检索结果-南通市图书馆

Grey Markov chain and its application in drift prediction model of FOGs

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Systems engineering and Electronics 2005年第2期16卷 388-393页

作者： Fan Chunling 1,2., Jin Zhihua1, Tian Weifeng1 & Qian Feng11. department of Information Measurement Technology and Instrument, shanghai {2. University,shanghai 2.0030, P. R. china 2. College of Automation and Electric engineering, Qingdao University of science and Technology,Qingdao 2.6042. P. R. china department of Information Measurement Technology and Instrument Shanghai Jiaotong University Shanghai 200030 P. R. China College of Automation and Electric engineering Qingdao University of Science and Technology Qingdao 266042 P. R. China

A novel grey Markov chain predictive model is discussed to reduce drift influence on the output of fiber optical gyroscopes (FOGs) and to improve FOGs' measurement precision. The proposed method possesses advantages of grey model and Markov chain. It makes good use of dynamic modeling idea of the grey model to predict general trend of original data. Then according to the trend, states are divided so that it can overcome the disadvantage of high computational cost of state transition probability matrix in Markov chain. Moreover, the presented approach expands the applied scope of the grey model and makes it be fit for prediction of random data with bigger fluctuation. The numerical results of real drift data from a certain type FOG verify the effectiveness of the proposed grey Markov chain model powerfully. The Markov chain is also investigated to provide a comparison with the grey Markov chain model. It is shown that the hybrid grey Markov chain prediction model has higher modeling precision than Markov chain itself, which prove this proposed method is very applicable and effective.

关键词： grey model Markov chain FOG drift.

Constructing Product Ontologies with an Improved Conceptual Clustering Algorithm

在线全文

学校读者我要写书评

暂无评论

Journal of Systems engineering and Electronics 2002年第3期13卷 71-77页

作者： Cao Dajun & Xu Liangxian department of computer {2., shanghai jiaotong University, shanghai 2.0030, P.R. china department of computer {2. Shanghai Jiaotong University Shanghai 200030 P. R. China

In a distributed eMarketplace, recommended product ontologies are required for trading between buyers and sellers. Conceptual clustering can be employed to build dynamic recommended product ontologies. Traditional methods of conceptual clustering (e.g. COBWEB or Cluster/2. do not take heterogeneous attributes of a concept into account. Moreover, the result of these methods is clusters other than recommended concepts. A center recommendation clustering algorithm is provided. According to the values of heterogeneous attributes, recommended product names can be selected at the clusters, which are produced by this algorithm. This algorithm can also create the hierarchical relations between product names. The definitions of product names given by all participants are collected in a distributed eMarketplace. Recommended product ontologies are built. These ontologies include relations and definitions of product names, which come from different participants in the distributed eMarketplace. Finally a case is given to illustrate this method. The result shows that this method is feasible.

关键词： Machine learning Conceptual clustering Product ontologies Electronic marketplace.

STUDY ON SINGULAR CONFIGURATIONS AND computer SIMULATION OF 6R ROBOT

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical engineering 2004年第2期17卷 177-180页

作者： Zhang Kai Hu Dejin Liu Chengliang School of Mechanical engineering,shanghai {2. University,shanghai 2.0030, china School of Mechanical engineering Shanghai Jiaotong University 上海 200030

When robot is at singular configuration, the limited hand velocity wouldrequire some joints with infeasible speeds so as to lead unsafely of the system. A method of solvingthe approximate velocity of joint near singular configuration point by adding damped vector isproposed and a modified algorithm is provided. With the analysis of J^(-1) the singularconfigurations of 6R robot are divided into structure boundary singularity , boundary singularity ,inner singularity and wrist singularity. The conditions of singularities of the robot have beenascertained. The computer simulations of the singularities of the robot are developed, which havemany advantages over previous description methods of the singular configurations of robot. With thehelp of boundary singularity analysis, a application in welding trajectory planning checking of therobot has been carried out and the simulation result proved visualized and useful.

关键词： Robot Singular configuration computer simulation

Pseudo-Random Sequences Generator Based on Discrete Hyperchaotic Systems

在线全文

学校读者我要写书评

暂无评论

Journal of Systems engineering and Electronics 2003年第4期14卷 84-89页

作者： Li Changgang & Han Zhengzhi department of Automation, shanghai {2. University, shanghai 2.0030, P. R. china department of Automation Shanghai Jiaotong University Shanghai 200030 P. R. China

We first design a discrete hyperchaotic system via piece-wise linear state feedback. The states of the closed loop system are locally expanding in two directions but absolutely bounded on the whole, which implies hyperchaos. Then, we use three suchlike hyperchaotic systems with different feedback gain matrices to design a pseudo-random sequence generator (PRSG). Through a threshold function, three sub-sequences generated from the output of piecewise linear functions are changed into 0-1 sequences. Then, followed by XOR operation, an unpredictable pseudo-random sequence (PRS) is ultimately obtained. The analysis and simulation results indicate that the PRS, generated with hyperchaotic systems, has desirable statistical features.

关键词： discrete hyperchaotic system piecewise linear state feedback pseudo-random sequences.

