• Title/Summary/Keyword: gibbs sampling

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Computing Methods for Generating Spatial Random Variable and Analyzing Bayesian Model (확률난수를 이용한 공간자료가 생성과 베이지안 분석)

  • 이윤동
    • The Korean Journal of Applied Statistics
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    • v.14 no.2
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    • pp.379-391
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    • 2001
  • 본 연구에서는 관심거리가 되고 있는 마코프인쇄 몬테칼로(Markov Chain Monte Carlo, MCMC)방법에 근거한 공간 확률난수 (spatial random variate)생성법과 깁스표본추출법(Gibbs sampling)에 의한 베이지안 분석 방법에 대한 기술적 사항들에 관하여 검토하였다. 먼저 기본적인 확률난수 생성법과 관련된 사항을 살펴보고, 다음으로 조건부명시법(conditional specification)을 이용한 공간 확률난수 생성법을 예를 들어 살펴보기로한다. 다음으로는 이렇게 생성된 공간자료를 분석하기 위하여 깁스표본추출법을 이용한 베이지안 사후분포를 구하는 방법을 살펴보았다.

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Hierarchical Bayes Analysis of Longitudinal Poisson Count Data

  • Kim, Dal-Ho;Shin, Im-Hee;Choi, In-Sun
    • Journal of the Korean Data and Information Science Society
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    • v.13 no.2
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    • pp.227-234
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    • 2002
  • In this paper, we consider hierarchical Bayes generalized linear models for the analysis of longitudinal count data. Specifically we introduce the hierarchical Bayes random effects models. We discuss implementation of the Bayes procedures via Markov chain Monte Carlo (MCMC) integration techniques. The hierarchical Baye method is illustrated with a real dataset and is compared with other statistical methods.

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Bayesian Estimation in Bioequivalence Study

  • Lee, Seung-Chun
    • The Korean Journal of Applied Statistics
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    • v.24 no.6
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    • pp.1095-1102
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    • 2011
  • The classical two-period, two-sequence crossover design is no longer sufficient to assess various demands in a bioequivalence study. For instance, to estimate the within-subject and between-subject variances of test and reference formulations separately, it is necessary to use a replicate design in which each subject receives at least the reference formulation in two periods. Several designs were studied to satisfy the demands. It is provided a unified Bayesian approach applicable to those study designs. The benefit of the method in the bioequivalence study is discussed.

시공간 베이지안 계층모형-미국 연기온 편차자료에 적용-

  • Lee, Ui-Gyu;Mun, Myeong-Sang;Gunst, Richard F.
    • Proceedings of the Korean Statistical Society Conference
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    • 2002.11a
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    • pp.163-168
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    • 2002
  • 전형적인 시공간모형은 시공간 변이도(semivariogram) 또는 공분산 함수(covariance function)를 필요로 한다. 본 논문에서는 계산하기 어렵고 현실적이지 못한 결합 공분산함수를 통한 고전적 모형 대신, 일련의 독립적인 조건분포를 이용하는 보다 현실적인 베이지안 계층모형을 이용한다. 미국 전 지역에 산재해 있는 138개 기온 관측소로부터 얻어진 61년(1920-1980) 동안의 연기온편차 자료에 시공간 베이지안 계층모형을 적용하고 순수시계열모형에서의 적합값과 제안된 모형의 적합값을 비교분석한다.

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Semiparametric Bayesian Estimation under Structural Measurement Error Model

  • Hwang, Jin-Seub;Kim, Dal-Ho
    • Communications for Statistical Applications and Methods
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    • v.17 no.4
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    • pp.551-560
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    • 2010
  • This paper considers a Bayesian approach to modeling a flexible regression function under structural measurement error model. The regression function is modeled based on semiparametric regression with penalized splines. Model fitting and parameter estimation are carried out in a hierarchical Bayesian framework using Markov chain Monte Carlo methodology. Their performances are compared with those of the estimators under structural measurement error model without a semiparametric component.

Bayesian Methods for Combining Results from Different Experiments

  • Lee, In-Suk;Kim, Dal-Ho;Lee, Keun-Baik
    • Communications for Statistical Applications and Methods
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    • v.6 no.1
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    • pp.181-191
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    • 1999
  • We consider Bayesian models allow multiple grouping of parameters for the normal means estimation problem. In particular, we consider a typical Bayesian hierarchical approach based on thepartial exchangeability where the components within a subgroup are exchangeable, but the different subgroups are not. We discuss implementation of such Bayesian procedures via Gibbs sampling. We illustrate the proposed methods with numerical examples.

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Computing Fractional Bayes Factor Using the Generalized Savage-Dickey Density Ratio

  • Younshik Chung;Lee, Sangjeen
    • Journal of the Korean Statistical Society
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    • v.27 no.4
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    • pp.385-396
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    • 1998
  • A computing method of fractional Bayes factor (FBF) for a point null hypothesis is explained. We propose alternative form of FBF that is the product of density ratio and a quantity using the generalized Savage-Dickey density ratio method. When it is difficult to compute the alternative form of FBF analytically, each term of the proposed form can be estimated by MCMC method. Finally, two examples are given.

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Bayesian Estimation for the Reliability of a Multicomponent Stress-Strength System Using Noninformative Priors (비정보 사전분포를 이용한 다중 부품 부하-강도체계의 신뢰도에 대한 베이지안 추정)

  • 김병휘;장인홍
    • Proceedings of the Korean Reliability Society Conference
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    • 2000.11a
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    • pp.411-411
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    • 2000
  • Consider the problem of estimating the reliability of a multicomponent stress-strength system which functions if at least r of the k identical components simultaneously function. All stresses and strengths are assumed to be independent random variables with two parameter Weibull distributions. First, we derive reference priors and probability matching priors which are noninformative priors. We next investigate sufficient conditions for propriety of posteriors under reference priors and probability matching priors. Finally, we provide, using these priors, some numerical results for Bayes estimates of the reliability by applying Gibbs sampling technique.

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A study of user's anomalous behavior analysis using Bayesian Network and integrated audit data (베이지안 네트워크와 통합 감사 자료를 이용한 사용자의 비정상행위 탐지에 관한 연구)

  • 정일안;노봉남
    • Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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    • 2001.11a
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    • pp.269-272
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    • 2001
  • 본 논문에서는 베이지안 네트워크와 통합 감사자료를 이용하여 시스템 사용자에 대한 비정상행위를 탐지하고 분석하는데 효과적인 모델을 제안하고자 한다. 이를 위해 리눅스 시스템에서의 여러 가지 감사자료들을 통합한 감사자료로부터 사용자의 행위에 대해 베이지안 네트워크로 구성하고자 한다. 베이지안 네트워크를 구성할 때 효율적인 학습이 가능한 Sparse Candidate 알고리즘을 적용하고, 감사자료의 일부가 결여되어 있는 경우에도 추론이 가능하도록 MCMC(Markov Chain Monte Carlo)의 일종인 Gibbs Sampling 방법을 적용한다.

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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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    • v.2 no.2
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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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