等截面斜腿刚构桥的几何布局优化

以应力平方均值最小为优化目标，建立了跨越V形谷的等截面斜腿刚构桥在列车荷载和自重共同作用下的布局静力优化的数学模型，采用直接搜索法进行了设计变量的寻优。     

差异化人才管理对员工创新绩效的“双刃剑”效应

基于调节焦点理论和公平启发理论,运用结构方程模型考量差异化人才管理对员工创新绩效的影响机制。结果显示：促进定向工作重塑在差异化人才管理与员工创新绩效之间起正向中介作用,防御定向工作重塑在二者间起负向中介作用;组织公平感正向调节差异化人才管理与促进定向工作重塑之间的关系,负向调节差异化人才管理与防御定向工作重塑之间的关系;组织公平感增强促进定向工作重塑的正向中介作用,削弱防御定向工作重塑的负向中介作用。     

The evolution of consumer knowledge and sources of information: Hungary in transition

The authors’ research in Hungary during the period of transition to a market economy provides an opportunity to examine the evolving relationships between consumer product knowledge and its antecedents, including advertising, personal search, interpersonal sources, and brand experience. Their findings, based on survey data collected in Budapest in 1992 and 1998, indicate that the market information variables explain more variance in consumer knowledge later rather than earlier in the transition. Advertising is an important predictor of consumer knowledge later but not earlier in the transition, personal search is important at both times, and interpersonal sources are not important in either time period; brand experience is negatively related to knowledge earlier in the transition and positively related later in the transition. This study allows one to begin to understand the boundary conditions associated with studies conducted in developed economies. Managerial implications for firms investing in transitional economies are presented. Robin A. Coulter (robin.coulter@business.uconn.edu) is Ackerman Scholar and an associate professor of marketing in the School of Business at the University of Connecticut. She received her Ph.D. from the University of Pittsburgh. Her research interests include branding, cross-cultural consumer behavior, advertising, and research methods. Her work has appeared in theJournal of Consumer Research, the Journal of Consumer Psychology, theJournal of Applied Psychology, and theInternational Journal of Research in Marketing. Linda L. Price (llprice@email.arizona.edu) is Soldwedel Professor of Marketing in the Eller School of Management at the University of Arizona. She received her Ph.D. from the University of Texas at Austin. Her research combines qualitative and quantitative methodologies to examine the active, emotional, imaginative aspects of consumers’ decisions and activities, and the social and cultural context of marketplace behaviors. Her work has appeared in theJournal of Consumer Research, Journal of Marketing, and other leading marketing, management, and social science journals. Lawrence Feick (feick@katz.pitt.edu) is a professor of business administration in the Katz Graduate School of Business at the University of Pittsburgh. He received his Ph.D. from Pennsylvania State University. His current research focuses on cross-cultural consumer behavior, consumer word-of-mouth, and referrals. His work has appeared in the Journal of Marketing, theJournal of Marketing Research, the Journal of Consumer Research, Psychological Bulletin, andPublic Opinion Quarterly. Camelia Micu (camelia.micu@business.uconn.edu) is a marketing doctoral candidate at the University of Connecticut. Her research interests include advertising and product trial and cross-cultural consumer behavior.     

Physical Search

Unidirectional search is an evolutionarily stable outcome in an economy where homogenous buyers and sellers can either move or stay. It is more efficient than bidirectional search. In unidirectional search, it is more efficient if the more numerous agents move and the less numerous agents stay, than vice versa.     

Youth labor market expectations and job matching in sub-Saharan Africa: evidence from school-to-work transition surveys

In this paper, we investigate the factors that influence youth labour market expectations and outcomes. We also perform a job matching exercise to understand youth labour market dynamics in Sub-Saharan Africa. Our results show that youth education is an influential factor of youth employment expectations and employment, ceteris paribus. Higher educational attainments have a great impact on expecting and securing better jobs, particularly in the technical and professional fields. Youth with low educational attainments, particularly primary education and lower, have a higher tendency to expect to be employed in occupations with low job complexity. Our results indicate a severe job-skill mismatch in all occupational categories, both before and after the youth’s transition into the labour market. Using education as the only selection criterion, we found that less than 10 per cent of employment expectations match with skills required while 55 per cent and 34 per cent are under or over-educated for the jobs expected, respectively. Over and under education is a notable feature in youth labour markets in Sub-Saharan Africa. About 47 per cent of employed youth in the sample are overqualified for their respective jobs while 28 per cent are under qualified.     

Overeducation, regional labor markets, and spatial flexibility

For most workers, access to suitable employment is severely restricted by the fact that they look for jobs in the regional labor market rather than the global one. In this paper we analyze how macrolevel opportunities (regional market characteristics) and microlevel restrictions (the extent to which job searchers are restricted to the regional market) can help to explain the phenomenon of overeducation. We use a two-step procedure to control selective access to employment. The results show that the size of the labor market is an important factor in avoiding overeducation.     

Job Creation and Job Destruction in a Regulated Labor Market: The Case of Austria

We study Austrian job reallocation in the period of 1978 to 1998, using a large administrative dataset where we correct for spurious entries and exits of firms. We find that on average 9 out of 100 randomly selected jobs were created within the last year, and that about 9 out of randomly selected 100 jobs were destroyed within the next year. Hence, the magnitude of Austrian job flows seems to be comparable to other countries, similar to the well-known results of Davis et al. (1996) for the United States. Job reallocation appears to be driven primarily by idiosyncratic shocks. However, job creation increases significantly during cyclical upswings whereas job destruction rises in downturns. We also find substantial persistence of job creation and destruction. The pronounced pattern of job reallocation rates falling with firm size and age continues to hold when we use a set of controls. Finally, we show that – controlling for sector and firm size composition – Austrian job reallocation rates are only half the rates for the U.S. This result is not surprising given the impact of tighter regulation and labor law in Austria.     

Good News and Bad News: Search from Unknown Wage Offer Distributions

The largest market in national economies is the labor market. Labor market contracting is characterized by job search, often from unknown wage offer distributions. This paper reports experimental tests of finite horizon models of job search in which the wage offer distribution is unknown. Theoretically-optimal search from an unknown wage offer distribution can have the seemingly paradoxical property that some offers will be accepted that are lower than other offers that will be rejected in the same period of the search horizon. Thus the reservation wage property (or lowest acceptable wage path) may not exist. This can occur because an offer that is a priori relatively high (good news) can imply that it is highly probable that search is from a favorable distribution, and such an offer can look unattractive when it is an a posteriori relatively low offer from a favorable distribution (bad news). This paper reports results from experimental treatments for search from unknown distributions in which the reservation wage property does exist and treatments in which it does not exist. We find that the consistency of search behavior with search theory reported in earlier papers is robust to the presence or absence of the reservation wage property and to whether the draws come from known or unknown distributions.     

企业应用集成在物流信息化中的应用

企业间的竞争已经延伸到了物流领域，在这种环境下，进行物流信息化，实现无障碍地访问物流信息的重要性日益突出。本文介绍了企业应用集成（EAI）的基本概念以及在物流信息化中的作用，最后还说明了EAI在物流信息系统集成中的发展趋势。     

一种基于遗传算法求解车间调度问题的优化方法

遗传算法是解决车间调度问题的有效方法之一。但在构造适应度函数时由于调度问题诸多的束条件使得直接求解十分困难。罚函数法将约束条件加到目标函数上，变有约束为无约束．能较易求解该类问题。