利用访问控制列表提高网络安全及实例

本文以cisco路由器为例，结合实际网络结构，详细介绍了如何利用访问控制列表来提高网络安全性能。     

Geometry of single axis motions using conic fitting

Previous algorithms for recovering 3D geometry from an uncalibrated image sequence of a single axis motion of unknown rotation angles are mainly based on the computation of two-view fundamental matrices and three-view trifocal tensors. We propose three new methods that are based on fitting a conic locus to corresponding image points over multiple views. The main advantage is that determining only five parameters of a conic from one corresponding point over at least five views is simpler and more robust than determining a fundamental matrix from two views or a trifocal tensor from three views. It is shown that the geometry of single axis motion can be recovered either by computing one conic locus and one fundamental matrix or by computing at least two conic loci. A maximum likelihood solution based on this parametrization of the single axis motion is also described for optimal estimation using three or more loci. The experiments on real image sequences demonstrate the simplicity, accuracy, and robustness of the new methods.     

Allocating Network Resources by Weight Between TCP Traffics

Under the current TCP/IP architecture,all TCP traffics compete for network resources completely fairly,which makes it difficult to satisfy applications‘‘‘‘‘‘‘‘ versatile communication requirements.This paper presents an improved TCP congestion control mechanism where the congestion window becomes ω(1-b)W rather than(1-b)W for every window W containing a packet loss.Theoretical analysis and simulation results show that it cann be easily implemented with less additional overhead and can easily perform network resource allocation by weighted parameter ω for traffics under the similar communication environments,whic can efficiently lead to guaranteed relative quqlity of scrviccs and improve network performances.     

多层分布式结构应用系统的维护

本文介绍了多层分布式结构及其优点，着重从事务交易管理、安全服务 以及容错能力和负载平衡等方面，去阐述维护多层分布式应用系统稳定性、安全性的必要性和有效途径。     

基于Wigner滤波的配准图去噪应用研究

在景象匹配应用中,由于景象配准图受到各种随机噪声的干扰,致使匹配精度下降。滤波技术可以滤除噪声,还原图象。但是,因为干扰噪声的数学模型难以准确确定,所以去噪效果不佳。该文提出了一种自适应Wigner滤波方法,它根据图象块的统计特性来估计误差噪声,以被滤除的误差信息作为控制变量,用来改变Wigner滤波器的结构,提高去噪能力。     

CT-6B托卡马克的交流运行实验研究

在CT—6B托卡马克上首次实现了多周期交流运行，对多个周期中等离子体进行比较发现，尽管在每个周期的两个半周中等离子体与壁的相互作用有所不同，但等离子体中的杂质积累并未受到严重影响。通过内磁探针测量了等离子体电流密度的分布，发现等离子体电流首先从弱场区开始反相，电流反相过零时同时存在正负局部等离子体电流，此时的磁面结构有效地约束了粒子。     

Fabrication of thick BOX SOI by Smart-cut technology

A SOI material with thick BOX (2.2 μm) was successfully fabricated using the Smart-cut technology. The thick BOX SOI microstructures were investigated by high resolution cross-sectional transmission electron mi-croscopy (XTEM), while the electrical properties were studied by the spreading resistance profile (SRP). Experimen-tal results demonstrate that both structural and electrical properties of the SOI structure are very good.     

XML文档的相似测度和结构索引研究

提出了一个可用于定量度量XML文档间差异的方法(称为XED距离)。利用结点间的模拟关系，一个XML文档可以表示为一棵精简的、带权重的结构索引树，两个XML文档间的相似度可以通过计算它们的索引树间的编辑距离来测定，利用索引树可以大大提高判定两个XML文档结构相似度的效率，XED距离测度可用于XML文档的结构搜索、XML文档聚类、XML文档结构抽取、XML文档的变换检测以及XML视图的增量计算和维护等。     

基于SIMD—PRAM模型的分块图像匹配算法设计

该文研究了基于SIMD—PRAM计算模型的有限处理元阵列规模的并行计算算法设计,分析了求阵列和的并行算法性能,运用求阵列和、图像分块映射与四邻平移等方法提出了一种根据处理元局部可用资源进行分块计算的图像匹配算法。计算机模拟实验结果表明,该算法完整、高效地执行了图像匹配,具有良好的并行计算性能。     

基于聚类和分类的自学习系统模型

论文在分析聚类与分类方法的基础上,尝试将这两种独立的开采方法集成起来,使两种开采方法能够相得益彰。由此建立的知识发现系统能自动利用已有知识进行分类,同时可较为准确地估计聚类分析所必需的参数,并通过聚类分析来发现和修正错误知识。论文给出了集成方法和实验结果,最后对该集成算法的性能进行了分析。