一种由分抗干扰效果推出合成抗干扰效果的方法

提出了一种在外场雷达对抗试验中,由多部具有分抗干扰措施的雷达的抗干扰效果推出某种具有综合性抗干扰措施的雷达的合成抗干扰效果的方法,以在不具备该种雷达的情况下,用多部具有分抗干扰措施的雷达来代替它作为被干扰对象,在外场进行干扰机对其干扰的干扰效果试验检验。     

Periodic review inventory management with contingent use of two freight modes with fixed costs

We study a stochastic inventory model of a firm that periodically orders a product from a make‐to‐order manufacturer. Orders can be shipped by a combination of two freight modes that differ in lead‐times and costs, although orders are not allowed to cross. Placing an order as well as each use of each freight mode has a fixed and a quantity proportional cost. The decision of how to allocate units between the two freight modes utilizes information about demand during the completion of manufacturing. We derive the optimal freight mode allocation policy, and show that the optimal policy for placing orders is not an (s,S) policy in general. We provide tight bounds for the optimal policy that can be calculated by solving single period problems. Our analysis enables insights into the structure of the optimal policy specifying the conditions under which it simplifies to an (s,S) policy. We characterize the best (s,S) policy for our model, and through extensive numerical investigation show that its performance is comparable with the optimal policy in most cases. Our numerical study also sheds light on the benefits of the dual freight model over the single freight models. © 2011 Wiley Periodicals, Inc. Naval Research Logistics, 2011     

基于大涡模拟的气体羽流分层特性数值模拟

采用大涡模拟(LES)对气体羽流分层特性进行数值模拟,分析了基于LES的气体羽流模型、控制方程和数值计算方法,探讨了LES在多组分气体羽流模拟中的应用;以文献[1]中氦气在空气中形成羽流的实验数据为参考,对所建模型进行验证。利用该模型对密闭空间油气泄漏过程进行数值模拟,计算结果表明油气在泄漏发生的240 s之内,不同组分表现出显著不同的分层规律:相对于空气,密度较大的组分聚集在空间下部20%的范围内;密度较小的组分主要分散在空间上部80%的范围内。研究结果为油库油气危险源安全监测与预警、火灾预防与扑救等提供了关键参数参考和工程设计理论依据。     

外辐射源雷达系统中时延估计算法及仿真

时延估计的方法有经典的广义相关法、自适应法、循环平稳法、高阶累积量法、时频分析法等,重点分析了外辐射源雷达系统中用于时延估计的循环平稳法和相关法,并给出了循环平稳法和相关法用于时延估计的仿真,得出了仿真结果。仿真结果表明,对QPSK信号无法用循环平稳的方法来进行时差的获取,用相关法在极低信噪比条件下检测出目标信号,长时间的信号积累是必需的。     

神经网络和DEA方法的炮兵火力毁伤先验评估模型

提出运用BP神经网络理论和数据包络分析(DEA)方法,对炮兵火力毁伤先验评估问题进行研究。利用以往经验数据建立样本集,通过BP神经网络预测模型,对待评估的炮兵火力毁伤计划进行分析,预测其毁伤效益,再建立带有偏好锥结构的DEA评估模型,分析火力计划的可行性和合理性;最后以某部17组炮兵火力毁伤数据进行实例分析。结果表明,该模型能给出科学、明确、可靠的先验评估结果。     

A general model of heterogeneous system lifetimes and conditions for system burn‐in

Burn‐in is a technique to enhance reliability by eliminating weak items from a population of items having heterogeneous lifetimes. System burn‐in can improve system reliability, but the conditions for system burn‐in to be performed after component burn‐in remain a little understood mathematical challenge. To derive such conditions, we first introduce a general model of heterogeneous system lifetimes, in which the component burn‐in information and assembly problems are related to the prediction of system burn‐in. Many existing system burn‐in models become special cases and two important results are identified. First, heterogeneous system lifetimes can be understood naturally as a consequence of heterogeneous component lifetimes and heterogeneous assembly quality. Second, system burn‐in is effective if assembly quality variation in the components and connections which are arranged in series is greater than a threshold, where the threshold depends on the system structure and component failure rates. © 2003 Wiley Periodicals, Inc. Naval Research Logistics 50: 364–380, 2003.     

基于UML的导弹伺服测试系统通用设计方法

分析了导弹伺服测试系统组成及功能,采用UML静态建模技术构建了导弹伺服测试系统设计的需求描述模型,运用动态建模方法建立了系统结构模型和行为模型,并以上述模型为基础,设计了导弹伺服测试系统通用软硬件结构。该方法优化了导弹伺服测试系统共性设计,并创建了特性模型架构和特化接口,有效提高了系统的设计效率和开发质量。     

基于TOPSIS的战区高层反导威胁评估

在分析战区高层反导威胁评估特点的基础上,建立了以来袭TBM发射点、预测落点、射程等为核心的战区高层反导威胁评估模型指标体系并进行了相应的量化,然后利用基于熵值权重确定的TOPSIS理论对模型进行求解。通过实例证明所提出的战区高层反导威胁评估模型和算法的有效性,对研究美军的战区高层反导武器系统具有一定的借鉴意义。     

The Power of the NPT: International Norms and Ukraine's Nuclear Disarmament

ABSTRACT

There is a lingering disagreement among scholars on how the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) affects nonproliferation and disarmament outcomes. Drawing on constructivist scholarship on international norms, this article examines the extent of the NPT's effect in the case of Ukraine's nuclear disarmament. In the wake of the Soviet Union's collapse, Ukraine found itself host to the world's third largest nuclear arsenal. Despite Ukraine's initial commitment to become a non-nuclear state, it proceeded along a difficult path toward NPT accession. Most controversial and directly at odds with the NPT was Ukraine's claim to ownership of its nuclear inheritance as a successor state of the Soviet Union. This article argues that, while much domestic discourse about the fate of these nuclear weapons was embedded in the negotiation of Ukraine's new identity as a sovereign state vis-à-vis Russia and the West, the NPT played an important, structural role by outlining a separate normative space for nuclear weapons and providing the grammar of denuclearization with which Ukraine's decision makers had to grapple.     

航天测试系统大容量数据处理方法研究

在航天测试系统中,经常需要处理大容量数据。讨论了C语言、C++语言、MFC中文件的操作方法。结合Win32 API相关函数,分析了大容量数据文件的读取、解包、分析等处理方法。在VisualC++6.0编程环境下,根据实际需求编写了数据分析处理软件。经过实验验证和实际数据测试,提出的方法可以有效地对大容量数据文件进行分析、处理,且已成功应用于多个航天测试项目,取得了较为理想的分析结果,为相关测试、试验提供了依据。