Simulation investigation of the stochastic behaviour of selected group technology similarity coefficients

Abstract

Abstract. The problem of restructuring manufacturing facilities into a cellular format has been addressed using a variety of approaches, including block-diagonalization of the machine-component matrix, mathematical programming formulations and cluster analyses. This paper addresses the problem of assessing whether or not the machine-component mix of a particular facility is amenable to cellular restructuring. The focus is cluster analytic; specifically a number of recently developed similarity coefficients are applied to problems generated via Monte Carlo simulation. The results show that, in a number of cases, the quality of the original block diagonal structure had a significant effect on the shape (in particular, skewncss and kurtosis) of the distribution of similarity coefficient values.     

CRIME AND PUNISHMENT IN MAJOR LEAGUE BASEBALL: THE CASE OF THE DESIGNATED HITTER AND HIT BATTERS

Past studies have found a positive correlation between the use of the designated hitter in baseball and hit batters, but the reason for this is debatable. Using a new micro‐level data set of individual plate appearances, we control for detailed cost‐benefit attributes that affect the decision calculus of the pitcher to isolate the deterrent impact of requiring the pitcher to bat. We find that pitchers hit batters strategically, and the deterrent effect of requiring pitchers to bat explains 60%–80% of the difference in hit batsmen between leagues. We also identify evidence of direct retaliation against plunking pitchers. (JEL D81, KC42, L83)     

DRAWN INTO VIOLENCE: EVIDENCE ON “WHAT MAKES A CRIMINAL” FROM THE VIETNAM DRAFT LOTTERIES

Draft lottery number assignment during the Vietnam Era provides a natural experiment to examine the effects of military service on crime. Using exact dates of birth for inmates in state and federal prisons in 1979, 1986, and 1991, we find that draft eligibility increases incarceration for violent crimes but decreases incarceration for nonviolent crimes among whites. This is particularly evident in 1979, where two‐sample instrumental variable estimates indicate that military service increases the probability of incarceration for a violent crime by 0.34 percentage points and decreases the probability of incarceration for a nonviolent crime by 0.30 percentage points. We conduct two falsification tests, one that applies each of the three binding lotteries to unaffected cohorts and another that considers the effects of lotteries that were not used to draft servicemen. (JEL K42, H56)     

AN EVALUATION OF ORDER PICKING POLICIES FOR MAIL ORDER COMPANIES

This paper is concerned with the problem of order picking in mail order companies. Order picking is the retrieval of items from their warehouse storage locations to satisfy customer orders. Five order picking policies, strict order, batch, sequential zone, batch zone, and wave, are evaluated using labor requirements, processing time, and customer service as performance measures. A simulation model was developed to investigate these picking policies in a mail order environment. Prior research has focused on the study of individual picking policies. This study extends the prior research by evaluating multiple picking policies under varying operating conditions. The results of the study seem to indicate that (1) wave picking and batch picking perform well across the range of operating conditions considered in this study, and (2) sequential zone and batch zone picking do not perform well, especially as the order volume increases. However, the benefits and drawbacks to each picking policy must be taken into account. The key to effective implementation of an order picking system is to match the firm's business strategy, capabilities, technology, and space requirements with an order picking policy that maximizes the benefits of order picking to the firm and its customers.     

SUICIDE AS AN INDEX OF ROLE STRAIN AMONG EMPLOYED AND NOT EMPLOYED MARRIED WOMEN IN BRITISH COLUMBIA*

Une comparaison est effectuée entre les taux de suicide chez les femmes mariés qui travaillent et chez celles qui ne travaillent pas afin de tester 1'idée que les coûts de travailler, à savoir, les conflits de rôle et la surcharge, sont plus importants que les a vantages économiques et ceux provenants des liens sociaux. L'analyse des taux de suicide en CB en 1961 et 1971 suggère cependant que les bénéfices dépassent les coûts. L'examen des taux de suicide chez les femmes de d'autres états maritaux suggère que 1'avantage principal de travailler est social plutôt qu'économique. D'autres explications des résultats sont discutées. Suicide rates of married women who work are compared with the rates of those who do not in order to test the proposition that the costs of working, that is, role conflict and role overload, outweigh the economic and affiliative benefits. Analysis of suicide rates in BC in 1961 and 1971 suggests, however, that the benefits of working outweigh the costs. Consideration of the rates of suicide among women of other marital statuses suggests that the main benefit of working may be affiliative rather than economic. Alternative explanations of the findings are discussed.     

THE IMPACT OF TELEVISION VIEWING ON MENTAL APTITUDE AND ACHIEVEMENT: A LONGITUDINAL STUDY

Previous studies of the effects of telecision viewing on mentalabilities have shown mixed results, but most suffered from oneor more of the following shortcomings: a small or other-wiseunrepresentative sample, a cross-sectional rather than longitudinalapproach, and a failure to consider intervening variables betweentelevision viewing and cognitive skills. This study was designedto overcome these deficiencies by using nationally representativedata from the National Health Examination Cycle 2 and Cycle3 Surveys. These surveys included 1,745 children who were studiesboth when 6 to 11 years old (between July, 1963, and December,1965) and about four years later when 12 to 17 years old (betweenMarch, 1966, and March, 1970). Simple analysis at just one time-pointreveals substantial relationships between the amount of televisionviewing and depressed IQ and Wide Range Achievement Test (Readingand Arithmetic) scores of adolescents. When longitudinal controlsare added, however, these relationships become statisticallyinsignificant and substantively unimportant. Although thesedata are 20 years old, they indicate no significant causal relationshipbetween the amount of television viewed and the mental aptitudeand achievement test scores of adolescents, thus supportingand extending Gaddy's (1986) recent longitudinal study of anational sample of youth.     

Understanding and Preventing Burn-Out

Please address reprint requests to Professor C. Zastrow, Department of Social Welfare, University of Wisconsin-Whitewater, 800 West Main Street, Whitewater, WI 53190, USA. Summary This article defines burn-out and describes its symptoms andcauses. Burn-out is conceptualized as being one of the reactionsto high levels of stress. Strategies to prevent and treat burn-outare presented.     

THE MAN IN THE TEFLON SUIT?: THE ENVIRONMENTAL CONNECTION, POLITICAL DRAMA, AND POPULAR SUPPORT IN THE REAGAN PRESIDENCY

An examination of public support during the presidency of RonaldReagan reveals a unique pattern. The major features includetwo instances of rapidly declining support followed by historicallyunprecedented and sustained recoveries. The recovery of supportis particularly surprising given that the literature of theearly 1980s emphasizes the irrecoverable erosion of public supportand a resulting "no win" presidency. In this sense, the patternof public support from 1981 to 1987 raises a significant questionabout the "no win" presidency. Does the Reagan case contradictrecent assertions about the inability of modern presidents tomaintain public support or is Reagan an exception that "provesthe rule"? To answer this question, the analysis is divided into five parts.The first examines the literature and shows that there is astriking uniformity in contemporary accounts of Reagan's publicsupport. These explanations discount the importance of conditionsin the environment and emphasize that Reagan's public supportis based upon a mixture of luck, personality, and politicaldrama. Part two defines political drama and examines its usefrom 1981 to 1987. In part three, we develop a methodology forincorporating political drama into a general model of publicsupport for Reagan. Part four estimates the model and uses theresults to assess the relative impact of the economy and politicaldrama on public support for Reagan. These results are used inthe final section to evaluate the specific explanations of Reagan'spublic support and to reflect upon the competing general explanationsfound in the literature.