A genetic algorithm for determining optimal replenishment cycles to minimize maximum warehouse space requirements

In a supply chain, it is an important issue for logistic managers to offset the replenishment cycles of multiple products sharing a warehouse so as to minimize the maximum warehouse space requirement (MWSR). Most of the studies in the literature assume that warehouses replenish at the beginning of some basic planning period. In this paper, we relax this assumption by allowing the warehouse to replenish at any time. In order to solve this problem, we conduct theoretical analysis based on Fourier series and Fourier transforms and propose a procedure that is used to calculate MWSR efficiently for any given replenishment schedule. Then, we employ this procedure in a genetic algorithm (GA) to search for the optimal replenishment schedule. Using randomly generated instances, we show that the proposed GA significantly outperforms a previously published heuristic.     

人·风格·价值--评李夫泽先生的谢冰莹研究

纵观夫泽先生的谢冰莹研究,在搜集占有大量资料的基础上,尽其最大努力地使作家谢冰莹的人格与心路历程、作品的风格与价值全方位地从现当代文学史中凸现出来,从而为20世纪中国文学史的重新发掘与定位提供学术支持.     

张謇与近代海洋渔业

张謇为我国渔业及发展海洋事业、培养国民重视海洋的意识作出了重大贡献.现在,世界各国都十分重视海洋权利,从开发海洋资源,以海洋经济作为今后我国国民经济发展的一个重要方面的趋势来看,张謇和海洋渔业的关系研究仍可以为我们提供宝贵的借鉴.     

一维无限深势阱中粒子动量测量问题的分析与讨论

对在一维无限深势阱中运动的粒子的动量测量问题进行了全面的分析和仔细的讨论,补充了量子力学教材中对这个问题的处理.     

The Effect of Veteran Status on Mortality among Older Americans and its Pathways

This research examines excess mortality among American veterans age 70 years or older during a two-to-three year interval from 1993/94 to the end of 1995. Using a structural hazard rate model, we analyzed data on a sample of respondents age 70 or over from the Survey of Asset and Health Dynamics among the Oldest Old (AHEAD). We found that at age 70, older veterans have a slightly higher death rate than their nonveteran counterparts, implying a mortality crossover right before this age. Such excess mortality among veterans increases considerably with age, when other factors are held equal. The direct and indirect effects of veteran status on mortality by means of physical and mental health mostly perform in opposite directions, and such effects vary greatly in magnitude and direction as a function of age. The intervening effects of physical and mental health status decrease substantially with increasing age. Many of the mechanisms inherent in the excess mortality among older veterans are not captured by variations in their health status, especially among the oldest-old. A more extensive study on this topic is urgently needed.     

Energy supply shocks: Macroeconomic consequences for Ukraine

In exploring the short-term macroeconomic effects of energy supply shocks in Ukraine, this paper relies on the simplifying assumption that enterprises face economic regulation but not ownership uncertainty or a soft budget constraint that would adversely affect their behavior. In a sense, it assumes that Ukraine's economy is already at the second stage of reform, when ownership, contract-enforcement, and hard budget constraint questions are less of an issue. Under these assumptions and if real wages are protected, the analysis yields clear messages. Protecting the domestic economy by not passing through external price increases may cushion the decline in production and social welfare, but at a heavy cost to savings and investment; not only does it postpone adjustment and the emergence of a competitive economy, but it also deprives the economy of investible resources. Passing through external price increases while maintaining a fixed-price regime may improve the mobilization of resources but at a heavy cost to output and welfare, because it induces a heavy contraction in activity. Liberalizing prices in the nonenergy sectors in conjunction with passing through external price increases allows these sectors to generate the larger resource transfers required by a deteriorating terms of trade, in turn pulling up output; the economy can settle at a higher level of activity and welfare than in the presence of fixed prices. The conclusion is that Ukraine must clarify ownership and contract-enforcement issues as well as harden the budget constraints of enterprises as rapidly as possible, liberalize nonenergy prices at a minimum, and begin adjusting domestic energy prices to reflect the opportunity cost of these resources. Since the fall of 1994, Ukraine has proceeded to liberalize its price and trade regime, which should bring the economy a long way to recovery as outlined in this paper.     

城乡一体化的农村污染防治制度研究——以辽宁省为例

城乡一体化是我国新农村建设的必然趋势,它在带动我国农村经济发展的同时,对我国农村环境污染防治提出了新的挑战。以辽宁省为例,农村生活垃圾污染、农村生活污水污染、农业种植污染及畜禽养殖污染等污染问题已经十分严峻,亟待有效解决。影响农村污染防治的因素有多种,其中"二元"社会结构是影响农村污染防治的最深层原因,农村污染防治法律体系缺失及监管体制欠缺是影响农村污染防治的法制原因。因此,应当以城乡一体化发展趋势作为我国农村污染防治的基础,完善农村环境保护立法,加强农村污染监管,并可尝试利用补贴激励等制度缓解和减少我国农村环境污染。     

高校“会计电算化”课程教学问题探讨

针对目前我国高校会计电算化课程的教学现状,本文从课程设置、师资培训、教学方式等几个方面,阐述了存在的主要问题及解决对策。     

美国“无辜物主抗辩”近观

美国的"无辜物主抗辩"经历了从无到有,从弱到强的发展历程。在漫长的形成与发展过程中,美国法律逐渐探索出根植于美国法治土壤的独特的第三人财产保护制度。现行的"无辜物主抗辩"也为美国民事没收制度带来了新的发展力量。从历史发展的角度了解美国"无辜物主抗辩"的由来,并深入分析《美国法典》现行的"无辜物主抗辩"的相关概念及其适用,既是对美国民事没收程序的深入了解,更是中国今后在第三人财产保护制度上可以借鉴与参考的理论基础。     

高校推行战略导向的全面预算管理体系初探——以YL大学为例

当前,＂收支平衡观＂主导着高校的预算管理模式,而这一模式却存在目标不明确、编制不科学、执行不力、评价体系不健全、机构设置不合理等诸多问题。通过对Y L大学预算管理现状的分析,从高校发展战略出发,提出一种融合学校发展目标、资源配置、业绩评价、激励约束四位一体的现代预算管理体制构想,合理分配人力、物力、财力等资源于教学、管理、科研各个环节,以期使预算执行与战略规划有机结合,从而提高资金使用效率。