检索结果-南通市图书馆

Performance Modeling and Approximate Analysis of Multiserver Multiqueue Systems with Poisson and Self-similar Arrivals

在线全文

学校读者我要写书评

暂无评论

Journal of university of Science and technology beijing 2001年第2期8卷 145-151页

作者： Zhiguang Shan, Chuang Lin, Yang Yang, Yan Wang (information engineering School, university of Science and technology beijing, beijing 100083, china. (Department of computer Science and technology, Tsinghua university, beijing 100084, china. information engineering School University of Science and Technology Beijing 100083 China

The problem of state space explosion is still ran outstanding challenge in Markovian performance analysis for multiserver multiqueue (MSMQ) systems. The system behavior of a MSMQ system is described using stochastic high-level Petri net (SHLPN) models, and an approximate performance analysis technique is proposed based on decomposition and refinement methods as well as iteration technique. A real MSMQ system, Web-server cluster, is investigated. The performance of an integrated scheme of request dispatching and scheduling is analyzed with both Poisson and self-similar request arrivals. The study shows that the approximate analysis technique significantly reduces the complexity of the model solution and is also efficient for accuracy of numerical results.

关键词： multiserver multiqueue (MSMQ) system Web-server cluster performance analysis stochastic high-level Petri net (SHLPN) request dispatching request scheduling

Optimization of Fractal Iterated Function System(IFS) with Probability and Fractal Image Generation

在线全文

学校读者我要写书评

暂无评论

Journal of university of Science and technology beijing 2001年第2期8卷 152-156页

作者： Berthe Kya, Yang Yang (information engineering School, university of Science and technology beijing, beijing 100083, china. information engineering School University of Science and Technology Beijing 100083 China

There are several methods for rendering fractal images based on IFS (Iterated Function System) in computer graphic; but one concern of the computer graphic community has been the efficiency rendering algorithms. The invariant measures arising from IFSP (Iterate Function System with Probability) using the probabilistic algorithm are also known as chaos games. The role of these probabilities to generate the image of the attractor has been investigated using a multi-fractal analysis. The conventional choice of probability associated with each set /S/ to generate the attractor in least time possible is introduced, then a new method based on the self similarity and multi-fractal analysis is presented. The efficiency of the new method has been proved over the conventional method.

关键词： optimization of fractal IFS compression IFSP multi-fractal analysis

Entropy number and non-linear approximations on multivariate Besov space by manifolds of finite pseudo-dimension

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2006年第3期16卷 260-265页

作者： LONG Jingfan and FANG Gensun (School of Mathematical Sciences, beijing Normal university, beijing 100875, china.Department of computer Science, information technology Institute, beijing 100101, china. School of Mathematical Sciences Beijing Normal University Beijing 100875 China Department of computer Science Information Technology Institute Beijing 100101 China

We determine the asymptotic order of entropy number and optimal non -linear approximations of anisotropic periodic Besov class of Bpθr(Td') (1≤p≤∞,1≤0≤∞) by manifolds of finite pseudo-dimension in the metric Lq... 详细信息

关键词： Pseudo-dimension anisotropic Besov class of functions entropy number nonlinear width.

Multiparty simultaneous quantum identity authentication with secret sharing

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.Physics,Mechanics & Astronomy) 2008年第3期51卷 321-327页

作者： YANG YuGuang1,2,WEN QiaoYan3 & ZHANG Xing4,5 1 College of computer Science and technology,beijing university of technology,beijing 100022,china.2 State Key Laboratory of information Security (Graduate university of the Chinese Academy of Sciences),beijing 100049,china.3 School of Science,beijing university of Posts and Telecommunications,beijing 100876,china.4 Institute of Electronic technology,information engineering university,Zhengzhou 450004,china.5 Trusted Computing Laboratory,beijing university of technology,beijing 100022,china College of computer Science and technology Beijing University of Technology Beijing China State Key Laboratory of information Security (Graduate university of the Chinese Academy of Sciences) Beijing China School of Science Beijing University of Posts and Telecommunications Beijing China Institute of Electronic technology Information Engineering University Zhengzhou China Trusted Computing Laboratory Beijing University of Technology Beijing China

Two multiparty simultaneous quantum identity authentication (MSQIA) protocols based on secret sharing are presented. All the users can be authenticated by a trusted third party (TTP) simultaneously. In the first protocol,the TTP shares a random key K with all the users using quantum secret sharing. The ith share acts as the authentication key of the ith user. When it is necessary to perform MSQIA,the TTP generates a random number R secretly and sends a sequence of single photons encoded with K and R to all the users. According to his share,each user performs the corresponding unitary operations on the single photon sequence sequentially. At last,the TTP can judge whether the impersonator exists. The sec-ond protocol is a modified version with a circular structure. The two protocols can be efficiently used for MSQIA in a network. They are feasible with current technol-ogy.

