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13th International Congress on Sound and Vibration 2006, ICSV 2006

作者： Xu, S.J. Wang, M.H. Zhou, Y. Tu, J.Y. School of Aerospace Tsinghua University Beijing 100084 China State Key Laboratory for Turbulence and Complex System Peking University Beijing 100871 China Department of Mechanical Engineering Hong Kong Polytechnic University Hung Horn Kowloon Hong Kong School of Aerospace Mechanical and Manufacturing Engineering RMIT University Australia

ISBN: (纸本)9781627481502

The 2-D incompressible N-S equations in a moving cylindrical coordinate were reduced to a linear boundary vorticity equation on the cylinder surface with the no-slip condition applied. The solution to the reduced vorticity equation unveils that vorticity generated by the cylinder surface comprises of two components: i) unsteady and anti-symmetrical component, dependent of the cylinder oscillation;ii) steady alternating component associated with the natural vortex shedding. The competition of the two components, interactions among cylinder-vortices and vortex-vortex result in the occurrence of the flow modes. In the first-stage work, a semi-empirical prediction of the occurrence of the S-II mode is in agreement with previously reported experimental and numerical data. Further analysis is under way to predict the occurrence of all other flow modes.

关键词： Vortex flow

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A Visual Positioning Method Based on Relative Orientation Detection for Mobile Robots

A Visual Positioning Method Based on Relative Orientation De...

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2006 IEEE/RSJ International Conference on Intelligent Robots and systems

作者： De Xu Youfu Li Min Tan Key Laboratory of Complex System and Intelligence Science Institute of Automation Chinese Academy and Sciences Beijing China The Key Laboratory of Complex System and Intelligence Science Chinese Academy of Sciences Beijing P. R. China Department of Manufacturing Engineering and Engineering Management City University of Hong Kong Kowloon Hong Kong

In this paper, a new visual positioning method based on corresponding points at two adjacent views is developed for mobile robots. A camera is mounted on a wheeled mobile robot with nonholonomic constraints. The camera whose intrinsic parameters are well calibrated can rotate around an axis perpendicular to the ground plane. The relative orientation and scaled position offsets of the mobile robot are computed from the corresponding points in the common part of the views despite their unknown positions in Cartesian space. The relative orientation is used in a simple visual dead reckoning method to modify the odometry information. Then, based on the relative orientation and modified odometry information, equations are given to determine the position and orientation of the mobile robot. Experiments are performed to verify the effectiveness of the proposed methods

关键词： Mobile robots Robot vision systems Cameras Dead reckoning Intelligent robots Manufacturing automation Simultaneous localization and mapping Laboratories Intelligent manufacturing systems Robotics and automation

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A New Kind of Subjective Trust Model

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Wuhan University Journal of Natural Sciences 2006年第6期11卷 1457-1461页

作者： ZHANG Guangwei KANG Jianchu LUO Ziqiang MENG Xiangyi FANG Peici LI Deyi State Key Laboratory of Software Development Environment Beijing University of Aeronautics and Astronautics Beijing 100083 China China Electronic System Engineering Company Beijing 100840 China

Based on the outstanding characteristics of Cloud Model on the process of transforming a qualitative concept to a set of quantitative numerical values, a formalized model of subjective trust is introduced by which we can transform between qualitative reputation and quantitative voting data. The present paper brings forward algorithms to compute direct trust and recommender trust. Further more, an effective similarity measuring method used to distinguish two users＇ reputation on knowledge level is also proposed. The given model properly settles the uncertainty and fuzziness properties of subjective trust which is always the weakness of traditional subjective trust model, and provides a step in the direction of proper understanding and definition of human trust.

关键词： subjective trust reputation opens network cloud model uncertainty fuzziness

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Modeling Based on MOGA and the Dynamic ε -SVM for Fermentation Process

Modeling Based on MOGA and the Dynamic ε -SVM for Fermentat...

