You-Gan Wang

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So far, most Phase II trials have been designed and analysed under a frequentist framework. Under this framework, a trial is designed so that the overall Type I and Type II errors of the trial are controlled at some desired levels. Recently, a number of articles have advocated the use of Bayesian designs in practice. Under a Bayesian framework, a trial is(More)
In analysis of longitudinal data, the variance matrix of the parameter estimates is usually estimated by the 'sandwich' method, in which the variance for each subject is estimated by its residual products. We propose smooth bootstrap methods by perturbing the estimating functions to obtain 'bootstrapped' realizations of the parameter estimates for(More)
Comparisons of growth rates of populations and species are important in fi sheries science for a range of reasons that vary with the context of each study. Most studies of fi sh growth have focused on the practical issues of the most appropriate way of comparing growth rather than on recognizing that there are several methods for making these comparisons(More)
Background: I • Queensland Bulk Water Supply Authority (Seqwater) manages catchments, water storages and treatment services to ensure quality and quantity of water supplied to Southeast Queensland • ongoing monitoring program recently upgraded with permanent installation of vertical profilers at Lake Wivenhoe dam • each profiler monitors water quality(More)
The method of generalized estimating equations (GEEs) provides consistent estimates of the regression parameters in a marginal regression model for longitudinal data, even when the working correlation model is misspecified (Liang and Zeger, 1986). However, the efficiency of a GEE estimate can be seriously affected by the choice of the working correlation(More)
The approach of generalized estimating equations (GEE) is based on the framework of generalized linear models but allows for specification of a working matrix for modeling within-subject correlations. The variance is often assumed to be a known function of the mean. This article investigates the impacts of misspecifying the variance function on estimators(More)