An Asymptotic Analysis of the Logrank Test

Asymptotic expansions for the null distribution of the logrank statistic and its distribution under local proportional hazards alternatives are developed in the case of iid observations. The results, which are derived from the work of Gu (1992) and Taniguchi (1992), are easy to interpret, and provide some theoretical justification for many behavioral characteristics of the logrank test that have been previously observed in simulation studies. We focus primarily upon (i) the inadequacy of the usual normal approximation under treatment group imbalance; and, (ii) the effects of treatment group imbalance on power and sample size calculations. A simple transformation of the logrank statistic is also derived based on results in Konishi (1991) and is found to substantially improve the standard normal approximation to its distribution under the null hypothesis of no survival difference when there is treatment group imbalance. This revised version was published online in July 2006 with corrections to the Cover Date.     

Bias Reduction through First-order Mean Correction, Bootstrapping and Recursive Mean Adjustment

Standard methods of estimation for autoregressive models are known to be biased in finite samples, which has implications for estimation, hypothesis testing, confidence interval construction and forecasting. Three methods of bias reduction are considered here: first-order bias correction, FOBC, where the total bias is approximated by the O(T^-1) bias; bootstrapping; and recursive mean adjustment, RMA. In addition, we show how first-order bias correction is related to linear bias correction. The practically important case where the AR model includes an unknown linear trend is considered in detail. The fidelity of nominal to actual coverage of confidence intervals is also assessed. A simulation study covers the AR(1) model and a number of extensions based on the empirical AR(p) models fitted by Nelson & Plosser (1982). Overall, which method dominates depends on the criterion adopted: bootstrapping tends to be the best at reducing bias, recursive mean adjustment is best at reducing mean squared error, whilst FOBC does particularly well in maintaining the fidelity of confidence intervals.     

农民工大病统筹医疗保险政策分析——以济南市为例

许多地方政府将农民工医疗保险问题提上议程,并出台了不尽相同的医疗保险政策.目前农民工在城市可参加的医疗保险主要有三种:城镇职工基本医疗保险、综合社会保险以及大病统筹医疗保险.本文主要针对实施相对广泛的农民工大病统筹医疗保险政策进行分析,具体以济南市农民工医疗保险政策为例,并在政策分析的基础上提出政策调整的建议.     

论城市土地资源的集约化配置

城市土地资源的集约化配置应坚持的原则是:增加土地的有效供给;实现土地资产综合效益最大化;保持土地资源的永续利用。城市土地的集约化配置需要政府调控与市场机制的结合:政府的主导作用是制定土地利用规划,建立城市土地储备制度以解决市场失灵问题,市场机制的基础作用在于形成利润最大化的土地利用空间。城市土地资源的集约化配置的主要路径是推进城市用地置换,改造旧城区和土地的立体化使用。     

实施科技兴贸战略的问题与建议

指出实施科技兴贸战略的必要性，针对中国科技兴贸战略实施过程中存在的问题，提出进一步落实科技兴贸战略的政策建议。     

“Separation Guilt” in Women Who Initiate Divorce

This paper explores the “separation guilt” of women who initiate divorce. The paper argues that the gender-specific processes of separation individuation and socialization that women undergo in childhood make them vulnerable to similar guilt feelings when they initiate divorce, only towards the husband they are leaving. It further argues that these feelings may impair their post-divorce adjustment. The paper illustrates these points with two case studies, one showing how the woman’s separation guilt thwarted the development of new intimacy, the other showing how it impaired her maternal functioning. Recommendations are made for treatment and research. Nehami Baum Ph.D., is a lecturer at the School of Social Work at Bar Ilan University. She is a social worker with experience in both public and private practice. Her special interests include non-death related loss, divorce, men in therapy, treatment termination, social work students’ professional identity formation, guilt, and social work in times of terror and political tension.     

经济系教学计划和课程体系调整与优化设想

文章简要说明经济系经济学、国际经济与贸易、国际经济与法律三个专业教学计划和课程体系调整与优化的基本原则、主要依据以及具体方案。     

如何调整和深化东北亚双边合作

东北亚区域合作,基于起点比较低,矛盾错综复杂,阻力不断,因此对合作的广度和深度不能要求太多,不能操之过急。多边主义在东北亚区域合作中进展缓慢,没有比较成功的合作实践和模式,耗费了大量资源。因此,东北亚全面区域合作的路程还很漫长,需要集腋成裘,聚沙成塔。对东北亚合作的困难性要有充分的估计,对长期性要有充分的准备。东北亚合作从双边入手,是最具有现实性和可行性的。东北亚的双边主义比全球化和区域主义更具有可操作性。拓展和深化东北亚双边合作模式,应是当前东北亚地区合作的当务之急。     

行政区划调整下的大绍兴规划建设

大绍兴(也称绍北地区)交通方便、城镇密集、人口众多,是绍兴市的政治、经济、文化和科技中心所在地,也是宁绍平原西部的一个重要经济增长极。2013年国务院批准了绍兴市部分行政区划调整方案,使绍北地区迈入了大绍兴建设的新阶段。鉴于行政区划调整的必要性,行政区划调整对大绍兴建设意义重大,大绍兴规划建设可从优化产业结构,构划综合交通设施,提升城市管理水平等方面着手,以促进大绍兴地区持续协调发展。     

开发区发展阶段识别及差异化调控对策研究——以湖南省为例

在文献回顾及相关专家访谈基础上,提出开发区成长指数、成长速度、成长累积的概念,并设计出计算方法,以此对湖南省开发区发展阶段及调控对策进行实证研究。首先划定几个临界值识别开发区发展阶段;然后说明湖南开发区发展呈现的明显的不均匀性;最后基于不同发展阶段特征提出相关差异化调控对策。