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作者：Balderama, Earvin; Schoenberg, Frederic Paik; Murray, Erin; Rundel, Philip W.
作者单位：University of California System; University of California Los Angeles; University of California System; University of California Los Angeles
摘要：Earthquake occurrences are often described using a class of branching models called epidemic-type aftershock sequence (ETAS) models. The name derives from the fact that the model allows earthquakes to cause aftershocks, and then those aftershocks may induce subsequent aftershocks, and so on. Despite their value in seismology, such models have not previously been used in studying the incidence of invasive plant and animal species. Here, we apply ETAS models to study the spread of an invasive sp...
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作者：Berger, James O.; Bernardo, Jose M.; Sun, Dongchu
作者单位：Duke University; University of Valencia; East China Normal University; University of Missouri System; University of Missouri Columbia
摘要：This article considers the development of objective prior distributions for discrete parameter spaces. Formal approaches to such development such as the reference prior approach-often result in a constant prior for a discrete parameter, which is questionable for problems that exhibit certain types of structure. To take advantage of structure, this article proposes embedding the original problem in a continuous problem that preserves the structure, and then using standard reference prior theory...
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作者：Luo, Xi; Small, Dylan S.; Li, Chiang-Shan R.; Rosenbaum, Paul R.
作者单位：Brown University; Brown University; University of Pennsylvania; Yale University
摘要：An experimental unit is an opportunity to randomly apply or withhold a treatment. There is interference between units if the application of the treatment to one unit may also affect other units. In cognitive neuroscience, a common form of experiment presents a sequence of stimuli or requests for cognitive activity at random to each experimental subject and measures biological aspects of brain activity that follow these requests. Each subject is then many experimental units, and interference be...
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作者：Burgette, Lane F.; Reiter, Jerome P.
作者单位：RAND Corporation; Duke University
摘要：Investigators often change how variables are measured during the middle of data-collection, for example, in hopes of obtaining greater accuracy or reducing costs. The resulting data comprise sets of observations measured on two (or more) different scales, which complicates interpretation and can create bias in analyses that rely directly on the differentially measured variables. We develop approaches based on multiple imputation for handling mid-study changes in measurement for settings withou...
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作者：Li, Ta-Hsin
作者单位：International Business Machines (IBM); IBM USA
摘要：Two periodogram-like functions, called quantile periodograms, are introduced for spectral analysis of time series. The quantile periodograms are constructed from trigonometric quantile regression and motivated by different interpretations of the ordinary periodogram. Analytical and numerical results demonstrate the capability of the quantile periodograms for detecting hidden periodicity in the quantiles and for providing an additional view of time-series data. A connection between the quantile...
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作者：Brannath, W.; Gutjahr, G.; Bauer, P.
作者单位：University of Bremen; Medical University of Vienna
摘要：Adaptive designs allow the investigator of a confirmatory trial to react to unforeseen developments by changing the design. This broad flexibility comes at the price of a complex statistical model where important components, such as the adaptation rule, remain unspecified. It has thus been doubted whether Type I error control can be guaranteed in general adaptive designs. This criticism is fully justified as long as the probabilistic framework on which an adaptive design is based remains vague...
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作者：Chaffee, Paul; van der Laan, Mark
作者单位：University of California System; University of California Berkeley
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作者：Hahn, Ute
作者单位：Aarhus University
摘要：In this study, a new test is proposed for the hypothesis that two (or more) observed point patterns are realizations of the same spatial point process model. To this end, the point patterns are divided into disjoint quadrats, on each of which an estimate of Ripley's K-function is calculated. The two groups of empirical K-functions are compared by a permutation test using a Studentized test statistic. The proposed test performs convincingly in terms of empirical level and power in a simulation ...
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作者：Sardy, Sylvain
作者单位：University of Geneva
摘要：The proposed smooth blockwise iterative thresholding estimator (SBITE) is a model selection technique defined as a fixed point reached by iterating a likelihood gradient-based thresholding function. The smooth James-Stein thresholding function has two regularization parameters lambda and nu, and a smoothness parameter s. It enjoys smoothness like ridge regression and selects variables like lasso. Focusing on Gaussian regression, we show that SBITE is uniquely defined, and that its Stein unbias...
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作者：Wang, Lu; Rotnitzky, Andrea; Lin, Xihong; Millikan, Randall E.; Thall, Peter F.
作者单位：University of Michigan System; University of Michigan; Universidad Torcuato Di Tella; Harvard University; Harvard T.H. Chan School of Public Health; University of Texas System; UTMD Anderson Cancer Center; University of Texas System; UTMD Anderson Cancer Center; University of Texas Health Science Center Houston
摘要：We present new statistical analyses of data arising from a clinical trial designed to compare two-stage dynamic treatment regimes (DTRs) for advanced prostate cancer. The trial protocol mandated that patients be initially randomized among four chemotherapies, and that those who responded poorly be re-randomized to one of the remaining candidate therapies. The primary aim was to compare the DTRs' overall success rates, with success defined by the occurrence of successful responses in each of tw...
