• Title/Summary/Keyword: Gibbs Sampler

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Gibbs Sampling for Double Seasonal Autoregressive Models

  • Amin, Ayman A.;Ismail, Mohamed A.
    • Communications for Statistical Applications and Methods
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    • v.22 no.6
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    • pp.557-573
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    • 2015
  • In this paper we develop a Bayesian inference for a multiplicative double seasonal autoregressive (DSAR) model by implementing a fast, easy and accurate Gibbs sampling algorithm. We apply the Gibbs sampling to approximate empirically the marginal posterior distributions after showing that the conditional posterior distribution of the model parameters and the variance are multivariate normal and inverse gamma, respectively. The proposed Bayesian methodology is illustrated using simulated examples and real-world time series data.

Empirical Statistical Power for Testing Multilocus Genotypic Effects under Unbalanced Designs Using a Gibbs Sampler

  • Lee, Chae-Young
    • Asian-Australasian Journal of Animal Sciences
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    • v.25 no.11
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    • pp.1511-1514
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    • 2012
  • Epistasis that may explain a large portion of the phenotypic variation for complex economic traits of animals has been ignored in many genetic association studies. A Baysian method was introduced to draw inferences about multilocus genotypic effects based on their marginal posterior distributions by a Gibbs sampler. A simulation study was conducted to provide statistical powers under various unbalanced designs by using this method. Data were simulated by combined designs of number of loci, within genotype variance, and sample size in unbalanced designs with or without null combined genotype cells. Mean empirical statistical power was estimated for testing posterior mean estimate of combined genotype effect. A practical example for obtaining empirical statistical power estimates with a given sample size was provided under unbalanced designs. The empirical statistical powers would be useful for determining an optimal design when interactive associations of multiple loci with complex phenotypes were examined.

Inference of Parameters for Superposition with Goel-Okumoto model and Weibull model Using Gibbs Sampler

  • Heecheul Kim
    • Communications for Statistical Applications and Methods
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    • v.6 no.1
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    • pp.169-180
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    • 1999
  • A Markov Chain Monte Carlo method with development of computation is used to be the software system reliability probability model. For Bayesian estimator considering computational problem and theoretical justification we studies relation Markov Chain with Gibbs sampling. Special case of GOS with Superposition for Goel-Okumoto and Weibull models using Gibbs sampling and Metropolis algorithm considered. In this paper discuss Bayesian computation and model selection using posterior predictive likelihood criterion. We consider in this paper data using method by Cox-Lewis. A numerical example with a simulated data set is given.

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Estimation of Genetic Parameters via Gibbs Sampler using Animal Model for Economic Traits in Pigs (Gibbs Sampler를 이용한 돼지 주요 경제형질의 유전모수 추정)

  • Cho, K.H.;Kim, M.J.;Kim, I.C.;Jeon, G.J.
    • Journal of Animal Science and Technology
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    • v.50 no.1
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    • pp.19-26
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    • 2008
  • Heritability and genetic correlation for growth traits in Duroc pig breed were estimated using Bayesian method via Gibbs sampling. The data set consisted of 3,526 performance records at National Institute of Animal Science. For estimating those parameters using Gibbs sampling, 5,000 cycles of ‘burn-in’ period were discarded among a total of 55,000 samples. Out of the remaining 50,000 samples, 5,000 estimates by each parameter were retained and used for analyses to avoid any correlation among adjacent samples. The growth traits considered in this study were average daily gain at 30kg(ADG1), average daily gain at 90kg(ADG2), backfat thickness(BF), days to 90kg(D90) and feed conversion ratio(FC). The estimated heritabilities and their standard deviation using Gibbs sampler were 0.43±0.04, 0.49±0.038, 0.31±0.040, 0.48±0.039 and 0.62±0.086, respectively. Genetic correlations were -0.02, -0.13, -0.55 and -0.15 between ADG1 with ADG2, BF, D90 and FC, respectively, 0.16, -0.73, -0.32 between ADG2 with BF, D90 and FC respectively, 0.01, -0.08 between BF with D90, FC, respectively, and 0.23 between D90 with FC.

Localization Method for Multiple Robots Based on Bayesian Inference in Cognitive Radio Networks (인지 무선 네트워크에서의 베이지안 추론 기반 다중로봇 위치 추정 기법 연구)

  • Kim, Donggu;Park, Joongoo
    • Journal of Institute of Control, Robotics and Systems
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    • v.22 no.2
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    • pp.104-109
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    • 2016
  • In this paper, a localization method for multiple robots based on Bayesian inference is proposed when multiple robots adopting multi-RAT (Radio Access Technology) communications exist in cognitive radio networks. Multiple robots are separately defined by primary and secondary users as in conventional mobile communications system. In addition, the heterogeneous spectrum environment is considered in this paper. To improve the performance of localization for multiple robots, a realistic multiple primary user distribution is explained by using the probabilistic graphical model, and then we introduce the Gibbs sampler strategy based on Bayesian inference. In addition, the secondary user selection minimizing the value of GDOP (Geometric Dilution of Precision) is also proposed in order to overcome the limitations of localization accuracy with Gibbs sampling. Via the simulation results, we can show that the proposed localization method based on GDOP enhances the accuracy of localization for multiple robots. Furthermore, it can also be verified from the simulation results that localization performance is significantly improved with increasing number of observation samples when the GDOP is considered.

