分布式灾难恢复系统

分布式灾难恢复系统采用客户层、服务层和管理层3部分组织形式,完成数据的网络备份和恢复,并提供管理功能。系统通过构建分布式远程备份体系结构,采用ACE(自适配通信环境)面向对象构架,线程池和反应器编程模式,实现了网络互连、事件驱动程序设计,完成了备份计划制订、数据备份、数据恢复3个阶段各个模块的功能。     

WindoWs NT环境下双网卡冗余备份技术

通常在WindowsNT系统中安装两块网卡,它们分别有不同的物理地址和IP地址。但在对网络通信可靠性要求高的系统中,需要对网卡进行双冗余备份,一块网卡正常工作,另一块网卡备份。当正常通信的网卡或线路出现故障时能自动地切换到备份网卡。双冗余网卡不同于双网卡,它只能有一个物理地址,一个IP地址,且某个时刻只能有一块网卡工作。本文论述了在WindowsNT系统下如何实现双网卡冗余备份技术。     

基于TCP协议的双机热备份系统

针对指挥控制数据处理计算机是整个指挥控制系统的数据处理中心属于核心部件,其重要性是不言而喻的.为了提高指挥控制系统乃至整个武器系统的可靠性,对指挥控制数据处理计算机进行双机热备份设计.提出了一种对TCP协议进行双机热备份的实现方法,解决了基于TCP协议的上层应用的热备份实现问题,真正达到了服务不断流的要求,并详细阐述了其设计与实现过程.     

双冗余热备份技术的综合控制设备设计与实现

为提高地面装备可靠性,提出一种基于双冗余热备份技术的车载综合控制设备,采用仲裁方式实现状态实时监测及主、备切换功能,同时基于复杂度、可靠性及实现难度考虑,设计一种任务级同步的余度管理方法,通过余度间的通信链路及运行在CPU模块上的任务同步软件模块实现主、备间的任务同步,既满足设备同步需求,同时易于实现,复杂度低。     

公用电脑快速备份与恢复系统软件的技巧

现在电脑的功能越来越强 ,人们每天都离不开电脑。要想提高电脑的使用效率和延长计算机正常工作时间 ,选择一个能快捷对原始系统及常用软件备份与恢复的软件很重要。明智的选择是———GHOST     

基于FPGA+ARM的多路视频采集系统设计

提出了一种基于FPGA+ARM的多路视频采集系统的设计与实现方法。该视频采集系统不仅能对多路快速变化的视频信号进行采集和处理,而且能应用为系统信号发生设备。系统采用FPGA为核心高速时序逻辑控制、接口控制单元,加上嵌入式ARM强大的信号采样控制功能,能够在较低成本下对多路视频信号进行快速准确可靠的获取。     

轻小型舰艇作战系统时空技术设计及发展建议

根据轻小型作战舰艇对其作战系统指挥与控制的特殊要求,通过对系统战术功能时间关系和系统操控与显示的空间需求分析,提出系统硬件和软件紧密配合的设计原理,不但能实现系统的实时火控解算,而且能实现全系统的高度集中指挥与综合控制.同时,结合新技术的发展,对轻小型舰艇作战系统的设计提出若干建议.     

集群式侦察探测防御系统

设计了一种可应用于军事侦察防御及民用灾区救援探测等场合的集群式侦察探测防御系统。立方单元是系统硬件核心,单元系统内集成了携带多种传感器载荷的固定翼无人机、四旋翼无人机、无人车等子系统,并对平台及子系统进行了设计。设定系统工作背景,设计系统使用功能,设定系统工作流程。设计一种四级通信网络,实现系统模块间的信息交融、系统和系统间的协同通信以及系统同外界的信息交换功能;为实现侦察探测和防御任务,设计一种三级指挥控制网络,实现对任务执行智能协同管理、相关的数据处理、任务执行控制等功能。本系统可以实现对目标区域探测侦察和区域通信中继的功能,在民用灾区救援和军事战区侦察防御都可发挥重要作用。     

配电教学训练仿真系统研究与开发

介绍了通过硬件仿真和软件编程实现配电器功能的原理和方法,并通过系统设计方案论证及硬件设计实现了对配电教学训练仿真系统的开发,提出了通过串行通信与PC机通信及在原有系统的基础上进行功能扩展来实现系统升级扩展的方法;软件设计采用去除冗余设计和软件仿真两次简化的模型,由控制软件对系统状态进行控制,节点状态由程序中的状态变量所体现,人机交互软件接收指令数据,并输出至主控计算机.     

