Estimation with right‐censored observations under a semi‐Markov model

The semi‐Markov process often provides a better framework than the classical Markov process for the analysis of events with multiple states. The purpose of this paper is twofold. First, we show that in the presence of right censoring, when the right end‐point of the support of the censoring time is strictly less than the right end‐point of the support of the semi‐Markov kernel, the transition probability of the semi‐Markov process is nonidentifiable, and the estimators proposed in the literature are inconsistent in general. We derive the set of all attainable values for the transition probability based on the censored data, and we propose a nonparametric inference procedure for the transition probability using this set. Second, the conventional approach to constructing confidence bands is not applicable for the semi‐Markov kernel and the sojourn time distribution. We propose new perturbation resampling methods to construct these confidence bands. Different weights and transformations are explored in the construction. We use simulation to examine our proposals and illustrate them with hospitalization data from a recent cancer survivor study. The Canadian Journal of Statistics 41: 237–256; 2013 © 2013 Statistical Society of Canada     

The effects of testosterone deficiency on male sexual function

Introduction. Patients with late onset hypogonadism (LOH) also suffered from lower urinary tract symptoms (LUTS) and LOH symptoms. The objects of this study are to evaluate the efficacy of testosterone replace therapy (TRT) by testosterone ointment (Glowmin: GL) for LUTS in LOH patients.

Methods. The Aging Male Symptom (AMS) scale, Medical Outcomes Study (MOS) 36-Item Short-Form Health Survey (SF-36), International Index of Erectile Function (IIEF-5) and the International Prostate Symptom Score (IPSS) were obtained from patients with LOH. A total of 41 patients with LOH have been treated with TRT using 6 mg/day of GL for 3 months. Serum free testosterone levels (FT) and these four scores were compared before and after TRT.

Results. Serum FT levels and the scores for the four parameters of AMS, six of eight domains in SF-36, IIEF-5 and total IPSS improved significantly after 3 months TRT. In addition, all IPSS domains also improved significantly, and voiding disturbance seems to have improved more than storage disturbance (P?=?0.0280 vs. 0.0483).

Conclusion. TRT by administration of GL is considered to be effective in the improvement of not only ED and LOH symptoms, but also LUTS (especially voiding disturbance) of patients with LOH.     

跨国并购与我国企业技术进步的相关性分析

近年来，跨国并购逐渐成为我国企业国际化发展以及构建核心竞争能力的重要途径，而跨国并购能否对我国企业的技术进步起到积极的作用则成为理论研究的热点问题。针对此，采用全要素指标体系，分析了1991~2007年全要素增长率与跨国并购增长率之间的关系，认为:跨国并购的变化对技术进步具有一定的影响关系，但是由于技术并购在对外投资中的比重偏低，过分重视了技术的引进，忽视了技术的吸收消化过程等因素的影响，因此这种影响的效果并不显著。     

从货币职能面分析我国M2/GDP的偏高现象

本文将主要从M2/GDP的两种增长方式和货币的五个基本职能出发,结合货币经济和实体经济的发展,总结我国M2/GDP偏高的原因,货币的僵化和低能是最重要的两个方面,并由此给出相应的政策建议.     

Overdispersed negative binomial regression models

Overdispersion is a common phenomenon in actual data sets. It is important to have methods of dealing with extra variation in regression situations. This article develops tests for extra-negative binomial variation and gives some numerical methods to deal with it. Simulations show power comparisons between some of the overdispersion tests discussed. Finally, an example is given to demonstrate the methods.     

试论李家窑M44墓主身份及西虢东迁问题

李家窑西周44号墓出土铜器之铭文显示的信息是:墓主名叫"追夷",以"宫"为氏,子男一级贵族。结合其他铜器铭文可知,宫氏为姬姓,是西虢小宗。追夷大约在西周末年随其宗子由西虢迁居今三门峡一带。平王东迁,西虢随之东来,便以"宫"氏居地为基础建立了虢国。     

从里尔克的《豹》看抒情主体的结构

在抒情诗中,潜在于诗句之外的第一人称主体不止一个,"抒情主体"也不仅仅要么是对"诗人",要么是对诗歌世界中的某个对象性"人物"的指涉。以《豹》为个案对抒情主体进行的结构分析提示,诗歌中有多个潜在主体的代换。     

Multiple Linear Regression Model Under Nonnormality

Abstract

We consider multiple linear regression models under nonnormality. We derive modified maximum likelihood estimators (MMLEs) of the parameters and show that they are efficient and robust. We show that the least squares esimators are considerably less efficient. We compare the efficiencies of the MMLEs and the M estimators for symmetric distributions and show that, for plausible alternatives to an assumed distribution, the former are more efficient. We provide real-life examples.     

时代主流话语里的艰难表达——浅论肖洛霍夫对孙犁创作的影响

作为20世纪中国文学史上一个颇具个性和复杂性的存在，孙犁显然受到过始终游离于中心和边缘之间的苏联作家肖洛霍夫的影响。孙犁从坚守知识分子独立立场、热烈追求人道主义、深情眷念故土乡亲等三个方面接受和借鉴了肖洛霍夫的人生观和创作经验，进而形成了自己独具特色的创作风格。