基于不可信证据源与冲突重分配的证据合成方法

针对D-S证据理论在高冲突下失效的问题,在比较修正原始证据源和重新分配冲突两种方法的基础上,提出一种新的合成规则,新方法用可信度修正证据的同时,把全局冲突分为两部分,并依据"全局冲突在全局分配、局部冲突在局部分配"的原则对冲突进行细化分配。通过仿真分析,并与其他方法比较,新的合成方法能更好地融合冲突证据,收敛速度快,具有较强的抗干扰能力。     

一种改进的D-S冲突证据合成方法

产生反直觉结果是D-S证据理论在融合冲突证据时经常出现的问题,为了解决这一问题,提出一种改进的D-S冲突证据合成方法。利用Pignistic概率距离衡量证据间的冲突;同时,引进证据间相似度、支持度、确定度、决策度以及可信度来共同确定证据的权重,合理地分配冲突在各命题的比例;并对存在冲突的证据进行修正处理;最后,利用统一信度函数模型对证据进行合成。通过算例验证并与其他方法进行对比表明,所研究的方法在处理冲突证据时优于其他方法,鲁棒性和收敛性更好。     

冲突证据组合中的模型修正新方法

针对经典DS组合规则在证据高度冲突情况下的失效问题,提出了一种改进的证据组合方法.通过引入证据间的距离函数获得证据之间的相似度和各个证据的支持度,并由此求得各个证据的归一化可信度.提出了一种改进的证据冲突检验方法,利用可信度加权平均证据对各个证据源进行冲突检验和修正,以消除证据之间的冲突.最后利用DS规则获得合成证据.数值算例表明,该算法能有效地融合高度冲突的证据,提高了证据组合结果的可靠性和合理性.     

一种基于重要性权重的证据合成方法及其应用

针对Dempster方法在合成高度冲突证据时结果与直观结论相悖的问题,提出了一种改进的基于重要性权重的证据合成方法,并将其应用到海上目标的识别。首先,根据证据之间的相似性程度判断证据间是否存在冲突,对于有冲突的情形,由基于P距离的权重分配模型得到各证据的重要性权值;然后,对BPA函数进行修正,采用Dempster规则修正后的BPA函数进行合成;最后,利用雷达和舰船的对应关系,将侦察雷达探测到的目标雷达信号载频、脉宽、重频转化为雷达参数的概率分配,并运用改进的证据合成方法进行了目标识别。仿真计算结果证明:该方法能有效处理冲突证据组合,克服了一票否决问题,减小了识别结果的不确定性,并保留了Dempster方法处理非冲突证据组合的良好特性。     

一种简单有效的处理冲突证据的D-S改进方法*

D-S证据理论在决策级信息融合领域有着广泛的应用,但其在合成冲突证据时会出现与直观结论不符的现象。通过深入分析D-S证据理论合成冲突证据时的失效原因,提出了一种简单有效的改进方法。通过主观权重和客观权重的综合得到不同证据的信任度,以此确定冲突证据及对应的折扣度并对其进行折扣度修正,使合成结果快速向正确类型收敛。仿真结果表明,同已有方法相比,本文方法特别适合具有少数冲突证据的情况,其合成结果更加符合直观判断。     

基于改进D-S证据理论的雷达生存效能

为了综合分析雷达的生存效能,通过调整非关键因素和不确定因素的基本可信度对证据理论中证据合成规则进行了改进,并基于改进D-S证据理论提出了雷达生存效能评估模型.改进后的证据合成规则不仅减小了证据的冲突,而且仍然满足证据的基本可信度之和为1的基本要求,保持Dempster合成规则所具有的可交换性.通过雷达生存效能模型应用的一个实际例子计算表明,证据理论是一种科学的效能评估方法,具有可行性和实用性,改进后的证据合成规则能够较好地分析雷达的生存效能.     

一种修正的冲突证据融合方法

对于冲突证据,D-S证据理论无法使用甚至无法得出正确的结果,进而引发了专家学者的研究。针对该问题,提出了一种新的冲突证据融合方法,建立了多传感器综合可信度的计算模型,根据综合可信度得到多传感器的合成结果,采用D-S证据理论对合成结果进行组合,既解决了高冲突问题,又解决了低冲突问题。最后通过仿真验证了该方法的有效性。     

基于证据理论的多源信息目标识别

目标识别系统中多源传感器信息高度冲突时,利用DS规则直接融合得出的结果不合理,针对该问题,提出了期望证据融合算法。多个证据融合时,根据两证据间的矛盾信息大小确定其相互支持度,将证据支持度矩阵模最大特征值对应的特征向量归一化后得到各证据的权重系数,进而求出期望证据,并用DS规则迭代融合。通过数字仿真对多种方法进行了比较分析,表明期望证据法在传感器信息高度冲突时依然可以得到较为理想的融合结果。     

一种改进的证据组合规则在可靠性评估中的应用

对许多长寿产品进行可靠性评估时,客观实验数据往往难以获取。在试验数据短缺的情况下,就要正确处理专家经验和对相似产品的可靠性认识等不确定信息。为了有效合理地利用这些不确定信息,提出了一种基于Dempster-Shafer证据理论(DST)的可靠性评估方法,针对传统证据理论在处理冲突证据时的不足,用加权证据方法对其组合规则进行了修正。算例实验表明了该方法在有"干扰证据"存在的情况下评估结果的有效性和合理性。     

结合贝叶斯近似变换的冲突证据合成方法

为了解决D-S证据理论在处理冲突证据合成问题中存在的不足,改进了证据合成规则,提出了用该规则和贝叶斯近似变换相结合的证据合成方法。首先分析了封闭世界和开放世界假定中识别框架上认知集合间的转换关系,然后根据证据理论和贝叶斯近似变换的基本知识分析冲突产生的影响,最后根据原证据焦元交集和并集的基数关系改进了合成规则,并进行了实例验证。改进的合成规则能更好的保留原来的信息,而且通过与贝叶斯近似变换的结合减少了焦元的数量,结果表明该方法是一种准确有效的冲突证据合成方法。     

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     

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.     

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.     

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.