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201.
为了解决副面遮挡导致小口径卡氏天线(D=293mm)副瓣电平恶化这一难题,本文提出了一种优化赋形方法。采用优化口径场分布,对主、副面形状进行赋形设计。用该法设计了一种八毫米低副瓣卡氏天线(sll1≤-25dB),实验结果与理论计算十分吻合。  相似文献   
202.
本文根据作者近年来研制交互式管理信息系统(MIS)生成工具的实践,阐述了一个人机界面友好的交互式MIS生成工具的设计与实现。这个工具本身是交互式系统,生成的MIS也是交互式系统。它是根据交互式系统的一般结构,采用控制结构上悬挂模板的方式来构造和组装(MIS)软件产品。  相似文献   
203.
We study the problem of recovering a production plan after a disruption, where the disruption may be caused by incidents such as power failure, market change, machine breakdown, supply shortage, worker no‐show, and others. The new recovery plan we seek after has to not only suit the changed environment brought about by the disruption, but also be close to the initial plan so as not to cause too much customer unsatisfaction or inconvenience for current‐stage and downstream operations. For the general‐cost case, we propose a dynamic programming method for the problem. For the convex‐cost case, a general problem which involves both cost and demand disruptions can be solved by considering the cost disruption first and then the demand disruption. We find that a pure demand disruption is easy to handle; and for a pure cost disruption, we propose a greedy method which is provably efficient. Our computational studies also reveal insights that will be helpful to managing disruptions in production planning. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2005.  相似文献   
204.
针对公安消防局防火处的工作现状,以信息技术为基础,结合软件工程中的快速原型法及结构化分析方法,论述了开发防火处MIS过程中的主要技术特点,并简要阐述了关键技术的实现方法。  相似文献   
205.
We present two frameworks for designing random search methods for discrete simulation optimization. One of our frameworks is very broad (in that it includes many random search methods), whereas the other one considers a special class of random search methods called point‐based methods, that move iteratively between points within the feasible region. Our frameworks involve averaging, in that all decisions that require estimates of the objective function values at various feasible solutions are based on the averages of all observations collected at these solutions so far. Also, the methods are adaptive in that they can use information gathered in previous iterations to decide how simulation effort is expended in the current iteration. We show that the methods within our frameworks are almost surely globally convergent under mild conditions. Thus, the generality of our frameworks and associated convergence guarantees makes the frameworks useful to algorithm developers wishing to design efficient and rigorous procedures for simulation optimization. We also present two variants of the simulated annealing (SA) algorithm and provide their convergence analysis as example application of our point‐based framework. Finally, we provide numerical results that demonstrate the empirical effectiveness of averaging and adaptivity in the context of SA. © 2012 Wiley Periodicals, Inc. Naval Research Logistics, 2012  相似文献   
206.
随着寄存器传输级甚至行为级的硬件描述语言应用越来越广泛,基于一阶逻辑的可满足性模理论(Satisfiability Modulo Theories,SMT)逐渐替代布尔可满足性(Boolean Satisfiability,SAT),在VLSI形式化验证领域具有更加重要的应用价值。而极小不可满足子式能够帮助EDA工具迅速定位硬件中的逻辑错误。针对极小SMT不可满足子式的求解问题,采用深度优先搜索与增量式求解策略,提出了深度优先搜索的极小SMT不可满足子式求解算法。与目前最优的宽度优先搜索算法对比实验表明:该算法能够有效地求解极小不可满足子式,随着公式的规模逐渐增大时,深度优先搜索算法优于宽度优先搜索算法。  相似文献   
207.
多比特信息分布式检测优化研究   总被引:1,自引:0,他引:1       下载免费PDF全文
本文拓展了通常意义下多传感器组网分布式检测模型,允许各传感器向融合中心传输多比特信息。给出了Kullback分辨率意义下,确定最优多比特信息的方法,以利于改善系统检测性能。数值结果表明,多比特信息分布式检测方案是可行的。  相似文献   
208.
在原子轨道线性组合方法中引进规范变换,推导出在外加恒定磁场下分子中的电子环流表达式,应用该理论导出了分子磁化率的一般公式,并对C60和C70分子中π电子的磁化率进行了计算。  相似文献   
209.
The issue that this paper tackles is the assessment of the relative security benefits that Cyprus and Greece derive in the context of their cooperation on defence matters. This form of cooperation, known as the ‘Integrated Defence Space Doctrine’, aims at defending their interests in the Aegean Sea and the broader East Mediterranean theatre. The paper relies heavily on earlier research on this topic, which deals with the Greek–Cypriot alliance facing an arms race against Turkey, and uses a coefficient especially designed to assess the optimal levels of security and the associated defence expenditure of the two allies. A comparison of the relative security coefficient values for the two allies suggests that the security benefit that Greece derives thanks to its alliance with Cyprus exceeds the corresponding Cypriot benefit by far. Given the importance assigned to human resources by this index, in conjunction with the demographic problems of Greece, this conclusion justifies the recent Greek defence policy revision, emphasizing quality, capital equipment and flexibility of forces. This revision aims at satisfying the security requirements of the alliance and the increasing demands of an arms race against Turkey.  相似文献   
210.

This paper examines the trade and military relationship between two countries which have a common military enemy. The paper explains how the former two countries, which are military allies and trading partners, share the burden of defence against the third country. It demonstrates how the defence production of a country may hurt its ally because the latter country's terms of trade can be deteriorated. Whether or not a smaller ally spends less on defence is analyzed. Also analyzed is the effects of the reactions of the enemy country on the trade between the two allies and their welfare.  相似文献   
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