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.

     

Applying kaizen to the schedule in a concurrent environment

Not only ETO (Engineering to Order), but even serial production industry should know how to deal with projects and their schedule: plant commissioning, shutdown, introducing new products and similar circumstances should be managed with adequate planning and resource allocation techniques to create a schedule useful in decision making during the execution. The current complex reality, with evolving technologies and fierce pressure to reach the market as soon as possible, pushes the project managers to use more advanced techniques than waterfall planning, such as agile or lean. It also requires them to take a holistic view and manage concurrent tasks in complex projects. The contributions of this paper are two: the proposal to control specific parallel groups of waterfall activities under uncertain environments, which can lead to iterations and reworks, as a single concurrent Activity Managed by Kanban Methods (AMKM). This activity can be subsequently embedded into traditional scheduling approaches as CPM-PERT. The second contribution is the feasibility of its application in industrial environments due to the affordability of simulation software. Two use cases are shown as evidence. It is not a disruptive proposal, but a kaizen action based on very mature technologies. Finally, it is suggested some improvements to be implemented in Project Management Software due to this ‘kaizen’ proposal.     

Transparency and Accountability Practices of Local Government Units in the Philippines: a Measurement from the Ground

Public Organization Review - The organizational practices of government personnel are indispensable components of building public trust and confidence. The 56 department heads and 662 personnel...     

International and intercultural issues in English teaching textbooks: the case of Spain

The sociocultural content of foreign language textbooks has become a concern of scholars and practitioners owing to the fact that the traditional emphasis on purely linguistic issues has been expanded to embrace a language in context approach. This paper studies the English‐speaking communities that are described in English language teaching textbooks marketed in Spain. It examines to what extent an international and/or intercultural approach is a constituent element in their design.     

Multivariate distributions defined in terms of contours

The paper deals with the problem of using contours as the basis for defining probability distributions. First, the most general probability densities with given contours are obtained and the particular cases of circular and elliptical contours are dealt with. It is shown that the so-called elliptically contoured distributions do not include all possible cases. Next, the case of contours defined by polar coordinates is analyzed including its simulation and parameter estimation. Finally, the case of cumulative distribution functions with given contours is discussed. Several examples are used for illustrative purposes.     

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.