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1.
通信网中链路重要性的评价方法   总被引:17,自引:0,他引:17       下载免费PDF全文
本文提出了一种通信网链路重要性的评价方法,该方法可以评价全网范围内的链路重要性.最重要的链路是将其进行边收缩操作后,得到的图的生成树数目最多.通过比较生成树的数目,我们可以判断通信网中任意两条链路的相对重要性.基于生成树数目的边收缩方法反映了某条链路处于正常工作时,对整个通信网的贡献大小.实验结果和理论分析均证明了该方法的有效性和可行性.  相似文献   

2.
无线网络中节点重要性的研究   总被引:1,自引:0,他引:1       下载免费PDF全文
张品  陈磊  姜亚光 《电子器件》2011,34(4):395-397
提出了一种判断无线网络中节点重要性的新方法——节点插入法,并给出了归一化表达式,认为最重要的节点是在 其相关链路上插入一个新节点后,使图的生成树增加最多.该方法可以判断全网范围内节点的重要性,并比较任意两个节点 的相对重要性,理论分析和仿真结果表明,该方法对新加入节点的位置评估要优于其它算法.  相似文献   

3.
程猛  吴永明 《通信技术》2010,43(8):205-207
准确地评估通信网中节点的重要性,对于通信网的设计、维护管理以及提高整个通信网的可靠性都有重要作用。现有的一些评估方法通常只是考虑单一的影响因素,其评估结果不准确。提出一种基于自组织神经网络的通信网节点重要性评估模型,将通信网中节点的度、节点的网络凝聚度、节点对通信网生成树的影响程度和节点对通信网可靠性的影响程度作为节点重要性的评价指标,对通信网中的节点进行重要性等级的划分。实验结果表明该模型能够全面地评估节点的重要性。  相似文献   

4.
孙伟  罗俊海  肖志辉 《电信科学》2011,27(12):90-96
在数据交换网络中,颜色树是一种通过节点不相交的多路径路由数据报文的有效方法。这种方法中组建两棵以某一节点为根节点的颜色树,即Red树和Blue树,网络中各节点到根节点的路径是节点不相交的。本文在分析和研究SimCT算法的基础上,提出了一种基于颜色树的多播树生成方法及单节点/链路故障的多播通信恢复方案。该方法根据SimCT算法构造的颜色树来组建一棵多播转发树,在多播树中单节点或单链路故障后,故障检测节点本地执行故障恢复方案,将受影响的故障节点的下游子树重新连接到多播树。仿真实验表明,本文所提出的多播树生成方案相比现有方案可以减少网络资源的浪费,并且故障恢复后的代价与原多播通信树相当。  相似文献   

5.
链路重要性对于确定链路维修顺序、链路防护级别以及网络拓扑优化具有重要意义。从链路正常工作的角度出发,提出基于图论的边收缩方法,认为网络化信息系统网络拓扑模型的某条边收缩后,得到的图对应的生成树数目越多,则该边对应的链路对于网络化信息系统的重要程度越高。运用该方法评价了某网络化信息系统(局部)各链路的重要性,评价结果与实际吻合,证明了该方法的可行性。  相似文献   

6.
郝婕宇  杨宗霄 《通信技术》2010,43(1):200-202
全局最短路径是组合优化的经典问题之一。求解最小Steiner树的可视化试验成功的在给定节点中间生成了Steiner点,但当给定节点数目增多且呈不规则分布时,试验方法形成薄膜路径困难并且不稳定。针对试验的不足,文中构建了Exp-Geo算法。在给定点数目增多时,采用该算法能够在给定节点之间生成Steiner点,得到全局最短路径,弥补试验的不足。经过多次试验、计算、对比分析,证明该算法能在多点系统中找到系统全局最短路径,为可视化试验的推广奠定了基础。  相似文献   

