Optimal patrol to uncover threats in time when detection is imperfect

Consider a patrol problem, where a patroller traverses a graph through edges to detect potential attacks at nodes. An attack takes a random amount of time to complete. The patroller takes one time unit to move to and inspect an adjacent node, and will detect an ongoing attack with some probability. If an attack completes before it is detected, a cost is incurred. The attack time distribution, the cost due to a successful attack, and the detection probability all depend on the attack node. The patroller seeks a patrol policy that minimizes the expected cost incurred when, and if, an attack eventually happens. We consider two cases. A random attacker chooses where to attack according to predetermined probabilities, while a strategic attacker chooses where to attack to incur the maximal expected cost. In each case, computing the optimal solution, although possible, quickly becomes intractable for problems of practical sizes. Our main contribution is to develop efficient index policies—based on Lagrangian relaxation methodology, and also on approximate dynamic programming—which typically achieve within 1% of optimality with computation time orders of magnitude less than what is required to compute the optimal policy for problems of practical sizes. © 2014 Wiley Periodicals, Inc. Naval Research Logistics, 61: 557–576, 2014     

盖板式陶瓷热防护系统的传热性能优化

针对高超声速飞行器对盖板式陶瓷热防护系统的迫切需求,建立了热防护系统结构瞬态传热模型;并研究了防隔热层的物性参数,厚度尺寸,相变层的种类、位置等因素对热防护系统结构传热性能的影响。结果表明,隔热层物性参数及厚度尺寸对热防护系统结构传热性能具有决定性影响,而防热层的物性参数及厚度尺寸几乎不产生影响。相变材料的引入能够明显改善热防护系统结构的传热性能。调整和优化相变层位置是改善热防护系统结构传热性能、降低结构厚度的一个有效途径。隔热层厚度的优化结果可为热防护系统结构设计提供一定的参考和依据。     

基于非入侵式负荷小区用电设备监测技术

加强用电设备能耗的监测是我国提高电能利用率、实现能源可持续发展、建设节约型社会的重要手段。通过对国内外用电设备监测技术和方法的研究,以及对几种常用用电设备识别方式、原理和优缺点的比较,提出了一种基于非入侵式负荷的谐波电流面积监测技术。采用该技术对小区用电设备进行Matlab仿真,并对仿真结果进行分析和验证。结果证明该技术能提高用电设备的识别精度和能耗监测效率,对减少小区经济损失、提高电力系统稳定性、实现能源可持续发展具有一定的意义。     

指挥信息系统安全防护系统视图

作为指挥信息系统安全可控运行的重要保障,网络安全防护体系目前存在着整体轮廓不清、顶层设计力度不够等问题。研究网络安全防护体系结构,可以增强安全体系综合集成,提高组件间的互操作性,有效解决网络安全防护的顶层设计问题。通过分析军事信息系统体系结构框架中系统视图模型的内容和相互逻辑关系,描述了支持网络防御作战的系统、系统功能及其相互关系,建立了系统视图的几种典型模型,为体系化建设网络安全防护体系提供了理论依据。     

可溶纤维防火门芯板研制及应用前景

分析了目前国内外防火门芯板技术和生产现状,提出应研发可溶性纤维门芯板以满足环保和防护等级的需要。介绍了研发可溶性纤维门芯板的技术路线和技术关键,预测了可溶纤维防火门芯板的应用前景。     

营区综合通信网防雷系统的设计与实现

针对雷电的危害形式和途径,在分析了雷电入侵主要途径的基础上,进一步研究了营区综合通信网预防雷击、进行防雷保护和减少雷电危害的机理,给出了营区综合通信网具体的防雷电措施的实施方案。     

飞行器涂层防热选材、设计与应用

就防热材料选材、设计,主要是涂层设计原理和设计过程中需要考虑的一些问题浅谈了一些体会,对变密度非稳态的、有机/无机杂化防热涂层材料的热导率计算等参数辨识方法原理作了初步探讨,还介绍了几种热防护涂层(TPC)的性能、应用情况和防热效果.     

飞控设备抗强电磁脉冲方法研究

强电磁脉冲可引起空间飞行器的控制设备发生瞬时或永久故障,从而导致飞行失控。针对强电磁脉冲环境下飞控设备的防护问题,首先分析了强电磁脉冲对飞控设备的损伤效应,其次探讨了相关的防护方法,并给出了屏蔽效能和整机防护试验验证的测试结果,为提高飞控设备抗强电磁脉冲能力建立基础。     

Force protection and society

Wars have long been fought with a firm focus upon armies' domestic contexts. These socio-political foundations have underpinned decisions regarding embarking upon war as well the conduct of war itself. Of particular importance among liberal democracies is the emphasis which is now placed upon force protection; broadly conceived as the range of measures employed to ensure the protection of servicemen and women on operations. Decisions surrounding protective equipment, deployed locations and wartime activities all face detailed scrutiny in contemporary operating environments. The attitudes of the government, the military and the civilian population combine to create a complex and dynamic backdrop of harmony and tension to this most sensitive characteristic of modern wars.     

电晕放电若干特性的实验研究

为研究空中带高压物体的电晕放电辐射信号特征,采用组建的静电放电测试系统对电晕电流及其辐射信号进行了实验研究。实验表明：电晕放电脉冲波形具有明显的极性效应。负极性下先发生电晕放电,且电流波形的上升时间小于正电晕电流;电晕放电信号波形前沿陡峭,上升时间从几个ns到二十几个ns;电晕放电辐射信号的频谱成钟型连续谱,其频率范围主要集中在20～100MHz之间;极性不同,电晕放电辐射信号波形不同,并且正电晕信号幅值高于负电晕信号幅值。