网络环境下应用系统的设计

对基于Internet应用系统的结构和一般的设计方法进行介绍,给出了构建In-tranet应用系统的软、硬件组成和基本设计模式.着重分析了ASP动态Web设计技术的原理和功能,最后给出了实现系统的方法和开发工具.     

Mirror,mirror on the wall,who is the most offensive of them all? – Explaining the offensive bias in military tactical thinking

This article explores why the offensive predominates military tactical thinking. With survey results showing an offensive bias among 60 per cent of senior Swedish officers and as many as 80 per cent in the case of the army, it is clear that this is not just a problem of the past but is equally relevant today. The article asks why there is a tendency to perceive and understand offensive tactics as the preferred choice and the way to conduct battle that should be encouraged and preferred. Drawing on existing research and the findings of a pilot study, ten propositions for why the offensive bias exists are tested using a mixed-method approach. Based on the findings, the article develops a model to understand why the offensive dominates military tactical thinking. It is found that the two key constitutive factors behind the offensive bias are military culture and education. These factors most directly and profoundly influence an officer’s identity, perceptions, and thinking. Military culture and education, in turn, work as a prism for four other factors: military history, the theory and principles of war, doctrine and TTPs, and psychological factors.     

Nonperiodic preventive maintenance for repairable systems

As a complex system with multiple components usually deteriorates with age, preventive maintenance (PM) is often performed to keep the system functioning in a good state to prolong its effective age. In this study, a nonhomogeneous Poisson process with a power law failure intensity is used to describe the deterioration of a repairable system, and the optimal nonperiodic PM schedule can be determined to minimize the expected total cost per unit time. However, since the determination of such optimal PM policies may involve numerous uncertainties, which typically make the analyses difficult to perform because of the scarcity of data, a Bayesian decision model, which utilizes all available information effectively, is also proposed for determining the optimal PM strategies. A numerical example with a real failure data set is used to illustrate the effectiveness of the proposed approach. The results show that the optimal schedules derived by Bayesian approach are relatively more conservative than that for non‐Bayesian approach because of the uncertainty of the intensity function, and if the intensity function are updated using the collected data set, which indicates more severe deterioration than the prior belief, replacing the entire system instead of frequent PM activities before serious deterioration is suggested. © 2010 Wiley Periodicals, Inc. Naval Research Logistics, 2010     

串联系统预防维修周期优化策略研究(英文)

针对串联系统建立了基于可靠性约束的预防性维修优化模型,该模型充分考虑到预防维修可以提高系统可靠性的同时,其故障率会随着维修次数的增加而上升,引入役龄回退因子对预防维修活动前后系统性能的动态变化进行了描述.通过实例验证了该优化模型的正确性与可用性,对模型作进一步的扩展,还可用于更一般复杂的串并联系统.     

Westmoreland was right: learning the wrong lessons from the Vietnam War

Fourth Generation Warfare is a theory of contemporary warfare that posits a number of different ideas that are able to shed light on current conflicts. Whilst much of the debate has been concentrated on the linear development of warfare and also on analysis of the current situation of US forces in Iraq, it has resonance for a number of different conflicts taking place in Africa, if only because the US has become involved in contemporary conflicts in Somalia and the Mahgreb. There are clearly significant issues with the US-centric, flawed linear approach to history, but the actual analysis of modes of warfare has much to offer policymakers in a continent that is under-represented in the literature, and is also in danger of being forgotten in the shadow of analysis of Iraq. This paper moves on from criticising the stepped approach to history and looks at patterns of warfare in contemporary Africa, arguing that there is much in the theory that could be used to explain seemingly illogical tactics or patterns, and thus has much to tell policymakers engaged in conflict analysis.

Rebellions can be made 2 per cent active in a striking force, and 98 per cent passively sympathetic.1 ?1. T.E. Lawrence, ‘Science of Guerrilla Warfare’, 1929, published in Malcolm Brown (ed) T.E. Lawrence in War and Peace: An Anthology of the Military Writings of Lawrence of Arabia (London: Greenhill Books, 2005) p.284.      