关键词： quantum identity authentication secret sharing quantum cryptography

Complex conforming Delaunay triangulation

在线全文

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 Science and engineering, BeiHang university, beijing 100083, china.2 School of computer Sciences, 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

A new intelligent prediction system model-the compound pyramid model

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) 2012年第3期55卷 723-736页

作者： YANG BingRu , QU Wu, WANG LiJun & ZHOU Ying School of information engineering, university of Science and technology beijing, beijing 100083, china School of information engineering University of Science and Technology Beijing

A current development trend in research on intelligent systems is to optimize a general intelligent prediction system into an individuation intelligent prediction system that is applied in specialized fields. Protein structure prediction is a challenging international issue. In this paper, we propose a new intelligent prediction system model, designed as a multi-layer compound pyramid model, for predicting secondary protein structure. The model comprises four independent intelligent interfaces and several knowledge discovery methods. The model penetrates throughout the domain knowledge, with the effective attributes chosen by Causal Cellular Automata. Furthermore, a high pure structure database is constructed for training. On the RS126 dataset, the overall state per-residue accuracy, Q3, reached 83.99%, while on the CB513 dataset, Q3 reached 85.58%. Meanwhile, on the CASP8 sequences, the results are superior to those produced by other methods, such as Psipred, Jpred, APSSP2 and BehairPred. These results confirm that our method has a strong generalization ability, and that it provides a model for the construction of other intelligent systems.

关键词： knowledge discovery intelligent prediction system model compound pyramid model

Quasi-secure quantum dialogue using single photons

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.Physics,Mechanics & Astronomy) 2007年第5期50卷 558-562页

作者： YANG YuGuang1,2 & WEN QiaoYan31 College of computer Science and technology, beijing university of technology, beijing 100022, china.2 State Key Laboratory of information Security, Graduate university of the Chinese Academy of Sciences, beijing 100049, china.3 School of Science, beijing university of Posts and Telecommunications, beijing 100876, china College of computer Science and technology Beijing University of Technology Beijing China State Key Laboratory of information Security Graduate University of the Chinese Academy of Sciences Beijing China School of Science Beijing University of Posts and Telecommunications Beijing China

A quasi-secure quantum dialogue protocol using single photons was proposed. Different from the previous entanglement-based protocols, the present protocol uses batches of single photons which run back and forth between the two parties. A round run for each photon makes the two parties each obtain a classical bit of information. So the efficiency of information transmission can be increased. The present scheme is practical and well within the present-day technology.

关键词： quantum dialogue, single photon, quantum secure direct communication

Analysis of a kind of quantum cryptographic schemes based on secret sharing

在线全文

学校读者我要写书评

暂无评论

Science china.Physics,Mechanics & Astronomy) 2009年第9期52卷 1313-1316页

作者： ZHANG XingLan1 & JI DongYao2 1 College of computer Science and technology, beijing university of technology, beijing 100124, china.2 State Key Laboratory of information Security, Graduate university of Chinese Academy of Sciences, beijing 100049, china College of computer Science and technology Beijing University of Technology Beijing China State Key Laboratory of information Security Graduate University of Chinese Academy of Sciences Beijing China

Recently, Yang et al. proposed a kind of quantum cryptographic schemes based on secret sharing. The main idea is drawn from the case, where any n participants who share a secret K can co-operate as K does. This process can be applied to encryption, authentication, signature and so on. Unfortunately, since there is no identity authentication of the share's holder, these schemes inherit the limitation of secret sharing in practice. If some participants do not follow the protocol, the protocol would be a failure at last. Moreover, these schemes encounter another serious attack. Any two participants can co-operate to defeat the schemes by sending different shares to the parties unknown to the distributor of the secret K, such that these parties can execute the protocol as well. The attack proves that it is not enough for quantum cryptographic schemes that only the secret key is secure.

关键词： quantum identity authentication quantum secure direct communication quantum signature secret sharing

Threshold quantum secure direct communication without entanglement

在线全文

学校读者我要写书评

暂无评论

Science china.Physics,Mechanics & Astronomy) 2008年第2期51卷 176-183页

作者： YANG YuGuang1,3 & WEN QiaoYan2 1 College of computer Science and technology, beijing university of technology, beijing 100022, china.2 School of Science, beijing university of Posts and Telecommunications, beijing 100876, china.3 State Key Laboratory of information Security (Graduate School of Chinese Academy of Sciences), beijing 100049, china College of computer Science and technology Beijing University of Technology Beijing China State Key Laboratory of information Security (Graduate School of Chinese Academy of Sciences) Beijing China School of Science Beijing University of Posts and Telecommunications Beijing China

For the first time, a threshold quantum secure direct communication (TQSDC) scheme is presented. Similar to the classical Shamir's secret sharing scheme, the sender makes n shares, S1, …, Sn of secret key K and each receiver keeps a share secretly. If the sender wants to send a secret message M to the receivers, he en-codes the information of K and M on a single photon sequence and sends it to one of the receivers. According to the secret shares, the t receivers sequentially per-form the corresponding unitary operations on the single photon sequence and ob-tain the secret message M. The shared shares may be reusable if it can be judged that there is no eavesdropper in line. We discuss that our protocol is feasible with current technology.

关键词： quantum secure direct communication threshold secure direct communication quantum secret sharing