基于进化规划的多层前向网络结构优化

基于进化规划(EP)方法,该文提出了设计多层前向网络拓扑结构和权值分布的一种新算法EPANN算法。EPANN算法能同时进化网络的结构和连接权值(包括阈值),在进化过程中,强调父代和子代之间的行为联结,结构变异既有结点删除,又有结点增加,不同于单纯的删除算法或构造算法,且结点删除总是先于结点增加,保证了网络规模尽可能小而泛化能力尽可能强。     

网络社区发现优化：基于随机游走的边权预处理方法

在网络日趋复杂化、巨大化的背景下,仅依靠网络拓扑特征难以提高现有社区发现算法的精确度和性能。该文提出一种优化网络社区发现的边权预处理方法,基于马尔可夫随机游走理论建模社区结构对复杂网络行为的影响,根据多重随机游走对网络连接的遍历情况,重新衡量网络边权。预处理后的边权作为网络拓扑的有效补充信息,能够将网络社区结构去模糊化,从而改善现有算法的社区发现性能。对于一些典型的计算机生成网络和真实网络,经实验验证：该预处理方法能够有效提升现有部分社区发现算法的准确性和效率。     

片上网络节点编码的设计和在路由方面的应用

网络拓扑选择和路由算法设计是片上网络设计的关键问题.在比较现有的三种网络拓扑结构的基础上,提出了一种隐含着相邻节点以及节点之间链路关系并适合二维Torus拓扑结构的节点编码方法.该编码和Torus结构的结合能拓扑结果够简化路由算法的设计和实现,改善了网络路由性能.实验结果表明,提出的编码方法与二维Torus拓扑结构的结合有效地提高了片上网络通信性能.     

“遗传算法”在计算机网络可靠度优化计算中的作用

以保证计算机网络传输系统的可靠作为前提,怎样有效地降低网络结点链路成本,逐渐成为了当前计算机网络可靠度优化的主要方向。而遗传算法相对于传统的算法来说,有着搜索高效、求解便捷和算法结构简便等优点,做全局的计算时能够得到最优的相似值。文章在确保计算机网络链路介质成本与网络可靠度数学模型因素之时,对遗传算法在计算机网络可靠度优化计算中的作用进行了分析。     

基于代数连通度优化的空间信息网络分布式拓扑控制方法

针对空间信息网络中节点高速运动导致的网络拓扑结构难以长期稳定的问题,本文提出了基于代数连通度优化的网络动态拓扑控制方法,通过少量链路调整来维持网络拓扑的稳定性.为减小空间信息网络节点持续相对运动对网络拓扑结构稳定性造成的不利影响,针对网络初始化和网络重构场景,采用图论中的拉普拉斯矩阵特征值优化思想,构建了星上资源约束条件下的加权代数连通度最大化模型.为降低计算复杂度来实现网络拓扑的捷变控制,提出了基于连通矩阵弱摄动的动态网络拓扑控制策略.研究结果表明,提出的算法能够通过内点法,可高效地得到次优解,且次优解与全局最优解十分接近.     

基于FW-PSO算法优化无线传感网络拓扑结构的方法

无线传感网络(WSN)具有无标度网络的特征,通常工作在无人值守的开放性环境中,极易遭受到各种蓄意攻击.攻击使得网络发生故障,甚至会导致整个网络瘫痪.该文基于复杂网络领域的无标度网络,构建具有无标度特性的无线传感网络模型.利用烟花算法及粒子群算法(PSO)寻优过程中的搜索能力、种群多样性等优点,提出了一种FW-PSO算法,该算法在全局搜索能力和收敛速度上具有较好的性能.针对具有无标度特性的网络模型,用FW-PSO算法对网络拓扑进行优化,在不同的攻击策略下分别从动态抗毁性和静态抗毁性分析优化前后网络的性能.仿真实验表明,与其他同类算法相比,经过该文所提算法优化后的无线传感网络的动态和静态抗毁性能都有明显提升.     

多粒度光网络故障定位

多粒度光网络中多种粒度光通道的存在,任何故障均会造成网络服务质量的降低。一方面多粒度光网络具有单粒度光网络故障传播的特性;另一方面多粒度光网络的故障又分为不同的层,每一层对应一种类型的故障。通过对多粒度光网络光通道、光节点的分析,抽象出可告警不同粒度故障的物理信道模型,并将二叉树算法应用在模型中,实现故障位置和故障粒度的定位,并且对网络拓扑结构没有特殊的要求。     

基于改进蚁群算法的WDM光网络恢复优化

针对WDM光网络的恢复,提出一种基于蚁群算法(ACA)的WDM光网络恢复优化算法,算法以WDM光网络的虚拓扑为主要研究对象,模拟蚂蚁寻址方式获得网络业务受损节点恢复方案.在优化过程中,结合免疫算法的变异操作对全局业务分配进行自适应调节,以获得更高的故障恢复率水平,最终实现网络受损业务恢复,使整个网络资源利用率达到最优.仿真结果表明,该算法可满足较高的恢复率需求情况,并可应用于任意形式WDM网络拓扑结构.     