基于误差校准的多雷达粒子滤波检测跟踪算法

基于粒子滤波的检测前跟踪方法是一种处理弱目标检测与跟踪的有效方法。使用多部雷达对同一目标进行观测,可以提高目标的检测概率和跟踪精度。但雷达系统误差不同,得到的目标量测信息不能直接进行融合。针对多个具有不同系统误差的雷达联合检测跟踪问题,通过将不同雷达的量测信息向前追溯,对误差进行校准,从而消除不同雷达对于同一粒子的量测误差,然后将粒子权重进行融合。仿真结果表明,在雷达具有不同系统误差的情况下,采用本算法可以有效提高目标的跟踪精度。     

A computationally efficient approach for determining inventory levels in a capacitated multiechelon production‐distribution system

The system under study is a single item, two‐echelon production‐inventory system consisting of a capacitated production facility, a central warehouse, and M regional distribution centers that satisfy stochastic demand. Our objective is to determine a system base‐stock level which minimizes the long run average system cost per period. Central to the approach are (1) an inventory allocation model and associated convex cost function designed to allocate a given amount of system inventory across locations, and (2) a characterization of the amount of available system inventory using the inventory shortfall random variable. An exact model must consider the possibility that inventories may be imbalanced in a given period. By assuming inventory imbalances cannot occur, we develop an approximation model from which we obtain a lower bound on the per period expected cost. Through an extensive simulation study, we analyze the quality of our approximation, which on average performed within 0.50% of the lower bound. © 2000 John Wiley & Sons, Inc. Naval Research Logistics 47: 377–398, 2000     

Investigating optimal replacement of aging air force systems

An availability‐oriented approach has been developed to decide when to replace an aging system. For an existing system, it is optimal to operate another year if and only if the incremental cost per available year is less than the lifetime average cost per available year of a new aircraft. We illustrate our approach using United States Air Force KC‐135 tanker data. In demonstrating our approach, we find it will be optimal to replace the KC‐135 by the end of the decade.     

The impact of inventory information distortion due to customer order cancellations

In this paper we study the impact of cancellations of customer orders on an inventory system. We develop a periodic review (s, S) inventory model with Poisson demands, deterministic demand leadtimes and supply leadtimes. When no set up cost is present for replenishment, the behavior of the system cost can be studied analytically. For the case with a fixed set up cost, we derive the operating characteristics of the model via an embedded Markov chain analysis. Based on this, we formulate the total cost function and suggest a two‐phase approach to optimization. Our model can be used to compute cancellation fees and to evaluate the impacts of various conditions of cancellation. We find that cancellations, as major sources of inventory information distortion, increase total system costs, and the magnitude of the cost impact depends on the probability of cancellation and the expected cancellation time. Other relevant lessons and insights are also discussed. © 1999 John Wiley & Sons, Inc. Naval Research Logistics 46: 213–231, 1999     

Optimal state-dependent pricing policies for a class of stochastic multiunit service systems

This paper models a k-unit service system (e.g., a repair, maintenance, or rental facility) with Poisson arrivals, exponential service times, and no queue. If we denote the number of units that are busy as the state of the system, the state-dependent pricing model formalizes the intuitive notion that when most units are idle, the price (i.e., the service charge per unit time) should be low, and when most units are busy, the price should be higher than the average. A computationally efficient algorithm based on a nonlinear programming formulation of the problem is provided for determination of the optimal state-dependent prices. The procedure ultimately reduces to the search on a single variable in an interval to determine the unique intersection point of a concave increasing function and a linear decreasing function. The algorithm takes, on the average, only about 1/2 second per problem on the IBM 360/65 (FORTRAN G Compiler). A discrete optimal-control approach to the problem is shown to result in essentially the same procedure as the nonlinear-programming formulation. Several properties of the optimal state-dependent prices are given. Comparisons of the optimal values of the objective function for the state-dependent and state-independent pricing policies show that the former is on the average, only about 0.7% better than the latter, which may explain partly why state-dependent pricing is not prevalent in many service systems. Potential generalizations of the model are discussed.     

分布式防空C3I系统面向对象建模方法

采用面向对象的建模思想,把分布式防空C3I系统的各个组成部分抽象成对象,从时间、空间和功能的角度对分布式防空C3I系统进行了描述.通过确定对象类、类的属性、操作及类之间的关系而建立了分布式防空C3I系统的对象模型;通过对系统状态转换的分析,建立了分布式防空C3I系统动态模型;通过对系统功能模型的分布,利用层次数据流图建立了分布式防空C3I系统功能模型.