基于改进粒子群算法的单预警机动态航迹规划

现代战争的战场环境复杂多变,要求预警机必须在执行任务过程中根据临时获取的战场信息进行实时动态航迹规划,因此动态航迹规划具有更强的实战意义。基于此,首先分析了预警机航迹规划与目前研究的飞行器航迹规划的不同,指出目前研究的静态航迹规划方法不能满足动态规划的实时性要求;其次,对影响预警机动态航迹规划的主要因素进行数学建模后得出代价函数;然后,基于改进粒子群优化算法对其进行动态航迹寻优;最后,通过matlab仿真证明了设计的方法能够自动进行动态航迹规划和评价选优,同时能够满足实时性要求。     

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BP神经网络的UCAV航迹综合评价

针对目前航迹规划过程中评价指标难以统一且指标权重确定过分依赖主观经验的问题,在建立较为完备的UCAV航迹评价指标体系基础上,引入BP神经网络对UCAV备选航迹进行综合评价,从备选航迹的样本数据出发,客观分析航迹的优劣,为决策者提供更加科学合理的参考依据,最后结合仿真算例,验证了该方法的可行性。     

基于变权重搜索策略无人机航路规划算法

通过对A*算法在路径规划中的应用进行研究,提出了一种新的三维航路动态规划方法,通过对搜索策略引入启发式权重系数,利用加权值自适应方法对算法的评价函数进行设计,改善了传统A*算法在大空间中搜索速度低的缺点,提高航迹点搜索效率,同时将无人机的约束条件有效分割到解空间,便于应用于工程实践。基于优化算法规划的最优航路,设计了导引控制律,使无人机很好地跟随规划的路径,同时生成的期望控制指令充分考虑了无人机本身的机动性能以及实时性要求,解决了航迹规划与航迹跟踪之间的问题,最后进行了仿真验证,结果表明:该方法是可行和有效的,有着较高的优化效率;易于实现,工程实用性强。     

区域目标搜索中基于改进RRT的UAV实时航迹规划

在线自主航迹规划是无人机(Unmanned Aerial Vehicles,UAV)执行区域目标搜索任务的有效保证.针对UAV区域搜索中航迹规划的实时性要求,提出了一种固定搜索模式和动态搜索模式相结合的UAV自主航迹规划框架.在快速扩展随机树(RRT)方法的基础上,通过改进随机扩展树的节点选择和引入启发式信息,提出了基于改进RRT的UAV实时搜索航迹规划算法,该算法能够有效降低在线航迹规划的时间代价和扩展节点数.仿真实验结果验证了本文方法的有效性.     

基于DDE改进蝙蝠算法的动态火力分配方法

针对动态火力分配算法耗时长,而传统的蝙蝠算法寻优精度不高等问题,提出了一种基于动态差分改进的蝙蝠算法。该算法首先通过放宽部分约束条件加快生成初始解,然后将动态差分进化算法中的差分变异机制融入到蝙蝠算法中,再利用惩罚函数确保生成的解满足约束条件,最后利用蝙蝠种群进行解的迭代寻优。仿真结果表明,与蝙蝠算法、遗传算法、粒子群算法相比,改进的算法有较高的收敛精度和较快的收敛速率,且更适合应用在较大规模的火力分配问题中。     

多无人机协同任务规划方法

针对多UCAV协同作战的复杂问题,建立了多无人机任务分配模型,模型在任务规划前进行路径预规划,增强规划过程的准确性,提出一种基于整数编码的多种群混合遗传算法对问题求解并进行仿真实验。实验结果表明,该算法增强了搜索的有效性,极大地避免了遗传算法容易陷入未成熟收敛的缺陷,保证了寻优过程的收敛性和任务规划效果的最优化。     

一种可实现TF/TA2的无人飞行器三维航迹规划方法

从规划空间的有效表达着手对无人飞行器三维航迹规划展开研究,基于地形和威胁提出的飞行器航迹规划方法将航迹规划分为学习阶段和查询阶段,环境信息和飞行器的大部分约束条件结合在路线图的构造过程中,航迹搜索在此路线图中进行并最终实现全部约束条件.试验结果显示,该方法可以实时获得实现TF/TA2的三维航迹.     

改进型概率地图航迹规划方法

针对在线航迹规划对时间和内存要求较高,提出一种基于遗传算法的改进型概率地图算法。该方法引入分层规划的思想,在离线航迹规划时,利用遗传算法找到最优初始航迹并建立航迹走廊,以此来缩小概率地图的规划空间。概率地图方法在缩小后的空间中建立概率地图,自由线路数量大大降低,同时使得在线航迹规划搜索范围减少,时间缩短。仿真实例表明,该方案比传统PRM更能满足在线航迹规划的要求。     

