Urban gangs evolving as criminal Netwar actors

The nature of conflict and crime is changing. Technology allows groups to spread their influence without regard to geographic limitations. A shift from hierarchies to network organizational forms is also occurring. As a consequence non‐state actors can extend their influence to gain social, political or economic power and challenge state institutions. This article examines the potential for gangs, transnational criminals and terrorists to embrace network forms and utilize technology to wage netwar. Factors which influence ‘third generation’ gang organization (politicization, internationalization and sophistication) are described to illustrate how a net‐based threat can mature. A move toward network organization within transnational criminal organizations and terrorist groups demonstrating the potential for these classic criminal entities to emerge as netwar actors is also reviewed. Finally, the need for state institutions such as the police and military to develop networked responses to combat networked threats is stated.     

多平台雷达有源干扰资源分配算法

根据现代干扰机特点,建立"多对多"雷达有源干扰资源分配数学模型,结合分配算法的具体应用环境,提出了基于多Agent分布协同拍卖的雷达干扰资源分配算法,实例表明该方法可行。     

时变环境下基于加速寿命试验的产品故障预测方法

针对传统可靠性模型及分析方法无法分析产品在时变环境下可靠性的缺陷,提出了时变环境应力下产品可靠性预测方法.引入比例风险模型描述产品可靠性与工作环境因素的关系,结合加速寿命试验数据,利用极大似然估计确定基准失效率函数及各环境因素协变量回归系数.在假设产品工作环境应力转换时间确定的情况下,建立了时变环境下可靠度分析模型.实例验证了该方法的有效性.     

基于仿真的竞争失效产品步降加速寿命试验优化设计

针对竞争失效产品加速寿命试验存在试验时间长、费用高、效率低的问题,提出了一种基于Monte-Carlo仿真的竞争失效产品步降加速寿命试验优化设计方法.采用Monte-Carlo对步降加速寿命试验进行仿真模拟,以正常使用应力下的p阶分位寿命渐进方差估计最小为目标,以各试验应力水平及对应应力下的试验截尾数作为设计变量,采用MIE理论进行统计分析,建立了基于仿真的竞争失效产品步降加速寿命试验优化设计模型.最后,通过实例分析表明:该方法具有可行性、有效性.     

改进型Voronoi图和动态权值A*算法的无人机航迹规划

针对实际作战环境中的不同威胁等级和不同威胁实体的威胁源,提出了改进型的Voronoi图,并建立了基于改进型Voronoi图的航迹规划空间;基于A*算法的估价函数在不同阶段对指标的敏感度不同,在传统的启发式A*搜索算法基础上提出了动态权值A*搜索算法,提高了航迹搜索的效率,实现了航迹搜索过程快速性和准确性的结合。最后通过Matlab仿真计算出由动态权值A*算法得到的最优航迹,并进行了航迹的平滑处理,仿真表明了该方法的可行性。     

基于动力学与运动学的四轮全向移动机器人轨迹跟踪控制

建立了四轮全向移动机器人的运动学模型和动力学模型,并分析了四轮全向移动机器人执行器的机械特性。在此基础上,利用反馈控制设计了四轮全向移动机器人的运动学控制器,利用逆动力学补偿控制设计了四轮全向移动机器人的动力学控制器,实现了基于动力学与运动学的四轮全向移动机器人轨迹跟踪控制系统设计。最后,利用Matlab/Simulink完成了基于动力学与运动学的四轮全向移动机器人轨迹跟踪控制仿真实验,实验结果验证了该轨迹跟踪控制方法的有效性。     

PUBLIC SAFETY AND THE MORAL DILEMMA IN THE DEFENSE AGAINST TERROR

The economic theory of defense has traditionally described public safety as achieved through investments that deter adversaries. Deterrence is, however, ineffective and pre‐emptive defense is required when a population of intended victims confronts supreme‐value suicide terror. A moral dilemma then arises, since pre‐emption may impose collective punishment, while in the absence of pre‐emption the population of intended victims is exposed to acts of terror. We consider how a population of intended terror victims confronts the moral dilemma, and compare the threatened population's response with the public‐safety recommendations of external judges who are not personally affected by the threat of terror.     

Ridge regression analysis of the defence‐growth tradeoff in the United States

An examination of past analyses suggests that today's sailors may be less responsive to compensation changes than previous generations. Such a change could make recruiting and retaining high‐quality sailors more difficult. However, variation in researchers' decisions over time may simply have created the appearance of such a change. Our results suggest there is little variation in the pay elasticity over time. In contrast, the different reduced‐form models we use to measure this relationship can explain most of the variation in the literature. Therefore, the evidence suggests that while sailors may have changed over time, their response to compensation has not.     

MODELS OF MILITARY EXPENDITURE AND GROWTH: A CRITICAL REVIEW

This paper reviews some of the theoretical and econometric issues involved in estimating growth models that include military spending. While the mainstream growth literature has not found military expenditure to be a significant determinant of growth, much of the defence economics literature has found significant effects. The paper argues that this is largely the product of the particular specification, the Feder–Ram model, that has been used in the defence economics literature but not in the mainstream literature. The paper critically evaluates this model, detailing its problems and limitations and suggests that it should be avoided. It also critically evaluates two alternative theoretical approaches, the Augmented Solow and the Barro models, suggesting that they provide a more promising avenue for future research. It concludes with some general comments about modelling the links between military expenditure and growth.