Optimal capacity in a coordinated supply chain

We consider a supply chain in which a retailer faces a stochastic demand, incurs backorder and inventory holding costs and uses a periodic review system to place orders from a manufacturer. The manufacturer must fill the entire order. The manufacturer incurs costs of overtime and undertime if the order deviates from the planned production capacity. We determine the optimal capacity for the manufacturer in case there is no coordination with the retailer as well as in case there is full coordination with the retailer. When there is no coordination the optimal capacity for the manufacturer is found by solving a newsvendor problem. When there is coordination, we present a dynamic programming formulation and establish that the optimal ordering policy for the retailer is characterized by two parameters. The optimal coordinated capacity for the manufacturer can then be obtained by solving a nonlinear programming problem. We present an efficient exact algorithm and a heuristic algorithm for computing the manufacturer's capacity. We discuss the impact of coordination on the supply chain cost as well as on the manufacturer's capacity. We also identify the situations in which coordination is most beneficial. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008     

Optimal timing of switches between product sales for sports and entertainment tickets

Like airlines and hotels, sports teams and entertainment venues can benefit from revenue management efforts for their ticket sales. Teams and entertainment venues usually offer bundles of tickets early in their selling horizon and put single‐event tickets on sale at a later date; these organizations must determine the best time to offer individual tickets because both types of ticket sales consume the same fixed inventory. We model the optimal a priori timing decision for a seller with a fixed number of identical tickets to switch from selling the tickets as fixed bundles to individual tickets to maximize the revenue realized before the start of the performance season. We assume that bundle and single‐ticket customers each arrive according to independent, nonhomogeneous Markovian death processes with a linear death rate that can vary over time and that the benefit from selling a ticket in a package is higher than from selling the ticket individually. We characterize the circumstances in which it is optimal for the seller to practice mixed bundling and when the seller should only sell bundles or individual tickets, and we establish comparative statics for the optimal timing decision for the special case of constant customer arrival rates. We extend our analytical results to find the optimal time for offering two groups of tickets with high and low demand. Finally, we apply the timing model to a data set obtained from the sports industry. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2008     

ATIE:一种自适应的可调域间出口选择算法

TIE算法能对域间出口的选择进行调节,但是该算法的参数计算过于复杂,并且出口选择的调节并不能随负载的变化而变化,因此提出了一种自适应的可调域间出口选择算法ATIE,该算法能够满足流量工程和网络健壮性要求,并通过参数T的改变随当前负载的变化而变化.实验表明,ATIE算法能够在控制剖面敏感性和随负载变化的流量工程自适应性上达到合理的折衷.     

普通高校非英语专业新生英语学习观念和策略的研究

本文以问卷和面谈的形式对非英语专业大学一年级新生作了一次调查,通过定量和定性分析发现:(1)学生对外语学习中的个体差异,外语学习的内容和形式,母语在外语学习中的作用没有明确的看法;(2)学生普遍认同管理学习过程的重要性;(3)学生的学习观念和学习策略之间存在着很大的差距。并探讨了此调查结果对外语策略培训的启示。     

关于平安校园建设的几点思考

平安校园建设是构建和谐校园的重要举措,是实现高校自身发展的内在要求。文章从认识建设平安校园的重要意义着手,分析了当前高校平安建设中的问题,提出了相应的对策。     

DEA方法在防空作战方案优选中的应用

针对现代防空作战对决策速度和准确性的要求,运用DEA方法研究了防空作战方案优选问题。根据防空作战方案构成的主要要素,建立了防空作战方案的C2R评估模型,从“技术有效”和“规模有效”两个方面对备选方案的有效性进行综合分析,得出各方案评估结果,为指挥员优选方案提供了科学准确的依据。与传统的方法相比,该方法不仅具有内在的客观性,避免了方案中投入和产出指标间的相互制约,而且易于实现计算机处理,有效保障指挥员在防空作战中快速准确选定作战方案。     

大学生心理危机干预及其对策研究

个别大学生的非正常死亡,给高校心理危机干预提出了现实要求。无论从保护学生健康成长的层面,还是从为国家培养合格接班人的角度,各高校都应该高度重视大学生心理危机干预工作,建立完善的机构,配备专职的心理危机干预人员,加强大学生在校期间的心理健康教育。     

中哈石油合作的安全战略及国家利益

经济快速增长时期旺盛的石油需求使中国石油进口及对外依存度不断上升,石油来源及进口安全成为保障经济安全的战略难题;中哈两国凭借资源、地缘优势和共同的利益需要,业已建立起牢固的互信关系和利益纽带,以中哈输油管道对接为契机的石油合作为我国石油安全战略和国家利益的实现提供了历史机遇,不但使我国石油来源及进口多元化有了坚实的基础和可靠的保证,从而掌握石油贸易全球化的主动权,而且可加快我国石油资源利用的市场化、国际化进程,为我国顺利完成工业化进程提供多元化的能源保障。     

机场道面抢修应急起降带的确定

应急起降带的确定是战时机场道面抢修的基础性工作,对抢修工程量、抢修效率、抢修进程都有着重大影响.首先介绍了应急起降带合理尺寸的确定;然后提出了应急起降带最佳抢修位置的确定原则;为了实现应急起降带方案的快速优选,用VB编写了方案优选程序,改变了传统的人工优选法费时费力的现状.从文中的实例分析可以得出结论:该方案优选程序的运算结果满足实际抢修施工需要.     

循环经济与可持续发展

循环经济和知识经济并称为21世纪发展新亮点,也是世纪之交人类社会可持续发展的两大趋势。人类社会在经历了漫长的发展历史之后,正处于一种大量的资源、能量的耗费,大量的废物进入生存环境的状态,自然环境一次又一次向人类敲响警钟。本文试从循环经济这一视角来对其与可持续发展的问题进行探讨。