A hybrid genetic algorithm for the batch sequencing problem on identical parallel machines

The batch sequencing problem (BSP) has been the focus of much research thanks to its practical applicability and NP-hard nature. This study aims to solve an extension of the problem from single machine case to parallel machine case. A dispatching rule called the EDD (Earliest Due Date)-Greedy heuristic and a pure genetic algorithm (GA) are proposed, and then combine them through an insertion method called the Gene Bank Strategy. Several test cases of up to 12 machines and 60 jobs are randomly generated and solved. Those experiments show that the introduced hybrid GA can provide far better results than its two component algorithms that can also independently solve the problem.     

Three Journeys Toward The Reflecting Team

The experience of familiestrainee and supervisory therapists involved in reflecting team work are explored through the metaphor of ‘journey’ and by asking a small number of our colleagues and clients about their experiences. Ideas gained from this approach are tentatively used to raise some questions about the reflecting team specifically and the current direction of family therapy. More rigorous research into this area is invited.     

Nonprofit management in Europe and Asia

The State and NGOs: Perspective from Asia, edited by Shinichi Shigetomi. Singapore: Institute of Southeast Asia Studies, 2002. $28.50 cloth. The Emergence of Social Enterprise, edited by Carlo Borzaga and Jacques Defourny. New York: Routledge, 2001. $120.00 cloth.     

Cross-Cultural Supervision

A multicultural perspective is essential in the twenty-first century. It is projected that by the year 2010 twelve of our most populous states will have significant minority populations. Thus, the supervision triad of patient, psychoanalyst, and supervisor will most likely contain persons of differing racial-ethnic backgrounds who are confronting problems and concerns in a diverse social environment. This paper uses examples to illustrate how this diverse triad is played out.     

Momentum and the growth-free segment of a population

In the scenario of a sudden drop in fertility to replacement level. Preston (1986) argued that the population segment under age T, the length of generation, remained growth-free. Here we first present a new relationship for the momentum of any observed population as the ratio of 1) the proportion of the observed population under the mean age at childbearing to 2) the proportion of its life table population under that mean age. We then use that relationship to demonstrate Preston's approximation. Growth factors for other population segments are also presented. When the initial population is stable, momentum can be approximated as a function of the net reproduction rate alone.     

Structure and accountability a study of national nonprofit associations

In the 1990s, the integrity and performance of nonprofit organizations in the United States have come increasingly under attack, and there are new calls to hold nonprofit organizations more accountable for their behavior and performance. This article reports on a study of the organizational structures of national nonprofit associations and asks how these umbrella organizations can help to self-regulate the sector through appropriate checks and balances between the national organization and local affiliates. The authors identify a number of differences in how associations with alternative structures hold local affiliates and national organizations responsible for their performances, and they conclude that structure is an avenue of self-regulation for nonprofit organizations deserving further attention.