双源平行激光光幕系统安装误差分析

针对一种双源平行激光光幕系统存在安装误差的问题,以单侧光幕的检测阵列为研究对象,建立了测试坐标误差计算模型,分析了不同安装误差对测试结果的影响。利用MATLAB对1 m×1 m的测试靶进行了数值仿真,确定了一组安装误差值,分别为竖直方向偏移4 mm,竖直方向偏转10',水平方向偏转1°,以此作为测试系统安装调整的依据。当安装误差控制在此数值范围内时,其对测试结果造成的影响可以接受。最后通过实弹射击,验证了理论分析的正确性。     

磁梯度张量的旋转计算方法

为了获得磁梯度张量数据,提出旋转计算磁梯度张量的方法。使倾斜放置的磁梯度计绕竖直轴线转动,利用测得的空间磁梯度数据计算得到磁梯度张量。以磁梯度张量的理论值作为参考,选取一组较优的转动角、倾角和基线长度等模型参数,分析磁力仪三轴指向误差对磁梯度张量计算结果的影响。数值仿真结果表明:该旋转合成方法能够有效获取磁张量信息,合成计算值与理论值之间的差别较小。     

一种六加速度计无陀螺惯性导航系统安装误差校准方法研究

针对加速度计安装方向和位置向量补偿的问题,理论上推导了一种六加速度计无陀螺惯性导航系统安装误差校准方法,通过重力效应进行加速度计方向向量的校准,通过载体旋转产生的向心加速度进行位置向量的校准,然后利用校准的结果进行加速度计输出补偿,并进行了计算机数字仿真。仿真结果表明,经加速度计安装校准和补偿,系统精度可提高600倍以上,验证了该方法的有效性。     

基于倾斜平台的舰炮武器系统零位修正方法

分析了舰炮基座平台倾斜误差较大时对系统零位一致性和精度造成的影响,提出了采用单炮基座倾斜修正和对系统瞄星数据补偿的改进修正方法进行系统零位一致性的精确调整,并给出修正公式的推导过程.以试验实测数据对修正精度进行了验证,结果表明该方法具有较好的实用价值.该方法已在某型舰炮武器系统的海试中得到了成功应用.     

Bang-Bang控制方式旋转导弹气动特性数值分析

为研究Bang-Bang控制式鸭舵对旋转导弹气动特性的影响,在CFD软件中采用嵌套网格方法模拟导弹的旋转和鸭舵的偏转,对Bang-Bang控制式旋转导弹在不同攻角、马赫数和转速下的气动特性进行了数值模拟,得到了气动特性变化规律。研究表明,因鸭舵洗流方向的改变,耦合导弹自旋会导致弹体和尾翼的侧向力发生突变。通过与不控鸭舵的旋转导弹进行对比,采用Bang-Bang控制式鸭舵的旋转导弹的周期平均侧向力系数变小,周期平均法向力系数变大。由于侧向力的存在,导弹在一个周期内的合力会偏离竖直方向,合力偏离竖直方向的角度随着马赫数、自旋速率和攻角的增大而减小。     

多坐标系中的分布式和联邦式数据融合算法

在坐标转换误差条件下,引入kalman滤波算法的两个重要公式.分析多坐标系传感器系统中分布式kalman滤波算法的特点.在此基础上提出一种改进的联邦式滤波算法.新算法中.通过对量测方程和坐标转换方程的变换,使得本地处理器利用本地坐标系中的量测值,通过kalmam滤波算法直接得到参考坐标系下的状态值.相应的,kalman滤波算法也要根据这种数学变形作适当的修正.这样,在联邦式算法中,仅仅需要一次坐标转换就可以得到状态的全局估计,因此,滤波精度比分布式算法有所提高.仿真的结果也证实了这种性能的改进.     

重力扰动对SINS水平姿态的影响

为研究动基座下捷联惯导系统(Strapdown Inertial Navigation System, SINS)水平姿态误差角与水平重力扰动间的关系,推导了南北方向、东西方向匀速直线运动时,SINS纯惯性解算的水平姿态误差与水平重力扰动间的传递函数,并分析了传递函数的零极点分布;推导了组合导航模式下,水平姿态误差角与水平重力扰动间的传递函数;通过仿真分析了纯惯性解算和组合导航模式下传递函数的幅频特性。组合导航相对于纯惯性解算模式,截止频率更大,SINS姿态误差角受更多高频重力扰动信号的影响,因此,组合导航模式需要更高分辨率的重力扰动数据来进行重力扰动补偿。此外,在对高精度SINS进行重力扰动补偿时,对于重力扰动分辨率的需求是有限度的,过于精细的重力扰动数据只会带来测量和存储压力,不能提高SINS的姿态精度。     

命中角对防护结构口部爆炸毁伤影响的数值分析

为研究装药命中角对防护结构口部爆炸毁伤的影响规律,对直墙拱结构进行了一系列爆炸模拟分析,得到了直墙拱结构拱顶、拱脚和直墙底3个位置的爆炸应力和位移时程曲线。通过分析这3个位置的应力峰值和位移峰值,发现随着装药命中角的增大,拱顶处竖直方向荷载减小,而拱脚处水平方向荷载增大;随着装药命中角的增大,拱顶处竖直方向位移变形减小,而拱脚处水平方向位移变形增大。模拟分析得到的命中角对防护结构口部爆炸毁伤的影响规律,可供防护工程设计时参考。     

用象限仪标定炮耳轴倾斜传感器的误差分析

论证了长期以来存在的用象限仪标定炮耳轴倾斜传感器的方法误差.通过理论分析建立了象限仪读数和机械重力摆式倾斜传感器输出的数学模型,运用数学推导的方法描述了火炮耳轴倾斜随火炮纵倾的关系,从理论上阐明了用象限仪标定炮耳轴倾斜传感器产生误差的原因及其量值,通过试验进行了验证,并提出了解决方法.对火炮耳轴倾斜的测量方法具有指导意义.     

目标脱靶方位识别的修正方法

针对传统的目标脱靶方位识别的近似方法在弹目交会末端的误差较大,对该识别方法提出修正,得到精确方法,通过算例可以验证修正方法的正确性。修正方法的误差主要来源于数值计算的舍入误差,相对于传统的识别方法没有增大很多的计算复杂度,但精度得到了很大的提高。当在弹目交会末端,采用修正方法来对目标脱靶方位识别能很大程度上为引战配合设计提供更为良好的条件。     

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.