检索结果-内蒙古大学图书馆

Mixed model based SLAM approach for mobile robot

Nanjing Li Gong Daxue Xuebao/Journal of Nanjing University of Science and Technology 2009年第SUPPL. 1期33卷 98-103页

作者： Fang, Fang Ma, Xu-Dong Dai, Xian-Zhong School of Automation Southeast University Nanjing 210096 China Key Laboratory of Measurement and Control of CSE Complex Systems of Engineering Nanjing 210096 China

A new simultaneous localization and mapping approach based on mixed map model using laser data and odometry information is presented in this paper. Mixed model composed of occupancy grids and line maps is utilized to represent environment maps. At the same time Hough transform is introduced to extract line features. Then robot localization and map building task is accomplished using line features matching and extended Kalman filter. Experimental results indicate the feasibility and validity of this approach.

关键词： Extended Kalman filters

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Three-dimensional localization of in vivo bioluminescent source based on multispectral imaging

Three-dimensional localization of in vivo bioluminescent sou...

引用

Medical Imaging 2009: Biomedical Applications in Molecular, Structural, and Functional Imaging

作者： Feng, Jinchao Jia, Kebin Tian, Jie Yan, Guorui Zhu, Shouping The College of Electronic Information and Control Engineering Beijing University of Technology Beijing 100022 China Medical Image Processing Group Key Laboratory of Complex Systems and Intelligence Science Institute of Automation Chinese Academy of Sciences P.O. Box 2728 Beijing 100190 China Life Science Research Center Xidian University Xi'an 710071 China

ISBN: (纸本)9780819475138

Bioluminescence tomography (BLT) is a novel in vivo technique in small animal studies, which can reveal the molecular and cellular information at the whole-body small animal level. At present, there is an increasing interest in multispectral bioluminescence tomography, since multispectral data acquisition could improve the BLT performance significantly. In view to the ill-posedness of BLT problem, we develop an optimal permissible source region strategy to constrain the possible solution of the source by utilizing spectrum character of bioluminescent source. Then a linear system to link the measured data with the unknown light source variables is established by utilizing the optimal permissible region strategy based on adaptive finite element analysis. Furthermore, singular value decomposition analysis is used for data dimensionality reduction and improving computational efficiency in multispectral case. The reconstructed speed and stability benefit from adaptive finite element, the permissible region strategy and singular value decomposition. In the numerical simulation, the heterogeneous phantom experiment has been used to evaluate the performance of the proposed algorithm with the Monte Carlo based synthetic data. The reconstruction results demonstrate the merits and potential of our methodology for localizing bioluminescent source. © 2009 SPIE.

关键词： Singular value decomposition

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Optimal design of oversampled filter banks with lattice structure

Optimal design of oversampled filter banks with lattice stru...

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Asian control Conference

作者： Li Chai Jingxin Zhang Yuxia Sheng Measurement Technology and the Key Laboratory of Metallurgical Equipment and Control Wuhan University of Science and Technology Wuhan China Department of Electrical and Computer Systems Engineering Monash University Clayton VIC Australia

ISBN: (纸本)9781424454402

For an oversampled linear phase (LP) perfect reconstruction filter banks with lattice structure, the synthesis FB is not unique. However, existing methods to choose a synthesis FB for ldquooptimalrdquo noise reduction may destroy the linear phase and lattice structure property. This paper studies the noise reduction design problem for oversampled filter banks (FBs) preserving lattice structure. Both the optimal design and worst case design are considered, where the former caters for the noise with known power spectral density (PSD), and the latter for the noise with unknown PSD. Explicit formula for the former and LMI-based algorithms for the latter are provided.

关键词： Filter bank Lattices Noise reduction Image reconstruction Signal synthesis Image processing Nonlinear filters Optimal control Quantization Noise robustness

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Study of Direction Probability and Algorithm of Improved Marriage in Honey Bees Optimization for Weapon Network System

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Defence Technology（防务技术） 2009年第2期5卷 152-157页

作者：杨晨光涂序彦陈杰 Systems Engineering Research Institute China State Shipbuilding Corporation Department of Automation School of Information Science and Technology Beijing Institute of Technology Ministry of Education of Key Laboratory of Complex System Intelligent Control and Decision Beijing Institute of Technology

To solve the weapon network system optimization problem against small raid objects with low attitude,the concept of direction probability and a new evaluation index system are *** calculating the whole damaging probability that changes with the defending angle,the efficiency of the whole weapon network system can be subtly *** such method,we can avoid the inconformity of the description obtained from the traditional index *** new indexes are also proposed,*** index,overlap index and cover index,which help manage the relationship among several *** normalizing the computation results with the Sigmoid function,the matching problem between the optimization algorithm and indexes is well ***,the algorithm of improved marriage in honey bees optimization that proposed in our previous work is applied to optimize the embattlement *** is carried out to show the efficiency of the proposed indexes and the optimization algorithm.

