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作者：Shen, Xiaotong; Huang, Hsin-Cheng; Pan, Wei
作者单位：University of Minnesota System; University of Minnesota Twin Cities; Academia Sinica - Taiwan; University of Minnesota System; University of Minnesota Twin Cities
摘要：In this article, we propose a regression method for simultaneous supervised clustering and feature selection over a given undirected graph, where homogeneous groups or clusters are estimated as well as informative predictors, with each predictor corresponding to one node in the graph and a connecting path indicating a priori possible grouping among the corresponding predictors. The method seeks a parsimonious model with high predictive power through identifying and collapsing homogeneous group...
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作者：Wei, Ying; Ma, Yanyuan; Carroll, Raymond J.
作者单位：Columbia University; Texas A&M University System; Texas A&M University College Station
摘要：We propose a multiple imputation estimator for parameter estimation in a quantile regression model when some covariates are missing at random. The estimation procedure fully utilizes the entire dataset to achieve increased efficiency, and the resulting coefficient estimators are root-n consistent and asymptotically normal. To protect against possible model misspecification, we further propose a shrinkage estimator, which automatically adjusts for possible bias. The finite sample performance of...
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作者：Garthwaite, Paul H.; Critchley, Frank; Anaya-Izquierdo, Karim; Mubwandarikwa, Emmanuel
作者单位：Open University - UK
摘要：Two transformations are proposed that give orthogonal components with a one-to-one correspondence between the original vectors and the components. The aim is that each component should be close to the vector with which it is paired, orthogonality imposing a constraint. The transformations lead to a variety of new statistical methods, including a unified approach to the identification and diagnosis of collinearities, a method of setting prior weights for Bayesian model averaging, and a means of...
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作者：Huang, Hanwen; Liu, Yufeng; Marron, J. S.
作者单位：University of Texas System; University of Texas Health Science Center Houston; University of North Carolina; University of North Carolina Chapel Hill
摘要：Linear classifiers are very popular, but can have limitations when classes have distinct subpopulations. General nonlinear kernel classifiers are very flexible, but do not give clear interpretations and may not be efficient in high dimensions. We propose the bidirectional discrimination classification method, which generalizes linear classifiers to two or more hyperplanes. This new family of classification methods gives much of the flexibility of a general nonlinear classifier while maintainin...
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作者：Griffin, J. E.; Brown, P. J.
作者单位：University of Kent
摘要：This paper develops a rich class of sparsity priors for regression effects that encourage shrinkage of both regression effects and contrasts between effects to zero whilst leaving sizeable real effects largely unshrunk. The construction of these priors uses some properties of normal-gamma distributions to include design features in the prior specification, but has general relevance to any continuous sparsity prior. Specific prior distributions are developed for serial dependence between regres...
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作者：Azriel, D.; Mandel, M.; Rinott, Y.
作者单位：Hebrew University of Jerusalem
摘要：We study allocations that maximize the power of tests of equality of two treatments having binary outcomes. When a normal approximation applies, the asymptotic power is maximized by minimizing the variance, leading to a Neyman allocation that assigns observations in proportion to the standard deviations. This allocation, which in general requires knowledge of the parameters of the problem, is recommended in a large body of literature. Under contiguous alternatives the normal approximation inde...
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作者：Hall, Peter; Maiti, Tapabrata
作者单位：University of Melbourne; Michigan State University
摘要：In some problems involving functional data, it is desired to undertake prediction or classification before the full trajectory of a function is observed. In such cases, it is often preferable to suffer somewhat greater error in return for making a decision relatively early. The prediction and classification problems can be treated similarly, using mean squared prediction error, or classification error, respectively, as the means for quantifying performance, so in this paper we focus principall...
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作者：Chan, Kwun Chuen Gary; Chen, Ying Qing; Di, Chong-Zhi
作者单位：University of Washington; University of Washington Seattle; Fred Hutchinson Cancer Center
摘要：To study disease association with risk factors in epidemiologic studies, cross-sectional sampling is often more focused and less costly for recruiting study subjects who have already experienced initiating events. For time-to-event outcome, however, such a sampling strategy may be length biased. Coupled with censoring, analysis of length-biased data can be quite challenging, due to induced informative censoring in which the survival time and censoring time are correlated through a common backw...
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作者：Huang, Alan; Rathouz, Paul J.
作者单位：University of Chicago; University of Wisconsin System; University of Wisconsin Madison
摘要：The proportional likelihood ratio model introduced in Luo & Tsai (2012) is adapted to explicitly model the means of observations. This is useful for the estimation of and inference on treatment effects, particularly in designed experiments and allows the data analyst greater control over model specification and parameter interpretation.
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作者：Papaspiliopoulos, Omiros; Pokern, Yvo; Roberts, Gareth O.; Stuart, Andrew M.
作者单位：Pompeu Fabra University; University of London; University College London; University of Warwick; University of Warwick
摘要：We consider estimation of scalar functions that determine the dynamics of diffusion processes. It has been recently shown that nonparametric maximum likelihood estimation is ill-posed in this context. We adopt a probabilistic approach to regularize the problem by the adoption of a prior distribution for the unknown functional. A Gaussian prior measure is chosen in the function space by specifying its precision operator as an appropriate differential operator. We establish that a Bayesian-Gauss...
