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网络抗毁能力是确保信息畅通的重要支撑。给出了网络抗毁性的定义,对网络化信息系统进行图论表示。基于系统的核与核度定义,给出了图的核与核度定义。在此基础上,以某网络化信息系统拓扑结构为例,计算出该网络的核与核度,分析了该网络化信息系统在核度意义下的抗毁性能。计算结果表明,该网络化信息系统不具有核度意义下抗毁性最好的拓扑结构。节点13是这个网络化信息系统的"核",应予以重点保护。 相似文献
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度量社交网络节点影响力是社交网络结构分析的关键问题之一。目前研究社交网络节点影响力的方法主要有两大类:中心度方法和节点删除方法。前者主要通过度或最短路径等因素来判断节点的影响力,不考虑网络的连通性;后者通过节点删除后对网络结构的破坏程度来判断,计算复杂性很高,不适用于较大规模的社交网络。通过结合社交网络的局部连通度及节点间的最短路径,提出了连通中心度来度量社交网络中节点的影响力,并给出了连通中心度的计算方法和一些特殊网络中节点的连通中心度的值。最后,通过实验说明该指标能很好地度量社交网络中节点的影响力。 相似文献
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本文把讯号流图推广到有向矩阵系统,提出一种广义的讯号流图定义及其拓扑法则,并给出了复杂网络系统的若干应用实例。 相似文献
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为了提高图像分割的质量,采用支持向量机核函数算法。首先寻找像素分类间隔最大的最优分类面,将非线性输入空间的样本映射到高维特征空间进行求解;然后局部核函数选择高斯径向基核函数,全局核函数选择多项式核函数,为了满足训练集中支持向量取值带来的连续性要求,通过组合系数平衡高斯核函数和多项式核函数的权重;接着选择像素的邻域灰度均值作为用于分割的特征,利用不规则度统计图像邻域灰度均值连通区域的离散程度;最后给出了算法流程。实验仿真显示本文算法分割图像清晰,目标区域十分突出,定性分析中指标归一化互相关系数为0.9946,分割时间为0.7512,误割率为0.0237。 相似文献
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弱非线性动态系统Volterra核自动测试系统的研究 总被引:1,自引:0,他引:1
本文讨论弱非线性动态系统Volterra核自动测试系统的研制,应用Volterra泛函级数和计算机技术于非线性系统,本文结合频率域多点测量弱非线性系统前二阶核的算法QMMP2及测量前三阶核的算法QMMP3,设计了自动测试系统。本文给出应用该系统的两个测量实例。 相似文献
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基于后缀树词序列核挖掘Web文档 总被引:1,自引:1,他引:0
通过将文档表示为一棵后缀树,文章提出一种基于后缀树索引计算文档相似度的词序列核.首先根据文档的词序列构造出后缀树,然后根据后缀树词序列核计算文档间的相似度,最后利用支持向量机对文档进行分类.理论分析表明后缀树词序列核的计算只与比较文档的长度成线性关系,大大减少了序列核的计算时间.在reuters21578文档集上将后缀树词序列核与词序列核、多项式核进行比较,实验结果表明在改善速度的同时,后缀树词序列核可达到与词序列核相当的性能,优于多项式核,更适于Web文档挖掘等应用. 相似文献
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针对动态卫星光网络中的波长资源紧缺问题,研究了其波长数与网络物理连通度的关系,提出了一种基于时空冲突图的波长资源特性分析方法。利用随机生成网络拓扑连接的方式,将卫星光网络的动态拓扑离散为空间和时间冲突图,分别表示网络的物理连通度和有效窗口。基于时空冲突图理论,建立空间冲突避免的路径选择概率和时间存储的有效窗口业务概率,两者相乘得到时空冲突概率,进而计算网络所需波长数。研究结果表明,波长需求与网络物理连通度、链路最大跳数和转发器数目有着密切关系,在业务重叠因子较大的情况下应该给卫星光网络分配更多的波长资源。 相似文献
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该文针对卫星组网的特点,研究基于SNMP(Simple Network Management Protocol)的被动测量方法在卫星网络流量测量中的应用。首先介绍采用SNMP测量网络流量的基本原理。在此基础上引入监控节点选择算法,以减少监测设备的数量,提高网络流量测量性能。最后给出了实际开发的应用程序及实验结果。利用该结果可进一步计算或统计处理,进而确定卫星网中资源的分配和使用,调整网络达到最佳性能。该文实现的完整流量测量,为卫星网络实施流量工程提供了实时准确的数据和有效的网络管理依据。 相似文献
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The continuously increasing complexity of communication networks and the increasing diversity and unpredictability of traffic demand has led to a consensus view that the automation of the management process is inevitable. Currently, network and service management techniques are mostly manual, requiring human intervention, and leading to slow response times, high costs, and customer dissatisfaction. In this paper we present AutoNet, a self-organizing management system for core networks where robustness to environmental changes, namely traffic shifts, topology changes, and community of interest is viewed as critical. A framework to design robust control strategies for autonomic networks is proposed. The requirements of the network are translated to graph-theoretic metrics and the management system attempts to automatically evolve to a stable and robust control point by optimizing these metrics. The management approach is inspired by ideas from evolutionary science where a metric, network