分布式探测系统的时延估计和稳定性分析

分布式探测系统实现了探测控制系统的分布化和网络化,但由于网络信息传输时延的存在,使得信息传输实时性受到诸多条件的影响。为此,在分析分布式探测系统时延特性的基础上,利用MATLAB/Truetime工具箱实现系统的建模仿真,针对不同网络延时、丢包、干扰等情况对系统稳定性能进行了对比分析。仿真结果表明:网络时延增大是影响系统稳定性能的主要因素,仿真流程对于网络探测的硬件系统构成和通信协议设计具有指导性意义。     

航空发动机分布式系统解耦控制研究

航空发动机控制系统是一个复杂的多变量控制系统,控制变量之间的相互耦合会严重影响系统的动态、稳态性能,在发动机最大工作状态时,甚至会造成超温、超转等现象,严重威胁着飞行安全,制约着发动机性能的提高。针对上述情况,利用改进型遗传算法对航空发动机双回路PID控制参数进行寻优,实现了对控制变量的解耦。数值仿真结果表明改进方法能有效消除各变量之间的耦合影响,而且在控制精度、跟踪性能等方面表现良好,对不同环境条件下的航空发动机模型均有良好的控制效果,适用于航空发动机控制。     

基于Matlab的岸舰导弹部队指挥决策系统仿真

在海军岸舰导弹部队指挥决策系统设计中,首先需要对系统模型进行仿真,以确定系统构造的合理性.岸舰导弹部队指挥决策系统是海军基地作战指挥自动化网的重要组成部分,针对系统特点,运用Matlab(一种高级仿真语言)中的模糊逻辑工具箱,设计了模糊推理系统,对岸舰导弹部队指挥决策进行了仿真.仿真结果表明,运用Matlab模糊逻辑工具箱进行决策仿真,建立系统隶属度函数和模糊规则非常快捷、方便,输出结果直观.在实际应用中,通过Matlab外部程序接口技术,该仿真结果已经很好地应用到了某智能作战指挥决策系统中.     

陆战平台分布式综合模块化系统架构建模方法

分布式综合模块化系统架构,成为航空应用领域的主流架构和发展趋势.我国空军已进行了分布式综合模块化系统架构研究设计和仿真评估,但缺乏系统级的架构优劣评估.兵器领域已将综合模块化系统架构应用于型号项目中,但在分布式综合模块化架构方面,尚未在具体项目中应用.针对分布式综合模块化系统架构缺乏系统级评估手段的问题,提出一种陆战平台分布式综合模块化系统架构建模方法.根据系统架构评估需求,建立不同层级实体的模型及约束,分别对应陆战平台信息控制系统的业务层、操作系统分区层、模块层、子系统层、系统层;在层级划分的基础上,定义各层级模型的属性;通过对评估指标中的综合度、耦合度进行评估计算,对系统架构建模方法进行验证.系统架构建模方法为系统架构评估提供了一种参考.     

基于发动机恒转速控制的干式DCT车辆智能起步研究

分析了起步过程中影响离合器接合速度的主要因素,基于发动机恒转速控制方式和双离合器联合起步,设计了驾驶意图模糊推理系统、离合器接合速度推理系统、离合器分离条件推理系统3个智能控制系统,对起步的挡位、发动机转速、离合器接合速度进行控制,并对其进行了仿真。仿真结果表明:应用模糊控制能很好地控制DCT车辆双离合器联合起步。     

军用发动机控制系统技术分析及改进研究

控制系统是航空发动机的重要组成部分。文章对国外航空技术强国,特别是美国和俄罗斯的航空发动机控制系统技术的发展历程进行了分析,着重介绍了某发动机控制系统的技术特点。针对该发动机控制系统提出了数字化改进方案,可以有效减轻控制系统重量,挖掘发动机潜力,并提升发动机性能。从航空发动机控制系统的发展历程可以看出,全权限数字电子控制技术(FADEC)是航空发动机控制系统发展的必然趋势,会对航空技术的发展产生巨大的推动作用。     

