-
作者：Efromovich, Sam
作者单位：University of Texas System; University of Texas Dallas
摘要：The theory of adaptive estimation and oracle inequalities for the case of Gaussian-shift-finite-interval experiments has made significant progress in recent years. In particular, sharp-minimax adaptive estimators and exact exponential-type oracle inequalities have been suggested for a vast set of functions including analytic and Sobolev with any positive index as well as for Efromovich-Pinsker and Stein blockwise-shrinkage estimators. Is it possible to obtain similar results for a more interes...
-
作者：Jupp, P. E.
作者单位：University of St Andrews
摘要：Data-driven versions of Sobolev tests of uniformity on compact Riemannian manifolds are proposed. These tests are invariant under isometries; and are consistent against all alternatives. The large-sample asymptotic null distributions are given.
-
作者：Garcia-Escudero, Luis A.; Gordaliza, Alfonso; Matran, Carlos; Mayo-Iscar, Agustin
作者单位：Universidad de Valladolid
摘要：We introduce a new method for performing clustering with the aim of fitting clusters with different scatters and weights. It is designed by allowing to handle a proportion alpha of contaminating data to guarantee the robustness of the method. As a characteristic feature, restrictions on the ratio between the maximum and the minimum eigenvalues of the groups scatter matrices are introduced. This makes the problem to be well defined and guarantees the consistency of the sample solutions to the p...
-
作者：Majumdar, Dibyen; Stufken, John
作者单位：University of Illinois System; University of Illinois Chicago; University of Illinois Chicago Hospital; University System of Georgia; University of Georgia
摘要：We consider experiments for comparing treatments using units that are ordered linearly over time or space within blocks. In addition to the block effect, we assume that a trend effect influences the response. The latter is modeled as a smooth component plus a random term that captures departures from the smooth trend. The model is flexible enough to cover a variety of situations; for instance, most of the effects may be either random or fixed. The information matrix for a design will be a func...
-
作者：Lok, Judith J.
作者单位：Harvard University; Harvard T.H. Chan School of Public Health
摘要：This article studies the estimation of the causal effect of a time-varying treatment on time-to-an-event or on some other continuously distributed outcome. The paper applies to the situation where treatment is repeatedly adapted to time-dependent patient characteristics. The treatment effect cannot be estimated by simply conditioning on these time-dependent patient characteristics, as they may themselves be indications of the treatment effect. This time-dependent confounding is common in obser...
-
作者：Van Der Wart, A. W.; Van Zanten, J. H.
作者单位：Vrije Universiteit Amsterdam
摘要：We derive rates of contraction of posterior distributions on nonparametric or semiparametric models based on Gaussian processes. The rate of contraction is shown to depend on the position of the true parameter relative to the reproducing kernel Hilbert space of the Gaussian process and the small ball probabilities of the Gaussian process. We determine these quantities for a range of examples of Gaussian priors and in several statistical settings. For instance, we consider the rate of contracti...
-
作者：Nardi, Yuval; Siegmund, David O.; Yakir, Benjamin
作者单位：Carnegie Mellon University; Stanford University; Hebrew University of Jerusalem
摘要：Motivated by the problem of testing for the existence of a signal of known parametric structure and unknown location (as explained below) against a noisy background, we obtain for the maximum of a centered, smooth random field an approximation for the tail of the distribution. For the motivating class of problems this gives approximately the significance level of the maximum score test. The method is based on an application of a likelihood-ratio-identity followed by approximations of local fie...
-
作者：Groeneboom, Piet; Maathuis, Marloes H.; Wellner, Jon A.
作者单位：Delft University of Technology; Swiss Federal Institutes of Technology Domain; ETH Zurich; University of Washington; University of Washington Seattle; Vrije Universiteit Amsterdam
摘要：We study nonparametric estimation of the sub-distribution functions for current status data with competing risks. Our main interest is in the nonparametric maximum likelihood estimator (MLE), and for comparison we also consider a simpler naive estimator. Both types of estimators were studied by Jewell, van der Laan and Henneman [Biometrika (2003) 90 183-197], but little was known about their large sample properties. We have started to fill this gap, by proving that the estimators are consisten...
