Expected sample moments of concomitants of selected order statistics

In this paper, the task of determining expected values of sample moments, where the sample members have been selected based on noisy information, is considered. This task is a recurring problem in the theory of evolution strategies. Exact expressions for expected values of sums of products of concomitants of selected order statistics are derived. Then, using Edgeworth and Cornish-Fisher approximations, explicit results that depend on coefficients that can be determined numerically are obtained. While the results are exact only for normal populations, it is shown experimentally that including skewness and kurtosis in the calculations can yield greatly improved results for other distributions.     

The Ecology of Family Guidance in Low-Income Mexican-American and European-American Families*

This two-part study applied an ecocultural perspective to socialization of daily and long-term goals in low-income Mexican-American and European-American families with children in third, fifth, and seventh grades. The first part of the study examined family members' participation and parents' socialization goals and guidance strategies for their children's daily household chores and homework activities. The second part of the study examined parents' long-term aspirations and guidance strategies for their children's educational, vocational, and moral development. For daily activities, results showed that in Mexican-American families both parents and siblings played important roles, whereas in European-American families parents were the primary socialization agents. As predicted, in both groups parents' expertise influenced their guidance strategies. Finally, Mexican-American and European-American parents differed in their relative endorsement of gender, relational, and self-reliance goals for household chores. For long-term goals, parents in both groups held high educational, vocational, and moral aspirations for their children. However, some parents of seventh-graders had lower educational and vocational aspirations than those of fifth- and third-graders. Although expertise consistently influenced Mexican-American parents' guidance strategies, the pattern for European-American parents was mixed. The discussion highlights between- and within-group differences in daily and long-term socialization practices with an emphasis on resources and vulnerabilities in the families.     

Age difference asymmetry and a two-sex perspective

The paper shows that (a) the age difference between spouses can be and has been different for men and women; (b) male and female age differences can exhibit different trends; (c) the discrepancy is due to remarriage; (d) the age difference fluctuates substantially through time; (e) trends in the age difference are not readily interpretable as reflecting change in the relative status of the sexes; and (f) that trends in the age difference may be linked to marriage market conditions. The paper argues that marriage and fertility data for both men and women are increasingly necessary because of rises in marital breakdown and the associated divergence of the experience of men and women.Cet article montre que (a) les différences d'âge entre époux peuvent être et ont été dissemblables pour les hommes et les femmes; (b) les différences d'âge masculines et féminines peuvent présenter des tendances différentes; (c) la divergence est due aux remariages; (d) les différences d'âge varient de façon importante au cours du temps; (e) les tendances dans les différences d'âge ne sont pas simplement interprétables en termes de changements dans le statut relatif des sexes; et (f) les tendances dans les différences d'âge peuvent être reliées aux conditions du marché matrimonial. L'article montre que les données sur le mariage et la fécondité à la fois des hommes et des femmes, sont de plus en plus nécessaires du fait de l'accroissement des ruptures d'unions et de la divergence des expériences masculines et féminines, qui lui est associée.

---

An earlier version of this paper, His and her age gap: asymmetry in the age difference between partners, was a contributed paper to Session F27 of the General Conference of the International Union for the Scientific Study of Population, New Delhi, 20–27 September 1989. A longer version appeared as LS Working Paper 70, issued by City University Social Statistics Research Unit, September 1990.     

Dynamic reliability models with conditional proportional hazards

A dynamic approach to the stochastic modelling of reliability systems is further explored. This modelling approach is particularly appropriate for load-sharing, software reliability, and multivariate failure-time models, where component failure characteristics are affected by their degree of use, amount of load, or extent of stresses experienced. This approach incorporates the intuitive notion that when a set of components in a coherent system fail at a certain time, there is a jump from one structure function to another which governs the residual lifetimes of the remaining functioning components, and since the component lifetimes are intrinsically affected by the structure function which they constitute, then at such a failure time there should also be a jump in the stochastic structure of the lifetimes of the remaining components. For such dynamically-modelled systems, the stochastic characteristics of their jump times are studied. These properties of the jump times allow us to obtain the properties of the lifetime of the system. In particular, for a Markov dynamic model, specific expressions for the exact distribution functions of the jump times are obtained for a general coherent system, a parallel system, and a series-parallel system. We derive a new family of distribution functions which describes the distributions of the jump times for a dynamically-modelled system.     

Going to Pieces: Paul Monette and the Fragments of the Tribe

Author of the highly acclaimed Borrowed Time: An AIDS Memoir (1988) and winner of the 1992 National Book Award for his autobiography Becoming a Man: Half a Life Story, Paul Monette died of complications from AIDS in Los Angeles on February 12, 1995. His most recent work, Last Watch of the Night: Essays Too Personal and Otherwise (1994), is his third volume in a trilogy of autobiographical writing on growing up gay, coming-out, and living with AIDS. A graduate of Phillips Academy and Yale University, Monette received a number of awards for his writing and his work as an outspoken voice in the battle against AIDS, including the National Book Award, three Lambda Literary awards, the PEN Center West Freedom to Write Award, and three honorary doctorate degrees, from Wesleyan University, the City University of New York, and the State University of New York at Oswego. A memorial service was held for Monette on Sunday, February 19, 1995, at the Directors Guild of America on Sunset Boulevard in Los Angeles. Paul Monette was 49.     

Sensitivity of the Optimum to Perturbations of the Profit or Weight of an Item in the Binary Knapsack Problem

In the binary single constraint Knapsack Problem, denoted KP, we are given a knapsack of fixed capacity c and a set of n items. Each item j, j = 1,...,n, has an associated size or weight w_j and a profit p_j. The goal is to determine whether or not item j, j = 1,...,n, should be included in the knapsack. The objective is to maximize the total profit without exceeding the capacity c of the knapsack. In this paper, we study the sensitivity of the optimum of the KP to perturbations of either the profit or the weight of an item. We give approximate and exact interval limits for both cases (profit and weight) and propose several polynomial time algorithms able to reach these interval limits. The performance of the proposed algorithms are evaluated on a large number of problem instances.     

Buchbesprechungen

Ohne Zusammenfassung     

Dual Career Couples als eine Variante von Work-Life-Integration

Dual Career Couples as a form of work-life-integrationThe author discusses the situation of dual career couples, when both are university graduates following an own career. Basing on a respective publication she delineates the current, mostly American research and reports on several German research projects, which endeavour to analyse the relation between gender and inequality in dual career couples.     

Von der Supervision zur Mediation und zurück

From supervision to mediation and vice versaMediation in organizations becomes more and more important because of increasing conflicts. The question is, which competencies of the counsellor are necessary, and above all, whether mediation is a particular method. The author explains the method of mediation and illustrates his concept of “patchwork-mediation”. This procedure allows to build a bridge between supervision and mediation.     

Ebert. Wolfgang (2001): Systemtheorien in der Supervision — Bestandsaufnahme und Perspektiven

Ohne Zusammenfassung