混沌蝙蝠算法UAV网络控制系统故障诊断策略

针对总线条件下具有双通道多包传输的短时变时延无人机(Unmanned Aerial Vehicle,UAV)发动机控制系统,提出一种基于改进蝙蝠优化算法(Bat Algorithm,BA)的发动机故障检测算法,快速变化的延迟被认为是系统不确定性的一种。残差信号的传递函数与噪声和故障信号的传递函数之比用作目标函数。通过改进的Bat算法对其进行优化,以获得最佳的观察增益矩阵,使得该故障观测器系统不仅能够抑制噪声,而且对提升对故障敏感程度。最后将该方法在网络控制系统半物理平台上进行仿真,仿真结果说明所提出的方法能够同时抑制噪声信号和放大故障信号,从而提高了故障诊断的正确率,降低了虚警率。     

离散网络控制系统的时变时延稳定性分析

针对依赖网络时延的离散时间网络化控制系统的不稳定性问题,通过选取恰当的李亚谱诺夫泛函并利用新的矩阵不等式界定方法,得到了依赖于时滞上、下界的系统鲁棒均方渐近稳定的充分条件。该稳定性条件描述了网络状态相关变量间的联系,因此具有较小的保守性。仿真结果表明了该方法的有效性。     

基于磁记忆的铁磁性构件定量无损检测研究

为提高磁记忆检测结果的稳定性,设计匀速采样系统,并且针对系统的实验结果进行分析。由实验结果得出提离值对系统稳定性的影响较小,扫描速度对检测结果稳定性的影响较大。     

微型涡喷发动机起动控制系统设计

针对微型涡喷发动机起动过程稳定性较差的特点,设计了一种基于模型参考自适应控制(MRAC)算法的起动控制系统.通过采用基于多传感器的自适应控制方法,减小发动机建模误差和外界干扰的影响,以提高起动过程中系统的鲁棒性.试车实验结果表明:该方法使微型涡喷发动机在一定外界条件下快速、平稳地起动,降低了发动机贫油、富油和喘振的可能性,保证发动机可靠起动.     

Helping hands: civil–military cooperation and Italy's military operation abroad

In the Post-Bipolar Era the growing complexity of the military operations requires a new approach for the resolution of international crises. Since the end of the Cold War, peace support operations (PSO) have become the mainstay and principal occupation of most Western armies. At the same time, Italy has been one of the most important actors in such an area. The article focuses on the cooperation between military and civil components (a process called CIMIC) as a key variable in the Italian PSOs. We will analyse in detail the main lessons learned from past military interventions as well as the general context in which new tendencies are taking place. The maintaining of a minimum security frame becomes essential to fulfil activities ‘collateral’ to the mission: reconstructing services and infrastructure, food distribution, water and medication, law and order, de-mining, training of local forces, and supporting local institutions. These are the main tasks to obtain thrust and support from the population.     

Terrorism,insurgency, kidnapping,and security in Africa's energy sector

Energy continues to serve as the bedrock of modern economies and the main driver of modern society. For Africa, the production and supply of energy resources such as crude oil, natural gas, uranium, coal, biomass, biofuels and other renewables are an important source of employment, rents, taxes, royalties and profits. This sector brings in several tens of billions of dollars of revenue annually. The production and delivery of such resources, however, depend on critical infrastructures such as pipelines, refineries, processing plants, terminals, rigs, electrical energy pylons, substations, pump stations, vessels, and tankers. These infrastructures have been attacked by terrorists, insurgents, vandals and saboteurs, all of whom see them as targets against which to register their grievances and extract concessions from the state. This paper is a chronological account of some of the documented incidents of terrorism, insurgency, kidnapping, destruction, sabotage, and human casualties suffered in the oil and gas sectors in Africa between 1999 and 2012. It is based on data extracted from the databases of the RAND Database of World Terrorism Incidents and the University of Maryland's Global Terrorism Database (GTD).     

