Oligopolistic contracting: Channel coordination under competition

We study contracts between a single retailer and multiple suppliers of two substitutable products, where suppliers have fixed capacities and present the retailer cost contracts for their supplies. After observing the contracts, the retailer decides how much capacity to purchase from each supplier, to maximize profits from the purchased capacity from the suppliers plus his possessed inventory (endowment). This is modeled as a noncooperative, nonzero‐sum game, where suppliers, or principals, move simultaneously as leaders and the retailer, the common agent, is the sole follower. We are interested in the form of the contracts in equilibrium, their effect on the total supply chain profit, and how the profit is split between the suppliers and the retailer. Under mild assumptions, we characterize the set of all equilibrium contracts and discuss all‐unit and marginal‐unit quantity discounts as special cases. We also show that the supply chain is coordinated in equilibrium with a unique profit split between the retailer and the suppliers. Each supplier's profit is equal to the marginal contribution of her capacity to supply chain profits in equilibrium. The retailer's profit is equal to the total revenue collected from the market minus the payments to the suppliers and the associated sales costs.     

弹道导弹威胁估计模型构建

简要分析了弹道导弹飞行3个阶段的不同特点及各阶段导弹预警探测手段的侧重点,结合威胁估计的特征构建了弹道导弹威胁估计模型结构框架,运用多阶段贝叶斯网络理论,构造了主动段、自由段和再入段威胁估计模型,并明确了三阶段间的转换时机。采用动态贝叶斯方法对弹道导弹作战全过程进行威胁估计仿真推理,仿真结果能够反映导弹在飞行过程中威胁程度的变化特点,为反导指挥员作出辅助决策提供智力支持。     

目标识别中的传感器管理方法

基于假设检验的方法,研究了目标识别中的传感器管理方法。分别以用于假设检验问题中的最大后验概率、最小代价函数和最大正确检测概率为目标函数,给出了用于目标识别问题的多传感器管理方法,并针对目标识别问题的特点,对其进行了相应的改进。通过对一定场景的仿真,比较了三种不同方法的识别正确率和平均采样次数,分析了各种方法的特点。     

The economic effects of international trade in armaments in the major western industrialized and developing countries†

We have used the Michigan Model of World Production and Trade to assess the impact of exports and imports of armaments (based on 1980 data) on sectoral trade and employment and other economic variables in the major Western trading countries. If the United States were to place a unilateral embargo on its arms exports and imports, we calculate that it would experience a comparatively small amount of employment displacement in the aggregate and that most of this displacement would occur in the transport equipment and electric machinery sectors. If all the major Western countries were to place a multilateral embargo on their arms trade, the sectoral effects on the United States would be similarly small. But the sectoral effects in several other industrialized and developing countries measured as a percentage of sectoral employment, would be larger, indicating potential short‐run adjustment problems in labor markets in some cases.     

发动机冷却燃料做功潜力?分析

在高马赫数飞行下,用燃料冷却超燃冲压发动机壁面的冷却需求量大于发动机燃烧量。为了降低燃料的冷却量以及实现燃料冷却量和燃烧量的匹配,采用?分析法对超燃冲压发动机壁面燃料冷却工质进行做功潜力分析。发动机壁面冷却燃料的特性决定其热量?大小。根据发动机壁面温度分布、热流密度分布计算热量?,建立稳定流动燃料工质的?平衡方程。结果表明：在壁面最高温度为1200K时,传入壁面的热量为562.4kW,其中理论热量?为541.3kW;冷却燃料工质流量的增加,最大输出功减小;燃料工质出口温度增加,输出功减小,燃料工质出口压力增加,输出功基本不变。     

基于贝叶斯网络的空中目标威胁估计方法研究

针对当前威胁估计中存在的问题,提出了基于贝叶斯网络的空中目标威胁估计方法。文章从威胁估计的概念出发,构建了基于贝叶斯网络的威胁估计功能框架,在对输入的防空作战事件进行分类定义的基础上,给出了事件关联在贝叶斯网络中的实现方法,同时对模型的建立步骤进行了说明。文中提出的威胁估计方法在融合了目标威胁先验信息的基础上,通过战场观测到的不确定信息进行推理,其结果具有很强的可信性,相应的建模思路可为威胁估计系统的构建提供有益的参考。文章的最后以一个示例说明了方法的有效性。     

基于敏感性分析的DF化学动力学模型的简化

基于两种燃料体系下的DF详细化学反应动力学模型,利用敏感性分析的方法,分别提出了相应的简化反应机理.简化过程中发现,仅考虑DF“冷反应”泵浦过程,忽略掉高振动激发态,忽略掉D2和DF分子的离解复合反应对整个系统影响不大.DF分子之间以及DF与D、D2、HF之间的能量转移反应具有较高的敏感性.简化机理在有效概括DF化学反...     

高超音速化学平衡流粘性激波层数值计算

本文给出了层流化学平衡粘性激波层方程对于细长解析体的数值解。这些求解结果是通过空间步进方法得到的,并且与参考文献里的计算结果作了比较,以估价该方法的精确度。结果表明,这种控制方程完全耦合求解的方法能够给出相当精确和稳定的结果,这些结果与参考文献的计算结果相当吻合。     

Determination of suppliers' optimal quantity discount schedules with heterogeneous buyers

Although the quantity discount problem has been extensively studied in the realm of a single supplier and a single buyer, it is not well understood when a supplier has many different buyers. This paper presents an analysis of a supplier's quantity discount decision when there are many buyers with different demand and cost structures. A common discrete all‐unit quantity discount schedule with many break points is used. After formulating the model, we first analyze buyers' responses to a general discrete quantity discount schedule. This analysis establishes a framework for a supplier to formulate his quantity discount decision. Under this framework, the supplier's optimal quantity discount schedule can be formulated and solved by a simple non‐linear programming model. The applicability of the model is discussed with an application for a large U.S. distribution network. © 2002 John Wiley & Sons, Inc. Naval Research Logistics, 49: 46–59, 2002; DOI 10.1002/nav.1052     

一类比率型捕食系统的定性分析

研究一类比率型捕食者-食饵模型dxdt=x(a-bx)-x2c+x2myy2dydt=y(-r+x2d+xm2y2),应用微分方程定性理论,得出该系统极限环的存在性与正平衡点的全局渐近稳定性的充分条件。