The one‐warehouse multiretailer problem with an order‐up‐to level inventory policy

We consider a two‐level system in which a warehouse manages the inventories of multiple retailers. Each retailer employs an order‐up‐to level inventory policy over T periods and faces an external demand which is dynamic and known. A retailer's inventory should be raised to its maximum limit when replenished. The problem is to jointly decide on replenishment times and quantities of warehouse and retailers so as to minimize the total costs in the system. Unlike the case in the single level lot‐sizing problem, we cannot assume that the initial inventory will be zero without loss of generality. We propose a strong mixed integer program formulation for the problem with zero and nonzero initial inventories at the warehouse. The strong formulation for the zero initial inventory case has only T binary variables and represents the convex hull of the feasible region of the problem when there is only one retailer. Computational results with a state‐of‐the art solver reveal that our formulations are very effective in solving large‐size instances to optimality. © 2010 Wiley Periodicals, Inc. Naval Research Logistics, 2010     

带有可信度因子的直觉模糊近似推理方法

针对基于相似度的直觉模糊近似推理问题,提出一种基于加权相似度量的直觉模糊推理方法。首先定义一种新的直觉模糊相似度度量公式,加入权重参数解决各维特征分配不均匀的问题,弥补了现有直觉模糊相似度量的缺陷。然后构建基于直觉模糊产生式规则的直觉模糊近似推理模型,加入可信度因子解决了随机性引起的信息不确定问题,同时给出模型的推理算法和计算步骤。最后通过实例验证了该方法的实用性和有效性,其在意图识别、目标识别等信息融合领域有良好的应用前景。     

美军信息系统互操作性研究

解释了军事信息系统互操作性的内涵,对美军信息系统互操作性研究现状如信息系统互操作性等级模型、美国国防部体系结构框架及国防信息基础设施总体规划等进行了详细阐述。进一步分析了美军发展军事信息系统互操作性的内容,为实现我军各信息系统的互操作性提供参考。     

Why internal conflict deteriorates state capacity? Evidence from Colombian municipalities

Previous work has documented a negative correlation between internal conflict and state capacity. We attempt to shed light on mechanisms that underlie this relationship, using data for Colombian municipalities. We rely on identifying heterogeneous effects of different types of violent events on state capacity, taking advantage of variability across municipalities in the prevalence of specific manifestations of conflict and their intensity. Our findings suggest that events making civilians feel targeted affect the state’s capacity to collect taxes, while those reflecting a stronger military capacity of illegal armies, in particular their large-scale attacks, affect the state’s capacity to provide public goods.     

An optimal critical level policy for inventory systems with two demand classes

Traditional inventory systems treat all demands of a given item equally. This approach is optimal if the penalty costs of all customers are the same, but it is not optimal if the penalty costs are different for different customer classes. Then, demands of customers with high penalty costs must be filled before demands of customers with low penalty costs. A commonly used inventory policy for dealing with demands with different penalty costs is the critical level inventory policy. Under this policy demands with low penalty costs are filled as long as inventory is above a certain critical level. If the inventory reaches the critical level, only demands with high penalty costs are filled and demands with low penalty costs are backordered. In this article, we consider a critical level policy for a periodic review inventory system with two demand classes. Because traditional approaches cannot be used to find the optimal parameters of the policy, we use a multidimensional Markov chain to model the inventory system. We use a sample path approach to prove several properties of this inventory system. Although the cost function is not convex, we can build on these properties to develop an optimization approach that finds the optimal solution. We also present some numerical results. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008     

指挥信息系统需求体系框架

需求工程是指挥信息系统整个开发周期中的第一步,正确且全面地确认系统的需求是成功开发指控系统的关键.指挥信息系统需求体系框架是从需求开发的内容上规范需求工程技术在指挥信息系统需求开发中的应用.从需求的本义出发,在分析总结IEEE、INCOSE以及OMG等研究机构关于需求内涵与分类的研究基础上,本着与C4ISR/DOD AF一致的原则,结合近年我军指挥信息系统需求开发的实践经验,提出了指挥信息系统需求体系框架.     

基于事务级模型的火控计算机建模研究

在对系统进行高层次建模和验证时,事务级模型得到越来越广泛的应用。在SystemC语言的基础上构建了火控计算机的事务级模型,并通过事务级的仿真,对模型的功能进行了验证,为下一步的软硬划分和硬件设计打好基础。     

武器握把舒适度量化研究

以手枪的握持舒适度试验为依据,分析影响握把舒适度的因素,提取舒适度量化特征点,并在试验结果的基础上,给出舒适度量化特征值。     

装备预防性维修的维修级别逻辑决策分析方法

针对预防性维修的维修级别没有规范、统一的分析与确定方法的问题,研究了预防性维修的维修级别逻辑决策分析方法。明确了预防性维修的维修级别决策分析的对象是预防性维修工作类型,预防性维修主要有定时维修和状态维修,定时维修分为定时拆修和定时报废2种维修工作类型,状态维修分为状态信息检测、状态识别、状态预测、维修决策、故障诊断和维修实施等维修工作类型。根据维修间隔期、维修能力评估、其它非经济性因素以及经济性分析,分别建立了定时维修和状态维修的维修级别逻辑决策模型。     

苯胺类环境污染物与生物蛋白分子相互作用

建立了一种基于毛细管电泳(CE)技术的改进型前沿分析(IFA)法,用于致癌性有机环境污染物联苯胺(BZ)与牛血红蛋白(BHb)的相互作用研究,分别采用Scatchard方程和Klotz方程,求解它们的相互作用结合常数和结合位点数。初步建立起CE/IFA,减小了实验误差,提高了测定结果的准确度。在比较研究CE/PS和CE/IFA基础上,验证了改进后的毛细管电泳前沿分析法的可靠性。同时讨论了改进型前沿分析法在测定分子间相互作用结合常数方面的优点。