Tacit support for terrorism: The rapprochement between the USSR and Palestinian guerrilla organizations following the 1967 war

This article demonstrates the inconsistent and wavering Soviet attitude towards national liberation movements in general and the Palestinian organizations in particular. Until the late 1960s, the Soviets viewed these organizations with suspicion, hesitating to engage in political dialogue with them. However, in the 1970s, political and military events in the region, as well as modifications in the Kremlin's Cold War strategies, led to a general shift towards the Middle East in Soviet foreign policy. Soviet leaders showed increased willingness to provide certain Palestinian organizations with arms with which to conduct terrorist activities against Israeli, pro-Israeli, Jewish and Western targets. The article explores the complex relations between Palestinian organizations and the USSR in the field of international terror. The study also exposes and analyzes the nature and content of Soviet–Palestinian arms dialogues and transactions. It provides clear evidence that Soviet policymakers and other luminaries were fully informed of, and sometimes directly involved in, these transactions and dialogues at the highest levels.     

A1 Qaeda and the radical Islamic challenge to western strategy

The September 11 global crisis prompted by the attacks on the World Trade Center and the Pentagon raises major questions concerning the nature and trajectory of terrorism in the post-Cold War global order. Hitherto, terrorism has been largely debated by analysts at the level of nation states. Terrorist and insurgent movements have also been largely anchored in nationalist and ethnic power bases even when they have sought to mobilise a transnational ideological appeal on religious or class grounds. There have been a few exceptions to this pattern such as the alliance between the German Baader-Meinhof group and the Japanese Red Army Faction, but even such international alliances as this did not, until at least the 1980s, presage anything like a global terrorist network necessitating a global strategic response. This study examines terrorism and global strategic responses.     

Helping hands: external support for the KNU insurgency in Burma

This article analyses to what extent the Burmese KNU insurgency made use of external support from states, refugees, and diasporas. Based on extensive fieldwork it is concluded that support from neighbouring states and refugees has for years kept the Karen rebellion alive. Western countries perceived forms of resistance to the illegitimate Burmese regime as just and have therefore played a crucial role in the continuation of conflict in Karen State. It is important that policymakers and donors as well as executing organizations continue to reflect critically on the way they exercise their work.     

Reviews

Douglas S. Derrer, We Are All the Target: A Handbook of Terrorism Avoidance and Hostage Survival. Annapolis, MD: US Naval Institute Press, 1992. Pp. x+135, notes, index. $14.95. ISBN 01–55750–150–5

Ian Knight, Zulu: Isandlwana and Rorke's Drift, 22–23 January 1879. London: Windrow & Greene, 1992. Pp.136, 150 illus., incl 8 colour plates, maps, biblio. £35. ISBN 1–872004–23–7

Ian Knight, By the Orders of the Great White Queen: Campaigning in Zululand through the Eyes of the British Soldiers, 1879. London: Greenhill Books and Novato: Presidio Press, 1992. Pp. 272, 17 illus., 1 map. £18.95. ISBN 1–85367–122–3

Manfried Rauchensteiner and Erwin A. Schmidl (eds.), Formen des Krieges: vom Mittelalter zum ‘Low‐intensity’ Conflict’. Graz : Verlag Styria, 1991. Pp.208. DM35. ISBN 3–22–12139–7

Harold J. Kearsley, Maritime Power and the Twenty‐First Century. Dartmouth: Dartmouth Publishing Company, Limited, 1992. Pp.xv + 203, 13 diagrams, index. £32.50. ISBN 1–85521–288–9     

基于GTST-DMLD-ESD的装备RMS建模仿真

装备的RMS是装备的重要设计参数,是影响战备完好和保障能力的关键因素.引入GTST-DMLD作为主要建模工具,建立起装备系统的RMS描述模型,以ESD为补充和扩展,对维修过程进行建模.并以GTST-DMLD-ESD模型作为装备RMS仿真的核心,对装备RMS仿真模型的总体框架进行了研究,并对各模块进行了较为详细的探讨.     

Cyber sheiks and grassroots jihadis: the war in Syria and the devolution of the Bosnian Salafi communities

ABSTRACT

What was the scope of the Bosnian jihadi participation in the war in Syria? Did the Bosnian volunteers tend to join one particular faction? Why did the Bosnian youngsters decide to join the holy war in the Levant? Was this an organized and hierarchical process or was this a grassroots movement? Last, were all the Salafis in Bosnia supportive of this dynamic or did this process cause internal frictions? These are some of the questions that this research will try to answer.