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作者：RAO, JNK; KOVAR, JG; MANTEL, HJ
作者单位：Statistics Canada
摘要：Ratio and difference estimators of a population distribution function under a general sampling design are obtained, using auxiliary population information. The relative mean errors and relative mean square errors of these estimators and a model-based estimator of Chambers and Dunstan (1986) are compared through a simulation study. The advantages of the design-based estimators over the model-based estimator under model misspecifications, especially for large samples, are demonstrated. Ratio and...
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作者：BEDRICK, EJ; HILL, JR
摘要：We consider exact conditional methods for identifying outliers in logistic regression data. Tests for a single outlier and multiple outliers are developed assuming a logistic slippage model. The p-values for these tests are determined using an explicit enumeration of all possible responses consistent with the observed value of the sufficient statistic. Justifications are given for preferring this computationally intensive approach to standard methods based on asymptotic approximations. The tec...
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作者：WEI, LJ; YING, Z; LIN, DY
作者单位：University of Illinois System; University of Illinois Urbana-Champaign; University of Washington; University of Washington Seattle
摘要：Recently linear rank statistics with censored data have been used as the estimating functions for the regression parameters in the linear model with an unspecified error distribution. The resulting rank estimators are consistent and asymptotically normal. However, the asymptotic variances of these estimators are complicated and are difficult to estimate well with censored data. In this paper, we propose some simple methods for making inference about a subset of the regression coefficients whil...
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作者：ZHAO, LP; PRENTICE, RL
摘要：A model of quadratic exponential form is parameterized in terms of marginal means and pairwise correlations for the regression analysis of correlated binary data. Pseudo-maximum likelihood methods using a special case termed the multiplicative model are proposed, but are noted to be computationally unattractive if the ''blocks'' of correlated responses are at all large. On the other hand score estimating functions for mean and correlation parameters are shown to be of a particularly simple for...
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作者：HEATHCOTE, CR; NICHOLLS, DF
摘要：The contact rate and associated contact number determine the rate of spread of an infectious disease whose population dynamics are described by a mathematical model. It is shown how to obtain least-squares estimates of the contact rate for a standard homogenous univariate model and a four-group model with different contact rates between the groups. The results of a small scale simulation are presented in the case of the four-group model. It is argued that the least-squares method provides gene...
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作者：SCHAID, DJ; WIEAND, S; THERNEAU, TM
摘要：A two-stage design is presented which enables the screening, at the first stage, of several new experimental treatments for survival improvement over a standard regimen. Only promising treatments are carried forward to the second stage for definitive evaluation. Our procedure is to minimize the number of patients expected to be accrued to new regimens which do not offer a survival benefit over the standard regimen, subject to constraints of specified alpha-error, power, and a stopping rule whi...
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作者：FONG, WK
摘要：To study time-dependent characteristics of a population, we may sample the same population at regular intervals. A basic problem is how the sample should be selected at different time periods. Here we consider successive sampling with partial replacement of units on two occasions from a Bayesian point of view. Bayes estimators and optimal designs for such priors will be obtained. In one situation, the whole survey, i.e. the first sample and the second sample, is planned before the first time p...
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作者：POLSON, N; WASSERMAN, L
摘要：We derive prior distributions for the bivariate binomial model using Bernardo''s (1979) method. These priors are compared to the Jeffreys to a prior and prior proposed by Crowder and Sweeting (1989). The priors possess desirable symmetry properties since we allow them to depend on the parameter of interest.
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作者：ROTNITZKY, A; JEWELL, NP
作者单位：University of California System; University of California Berkeley; University of California System; University of California Berkeley
摘要：Generalized and ''working''Wald and score tests for regression coefficients in the class of semiparametric marginal generalized linear models for cluster correlated data (Liang and Zeger, 1986) are proposed, and their asymptotic distribution examined. In addition, the asymptotic distribution of the naive likelihood ratio test, or deviance difference, is presented. Following Rao and Scott (1984), we propose simple adjustments to such ''working'' tests. The asymptotic distributions of the ''work...
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作者：THERNEAU, TM; GRAMBSCH, PM; FLEMING, TR
作者单位：University of Washington; University of Washington Seattle
摘要：Graphical methods based on the analysis of residuals are considered for the setting of the highly-used Cox (1972) regression model and for the Andersen-Gill (1982) generalization of that model. We start with a class of martingale-based residuals as proposed by Barlow and Prentice (1988). These residuals and/or their transforms are useful for investigating the functional form of a covariate, the proportional hazards assumption, the leverage of each subject upon the estimates of .beta., and the ...
