Assembly Line Balancing with Resource Dependent Task Times*

Paced assembly lines are widely used in repetitive manufacturing applications. Most previous research on the design of paced lines has assumed that each task along the line can be performed by only one worker (or a fixed number of workers). In many cases, however, task duration times may be reduced by increasing the number of workers or changing the equipment assigned to work stations. Thus, the problem becomes one of assigning resource alternatives (e.g., workers and/or equipment) and tasks to work stations to minimize total cost for a desired production rate. For this problem, we present three procedures. The first formulates the problem as a shortest path problem and guarantees optimality. The second and third are heuristic adaptations of the shortest path procedure that are capable of solving large problems. The procedures are compared in terms of solution quality and computation time on a set of 128 randomly generated problems for which optimal solutions could be found. Our simulation results indicate that the choice of procedure depends on problem complexity and resource costs.     

Patronage and secularization: social obligation and church support

As a contribution to our understanding of secularization in Britain, this paper examines the role of religious patronage. It illustrates nineteenth and early twentieth century support for the churches from rural landowners and major industrial employers, considers its benefits, and explains its rapid disappearance. The paper argues that the end of the expectation that high status individuals and major employers would actively promote organized religion is both significant evidence of secularization and a cause of further decline.     

“Shell as Hard as Steel” (Or, “Iron Cage”): What Exactly Did That Imagery Mean for Weber?

Max Weber did not invent the image of the iron cage; it was Talcott Parsons who created that image in preparing the first translation of The Protestant Ethic and the Spirit of Capitalism into English to be published. But that has not prevented it from catching on and even acquiring the status of a popular symbol of Weber's entire view of modern life. Despite its popularity, however, the image does not have a commonly accepted meaning. In part this is because of the creative uses to which it has been put by other scholars, but it is also a result of the fact that Weber himself used the German terms that were the source of Parsons’ translation in a variety of different ways over the course of his scholarly career. The purpose of this paper is to examine those uses to determine whether the meanings they convey add up to something coherent, and if so, what exactly that meaning was.     

E-leadership: Re-examining transformations in leadership source and transmission

At the turn of the century, the first integrative review and conceptualization of the work on e-leadership was published in The Leadership Quarterly. During the late 1990's, with the rapid rise in advanced information technology (AIT) such as the Internet, e-mail, video conferencing, virtual teams, and groupware systems (GDSS), there were a number of authors beginning to examine how AIT would transform how organizations organize their work and the implications for leadership in those organizations. Much of this discussion fell under the broad label of “virtual” with authors at that time speculating how such technology might impact how leadership was practiced and investigated. Now, over a decade later, we re-examine how the theory, research, and practice domains have evolved with respect to the work on e-leadership and its implications for the way leadership functions. In this review, we have broadened the notion of what constitutes e-leadership, considering how AIT affects the leadership dynamic, how the leadership dynamic affects the faithful or unfaithful appropriation of AIT, how AIT can and is being used to develop leadership, and ultimately how each will shape how organizations function well into the future. In sum, we examine what we've learned about e-leadership, what needs to be learned, and what might constitute emerging topics that could drive the e-leadership agenda over the next decade and beyond.     

The Psychological and Health Consequences of Caring for a Spouse With Dementia: A Critical Comparison of Husbands and Wives

Caring for someone with dementia can be demanding, particularly for spouses living with the care recipient. The main goal of this study was to clarify differences in the experience of caregivers who were husbands and wives with respect to burden, health, healthy behaviors, presence of difficult care recipient behaviors, social supports, and the quality of the premorbid relationship. The results of this study support research demonstrating a difference between the caregiving experiences of women and men. It is becoming increasingly apparent that female gender is a marker that places them at increased risk of high burden and less support.     

Binary Mixtures of Polycyclic Aromatic Hydrocarbons Display Nonadditive Mixture Interactions in an In Vitro Liver Cell Model

Polycyclic aromatic hydrocarbons (PAHs) have been labeled contaminants of concern due to their carcinogenic potential, insufficient toxicological data, environmental ubiquity, and inconsistencies in the composition of environmental mixtures. The Environmental Protection Agency is reevaluating current methods for assessing the toxicity of PAHs, including the assumption of toxic additivity in mixtures. This study was aimed at testing mixture interactions through in vitro cell culture experimentation, and modeling the toxicity using quantitative structure‐activity relationships (QSAR). Clone‐9 rat liver cells were used to analyze cellular proliferation, viability, and genotoxicity of 15 PAHs in single doses and binary mixtures. Tests revealed that many mixtures have nonadditive toxicity, but display varying mixture effects depending on the mixture composition. Many mixtures displayed antagonism, similar to other published studies. QSARs were then developed using the genetic function approximation algorithm to predict toxic activity both in single PAH congeners and in binary mixtures. Effective concentrations inhibiting 50% of the cell populations were modeled, with R² = 0.90, 0.99, and 0.84, respectively. The QSAR mixture algorithms were then adjusted to account for the observed mixture interactions as well as the mixture composition (ratios) to assess the feasibility of QSARs for mixtures. Based on these results, toxic addition is improbable and therefore environmental PAH mixtures are likely to see nonadditive responses when complex interactions occur between components. Furthermore, QSAR may be a useful tool to help bridge these data gaps surrounding the assessment of human health risks that are associated with PAH exposures.     

The Australian child support reforms: a critical evaluation

The Australian Child Support Scheme aims to ensure that children continue to be supported financially should their parents separate or never live together. Sweeping changes to the Australian Child Support Scheme were introduced between 2006 and 2008, featuring a dramatically different system for the calculation of child support and a more rigorous enforcement regime. The reforms were intended to respond to ongoing concerns about equity, and to changes in social expectations and practices in gender, work, and parenting. In this article we summarise key findings from a large cross‐sequential study of the child support reforms. Although the new formula initially led to lower child support payments, and an increase in the proportion of separated mothers experiencing income disadvantage, payments two years later had increased slightly. More broadly, the new scheme appears to have resulted in little change in separated parents' policy knowledge, parenting arrangements, perceptions of fairness, and child support compliance. Taken together, these findings suggest that Australia may not have made as much progress as it would have liked in this thorny area of social policy – especially in relation to compliance and perceptions of fairness.     

Chemical Scoring by a Rapid Screening of Hazard (RASH) Method

A rapid screening of hazard method (RASH) is presented for deriving relative potency estimates for hazardous substances. The method utilizes data from any available toxicological database such as the Registry of Toxic Effects of Chemical Substances (RTECS) or EPA's GENE-TOX database on genetic activity profiles. The method has been applied to derive relative potency values and permissible environmental concentrations for 278 chemicals. The derived values have been compared with recommendations of expert committees where possible, and substantial agreement is found.