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作者：Lam, KF; Kuk, AYC
作者单位：University of New South Wales Sydney
摘要：A marginal likelihood approach is proposed for estimating the parameters ill a frailty model using clustered survival data. To overcome the analytic intractability of the marginal likelihood function, we propose a Monte Carlo approximation using the technique of importance sampling. Implementation is by means of simulations from the uniform distribution. The suggested method can cope with censoring and unequal cluster sizes and can be applied to any frailty distribution with explicit Laplace t...
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作者：Albert, J; Chib, S
作者单位：Washington University (WUSTL)
摘要：Consider the conditionally independent hierarchical model (CIHM) in which observations yi are independently distributed from f(y(i)/theta(i)), the parameters theta(i) are independently distributed from distributions g(theta/lambda), and the hyperparameters lambda are distributed according to a distribution h(lambda). The posterior distribution of all parameters of the CIHM can be efficiently simulatedby Markov chain Monte Carlo (MCMC) algorithms. Although these simulation algorithms have facil...
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作者：Kallenberg, WCM; Ledwina, T
作者单位：Wroclaw University of Science & Technology
摘要：In recent years several authors have recommended smooth tests for resting goodness of fit. However, the number of components in the smooth test statistic should be chosen well; otherwise, considerable loss of power may occur. Schwarz's selection rule provides one such good choice. Earlier results on simple null hypotheses are extended here to composite hypotheses, which tend to be of mure practical interest. For general composite hypotheses, consistency of the data-driven smooth tests holds at...
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作者：Roeder, K; Wasserman, L
摘要：Mixtures of normals provide a flexible model for estimating densities in a Bayesian framework. There are some difficulties with this model, however. First, standard reference priors yield improper posteriors. Second, the posterior for the number of components in the mixture is not well defined (if the reference prior is used). Third, posterior simulation does not provide a direct estimate of the posterior for the number of components. We present some practical methods for coping with these pro...
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作者：Hedayat, AS; Yan, B; Pezzuto, JM
作者单位：University of Illinois System; University of Illinois Chicago; University of Illinois Chicago Hospital
摘要：For raw optical density (ROD) data, such as those generated in biological assays using a 96-well plate reader, D-optimal designs are identified for a family of homogeneous nonlinear models with two parameters developed for fitting and studying dose-response curves. Further, within the class of k-point equally spaced and uniform designs, D-optimal designs are specified. Also, the D-efficiency of the D-optimal equally spaced and uniform k-point designs are compared to D-optimal design for 3 less...
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作者：Sinha, D; Dey, DK
作者单位：University of Connecticut
摘要：This review article investigates the potential of Eayes methods for the analysis of survival data using semiparametric models based on either the hazard or the intensity function. The nonparametric part of every model is assumed to be a realization of a stochastic process. The parametric part, which may include a regression parameter or a parameter quantifying the heterogeneity of a population, is assumed to have a prior distribution with possibly unknown hyperparameters. Careful applications ...
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作者：Hall, P; Huber, C; Speckman, PL
作者单位：Universite Paris Cite; University of Missouri System; University of Missouri Columbia
摘要：When testing hypotheses about the effects of different treatments, variation among covariates can become confounded with that between treatments unless the treatments are applied using paired covariates. In the context of unpaired covariates, we propose implicit covariate-matching methods for testing the hypothesis that one treatment effect is greater than another. The methods are founded on the assumption that the mean treatment effect, conditional on the covariate, is a smooth function of th...
