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作者：Yu, Tao; Li, Pengfei
作者单位：National University of Singapore; University of Waterloo
摘要：Diffusion tensor imaging (DTI), based on the diffusion-weighted imaging (DWI) data acquired from magnetic resonance experiments, has been widely used to analyze the physical structure of white-matter fibers in the human brain in vivo. The raw DWI data, however, carry noise; this contaminates the diffusion tensor (DT) estimates and introduces systematic bias into the induced eigenvalues. These bias components affect the effectiveness of fiber-tracking algorithms. In this article, we propose a t...
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作者：Ghosh, Arpita; Wright, Fred A.; Zou, Fei
作者单位：Public Health Foundation of India; University of North Carolina; University of North Carolina Chapel Hill
摘要：It has been repeatedly shown that in case control association studies, analysis of a secondary trait that ignores the original sampling scheme can produce highly biased risk estimates. Although a number of approaches have been proposed to properly analyze secondary traits, most approaches fail to reproduce the marginal logistic model assumed for the original case control trait and/or do not allow for interaction between secondary trait and genotype marker on primary disease risk. In addition, ...
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作者：Hanks, Ephraim M.; Hooten, Mevin B.
作者单位：Colorado State University System; Colorado State University Fort Collins; United States Department of the Interior; United States Geological Survey; Colorado State University System; Colorado State University Fort Collins
摘要：Circuit theory has seen extensive recent use in the field of ecology, where it is often applied to study functional connectivity. The landscape is typically represented by a network of nodes and resistors, with the resistance between nodes a function of landscape characteristics. The effective distance between two locations on a landscape is represented by the resistance distance between the nodes in the network. Circuit theory has been applied to many other scientific fields for exploratory a...
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作者：Weinstein, Asaf; Fithian, William; Benjamini, Yoav
作者单位：University of Pennsylvania; Stanford University; Tel Aviv University; Tel Aviv University
摘要：In many current large-scale problems, confidence intervals (CIs) are constructed only for the parameters that are large, as indicated by their estimators, ignoring the smaller parameters. Such selective inference poses a problem to the usual marginal CIs that no longer offer the right level of coverage, not even on the average over the selected parameters. We address this problem by developing three methods to construct short and valid CIs for the location parameter of a symmetric unimodal dis...
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作者：Raymer, James; Wisniowski, Arkadiusz; Forster, Jonathan J.; Smith, Peter W. F.; Bijak, Jakub
作者单位：University of Southampton
摘要：International migration data in Europe are collected by individual countries with separate collection systems and designs. As a result, reported data are inconsistent in availability, definition, and quality. In this article, we propose a Bayesian model to overcome the limitations of the various data sources. The focus is on estimating recent international migration flows among 31 countries in the European Union and European Free Trade Association from 2002 to 2008, using data collated by Euro...
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作者：Liang, Faming; Cheng, Yi Hen; Song, Qifan; Park, Jincheol; Yang, Ping
作者单位：Texas A&M University System; Texas A&M University College Station; Texas A&M University System; Texas A&M University College Station
摘要：The Gaussian geostatistical model has been widely used in modeling of spatial data. However, it is challenging to computationally implement this method because it requires the inversion of a large covariance matrix, particularly when there is a large number of observations. This article proposes a resampling-based stochastic approximation method to address this challenge. At each iteration of the proposed method, a small subsample is drawn from the full dataset, and then the current estimate o...
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作者：Mammen, Enno
作者单位：University of Mannheim
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作者：Cheng, Jerry Q.; Xie, Minge; Chen, Rong; Roberts, Fred
作者单位：Rutgers University System; Rutgers University New Brunswick; Rutgers University Biomedical & Health Sciences; Rutgers University System; Rutgers University New Brunswick; Rutgers University System; Rutgers University New Brunswick; Rutgers University System; Rutgers University New Brunswick
摘要：Potential nuclear attacks are among the most devastating terrorist attacks, with severe loss of human lives as well as damage to infrastructure. To deter such threats, it becomes increasingly vital to have sophisticated nuclear surveillance and detection systems deployed in major cities in the United States, such as New York City. In this article, we design a mobile sensor network and develop statistical algorithms and models to provide consistent and pervasive surveillance of nuclear material...
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作者：Flynn, Cheryl J.; Hurvich, Clifford M.; Simonoff, Jeffrey S.
作者单位：New York University
摘要：It has been shown that Akaike information criterion (AIC)-type criteria are asymptotically efficient selectors of the tuning parameter in nonconcave penalized regression methods under the assumption that the population variance is known or that a consistent estimator is available. We relax this assumption to prove that AIC itself is asymptotically efficient and we study its performance in finite samples. In classical regression, it is known that AIC tends to select overly complex models when t...
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作者：Vanderweele, Tyler J.; Hong, Guanglei; Jones, Stephanie M.; Brown, Joshua L.
作者单位：Harvard University; Harvard T.H. Chan School of Public Health; Harvard University; Harvard T.H. Chan School of Public Health; University of Chicago; Harvard University; Fordham University
摘要：Peer influence and social interactions can give rise to spillover effects in which the exposure of one individual may affect outcomes of other individuals. Even if the intervention under study occurs at the group or cluster level as in group-randomized trials, spillover effects can occur when the mediator of interest is measured at a lower level than the treatment. Evaluators who choose groups rather than individuals as experimental units in a randomized trial often anticipate that the desirab...
