• Title/Summary/Keyword: Bayes test

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On a Bayes Criterion for the Goodness-of-Link Test for Binary Response Regression Models : Probit Link versus Logit Link

  • Kim, Hea-Jung
    • Journal of the Korean Statistical Society
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    • v.26 no.2
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    • pp.261-276
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    • 1997
  • In the context of binary response regression, the problem of constructing Bayesian goodness-of-link test for testing logit link versus probit link is considered. Based upon the well known facts that cdf of logistic variate .approx. cdf of $t_{8}$/.634 and, as .nu. .to. .infty., cdf of $t_{\nu}$ approximates to that of N(0,1), Bayes factor is derived as a test criterion. A synthesis of the Gibbs sampling and a marginal likelihood estimation scheme is also proposed to compute the Bayes factor. Performance of the test is investigated via Monte Carlo study. The new test is also illustrated with an empirical data example.e.

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A Bayesian Criterion for a Multiple test of Two Multivariate Normal Populations

  • Kim, Hae-Jung;Son, Young-Sook
    • Communications for Statistical Applications and Methods
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    • v.8 no.1
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    • pp.97-107
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    • 2001
  • A simultaneous test criterion for multiple hypotheses concerning comparison of two multivariate normal populations is considered by using the so called Bayes factor method. Fully parametric frequentist approach for the test is not available and thus Bayesian criterion is pursued using a Bayes factor that eliminates its arbitrariness problem induced by improper priors. Specifically, the fractional Bayes factor (FBF) by O'Hagan (1995) is used to derive the criterion. Necessary theories involved in the derivation an computation of the criterion are provided. Finally, an illustrative simulation study is given to show the properties of the criterion.

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Computational procedures for exponential life model incorporating Bayes and shrinkage techniques

  • Al-Hemyari, Zuhair A.;Al-Dabag, H.A.;Al-Humairi, Ali Z.
    • International Journal of Reliability and Applications
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    • v.16 no.2
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    • pp.55-79
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    • 2015
  • It is well known that using any additional information in the estimation of unknown parameters with new sample of observations diminishes the sampling units needed and minimizes the risk of new estimators. There are many rational reasons to assure that the existence of additional information in practice and there exists many practical cases in which additional information is available in the form of target value (initial value) about the unknown parameters. This article is described the problem of how the prior initial value about the unknown parameters can be utilized and combined with classical Bayes estimator to get a new combination of Bayes estimator and prior value to improve the properties of the new combination. In this article, two classes of Bayes-shrinkage and preliminary test Bayes-shrinkage estimators are proposed for the scale parameter of exponential distribution. The bias, risk and risk ratio expressions are derived and studied. The performance of the proposed classes of estimators is studied for different choices of constants engaged in the estimators. The comparisons, conclusions and recommendations are demonstrated.

A Bayes Test for Equality of Intra-Subject Variabilities in 2$\times$2 Crossover Design

  • Oh, Hyun-Sook
    • Communications for Statistical Applications and Methods
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    • v.7 no.2
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    • pp.541-548
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    • 2000
  • Various statistical methods for assessment of equivalence in average bioavailabilities have been developed under the assumption that the intra-subject variabilities for the test and reference formulations are the same. Without the assumption, assessing the equivalence in average bioavailabilites does not imply that the two formulations are therapeutically equivalent and exchangeable. The most commonly used test procedure for equality of variabilites in 2$\times$2 crossover experiment is the so called Pitman-Morgan's adjusted F test based on the model without carryover effects (Chow and Liu(1992)). In this paper, a Bayesian method based on the Intrinsic Bayes Factor is proposed, which can be applied to the model with carryover effects.

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A Bayesian Criterion for a Multiple test of Two Multivariate Normal Populations

  • Kim Hea-Jung;Son Young Sook
    • Proceedings of the Korean Statistical Society Conference
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    • 2000.11a
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    • pp.147-152
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    • 2000
  • A Bayesian criterion is proposed for a multiple test of two independent multivariate normal populations. For a Bayesian test the fractional Bayes facto.(FBF) of O'Hagan(1995) is used under the assumption of Jeffreys priors, noninformative improper proirs. In this test the FBF without the need of sampling minimal training samples is much simpler to use than the intrinsic Bayes facotr(IBF) of Berger and Pericchi(1996). Finally, a simulation study is performed to show the behaviors of the FBF.

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Optimal Convergence Rate of Empirical Bayes Tests for Uniform Distributions

  • Liang, Ta-Chen
    • Journal of the Korean Statistical Society
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    • v.31 no.1
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    • pp.33-43
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    • 2002
  • The empirical Bayes linear loss two-action problem is studied. An empirical Bayes test $\delta$$_{n}$ $^{*}$ is proposed. It is shown that $\delta$$_{n}$ $^{*}$ is asymptotically optimal in the sense that its regret converges to zero at a rate $n^{-1}$ over a class of priors and the rate $n^{-1}$ is the optimal rate of convergence of empirical Bayes tests.sts.

Empirical Bayes Test for the Exponential Parameter with Censored Data

  • Wang, Lichun
    • Communications for Statistical Applications and Methods
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    • v.15 no.2
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    • pp.213-228
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    • 2008
  • Using a linear loss function, this paper considers the one-sided testing problem for the exponential distribution via the empirical Bayes(EB) approach. Based on right censored data, we propose an EB test for the exponential parameter and obtain its convergence rate and asymptotic optimality, firstly, under the condition that the censoring distribution is known and secondly, that it is unknown.

Utterance Verification Using Anti-models Based on Neighborhood Information (이웃 정보에 기초한 반모델을 이용한 발화 검증)

  • Yun, Young-Sun
    • MALSORI
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    • no.67
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    • pp.79-102
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    • 2008
  • In this paper, we investigate the relation between Bayes factor and likelihood ratio test (LRT) approaches and apply the neighborhood information of Bayes factor to building an alternate hypothesis model of the LRT system. To consider the neighborhood approaches, we contemplate a distance measure between models and algorithms to be applied. We also evaluate several methods to improve performance of utterance verification using neighborhood information. Among these methods, the system which adopts anti-models built by collecting mixtures of neighborhood models obtains maximum error rate reduction of 17% compared to the baseline, linear and weighted combination of neighborhood models.

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Robustness of Bayes Test on Dependent Sample

  • Oh, Hyun-Sook
    • Communications for Statistical Applications and Methods
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    • v.4 no.3
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    • pp.787-793
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    • 1997
  • It is well known that the assumption of independence is ofter not valid for real data. This phenomenon has been observed empirically by many prominent scientists. In this article the sensitivity of dependence on Bayes test of a sharp null hypothesis is considered. The robustness is considered with respect to the significant level and the prior probability on the null hypothesis.

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Intrinsic Bayes Factors for Exponential Model Comparison with Censored Data

  • Kim, Dal-Ho;Kang, Sang-Gil;Kim, Seong W.
    • Journal of the Korean Statistical Society
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    • v.29 no.1
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    • pp.123-135
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    • 2000
  • This paper addresses the Bayesian hypotheses testing for the comparison of exponential population under type II censoring. In Bayesian testing problem, conventional Bayes factors can not typically accommodate the use of noninformative priors which are improper and are defined only up to arbitrary constants. To overcome such problem, we use the recently proposed hypotheses testing criterion called the intrinsic Bayes factor. We derive the arithmetic, expected and median intrinsic Bayes factors for our problem. The Monte Carlo simulation is used for calculating intrinsic Bayes factors which are compared with P-values of the classical test.

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