• 제목/요약/키워드: Gibbs priors

검색결과 35건 처리시간 0.019초

Bayesian Multiple Comparisons for Normal Variances

  • Kim, Hea-Jung
    • Journal of the Korean Statistical Society
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    • 제29권2호
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    • pp.155-168
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    • 2000
  • Regarding to multiple comparison problem (MCP) of k normal population variances, we suggest a Bayesian method for calculating posterior probabilities for various hypotheses of equality among population variances. This leads to a simple method for obtaining pairwise comparisons of variances in a statistical experiment with a partition on the parameter space induced by equality and inequality relationships among the variances. The method is derived from the fact that certain features of the hierarchical nonparametric family of Dirichlet process priors, in general, make it amenable to solving the MCP and estimating the posterior probabilities by means of posterior simulation, the Gibbs sampling. Two examples are illustrated for the method. For these examples, the method is straightforward for specifying distributionally and to implement computationally, with output readily adapted for required comparison.

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Nonparametric Bayesian Multiple Comparisons for Dependence Parameter in Bivariate Exponential Populations

  • 조장식
    • 한국데이터정보과학회:학술대회논문집
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    • 한국데이터정보과학회 2006년도 추계 학술발표회 논문집
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    • pp.71-80
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    • 2006
  • A nonparametric Bayesian multiple comparisons problem (MCP) for dependence parameters in I bivariate exponential populations is studied here. A simple method for pairwise comparisons of these parameters is also suggested. Here we extend the methodology studied by Gopalan and Berry (1998) using Dirichlet process priors. The family of Dirichlet process priors is applied in the form of baseline prior and likelihood combination to provide the comparisons. Computation of the posterior probabilities of all possible hypotheses are carried out through Markov Chain Monte Carlo method, namely, Gibbs sampling, due to the intractability of analytic evaluation. The whole process of MCP for the dependent parameters of bivariate exponential populations is illustrated through a numerical example.

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Robust Bayesian Analysis in Finite Population Sampling with Auxiliary Information

  • Lee, Seung-A;Suh, Sang-Hyuck;Kim, Dal-Ho
    • Journal of the Korean Data and Information Science Society
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    • 제17권4호
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    • pp.1309-1317
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    • 2006
  • The paper considers some Bayes estimators of the finite population mean with auxiliary information under priors which are scale mixtures of normal, and thus have tail heavier than that of the normal. The proposed estimators are quite robust in general. Numerical methods of finding Bayes estimators under these heavy tailed priors are given, and are illustrated with an actual example.

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Bayesian Estimation via the Griddy Gibbs Sampling for the Laplacian Autoregressive Time Series Model

  • Young Sook Son;Sinsup Cho
    • Communications for Statistical Applications and Methods
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    • 제2권2호
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    • pp.115-125
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    • 1995
  • This paper deals with the Bayesian estimation for the NLAR(1) model with Laplacian marginals. Assuming the independent uniform priors for two parameters of the NLAT(1) model, the griddy Gbbs sampler by Ritter and Tanner(1992) is used to obtain the Bayesian estimates. Random numbers generated form the uniform priors ate used as the grids for each parameter. Some simulations are conducted and compared with the maximum likelihood estimation result.

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Robust Bayesian Models for Meta-Analysis

  • Kim, Dal-Ho;Park, Gea-Joo
    • Journal of the Korean Data and Information Science Society
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    • 제11권2호
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    • pp.313-318
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    • 2000
  • This article addresses aspects of combining information, with special attention to meta-analysis. In specific, we consider hierarchical Bayesian models for meta-analysis under priors which are scale mixtures of normal, and thus have tail heavier than that of the normal. Numerical methods of finding Bayes estimators under these heavy tailed prior are given, and are illustrated with an actual example.

