Solving generalized transportation problems via pure transportation problems

This paper investigates certain issues of coefficient sensitivity in generalized network problems when such problems have small gains or losses. In these instances, it might be computationally advantageous to temporarily ignore these gains or losses and solve the resultant “pure” network problem. Subsequently, the optimal solution to the pure problem could be used to derive the optimal solution to the original generalized network problem. In this paper we focus on generalized transportation problems and consider the following question: Given an optimal solution to the pure transportation problem, under what conditions will the optimal solution to the original generalized transportation problem have the same basic variables? We study special cases of the generalized transportation problem in terms of convexity with respect to a basis. For the special case when all gains or losses are identical, we show that convexity holds. We use this result to determine conditions on the magnitude of the gains or losses such that the optimal solutions to both the generalized transportation problem and the associated pure transportation problem have the same basic variables. For more general cases, we establish sufficient conditions for convexity and feasibility. © 2002 Wiley Periodicals, Inc. Naval Research Logistics 49: 666–685, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/nav.10034     

惯性导航系统故障诊断的不确定性问题研究

针对构造惯性导航系统 ( INS)故障诊断所面临的确定性和不确定性问题 ,提出了基于模糊集理论的诊断方法 ,并给出诊断系统自动获取不确定性证据和确定性证据隶属度的方法及函数 .认为对于确定性证据和不确定性证据可以用统一的方法和原则来处理 ,并建立了两类证据的实用数学模型     

对办好高等院校研究生课程进修教育的思考

近年来,高校纷纷举办各种形式多样的在职研究生课程进修班,针对这一新生的、过热的教育形式,本文从其定位和目前存在问题等方面进行系统分析,并提出了进一步办好研究生课程进修班的措施.     

析通信线路消防安全管理方面存在的问题

针对我国通信行业与公安消防部门就通信线路和建构筑物之间安全距离规定不统一 ,分析我国通信线路消防安全管理方面存在的问题 ,并提出改进通信线路消防安全管理的建议     

Incomplete contracting and target‐cost pricing

Procurement of advanced technology defence equipment requires appropriate contractual arrangements to achieve efficient R&D investments. This paper analyses the optimality of target‐cost and fixed price contracts and shows that target‐cost pricing can achieve a first best where both fixed‐price contracts and cost reimbursement fail to do so. The main message of this paper is that in incomplete contracting optimality may sometimes be achieved by arrangements which combine several formulae which, individually, would fail to achieve efficiency.     

Facility location for an extraterrestrial production/distribution system

This paper extends traditional production/distribution system analysis to address raw material, factories, and markets located beyond Earth. It explains the eventual advantages of such operations and discusses likely sites in the solar system. It furnishes a typology for production/distribution systems, assessing the fit of each type to space operations. It briefly reviews the physics of orbits. It develops transportation and inventory cost functions for the simplest case of Hohmann trajectories, and for transportation between circular orbits of similar radii using higher‐energy trajectories. These cost functions are used to derive a model of production/distribution system cost, the minimization of which selects an optimal factory location. The paper suggests potential extensions to this work, and concludes with ideas for location research on the novel reaches of extraterrestrial space. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2005.     

坦克稳定器和电气故障诊断系统

现役59式坦克稳定器和电气系统,由于研制时测试性设计不周,在使用中一旦发生故障,如何迅速排除,在部队一直是个老大难问题.使用本故障诊断系统,能够指导维修人员快速找到发生故障的部件或外部电路;可以在显示器上用颜色作相应变化的电路图,一步步演示出故障压缩过程,直至最后找出故障部位.本文将介绍该系统的功能、技术方案、技术关键及使用特点.     

不完全维修策略的产品保修期研究

以保修期内的保修费用和可用度2个目标作为优化决策依据,权衡厂家和顾客的利益及需求,建立基于改善因子的不完全预防性维修模型,并通过实例确定厂家和顾客共同达到最大满意度的最佳维修间隔期及保修期,验证了模型的实用性。     

大型消防装备采购模式及全寿命期费用控制问题探析

大型消防装备采购模式存在的一些问题,影响了大型消防装备全寿命期的经费使用效益,导致大型消防装备的购置费用高而效率低,装备闲置和利用率不高,装备全寿命期费用控制效果较差,必须建立大型消防装备全寿命费用管理体系,提高大型消防装备投资的效率。     

基于多假设跟踪弹道导弹主动段跟踪算法

针对弹道导弹主动段防御中多枚弹道导弹同时跟踪问题,提出了基于多假设思想的主动段跟踪算法.重点阐述了该算法中假设生成、假设概率计算、假设约简以及假设剪枝等环节.从工程实用的角度出发,采用求解一个线性分配问题(LAP)方法得到M个最优假设,大大减少了假设数量,并运用N-scan回溯剪枝方法对假设进行剪枝,确定要输出的航迹,提高了算法的效率和实用性.仿真实验表明,该算法能够对主动段多枚弹道导弹目标准确关联跟踪.