Tracker中一种具有拓扑意识的结点选择算法(TAPS)

BitTorrent系统是当前最流行的P2P文件共享系统,但因其Tracker采用随机的结点选择算法从而造成了大量的冗余网络流量。文章提出一种基于拓扑意识的结点选择算法TAPS,根据网络拓扑信息进行结点选择。经过仿真实验证明,TAPS(10,40,∞)在保证BitTorrent应用性能的前提下极大地减少了骨干网流量和网络负载。     

多目标的Internet路由优化控制算法

研究通过优化链路权值以控制网络路由来实施流量工程.以网络拥塞最小化和时延最小化为流量工程目标,建立了多目标的全局路由优化数学模型.求解该问题是NP困难的,提出一种混沌群搜索优化算法进行求解.算法采用群局部搜索,利用混沌变量产生一组分布好的初始解,并在邻域搜索进程中应用扩展贪心思想,提高了算法的全局搜索能力.仿真结果表明所提算法能够有效减少由于流量分布不平衡造成的网络拥塞,同时限制长路径,提高了网络性能.     

Automatic Update of Replicated Topology Databases

In computer communication networks, routing is often accomplished by maintaining copies of the network topology and dynamic performance characteristics in various network nodes. The present paper describes an algorithm that allows complete flexibility in the placement of the topology information. In particular, we assume that an arbitrary subset of network nodes are capable of maintaining the topology. In this environment, protocols are defined to allow automatic updates to flow between these more capable nodes. In addition, protocols are defined to allow less capable nodes to report their topology data to the major nodes, and acquire route information from them.     

Topology control for fault-tolerant communication in wireless ad hoc networks

Fault-tolerant communication and energy efficiency are important requirements for future-generation wireless ad hoc networks, which are increasingly being considered also for critical application domains like embedded systems in automotive and aerospace. Topology control, which enables multi-hop communication between any two network nodes via a suitably constructed overlay network, is the primary target for increasing connectivity and saving energy here. In this paper, we present a fault-tolerant distributed topology control algorithm that constructs and continuously maintains a k-regular and k-node-connected overlay for energy-efficient multi-hop communication. As a by-product, it also builds a hierarchy of clusters that reflects the node density in the network, with guaranteed and localized fault-tolerant communication between any pair of cluster members. The construction algorithm automatically adapts to a dynamically changing environment, is guaranteed to converge, and exhibits good performance as well.     

一种基于邻域信息的多信道自适应建网算法

为实现多信道无线自组网的高效建网,针对节点难以感知全网拓扑、其他所有节点的可用频谱以及无法获得同步信息的实际场景,提出了一种基于邻域信息的多信道自适应建网算法。该算法首先设计基于邻域信息的建网策略,使节点能够以自身信息为基础,充分利用可用信道情况、邻居簇首情况等有限的邻域信息进行自适应决策,以建立分簇结构的网络;然后提出基于最大熵原理的信道质量评价算法和基于多头绒泡菌模型的邻居簇首评价算法,分别对节点的可用信道和邻居簇首进行排序,指导节点在建网过程中选择合理的信道和簇首。仿真结果表明,所提建网算法能够使节点在实际场景通信受限的条件下以较小的通信开销完成建网,建立的网络在公共信道数量和簇规模方面也取得了较好的均衡。      

Cluster‐based data dissemination,cluster head formation under sparse,and dense traffic conditions for vehicular ad hoc networks

Information and communication technologies have changed the way of operations in all fields. These technologies also have adopted for wireless communication and provide low cost and convenient solutions. Vehicular ad hoc networks are envisioned with their special and unique intercommunication systems to provide safety in intelligent transportation systems and support large‐size networks. Due to dense and sparse traffic conditions, routing is always a challenging task to establish reliable and effective communication among vehicle nodes in the highly transportable environment. Several types of routing protocols have been proposed to handle high mobility and dynamic topologies including topology‐based routing, position and geocast routing, and cluster‐based routing protocols. Cluster‐based routing is one of the feasible solutions for vehicular networks due to its manageable and more viable nature. In cluster‐based protocols, the network is divided into many clusters and each cluster selects a cluster head for data dissemination. In this study, we investigate the current routing challenges and trend of cluster‐based routing protocols. In addition, we also proposed a Cluster‐based Routing for Sparse and Dense Networks to handle dynamic topologies, the high‐mobility of vehicle nodes. Simulation results show a significant performance improvement of the proposed protocol.     