criticality, measures the survival value or robustness of a particular network configuration. In our system, network criticality is a measure of the robustness of the network to environmental changes. The control system is designed to direct the evolution of the system state in the direction of increasing robustness. As an application of our framework, we propose a traffic engineering method in which different paths are ranked based on their robustness measure, and the best path is selected to route the flow. The choice of the path is in the direction of preserving the robustness of the network to the unforeseen changes in topology and traffic demands. Furthermore, we develop a method for capacity assignment to optimize the robustness of the network. 相似文献
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下一代网的发展原动力,主要来自市场对宽带服务的需求。接入网的提速、城域网到核心网100 G系统的引入、LTE推动移动核心网向IMS、EPC演进,都在推动NGN向纵深发展;富媒体套件、深层包检测业务量管控、策略管理技术也将推进网络智能的进一步提升。 相似文献
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The advanced techniques presently used by AT&T to manage traffic flow in its Worldwide Intelligent Network are described. The role of traffic network management strategies is reviewed, and the scope and routing plan of the AT&T Worldwide Intelligent Network are characterized. Three examples of modern protective controls are considered: selective trunk reservation, hard-to-reach process, and selective dynamic overload control. Advanced network management expansive controls and AT&T's traffic network management support systems are examined. Dynamic graphical analysis of network data, interactive training of network managers, and future trends impacting traffic network management are discussed 相似文献
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Advanced traffic control methods for network management 总被引:1,自引:0,他引:1
The objectives of network management control are outlined, and two categories of control are defined: network traffic controls and network configuration controls. Network traffic controls are further classified into traffic volume controls and routing controls, and advanced techniques for achieving each of them are examined. Two classes of methods for specifying the amount of traffic to be controlled are described. In proportional control, a certain proportion of the traffic offered by each exchange is admitted; in threshold control, there is a maximum rate at which the traffic offered by each exchange is admitted. The TCS-V2 traffic-control system, an advanced automatic code-blocking system that uses area and subscriber congestion control, is considered, and the simulated performance of proportional control and threshold control is compared for this system. For routing control, an advanced state-dependent dynamic routing scheme is examined, and the results of a comparative evaluation of dynamic routing schemes are presented 相似文献
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当前LTE网络话务区域分布不均及潮汐效应凸显,传统的容量管控手段已无法高效应对。载波智能调度系统可以实现动态的载波调度,有效应对这种现状。本文首先介绍平台的系统功能设计,然后阐述该系统的架构和组成模块以及算法策略,最后介绍了该系统的应用效果。 相似文献
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文章在对IP网络几种主要的流量测量和分析技术进行比较的基础上,以上海电信IP城域网为对象,通过流交换(netflowswitchin)g方法收集流量信息,进而利用工具分析了流量流向、流量应用分布等现网流量的特点。对流交换数据量与网络流量之间的定量关系也做了实测估计。 相似文献