NUCLEAR REDUCTIONS AND MIDDLE EAST STABILITY

The United States faces a series of strategic and policy conundrums as it attempts to promote strategic stability in the Persian Gulf and the wider Middle East. This article examines the relationship between a reduced US nuclear arsenal and strategic stability in the Persian Gulf and the Middle East. It argues that a series of interrelated political and military factors play a much more significant role in regional security and stability than the US strategic arsenal, which has never, with a few extraordinary exceptions, played a direct role in maintaining regional security. The United States has constructed a system of regional stability based on conventional deterrence and defense that has seen it forward base forces at various installations in the region in combination with efforts to arm, train, and equip host-nation militaries. Nuclear weapons have never played a prominent role in this regional system. Evidence presented in this article suggests that there is no compelling reason for the United States to abandon and/or modify the defensive system of conventional deterrence and defense by adding nuclear-backed guarantees to the mix.     

基于MATD的高超声速飞行器反演控制

针对高超声速飞行器弹性体模型,提出了一种基于改进的反正切跟踪微分器(MATD)的鲁棒反演控制器。将控制系统分为高度和速度子系统,采用反演方法设计虚拟控制量和实际控制量。引入MATD对高阶系统虚拟控制量求导,避免了传统反演方法"微分膨胀"的问题。基于MATD设计干扰观测器,对模型不确定项进行精确估计,增强了控制器的鲁棒性。最后,通过实例仿真验证,该控制器对速度和高度指令具有很好的跟踪效果,且具有较强的鲁棒性。     

变质心再入飞行器自抗扰控制器设计(英文)

再入飞行器采用变质心控制不但可以保持较好的气动外形,还町以增大机动能力,但变质心控制较强的非线性和耦合性大大增加了控制系统设计难度,使控制器设计和实施的代价较高。针对这一问题,基于自抗扰控制技术,设计了变质心再入飞行器双通道解耦控制器。通过构造连续光滑扩张状态观测器,不加区分飞行器的各类干扰与耦合,对其统一进行估计:利用非线性状态反馈控制律,并自适应调节控制参数对其进行补偿,实现对飞行器姿态的解耦控制。仿真结果表明:该方法大大降低了对系统模型精度的要求与控制器设计实施代价,对变质心再入飞行器非线性、耦合性以及参数摄动具有较强的鲁棒性。     

基于通信延迟误差补偿的协同导航算法

多自主水下航行器(MAUV)协同导航技术是解决水下定位的重要手段。主从式多AUV协同导航系统利用水声通信方式实现数据共享,但由于声速在水中传播较慢,使得接收到的量测信息具有通信延迟。因此,针对通信延迟问题提出了一种新息重建的状态估计补偿方法,通过对从AUV进行状态递推,获得在有无量测延迟两种情况下的状态误差,将此误差作为重建的新息补偿到状态估计中。仿真结果验证了该方法能够有效地补偿协同导航中由于通信延迟造成的定位误差,提高从AUV的定位精度。     

水中兵器延寿样本的装载可靠度鉴定试验方案

针对延寿样本子样少,按经典GJB899法对装载可靠度鉴定需要较长的试验时间这一实际情况,提出了一种减少试验时间的Bayes方法.该方法通过挖掘延寿前装载失效率信息,确定先验分布,再开展陆上加速装载试验以增加装载信息,并结合实际装载信息制定了装载可靠度鉴定试验新方案.实例计算表明:在确保鉴定效果的前提下,新方法可在较小的延寿样本条件下快速完成装载可靠度鉴定工作,满足水中兵器延寿工程的实际需要.     

African nations as proxies in covert cyber operations

The growth of the African Internet, and services related to the Internet, has been rapid over the last decade. Following this market expansion, a variety of service providers have started to provide access. A fast-growing market puts pressure on the providers to deliver services first and only then seek to secure the networks. Over time, industrialised nations have become more able to detect and trace cyber attacks against their networks. These tracking features are constantly developing and the precision in determining the origin of an attack is increasing. A state-sponsored cyber attacker, such as intelligence agencies and electronic warfare units, will seek to avoid detection, especially when the attacks are politically sensitive intelligence-gathering and intrusion forays into foreign states' networks. One way for the attacker to create a path that links the attacks and the originating country is by actions through a proxy. The less technologically mature developing nations offer an opportunity for cyber aggression due to their lower level of security under the quick expansion of the Internet-based market. Developing countries could be used as proxies, without their knowledge and consent, through the unauthorised usage of these countries' information systems in an attempt to attack a third country by a state-sponsored offensive cyber operation. If the purpose of the cyber attack is to destabilise a targeted society and the attack succeeds, the used proxies are likely to face consequences in their relations with foreign countries, even if the proxy was unaware of the covert activity.     

新型光电装备延伸保修决策方法研究

延伸保修是开展军民融合式装备保障的重要技术手段之一,通过合理选择延伸保修策略,可以在有限的经济条件下较好地完成维修保障任务,提高装备维修保障效益.针对新型光电装备特点,在考虑安全性、任务性和经济性因素的背景下,提出一种由逻辑决断分析法和模糊层次分析法相结合的延伸保修决策方法.通过逻辑决断分析从定性角度选择合理的延伸保修策略,采用模糊层次分析法对逻辑决断得到的结果进行定量补充分析,为类似装备的延伸保修决策提供决策参考.     

基于有限状态机的作战实体模型行为规则可视化建模研究

为提升仿真模型开发效率,降低仿真模型的维护成本,本文从模型规则可视化建模需求入手,提出了基于有限状态机的实体模型行为规则形式化表达模型,并对基于有限状态机的模型规则可视化建模工具框架进行了设计,对模型规则可视化建模的工程实现进行了理论上的探索。     

考虑输入受限的高超声速飞行器预设性能控制

针对考虑输入幅值与速率受限的高超声速飞行器跟踪性能问题,提出基于受限指令滤波器的预设性能控制方案。为了提高系统瞬态和稳态性能,设计预设性能反演控制器,并通过设计新的性能函数使得跟踪误差超调量更小。引入指令滤波器来处理反演控制器设计中难以求导的问题。针对输入受限问题,构造一种受限指令滤波器来约束系统控制律,保证控制输入满足幅值和速率的限制要求,并进行相应的理论证明。另外,考虑系统参数不确定性与外界干扰,采用线性扩张状态观测器进行观测并补偿。基于Lyapunov稳定理论证明系统的所有跟踪误差最终一致有界。通过仿真验证该方法的有效性。     

装备虚拟训练操作过程监控系统的设计

针对在面向操作训练的装备虚拟训练系统开发中遇到的对受训者操作监控的问题,为实现对装备操作过程的详尽描述和对受训者操作逻辑性的监控,提出了一种基于IDEF3的装备操作过程概念建模方法和基于有限状态机、浅层专家知识数据库的操作过程监控系统的设计方案。建立了监控系统的结构框架,并详细介绍了系统三个组成部分的设计方案：浅层专家知识数据库、操作过程状态机和通用操作监控引擎。基于此设计方案的操作过程监控系统已成功的应用于某装备虚拟训练平台,解决了对受训者的操作监控问题,提高了训练效果。