A novel Metropolis-within-Gibbs sampler for Bayesian model updating using modal data based on dynamic reduction

  • Ayan Das;Raj Purohit Kiran;Sahil Bansal
    • Structural Engineering and Mechanics
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    • v.87 no.1
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    • pp.1-18
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    • 2023
  • The paper presents a Bayesian Finite element (FE) model updating methodology by utilizing modal data. The dynamic condensation technique is adopted in this work to reduce the full system model to a smaller model version such that the degrees of freedom (DOFs) in the reduced model correspond to the observed DOFs, which facilitates the model updating procedure without any mode-matching. The present work considers both the MPV and the covariance matrix of the modal parameters as the modal data. Besides, the modal data identified from multiple setups is considered for the model updating procedure, keeping in view of the realistic scenario of inability of limited number of sensors to measure the response of all the interested DOFs of a large structure. A relationship is established between the modal data and structural parameters based on the eigensystem equation through the introduction of additional uncertain parameters in the form of modal frequencies and partial mode shapes. A novel sampling strategy known as the Metropolis-within-Gibbs (MWG) sampler is proposed to sample from the posterior Probability Density Function (PDF). The effectiveness of the proposed approach is demonstrated by considering both simulated and experimental examples.

Detecting the Influential Observation Using Intrinsic Bayes Factors

  • Chung, Younshik
    • Journal of the Korean Statistical Society
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    • v.29 no.1
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    • pp.81-94
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    • 2000
  • For the balanced variance component model, sometimes intraclass correlation coefficient is of interest. If there is little information about the parameter, then the reference prior(Berger and Bernardo, 1992) is widely used. Pettit nd Young(1990) considered a measrue of the effect of a single observation on a logarithmic Bayes factor. However, under such a reference prior, the Bayes factor depends on the ratio of unspecified constants. In order to discard this problem, influence diagnostic measures using the intrinsic Bayes factor(Berger and Pericchi, 1996) is presented. Finally, one simulated dataset is provided which illustrates the methodology with appropriate simulation based computational formulas. In order to overcome the difficult Bayesian computation, MCMC methods, such as Gibbs sampler(Gelfand and Smith, 1990) and Metropolis algorithm, are empolyed.

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Bayesian Outlier Detection in Regression Model

  • Younshik Chung;Kim, Hyungsoon
    • Journal of the Korean Statistical Society
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    • v.28 no.3
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    • pp.311-324
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    • 1999
  • The problem of 'outliers', observations which look suspicious in some way, has long been one of the most concern in the statistical structure to experimenters and data analysts. We propose a model for an outlier problem and also analyze it in linear regression model using a Bayesian approach. Then we use the mean-shift model and SSVS(George and McCulloch, 1993)'s idea which is based on the data augmentation method. The advantage of proposed method is to find a subset of data which is most suspicious in the given model by the posterior probability. The MCMC method(Gibbs sampler) can be used to overcome the complicated Bayesian computation. Finally, a proposed method is applied to a simulated data and a real data.

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DEFAULT BAYESIAN INFERENCE OF REGRESSION MODELS WITH ARMA ERRORS UNDER EXACT FULL LIKELIHOODS

  • Son, Young-Sook
    • Journal of the Korean Statistical Society
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    • v.33 no.2
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    • pp.169-189
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    • 2004
  • Under the assumption of default priors, such as noninformative priors, Bayesian model determination and parameter estimation of regression models with stationary and invertible ARMA errors are developed under exact full likelihoods. The default Bayes factors, the fractional Bayes factor (FBF) of O'Hagan (1995) and the arithmetic intrinsic Bayes factors (AIBF) of Berger and Pericchi (1996a), are used as tools for the selection of the Bayesian model. Bayesian estimates are obtained by running the Metropolis-Hastings subchain in the Gibbs sampler. Finally, the results of numerical studies, designed to check the performance of the theoretical results discussed here, are presented.

Bayesian Approach for Determining the Order p in Autoregressive Models

  • Kim, Chansoo;Chung, Younshik
    • Communications for Statistical Applications and Methods
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    • v.8 no.3
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    • pp.777-786
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    • 2001
  • The autoregressive models have been used to describe a wade variety of time series. Then the problem of determining the order in the times series model is very important in data analysis. We consider the Bayesian approach for finding the order of autoregressive(AR) error models using the latent variable which is motivated by Tanner and Wong(1987). The latent variables are combined with the coefficient parameters and the sequential steps are proposed to set up the prior of the latent variables. Markov chain Monte Carlo method(Gibbs sampler and Metropolis-Hasting algorithm) is used in order to overcome the difficulties of Bayesian computations. Three examples including AR(3) error model are presented to illustrate our proposed methodology.

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