认知网络中基于簇结构的拓扑形成算法

在多跳的认知无线网络中,网络的拓扑发现算法都必须极其灵活以适应于环境内频谱空洞的改变。研究了认知无线电网络的基本特点,结合Ad-hoc网络簇的概念,在得到认知设备的感知结果的基础上,提出了一种适合于认知无线电网络的有效的拓扑形成算法。在提出的算法中,将可用的频谱空洞信息和节点的能量信息综合考虑,是一个组合的优化算法。     

Energy and delay efficient dynamic cluster formation using hybrid AGA with FACO in EAACK MANETs

MANET is a set of mobile nodes which works in a dynamic changing network and it is capable of communicating with each other efficiently where all the nodes perform a dual role as that of a transmitter and a receiver. MANETs do not use any centralized administration for communication. The performance of a MANET can be further enhanced by adapting a cluster mechanism with the help of CEAACK to provide security from penetrators. In this paper we propose a new improved ant colony optimization algorithm with two strategies to reduce the overhead in communication by predicting mobility of node and cluster formation. Firstly, a dynamic mechanism is designed for determining one or more heuristic parameters for improving the performance of the MANET. Secondly a dynamic list of nodes are maintained which helps in forming clusters and electing the cluster head faster. In addition a dynamic broadcast approach algorithm is incorporated to provide the information about the status of the nodes to the hybrid fuzzy-ant colony algorithm. This approach ensures low maintenance cost and is expected to be robust against node failures and network topology changes. The positive outcome of these two techniques consumes low energy and in the process provides better efficiency in data transmission in MANETs. It also achieves correct delivery of packets without unnecessary delay.     

网络分层的水下传感器网络覆盖保持路由算法

在以监测为目的的水下传感器网络中,较好的网络覆盖率和连通率是完成监测任务的重要保证.以改善覆盖效果为目标的水下覆盖保持路由算法NCPR算法相对比LEACH-Coverage-U算法有效的延长了网络覆盖时间,但是该算法连通性表现较差,同时存在靠近SINK节点的簇首由于需要转发大量数据而过早死亡的问题.本文提出一种分布式的网络不均匀分层的覆盖保持路由(Network Unevenly Layered Coverage Preserving Routing,NULCPR)算法,由SINK节点开始逐层向下建立网络,同时每层网络节点通信半径也随层号增加而逐渐增大.每层网络独立运行NCPR算法以使该层节点成簇,并通过簇首向上建立连通链路以保证网络连通.仿真结果表明,与NCPR算法相比,NULCPR算法提高了网络连通率以及覆盖率,并且降低了网络能耗,证明了该算法的有效性.     

基于无线传感器网络的K均值算法研究

传统无线传感网一般由大量密集的传感器节点构成,存在节点计算能力、能源和带宽都非常有限的缺点,为了有效节能、延长网络寿命,介绍了基于聚类的K均值算法.该算法通过生成的簇头节点散播到网络的各个区域中,减少了每个区域内通信的能耗和可能会出现的一般节点过早死亡的情况,从而避免了网络对该区城提早失去监控.实验证明,该算法对各节点...     

Reliability Evaluation of a Network with Delay

In a computer or communication network, the reliability and transfer-delay of communication are important measures of performance. This paper describes a method of evaluating the reliability of a network with delay. When network elements fail, delay is defined as the length of the shortest remaining path between two specified nodes. We find the occurrence probability of events that a central node can communicate with a group of terminal nodes so that a specified delay is not exceeded. The desired events are mutually exclusive and contain a tree. Our algorithm efficiently generates all the events by noting network topology. The paper includes the case of several central nodes.     

Energy-Efficient Routing Algorithm Based on Unequal Clustering and Connected Graph in Wireless Sensor Networks

Clustering and multi-hop routing algorithms substantially prolong the lifetime of wireless sensor networks (WSNs). However, they also result in the energy hole and network partition problems. In order to balance the load between multiple cluster heads, save the energy consumption of the inter-cluster routing, in this paper, we propose an energy-efficient routing algorithm based on Unequal Clustering Theory and Connected Graph Theory for WSN. The new algorithm optimizes and innovates in two aspects: cluster head election and clusters routing. In cluster head election, we take into consideration the vote-based measure and the transmission power of sensor nodes when to sectionalize these nodes into different unequal clusters. Then we introduce the connected graph theory for inter-cluster data communication in clusters routing. Eventually, a connected graph is constituted by the based station and all cluster heads. Simulation results show that, this new algorithm balances the energy consumption among sensor nodes, relieves the influence of energy-hole problem, improve the link quality, achieves a substantial improvement on reliability and efficiency of data transmission, and significantly prolongs the network lifetime.