一种飞行器在线实时航迹规划算法

针对飞行器在线航迹规划问题展开研究,提出了一种实时航迹搜索算法。该方法将飞行器的运动与航迹搜索结合在一起,可以有效地调节搜索的时间,满足在线实时应用的要求。通过在限定的时间内扩大寻优范围,该算法可以有效地避免不可行区域,并使生成的航迹更加优化。实验结果表明,算法能有效地处理各种航迹约束,实时地生成满意的三维航迹。     

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     

Panjwai: a tale of two COINs in Afghanistan

The US Army has two approaches to counterinsurgency operations in Afghanistan. One is hard, or combat-focused, and the other is soft, or development-focused. This study examines two US Army task forces deployed to Panjwai District, Afghanistan from 2012 to 2013. CTF 4-9 and 1-38 offer a meaningful comparison because they pursued these contrasting approaches among the same population and against the same enemy at the same time and place. The study compares each unit’s approach and finds that neither approach was successful absent the other. The article concludes by recommending further research into combining the approaches at the operational level.     

线性核时频信号表示及其仿真

根据ｃｈｉｒｐ信号在模糊域的特点,本文提出了线性核时频表示方法。这种方法在提高分辨率、消除交叉项以及抑制噪声等方面都具有较高的性能。理论分析和实验结果都证实了这种方法的有效性     

Putin – the masked nemesis of the strategy of ambiguity

Recent events demonstrate the complex and adaptive approach employed by Russia to reassert influence in Europe. The changing face of Russia’s strategy commenced in 2007 when it launched a crippling cyber-attack against Estonia. This was followed by a large Russian conventional attack against Georgia in 2008, occupying two large areas of the nation. 2014 witnessed the Russian annexation of Crimea where in just a week, Russia seized control of Crimea “without firing a shot.” The annexation of Crimea was rapidly followed by a Russian inspired and led subversive war in eastern Ukraine. The common thread among these diverse Russian operations is its use of ambiguity to confound and confuse decision makers in the West.     

Forecasting a Hurricane: Israeli and American Estimations of the Khomeini Revolution

The surprising ‘Arab Spring’ raises the question as to what would enable national intelligence to provide high quality warnings prior to the eruption of popular revolutions. This article uses new sources of evidence to trace and explain Israel's success in comparison to US failure at correctly estimating the course of the Iranian Revolution in 1977–79. In explaining this variance, the article shows that it was mainly the result of the intimate acquaintance of Israel's representatives in Iran with the local language, history and culture, as well as the ability to communicate with locals – tools which the Americans completely lacked.     

关于教师继续教育培训模式的思考

继续教育作为终身教育的重要组成部分和基本形式,对教师的发展成长意义重大。继续教育工作开展十多年来,取得了一定的成绩,但还存在不少问题,如学习动机较为被动,管理认识不到位,教学内容陈旧空泛,教学方法呆板机械等。随着课程改革的不断深入,继续教育必须采取相应的改进措施,树立以人为本,服务至上的观点,教学内容的前瞻性与实用性并重,教学人员进行整合,教学方法灵活多样,评价考核规范科学等,以此激活受训教师内在的学习动机,更大程度地提高继续教育培训的实际效果。     

用DirectShow实现网络视频

目前市场上的网络监控技术一般用昂贵的硬件设备来支撑,投资较大。在深入研究微软的DirectX9.0的基础上,提出如何用DirectShow软件技术和普通的数字摄像头来实现网络视频的监控和实现技术,内容涉及通信协议、视频的编码与解码技术、视频的编码格式和COM组件编程技术等,最终的实验结果令人满意,且费用低廉,技术可靠,为在高速局域网内构建视频监控系统提供有效的技术支持。     

Interpreting the Ribchester Helmet

In 1796 a 13-year-old boy playing on wasteland behind his father’s house in Ribchester, Lancashire discovered an assemblage of over 30 Roman artefacts, including a decorated brass helmet. Although partially corroded the Ribchester helmet is a fine example of a first-century AD cavalry sports helmet. This article considers how the interpretation of the helmet has evolved since its discovery. The multi-faceted iconography of the helmet with its mural crown diadem is that of an elite soldier and is paralleled in other examples of cavalry sports helmets of the Ribchester type. The long-neglected imagery on the helmet bowl is reinterpreted and seen not as a haphazard collection of randomly placed combatants but as a highly structured, symmetrical composition specifically designed to be viewed from different directions.     

Desert insurgency: lessons from the third Tuareg rebellion

This article provides an in-depth examination and analysis of the 2006–2009 Tuareg rebellion in Mali and Niger. It identifies the underlying reasons behind the rebellion, explores contrasting counter-insurgency (COIN) strategies employed by the two governments, and presents some lessons learned. While both COIN approaches ultimately produced similar peace settlements, the article argues that the Malian strategy of reconciliation combined with the selective use of force was far more effective than the Nigerien iron fist approach at limiting the size and scope of the insurgency and producing a more sustainable peace. It concludes by looking at the role of external actors, particularly the United States, and how the failure to internationalize the conflict was actually more beneficial to the local COIN effort, as well as to the longer strategic interests of the United States in the region.