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作者：Conti, Pier Luigi; Marella, Daniela; Scanu, Mauro
作者单位：Sapienza University Rome; Roma Tre University
摘要：The goal of statistical matching is the estimation of a joint distribution having observed only samples from its marginals. The lack of joint observations on the variables of interest is the reason of uncertainty about the joint population distribution function. In the present article, the notion of matching error is introduced, and upper-bounded via an appropriate measure of uncertainty. Then, an estimate of the distribution function for the variables not jointly observed is constructed on th...
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作者：Li, Degui; Qian, Junhui; Su, Liangjun
作者单位：University of York - UK; Shanghai Jiao Tong University; Singapore Management University
摘要：In this article, we consider estimation of common structural breaks in panel data models with unobservable interactive fixed effects. We introduce a penalized principal component (PPC) estimation procedure with an adaptive group fused LASSO to detect the multiple structural breaks in the models. Under some mild conditions, we show that with probability approaching one the proposed method can correctly determine the unknown number of breaks and consistently estimate the common break dates. Furt...
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作者：Patilea, Valentin; Sanchez-Sellero, Cesar; Saumard, Matthieu
作者单位：Ecole Nationale de la Statistique et de l'Analyse de l'Information (ENSAI); Bucharest University of Economic Studies; Universidade de Santiago de Compostela; Pontificia Universidad Catolica de Valparaiso
摘要：This article examines the problem of nonparametric testing,for the no-effect of a random covariate (or predictor) on a functional response. This means testing whether the conditional expectation of the response given the covariate is almost surely zero or not, without imposing any model relating response and covariate. The covariate could be univariate, multivariate, or functional. Our test statistic is a quadratic form involving univariate nearest neighbor smoothing and the asymptotic critica...
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作者：Bura, Efstathia; Duarte, Sabrina; Forzani, Liliana
作者单位：George Washington University; National University of the Littoral
摘要：We develop methodology for identifying and estimating sufficient reductions in regressions with predictors that, given the response, follow a multivariate exponential family distribution. This setup includes regressions where predictors are all continuous, all categorical, or mixtures of categorical and continuous. We derive the minimal sufficient reduction of the predictors and its maximum likelihood estimator by modeling the conditional distribution of the predictors given the response. Wher...
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作者：Chen, Jingxiang; Liu, Yufeng; Zeng, Donglin; Song, Rui; Zhao, Yingqi; Kosorok, Michael R.
作者单位：University of North Carolina; University of North Carolina Chapel Hill; University of North Carolina School of Medicine; University of North Carolina; University of North Carolina Chapel Hill; University of North Carolina School of Medicine; North Carolina State University; Fred Hutchinson Cancer Center; University of North Carolina; University of North Carolina Chapel Hill; University of North Carolina School of Medicine
摘要：Xu, Muller, Wahed, and Thall proposed a Bayesian model to analyze an acute leukemia study involving multi :stage chemotherapy regimes. We discuss two alternative methods, Q-learning and O-learning, to solve the same problem from the machine learning point of view. The numerical studies show that these methods can be flexible and have advantages in some situations to handle treatment heterogeneity while being robust to model misspecification.
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作者：Yue, Chen; Zipunnikov, Vadim; Bazin, Pierre-Louis; Dzung Pham; Reich, Daniel; Crainiceanu, Ciprian; Caffo, Brian
作者单位：Johns Hopkins University; Max Planck Society; United States Department of Defense; Center for Neuroscience & Regenerative Medicine (CNRM); National Institutes of Health (NIH) - USA; National Institutes of Health (NIH) - USA; NIH National Institute of Neurological Disorders & Stroke (NINDS)
摘要：In this article, we are concerned with data generated from a diffusion tensor imaging (DTI). experiment. The goal is to parameterize manifold-like white matter tracts, such as the corpus callosum, using principal surfaces. The problem is approached by finding a geometrically motivated surface-based representation of the corpus callosum and visualized fractional anisotropy (FA) values projected onto the surface. The method also applies to any other diffusion summary. An algorithm is proposed th...
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作者：Fisher, Aaron; Caffo, Brian; Schwartz, Brian; Zipunnikov, Vadim
作者单位：Johns Hopkins University; Johns Hopkins Bloomberg School of Public Health
摘要：Many have suggested a bootstrap procedure for estimating the sampling variability of principal component analysis (PCA) results. However, when the number of measurements per subject (p) is much larger than the number of subjects (n), calculating and storing the leading principal components (PCs) from each bootstrap sample can be computationally infeasible. To address this, we outline methods for fast, exact calculation of bootstrap PCs, eigenvalues, and scores. Our methods leverage the fact th...
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作者：Han, Peisong; Lawless, Jerald F.
作者单位：University of Waterloo
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作者：Chang, W.; Haran, M.; Applegate, P.; Pollard, D.
作者单位：University System of Ohio; University of Cincinnati
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作者：Duivesteijn, Wouter
作者单位：Ghent University; Interuniversity Microelectronics Centre; Ghent University
摘要：Zhang derives approximations for the distribution of a mixture of chi-squared distributions. The two derived approximation bounds in Theorem 1.1 both contain an arithmetic error. These are corrected here.