Stability analysis of cellular neural networks with time-varying delay

在线全文

学校读者我要写书评

暂无评论

Journal of Systems engineering and Electronics 2009年第2期20卷 266-273页

作者： Wang Xingang1,4, Zhang Dongmei2.& Liu Jun3 1. Coll. of Information engineering, Zhejiang Univ. of Technology, Hangzhou 310032. P. R. china 2. Coll. of {2., Zhejiang Univ. of Technology, Hangzhou 310032. P. R. china 3. Coll. of {2., Beihua Univ., Jilin 132.00, P. R. china 4. School of computer engineering and {2., shanghai Univ., shanghai 2.0072. P. R. china Coll. of Information engineering Zhejiang Univ. of Technology Hangzhou 310032 P. R. China School of computer engineering and {2. Shanghai Univ. Shanghai 200072 P. R. China Coll. of science Zhejiang Univ. of Technology Hangzhou 310032 P. R. China Coll. of science Beihua Univ. Jilin 132000 P. R. China

The global asymptotic stability of cellular neural networks with delays is investigated. Three kinds of time delays have been considered. New delay-dependent stability criteria are proposed and are formulated as the feasibility of some linear matrix inequalities, which can be checked easily by resorting to the recently developed interior-point algorithms. Based on the Finsler Lemma, it is theoretically proved that the proposed stability criteria are less conservative than some existing results.

关键词： cellular neural networks time-varying delay integral inequality

Forecasting of Stock Returns by Using Manifold Wavelet Support Vector Machine

在线全文

学校读者我要写书评

暂无评论

Journal of shanghai jiaotong university({2.) 2010年第1期15卷 49-53页

作者：汤凌冰盛焕烨汤凌霄 department of computer {2. and engineering Shanghai Jiaotong University department of computer and Electronic {2. Hunan Business College School of Economics Changsha University of Science & Technology

An admissible manifold wavelet kernel is proposed to construct manifold wavelet support vector machine(MWSVM) for stock returns *** manifold wavelet kernel is obtained by incorporating manifold theory into wavelet technique in support vector machine(SVM).Since manifold wavelet function can yield features that describe of the stock time series both at various locations and at varying time granularities,the MWSVM can approximate arbitrary nonlinear functions and forecast stock returns *** applicability and validity of MWSVM for stock returns forecasting is confirmed through experiments on real-world stock data.

关键词： stock returns forecasting kernel manifold wavelet support vector machine (MWSVM)

Universally Composable Proactive Threshold RSA Signature

在线全文

学校读者我要写书评

暂无评论

Journal of shanghai jiaotong university({2.) 2008年第6期13卷 659-663页

作者：洪璇陈克非龙宇 computer science and {2. department shanghai jiaotong University Shanghai 200240China

Recently some efforts were made towards capturing the security requirements within the composable security framework. This modeling has some significant advantages in designing and analyzing complex systems. The threshold signature was discussed and a definition was given based on the universal composability framework, which is proved to be equivalent to the standard security definition. Furthermore, a simple, efficient and proactive threshold RSA signature protocol was presented. It is proved to be correct, consistent and unforgeable relative to the environment that at most t - 1 parties are corrupted in each proactive stage. It is also secure under the universal composability framework. It is a UC based security and is proved to be equivalent to the standard security.

关键词： proactiveness RSA threshold signature universal composability framework

A Probability Approach to Anomaly Detection with Twin Support Vector Machines

在线全文

学校读者我要写书评

暂无评论

Journal of shanghai jiaotong university({2.) 2010年第4期15卷 385-391页

作者：聂巍何迪 department of Electronic engineering Shanghai Jiaotong University

Classification of intrusion attacks and normal network flow is a critical and challenging issue in network security study. Many intelligent intrusion detection models are proposed, but their performances and efficiencies are not satisfied to real computer networks. This paper presents a novel effective intrusion detection system based on statistic reference model and twin support vector machines （TWSVMs）. Moreover, a network flow feature selection procedure has been studied and implemented with TWSVMs. The performances of proposed system are evaluated through using the fifth international conference on knowledge discovery and data mining in 1999 （KDD＇99） data set collected at MIT＇s Lincoln Labs and the results indicate that the proposed system is more efficient and effective than conventional support vector machines （SVMs） and TWSVMs.

关键词： intrusion detection system (IDS) twin support vector machines (TWSVMs) probability

A THREE-DIMENSIONAL DESINGULARIZED HIGH ORDER PANEL METHOD BASED ON NURBS

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2008年第2期20卷 137-146页

作者： GAO Zhi-liang ZOU Zao-jian State Key Laboratory of Ocean engineering Shanghai Jiaotong University Shanghai 200030 China School of Naval Architecture Ocean and Civil Engineering Shanghai Jiaotong University Shanghai 200030 China

A desingularized high order panel method based on Non-Uniform Rational B-Spline （NURBS） was developed to deal with three-dimensional potential flow problems. A NURBS surface was used to precisely represent the body geometry. Velocity potential on the body surface was described by the B-spline after the source density distribution on the body surface had been solved. The collocation approach was employed to satisfy the Neurnann boundary condition and Gaussian quadrature points were chosen as both the collocation points and the source points. The singularity was removed by a combined method, so the process of the numerical computation was non-singular. In order to verify the method proposed, the unbounded flow problems of sphere and ellipsoid, the wave-making problem of a submerged ellipsoid were chosen as computational examples. It is shown that the numerical results are in good agreement with analytical solutions and other numerical results in all cases, and sufficient accuracy of numerical solution can be reached with a small number of panels.

关键词： potential flow high order panel method Non-Uniform Rational B-Spline (NURBS) desingularization