两栖装甲车辆水上转向性能的测试与分析

为提高两栖装甲车辆水上转向性能,对其水上转向性能及影响因素进行了分析,探讨了相应的试验方法,在对比试验研究的基础上,给出了应增设专门水上转向机构的结论。     

Flexible capacity strategy in an asymmetric oligopoly market with competition and demand uncertainty

This article studies flexible capacity strategy (FCS) under oligopoly competition with uncertain demand. Each firm utilizes either the FCS or inflexible capacity strategy (IFCS). Flexible firms can postpone their productions until observing the actual demand, whereas inflexible firms cannot. We formulate a new asymmetrical oligopoly model for the problem, and obtain capacity and production decisions of the firms at Nash equilibrium. It is interesting to verify that cross‐group competition determines the capacity allocation between the two groups of firms, while intergroup competition determines the market share within each group. Moreover, we show that the two strategies coexist among firms only when cost differentiation is medium. Counterintuitively, flexible firms benefit from increasing production cost when the inflexible competition intensity is sufficiently high. This is because of retreat of inflexible firms, flexibility effect, and the corresponding high price. We identify conditions under which FCS is superior than IFCS. We also demonstrate that flexible firms benefit from increasing demand uncertainty. However, when demand variance is not very large, flexible firms may be disadvantaged. We further investigate the effects of cross‐group and intergroup competition on individual performance of the firms. We show that as flexible competition intensity increases, inflexible firms are mainly affected by the cross‐group competition first and then by the intergroup competition, whereas flexible firms are mainly affected by the intergroup competition. Finally, we examine endogenous flexibility and identify its three drivers: cost parameters, cross‐group competition, and intergroup competition. © 2017 Wiley Periodicals, Inc. Naval Research Logistics 64: 117–138, 2017     

略论曾中生的军事实践与理论

曾中生是中国工农红军高级指挥员,军事家。他早年投身革命运动,在20世纪30年代参与领导指挥鄂豫皖红军的建设和作战,是鄂豫皖苏区的主要领导人之一,并参与领导创建川陕苏区,对红四方面军的成长壮大,对鄂豫皖和川陕苏区的建立和发展,做出了不可磨灭的贡献。其军事理论建树主要体现在3个方面：红军建设的基本原则、方针与方法,红军作战的战役战术原则,动员群众参战的原则、方法与瓦解敌军的斗争策略。     

A multifaceted heuristic for the orienteering problem

The orienteering problem involves the selection of a path between an origin and a destination which maximizes total score subject to a time restriction. In previous work we presented an effective heuristic for this NP-hard problem that outperformed other heuristics from the literature. In this article we describe and test a significantly improved procedure. The new procedure is based on four concepts—center of gravity, randomness, subgravity, and learning. These concepts combine to yield a procedure which is much faster and which results in more nearly optimal solutions than previous procedures.     

59式57mm高射炮炮管疲劳寿命的工程分析

本文应用Schmitt-Keim方法对59式-57mm高射炮炮管内壁表面裂纹的疲劳寿命进行计算,并对计算结果进行回归分析,得出计算该炮管各种裂纹疲劳寿命的近似公式。结果表明当内壁具有常见的短而浅的裂纹时,其疲劳寿命大于磨损寿命。     

人体静电瞬态电位测试研究

本文在评述人体静电电位测试方法的基础上,指出目前人体电位测试仪器中存在的问题,提出了一种新型测试原理,并研制成 ZPD 型静电测试仪器,用此仪器在弹药防静电危害的现场试验中,测量到人体最高静电电位可达60kv 左右.     

检测柴油机燃油喷射系统的卡持式传感器

介绍了目前柴油机燃油喷射系统技术状况检测的各种方法及其特点。在此基础上,研制了一种卡持在高压油管上的传感器,试验结果表明:该传感器能满足喷射系统技术状况不解体检测的要求。     

Integrated scheduling of loading and transportation with tractors and semitrailers separated

Motivated by some practical applications, we study a new integrated loading and transportation scheduling problem. Given a set of jobs, a single crane is available to load jobs, one by one, onto semitrailers with a given capacity. Loaded semitrailers are assigned to tractors for transportation tasks. Subject to limited resources (crane, semitrailers, and tractors), the problem is to determine (1) an assignment of jobs to semitrailers for loading tasks, (2) a sequence for the crane to load jobs onto semitrailers, (3) an assignment of loaded semitrailers to tractors for transportation tasks, and (4) a transportation schedule of assigned tractors such that the completion time of the last transportation task is minimized. We first formulate the problem as a mixed integer linear programming model (MILPM) and prove that the problem is strongly NP‐hard. Then, optimality properties are provided which are useful in establishing an improved MILPM and designing solution algorithms. We develop a constructive heuristic, two LP‐based heuristics, and a recovering beam search heuristic to solve this problem. An improved procedure for solutions by heuristics is also presented. Furthermore, two branch‐and‐bound (B&B) algorithms with two different lower bounds are developed to solve the problem to optimality. Finally, computational experiments using both real data and randomly generated data demonstrate that our heuristics are highly efficient and effective. In terms of computational time and the number of instances solved to optimality in a time limit, the B&B algorithms are better than solving the MILPM. © 2015 Wiley Periodicals, Inc. Naval Research Logistics 62: 416–433, 2015     

现役装备以可靠性为中心的维修分析

以“以可靠性为中心的维修分析”(RCMA)在典型装备的应用实践为例,论述了现役装备进行RCMA的必要性和可能产生的效益及RCMA的过程,提出了现役装备RCMA的特点和正确分析的措施。     

一种快速、高精度光电闭环跟踪算法

为了解决跟踪系统中目标机动所引起的参数变化,提出了一种多模式自适应滤波器,用５个基本滤波器来描述５种典型的目标机动,然后用贝叶斯条件概率对它们分别进行加权。最后,给出了１５个滤波器的基本参数。