The use of a Bayesian Hierarchical Model (BHM) to interpret breath measurements obtained during a C Octanoic Breath Test (COBT) is demonstrated. The statistical analysis was implemented using WinBUGS, a commercially available computer package for Bayesian inference. A hierarchical setting was adopted where poorly defined parameters associated with a delayed Gastric Emptying (GE) were able to "b...

We construct and present a Markov Chain Monte Carlo (MCMC) algorithm for the estimation of posterior odds and probabilities of alternative models used to evaluate competing hypotheses regarding three common discrete distributions involved in the modeling of the outstanding claim counts in actuarial science. The proposed methodology involves advanced statistical techniques of Bayesian modeling w...

Title of Dissertation: THE MULTIDIMENSIONAL GENERALIZED GRADED UNFOLDING MODEL FOR ASSESSING CHANGE IN REPEATED MEASURES Weiwei Cui Doctor of Philosophy, 2008 Directed by: Associate Professor James S. Roberts Department of Psychology A multidimensional extension of the generalized graded unfolding model for repeated measures (GGUM-RM) is introduced and applied to analyze attitude change across ...

In this paper, we propose a Bayesian methodology for examining differences between statistics of a social network at two distinct points in time. The problem has been of interest for some time in the social networks community because it is quite difficult to test whether differences over time in statistics such as overall network connectivities are significant. Several issues make this problem ...

1 Goals and Outline Throughout this book, the topic of order-restricted inference is dealt with almost exclusively from a Bayesian perspective. Some readers may wonder why the other main school for statistical inference – frequentist inference – has received so little attention here. Isn't it true that in the field of psychology, almost all inference is frequentist inference? The first goal of ...

A fully Bayesian approach is proposed to the analysis of accuracy and mutuality in interpersonal perceptions. The Bayesian analysis is based on social relations model (SRM) formulation. Inference is straightforward using Markov chain Monte Carlo (MCMC) methods as implemented in the software package WinBUGS. An Example is provided to highlight the use of Bayesian analysis of interpersonal attrac...

In this paper, we are concerned with predicting the number of faults N and the time to next failure of a piece of software. Information in the form of software metrics data is used to estimate the prior distribution of N via a Poisson regression model. Given failure time data, and a well known model for software failures, we show how to sample the posterior distribution using Gibbs sampling, as...

Background Network meta-analysis (NMA) combines direct and indirect evidence from trials to calculate treatment effect estimates and rank treatments. Modelling approaches for continuous and binary outcomes are relatively well developed, but less work has been done with time-toevent outcomes. Such outcomes have usually been analysed using Cox proportional hazard (PH) models, but in oncology with...

BACKGROUND The (13)C-octanoic acid breath test is a convenient method for assessing gastric emptying (GE). Success depends on obtaining a well-characterized time profile of the excretion of label in breath, which may not be the case if GE is delayed. AIMS To use Bayesian techniques in conjunction with hierarchical modelling as a method to increase the success of the modelling process. METHO...

The periwinkle, Littorina sitkana, is found throughout the intertidal zone, often in isolated subpopulations. The majority of trematode parasites use snails as intermediate hosts, and decreased survivorship is often observed in snails infected with trematodes. Sampling L. sitkana from four sites in Barkley Sound, British Columbia, Canada, we test the effects of parasitic infection on snail surv...