The Fallujah awakening: a case study in counter-insurgency

The successful pacification of Fallujah in 2007 during the Anbar Awakening movement was due to the coordinated efforts of US and Iraqi forces to physically and psychologically separate the people from the insurgency. Efforts along security, political, and development lines along with a robust tribal effort eliminated the armed insurgency and set the basis for victory in the area. But a synchronized delivery of these resources was insufficient to defeat the insurgency by itself absent the population's decision to turn against the insurgents. This process began to occur in 2006 and was successfully capitalized upon by Coalition Forces in Fallujah in 2007.     

Research communication

A UK House of Commons Defence Committee (HCDC) Report on the Gulf War recommended that the UK should be self‐sufficient in supporting its Armed Forces in times of crisis and not even rely on its Allies. This recommendation is at odds with UK Government policy which rejects any formal strategy of support for the defence industrial base preferring international open competition as its procurement philosophy. This paper examines the various factors ranging from the supply of raw materials, production capacity, stockpiling, international joint ventures, and competition through to the effects on the technological update of weapon systems resulting from this philosophy. It draws conclusions supporting the HCDC recommendation and calls for joint MOD‐Industry action to address the issues involved and thereby reduce the risks to the Defence of the Realm.     

运载火箭姿控系统三通道Simulink建模与仿真分析

以某运载火箭为例,介绍了将姿控系统数学模型转化为Simulink三通道仿真模型的方法和过程;在仿真过程中涉及到时变系数的瞬时时间固化法,分析由此引起的计算数据局部振荡,并提出解决办法;分析了用Simulink为该大型系统建模时所遇到的代数循环问题,并加以解决。     

雷电浪涌对直流电源冲击效应的实验研究

直流电源是雷电进入电子系统的主要途径。为了研究雷电浪涌对直流电源的冲击效应 ,进行了雷电浪涌对直流电源的注入实验 ,发现雷电浪涌对直流电源有很大的干扰和破坏作用 ,并在实验基础上 ,提出了有效的防护措施     

中低速磁浮列车传感器防浪涌设计及改进

为提高磁浮列车悬浮传感器的可靠性,分析在雷击、电源干扰等工况条件下的浪涌产生机理,确定浪涌冲击试验的内容,从通流量的角度说明已有防浪涌电路设计的可行性,并指出其在高温环境下在可靠性方面存在的不足。分别从降压和分流的角度进行分析,通过在原有电路中并接大容量电容的方式降低浪涌对敏感器件的冲击,从而提高传感器电源的抗浪涌冲击能力。     

基于系统辨识的雷击浪涌注入效应仿真

为探索系统辨识方法在电磁脉冲注入效应仿真领域的适用性，使用三端稳压电源进行雷击浪涌注入实验，分别采集注入的雷击浪涌电压和三端稳压电源的响应电压。对采集的数据运用dh系列小波降噪，进行去除趋势项预处理。选用ARX模型，利用最小二乘法进行参数辨识。根据所得模型预测在不同浪涌电压下三端稳压电源的响应电压，并与实际电压进行对比。计算结果表明，基于系统辨识的方法得到了满意的能量耦合模型，较好的预测了三端稳压电源的响应电压。     

气浮箱型结构纵荡运动水动力系数解析研究

基于二维微幅波理论,采用特征函数展开和匹配渐进法建立了气浮箱型结构纵荡运动的解析解,将Matlab程序计算结果与MOSES数值模拟结果进行了对比分析,验证了程序的合理性;进而对不同吃水、不同水深下结构纵荡运动的附加质量系数和阻尼系数的幅频变化规律进行了研究。结果表明:由于未考虑结构内部气体的可压缩性,数值模拟结果大于程序计算结果,MOSES计算结果偏安全;在一定频率区段上,吃水的增加对结构附加质量系数和阻尼系数有显著影响;随着水深吃水比的增加,结构的附加质量系数和阻尼系数呈增大趋势,只有在圆频率为0.65~0.9 rad/s时呈减小趋势,而阻尼系数则呈增大趋势。     

无感电阻网络分流器研制与性能分析

分析了雷电浪涌发生器短路电流波形的特点 ,研制了无感电阻网络分流器 ,实验证明该分流器测试结果的重复性和测试不同量值的雷电脉冲电流时的线性度 ,均符合国家标准GB/T176 2 6 5 - 1999和国际电工委员会标准IEC6 10 0 0 - 4- 5的要求。