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作者：Cole, BF; Lee, MLT; Whitmore, GA; Zaslavsky, AM
作者单位：Brown University; Harvard University; Harvard University Medical Affiliates; Brigham & Women's Hospital; Harvard University; Harvard Medical School; McGill University; Harvard University
摘要：We develop an improved empirical Bayes estimation methodology for the analysis of two-state Markov chains observed from heterogeneous individuals. First, the two transition probabilities corresponding to each chain are assumed to be drawn from a common, bivariate distribution that has beta marginals. Second, randomly missing observations are incorporated into the likelihood for the hyperparameters by efficiently summing over all possible values for the missing observations. A likelihood ratio ...
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作者：Gasser, T; Kneip, A
摘要：The shape of a regression curve can to a large extent be characterized by the succession of structural features like extrema, inflection points, and so on. When analyzing a sample of regression curves, it is often important to know al an early stage of data analysis which structural features are occurring consistently in each curve of the sample. Such a definition is usually nor easy due to substantial interindividual variation both in the x and the y axis and due to the influence of noise. A ...
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作者：Olkin, I; Viana, M
作者单位：University of Illinois System; University of Illinois Chicago; University of Illinois Chicago Hospital; University of Illinois System; University of Illinois Chicago; University of Illinois Chicago Hospital
摘要：In measuring visual acuity, the extremes of a set of normally distributed measures are of concern, together with one or more covariates. This leads to a model in which (X, Y-1, Y-2) are jointly normally distributed with Y-1, Y-2 exchangeable and (X, Y-i) having a common correlation. Inferential procedures are developed for correlations and linear regressions among X and the ordered Y values. This requires determination of the covariance matrix of X, Y-(1) = min{Y-1, Y-2} and Y(2) = max(Y-1, Y-...
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作者：Gilula, Z; Haberman, SJ
作者单位：University of Chicago; Northwestern University
摘要：Measures of dispersion for categorical random variables based on penalty functions play a central role in establishing relevant measures of association between such variables. The literature concerning these measures provides little systematic treatment of such aspects of these measures as comparability, efficient estimation, and large-sample properties. This article provides a systematic and rigorous construction of dispersion measures based on penalty functions. Efficient estimation procedur...
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作者：Gurland, J; Sethuraman, J
作者单位：State University System of Florida; Florida State University
摘要：Although mixtures of decreasing failure rate (DFR) distributions are always DFR, some mixtures of increasing failure rate (IFR) distributions can also be ultimately DFR. In this article various types of discrete and continuous mixtures of IFR distributions are considered, and conditions are developed for such mixtures to be ultimately DFR. These conditions lead to an interesting result-that certain mixtures of IFR distributions, even those with very rapidly increasing failure rates (e.g., Weib...
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作者：Lambert, D; Roeder, K
作者单位：Yale University
摘要：Generalized linear models (GLM's) are simple, convenient models for count data, but they assume that the variance is a specified function of the mean. Although overdispersed GLM's allow more flexible mean-variance relationships, they are often not as simple to interpret nor as easy to fit as standard GLM's. This article introduces a convexity plot, or C plot for short, that detects overdispersion and relative variance curves and relative variance tests that help to understand the nature of the...
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作者：Nychka, D; Gray, G; Haaland, P; Martin, D; OConnell, M
作者单位：National Oceanic Atmospheric Admin (NOAA) - USA; Becton Dickinson
摘要：In the biomedical products industry, measures of the quality of individual clinical specimens or manufacturing production units are often available in the form of high-dimensional data such as continuous recordings obtained from an analytical instrument. These recordings are then examined by experts in the field who extract certain features and use these to classify individuals. To formalize and quantify this procedure, an approach for extracting features from recordings based on nonparametric...
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作者：Ruppert, D; Sheather, SJ; Wand, MP
作者单位：University of New South Wales Sydney
摘要：Local least squares kernel regression provides an appealing solution to the nonparametric regression, or ''scatterplot smoothing'', problem, as demonstrated by Fan, for example. The practical implementation of any scatterplot smoother is greatly enhanced by the availability of a reliable rule for automatic selection of the smoothing parameter. In this article we apply the ideas of plug-in bandwidth selection to develop strategies for choosing the smoothing parameter of local linear squares ker...
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作者：Chib, S
摘要：In the context of Bayes estimation via Gibbs sampling, with or without data augmentation, a simple approach is developed for computing the marginal density of the sample data (marginal likelihood) given parameter draws from the posterior distribution. Consequently, Bayes factors for model comparisons can be routinely computed as a by-product of the simulation. Hitherto, this calculation has proved extremely challenging. Our approach exploits the fact that the marginal density can be expressed ...
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作者：Marden, JI; Muyot, MET
摘要：A class of rank tests for analysis of variance based on linear functions of the Wilcoxon/Mann-Whitney statistics between cells is studied. This class includes many popular procedures. Assuming a location-family model, a condition for optimal Pitman efficacy of tests of main effects in this class is given. Tests for main effects in two-way layouts that achieve this optimality are shown to improve on previous proposals when the sample sizes are unbalanced. Nested orthogonal contrasts are introdu...
