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作者：Allard, D; Fraley, C
作者单位：University of Washington; University of Washington Seattle
摘要：This article addresses the problem of estimating the support domain of a bounded point process in presence of background noise. This situation occurs, for example, in the detection of a minefield from aerial observations. A maximum likelihood estimator for a mixture of uniform point processes is derived using a natural partition of the space defined by the data themselves: the Voronoi tessellation. The methodology is tested on simulations and compared to a model-based clustering technique.
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作者：Efron, B; Tibshirani, R
作者单位：University of Toronto
摘要：A training set of data has been used to construct a rule for predicting future responses. What is the error rate of this rule? This is an important question both for comparing models and for assessing a final selected model. The traditional answer to this question is given by cross-validation. The cross-validation estimate of prediction error is nearly unbiased but can be highly variable. Here we discuss bootstrap estimates of prediction error, which can be thought of as smoothed versions of c...
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作者：Akritas, MG; Brunner, E
作者单位：University of Gottingen
摘要：Nonparametric hypotheses of no main effects, no simple effects, and no interaction effects are considered in the context of factorial designs with censored observations. To test these hypotheses, the asymptotic distribution of quadratic forms of rank statistics is derived using the methodology of martingales for counting processes. The weights used reduce to the usual logistic scores with uncensored data but are different from the weights commonly used for testing the equality of k samples. Th...
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作者：Roeder, K; Wasserman, L
摘要：Mixtures of normals provide a flexible model for estimating densities in a Bayesian framework. There are some difficulties with this model, however. First, standard reference priors yield improper posteriors. Second, the posterior for the number of components in the mixture is not well defined (if the reference prior is used). Third, posterior simulation does not provide a direct estimate of the posterior for the number of components. We present some practical methods for coping with these pro...
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作者：Hedayat, AS; Yan, B; Pezzuto, JM
作者单位：University of Illinois System; University of Illinois Chicago; University of Illinois Chicago Hospital
摘要：For raw optical density (ROD) data, such as those generated in biological assays using a 96-well plate reader, D-optimal designs are identified for a family of homogeneous nonlinear models with two parameters developed for fitting and studying dose-response curves. Further, within the class of k-point equally spaced and uniform designs, D-optimal designs are specified. Also, the D-efficiency of the D-optimal equally spaced and uniform k-point designs are compared to D-optimal design for 3 less...
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作者：Carroll, RJ; Fan, JQ; Gijbels, I; Wand, MP
作者单位：University of North Carolina; University of North Carolina Chapel Hill; Universite Catholique Louvain; University of New South Wales Sydney
摘要：The typical generalized linear model for a regression of a response Y on predictors (X, Z) has conditional mean function based on a linear combination of (X, Z). We generalize these models to have a nonparametric component, replacing the linear combination alpha(0)(T)X + beta(0)(T)Z by eta(0)(alpha(0)(T)X) + beta(0)(T)Z, where eta(0)(.) is an unknown function: We call these generalized partially lineal single-index models (GPLSIM). The models include the ''single-index'' models, which have bet...
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作者：Hsiao, C; Tahmiscioglu, AK
作者单位：University of Wisconsin System; University of Wisconsin Milwaukee
摘要：The issue of financial constraints on company investment is revisited using the U.S. panel data of 561 firms from 1971-1992. A number of economically meaningful factors are discovered to partition firms into relatively homogeneous groups. A mixed fixed- and random-coefficients framework is then used to capture unobserved heterogeneity within groups. The prediction criterion is used to select the final specification and evaluate the importance of financial constraints on firm's investment decis...
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作者：Wu, TJ
作者单位：National Dong Hwa University
摘要：Based on a random sample of size n from an unknown density f on the real line, the problem of adaptively selecting the bandwidth in kernel estimation of f((k)) is investigated, where f((k)) denotes the kth derivative of f. The estimates of density derivatives can be used to evaluate modes and infection points of f and can be applied to the estimation of scores in certain additive models and to the empirical verification of the law of demand in econometrics. For all k, the information bounds fo...
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作者：Sinha, D; Dey, DK
作者单位：University of Connecticut
摘要：This review article investigates the potential of Eayes methods for the analysis of survival data using semiparametric models based on either the hazard or the intensity function. The nonparametric part of every model is assumed to be a realization of a stochastic process. The parametric part, which may include a regression parameter or a parameter quantifying the heterogeneity of a population, is assumed to have a prior distribution with possibly unknown hyperparameters. Careful applications ...
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作者：Hall, P; Huber, C; Speckman, PL
作者单位：Universite Paris Cite; University of Missouri System; University of Missouri Columbia
摘要：When testing hypotheses about the effects of different treatments, variation among covariates can become confounded with that between treatments unless the treatments are applied using paired covariates. In the context of unpaired covariates, we propose implicit covariate-matching methods for testing the hypothesis that one treatment effect is greater than another. The methods are founded on the assumption that the mean treatment effect, conditional on the covariate, is a smooth function of th...
