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拟似然与 EM 算法的推广AI 解读

SUMMARY This paper is concerned with situations in which there are missing or otherwise incomplete data and the full likelihood may not be available. Extensions of the EM algorithm are developed to deal with estimation via general estimating functions and in particular the quasi-score. The E-step is replaced by projecting the quasi-score and the M-step requires the solution of an estimating equation. The standard EM algorithm can be obtained as a particular case if the…

约束拟似然估计AI 解读

For maximum likelihood or least squares parameter estimation subject to a constrained parameter, the standard approach is to use the method of Lagrange multipliers. In this paper it is shown that the same formal procedure applies very generally for constrained quasi-likelihood estimation even though there is ordinarily no objective function to maximize or minimize. This allows for optimal estimation in a wide range of problems where maximum likelihood cannot be used, such as…

受约束的拟似然估计AI 解读

For maximum likelihood or least squares parameter estimation subject to a constrained parameter, the standard approach is to use the method of Lagrange multipliers. In this paper it is shown that the same formal procedure applies very generally for constrained quasi-likelihood estimation even though there is ordinarily no objective function to maximize or minimize. This allows for optimal estimation in a wide range of problems where maximum likelihood cannot be used, such as…

生命表回归分析及相关非参数检验AI 解读

Cox (1972) proposed a regression model for life tables and derived certain hypothesis testing procedures. If there is no censoring and we wish to test a simple null hypothesis, his test statistic is similar to a permutation test. This relation is explored and it is shown how to modify any rank test to allow for censored data. Cox's test and the log rank test are compared and it is concluded that if no censoring occurs the nonparametric test is to be preferred if the sample…

生命表回归分析及相关非参数检验AI 解读

Cox (1972) proposed a regression model for life tables and derived certain hypothesis testing procedures. If there is no censoring and we wish to test a simple null hypothesis, his test statistic is similar to a permutation test. This relation is explored and it is shown how to modify any rank test to allow for censored data. Cox's test and the log rank test are compared and it is concluded that if no censoring occurs the nonparametric test is to be preferred if the sample…