• Title/Summary/Keyword: null test

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On Flexible Bayesian Test Criteria for Nested Point Null Hypotheses of Multiple Regression Coefficients

  • Jae-Hyun Kim;Hea-Jung Kim
    • Communications for Statistical Applications and Methods
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    • v.3 no.3
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    • pp.205-214
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    • 1996
  • As flexible Bayesian test criteria for nested point null hypotheses of multiple regression coefficients, partial and overall Bayes factors are introduced under a class of intuitively meaningful prior. The criteria lead to a simple method for considering different prior beliefs on the subspaces that constitute a partition of the coefficient parameter space. A couple of tests are suggested based on the criteria. It is shown that they enable us to obtain pairwise comparisons of hypotheses of the partitioned subspaces. Through a Monte Carlo simulation, performance of the tests based on the criteria are compared with the usual Bayesian test (based on Bayes factor)in terms of their respective powers.

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Multivariate Nonparametric Tests for Grouped and Right Censored Data

  • Park Hyo-Il;Na Jong-Hwa;Hong Seungman
    • International Journal of Reliability and Applications
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    • v.6 no.1
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    • pp.53-64
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    • 2005
  • In this paper, we propose a nonparametric test procedure for the multivariate, grouped and right censored data for two sample problem. For the construction of the test statistic, we use the linear rank statistics for each component and apply the permutation principle for obtaining the null distribution. For the large sample case, the asymptotic distribution is derived under the null hypothesis with the additional assumption that two censoring distributions are also equal. Finally, we illustrate our procedure with an example and discuss some concluding remarks. In appendices, we derive the expression of the covariance matrix and prove the asymptotic distribution.

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A Two Sample Test for Functional Data

  • Lee, Jong Soo;Cox, Dennis D.;Follen, Michele
    • Communications for Statistical Applications and Methods
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    • v.22 no.2
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    • pp.121-135
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    • 2015
  • We consider testing equality of mean functions from two samples of functional data. A novel test based on the adaptive Neyman methodology applied to the Hotelling's T-squared statistic is proposed. Under the enlarged null hypothesis that the distributions of the two populations are the same, randomization methods are proposed to find a null distribution which gives accurate significance levels. An extensive simulation study is presented which shows that the proposed test works very well in comparison with several other methods under a variety of alternatives and is one of the best methods for all alternatives, whereas the other methods all show weak power at some alternatives. An application to a real-world data set demonstrates the applicability of the method.

A Vehicle SoC Fault Diagnosis Technique using FlexRay Protocol

  • Kang, Seung-Yeop;Jung, Ji-Hun;Park, Sung-Ju
    • Journal of the Korea Society of Computer and Information
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    • v.21 no.1
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    • pp.39-47
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    • 2016
  • In this paper, we propose vehicle SoC fault diagnosis platform using FlexRay protocol in order to detect the faults of semiconductor control chip even after vehicle production. Before FlexRay protocol by sending NFI (Null Frame Indicator) bit among the header segment and a specific identifier in the payload segment of FlexRay frame, this technique can be distinguishable from normal mode and test mode. By using this technique, it is possible to detect the faults such as performance degradation of vehicle network system caused by the aging or several problems of vehicle semiconductor chip. Also high reliability and safety of vehicle can be maintained by using structural test for vehicle SoC fault detection.

Nonparametric Test Procedures for Change Point Problems in Scale Parameter

  • Cho, Wan-Hyun;Lee, Jae-Chang
    • Journal of the Korean Statistical Society
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    • v.19 no.2
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    • pp.128-138
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    • 1990
  • In this paper we study the properties of nonparametric tests for testing the null hypothesis of no changes against one sided and two sideds alternatives in scale parameter at unknown point. We first propose two types of nonparametric tests based on linear rank statistics and rank-like statistics, respectively. For these statistics, we drive the asymptotic distributions under the null and contiguous alternatives. The main theoreticla tools used for derivation are the stochastic process representation of the test staistic and the Brownian bridge approximation. We evaluate the Pitman efficiencies of the test for the contiguous alternatives, and also compute empirical power by Monte Carlo simulation.

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Comparative Analysis of Two Independent Proportions in Non-Inferiority Trials (비열등성 임상시험에서 독립인 두 비율 차 검정에 대한 비교 연구)

  • Yoon, Min;Kwak, Min-Jung
    • The Korean Journal of Applied Statistics
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    • v.23 no.6
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    • pp.1115-1124
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    • 2010
  • Normal approximation methods under the null hypothesis of no difference are frequently used to test the two independent proportions in non-inferiority trials. However, these tests are not appropriate under the null hypothesis of non-zero difference. We review the likelihood score methods proposed by Miettinen and Nurminen, Farrington and Manning, and Gart and Nam and compare the performance of these tests. The simulation study shows that the likelihood score tests under the null hypothesis of non-zero difference have better performance at a Type I error and power than usual normal approximation methods.

선진광학기술, 이론과 실습 동시에 익힌 뜻깊은 기회

  • 박종영
    • The Optical Journal
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    • v.11 no.5 s.63
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    • pp.65-69
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    • 1999
  • 한국광학기기협회가 '한$\cdot$일 광학산업 기술협력 사업'의 일환으로 주관한 일본 히다카(日高)광학연구소 연수를 통해 Focult Test, Null Test, Ronchi Test 등 다양한 렌즈 검사 방법과 비구면 렌즈 가공방법을 실습과 이론을 겸해서 익혔다. 우리 나라도 렌즈 가공, 검사 방법 등에 대한 실무와 이론체계를 확실히 정립해야 할 때임을 절실히 느낄 수 있는 기회였다.

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Testing Homogeneity for Random Effects in Linear Mixed Model

  • Ahn, Chul H.
    • Communications for Statistical Applications and Methods
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    • v.7 no.2
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    • pp.403-414
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    • 2000
  • A diagnostic tool for testing homogeneity for random effects is proposed in unbalanced linear mixed model based on score statistic. The finite sample behavior of the test statistic is examined using Monte Carlo experiments examine the chi-square approximation of the test statistic under the null hypothesis.

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Test of Independence in a Markov Dependent Waiting-time Distribution

  • Bai, Do-Sun
    • Journal of Korean Institute of Industrial Engineers
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    • v.1 no.1
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    • pp.99-103
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    • 1975
  • A procedure for the test of independence of the observations and the null distribution are studied for a waiting-time distribution of the number of Bernoulli trials required to obtain a preassigned number of successes under Markov dependence. Selected critical values for the test statistic are tabulated.

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Testing Homogeneity of Errors in Unbalanced Random Effects Linear Model

  • Ahn, Chul H.
    • Communications for Statistical Applications and Methods
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    • v.8 no.3
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    • pp.603-613
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    • 2001
  • A test based on score statistic is derived for detecting homoscedasticity of errors in unbalanced random effects linear model. A small simulation study is performed to investigate the finite sample behaviour of the test statistic which is known to have an asymptotic chi-square distribution under the null hypothesis.

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