调度感知同步数据流建模

对流应用系统进行吞吐量分析需要将周期静态顺序调度建模到数据流图中,吞吐量分析效率依赖于数据流图的规模及建模时间。为了提高吞吐量分析效率,提出基于同构同步数据流图的调度感知同步数据流模型及相应建模方法。通过利用应用模型结构特征及周期静态顺序调度,可减少模型中的任务、边和初始符号数目;可以使用已有分析方法对模型进行吞吐量分析。实验结果表明,所提建模方法优于已有方法,可有效提高吞吐量分析效率。     

Reconsidering minimum deterrence in South Asia: Indian responses to Pakistan’s tactical nuclear weapons

India’s nuclear doctrine and posture has traditionally been shaped by minimum deterrence logic. This logic includes assumptions that possession of only a small retaliatory nuclear force generates sufficient deterrent effect against adversaries, and accordingly that development of limited nuclear warfighting concepts and platforms are unnecessary for national security. The recent emergence of Pakistan’s Nasr tactical nuclear missile platform has generated pressures on Indian minimum deterrence. This article analyzes Indian official and strategic elite responses to the Nasr challenge, including policy recommendations and attendant implications. It argues that India should continue to adhere to minimum deterrence, which serves as the most appropriate concept for Indian nuclear policy and best supports broader foreign and security policy objectives. However, the form through which Indian minimum deterrence is delivered must be rethought in light of this new stage of regional nuclear competition.     

Nuclear weapons,the United States and alliances in Europe and Asia: Toward an institutional perspective

America’s alliances in Europe and East Asia all involve some institutional cooperation on U.S. nuclear weapons policy, planning or employment—from consultative fora in Asia to joint policy and sharing of nuclear warheads in NATO. Such cooperation is often analyzed through the prism of “extended nuclear deterrence,” which focuses on the extension of U.S. security guarantees and their effect on potential adversaries. This article argues that this underplays the importance of institutional factors: Allies have historically addressed a range of objectives through such cooperation, which has helped to catalyze agreements about broader alliance strategy. The varied form such cooperation takes in different alliances also flows from the respective bargaining power of allies and the relative importance of consensus, rather than perceived threats. The article concludes that nuclear weapons cooperation will remain crucial in successful U.S. alliance management, as allies negotiate their relationship with each other in the face of geostrategic change.     

水雾扩散模型仿真

建立水雾红外衰减模型时,通常把水雾空间看作单一均匀整体处理,然而雾滴的扩散现象使水雾的雾滴密度无法保证处处相等,所以仿真结果与实际情况相比普遍存在较大偏差。针对这一问题,基于高斯扩散理论与Mie散射理论,提出了一种新的建模方案。通过将水雾空间划分为多个子空间,并计算每个子空间内水雾消光性能的建模方法,提高建模的准确性。同时结合红外制导导弹来袭的方向变化,计算出不同方向上的水雾消光性能。从仿真结果可以看出,这种建模方式能够很好地克服以往建模方法的缺陷,为探索水雾的精确建模提供了一种新思路。     

Numerical simulation of detonation of an explosive atmosphere of liquefied petroleum gas in a confined space

The detonation of an explosive atmosphere from liquefied petroleum gas disseminated in air in a confined space is studied using numerical modeling with software product ANSYS AUTODYN.     

天基预警系统资源调度问题分析

在介绍天基预警系统作战流程,以及天基预警系统资源和任务的分析和描述的基础上,提出天基预警系统资源调度问题,给出其输入输出结构,并以五元组的形式对该问题进行形式化描述。 关键词：天基预警系统、资源调度、形式化描述     

临近空间高超声速目标上升段拦截需求分析

针对临近空间高超声速目标(NSHT)防御问题,从NSHT的特点出发分析上升段拦截面临的难点,并建立了空基拦截模型,以此为基础分析拦截武器所需的能力并确定其指标,对于拦截系统的建设具有一定的借鉴意义。     

应用改进遗传算法优化天基光学监视平台轨道

针对地球遮挡、地影、太阳光干扰、月光干扰、空间目标相对观测平台的角速度等约束对空间目标可见性的影响问题,基于已编目空间目标双行轨道根数,研究以太阳同步晨昏圆轨道作为观测平台轨道,采用改进多变异位自适应遗传算法对单星观测平台轨道倾角进行优化设计。仿真结果表明,改进的多变异位自适应遗传算法有效地解决了多变异位自适应遗传算法不能保证收敛到所有种群中最优个体的问题,且随机抽取10%左右的目标样本可以达到与采用所有目标相当的性能,计算效率提高约1个量级。     

SPARRING ON THE SUBCONTINENT

South Asian Security and International Nuclear Order: Creating a Robust Indo-Pakistani Nuclear Arms Control Regime, by Mario Esteban Carranza. Ashgate, 2009. 208 pages, $99.95.