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作者:Huang, WZ; Fitzmaurice, GM
作者单位:Harvard University; Harvard T.H. Chan School of Public Health; Harvard University; Harvard University Medical Affiliates; Brigham & Women's Hospital
摘要:The paper considers modelling, estimating and diagnostically verifying the response process generating longitudinal data, with emphasis on association between repeated meas-ures from unbalanced longitudinal designs. Our model is based on separate specifications of the moments for the mean, standard deviation and correlation, with different components possibly sharing common parameters. We propose a general class of correlation structures that comprise random effects, measurement errors and a s...
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作者:Chen, YG; Xie, JY; Liu, JS
作者单位:Harvard University; Duke University
摘要:Motivated by the statistical inference problem in population genetics, we present a new sequential importance sampling with resampling strategy. The idea of resampling is key to the recent surge of popularity of sequential Monte Carlo methods in the statistics and engin-eering communities, but existing resampling techniques do not work well for coalescent-based inference problems in population genetics. We develop a new method called 'stopping-time resampling', which allows us to compare parti...
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作者:Ferreira, JTAS; Steel, MFJ
作者单位:University of Warwick
摘要:We introduce the directionally dispersed class of multivariate distributions, a generalization of the elliptical class. By allowing dispersion of multivariate random variables to vary with direction it is possible to generate a very wide and flexible class of distributions. Directionally dispersed distributions have a simple form for their density, which extends a spherically symmetric density function by including a function D modelling directional dispersion. Under a mild condition, the clas...
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作者:Tibshirani, R; Saunders, M; Rosset, S; Zhu, J; Knight, K
作者单位:Stanford University; International Business Machines (IBM); IBM USA; University of Michigan System; University of Michigan; University of Toronto
摘要:The lasso penalizes a least squares regression by the sum of the absolute values (L-1-norm) of the coefficients. The form of this penalty encourages sparse solutions (with many coefficients equal to 0). We propose the 'fused lasso', a generalization that is designed for problems with features that can be ordered in some meaningful way. The fused lasso penalizes the L-1-norm of both the coefficients and their successive differences. Thus it encourages sparsity of the coefficients and also spars...
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作者:Bladt, M; Sorensen, M
作者单位:University of Copenhagen; Universidad Nacional Autonoma de Mexico
摘要:Likelihood inference for discretely observed Markov jump processes with finite state space is investigated. The existence and uniqueness of the maximum likelihood estimator of the intensity matrix are investigated. This topic is closely related to the imbedding problem for Markov chains. It is demonstrated that the maximum likelihood estimator can be found either by the EM algorithm or by a Markov chain Monte Carlo procedure. When the maximum likelihood estimator does not exist, an estimator c...
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作者:Stein, ML
作者单位:University of Chicago
摘要:Meteorological and environmental data that are collected at regular time intervals on a fixed monitoring network can be usefully studied combining ideas from multiple time series and spatial statistics, particularly when there are little or no missing data. This work investigates methods for modelling such data and ways of approximating the associated likelihood functions. Models for processes on the sphere crossed with time are emphasized, especially models that are not fully symmetric in spa...
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作者:Vovk, V; Shafer, G
作者单位:Rutgers University System; Rutgers University New Brunswick; Rutgers University Newark; University of London; Royal Holloway University London
摘要:Building on the game theoretic framework for probability, we show that it is possible, using randomization, to make sequential probability forecasts that will pass any given battery of statistical tests. This result, an easy consequence of von Neumann's minimax theorem, simplifies and generalizes work by earlier researchers.
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作者:Chiou, JM; Müller, HG
作者单位:University of California System; University of California Davis; Academia Sinica - Taiwan
摘要:We introduce a flexible marginal modelling approach for statistical inference for clustered and longitudinal data under minimal assumptions. This estimated estimating equations approach is semiparametric and the proposed models are fitted by quasi-likelihood regression, where the unknown marginal means are a function of the fixed effects linear predictor with unknown smooth link, and variance-covariance is an unknown smooth function of the marginal means. We propose to estimate the nonparametr...
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作者:Kendall, WS; Renshaw, E; Lawson, A; Mateu, J; Saura, F; Harding, EF; Stoyan, D; Zhuang, JC; Besag, J; Diggle, P; Fearnhead, P; Geyer, CJ; Grabarnik, P; Ogata, Y; Schoenberg, FP; Waagepetersen, R
作者单位:University of Warwick; University of Strathclyde; University of South Carolina System; University of South Carolina Columbia; Universitat Jaume I; Technical University Freiberg; Chalmers University of Technology; Research Organization of Information & Systems (ROIS); Institute of Statistical Mathematics (ISM) - Japan; University of Washington; University of Washington Seattle; Lancaster University; University of Minnesota System; University of Minnesota Twin Cities; Russian Academy of Sciences; University of California System; University of California Los Angeles; Aalborg University
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作者:Artiles, LM; Gill, RD; Guta, MI
作者单位:Utrecht University
摘要:We describe quantum tomography as an inverse statistical problem in which the quantum state of a light beam is the unknown parameter and the data are given by results of measurements performed on identical quantum systems. The state can be represented as an infinite dimensional density matrix or equivalently as a density on the plane called the Wigner function. We present consistency results for pattern function projection estimators and for sieve maximum likelihood estimators for both the den...