• Title/Summary/Keyword: union-intersection principle

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Test procedures for the mean and variance simultaneously under normality

  • Park, Hyo-Il
    • Communications for Statistical Applications and Methods
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    • v.23 no.6
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    • pp.563-574
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    • 2016
  • In this study, we propose several simultaneous tests to detect the difference between means and variances for the two-sample problem when the underlying distribution is normal. For this, we apply the likelihood ratio principle and propose a likelihood ratio test. We then consider a union-intersection test after identifying the likelihood statistic, a product of two individual likelihood statistics, to test the individual sub-null hypotheses. By noting that the union-intersection test can be considered a simultaneous test with combination function, also we propose simultaneous tests with combination functions to combine individual tests for each sub-null hypothesis. We apply the permutation principle to obtain the null distributions. We then provide an example to illustrate our proposed procedure and compare the efficiency among the proposed tests through a simulation study. We discuss some interesting features related to the simultaneous test as concluding remarks. Finally we show the expression of the likelihood ratio statistic with a product of two individual likelihood ratio statistics.

Robust Inference for Testing Order-Restricted Inference

  • Kang, Moon-Su
    • The Korean Journal of Applied Statistics
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    • v.22 no.5
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    • pp.1097-1102
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    • 2009
  • Classification of subjects with unknown distribution in small sample size setup may involve order-restricted constraints in multivariate parameter setups. Those problems makes optimality of conventional likelihood ratio based statistical inferences not feasible. Fortunately, Roy (1953) introduced union-intersection principle(UIP) which provides an alternative avenue. Redescending M-estimator along with that principle yields a considerably appropriate robust testing procedure. Furthermore, conditionally distribution-free test based upon exact permutation theory is used to generate p-values, even in small sample. Applications of this method are illustrated in simulated data and read data example (Lobenhofer et al., 2002)

Robust inference with order constraint in microarray study

  • Kang, Joonsung
    • Communications for Statistical Applications and Methods
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    • v.25 no.5
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    • pp.559-568
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    • 2018
  • Gene classification can involve complex order-restricted inference. Examining gene expression pattern across groups with order-restriction makes standard statistical inference ineffective and thus, requires different methods. For this problem, Roy's union-intersection principle has some merit. The M-estimator adjusting for outlier arrays in a microarray study produces a robust test statistic with distribution-insensitive clustering of genes. The M-estimator in conjunction with a union-intersection principle provides a nonstandard robust procedure. By exact permutation distribution theory, a conditionally distribution-free test based on the proposed test statistic generates corresponding p-values in a small sample size setup. We apply a false discovery rate (FDR) as a multiple testing procedure to p-values in simulated data and real microarray data. FDR procedure for proposed test statistics controls the FDR at all levels of ${\alpha}$ and ${\pi}_0$ (the proportion of true null); however, the FDR procedure for test statistics based upon normal theory (ANOVA) fails to control FDR.

Order-Restricted Inference with Linear Rank Statistics in Microarray Data

  • Kang, Moon-Su
    • The Korean Journal of Applied Statistics
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    • v.24 no.1
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    • pp.137-143
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    • 2011
  • The classification of subjects with unknown distribution in a small sample size often involves order-restricted constraints in multivariate parameter setups. Those problems make the optimality of a conventional likelihood ratio based statistical inferences not feasible. Fortunately, Roy (1953) introduced union-intersection principle(UIP) which provides an alternative avenue. Multivariate linear rank statistics along with that principle, yield a considerably appropriate robust testing procedure. Furthermore, conditionally distribution-free test based upon exact permutation theory is used to generate p-values, even in a small sample. Applications of this method are illustrated in a real microarray data example (Lobenhofer et al., 2002).

Remarks on the Use of Multivariate Skewness and Kurtosis for Testing Multivariate Normality (정규성 검정을 위한 다변량 왜도와 첨도의 이용에 대한 고찰)

  • 김남현
    • The Korean Journal of Applied Statistics
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    • v.17 no.3
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    • pp.507-518
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    • 2004
  • Malkovich & Afifi (1973) generalized the univariate skewness and kurtosis to test a hypothesis of multivariate normality by use of the union-intersection principle. However these statistics are hard to compute for high dimensions. We propose the approximate statistics to them, which are practical for a high dimensional data set. We also compare the proposed statistics to Mardia(1970)'s multivariate skewness and kurtosis by a Monte Carlo study.

Operations of fuzzy bags

  • Kim, Kyung-Soo;Miyamoto, Sadaaki
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10a
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    • pp.28-31
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    • 1996
  • A bag is a set-like entity which can contain repeated elements. Fuzzy bags have been studied by Yager, who defined their basic relations and operations. However, his definitions of the basic relations and operations are inconsistent with the corresponding relations and operations for ordinary fuzzy sets. The present paper presents new basic relations and operations of fuzzy bags using a grade sequence for each element of the universal set. Moreover the .alpha.-cut, t-norms, the extension principle, and the composition of fuzzy bag relations are described.

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Testing Multivariate Normality Based on EDF Statistics (EDF 통계량을 이용한 다변량 정규성검정)

  • Kim Nam-Hyun
    • The Korean Journal of Applied Statistics
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    • v.19 no.2
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    • pp.241-256
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    • 2006
  • We generalize the $Cram{\acute{e}}r$-von Mises Statistic to test multivariate normality using Roy's union-intersection principle. We show the limit distribution of the suggested statistic is representable as the integral of a suitable Gaussian process. We also consider the computational aspects of the proposed statistic. Power performance is assessed in a Monte Carlo study.