检索结果-南通市图书馆

Complex conforming Delaunay triangulation

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

science china(Information sciences) 2010年第6期53卷 1130-1140页

作者： MENG XianHai 1, LI JiGang 1, YANG Qin 1, CAI Qiang 2.& CHEN QiMing 3 1 NLSDE, School of computer {2. and engineering, BeiHang University, Beijing 100083, china 2.School of computer {2.s, Beijing Technology and Business University, Beijing 100037, china 3 School of Mechanical engineering and Automation, BeiHang University, Beijing 100083, china NLSDE School of Computer Science and Engineering BeiHang University

A novel algorithm of conforming Delaunay triangulation for curved geometry is presented in the paper.A progress has been made for the problem puzzled Delaunay refinement where curved constraints cannot be accepted as input *** algorithm is based on a new sufficient condition for the existence of constraints in *** requires computing only the intersection between constraints and Voronoi edges or faces instead of the circum-sphere of curved *** the termination of the algorithm when small input angles exist in constraints, a weighted method is applied to ensure that the algorithm can terminate under any *** two-dimensional and three-dimensional results are also *** is shown that the algorithm has the capability of dealing with both linear and nonlinear constraints in a consistent way, without the need of maintaining triangular meshes on face constraints.

关键词： mesh generation Delaunay triangulation conforming curved constraints tetrahedralization weight

基于粒子群优化的ad hoc网络最小能耗多播路由算法

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

通信学报 2012年第3期33卷 52-58页

作者：朱晓建沈军东南大学计算机科学与工程学院江苏南京211189 东南大学计算机网络和信息集成教育部重点实验室江苏南京211189

在无线ad hoc网络中,设备使用电池提供能量,随着多播应用日益广泛,如何构造最小能耗多播树是一个重要问题。针对选择不同的中继节点集对构造最小能耗多播树的影响,提出了一种优化最小能耗多播树构造的离散粒子群算法。为了避免离散粒子... 详细信息

在无线ad hoc网络中,设备使用电池提供能量,随着多播应用日益广泛,如何构造最小能耗多播树是一个重要问题。针对选择不同的中继节点集对构造最小能耗多播树的影响,提出了一种优化最小能耗多播树构造的离散粒子群算法。为了避免离散粒子群算法早熟收敛,引入惯性权重策略,以平衡算法的全局搜索能力和局部搜索能力。模拟实验结果表明改进后的离散粒子群算法具有较强的优化能力,有效地优化了最小能耗多播树的构造。

关键词：无线adhoc网络多播路由最小能耗粒子群优化

Group sparse representation for image categorization and semantic video retrieval

在线全文

学校读者我要写书评

暂无评论

science china(Information sciences) 2011年第10期54卷 2051-2063页

作者： LIU YaNan 1,2.,WU Fei 2.& ZHUANG YueTing 2.1 School of Information,Zhejiang University of Finance & Economics,Hangzhou,310018,china 2.College of {2. science and Technology,Zhejiang University,Hangzhou,310012.china School of Information Zhejiang University of Finance & Economics College of computer science and Technology Zhejiang University

Multimedia content analysis and management are a promising and challenging *** this paper we develop a novel approach to image representation,which we call group sparse representation (GSR),for image classification and video *** basic idea is to represent a test image as a weighted combination of all the training *** particular,we introduce two sets of weight coefficients,one for each training image and the other for each ***,we formulate our concern as a group nonnegative garrote *** resulting representations are sparse,and they are appropriate for discriminant *** on Caltech101 and PASCAL VOC2.08 image dataset and TRECVID2.05 video corpus testify that our proposed approach is efficient and effective.

关键词： compressive sensing group sparse representation bag-of-SIFT-words nonnegative garrote l1-minimization apcluster

Study on An Absolute Non-Collision Hash and Jumping Table IP Classification Algorithms

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Wuhan University Journal of Natural sciences 2004年第5期9卷 835-838页

作者： SHANG Feng-jun 1,2.,PAN Ying-jun 1 1. Key Laboratory of Opto-Electronic Technology and System of Ministry of Education/College of Opto-Electronic engineering,Chongqing University, Chongqing 400044,china 2. College of {2. science and Technology, Chongqing University of Posts and Telecommunications, Chongqing 400065,china Key Laboratory of Opto-Electronic Technology and System of Ministry of Education/College of Opto-Electronic engineering Chongqing University Chongqing China College of computer science and Technology Chongqing University of Posts and Telecommunications Chongqing China

