among the samples of commercial soymilk. 4. According to the results of sensory testing for commercial soymilk, the sweety flavor of the each sample was generally evaluated as common flavor except sample C.

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Sample Size and Statistical Power Calculation in Genetic Association Studies

  • Hong, Eun-Pyo;Park, Ji-Wan
    • Genomics & Informatics
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    • v.10 no.2
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    • pp.117-122
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    • 2012
  • A sample size with sufficient statistical power is critical to the success of genetic association studies to detect causal genes of human complex diseases. Genome-wide association studies require much larger sample sizes to achieve an adequate statistical power. We estimated the statistical power with increasing numbers of markers analyzed and compared the sample sizes that were required in case-control studies and case-parent studies. We computed the effective sample size and statistical power using Genetic Power Calculator. An analysis using a larger number of markers requires a larger sample size. Testing a single-nucleotide polymorphism (SNP) marker requires 248 cases, while testing 500,000 SNPs and 1 million markers requires 1,206 cases and 1,255 cases, respectively, under the assumption of an odds ratio of 2, 5% disease prevalence, 5% minor allele frequency, complete linkage disequilibrium (LD), 1:1 case/control ratio, and a 5% error rate in an allelic test. Under a dominant model, a smaller sample size is required to achieve 80% power than other genetic models. We found that a much lower sample size was required with a strong effect size, common SNP, and increased LD. In addition, studying a common disease in a case-control study of a 1:4 case-control ratio is one way to achieve higher statistical power. We also found that case-parent studies require more samples than case-control studies. Although we have not covered all plausible cases in study design, the estimates of sample size and statistical power computed under various assumptions in this study may be useful to determine the sample size in designing a population-based genetic association study.

Investigation of shear behavior of soil-concrete interface

  • Haeri, Hadi;Sarfarazi, Vahab;Zhu, Zheming;Marji, Mohammad Fatehi;Masoumi, Alireza
    • Smart Structures and Systems
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    • v.23 no.1
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    • pp.81-90
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    • 2019
  • The shear behavior of soil-concrete interface is mainly affected by the surface roughness of the two contact surfaces. The present research emphasizes on investigating the effect of roughness of soil-concrete interface on the interface shear behavior in two-layered laboratory testing samples. In these specially prepared samples, clay silt layer with density of $2027kg/m^3$ was selected to be in contact a concrete layer for simplifying the laboratory testing. The particle size testing and direct shear tests are performed to determine the appropriate particles sizes and their shear strength properties such as cohesion and friction angle. Then, the surface undulations in form of teeth are provided on the surfaces of both concrete and soil layers in different testing carried out on these mixed specimens. The soil-concrete samples are prepared in form of cubes of 10*10*30 cm. in dimension. The undulations (inter-surface roughness) are provided in form of one tooth or two teeth having angles $15^{\circ}$ and $30^{\circ}$, respectively. Several direct shear tests were carried out under four different normal loads of 80, 150, 300 and 500 KPa with a constant displacement rate of 0.02 mm/min. These testing results show that the shear failure mechanism is affected by the tooth number, the roughness angle and the applied normal stress on the sample. The teeth are sheared from the base under low normal load while the oblique cracks may lead to a failure under a higher normal load. As the number of teeth increase the shear strength of the sample also increases. When the tooth roughness angle increases a wider portion of the tooth base will be failed which means the shear strength of the sample is increased.