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作者：Morgan, John P.; Wang, Xiaowei
作者单位：Virginia Polytechnic Institute & State University; GlaxoSmithKline; Glaxosmithkline USA
摘要：An optimality framework is developed for designing experiments in which not all treatments are of equal interest, such as those including an established control. Differential interest in treatments is formalized by assignment of weights. incorporated into optimality measures through a weighted version of the information matrix. All conventional measures of design efficacy are shown to have weighted analogs. The properties of weighted measures are explored, some general theory is developed, and...
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作者：Baiocchi, Mike; Small, Dylan S.; Lorch, Scott; Rosenbaum, Paul R.
作者单位：University of Pennsylvania; University of Pennsylvania; University of Pennsylvania; Pennsylvania Medicine; Childrens Hospital of Philadelphia
摘要：An instrument is a random nudge toward acceptance of a treatment that affects outcomes only to the extent that it affects acceptance of the treatment. Nonetheless, in settings in which treatment assignment is mostly deliberate and not random, there may exist some essentially random nudges to accept treatment, so that use of an instrument might extract bits of random treatment assignment from a setting that is otherwise quite biased in its treatment assignments. An instrument is weak if the ran...
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作者：Wang, C.; Daniels, M. J.; Scharfstein, D. O.; Land, S.
作者单位：State University System of Florida; University of Florida; US Food & Drug Administration (FDA); Johns Hopkins University; Johns Hopkins Bloomberg School of Public Health; Pennsylvania Commonwealth System of Higher Education (PCSHE); University of Pittsburgh
摘要：We consider inference in randomized longitudinal studies with missing data that is generated by skipped clinic visits and loss to followup. In this setting, it is well known that full data estimands are not identified unless unverified assumptions are imposed. We assume a non-future dependence model for the drop-out mechanism and partial ignorability for the intermittent missingness. We posit an exponential tilt model that links nonidentifiable distributions and distributions identified under ...
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作者：Chen, Rong; Guo, Re-Jin; Lin, Ming
作者单位：Rutgers University System; Rutgers University New Brunswick; Peking University; University of Illinois System; University of Illinois Chicago; University of Illinois Chicago Hospital; Xiamen University
摘要：Examination on firm performance subsequent to a chosen event is widely used in finance studies to analyze the motivation behind managerial decisions. However, results are often subject to bias when the self-selectivity behind managerial decisions is ignored and unspecified. This study investigates a unique corporate event of initial public offering (IPO) withdrawal, where a firm's subsequent likelihood of bankruptcy is specified in a system of switching hazard models, and the expected differen...
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作者：Gao, Xin; Song, Peter X. -K.
作者单位：York University - Canada; University of Michigan System; University of Michigan
摘要：For high-dimensional data sets with complicated dependency structures, the full likelihood approach often leads to intractable computational complexity. This imposes difficulty on model selection, given that most traditionally used information criteria require evaluation of the full likelihood. We propose a composite likelihood version of the Bayes information criterion (BIC) and establish its consistency property for the selection of the true underlying marginal model. Our proposed BIC is sho...
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作者：Zhu, Li-Ping; Zhu, Li-Xing; Feng, Zheng-Hui
作者单位：Shanghai University of Finance & Economics; Hong Kong Baptist University
摘要：In this paper we offer a complete methodology of cumulative slicing estimation to sufficient dimension reduction. In parallel to the classical slicing estimation, we develop three methods that are termed, respectively, as cumulative mean estimation, cumulative variance estimation, and cumulative directional regression. The strong consistency for p = O(n(1/2)/log n) and the asymptotic normality for p = o(n(1/2)) are established, where p is the dimension of the predictors and n is sample size. S...
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作者：Baladandayuthapani, Veerabhadran; Ji, Yuan; Talluri, Rajesh; Nieto-Barajas, Luis E.; Morris, Jeffrey S.
作者单位：University of Texas System; UTMD Anderson Cancer Center; University of Texas System; UTMD Anderson Cancer Center; Texas A&M University System; Texas A&M University College Station; Instituto Tecnologico Autonomo de Mexico
摘要：Array-based comparative genomic hybridization (aCGH) is a high-resolution, high-throughput technique for studying the genetic basis of cancer. The resulting data consist of log fluorescence ratios as a function of the genomic DNA location and provide a cytogenetic representation of the relative DNA copy number variation. Analysis of such data typically involves estimating the underlying copy number state at each location and segmenting regions of DNA with similar copy number states. Most curre...
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作者：Li, Fan; Zaslavsky, Alan M.
作者单位：Duke University; Harvard University; Harvard Medical School
摘要：We use data collected in the National Comorbidity Survey-Adolescent (NCS-A) to develop a methodology to estimate the small-area prevalence of serious emotional distress (SED) in schools in the United States, exploiting the clustering of the main NCS-A sample by school. The NCS-A instrument includes both a short screening scale, the K6, and extensive diagnostic assessments of the individual disorders and associated impairment that determine the diagnosis of SED. We fitted a Bayesian bivariate m...
