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Skew-normal distribution is a class of distributions that includes the normal distributions as a special case. In this paper, we explore the use of Markov Chain Monte Carlo (MCMC) methods to develop a Bayesian analysis in a multivariate, null intercept, measurement error model [R. Aoki, H. Bolfarine, J.A. Achcar, and D. Leao Pinto Jr, Bayesian analysis of a multivariate null intercept error-in-variables regression model, J. Biopharm. Stat. 13(4) (2003b), pp. 763-771] where the unobserved value of the covariate (latent variable) follows a skew-normal distribution. The results and methods are applied to a real dental clinical trial presented in [A. Hadgu and G. Koch, Application of generalized estimating equations to a dental randomized clinical trial, J. Biopharm. Stat. 9 (1999), pp. 161-178]. [ABSTRACT FROM AUTHOR]

This paper proposes a procedure of synthetic detection for the location of a change point and outliers in bilinear time series models with a change after an unknown time point. Based on Bayesian framework, we first derive the conditional posterior distribution of the change point and from that distribution estimate the position of the change point. Then we use these results to detect the outliers in the time series before and after that change point via Gibbs sampler algorithm. Our simulation studies show that the proposed procedure is effective. [ABSTRACT FROM PUBLISHER]

In this paper zero-inflated distributions (ZID) are studied from the Bayesian point of view using the data augmentation algorithm. This type of discrete model arises in count data with excess of zeros. The zero-inflated Poisson distribution (ZIP) and an illustrative example via MCMC algorithm are considered. [ABSTRACT FROM AUTHOR]

Motivated by molecular biology, there has been an upsurge of research activities in directional statistics in general and its Bayesian aspect in particular. The central distribution for the circular case is von Mises distribution which has two parameters (mean and concentration) akin to the univariate normal distribution. However, there has been a challenge to sample efficiently from the posterior distribution of the concentration parameter. We describe a novel, highly efficient algorithm to sample from the posterior distribution and fill this long-standing gap. [ABSTRACT FROM AUTHOR]

It is well known that the approximate Bayesian computation algorithm based on Markov chain Monte Carlo methods suffers from the sensitivity to the choice of starting values, inefficiency and a low acceptance rate. To overcome these problems, this study proposes a generalization of the multiple-point Metropolis algorithm, which proceeds by generating multiple-dependent proposals and then by selecting a candidate among the set of proposals on the basis of weights that can be chosen arbitrarily. The performance of the proposed algorithm is illustrated by using both simulated and real data. [ABSTRACT FROM AUTHOR]

This article develops an algorithm for estimating parameters of general phase-type (PH) distribution based on Bayes estimation. The idea of Bayes estimation is to regard parameters as random variables, and the posterior distribution of parameters which is updated by the likelihood function provides estimators of parameters. One of the advantages of Bayes estimation is to evaluate uncertainty of estimators. In this article, we propose a fast algorithm for computing posterior distributions approximately, based on variational approximation. We formulate the optimal variational posterior distributions for PH distributions and develop the efficient computation algorithm for the optimal variational posterior distributions of discrete and continuous PH distributions. [ABSTRACT FROM AUTHOR]

Latent class models (LCMs) are specific cases of mixture models. Under a Bayesian setup, the symmetric posterior distribution of these models leads Markov chain Monte Carlo (MCMC) methods to suffer from the so-called label switching problem. In this article, we treat the corresponding MCMC outputs using a recent approach, namely, the Equivalence Classes Representative (ECR) algorithm and conclude that it can effectively solve the label switching problem by considering several examples of LCMs, such as mixtures of regressions, hidden Markov models, and Markov random fields. Moreover, the superiority of this method over other approaches becomes apparent. [ABSTRACT FROM PUBLISHER]

