通信网中节点重要性的评价方法

提出了一种对通信网中节点重要性进行评价的方法,并给出了简洁的归一化解析表达式。通过比较生成树的数目,可以判断图中任意数目的两组节点的相对重要性。从图中去掉节点以及相关联的链路后,所得到的图对应的生成树数目越少,则表明该组节点越重要。实验结果表明,该方法计算简单,更为精确地反映基于网络拓扑的节点重要性。     

基于互信息的通信网络节点重要性度量方法

信息化条件下的复杂网络对节点的蓄意攻击非常脆弱,因此准确发掘出网络中的核心节点并进行重点保护对提高网络抗毁性至关重要.在分析特殊条件下通信网络特征属性的基础上,借鉴通信系统中关于“信息量”的定义方法,提出了改进的适用于有向加权网络的节点重要性评估方法.在小规模混合加权网络中对该方法和已有方法进行了对比分析,验证了本文方法的有效性和优势性.构建了一种基于BBV(Barrat-Barthelemy-Vespignani)的混合加权网络演化模型,并对生成的大规模通信网络进行了节点重要性评估仿真,实验结果表明:与现有评估方法相比,本文方法能够更加简单、有效地评估网络节点的重要性.     

一种野战地域通信网网络节点和链路重要性的评估方法

评估网络节点和链路的重要性,是研究野战地域通信网网络可靠性的重要内容。在采用节点收缩法判断网络节点重要性的基础上,结合实例,提出了利用层次分析法确定连接于核心节点的各条链路权重值的方法,进而得出野战地域通信网网络节点和链路重要性的评估方法,为野战地域通信网的可靠性研究和电子对抗作战提供参考。     

基于重要度传输矩阵的复杂网络节点重要性辨识方法

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.     

基于CC2431的无线传感器网络节点的设计

CC2431是Chipcon公司新推出的符合Zigbee标准并具有定位功能的无线射频芯片,设计该节点可以为无线传感器网络提供较高质量的硬件定位功能.在简要介绍无线传感器网络及其节点的特征后,详细介绍了CC2431的性能及特征,并结合CC2431的外部接口及电气特性,利用模块化的设计方法定制节点中的各个功能模块,最终实现了集处理器8051与通信模块于一体的基于CC2431的无线传感器网络节点.     

信号强度和运动向量结合的无线传感器网络移动节点定位

无线传感器网络的定位是近年来无线传感器网络研究的重要课题.本文首先介绍了无线传感器网络的来源、重要性以及无线传感器网络定位的分类.然后提出了一种全新定位算法,信号强度和运动向量结合的无线传感器网络移动节点定位,简称SSMV算法,在外围布置四个锚节点,得用信号强度和未知节点在运动中向量的变化,对锚节点在内的未知节点进行定位,并对该算法进行了仿真和总结.通过与凸规划法进行比较,仿真结果表明,该算法有更高的定位精度.     

面向异构无线传感器网络的节点调度算法

针对传感器网络中的节点冗余问题,提出了一种冗余判别方法来关闭冗余节点,以达到延长网络生命周期的目的.首先按邻居节点的不同位置对节点进行分类,研究了每组邻居节点的网络覆盖率与工作节点数k之间的约束关系,在此基础上,按不同的冗余法则对节点进行判断,关闭冗余节点.理论分析和实验结果表明,提出的算法能关闭网络中的冗余节点从而有效地延长网络的生存时间.     

基于聚合度的地域通信网关键节点识别方法

分析了地域通信网的网络模型,从网络的拓扑结构出发,以图论知识为基础,把节点的度数和聚合度作为衡量节点重要性的标准,给出了关键节点的定义方法,通过分析对比得出地域通信网中有些关键节点并不具有较大的度分布特征,而且链路之间存在着一定的差别,采用度作为节点重要性的评估方法具有一定的片面性。在此基础上,文中提出了一种基于聚合度大小排序的关键节点识别方法,并给出了关键节点识别流程。实例分析结果表明了该方法的有效性、简单性和准确性。     

WSNs中基于数据匹配的分布式故障节点检测算法

针对无线传感网络的节点故障问题,提出一种新的分布式故障节点检测算法(DFDA).DFDA算法利用节点度信息估计节点对网络的重要性,并尽可能将节点度高的节点保存到网络中.通过比较节点间感测的数据,检测故障节点.为了增强检测的准确性,采用双重测定策略.仿真结果表明,相比于同类算法,DFDA算法提高了检测故障节点的精确度,并...     

基于最短路径数的网络抗毁评价方法

由于全连通网络具有最强的抗毁性,且节点间最短路径数对于网络抗毁性有重要意义,通过对计算节点之间的最短路径数,并将待评价网络与全连通网络进行结构差异比较,提出了一种基于最短路径数的网络抗毁评价方法.在此基础上建立了网络节点重要性的评价模型,一个节点与网络中其他节点之间的平均等效最短路径数越多,则该节点越重要.由于评价模型的关键是最短路径数的计算,因此,还提出了一种基于邻接阵的最短路径数计算方法.     

通信网中链路重要性的评价方法

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.     

Most-vital edge of a graph with respect to spanning trees

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×A^t (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     

A Distributed Algorithm for Minimum Weight Directed Spanning Trees

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}).     

A Cutset Approach to Reliability Evaluation in Communication Networks

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.     

光网络中基于组播树的静态业务疏导算法

为了减少波分复用(WDM)网络中波长资源消耗,将组播路由算法的思想运用于静态业务疏导的计算,通过建立业务疏导树来实现静态业务疏导.为了减少疏导树的数量,从而减少网络中波长资源的消耗,将节点间的业务请求分组归并,利用装包算法使业务分组的数量最少,并通过构建最小生成树实现传输路径共享.仿真结果表明,本文的算法可以有效地减少...     

Localized broadcast incremental power protocol for wireless ad hoc networks

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.     

指挥决策实体层次结构设计方法

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。     

Finding the most vital edges with respect to the number of spanningtrees

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(n^2.376). 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     

Design Method Based on Routing Tree for Topology Update in Ad Hoc Network

Ad hoc network is a kind of infrastructureless and self-organized mobile network. The wireless communication range of mobile nodes is limited in ad hoc network. The nodes can’t communicate with each other directly, but resort to the other adjacent nodes to forward their packets and exchange information of nodes. Every node not only serves as the mobile terminal, but also is able to store and forward packets[1]. Therefore, the node can be regarded as a router in ad hoc network. It finds the p…