7.
链路重要性对于确定链路维修顺序、链路防护级别以及网络拓扑优化具有重要意义.从链路正常工作的角度出发,提出基于图论的边收缩方法,认为网络化信息系统网络拓扑模型的某条边收缩后,得到的图对应的生成树数目越多,则该边对应的链路对于网络化信息系统的重要程度越高.运用该方法评价了某网络化信息系统(局部)各链路的重要性,评价结果与实际吻合,证明了该方法的可行性.  相似文献   

8.
借助图论中最短路径和最小生成树的原理,在无线传感器网络中构建若干棵以Sink节点为根的最短路径源路由树。与最小生成树相比,最短路径树能保证路径上大部分节点找到节点间RSSI较强的通讯路径并以较少的跳数把数据传输给Sink节点,而最小生成树中的节点则需较多跳数。因此,提出的算法在一定程度上降低了延时。算法通过事先设定最低RSSI和节点最大剩余能量MRE来构建路由树,并修改已存在的路由算法,从而保证节点通讯的可靠性和网络的节能。  相似文献   

9.
王璐  李爱玲 《电子器件》2012,35(4):457-460
针对无线Ad hoc网络多跳,拓扑结构随时可能动态变化,协作节点间数据传输需实时性强等问题,利用Netlog语言宣告声明最小Steiner树协议的构造算法方法适应解决。协议可快速构造一棵近似最小的Steiner树,每个节点独立运行声明Steiner树协议,构造Steiner节点间的虚拟全联通网络,在此网络上构造最小代价生成树;然后将此树的节点与边对应原网络的节点和边,继续构造最小代价生成树,最后将此树上的非Steiner节点的叶子节点删除,近似得到最小代价Steiner树,该方法在实验平台上得以验证,为无线移动网络中资源的选择利用提供了一种新的可尝试性的新方法。  相似文献   

10.
在指挥决策实体任务协作关系构成的协作交流网基础上,提出了一种设计指挥决策实体层次结构(指挥控制树)的新方法。该方法定义根节点到其他节点路径长度的最大值为树高,以构造树高最小的生成树为目标,对于取定的根节点,计算根节点到其他每个节点的唯一最短路径,对这些最短路径进行并操作得到的即为指挥控制树。最后结合一个案例,验证了应用该方法生成指挥控制树的可行性。  相似文献   

11.
Most-vital edge of a graph with respect to spanning trees   总被引:1,自引:0,他引:1  
A most-vital edge of a connected graph with respect to spanning trees is an edge whose removal most reduces the number of spanning trees. Tsen et al. (1984) proposed a solution to the problem, based on determining the adjoint of a matrix of order n (n=number of nodes of the graph). This paper presents a solution based on determining the adjoint of Ψ≡A×At (A=reduced incidence-matrix of the graph); the order of Ψ is (n-1). This procedure leads to a resistance-analog method to determine the vital edge of a graph with respect to the spanning trees  相似文献   

12.
A global reliability measure called 'network reliability' (NR) is the probability that a call entering a probabilistic network at any originating node can reach every other node. This concept is quite useful in multiterminal networks such as computer networks and parallel processors, etc. A simple technique is presented for evaluating NR in symbolic form. The method is based on cutsets and is computationally advantageous with respect to the spanning tree approach. It requires fewer cutsets to be manipulated in the process of determining the NR expression. The number of cutsets is approximately half that of spanning trees even for a small sized computer communication network and there is a further improvement in the situation for larger networks.  相似文献   

13.
A distributed algorithm is presented for constructing minimum weight directed spanning trees (arborescences), each with a distinct root node, in a strongly connected directed graph. A processor exists at each node. Given the weights and origins of the edges incoming to their nodes, the processors follow the algorithm and exchange messages with their neighbors until all arborescences are constructed. The amount of information exchanged and the time to completion areO(|N|^{2}).  相似文献   