In order to classify packet, we propose a novel IP classification based the non-collision hash and jumping table trie-tree (NHJTTT) algorithm, which is based on noncollision hash Trie-tree and Lakshman and Stiliadis proposing a 2.dimensional classification algorithm (LS algorithm). The core of algorithm consists of two parts: structure the non-collision hash function, which is constructed mainly based on destination/source port and protocol type field so that the hash function can avoid space explosion problem; introduce jumping table Trie-tree based LS algorithm in order to reduce time complexity. The test results show that the classification rate of NHJTTT algorithm is up to 1 million packets per second and the maximum memory consumed is 9 MB for 10 000 rules. Key words IP classification - lookup algorithm - trie-tree - non-collision hash - jumping table CLC number TN 393.06 Foundation item: Supported by the Chongqing of Posts and Telecommunications Younger Teacher Fundation (A2.03-03).Biography: SHANG Feng-jun (1972.), male, Ph.D. candidate, lecture, research direction: the smart instrument and network.

关键词： IP classification lookup algorithm trie-tree non-collision hash jumping table

A general communication performance evaluation model based on routing path decomposition

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-science C(computers and Electronics) 2011年第7期12卷 561-573页

作者： Ai-lian CHENG 1,Yun PAN 1,2.Xiao-lang YAN 2.Ruo-hong HUAN 3 (1 Department of Information science and Electronic engineering,Zhejiang University,Hangzhou 31002.,{2.) (2.Institute of VLSI Design,Zhejiang University,Hangzhou 31002.,{2.) (3 College of computer science and Technology,Zhejiang University of Technology,Hangzhou 31002.,{2.) Department of Information science and Electronic engineering Zhejiang University Institute of VLSI Design Zhejiang University

The network-on-chip (NoC) architecture is a main factor affecting the system performance of complicated multi-processor systems-on-chips (MPSoCs).To evaluate the effects of the NoC architectures on communication efficiency,several kinds of techniques have been developed,including various simulators and analytical *** simulators are accurate but time consuming,especially in large space explorations of diverse network configurations;in contrast,the analytical models are fast and flexible,providing alternative methods for performance *** this paper,we propose a general analytical model to esti-mate the communication performance for arbitrary NoCs with wormhole routing and virtual channel flow *** resolve the inherent dependency of successive links occupied by one packet in wormhole routing,we propose the routing path decomposition approach to generating a series of ordered link *** we use the traditional queuing system to derive the fine-grained transmission latency for each network *** to our experiments,the proposed analytical model provides a good approximation of the average packet latency to the simulation results,and estimates the network throughput precisely under various NoC configurations and ***,the analytical model runs about 10 5 times faster than the cycle-accurate NoC *** applications of the model including bottleneck detection and virtual channel allocation are also presented.

关键词： Analytical model Communication performance Network-on-chip (NoC) Queuing system Routing path decom-position Virtual channel

Towards a Methodology for Formal Design and Analysis of Agent Interaction Protocols ——An Investigation in Electronic Commerce

在线全文

学校读者我要写书评

暂无评论

Wuhan University Journal of Natural sciences 2001年第Z1期6卷 126-139页

作者： Wei Jun 1,2., Cheung Shing Chi 1, Wang Xu 1 1. Department of computer science, Hong Kong University of science and Technology, Clear Water Bay, Kowloon, Hong Kong, china 2. Institute of Software, Chinese Academy of science, Beijing 100080, Ch Department of computer science Hong Kong University of Science and Technology Kowloon Hong Kong China Institute of Software Chinese Academy of Science Beijing China

Various extensions of UML have been developed to meet the challenges of designing modern software systems, such as agent based electronic commerce applications. Recent advances in model checking technology have led it to be introduced into the development of approaches and tools to check the correctness of electronic commerce protocols. This paper focuses on the research of a method that connects an extension of AUML to model checker SPIN/Promela for the specification and verification of agent interaction protocols (AIP) in electronic commerce. The method presented here allows us to combine the benefits of visual specification with the power of some static analysis and model checking. Some algorithms and rules are developed to permit all visual modeling constructs translated mechanically into some Promela models of AIP, as supported by the model checker SPIN. Moreover, a process is illustrated to guide the specification and verification of AIP. The method is demonstrated thoroughly using the e commerce protocol NetBill as an example.

