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作者：Peel, D; Whiten, WJ; McLachlan, GJ
作者单位：University of Queensland
摘要：When examining a rock mass, joint sets and their orientations can play a significant role with regard to how the rock mass will behave. To identify joint sets present in the rock mass, the orientation of individual fracture planer can be measured on exposed rock faces and the resulting data can be examined for heterogeneity. In this article, the expectation-maximization algorithm is used to lit mixtures of Kent component distributions to the fracture data to aid in the identification of joint ...
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作者：Ishwaran, H; James, LF
作者单位：Cleveland Clinic Foundation; Johns Hopkins University
摘要：A rich and flexible class of random probability measures, which we call stick-breaking pliers, can be constructed using a sequence of independent beta random variables. Examples of random measures that have this characterization include the Dirichlet process, its two-parameter extension, the two-parameter Poisson-Dirichlet process, finite dimensional Dirichlet priors, and beta two-parameter processes. The rich nature of stick-breaking priors offers Bayesians a useful class of priors for nonpar...
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作者：Lin, DY; Ying, Z
作者单位：University of North Carolina; University of North Carolina Chapel Hill; Columbia University
摘要：This article deals with the regression analysis of repeated measurements taken at irregular and possibly subject-specific time points. The proposed semiparametric and nonparametric models postulate that the marginal distribution for the repeatedly measured response variable Y at time t is related to the vector of possibly time-varying covariates X through the equations E{Y(t)\X(t)} = alpha (0)(t) + beta'X-0(t) and E{Y(t)\X(t)\} = alpha (0)(t) + beta'(0)(t)X(t), where alpha (0)(t) is an arbitra...
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作者：Yee, TW; Wild, CJ
作者单位：University of Auckland
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作者：Irizarry, RA
作者单位：Johns Hopkins University
摘要：Local likelihood estimation has proven to be an effective method for obtaining estimates of parameters that vary with a covariate. To obtain useful estimates of such parameters, approximating models are used. In such cases it is useful to consider window based estimates. We may need to choose between competing approximating models. In this article, we propose a modification to the methods used to motivate many information and posterior probability criteria for the weighted likelihood case. We ...
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作者：Larsen, MD; Rubin, DB
作者单位：University of Chicago; Harvard University
摘要：The goal of record linkage is to link quickly and accurately records that correspond to the same person or entity. Whereas certain patterns of agreements and disagreements on variables are more likely among records pertaining to a single person than among records for different people, the observed patterns for pairs of records can be viewed as arising from a mixture of matches and nonmatches. Mixture model estimates can be used to partition record pairs into two or more groups that can be labe...
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作者：Lin, XH; Carroll, RJ
作者单位：University of Michigan System; University of Michigan; Texas A&M University System; Texas A&M University College Station; Texas A&M University System; Texas A&M University College Station
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作者：Herring, AH; Ibrahim, JG
作者单位：University of North Carolina; University of North Carolina Chapel Hill; Harvard University; Harvard T.H. Chan School of Public Health; Harvard University; Harvard University Medical Affiliates; Dana-Farber Cancer Institute
摘要：Problems associated with missing covariate data are well known but often ignored. We present a method for estimating the parameters in the Cox proportional hazards model when the missing data are missing at random (MAR) and censoring is noninformative. Due to the computational burden of this method, we introduce an approximation that allows us to use a weighted expectation-maximization (EM) algorithm to estimate the parameters more easily. When the missing covariates are continuous rather than...
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作者：Hoover, DR; Wu, CO
作者单位：Rutgers University System; Rutgers University New Brunswick; Johns Hopkins University
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作者：Chen, JH; Shao, J
作者单位：University of Waterloo; University of Wisconsin System; University of Wisconsin Madison
摘要：Nearest-neighbor imputation is a popular hot deck imputation method used to compensate for nonresponse in sample surveys. Although this method has a long history of application, the problem of variance estimation after nearest-neighbor imputation has not been fully investigated. Because nearest-neighbor imputation is a nonparametric method, a nonparametric variance estimation technique, such as the jackknife, is desired. We show that the naive jackknife that treats imputed values as observed d...
