EFFECTS OF EXPOSURE ON PREVALENCE AND CUMULATIVE RELATIVE RISK: DIRECT AND INDIRECT EFFECTS IN A RECURSIVE HAZARD MODEL

This paper outlines decomposition methods for assessing how exposure affects prevalence and cumulative relative risk. Let     x     denote a vector of exogenous covariates and suppose that a single dimension of time   t   governs two event processes     T ₁  and   T ₂.    If the occurrence of the event     T ₁    determines entry into the risk of the event     T ₂,    then subgroup variation in     T ₁    will affect the prevalence     T ₂,    even if subgroups in the population are otherwise identical. Although researchers often acknowledge this phenomenon, the literature has not provided procedures to assess the magnitude of an exposure effect of     T ₁    on the prevalence of     T ₂.    We derive decompositions that assess how variation in exposure generated by direct and indirect effects of the covariates     x     affect measures of absolute and relative prevalence of     T ₂.    We employ a parametric but highly flexible specification for baseline hazard for the     T ₁  and   T ₂    processes and use the resulting parametric proportional hazard model to illustrate the direct and indirect effects of family structure when     T ₁    is age at first sexual intercourse and     T ₂    is age at a premarital first birth for data on a cohort of non-hispanic white U.S. women.     

A Risk Analysis Model in Concurrent Engineering Product Development

Concurrent engineering has been widely accepted as a viable strategy for companies to reduce time to market and achieve overall cost savings. This article analyzes various risks and challenges in product development under the concurrent engineering environment. A three‐dimensional early warning approach for product development risk management is proposed by integrating graphical evaluation and review technique (GERT) and failure modes and effects analysis (FMEA). Simulation models are created to solve our proposed concurrent engineering product development risk management model. Solutions lead to identification of key risk controlling points. This article demonstrates the value of our approach to risk analysis as a means to monitor various risks typical in the manufacturing sector. This article has three main contributions. First, we establish a conceptual framework to classify various risks in concurrent engineering (CE) product development (PD). Second, we propose use of existing quantitative approaches for PD risk analysis purposes: GERT, FMEA, and product database management (PDM). Based on quantitative tools, we create our approach for risk management of CE PD and discuss solutions of the models. Third, we demonstrate the value of applying our approach using data from a typical Chinese motor company.     

中华姓氏源流研究与中国社会史史料的利用和开发——以中华彭姓源流为例

本文以中华彭姓源流研究为例,认为中华姓氏源流研究也属于中国社会史研究的范畴,因而这项研究的资料利用和开发也与中国社会史史料的利用与开发密切相关.在从事诸如此类研究的同时所积累的第一手资料,在利用和开发此类课题的资料时所得到的体会,也有助于丰富和认识中国社会史史料的利用和开发,有助于中国社会史史料学学科的建设.     

山西黄土CBR的影响分析

在山西省选取5种典型黄土，采用室内试验方法，制备不同击实次数，不同含水量的试件用于CBR值的测定，分析含水量和压实度对黄土填料CBR值的影响，并建立了CBR与含水量的相关关系式。试验结果表明：含水量对CBR值的影响程度最大，在最佳含水量，最大压实度条件下的CBR值最大，含水量越大，击实次数对CBR值的提高效果甚微。随着击实次数的增大，浸水 CBR和不浸水CBR与含水量的相关关系都呈现一定的规律性。     

广东农村妇女妇女病检查影响因素及对策

妇女病不但危害育龄妇女的生殖健康，影响生命质量，还对家庭和谐幸福及社会整体健康水平带来负面影响。在农村妇女中开展妇科疾病定期检查是政府作为关注和保障民生、使广大妇女广泛而长久受惠的一项重要战略举措。因此，广东现行农村妇科病普查是否科学、合理，如何才能提高广大农村妇女妇科病的普查率，是政府十分关注的议题。     

正邪两赋说与《红楼梦》的写情策略

贾雨村的正邪两赋说和秦可卿的卧室意象不仅昭示着<红楼梦>人物形象的谱系渊源,而且作为<红楼梦>的写情策略贯穿于整部小说的内在肌理中.大观园的世界也是一个正邪两赋的世界.在<红楼梦>的神道设教叙事策略中,秦可卿这个人物远远超越了道德层面,具有写意的特征,曹雪芹塑造这个人物时其关注焦点与其说是道德,不如说是生命本身.正邪两赋的历史谱系在小说中一直被当作贾宝玉和群钗情感世界的祖先和偶像,成为<红楼梦>情节设计和人物设计中的重要组成部分,用以展示大观园诸艳的情缘体验.<红楼梦>并不是一部通俗小说,而应该是一部抒情体小说.诗性叙事,是<红楼梦>叙事上的本质特征.     

过渡语僵化现象对英语教学的启示

本文对过渡语僵化现象进行分析，并提出了帮助学习者防止和突破僵化的策略。     

谢灵运诗歌的用典特色辨析

今人多批评谢灵运诗歌用典繁密,但梳理南朝直至唐代的许多关涉前代诗文用典的文论,对于谢诗用典特色非但未见非议之评,甚至多所称赞。明清论者在涉及谢诗用典问题时,也还是褒多于贬,极少诟病的。这种分歧的产生当主要源于诗歌用典判断标准的时代差异。客观地历史地来考察,谢灵运与同时代其他诗人相比,不仅在用典的数量上远远少于颜延之等人,其"用人若己"的特色使得他作品中的许多典故常常不易被察觉,更遑论"繁密"了。     

Extreme statistics from the cosine distribution

The cosine distribution serves as a very good teaching example for which exact moment properties of extreme order statistics can be expressed in terms of elementary functions. This article presents the limiting joint distribution of the extreme order statistics for the cosine distribution. It is shown that burrows'(1986) result is a special case of the result presented in this article.