Optimal operating policies in a commodity trading market with the manufacturer's presence

With the help of the Internet and express delivery at relatively low costs, trading markets have become increasingly popular as a venue to sell excess inventory and a source to obtain products at lower prices. In this article, we study the operational decisions in the presence of a trading market in a periodic‐review, finite‐horizon setting. Prices in the trading market change periodically and are determined endogenously by the demand and supply in the market. We characterize the retailers'optimal ordering and trading policies when the original manufacturer and the trading market co‐exist and retailers face fees to participate in the trading market. Comparing with the case with no trading fees, we obtain insights into the impact of trading fees and the fee structure on the retailers and the manufacturer. Further, we find that by continually staying in the market, the manufacturer may use her pricing strategies to counter‐balance the negative impact of the trading market on her profit. Finally, we extend the model to the case when retailers dynamically update their demand distribution based on demand observations in previous periods. A numerical study provides additional insights into the impact of demand updating in a trading market with the manufacturer's competition. © 2009 Wiley Periodicals, Inc. Naval Research Logistics, 2010     

高校现代教育技术应用现状及发展趋势

通过对高校现代教育技术应用现状的分析,阐述了高校现代教育技术应用的发展趋势。     

应用Isight的复合材料桁架结构优化设计

轻质复合材料及其结构以其优异的力学性能在航天航空飞行器上得到了广泛应用。考察玻璃纤维/环氧复合材料方形截面桁架在典型弯曲载荷工况条件下的非线性结构承载性能。采用Isight集成平台对桁架结构进行多参数优化设计,获得满足结构刚度和承载性能要求的最轻质桁架结构的几何参数,并分析最优化结构在载荷作用下的结构非线性响应行为。结果表明采用Isight平台对桁架结构进行多参数优化设计具有较高的效率和可信度。     

Estimating failure time distribution and its parameters based on intermediate data from a Wiener degradation model

Instead of measuring a Wiener degradation or performance process at predetermined time points to track degradation or performance of a product for estimating its lifetime, we propose to obtain the first‐passage times of the process over certain nonfailure thresholds. Based on only these intermediate data, we obtain the uniformly minimum variance unbiased estimator and uniformly most accurate confidence interval for the mean lifetime. For estimating the lifetime distribution function, we propose a modified maximum likelihood estimator and a new estimator and prove that, by increasing the sample size of the intermediate data, these estimators and the above‐mentioned estimator of the mean lifetime can achieve the same levels of accuracy as the estimators assuming one has failure times. Thus, our method of using only intermediate data is useful for highly reliable products when their failure times are difficult to obtain. Furthermore, we show that the proposed new estimator of the lifetime distribution function is more accurate than the standard and modified maximum likelihood estimators. We also obtain approximate confidence intervals for the lifetime distribution function and its percentiles. Finally, we use light‐emitting diodes as an example to illustrate our method and demonstrate how to validate the Wiener assumption during the testing. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008     

战场空间本体构建方法研究

从构建战场空间知识基础设施,进而形成一体化的知识处理平台、获取知识优势出发,将本体思想引入战场空间知识建模领域,提出了战场空间本体体系,即战场空间本体包括上层本体、领域本体、应用本体;并重点研究了一种战场空间领域本体的构建方法BOC,包括基于上层本体BUO的领域本体构建方法,基于上层本体BUO的领域本体合并方法.基于本体的战场空间知识建模从根本上解决了战场空间中知识系统之间的知识共享和重用问题,便于知识系统的集成.     

TVM制导防空导弹先验距离战法

为了对空袭体系中施放电子干扰的目标进行打击,根据TVM制导防空导弹的技术特点,采用先验距离法,通过制导雷达和导弹组网,进行无源测向交会定位,能够较准确地得到目标定位并对导弹进行精确制导.给出了先验距离方法的数学模型和数据融合方法,最后提出了先验距离战法实施的基本原则.     

罗炳辉与军事统一战线

作为中国人民解放军36位军事家之一的罗炳辉,被赞颂为传奇式英雄、智勇双全的人物①.罗炳辉的传奇军旅生涯不仅表现在,他指挥军队在与敌军兵戎相见的战场上.     

武器系统作战模拟环境的设计与实现

针对当前武器系统作战模拟不易于使用的观状,探讨了建立武器系统作战模拟多媒体表现环境的概念、方法和必要性,从总体上研究了武器系统作战模拟多媒体表观环境的系统结构、功能要求和实现过程。     

基于约束的交互式电气线路故障诊断

给出了器件的约束表示,实现了电气线路的约束网络化.分析了电气线路约束网络的特点,找出了故障树的剪节方法,提出了基于约束故障诊断的方法和步骤.     

培养学生英语写作能力初探

写作是一种交际能力,提高写作能力必须具有较好的语言基础．论述了抓好英语精读课教学是提高学生写作能力的关键,写作能力的提高离不开“步步高”的训练方法,即：从学写单句到学写文章的分步训练步骤．