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作者：Malmberg, Anders; Arellano, Avelino; Edwards, David P.; Flyer, Natasha; Nychka, Doug; Wikle, Christopher
作者单位：Ferring Pharmaceuticals; National Center Atmospheric Research (NCAR) - USA; National Center Atmospheric Research (NCAR) - USA
摘要：Atmospheric Carbon Monoxide (CO) provides a window on the chemistry of the atmosphere since it is one of few chemical constituents that can be remotely sensed, and it can be used to determine budgets of other greenhouse gases Such as ozone and OH radicals. Remote sensing platforms in geostationary Earth orbit will soon provide regional observations of CO at several vertical layers with high spatial and temporal resolution. However, cloudy locations cannot be observed and estimates of the compl...
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作者：Frieman, Jerome H.; Popescu, Bogdan E.
作者单位：Stanford University
摘要：General regression and classification models are constructed as linear combinations of simple rules derived from the data. Each rule consists of a conjunction of a small number of simple statements concerning the values of individual input variables. These rule ensembles are shown to produce predictive accuracy comparable to the best methods. However, their principle advantage lies in interpretation. Because of its simple form, each rule is easy to understand, as it its influence on individual...
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作者：Proietti, Tommaso; Luati, Alessandra
作者单位：University of Rome Tor Vergata; University of Bologna
摘要：The paper focuses on the adaptation of local polynomial filters at the end of the sample period. We show that for real time estimation of signals (i.e., exactly at the boundary of the time support) we cannot rely on the automatic adaptation of the local polynomial smoothers, since the direct real time filter turns out to be strongly localized, and thereby yields extremely volatile estimates. As an alternative, we evaluate a general family of asymmetric filters that minimizes the mean square re...
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作者：Venturini, Sergio; Dominici, Francesca; Parmigiani, Giovanni
作者单位：Bocconi University; Johns Hopkins University; Johns Hopkins Bloomberg School of Public Health; Johns Hopkins University; Johns Hopkins Medicine
摘要：An important question in health services research is the estimation of the proportion of medical expenditures that exceed a given threshold. Typically, medical expenditures present highly skewed, heavy tailed distributions, for which (a) simple variable transformations are insufficient to achieve a tractable low-dimensional parametric form and (b) nonparametric methods are not efficient in estimating exceedance probabilities for large thresholds. Motivated by this context, in this paper we pro...
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作者：Brown, Lawrence D.
作者单位：University of Pennsylvania
摘要：Batting average is one of the principle performance measures for an individual baseball player. It is natural to statistically model this as a bionomial variable proportion, with a given (observed) number of qualifying attempts (called at-bats), an observed number of successes (hits) distributed according to the binomial distribution, and with a true (but unknown) value of pi that represents the player's latent ability. This is a common data structure in many statistical applications; and so t...
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作者：Diaconis, Persi; Goel, Sharad; Holmes, Susan
作者单位：Stanford University; Yahoo! Inc
摘要：Classical Multidimensional scaling (MDS) is a method for visualizing high-dimensional point clouds by mapping to low-dimensional Euclidean space. This mapping is defined in terms of eigenfunctions of a matrix of inter-point dissimilarities. In this paper we analyze in detail multidimensional scaling applied to a specific dataset: the 2005 United States House of Representatives roll call votes. Certain MDS and kernel projections output horseshoes that are characteristic of dimensionality reduct...
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作者：Ishwaran, Hemant; Kogalur, Udaya B.; Blackstone, Eugene H.; Lauer, Michael S.
作者单位：Cleveland Clinic Foundation; Columbia University; Cleveland Clinic Foundation; National Institutes of Health (NIH) - USA; NIH National Heart Lung & Blood Institute (NHLBI)
摘要：We introduce random survival forests, a random forests method for the analysis of right-censored survival data. New survival splitting rules for growing survival trees are introduced, as is a new missing data algorithm for imputing missing data. A conservation-of-events principle for survival forests is introduced and used to define ensemble mortality, a simple interpretable measure of mortality that can be used as a predicted outcome. Several illustrative examples are given, including a case ...
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作者：Shen, Haipeng; Huang, Jianhua Z.
作者单位：University of North Carolina; University of North Carolina Chapel Hill; Texas A&M University System; Texas A&M University College Station
摘要：We consider forecasting the latent rate profiles of a time series of inhomogeneous Poisson processes. The work is motivated by operations management of queueing systems, in particular, telephone call centers, where accurate forecasting of call arrival rates is a crucial primitive for efficient staffing of such centers. Our forecasting approach utilizes dimension reduction through a factor analysis of Poisson variables, followed by time series modeling of factor score series. Time series foreca...
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作者：Kou, S. C.
作者单位：Harvard University
摘要：Advances in nanotechnology have allowed scientists to study biological process on an unprecedented nanoscale molecule-by-molecule basis, opening the door to addressing many important biological problems. A phenomenon observed in recent nanoscale single-molecule biophysics experiments is subdiffusion, which largely departs from the classical Brownian diffusion theory. In this paper, by incorporating fractional Gaussian noise into the generalized Langevin equation, we formulate a model to descri...
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作者：Schwartzman, Armin; Dougherty, Robert F.; Taylor, Jonathan E.
作者单位：Harvard University; Harvard T.H. Chan School of Public Health; Harvard University Medical Affiliates; Dana-Farber Cancer Institute; Stanford University; Stanford University
摘要：Diffusion tensor imaging (DTI) is a novel modality of magnetic resonance imaging that allows noninvasive mapping, of the brain's white matter. A particular map derived from DTI measurements is a map of water principal diffusion directions, which are proxies for neural fiber directions. We consider a study in which diffusion direction maps were acquired for two groups of subjects. The objective of the analysis is to find regions of the brain in which the corresponding diffusion directions diffe...
