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241.
网络中心战是未来战争的主要作战样式,网络复杂性也是需要研究的重要问题之一.提出基于复杂网络的防空反导系统网络模型,并对网络模型的拓扑结构、统计特征和中心度进行了研究.针对防空反导体系结构问题,复杂网络理论是一种有效揭示网络内部特性的分析工具,对于网络模型的建立和优化具有很好的理论指导意义. 相似文献
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多信道所带来的MCC(Multiple Channel Coordination)问题是影响多信道系统性能的重要因素。文章针对无线Ad Hoc网络,提出了一种多信道协同MAC(Media Access Control)协议。该协议扩展了协同通信的概念,邻节点不再转发发送节点的数据,而是帮助发送节点发现和避免多信道中的MCC问题。文章还对经典二维Markov模型进行了改进,加入了多信道和协同机制,对所提协议进行了建模,分析了协同机制对系统性能的影响,并推导出了吞吐量性能和时延性能的表达式。仿真结果表明,采用协同机制可以有效解决MCC问题,文章中所提协议相对传统多信道MAC协议可以大大提高吞吐量和时延性能。 相似文献
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Mustapha Bouhtou Alexander Grigoriev Stan van Hoesel Anton F. van der Kraaij Frits C.R. Spieksma Marc Uetz 《海军后勤学研究》2007,54(4):411-420
We consider a pricing problem in directed, uncapacitated networks. Tariffs must be defined by an operator, the leader, for a subset of m arcs, the tariff arcs. Costs of all other arcs in the network are assumed to be given. There are n clients, the followers, and after the tariffs have been determined, the clients route their demands independent of each other on paths with minimal total cost. The problem is to find tariffs that maximize the operator's revenue. Motivated by applications in telecommunication networks, we consider a restricted version of this problem, assuming that each client utilizes at most one of the operator's tariff arcs. The problem is equivalent to pricing bridges that clients can use in order to cross a river. We prove that this problem is APX‐hard. Moreover, we analyze the effect of uniform pricing, proving that it yields both an m approximation and a (1 + lnD)‐approximation. Here, D is upper bounded by the total demand of all clients. In addition, we consider the problem under the additional restriction that the operator must not reject any of the clients. We prove that this problem does not admit approximation algorithms with any reasonable performance guarantee, unless P = NP, and we prove the existence of an n‐approximation algorithm. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007 相似文献
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Designing Code Division Multiple Access networks includes determining optimal locations of radio towers and assigning customer markets to the towers. In this paper, we describe a deterministic model for tower location and a stochastic model to optimize revenue given a set of constructed towers. We integrate these models in a stochastic integer programming problem with simple recourse that optimizes the location of towers under demand uncertainty. We develop algorithms using Benders' reformulation, and we provide computational results. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2007 相似文献
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ABSTRACTAssistance of local-national partners is necessary to the USA in order to protect its national security interests throughout the world. These partners, typically individuals who support USA diplomats, service members, and non-governmental organizations (NGOs) in non-combatant roles, form USA soft networks. Due to the nature of their work, many of these individuals associated with the policy and actions of the USA become vulnerable to violent threats from adversaries. In fact, adversaries have grasped that attacking USA soft networks is a logical approach for enemies fighting from positions of weakness. As a result, examination of other domains may yield best practices that build resiliency in USA soft networks, thereby cementing national security interests. Further, agency theory illuminates critical principles in the relationships between local-national partners and field practitioners, and informs policy development efforts as a result. 相似文献