Multiple event times in the presence of informative censoring: modeling and analysis by copulas

Motivated by a breast cancer research program, this paper is concerned with the joint survivor function of multiple event times when their observations are subject to informative censoring caused by a terminating event. We formulate the correlation of the multiple event times together with the time to the terminating event by an Archimedean copula to account for the informative censoring. Adapting the widely used two-stage procedure under a copula model, we propose an easy-to-implement pseudo-likelihood based procedure for estimating the model parameters. The approach yields a new estimator for the marginal distribution of a single event time with semicompeting-risks data. We conduct both asymptotics and simulation studies to examine the proposed approach in consistency, efficiency, and robustness. Data from the breast cancer program are employed to illustrate this research.

     

二元方程式F(x,y)=0确定的函数曲线渐近线的探讨

给出二元方程式F(x,y)=0确定的函数曲线渐近线的几个结果。     

李贺和比喻

李贺的比喻和一般比喻差别很大,他经常颠倒喻词和被喻词之间的关系,给人带来震撼。这种比喻方法,不仅表现了李贺心中万物平等的思想,也展现了迥异现实的另一世界的景象。     

Zimbabwe's AIDS action programme for schools

AIDS education started very early in Zimbabwe and is now compulsory in all schools. This evaluation documents the development of the primary and secondary school AIDS Action Programme from 1991 to 1998. Six programme aspects were evaluated: programme start-up, planning and management, development of syllabi and materials, teacher training, research, monitoring and evaluation, and co-ordination. The Programme drew on resources from within the existing educational system. Due to broad-based consultation and participation, it was supported by Government and partners. Flexible management ensured implementation of mid-course corrections. It was concluded that school AIDS programmes should stress participatory teaching and learning methods and life-skills training. Curriculum writers and teachers needed training and supervision in participatory techniques. Cluster workshops between district and school levels were needed to strengthen the cascade model of teacher training that had been adopted. Systematic research, monitoring and evaluation were essential, including follow-ups to baseline surveys. The Zimbabwean programme was well-designed, relatively inexpensive and replicable.     

Factors Associated with Having Flextime: A Focus on Married Workers

To examine flexible work scheduling of married workers a conceptual framework was developed and tested using the 1997 Current Population Survey Work Schedules Supplement. Odds of flextime use were higher for married males, non-Hispanic whites, those with relatively higher levels of education and income, those with a preschool aged child, residents of the Midwest or West (as compared with the South), managers or professionals, and employees of the federal government.     

The transition to parenthood in Puerto Rico: Occupational status and the timing of first births

This study examines the relationship between occupational status and fertility timing during a period of rapid development in Puerto Rico. Our fundamental hypothesis is that women with higher status occupations face greater opportunity costs than those with less valued jobs and therefore will be more likely to postpone parenthood until later ages than women without such high costs. We test this hypothesis using event history techniques with data from the 1982 Puerto Rico Fertility and Family Planning Assessment, an island-wide survey of women between the ages of 15 and 49. The analysis examines the effects of occupational status on the timing of first births, and finds strong support for the basic hypothesis, especially regarding the post-ponement of teen births. After the teen years, the effects are less pronounced. Overall, it appears that employment opportunities have played an important role in childbearing decisions in Puerto Rico.An earlier version of this paper was presented at the annual meeting of the Population Association of America, Denver, Colorado, 30 April–2 May 1992.     

Sex differences in nonverbal expressiveness: Emotional expression,personality, and impressions

Sex differences in expressiveness are well documented, but the reasons for and correlates of these important differences are not well studied. A comprehensive set of emotion-relevant personality measures was administered to 40 female and 39 male undergraduate participants, who were also videotaped in three situations: engaging in natural social interaction, describing a past emotional experience, and posing various emotions. Videotapes were judged by sets of naive observers as to emotion communicated and overall impression. Expressive females, who appeared friendly and dominant in social interaction, were found to have a hostile/aggressive personality (but this was not true of males). Expressive females also tended to look angry/disgusted when describing happy and sad experiences. The findings suggest that nonverbally skilled, charismatic women (but not men) may often possess a dominant/aggressive but self-controlled personality, in a new twist on the theory that sex differences in expressiveness result in part from the oppression of women in society.This research was supported in part by an intramural research grant from University of California, Riverside.     

数字化和人工智能对刑事责任的扩散

数字化和人工智能在很大程度上作用于刑法中的罪责并改变了个人责任的基本概念。对于人类与机器人和人工智能系统之间的合作,要在个案中详细地审查：机器如何参与决定的作出,人类的行为空间如何发挥作用,以及个人的罪责是否被阻却或至少被极大地减轻。完全或在部分范围内让机器作出决定,会对罪责概念以及进一步对刑事责任产生许多问题,包括过失犯的预见可能性、客观归责、不当行为的可证明性等。在刑法上进行新的调整可能是有必要的,这涉及罪责、可归责性、可证明性和量刑,同时必须寻找刑法以外的其他解决方案,以持续防止数字化和人工智能系统对刑事责任的扩散。