Solving label switching is crucial for interpreting the results of fitting Bayesian mixture models. The label switching originates from the invariance of posterior distribution to permutation of component labels. As a result, the component labels in Markov chain simulation may switch to another equivalent permutation, and the marginal posterior distribution associated with all labels may be similar and useless for inferring quantities relating to each individual component. In this article, we propose a new simple labelling method by minimizing the deviance of the class probabilities to a fixed reference labels. The reference labels can be chosen before running Markov chain Monte Carlo (MCMC) using optimization methods, such as expectation-maximization algorithms, and therefore the new labelling method can be implemented by an online algorithm, which can reduce the storage requirements and save much computation time. Using the Acid data set and Galaxy data set, we demonstrate the success of the proposed labelling method for removing the labelling switching in the raw MCMC samples. [ABSTRACT FROM PUBLISHER]

From the exact distribution of the maximum likelihood estimator of the average lifetime based on progressive hybrid exponential censored sample, we derive an explicit expression for the Bayes risk of a sampling plan when a quadratic loss function is used. The simulated annealing algorithm is then used to determine the optimal sampling plan. Some optimal Bayes solutions under progressive hybrid and ordinary hybrid censoring schemes are presented to illustrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Bayesian model selection depends on the integrated likelihood of the data given the model. Newton and Raftery's harmonic mean estimator (HME) is simple to implement by computing the likelihood of the data at MCMC draws from the posterior distribution. Alternative methods in the literature require additional simulations or more extensive computations. In theory HME is consistent but can have an infinite variance. In practice, the computed HME often is simulation pseudo-biased. This article identifies the source of the pseudo-bias and recommends several algorithms for adjusting the HME to remove it. The pseudo-bias can be substantial and can negatively affect HME's ability to select the correct model in Bayesian model selection. The pseudo-bias often causes the computed HME to overestimate the integrated likelihood, and the amount of pseudo-bias tends to be larger for more complex models. When the computed HME errs, it tends to select models that are too complex. Simulation studies of linear and logistic regression models demonstrate that the adjusted HME effectively removes the pseudo-bias, is more accurate, and indicates more reliably the best model. Supplemental materials are available online. These materials include the appendices and Gauss program. [ABSTRACT FROM AUTHOR]

Model search in probit regression is often conducted by simultaneously exploring the model and parameter space, using a reversible jump MCMC sampler. Standard samplers often have low model acceptance probabilities when there are many more regressors than observations. Implementing recent suggestions in the literature leads to much higher acceptance rates. However, high acceptance rates are often associated with poor mixing of chains. Thus, we design a more general model proposal that allows us to propose models "further" from our current model. This proposal can be tuned to achieve a suitable acceptance rate for good mixing. The effectiveness of this proposal is linked to the form of the marginalization scheme when updating the model and we propose a new efficient implementation of the automatic generic transdimensional algorithm of Green (2003). We also implement other previously proposed samplers and compare the efficiency of all methods on some gene expression datasets. Finally, the results of these applications lead us to propose guidelines for choosing between samplers. Relevant code and datasets are posted as an online supplement. [ABSTRACT FROM AUTHOR]

In this work we propose Bayesian measures to quantify the influence of observations on the structural parameters of the simple measurement error model (MEM). Different influence measures, like those based on q-divergence between posterior distributions and Bayes risk, are studied to evaluate the influence. A strategy based on the perturbation function and MCMC samples is used to compute these measures. The samples from the posterior distributions are obtained by using the Metropolis-Hastings algorithm and assuming specific proper prior distributions. The results are illustrated with an application to a real example modeled with MEM in the literature. [ABSTRACT FROM AUTHOR]

The question of how the well-known Neyman stratified allocation result generalizes when it is formally assumed that there is prior information concerning the unknown stratum means is dealt with here. This prior information is taken to be expressible in the form of a multivariate normal prior distribution. Several methods of assessing prior distributions are discussed. The allocation for stratified sampling is shown to be a special case of a more general allocation problem. A computational algorithm is presented for this more general problem of finding the allocation of sampling effort which minimizes the posterior variance of any given linear combination of unknown normal process means subject to a budget constraint. A feature of the solution is that for limited budgets one may rely solely on his prior information concerning some strata, sampling only in a subset of the strata. Finally, several applications are briefly described including a "non-Bayesian" solution to a particular problem of allocation for a multipurpose stratified sample. [ABSTRACT FROM AUTHOR]