战区弹药保障敏捷供应链优化模型及实现算法

针对现有的供需矛盾,在分析战区弹药保障供应链管理任务需求的基础上,初步构建了战区弹药保障敏捷供应链管理框架及运行机制,分析了战区弹药保障敏捷供应链的供需协同机制,重点对多级库存优化控制模型、多级弹药配送决策优化模型及实现算法进行了研究,提出了战区弹药保障敏捷供应链建设的具体对策。     

一个具有阶段结构的食物链模型的稳定性

研究一个具有阶段结构的食物链模型,通过构造Lyapunov函数并利用LaSalle不变性原理分别给出了保证系统各平衡点全局稳定的充分条件。     

基于车载式武器系统抑制火炮抖动的模型研究

针对车载集中式武器系统对目标的跟踪出现火炮抖动现象,研究了武器系统控制火炮的机理并对火炮方位架位控制采取进行了详细地分析,提出了一种解决火炮抖动的方法：改进火炮方位控制传动链。仿真和试验表明该方法在保证目标跟踪过程中火炮平稳运转方面有效、可行。     

基于多模型组合的模拟电路故障诊断方法

针对传统模拟电路故障诊断方法识别准确率低及耗时较长的问题,提出一种基于改进的二进制粒子群优化算法(IBPSO)与隐马尔科夫模型(HMM)的综合诊断方法。该方法利用IBPSO对故障特征进行提取优化,降低故障特征维度,进一步利用HMM对提取的故障特征进行预处理,排除不可能类故障特征,提高了LSSVM的分类准确率。经过仿真结果分析验证,该方法较现有的BP神经网络诊断方法,能够在确保正确率得到提升的基础上,进一步提高故障诊断速度,具有更强的战场环境适用性。     

把目标威胁纳入性能指标的目标分配方法

武器系统目标分配是作战指挥中的一个重要问题。提出了把目标威胁纳入性能指标,建立在马尔可夫动态系统输入过程最优化基础上的目标分配方法     

一类马尔可夫人才系统中的工龄和职龄

用马尔可夫模型研究人才系统中工龄和职龄问题的一般方法都要按职务等级、工龄或职龄来划分系统状态。本文在只以职务等级划分系统状态的一类无降级且逐级晋升的齐次马尔可夫人才系统中讨论了工龄和职龄问题,得到直观描述工龄和职龄的计算结果,并通过一实例说明了本方法的应用价值。     

Fixed‐interval joint‐replenishment policies for distribution systems with multiple retailers and stochastic demand

We consider a distribution system consisting of a central warehouse and a group of retailers facing independent stochastic demand. The retailers replenish from the warehouse, and the warehouse from an outside supplier with ample supply. Time is continuous. Most previous studies on inventory control policies for this system have considered stock‐based batch‐ordering policies. We develop a time‐based joint‐replenishment policy in this study. Let the warehouse set up a basic replenishment interval. The retailers are replenished through the warehouse in intervals that are integer multiples of the basic replenishment interval. No inventory is carried at the warehouse. We provide an exact evaluation of the long‐term average system costs under the assumption that stock can be balanced among the retailers. The structural properties of the inventory system are characterized. We show that, although it is well known that stock‐based inventory control policies dominate time‐based inventory control policies at a single facility, this dominance does not hold for distribution systems with multiple retailers and stochastic demand. This is because the latter can provide a more efficient mechanism to streamline inventory flow and pool retailer demand, even though the former may be able to use more updated stock information to optimize system performance. The findings of the study provide insights about the key factors that drive the performance of a multiechelon inventory control system. © 2013 Wiley Periodicals, Inc. Naval Research Logistics 60: 637–651, 2013     

The defence firm of the future

This paper offers the personal view of a senior executive in the Defence Procurement Agency about the future requirements of the defence industry’s principal UK customer. The focus here is on trying to identify the type of corporate behaviour and range of skill sets that the UK Government will need from defence suppliers, both primes and supply chain companies in the future. The concluding message from this ‘Customer View’ is that there is likely to be a continuing market for the company that specializes in delivering defence capability. It will be a company that will be looking for a long‐term relationship, with a specialist knowledge of its various national customers and a willingness to work openly and closely with them. It will be agile in its ability to bring together diverse technologies, to package them as a system and to deliver them either as hardware or as a service. Such suppliers will also need to innovate and to adapt at least as rapidly as the threats that they seek to counter.     

A 17th-century Pikeman's Armour from Antwerp

Abstract

A recent re-examination of the arms and armour collection at the British Museum has led to the identification of a 17th-century pikeman's armour clearly associated with the city of Antwerp in modern Belgium, the only example of its kind. The three pieces: a pot, breastplate and backplate, are part of a collection bequeathed to the museum by William Burges in 1881. All three pieces can be dated to circa 1635 and are stamped with the arms of Antwerp, a stylised depiction of Antwerp castle between two hands derived from the blazon of the Margrave of Antwerp. The armour is indistinguishable from contemporary Dutch production and it is unclear whether it was made in Antwerp or whether the addition of the arms simply suggests a use in the city.     

JXTA网络短链路由改进算法

JXTA为构建对等网络提供了标准化计算平台,制定一些协议和服务专门解决构建P2P网络所遇见的问题.为了改进JXTA路由查询效率低下问题,提出一种路由短链改进算法.在端点路由协议的基础上,根据小世界短链现象采用物理邻居策略将网络划分簇,簇内采用Pastry算法,簇间运用freePastry算法进行资源搜索,使长跳路由减少短链路由增加.通过仿真实验说明,算法可有效增加检索效率,减少节点间的通讯时延.