-
作者：Choudhury, Kingshuk Roy; O'Sullivan, Finbarr; Samanta, Mayukh; Caulliez, Guillemette; Shrira, Victor
作者单位：University College Cork; Aix-Marseille Universite; Keele University
摘要：Refractive imaging of wave fields in an established experimental technique We consider the associated reconstruction problem and investigate some statistically motivated refinements. Including (a) bias correction of local slope estimates. (a) regularization of directional slopes (c) spatially weighted reconstruction using the estimated variability of local slope estimates and (d) more accurate estimates of reference light profiles from tune sequence data These refinements are based on a nonpar...
-
作者：Christensen, Ronald; Sun, Siu Kei
作者单位：University of New Mexico
摘要：Fan and Huang (2001) presented a goodness-of-fit test for linear models based on Fourier transformations of the residuals of the fitted model We present two mole theoretically appealing tests in which the Fourier transforms are incorporated into a tilted model We show that when suitably normalized. the new test statistics have the same as distribution as Fan and Huang's test We propose modifications to the asymptotic normalization constants to improve the small sample sizes of our tests while ...
-
作者：Ishwaran, Hemant; Kogalur, Udaya B.; Gorodeski, Eiran Z.; Minn, Andy J.; Lauer, Michael S.
作者单位：Cleveland Clinic Foundation; Cleveland Clinic Foundation; University of Pennsylvania; National Institutes of Health (NIH) - USA; NIH National Heart Lung & Blood Institute (NHLBI)
摘要：The minimal depth of a maximal subtree IN a dimensionless order statistic measuring the predictiveness of a variable in a survival tree We derive the distribution of the minimal depth and use it lot high-dimensional variable selection using random survival forests In big p and small n problems (where p is the dimension and n Is the sample size). the distribution of the minimal depth reveals a ceiling effect in which a tree simply cannot be grown deep enough to properly identify predictive vari...
-
作者：Leng, Chenlei; Zhang, Weiping; Pan, Jianxin
作者单位：National University of Singapore; Chinese Academy of Sciences; University of Science & Technology of China, CAS; University of Manchester
摘要：Efficient estimation of the regression coefficients in longitudinal data analysis requires a correct specification of the covariance structure Existing approaches usually focus on model no the mean with specification of certain covariance structures, which may lead to inefficient or biased estimators of parameters in the mean it misspecification occurs In this article. we propose a data-driven approach based on semiparametric regression models tot the mean and the covariance simultaneously. mo...
-
作者：Nandram, Balgobin; Choi, Jai Won
作者单位：Worcester Polytechnic Institute; University System of Georgia; Augusta University
摘要：Here we analyze body mass index (BMI) data for addict) and adolescents from the Third National Health and Nutrition Examination Survey (NHANES III) Because of the lack of BMI vallies for a considerable number of the children and adolescents, and the differential probabilities of selection of these individuals, serious nonresponse and selection bias in inference can be present To analyze the NHANES III BMI data, a nonignorable nonresponse model has been proposed to estimate the finite populatio...
-
作者：Padoan, S. A.; Ribatet, M.; Sisson, S. A.
作者单位：Swiss Federal Institutes of Technology Domain; Ecole Polytechnique Federale de Lausanne; Swiss Federal Institutes of Technology Domain; Ecole Polytechnique Federale de Lausanne; University of New South Wales Sydney
摘要：The last decade has seen max-stable processes emerge as a common tool for the statistical modeling of spatial extremes However, their application is complicated due to the unavailability of the multivariate density function and so likehhood-based methods remain far from providing a complete and flexible framework kit inference In this article we develop inferentially practical likehhood-based methods for fitting max-stable processes derived from a composite-likehhood approach The procedure is ...
-
作者：Cerioli, Andrea
作者单位：University of Parma
摘要：In this paper we develop multivariate outlier tests based on the high-breakdown Minimum Covariance Determinant estimator The rules that we propose have good performance under the null hypothesis of no outliers in the data and also appreciable power properties for the purpose of individual outlier detection This achievement is made possible by two orders of improvement over the currently available methodology First we suggest an approximation to the exact distribution of robust distances flour ...