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World Congress on Intelligent Control and Automation (WCICA)

作者： Xuejin Gao Pu Wang Chongzheng Sun Yating Zhang Huiqing Zhang Jianqiang Yi College of Electronic Information and Control Engineering Beijing University of Technology Beijing China The Key Laboratory of Complex System and Intelligence Science Chinese Academy and Sciences Beijing China

To found the suitable models to describe the behavior of biochemistry systems, the dynamic epsiv-SVM method was proposed on the basis of SVM. Each training sample uses different error. The existed methods for selecting the parameters of SVM not only consume time, but also are difficult to find the optimal parameters. The optimal parameters were automatically decided by using multi-object genetic algorithm (MOGA). A new modeling method that combined MOGA with the dynamic epsiv-SVM was presented. The model for penicillin titer pre-estimate was developed by it in Matlab 6.5 with data collected from real plant. The model possesses the strong capability of fitting and generalization. Experiments show that the dynamic epsiv-SVM is superior to the standard SVM modeling method. MOGA is very feasible and efficient too

关键词： Mathematical model Support vector machines Artificial neural networks Risk management Educational programs systems engineering education Genetic algorithms Computer languages Sun Educational institutions

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Visual Positioning Using Four-Point Planar Patterns

Visual Positioning Using Four-Point Planar Patterns

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IEEE International Conference on Automation Science and engineering (CASE)

作者： De Xu Youfu Li Min Tan The Key Laboratory of Complex System and Intelligence ScienceInstitute of Automation Chinese Academy and Sciences Beijing China Department of Manufacturing Engineering and Engineering Management City University of Hong Kong Hong Kong China

The existence of multi-resolutions for the perspective-n-point (PnP) problem makes the position-based visual control based on PnP positioning method difficult for practical applications. In this paper, two simple four-point patterns are designed to ensure unique solution for the PnP problem. One is a triangle planar pattern, which consists of three points and their centroid. Another is quadrangle planar pattern. A recursive least square algorithm with a forgetting factor is introduced to improve the solution accuracy. The positioning accuracy based on PnP positioning method is investigated for the two patterns. The method presented in this paper has the advantages of minimum set of known points providing unique solution and linear pose estimation. Experiments are performed to verify the effectiveness of the proposed patterns and method.

关键词： Cameras Manufacturing automation Laboratories Intelligent manufacturing systems Least squares methods Optical imaging Research and development management Automatic control Control systems Recursive estimation

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A Robust Controller of a Flexible Manipulator Using Genetic Algorithm

A Robust Controller of a Flexible Manipulator Using Genetic ...

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International Conference on Control, Automation, Robotics and Vision (ICARCV)

作者： Lingli Cui Jianyu Zhang Lixin Gao Feiyue Wang College of Mechanical Engineering and Applied Electronics Technology Beijing University of Technology Beijing China Key laboratory of Complex System and Intelligent Science Institute of Automation Chinese Academy and Sciences Beijing China

This paper addresses the issues related to the design of robust controller using genetic algorithms (GA) for lightweight, one-link flexible manipulators working under dynamic environments and other uncertain influences. By selecting sensitivity weight functions properly using the GA method, a mixed sensitivity H infin controller is developed to ensure robustness of manipulator control systems for varying payloads and other modeling uncertainties. Numeric simulation has been conducted and the results have demonstrated the effectiveness of the proposed method

关键词： Robust control Genetic algorithms Manipulator dynamics Structural beams Payloads Mathematical model Lighting control Paper technology Uncertainty Robust stability

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Polar LEO satellite constellation measurement by delay probing

Polar LEO satellite constellation measurement by delay probi...

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IEEE International Conference on Performance, Computing and Communications (IPCCC)

作者： Junfeng Wang Hongxia Zhou Fanjiang Xu Mingtian Zhou College of Computer Science and Engineering University of Electronic Science and Technology ChengDu China National Key Laboratory of Integrated Information System Technology Institute of Software Chinese Academy and Sciences Beijing China Chongqing Communication College Chongqing China