14.
A most vital edge of a graph (w.r.t. the spanning trees) is an edge whose deletion most drastically decreases the number of spanning trees. We present an algorithm for determining the most vital edges based on Kirchoff's matrix-tree theorem whose asymptotic time-complexity can be reduced to that of the fastest matrix multiplication routine, currently O(n2.376). The foundation for this approach is a more general algorithm for directed graphs for counting the rooted spanning arborescences containing each of the arcs of a digraph. A network can be modeled as a probabilistic graph. Under one such model proposed by Kel'mans, the all-terminal network reliability, maximizing the number of spanning trees is critical to maximizing reliability when edges are very unreliable. For this model, the most vital edges characterize the locations where an improvement of the reliability of the link most improves the reliability of the network  相似文献   

15.
胡钢  高浩  徐翔  许丽鹏 《电子学报》2000,48(12):2402-2408
复杂网络中节点重要性辨识对分析网络结构和功能具有重要作用.为了辨识节点重要性,分析节点自身和关联节点的作用,本文构建了一种基于重要度传输矩阵的节点重要性辨识模型.首先,基于关联节点与节点之间的最优路径长度、最优路径数目和信息传播率定义了节点间的传输能力.其次,依据度值和传输能力构建重要度传输矩阵,综合节点局部重要性和全局属性指标评价节点的重要性.最后,对"ARPA"网络和四个真实网络进行破坏性仿真分析,结果本文方法表明对网络造成更大的破坏,证明了该方法的有效性和可靠性.  相似文献   

16.
Localized broadcast incremental power protocol for wireless ad hoc networks   总被引:2,自引:0,他引:2  
We investigate broadcasting and energy preservation in ad hoc networks. One of the best known algorithm, the Broadcast Incremental Power (BIP) protocol, constructs an efficient spanning tree rooted at a given node. It offers very good results in terms of energy savings, but its computation is centralized and it is a real problem in ad hoc networks. Distributed versions have been proposed, but they require a huge transmission overhead for information exchange. Other localized protocols have been proposed, but none of them has ever reached the performances of BIP. In this paper, we propose and analyze an incremental localized version of this protocol. In our method, the packet is sent from node to node based on local BIP trees computed by each node in the broadcasting chain. Local trees are constructed within the k-hop neighborhood of nodes, based on information provided by previous nodes, so that a global broadcasting structure is incrementally built as the message is being propagated through the network. Only the source node computes an initially empty tree to initiate the process. Discussion and results are provided where we argue that k = 2 is the best compromise for efficiency. We also discuss potential conflicts that can arise from the incremental process. We finally provide experimental results showing that this new protocol obtains very good results for low densities, and is almost as efficient as BIP for higher densities.  相似文献   

17.
基于生成树的无线传感器网络分布式路由协议   总被引:4,自引:4,他引:0  
在无线传感器网络中,节点具有有限的电池能量,为了延长网络的生存时间,提出了一种基于生成树的分布式路由协议STRP及其具有能量意识的改进版本STRP-PA.每个传感器节点根据相邻节点与基站的距离、剩余能量等信息寻找父节点,构造一棵以基站为根的近优最小生成树,节点采集的数据沿树传输,并在树杈节点进行聚合.仿真实验结果表明:STRP-PA协议能够节省网络能量,显著延长网络稳定工作的时间,性能明显好于LEACH协议.  相似文献   

18.
Graph G has perfectly reliable nodes and edges that are subject to stochastic failure. The network reliability R is the probability that the surviving edges induce a spanning connected subgraph of G. Analysis problems concern determining efficient algorithms to calculate R, which is known to be NP-hard for general graphs. Synthesis problems concern determining graphs that are, according to some definition, the most reliable in the class of all graphs having a given number of edges and nodes. In applications where the edges are perfectly reliable and the nodes are subject to failure, another measure (residual node connectedness reliability) is defined as the probability that the surviving nodes induce a connected subgraph of G. Referring to such a subset as an operating state, the measure is not coherent because a superset of an operating state need not be an operating state. This paper proposes a new definition of network reliability that handles the case of node failures; it is coherent. We determine many of its properties, and present several analysis and synthesis results  相似文献   

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