基于移动代理的网格计算环境下的资源管理的研究

根据网格计算环境的各种特点,分析比较了网格计算环境下各种资源调度模型,得出采用分布式资源调度的体系结构和基于移动代理的资源管理策略的可行性和必要性.论述了在网格计算环境下引入移动代理技术对于解决网格计算问题的作用和优点,提出了基于移动代理的资源管理模型,并分析了在此系统中采用的资源发现算法及资源调度策略.     

Wavelet analysis method for detection of DDoS attack on the basis of Self-similarity

As the traditional methods were not suitable for the detection of small distribute denial of service (DDoS) attack and identification of busy traffic, on the basis of the influence of DDoS attack, one wavelet analysis method was proposed. Wavelet method of coefficient variance analysis was deduced and a software model for the method was designed. In addition, key issues of the choice of wavelet and calculation of Hurst were resolved. The experimental results show that the proposed method has more advantages in accurately identifying busy traffic and detection of small DDoS attack. Translated from Journal on Communications, 2006, 27(5): 6–11 [译自: 通信学报]     

基于网格的现代远程教育系统模型的研究与实现

随着网格技术的发展和日渐成熟,提高远程教育效果的一个重要问题,就是在此基础上依据网格技术和现代通信技术建立一个实时远程教育系统.文中分析了网格计算技术的特点,提出基于网格的现代远程教育系统模型(GEM).最后讨论了GEM的实现方法.     

Localization algorithm based on minimum condition number for wireless sensor networks

During range-based self-localization of Wireless Sensor Network (WSN) nodes, the number and placement methods of beacon nodes have a great influence on the accuracy of localization. This paper proves a theorem which describes the relationship between the placement of beacon nodes and whether the node can be located in 3D indoor environment. In fact, as the highest locating accuracy can be acquired when the beacon nodes form one or more equilateral triangles in 2D plane, we generalizes this conclusion to 3D space, and proposes a beacon nodes selection algorithm based on the minimum condition number to get the higher locating accuracy, which can minimize the influence of distance measurement error. Simulation results show that the algorithm is effective and feasible.     

基于极端途径的生化网络模块化分析

近年来,对于复杂生化网络系统进行模块化分析引起了科研人员的极大关注。一般认为,模块化分析有助于理解这些网络的结构与功能关系。但是,当前的模块化分析方法大多将生化网络考虑为普通的复杂网络,所得模块的生物学意义较低。介绍了化学计量矩阵及极端途径分析等基本概念,对苏云金杆菌的丁醇代谢系统进行建模分析,研究结果表明：极端途径分析可用于识别网络中的功能模块,具备较好的生物学意义。     

基于链接聚类的代谢网络社团结构研究

社团结构分析有助于识别代谢网络中的功能模块,有助于理解代谢网络的结构和功能关系,是代谢网络研究领域的一个重要研究课题。然而,当前的社团结构分析方法均依赖于对网络中的节点进行聚类分析,导致每个节点只能属于某一个社团。采用了一种对复杂网络中的链接进行聚类分析的方法,对高质量金黄色葡萄球菌代谢网络模型的巨强连通体进行了社团结构分析,得到了10个具有生物学意义的功能模块,结果表明链接聚类可用于识别新陈代谢网络中的功能社团。     

Real-Time Method for DDoS Attacks Detection Based on Self-Similarity and Wavelet Analysis

Traditional wavelet methods are not efficient to detect the real-time traffic anomaly. To address this drawback, on the basis of self-similarity and wavelet analysis, this paper proposes one real-time method for DDoS attacks detection. Firstly, to effectively analyze new network state, we extracted data packets from network monitor in backward time direction. Secondly, for reducing admissible computing time, we applied time scale selfadjust according to last packets arrival speed. Finally, we adopted three parallel computing strategies to improve real-time performance. Experimental results show that proposed method can quickly and accurately detect DDoS attacks.     

一种面向无线多媒体传感器网络的分布式图像压缩算法

因为多媒体数据的高带宽要求,要传输传感器节点采集到的原始数据将会消耗大量的资源。文章提出了一种分布式图像压缩算法,该算法通过把压缩任务分配给其他节点来解决在能量受限的节点上处理能力不足的问题。此外,该算法把压缩任务分配给其他空闲节点能很好的延长网络的生存时间。     

移动代理安全机制的研究

移动代理的安全性成为了移动代理系统在Internet及其它现代网络技术中推广应用的瓶颈。论文详细分析了移动代理系统中在数据传递和通信链接、服务器系统资源、移动代理运行环境以及移动代理自身安全等方面存在的种种安全威胁和隐患。然后分别对传输中的移动代理、服务器资源、执行环境中移动代理的保护方案进行了系统的研究,创造性地将JavaCard技术用于构建安全的移动代理执行环境。并在此研究成果基础之上设计并开发出SMMA2002移动代理安全模型系统。