Temporal pattern in number of staff on sick leave: the effect of downsizing

Summary.  The pattern of absenteeism in the downsizing process of companies is a topic in focus in economics and social science. A general question is whether employees who are frequently absent are more likely to be selected to be laid off or in contrast whether employees to be dismissed are more likely to be absent for the remaining time of their working contract. We pursue an empirical and microeconomic investigation of these theses. We analyse longitudinal data that were collected in a German company over several years. We fit a semiparametric transition model based on a mixture Poisson distribution for the days of absenteeism per month. Prediction intervals are considered and the primary focus is on the period of downsizing. The data reveal clear evidence for the hypothesis that employees who are to be laid off are more frequently absent before leaving the company. Interestingly, though, no clear evidence is seen that employees being selected to leave the company are those with a bad absenteeism profile.     

Causal inference with generalized structural mean models

Summary.  We estimate cause–effect relationships in empirical research where exposures are not completely controlled, as in observational studies or with patient non-compliance and self-selected treatment switches in randomized clinical trials. Additive and multiplicative structural mean models have proved useful for this but suffer from the classical limitations of linear and log-linear models when accommodating binary data. We propose the generalized structural mean model to overcome these limitations. This is a semiparametric two-stage model which extends the structural mean model to handle non-linear average exposure effects. The first-stage structural model describes the causal effect of received exposure by contrasting the means of observed and potential exposure-free outcomes in exposed subsets of the population. For identification of the structural parameters, a second stage 'nuisance' model is introduced. This takes the form of a classical association model for expected outcomes given observed exposure. Under the model, we derive estimating equations which yield consistent, asymptotically normal and efficient estimators of the structural effects. We examine their robustness to model misspecification and construct robust estimators in the absence of any exposure effect. The double-logistic structural mean model is developed in more detail to estimate the effect of observed exposure on the success of treatment in a randomized controlled blood pressure reduction trial with self-selected non-compliance.     

美国与英国公益性科技管理体系研究

从国家科技管理机构、科研体系及公共科研成果转化三个方面分析美国和英国的公益性科技管理制度及其发展变化.随着经济全球化和知识自由流动的发展,科学技术在国家经济发展与社会进步方面的作用越来越大,政府在科技管理上的职能与地位也随之发生变化,总的来说是由原来的主要资助者和实施者转变为催化者和促进者.     

社会转型与先进文化

社会转型为先进化的产生提供了基础，先进化是社会转型成功的客观要求。社会转型决定先进化，先进化又反作用于社会转型。当前中国的快速转型为先进化发挥作用提供了历史舞台，先进化只能服务于建设有中国特色的社会主义的任务，它对当前中国的社会转型起推动作用。发展当代中国的先进化，关键是要从中国先进化的基本内容上搞清楚和把握好主流性、创新性、开放性、先导性、民族性这几个中国先进化建设的重要特点，从而更好地指导当代中国的先进化建设。     

言语生成及理解的心理模型

言语生成 (speechproduction)和言语理解 (speechunderstanding)是语言交际中十分复杂的心理认知过程 ,也是心理语言学研究中的一个重要内容。本文拟对有关言语生成和理解的几种心理模型予以讨论 ,探讨言语生成及理解的过程和实质。     

"城中村"城市化的对策研究

随着城市化速度的加快 ,因城市的扩张产生的“城中村”所造成的社会问题日益突出。本文对“城中村”改造过程中遇到的政策和现实问题进行了剖析 ,认为“城中村”改造的主要困难是社会经济政策滞后问题 ,提出了超前调整政策 ,促进“城中村”改造的思路和对策     

求直射变换的二重元素问题的简便方法

本文对高等几何中直射变换的二重元素的关系进行探索,得出一个求解直射变换的二重元素问题的简便方法.     

大中专在校学生考试分数的正态化线性转换

本文分析了考试记分方法中传统的绝对百分体制的缺陷，给出了一种正态化转换分数的算法，较适合于在校大中专学生学习水平的横向评价。     

密度分布非均匀的反馈控制Logistic单种群模型平衡态的稳定性

本文对种群密度在非均匀分布情形下,考虑了具反馈控制的滞后 Logistic 生态模型平衡位置的稳定性;分别给出了在常时滞和弱连续时滞以及强连续时滞情况下的稳定性条件;其结果是对 Gopalsamy 在密度均匀分布情形下相应结果的推广.     

论曾纪泽的外交思想及实践

曾纪泽是我国近代著名的爱国外交家。中西文化是曾纪泽外交思想的源泉。他是传统外交向近代外交转化的代表人物之一 ,他的外交思想反映了当时中国外交发展的方向。中俄谈判和中法交涉无疑体现了他的外交思想。他既不同于主和派 ,又不同于主战派。