Influence diagnostics for the Weibull-Negative-Binomial regression model with cure rate under latent failure causes

In this paper, we propose a flexible cure rate survival model by assuming that the number of competing causes of the event of interest follows the Negative Binomial distribution and the time to event follows a Weibull distribution. Indeed, we introduce the Weibull-Negative-Binomial (WNB) distribution, which can be used in order to model survival data when the hazard rate function is increasing, decreasing and some non-monotonous shaped. Another advantage of the proposed model is that it has some distributions commonly used in lifetime analysis as particular cases. Moreover, the proposed model includes as special cases some of the well-know cure rate models discussed in the literature. We consider a frequentist analysis for parameter estimation of a WNB model with cure rate. Then, we derive the appropriate matrices for assessing local influence on the parameter estimates under different perturbation schemes and present some ways to perform global influence analysis. Finally, the methodology is illustrated on a medical data.     

手机祝福短信与现代人的节日生存状态

本文分析了手机节日祝福短信的娱乐性、“耍贫嘴”现象和机械复制性等文化特征,认为手机节日祝福短信在快速便捷地传递祝福信息的同时,也以虚幻的电子传媒空间代替了情感的直接沟通,以娱乐和搞笑代替了真诚的祝福。手机短信解构了节日的神圣性,对传统的节日生活形成了一定的冲击,使传媒时代的人们变得浮躁和空虚。     

兰陵萧氏宗教信仰转变与时代变迁互动关系初探

兰陵萧氏是中国中古时期显赫的士大夫家族,历经梁、陈、隋、唐400余年,且始终活跃在这个时期上层社会的舞台上。文章对兰陵萧氏家族信仰的形成及变迁做初步探讨,力图揭示以兰陵萧氏为代表的中古士大代夫家族信仰的变迁与中国中古社会政治思想文化变动之间的互动关系。     

Inference on a progressive type I interval-censored truncated normal distribution

In this paper, we consider the problem of making statistical inference for a truncated normal distribution under progressive type I interval censoring. We obtain maximum likelihood estimators of unknown parameters using the expectation-maximization algorithm and in sequel, we also compute corresponding midpoint estimates of parameters. Estimation based on the probability plot method is also considered. Asymptotic confidence intervals of unknown parameters are constructed based on the observed Fisher information matrix. We obtain Bayes estimators of parameters with respect to informative and non-informative prior distributions under squared error and linex loss functions. We compute these estimates using the importance sampling procedure. The highest posterior density intervals of unknown parameters are constructed as well. We present a Monte Carlo simulation study to compare the performance of proposed point and interval estimators. Analysis of a real data set is also performed for illustration purposes. Finally, inspection times and optimal censoring plans based on the expected Fisher information matrix are discussed.     

论中国古代服饰广告的传播特色

中国古代的服饰具有广告的属性和特征,它是古代广告媒介的重要形态之一.中国古代服饰广告历史悠久,并经过了一个漫长的发展和演进过程.中国古代服饰广告丰富多彩,色彩、款式、图案、纹饰等构成服饰广告的主要元素.中国古代服饰广告文化是中国民俗文化的重要组成部分,有着重要的文化意义和社会意义.     

Social Sources of Failure in Education: The Case in East and Southeast Turkey

The efficiency of education in East and Southeast Turkey (E&SE) has long been a subject of debate. Both regions are similar to each other and different from the other regions in terms of economy, culture, ethnic origin, and languages spoken. Sahin (1997) studied the efficiency of education in the E&SE and proposed that illiteracy is significantly the highest in both regions, the female student population is significantly lower, and students are significantly less successful in nationwide general proficiency examinations (OSS and OYS) compared to all the other regions. Social sources of failure were studied in terms of the distinguishing characteristics of both regions, from both practical and theoretical standpoints. The findings indicated inequality of educational opportunity rooted in geographical, economical, social (cultural, linguistic), and political factors.     

Characterizations based on conditional expectations

For given real functionsg andh, first we give necessary and sufficient conditions such that there exists a random variableX satisfying thatE(g(X)|X≥y)=h(y)r _x (y),∀y ∈ C _x , whereC _x andT _X are the support and the failure rate function ofX, respectively. These extend the results of Ruiz and Navarro (1994) and Ghitany et al. (1995). Next we investigate necessary and sufficient conditions such thath(y)=E(g(X)|X≥y), for a given functionh. Support for this research was provided in part by the National Science Council of the Republic of China, Grant No. NSC 86-2115-M-110-014 and NSC 88-2118-M-110-001     

A class of weighted dependence measures for bivariate failure time data

This paper considers a class of summary measures of the dependence between a pair of failure time variables over a finite follow-up region. The class consists of measures that are weighted averages of local dependence measures, and includes the cross-ratio-measure and finite region version of Kendall's τ; recently proposed by the authors. Two new special cases are identified that can avoid the need to estimate the bivariate survivor function and that admit explicit variance estimators. Nonparametric estimators of such dependence measures are proposed and are shown to be consistent and asymptotically normal with variances that can be consistently estimated. Properties of selected estimators are evaluated in a simulation study, and the method is illustrated through an analysis of Australian Twin Study data.     

Semiparametric regression of clustered current status data

This paper discusses regression analysis of clustered current status data under semiparametric additive hazards models. In particular, we consider the situation when cluster sizes can be informative about correlated failure times from the same cluster. To address the problem, we present estimating equation-based estimation procedures and establish asymptotic properties of the resulting estimates. Finite sample performance of the proposed method is assessed through an extensive simulation study, which indicates the procedure works well. The method is applied to a motivating data set from a lung tumorigenicity study.     

Assessing the market values of soccer players – a robust analysis of data from German 1. and 2. Bundesliga

The paper examines to what extent a player's market value depends on his skills. Therefore, a data set covering 28 performance measures and the market values of about 493 players from 1. and 2. German Bundesliga is analysed. Applying robust analysis techniques, we are able to robustly estimate market values of soccer players. The results show (1) that there are significantly underrated and overrated players and (2) that a player's affiliation to a certain team may contribute to his market value. We conclude that a club's reputation affects the market values of its players and that star players are in tendency overrated.