排序方式: 共有79条查询结果,搜索用时 13 毫秒
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传统的关联成像方法未考虑复杂扩展目标的结构信息,在高分辨成像时的应用受到限制,为此提出一种自适应结构配对稀疏贝叶斯学习方法。该方法在稀疏贝叶斯学习的框架内针对扩展目标建立一种结构配对层次化高斯先验模型,然后采用变分贝叶斯期望-最大化算法交替进行目标重构和参数优化。该方法将某一信号分量的重构与周围信号分量联系起来,并能在迭代过程中自适应地调整表征各信号分量相关性的参数。实验结果表明,该方法针对扩展目标可以有效地进行高分辨成像。 相似文献
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Peter J. Phillips 《Defence and Peace Economics》2013,24(6):403-414
Security measures are said to increase the price of terrorism. This price has not been hitherto defined in an economically meaningful way. This paper provides a precise definition by treating the terrorists’ resource endowment as a parcel of contingent claims to political influence with a price equal to the summed value of those contingent claims in potential states of the world. Equipped with this definition, an equilibrium model of the price of terrorism is deployed. Important insights are gained into the effect of terrorists’ risk aversion at the level of the price of terrorism in different states of the world and the theoretical conclusion is reached that higher security is associated with a lower price of terrorism rather than a higher price. The implications for policy are discussed. 相似文献
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Matthew Ford 《Small Wars & Insurgencies》2014,25(3):495-500
British attitudes towards military intervention following the campaigns in Iraq and Afghanistan have undergone what appears to be considerable change. Parliament has voted against the use of Britain's armed forces in Syria and the public are unenthused by overseas engagement. Conscious of the costs and the challenges posed by the use of British military power the government has been busy revamping the way it approaches crises overseas. The result is a set of policies that apparently heralds a new direction in foreign policy. This new direction is encapsulated in the Building Stability Overseas Strategy (BSOS) and the more recent International Defence Engagement Strategy (IDES). Both BSOS and IDES set out the basis for avoiding major deployments to overseas conflict and instead refocuses effort on defence diplomacy, working with and through overseas governments and partners, early warning, pre-conflict prevention and post-conflict reconstruction. Developing a number of themes that reach from across the Cold War to more contemporary discussions of British strategy, the goal of this special edition is to take into account a number of perspectives that place BSOS and IDES in their historical and strategic context. These papers suggest that using defence diplomacy is and will remain an extremely imprecise lever that needs to be carefully managed if it is to remain a democratically accountable tool of foreign policy. 相似文献
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舰艇编队的区域防空作战是一个复杂问题.具有体系特性的战略层规划一直是其中的重点和难点.探索性分析正是适宜解决这一难题的方法论,它可以通过高层次模型的定量探索,在深入细节之前对问题有个广度的了解.依照探索性分析的思想,从宏观层次描述舰艇编队区域防空问题;基于所设计的时间片影响图分析建模软件工具EASim,建立了该问题的高... 相似文献
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研究了硼砂对磷酸镁水泥凝结时间与抗压强度的影响,分析了硼砂对水泥性能影响的微观作用机制.研究发现:随着硼砂对MgO质量分数增加,磷酸镁水泥凝结时间延长,其早期抗压强度迅速降低,后期抗压强度所受影响相对较小;磷酸镁水泥应用于快速修补及抢修抢建时,硼砂质量为氧化镁质量的5%~10%为宜;硼砂对磷酸镁水泥水化产物的早期生成量... 相似文献
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拟制作战计划的关键是生成作战行动序列.考虑作战行动过程中的不确定性以及激烈对抗性,以影响网络分析作战行动和战场态势之间的相互影响,用不完全信息博弈分析敌对双方之间的对抗,建立了基于影响网络和不完全信息多阶段博弈的作战行动序列模型,并给出了求解方法.通过计算实例说明了模型及其求解方法.结果显示该模型生成的COA更适应于对抗环境. 相似文献
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根据装甲装备在试验和使用中人因故障发生的原因,将人因故障影响因素分为设计因素、维修因素、使用因素、人体机能因素、人机界面因素和环境因素6类,采用灰色关联分析法对其进行辨识分析,发现造成装甲装备人因故障率从高到低的因素依次为:维修因素、使用因素、人机界面因素、设计因素、环境因素和人体机能因素,该研究结果可为装甲装备综合管理和设计提供理论依据。 相似文献