Computationally Efficient Estimation for the Generalized Odds Rate Mixture Cure Model With Interval-Censored Data

For semiparametric survival models with interval-censored data and a cure fraction, it is often difficult to derive nonparametric maximum likelihood estimation due to the challenge in maximizing the complex likelihood function. In this article, we propose a computationally efficient EM algorithm, facilitated by a gamma-Poisson data augmentation, for maximum likelihood estimation in a class of generalized odds rate mixture cure (GORMC) models with interval-censored data. The gamma-Poisson data augmentation greatly simplifies the EM estimation and enhances the convergence speed of the EM algorithm. The empirical properties of the proposed method are examined through extensive simulation studies and compared with numerical maximum likelihood estimates. An R package “GORCure” is developed to implement the proposed method and its use is illustrated by an application to the Aerobic Center Longitudinal Study dataset. Supplementary material for this article is available online.     

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比例机率模型在生存数据分析中发挥着重要作用. 在本文中, 我们建立了此模型的一些随机比较和年龄性质的结果. 所得结果很好的补充和扩展了Kirmani and Gupta,(2001)中的相关结果.     

圆筒中炸药装药的爆速估算方法探讨

在圆筒试验中利用光光源药柱激发氩气发光所用时间与圆筒装药中爆轰波传到摄像位的时间之差来估算圆筒中炸药的爆速 ,并计算了两发TNT炸药圆筒中的爆速。结果表明 ,该方法准确程度较高 ,而且测试简便 ,能够应用于实际。     

Stochastic comparisons of lifetimes of series and parallel systems with dependent and heterogeneous components

This work considers stochastic comparisons of lifetimes of series and parallel systems with dependent and heterogeneous components having lifetimes following the proportional odds (PO) model. The joint distribution of component lifetimes is modeled by Archimedean survival copula. We discuss some potential applications of our findings in system reliability and actuarial science.     

The Mantel-Haenszel estimator adapted for complex survey designs is not dually consistent

We show via simulation and counterexamples that the Mantel-Haenszel estimator of a common odds ratio, adapted for complex survey designs using survey weights, is inconsistent for sparse-data limiting models. We also propose an alternative estimator that is consistent for sparse-data limiting models satisfying a positivity condition, but not for large-strata limiting models.     

比例优势模型在多结局区间截断数据上的应用

探索比例优势模型在临床医学中常见的多结局区间截断数据中的应用.用条件的逻辑回归方法避免讨厌参数的估计,用牛顿-拉普森算法估计回归系数,用＂夹心方差＂估计量作为参数方差的估计.通过随机模型检验模型应用的有效性.     

ROC曲线在累积比数logit判别模型效果评价中的应用

目的:应用ROC曲线图评价累积比数logit判别模型的效果。方法:介绍ROC分析的原理,并应用其对医学生睡眠质量的累积比数logit判别模型进行评价。结果:ROC曲线较凸,曲线下面积的可信区间不包括0.5,结论:采用ROC曲线来评价累积比数logit判别模型,综合了灵敏度和特异度两个指标,可以全面反映模型的判别效果,比较科学。     

马赛中的博弈

本文利用Shannon最优双倍率计算公式,研究马民财富的增长方式,并结合香港马赛的一个实例,分析马民的财富变化趋势。     

Possible superiority of the conditional MLE over the unconditional MLE

The possibility that the conditional maximum likelihood estimator (CMLE) is superior to the unconditional maximum likelihood estimator (UMLE) is discussed in examples where the residual likelihood is obstructive. We observe relatively smaller risks of the CMLE for a finite sample size. The models in the study include the normal, inverse Gauss, gamma, two-parameter exponential, logit, negative binomial and two-parameter geometric ones.     

Power Divergence Family of Tests for Categorical Time Series Models

A fundamental issue that arises after fitting a regression model is that of testing the goodness of the fit. Our work brings together the power divergence family of goodness of fit tests and regression models for categorical time series. We show that under some reasonable assumptions, the asymptotic distribution of the power divergence family of goodness of fit tests converges to a normal random variable. This fact introduces a novel method for carrying out goodness of fit tests about a regression model for categorical time series. We couple the theory with some empirical results.