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作者：Henderson, R; Shimakura, S; Gorst, D
作者单位：Lancaster University; Universidade Federal do Parana
摘要：In this article we combine ideas from spatial statistics with lifetime data analysis techniques to investigate possible spatial variation in survival of adult acute myeloid leukemia patients in northwest England. Exploratory analysis suggests both clinically and statistically significant variation in survival rates across the region. A multivariate gamma frailty model incorporating spatial dependence is proposed and applied, with results confirming the dependence of hazard on location.
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作者：Stock, JH; Watson, MW
作者单位：Harvard University; National Bureau of Economic Research; Princeton University; Princeton University
摘要：This article considers forecasting a single time series when there are many predictors (N) and time series observations (T). When the data follow an approximate factor model, the predictors can be summarized by a small number of indexes, which we estimate using principal components; Feasible forecasts are shown to be asymptotically efficient in the sense that the difference between the feasible forecasts and the infeasible forecasts constructed using the actual values of the factors converges ...
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作者：Bartolucci, F; Forcina, A
作者单位：University of Perugia
摘要：In the context of two-way contingency tables, the RC model may be seen as a way of modeling the set of log-odds ratios for adjacent 2 x 2 subtables through row and column scores. This article presents an extended class of RC models that allows simultaneous modeling of the marginal distributions and the association between two categorical variables; these components are parameterized with logits and log-odds ratios that may be of different types (e.g., global or continuation) to suit the nature...
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作者：Reilly, C; Schacker, T; Haase, AT; Wietgrefe, S; Krason, D
作者单位：University of Minnesota System; University of Minnesota Twin Cities; University of Minnesota System; University of Minnesota Twin Cities; University of Minnesota System; University of Minnesota Twin Cities
摘要：Here we investigate the clustering of simian immunodeficiency virus (SIV)-infected cells in a lymphatic tissue sample taken from a rhesus macaque to test a spatial proximity model of the spread of infection. We see that standard methods for analysis of the clustering of point processes are not entirely satisfactory for this application, so we define a novel statistic to understand the clustering in the data. This statistic examines how events spread out from certain points deemed cluster cente...
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作者：Green, PJ; Richardson, S
作者单位：University of Bristol; Imperial College London
摘要：We present new methodology to extend hidden Markov models to the spatial domain, and use this class of models to analyze spatial heterogeneity of count data on a rare phenomenon. This situation occurs commonly in many domains of application, particularly in disease mapping. We assume that the counts follow a Poisson model at the lowest level of the hierarchy, and introduce a finite-mixture model for the Poisson rates at the next level. The novelty lies in the model for allocation to the mixtur...
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作者：McLachlan, GJ; Hamaty, KL
作者单位：University of Queensland
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作者：Hanson, T; Johnson, WO
作者单位：University of New Mexico; University of California System; University of California Davis
摘要：We model the error distribution in the standard linear model as a mixture of absolutely continuous Polya trees constrained to have median 0. By considering a mixture, we smooth out the partitioning effects of a simple Polya tree and the predictive error density has a derivative everywhere except 0. The error distribution is centered around a standard parametric family of distributions and thus may be viewed as a generalization of standard models in which important, data-driven features, such a...
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作者：Mittelhammer, R; Judge, G; van Akkeren, M; Cardell, NS
作者单位：Washington State University; Washington State University; University of California System; University of California Berkeley; University of California System; University of California Berkeley
摘要：In the context of a semiparametric regression model with underlying probability distribution unspecified, an extremum estimator formulation is proposed that makes use of empirical likelihood and information theoretic estimation and inference concepts to mitigate the problem of an ill-conditioned design matrix. A squared error loss measure is used to assess estimator performance in finite samples. In large samples, the estimator can be designed to be consistent and asymptotically normal, so tha...
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作者：Newman, KB; Rice, J
作者单位：University of Idaho; University of California System; University of California Berkeley
摘要：To study the factors associated with the freshwater mortality of outmigrating chinook salmon, releases of tagged juvenile salmon were made at multiple locations in the Sacramento River each spring between the years 1979 and 1995. A midwater trawl located downstream of the release sites caught salmon soon after release and, 1 to 4 years later, samples taken from the catches of marine fisheries recovered other tagged fish. An extended quasi-likelihood model was fit to both the freshwater and the...
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作者：Shen, XT; Huang, HC; Cressie, N
作者单位：University System of Ohio; Ohio State University
摘要：Nonparametric hypothesis testing for a spatial signal can involve a large number of hypotheses. For instance,, two satellite images of the same scene, taken before and after an event, could be used to test a hypothesis that the event has no environmental impact. This is equivalent to testing that the mean difference of after-before is zero at each of the (typically thousands of) pixels that make up the scene. In such a situation, conventional testing procedures that control the overall type I ...