Low Earth orbit (LEO) satellite networks are capable of providing wireless connectivity seamlessly and continuously to any part of the world with guaranteed short round-trip propagation delay. As a key part of next generation network (NGN) infrastructure, next generation satellite networks are expected to support a variety of applications with diverse performance requirements. This paper argues that the constellation tomography for the LEO satellite network is a preliminary step for efficient satellite network monitoring and performance promotion. To measure the constellation, a divide-and-conquer mechanism is developed for each parameter estimation by delay probing. The delay measurement is only carried out between two terminals located at the same geographic positions. Performance evaluation on several popular polar LEO constellations proves the accuracy and efficiency of the developed constellation tomography algorithms in divide-and-conquer manner. The geographic position limitation of the delay probing terminals for valid constellation inference is also analyzed in the paper

关键词： Low earth orbit satellites Satellite constellations Extraterrestrial measurements Next generation networking Tomography Propagation delay Monitoring Parameter estimation Delay estimation Position measurement

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Topological dynamics characterization for layered satellite networks

Topological dynamics characterization for layered satellite ...

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IEEE International Conference on Performance, Computing and Communications (IPCCC)

作者： Junfeng Wang Yuemei Hu Hongxia Zhou Mingtian Zhou College of Computer Science and Engineering University of Electronic Science and Technology ChengDu China National Key Laboratory of Integrated Information System Technology Institute of Software Chinese Academy and Sciences Beijing China Chongqing Communication College Chongqing China

The highly topological dynamics characterize the most fundamental property of satellite networks contrary to the terrestrial networks. This manifest feature directs the researches on various aspects of satellite networks, including routing and switching architecture selection, routing protocol and reliable transmission control protocol design and enhancement, etc,. The paper quantifies the dynamical activates of layered satellite network topologies. The number and length of network snapshots of one-layered satellite constellations are formulated concisely. The snapshot distributions of typical multi-layered constellations are also evaluated. With this work, it compensates for the simplified topological assumptions in many satellite network related investigations. The thorough understanding of this basic feature not only provides for an accurate quantification of network behavior, but also guides constellation design for future satellite networks

关键词： Low earth orbit satellites Satellite broadcasting Satellite constellations Routing protocols Network topology Next generation networking Quality of service Laboratories Information systems Communication system software

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Effective method on modeling for fermentation process

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Beijing Gongye Daxue Xuebao / Journal of Beijing University of Technology 2006年第5期32卷 405-409页

作者： Gao, Xue-Jin Wang, Pu Sun, Chong-Zheng Yi, Jian-Qiang Zhang, Ya-Ting Zhang, Hui-Qing College of Electronic Information and Control Engineering Beijing University of Technology Beijing 100022 China Key Laboratory of Complex System and Intelligence Science Chinese Academy of Sciences Beijing 100033 China

On the basis of the standard SVM for regression, the dynamic Ε-SVM method was proposed to establish precise mathematical models to describe the behavior of biochemistry systems, namely each training sample used different error. At the same time, an improved multi-objective Genetic Algorithm (MOGA) was used to automatically select the dynamic Ε-SVM parameters. A new modeling method that combined improved MOGA with dynamic Ε-SVM regression was presented. The model for titer pre-estimate was developed in Matlab6.5 with data collected from real plant. The model possessed the strong capability of fitting and generalization. It is shown that the method achieves significant improvement in the generalization performance in comparison with the modeling method based on MOGA and the standard SVM.

关键词： Fermentation

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Security analysis and improvement of hsu et al.'s threshold proxy signature scheme

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International Journal of Network Security 2006年第1期2卷 69-72页

作者： Guo, Lifeng Cheng, Xiangguo Liu, Yang Institute of Systems Science Academy of Mathematics and System Sciences Chinese Academy of Sciences Graduate School of Chinese Academy of Sciences Beijing 100080 China 21 Heng Mui Keng Terrace Singapore State Key Laboratory of Integrated Services Network Xidian University Xi'an 710071 China Software Institute School of Electronic Engineering and Computer Science Peking University 100871 China

In 1999, Sun et al. proposed a new (t, n) threshold proxy signature scheme based on Zhang's threshold proxy signature scheme. But in 2003 Hsu et al. pointed out that Sun's scheme suffered from a drawback and demonstrated an improvement to counter it. In this paper we point out that Hsu's scheme suffers from an insider attack against their scheme. That is, a malicious proxy signer can forge a valid threshold proxy signature on any message. To thwart this attack, some improvements are further proposed.

关键词： Authentication

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