White and nonwhite trends in first birth timing: Comparisons using vital registration and current population surveys

The magnitude of racial differences in first birth timing vary greatly depending upon the data sources from which they are estimated. Vital registration data (Heuser 1976; with updates from the National Center for Health Statistics 1974–1990) show that in recent years nonwhites have higher risks of a first birth at virtually all ages compared to whites. As a result very large and historically novel differentials in childlessness are forecast using these data (see Rindfuss et al. 1988; Chen & Morgan 1991; Morgan & Chen 1992). However, retrospective fertility history data collected from the 1980, 1985 and 1990 Current Population Surveys (CPS) suggest much smaller racial differences in completed childlessness and isolate racial differences in probabilities of first births at young ages. Differences also exist between theses two series for whites prior to the mid-1960s but not afterwards. Reasons for these differing estimates are suggested and examined. We conclude that a substantial portion of the differences result from an accumulation of biases in the vital registration estimates that affect primarily estimates of first birth timing. Thus, the CPS data provide a more firm basis for racial comparisons of first birth timing.     

FORRIDGE - Principles of good practice in material flow

The post World War II Industrial Revolution has driven production away from the old 'economies of scale' to the new 'economies of scope'. Apparently Japanese led, the associated roots of present good practice on material flow can be traced back in the USA to Jay Forrester and in the UK to Jack Burbidge. Specifically, in the supply chain scenario, Forrester exposed the importance of system structure in relating and integrating information flow with material flow. Similarly Burbidge led the way in exploiting cycle time reduction, synchronization of orders throughout the chain, simplified product structures, and streamlined component flows. This paper unites their contributions to material flow engineering and shows how present day system design methodologies incorporate their ideas on best practice. These principles are particularly relevant to the product delivery process (PDP) which governs material flow in supply chains.     

Layered supervisory control architecture for reconfigurable automation

The development of control systems and supporting software remains one of the greatest obstacles to the widespread implementation of highly adaptive reconfigurable automation technology. This paper will present the structure of a modular automation control system designed to support rapid reconfiguration and redeployment of automation components. The paper will first present the concept of a layered system architecture and the use of modular automation components to support the construction of a wide variety of automated systems. This layered system architecture is then applied to the proposed modular supervisory control system responsible for configuring and driving automated production resources. Each of the control components comprising this modular control system will be presented.     

女性社会地位与总和生育率

在审视现有衡量女性社会地位的指标体系并用主成分分析法构建出新的指标体系的基础上,依据联合国人类发展报告中提供的数据,对全世界36个具有代表性的国家的女性社会地位与总和生育率的关系进行了研究分析,对最不发达国家进行了补充性分析。研究表明:一个国家女性的社会地位越高,总和生育率越低;一个国家的妇幼医疗保障水平对该国生育率的变动有着特殊重要的意义。     

Applying State Space to SPC: Monitoring Multivariate Time Series

Monitoring cross-sectional and serially interdependent processes has become a new issue in statistical process control (SPC). In up-to-date SPC literature, Kalman filtering was reported to monitor univariate autocorrelated processes. This paper applies a Kalman filter or state-space method for SPC to monitoring multivariate time series. We use Aoki's approach to estimate the parameter matrices of a state-space model. Multivariate Hotelling T ² control charts are employed to monitor the residuals of the state-space. Examples of this approach are illustrated.     

Employment, family union and childbearing decisions in Great Britain

Summary.  The paper investigates the life-cycle relationship of work and family life in Britain based on the British Household Panel Survey. Using hazard regression techniques we estimate a five-equation model, which includes birth events, union formation, union dissolution, employment and non-employment events. We find that transitions in and out of employment for men are relatively independent of other transitions. In contrast, there are strong links between employment of females, having children and union formation. By undertaking a detailed microsimulations analysis, we show that different levels of labour force participation by females do not necessarily lead to large changes in fertility events. Changes in union formation and fertility events, in contrast, have larger effects on employment.     

Determinants of Contraceptive Use in Egypt: A Multilevel Approach

The increasing use of family planning methods seems to be the intermediate determinant which mostly influences the fertility decline in developing countries, and in particular in those countries which are in an advanced phase of demographic transition such as Egypt. Moreover large countries, like Egypt, are characterized by very different geographical realities and even by strong regional heterogeneities. The aim of this study is the analysis of the determinants of contraceptive use in Egypt, with particular reference to the differentials due to the socio-economic context and to the area of residence. To estimate each individual and regional factors’ effect on contraceptive use, a logistic two-level random intercept model is fitted to EDHS 2000 data; the use of a multilevel analysis is suggested by the two-level data structure: the first level units are the women, the second level units are their regions of residence.     

“森林有害生物控制”教学改革理论与实践

作者针对“森林有害生物控制”课程的特点,将原属于“森林昆虫学”和“林木病理学”两门课程的内容全面整合;进一步改革教学方法,通过使用多媒体技术,提供翔实生动的多媒体资料,提高学生学习的兴趣;充分利用网络工具,增加学生获取信息的途径,体现学生学习的主体地位,增强学生的自学能力;通过教学活动的全程控制,提高学生学习的主动性和积极性。     

示范性数控技术专业建设探索与实践

总结了过去几年来数控技术专业的办学经验和办学成果,找到存在的不足,并对今后的专业建设和教学改革提出了工作设想和未来展望。     

浅析莎剧中的上帝母题

上帝是基督教神学最重要的观念,在基督教信仰中,上帝具有全能的智慧,全在全知;他的旨意决定着一切,世人所能做的只是对他表示无条件的承认和顺从;上帝是仁慈的,对其子民永远表示眷爱;上帝又是公义的,扬善惩恶.在莎士比亚戏剧中,上帝的这些属性得到了充分的展现.文章紧扣圣经文本和剧本内容,对该母题在莎剧中的具体表现作出详尽分析.