并行数据包采集代理系统中的故障检测与恢复

在基于网络的IDS中，并行多采集代理技术可以有效地降低系统丢包率，但这种并行结构也造成了系统的可靠性下降。为了提高系组统可靠性．给出了并行采集代理的故障模型，针对并行采集代理中包选择算法的特点和并行采集所应用的环境，提出了基于检测代理和基于故障状态广播的两种故障检测与恢复模型，并分析了两者各自的优势和适用范围。最后定量给出了系统性能和可靠性之间的关系     

TTFS:一个倾向性文本过滤系统的设计与实现

以往文本过滤的研究主要集中于主题性过滤，然而随着网络的发展，倾向性文本过滤在网络信息安全方面的作用越来越大。论文阐述了一个倾向性文本过滤系统TTFS(Tenclency Text Filtering System)，能够对具有关于某个主题的特定倾向的文本进行过滤。该系统充分利用了领域知识，采用了语义模式分析等技术，实验表明其查全率和查准率高，速度较快。     

基于SCORE结构的QoS模型实现算法

根据在核心路由器不保留每一个流的状态的SCORE(可扩展核心式)网络结构的特点,在文中,提出了两个分布式算法来实现QoS列表和接纳控制。它显著地提高了在数据平面和控制平面的可扩展性,在灵活性、利用率和服务保证的水平方面提供了可保证的服务,接近提供每一个流的状态的保证型服务。     

未来光传送网核心技术展望

介绍光传送网技术的发展历程和现状，简述光传送网技术发展的一些观点，展望未来光传送网发展的核心技术。     

Routing on Meshes with Buses

We consider the problem of routing packets on an MIMD mesh-connected array of processors augmented with row and column buses. We give lower bounds and randomized algorithms for the problem of routing k-permutations (where each processor is the source and destination of exactly k packets) on a d-dimensional mesh with buses, which we call the (k,d)-routing problem. We give a general class of ``hard' permutations which we use to prove lower bounds for the (k,d)-routing problem, for all k,d≥ 1. For the (1,1)- and (1,2)-routing problems the worst-case permutations from this class are identical to ones published by other authors, as are the resulting lower bounds. However, we further show that the (1,d)-routing problem requires 0.72 ... n steps for d=3, 0.76 ... n steps for d=4, and slightly more than steps for all d≥ 5. We also obtain new lower bounds for the (k,d)-routing problem for k,d > 1, which improve on the bisection lower bound in some cases. These lower bounds hold for off-line routing as well. We develop efficient algorithms for the (k,1)-routing problem and for the problem of routing k-randomizations (where each processor has k packets initially and each packet is routed to a random destination) on the one-dimensional mesh and use them in a general (k,d)-routing algorithm which improves considerably on previous results. In particular, the routing time for the (1,d)-routing problem is bounded by steps with high probability (whp), whenever for some constant ε > 0, and the routing time for the (k,d)-routing problem is steps whp whenever for some constant ε > 0 and k≥ 3.6 ... d, matching the bisection lower bound. We then present a simple algorithm for the (2,2)-routing problem running in 1.39 ... n+o(n) steps whp. Finally, for the important special case of routing permutations on two-dimensional meshes with buses, the (1,2)-routing problem, we give a more sophisticated algorithm that runs in 0.78 ... n+o(n) steps whp. Received May 18, 1994; revised June 23, 1995.     

Rendering Caustics on Non-Lambertian Surfaces

This paper presents a new technique for rendering caustics on non-Lambertian surfaces. The method is based on an extension of the photon map which removes previous restrictions limiting the usage to Lambertian surfaces. We add information about the incoming direction to the photons and this allows us to combine the photon map with arbitrary reflectance functions. By using a cone-filter we improve the quality of the radiance estimate in particular at discontinuities. Furthermore we introduce balancing of the photon map which not only reduces the memory requirements but also significantly reduces the rendering time. We have used the method to render caustics on surfaces with reflectance functions varying from Lambertian to glossy specular.     

基于应用网关的防火墙安全系统的设计与实现

文中给出了一和中基于应用网关的防火墙安全系统的设计与实现的方法。重点介绍了系统安全策略以及所采用的分组滤波，基于ＩＰ层的 密这两种主要技术。     

RPR在浙江江山供电局的应用

弹性分组环(RPR)是一种新的MAC层协议,是为优化数据包的传输而提出的技术,融合了现有以太网和SDH的技术优势,十分适合宽带接入网建设。文章以江山供电局兴建的RPR网络为议题,在介绍了美国络明公司RPR系统(本网主要设备)可提供的EPL、TPL、TLS等多个网络应用服务之后,着重讨论了江山供电局是如何根据RPR的不同业务目标,灵活选择上述不同的服务内容,构建数据网络;以及如何根据市场的发展变化,优化完善这些运行业务的。     

电力通信系统中的SDH自愈环组网及其应用探讨

SDH环形网络因其具有自愈能力的优点,常常用于电力系统中继网和重要的长途骨干网的建设,因而如何更好地解决环网的安全性问题则至关重要。文章简要介绍了基于SDH传输机制的自愈环保护系统,包括基本概念、工作原理、性能比较以及应用范围。具体阐述了SDH自愈环组网应用中存在的一些实际问题,并探讨了相应的技术措施和解决方法。     

一种适于多维的快速包分类算法

包分类是多种网络应用的关键性技术，包分类算法的性能对网络的时延和吞吐量有决定性的影响。文章介绍一种适于多维的快速包分类算法——RFC算法，论述了算法的原理和实现算法，将RFC算法与几种常见的分类算法作仿真比较，阐述了RFC算法的优越性。