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作者：Simon, Noah; Tibshirani, Robert
作者单位：University of Washington; University of Washington Seattle; Stanford University; Stanford University
摘要：To date testing interactions in high dimensions is a challenging task. Existing methods often have issues with sensitivity to modeling assumptions and heavily asymptotic nominal p-values. To help alleviate these issues, we propose a permutation-based method for testing marginal interactions with a binary response. Our method searches for pairwise correlations that differ between classes. In this article, we compare our method on real and simulated data to the standard approach of running many ...
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作者：Zhang, Yichi; Laber, Eric B.
作者单位：North Carolina State University
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作者：Cook, R. Dennis; Zhang, Xin
作者单位：University of Minnesota System; University of Minnesota Twin Cities; State University System of Florida; Florida State University
摘要：Envelopes were recently proposed by Cook, Li and Chiaromonte as a method for reducing estimative and predictive variations in multivariate linear regression. We extend their formulation, proposing a general definition of an envelope and a general framework for adapting envelope methods to any estimation procedure. We apply the new envelope methods to weighted least squares, generalized linear models and Cox regression. Simulations and illustrative data analysis show the potential for envelope ...
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作者：Xu, Yanxun; Mueller, Peter; Yuan, Yuan; Gulukota, Kamalakar; Ji, Yuan
作者单位：University of Texas System; University of Texas Austin; University of Texas System; University of Texas Austin; Baylor College of Medicine; NorthShore University Health System; University of Chicago
摘要：We propose small-variance asymptotic approximations for inference on tumor heterogeneity (TH) using next-generation sequencing data. Understanding TH is an important and open research problem in biology. The lack of appropriate statistical inference is a critical gap in existing methods that the proposed approach aims to fill. We build on a hierarchical model with an exponential family likelihood and a feature allocation prior. The proposed implementation of posterior inference generalizes sim...
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作者：Hallin, Marc; Mehta, Chintan
作者单位：Universite Libre de Bruxelles; Princeton University
摘要：Independent component analysis (ICA) recently has attracted much attention in the statistical literature as an appealing alternative to elliptical models. Whereas k-dimensional elliptical densities depend on one single unspecified radial density, however, k-dimensional independent component distributions involve k unspecified component densities. In practice, for given sample size n and dimension k, this makes the statistical analysis much harder. We focus here on the estimation, from an indep...
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作者：Li, Sai; Mitra, Ritwik; Zhang, Cun-Hui
作者单位：Rutgers University System; Rutgers University New Brunswick; Princeton University
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作者：Azriel, David; Schwartzman, Armin
作者单位：Technion Israel Institute of Technology; University of Pennsylvania; North Carolina State University
摘要：Motivated by the advent of high-dimensional, highly correlated data, this work studies the limit behavior of the empirical cumulative distribution function (ecdf) of standard normal random variables under arbitrary correlation. First, we provide a necessary and sufficient condition for convergence of the ecdf to the standard normal distribution. Next, under general correlation, we show that the ecdf limit is a random, possible infinite, mixture of normal distribution functions that depends on ...
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作者：Finucane, Mariel M.; Paciorek, Christopher J.; Stevens, Gretchen A.; Ezzati, Majid
作者单位：Mathematica; University of California System; University of California Berkeley; World Health Organization; Imperial College London
摘要：Undernutrition, resulting in restricted growth, and quantified here using height-for-age z-scores, is an important contributor to childhood morbidity and mortality. Since all levels of mild, moderate, and severe undemutrition are of clinical and public health importance, it is of interest to estimate the shape of the z-scores' distributions. We present a finite normal mixture model that uses data on 4.3 million children to make annual country-specific estimates of these distributions for under...
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作者：Hodges, Jim
作者单位：University of Minnesota System; University of Minnesota Twin Cities
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作者：Hwang, Beom Seuk; Chen, Zhen
作者单位：National Institutes of Health (NIH) - USA; NIH Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
摘要：In estimating ROC curves of multiple tests, some a priori constraints may exist, either between the healthy and diseased populations within a test or between tests within a population. In this article, we proposed an integrated modeling approach for ROC curves that jointly accounts for stochastic and variability orders. The stochastic order constrains the distributional centers of the diseased and healthy populations within a test, while the variability order constrains the distributional spre...