关键词： agent UML interaction protocol software agent model checking formal specification electronic commerce protocol

Bayesian cognitive trust model based self-clustering algorithm for MANETs

在线全文

学校读者我要写书评

暂无评论

science china(Information sciences) 2010年第3期53卷 494-505页

作者： WANG Wei1,2.3 & ZENG GuoSun1,2.31Department of computer science & Technology, Tongji University, Shanghai 2.0092. {2. 2.ongji Branch, National engineering & Technology Center of High Performance computer, Shanghai 2.0092. {2. 3Key Loboratory of Embedded System and Service Computing, Ministry of Education, Shanghai 2.0092. {2. Department of computer science & Technology Tongji University Tongji Branch National Engineering & Technology Center of High Performance Computer Key Loboratory of Embedded System and Service Computing Ministry of Education

With the introduction of mobile Ad hoc networks (MANETs), nodes are able to participate in a dynamic network which lacks an underlying infrastructure. Before two nodes agree to interact, they must trust that each will satisfy the security and privacy requirements of the other. In this paper, using the cognition inspired method from the brain informatics (BI), we present a novel approach to improving the search efficiency and scalability of MANETs by clustering nodes based on cognitive trust mechanism. The trust relationship is formed by evaluating the level of trust using Bayesian statistic analysis, and clusters can be formed and maintained autonomously by nodes with only partial knowledge. Simulation experiments show that each node can form and join proper clusters, which improve the interaction performance of the entire network. The essence of the underlying reason is analyzed through the theory of complex networks, revealing great scalability of this method.

关键词： trust model MANET self-clustering Bayesian method cognitive mobile

Online approach to feature interaction problems in middleware based system

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

science in china(Series F) 2008年第3期51卷 225-239页

作者： HUANG Gang1,2.LIU XuanZhe1,2.& MEI Hong1,2.1 Key Laboratory of High Confidence Software Technologies, Ministry of Education, Peking University, Beijing 1000871, china 2.School of Electronics {2. and computer science, Peking University, Beijing 100871, china Key Laboratory of High Confidence Software Technologies Ministry of Education Peking University School of Electronics engineering and {2. science Peking University

As a popular infrastructure for distributed systems running on the Internet, middleware has to support much more diverse and complex interactions for coping with the drastically increasing demand on information technology and the extremely open and dynamic nature of the Internet. These supporting mechanisms facilitate the development, deployment, and integration of distributed systems, as well as increase the occasions for distributed systems to interact in an undesired way. The undesired interactions may cause serious problems, such as quality violation, function loss, and even system crash. In this paper, the problem is studied from the perspective of the feature interaction problem （FIP） in telecom, and an online approach to the detection and solution on runtime systems is proposed. Based on a classification of middleware enabled interactions, the existence of FIP in middleware based systems is illustrated by four real cases and a conceptual comparison between middleware based systems and telecom systems. After that, runtime software architecture is employed to facilitate the online detection and solution of FIP. The approach is demonstrated on J2.E （Java 2.Platform Enterprise Edition） and applied to detect and resolve all of the four real cases.

关键词： feature interaction middleware reflective software architecture

Self-healing routing: failure,modeling and analysis

在线全文

学校读者我要写书评

暂无评论

science china(Information sciences) 2011年第3期54卷 609-622页

作者： XU MingWei 1,2., LI Qi 1,2., YANG Yuan 1,2., HOU MeiJia 1,2.& PAN LingTao 1,2.1 Department of computer science, Tsinghua University, Beijing 100084, {2. 2.Tsinghua National Laboratory for Information science and Technology (TNList), Beijing 100084, {2. Department of computer science Tsinghua University Tsinghua National Laboratory for Information science and Technology (TNList)

Network failures occur frequently, and self-healing ability of existing routing protocols cannot guarantee fast route convergence under these failures without impacting packet forwarding. During routing convergence, network routes may be incorrect and even routing black holes and loops occur, which will result in extensive packet loss and thus influence network performance. To solve this problem, several improved routing solutions have been proposed. In this paper, we propose the concept and model of self-healing routing and analyze the key problems in current intra-domain and inter-domain self-healing routing protocols after briefly reviewing the characteristics of network failures. We classify the different self-healing solutions into two categories based on their design principles: routing restoration and routing protection, and systematically analyze these different typical solutions. Finally, we discuss several key issues in self-healing routing and propose a hybrid protection and restoration based routing scheme.

关键词： failure intra-domain routing inter-domain routing self-healing routing