中远距协同空战多目标攻击决策

根据先进战斗机的技术特点和中远距协同空战发展方向,提出一种基于先敌发现、先敌发射、先敌摧毁能力的空战态势分析模型。同时,将并行遗传算法与分布估计算法相结合的并行分布遗传算法应用于上述模型,给出了求解多目标攻击决策问题的算法。最后利用具体算例进行仿真验证。结果表明空战态势分析模型能够较为准确地描述中远距多机协同空战,采用的算法具有较好的可行性和实时性,为中远距多机协同空战的多目标攻击决策提供了新的思路和方法。     

基于变结构的应急航材调度策略

针对应急航材需求的随机性提出了变结构应急航材配送网络的概念,立足于物流运输车辆的优化调度,将现代优化算法引入应急航材的调度中,通过仿真算例的验证可以得出调运路径长度及应急航材需求量与调运时间成正比。     

US strategic preferences in the early twenty-first century

This article investigates how US national security planners have envisioned the emerging strategic environment during the early twenty-first century and evaluates how their perceptions of this strategic environment have changed during these years. This conceptual evolution can be seen in how defense planners define threats, identify defense priorities, and design security strategies. Five key strategic planning documents serve as the basis for this analysis and illustrate significant shifts in how the US government has envisioned its own security requirements as well as the context within which its strategic vision will need to be realized. These planning documents are: (1) Joint Vision 2020, (2) the Bush Administration's 2002 National Security Strategy of the United States, (3) the Obama Administration's 2010 National Security Strategy, (4) US Strategic Defense Guidance entitled Sustaining US Global Leadership: Priorities for 21^st Century Defense, and (5) the US Chairman of the Joint Chiefs of Staff's Capstone Concept for Joint Operations: Joint Force 2020.     

基于GPU的SAR成像层次化并行处理研究

针对SAR成像处理具有的内在并行性,提出了一种基于GPU的SAR成像层次化并行处理方法。首先分析了SAR成像处理过程中信号的并行性,对任务进行了层次化分解与组合,设计了层次化并行的CS成像算法;然后通过CUDA编程将并行成像算法映射到CPU+GPUs系统平台上,实现了层次化并行成像处理;为了检验并行处理效果,采用原始数据进行了SAR成像处理实验。实验结果表明,在几乎没有损失图像质量的情况下,层次化并行处理获得了较高的加速比。     

基于单DSP实现并行扩维离散Hartley变换算法的研究

提出了一种将N点的一维离散Hartley变换(简称DHT)分解成N0×N1点的二维DHT(其中N=N0×N1)和一些运算量很小的附加运算的并行扩维DHT算法,此算法通过减少数据相关性的方法突破了DSP高效求解快速离散Hartley变换(简称FHT)时问题规模受片内内存容量限制问题,降低了编程复杂性,并在TMS320C80的单处理单元上进行了该算法实现方法的研究.结果表明,理论分析和试验结果吻合,该算法适合在单DSP上实现.     

流媒体的RTP传输与QoS管理策略研究

应用RTP协议进行传输和实现QoS管理是当前数据传输方面的热点问题,通过分析RTP协议的结构和原理,提出了一种RTP的传输模型,实现了数据流的RTP传输,同时就RTCP协议(RTP协议的传输控制部分)对QoS的管理策略进行了理论探讨.     

Single machine parallel batch scheduling subject to precedence constraints

We consider the single machine parallel batch scheduling problems to minimize makespan and total completion time, respectively, under precedence relations. The complexities of these two problems are reported as open in the literature. In this paper, we settle these open questions by showing that both problems are strongly NP‐hard, even when the precedence relations are chains. When the processing times of jobs are directly agreeable or inversely agreeable with the precedence relations, there is an O(n²) time algorithm to minimize the makespan. © 2004 Wiley Periodicals, Inc. Naval Research Logistics, 2004     

Enmeshed in insurgency: Britain's protracted retreats from Iraq and Afghanistan

Ten years of counterinsurgency in Iraq and Afghanistan have produced little in Britain's national interest. This article examines the political objectives set in these wars and the reasons why they have proved elusive. The core foreign policy aim was to sustain Britain's position as a great power by assuming responsibility for global order. Alliances with the United States and NATO would be the diplomatic tool for pursuing this aim. These alliances brought obligations, in the shape of agreed common threats. Rogue regimes with weapons of mass destruction and international terrorists harboured in failed states were deemed the primary threats to British security. Military means were therefore used in Iraq and Afghanistan to attack them. Whether Tony Blair's vision of global order ever made sense is debatable, and it attracted scepticism from the outset. The article argues experience in Iraq and Afghanistan showed that a strategy to eliminate terrorism (the WMD threat turned out never to have existed) by expeditionary counterinsurgency could only fail. Therefore the attention lavished on operational-level performance by most studies is misplaced, because no amount of warfighting excellence could make up for strategic incoherence. Finally, the article proposes the more important question arising from the last ten years is why the UK pursued a futile strategy for so long. The difficulties associated with interpreting events, a malfunctioning strategic apparatus, weak political oversight, and bureaucratic self-interest are posited as the most significant explanations.     

球面高斯投影及其变形的闭合公式

将地球视为球体时,高斯投影与横墨卡托投影是同一种投影,因此高斯投影公式可表示为形式紧凑的闭合形式。根据相关定义,以高斯投影的闭合公式为基础,通过一系列数学变换,推导出高斯投影反解公式、经纬线投影方程、投影的长度比及子午线收敛角公式的严格解析式,并借助算例验证了推导结果的可靠性与正确性。与以往根据高斯投影的幂级数公式推得的结果进行了对比分析,结果表明:所推导出的公式逻辑上更严密、形式上更紧凑,既丰富了高斯投影理论,又完善了地图投影数学基础。     

射频隐身反隐身E&V系统的设计与实现

针对战机射频隐身性能很难评估的现实问题,提出一种射频隐身反隐身实验与验证半实物仿真系统的设计与实现方法。该系统不仅能对战机的射频隐身性能进行验证,同时还可以对飞机的隐身波形、辐射策略等设计提供理论依据和实验支撑。在分析辐射信号模型以及截获模型的基础上,详细介绍了该系统的各功能组成和结构框图。该系统可以开展对于射频隐身的作战需求、管控模型、使用准则等方面的定量研究,对于提高战机的生存能力、突防能力和作战能力具有重要的意义。