网络安全性

Based on switching network,the technology of Virtual Local Area Network is applied to construct a logical network which spans different subnet.It can avoid the network broadcast storm in order to improve the performance,security and expansion of whole campus network.

VLAN是在交换网络的基础上构建可跨越不同网段、不同网络的端到端的逻辑网络，可避免校园网广播风暴的出现，以提高整个校园网的安全性和可扩展性。

VLAN divided after the broadcast domain as a result of the reduced network by broadcasting packets to reduce bandwidth consumption, contribute to the emergence of broadcast storm control, reduce equipment investment, simplifying network management, improve network performance and security.

划分VLAN 后，由于广播域的缩小，网络中广播包所消耗的带宽减少，有助于控制广播风暴的产生、减少设备投资、简化网络管理、提高网络的性能和安全性。

Seek science and humane circulation, nomatter on the natural space, or in the field of the society, or is launchingomni-directionally during the process of studying , for example drink the ethicsproblem of the Human Genome Project to the security of the transgenic food, geneticengineering expert and ethicist have produced common attention , and the arrival ofcybertimes and prosperity of network culture, make the expert and art of the networktechnology learn to form alliances in the family again.

寻求科学与人文的融通，无论在自然的空间上，还是在社会的领域中，或是在研究的过程中，都全方位地展开着，比如对于转基因食物的安全性喝人类基因组计划的伦理问题，基因工程专家同伦理学家产生了共同的关注点，而网络时代的到来以及网络文化的繁荣，又使得网络技术的专家和艺术学家结成了联盟。

In terms of network operation, A-IMS as extensions to IMS/MMD enhances the IMS/MMD network security with the addition of Security Operation Center, posture agent, etc.

另外还从网络运营的角度，针对IMS/MMD网络安全提出了一些扩展和补充，如增加了安全操作中心和姿态代理等，使IMS/MMD网络的安全性得到较大改进。

In terms of network operation, A-IMS as extensions to IMS/MMD enhances the IMS/MMD network security with the addition of Security Operation Center, posture agent,.

另外还从网络运营的角度，针对IMS/MMD网络安全提出了一些扩展和补充，如增加了安全操作中心和姿态代理等，使IMS/MMD网络的安全性得到较大改进。

TheAdvancestoIP Multimedia Subsystem architecture, built on the 3rd Generation Partnership Project 2 (3GPP2)'s Multimedia Domain, supports both IMS/MMD and non-Session Initiation Protocol services. In terms of network operation, A-IMS as extensions to IMS/MMD enhances the IMS/MMD network security with the addition of Security Operation Center, posture agent, etc. Some parts of the A-IMS framework are still under development sUCh as terminal support for the posture agent, security information exchange, and security policy definition.

改进的IP多媒体子系统基于3GPP2的多媒体域架构，包含了所有IP多媒体子系统/多媒体域业务功能，并增加了对非会话发起协议应用的支持；从网络运营的角度，针对IMS/MMD网络安全提出了一些扩展和补充，如增加了安全操作中心和姿态代理等，使IMS/MMD网络的安全性得到了较大改进。A-IMS仍处于框架性描述阶段，还有很多细节尚不明确，如终端对姿态代理的支持能力、安全信息交换的内容、安全策略的具体定义等，有待于进一步研究。

The former firstly establishes state graph of power system, and then, with the use of the adjacency matrix and path matrix of the directed graph, fast finds out the key transmission sections suffering greatly from the outages of overload lines through simple calculation of matrix.

前者根据实时网络拓扑结构和潮流分布状态，在对初始电力网络简化、分区的基础上，利用有向图的邻接矩阵与路径矩阵，通过简单的矩阵运算，快速识别出与过载线路相关的关键输电断面；后者直接利用系统各支路的阻抗，从图论算法的基本思想出发，搜索最易遭受大负荷转移的关键传输路径，从而将安全性分析目标从整个网络缩小到某些关键的输电线路。

The former firstly establishes state graph of power system, and then, with the use of the adjacency matrix and path matrix of the directed graph, fast finds out the key transmission sections suffered greatly from the outages of overload lines through simple calculation of matrix. In the latter, the minimal short transmission path, the length of which is calculated with line impedance, is determined with graph theory to focus on security analysis objects from the whole network to some key transmission lines.

前者根据实时网络拓扑结构和潮流分布状态，在对初始电力网络简化、分区的基础上，利用有向图的邻接矩阵与路径矩阵，通过简单的矩阵运算，快速识别出与过载线路相关的关键输电断面；后者直接利用系统各支路的阻抗，从图论算法的基本思想出发，搜索最易遭受大负荷转移的关键传输路径，从而将安全性分析目标从整个网络缩小到某些关键的输电线路。

Then, we make the expansive research on the protocol, using this mechanism of key predistribution and storage in the network of the same construction. And finally, we simulate the protocol on the platform OMNeT++.

基于层次结构的路由协议能保证网络有效的最短距离路由，簇内和簇间不同类型的共享组密钥的应用保证网络良好的安全性，使网络性能更加完善。

Secondly, most of typical scheme for MANET multicast reking are based inbalanceable key tree, the most import problem of multicast reking is providingforward security when member leaves and backward security when member join, then,how to improve efficient of multicast reking, decrease the cost of reking, is the coreproblem of balanceable key tree for MANET multicast reking.

对于大规模自组织网络，采用完全集中式或完全分布式的组****管理的方式容易形成系统单一失效点、产生网络分割、不同步等问题，实际应用中宜采用结合集中式和分布式优点的分散式的组****管理框架，子组中心管理和用户子组管理是框架的两个管理层次，对子组中心管理关注的是组****分发的安全性和效率，如何实现分布式身份可验证的组****分发是自组织网络组****管理的关键问题。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了