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Semiparametric Bayesian multiple comparisons for Poisson Populations

  • Cho, Jang Sik;Kim, Dal Ho;Kang, Sang Gil
    • Communications for Statistical Applications and Methods
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    • 제8권2호
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    • pp.427-434
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    • 2001
  • In this paper, we consider the nonparametric Bayesian approach to the multiple comparisons problem for I Poisson populations using Dirichlet process priors. We describe Gibbs sampling algorithm for calculating posterior probabilities for the hypotheses and calculate posterior probabilities for the hypotheses using Markov chain Monte Carlo. Also we provide a numerical example to illustrate the developed numerical technique.

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Bayesian Parameter Estimation using the MCMC method for the Mean Change Model of Multivariate Normal Random Variates

  • Oh, Mi-Ra;Kim, Eoi-Lyoung;Sim, Jung-Wook;Son, Young-Sook
    • Communications for Statistical Applications and Methods
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    • 제11권1호
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    • pp.79-91
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    • 2004
  • In this thesis, Bayesian parameter estimation procedure is discussed for the mean change model of multivariate normal random variates under the assumption of noninformative priors for all the parameters. Parameters are estimated by Gibbs sampling method. In Gibbs sampler, the change point parameter is generated by Metropolis-Hastings algorithm. We apply our methodology to numerical data to examine it.

Bayes tests of independence for contingency tables from small areas

  • Jo, Aejung;Kim, Dal Ho
    • Journal of the Korean Data and Information Science Society
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    • 제28권1호
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    • pp.207-215
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    • 2017
  • In this paper we study pooling effects in Bayesian testing procedures of independence for contingency tables from small areas. In small area estimation setup, we typically use a hierarchical Bayesian model for borrowing strength across small areas. This techniques of borrowing strength in small area estimation is used to construct a Bayes test of independence for contingency tables from small areas. In specific, we consider the methods of direct or indirect pooling in multinomial models through Dirichlet priors. We use the Bayes factor (or equivalently the ratio of the marginal likelihoods) to construct the Bayes test, and the marginal density is obtained by integrating the joint density function over all parameters. The Bayes test is computed by performing a Monte Carlo integration based on the method proposed by Nandram and Kim (2002).

Nonparametric Bayesian Multiple Comparisons for Geometric Populations

  • Ali, M. Masoom;Cho, J.S.;Begum, Munni
    • Journal of the Korean Data and Information Science Society
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    • 제16권4호
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    • pp.1129-1140
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    • 2005
  • A nonparametric Bayesian method for calculating posterior probabilities of the multiple comparison problem on the parameters of several Geometric populations is presented. Bayesian multiple comparisons under two different prior/ likelihood combinations was studied by Gopalan and Berry(1998) using Dirichlet process priors. In this paper, we followed the same approach to calculate posterior probabilities for various hypotheses in a statistical experiment with a partition on the parameter space induced by equality and inequality relationships on the parameters of several geometric populations. This also leads to a simple method for obtaining pairwise comparisons of probability of successes. Gibbs sampling technique was used to evaluate the posterior probabilities of all possible hypotheses that are analytically intractable. A numerical example is given to illustrate the procedure.

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A Bayesian model for two-way contingency tables with nonignorable nonresponse from small areas

  • Woo, Namkyo;Kim, Dal Ho
    • Journal of the Korean Data and Information Science Society
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    • 제27권1호
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    • pp.245-254
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    • 2016
  • Many surveys provide categorical data and there may be one or more missing categories. We describe a nonignorable nonresponse model for the analysis of two-way contingency tables from small areas. There are both item and unit nonresponse. One approach to analyze these data is to construct several tables corresponding to missing categories. We describe a hierarchical Bayesian model to analyze two-way categorical data from different areas. This allows a "borrowing of strength" of the data from larger areas to improve the reliability in the estimates of the model parameters corresponding to the small areas. Also we use a nonignorable nonresponse model with Bayesian uncertainty analysis by placing priors in nonidentifiable parameters instead of a sensitivity analysis for nonidentifiable parameters. We use the griddy Gibbs sampler to fit our models and compute DIC and BPP for model diagnostics. We illustrate our method using data from NHANES III data on thirteen states to obtain the finite population proportions.