关键词：网络系统优化问题破坏概率算法改进核武器蜜蜂婚姻 Sigmoid函数

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Meshless local Petrov-Galerkin method for bioluminescent photon propagation in the biological tissue

Meshless local Petrov-Galerkin method for bioluminescent pho...

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Medical Imaging 2009: Biomedical Applications in Molecular, Structural, and Functional Imaging

作者： Qin, Chenghu Tian, Jie Yang, Xin Liu, Kai Feng, Jinchao Xua, Min Medical Image Processing Group Key Laboratory of Complex Systems and Intelligence Science Institute of Automation Chinese Academy of Sciences P. O. Box 2728 Beijing 100190 China Life Science Center Xidian University Xi'an Shaanxi 710071 China The College of Electronic Information and Control Engineering Beijing University of Technology Beijing 100124 China

ISBN: (纸本)9780819475138

As a promising optical molecular imaging modality, bioluminescence tomography (BLT) has attracted remarkable attention for its excellent performance and high cost-effectiveness, which can be employed to speciffically and directly reveal physiological and pathological activities in vivo at molecular and cellular levels. The goal of BLT is to reconstruct the internal bioluminescent light source with surface measurements. Therefore, the calculation of surface light exitance plays an important role in the inverse source reconstruction, whereas photon propagation is complicated because of strongly scattering property of the biological tissue. In this contribution, a novel meshless local Petrov-Galerkin (MLPG) method based on diffusion approximation model is developed to avoid the complex and time-consuming mesh division in the conventional finite element method (FEM), and MLPG requires only a series of discretized nodes without consideration of element information and node connectivity. Compared with other meshless methods based on global weak-form, background cells used for Gauss quadrature are also omitted in the proposed method. In addition, the tissue optical parameters are incorporated as a priori knowledge in this algorithm. Finally, the performance of this method is valuated using two- and three-dimensional numerical simulation experiments. The results demonstrate the effectiveness and feasibility of the presented algorithm to predict boundary bioluminescent light power distribution. © 2009 SPIE.

关键词： Finite element method

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Nonsingular terminal sliding mode guidance law

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Dongnan Daxue Xuebao (Ziran Kexue Ban)/Journal of Southeast University (Natural Science Edition) 2009年第SUPPL. 1期39卷 87-90页

作者： Wang, Zhao Li, Shihua Fei, Shumin School of Automation Southeast University Nanjing 210096 China Key Laboratory of Measurement and Control of Complex Systems of Engineering Southeast University Nanjing 210096 China Dongying 257061 China

In order to intercept maneuvering targets, a guidance law based on nonsingular terminal sliding mode (NTSM) technique is presented. The proposed NTSM contains the line-of-sight (LOS) angular rate and a desired LOS angular. Through introducing the nonlinear sliding mode surface to improve the convergent characteristics of the system, the states of the closed-loop system can be converged to the origin in finite time and the system performance is improved greatly. The LOS angular rate is nullified in finite time to guarantee the zero miss-distance between the missile and the target;the LOS angular reaches the desired value in finite time to guarantee the missile attitude of hitting the target. With the maneuverability of acceleration of the target regarded as an unknown bounded disturbance, the proposed guidance law is robust to target maneuvering by using the invariance of the variable structure control. The guidance law has a simple structure and is easy to be implemented. Two cases of target maneuvering are simulated to validate the effectiveness of the method. The simulation results show that the algorithm has strong robustness and high guidance accuracy.

关键词： Variable structure control

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Social tolerance allows cooperation to prevail in an adaptive environment

引用

Physical Review E 2009年第5期80卷 051104-051104页

作者： Xiaojie Chen Feng Fu Long Wang Center for Systems and Control State Key Laboratory for Turbulence and Complex Systems College of Engineering Peking University Beijing 100871 China Department of Zoology University of British Columbia Vancouver British Columbia Canada V6T 1Z4 Program for Evolutionary Dynamics Harvard University Cambridge Massachusetts 02138 USA

In real situations, individuals often have moderate tolerance toward ambient cooperative environment in which they tend to avoid unfavorable interactions and search for favorable ones. How such social tolerance affects the evolution of cooperation and the resulting cooperative networks remains to be answered. To address this issue, here we present an effective model of co-evolutionary prisoner’s dilemma by introducing cooperative environment and social tolerance for networked players. An individual’s level of cooperative environment characterizes the cooperativity and sustainability of its interaction environment centered on itself. In our model, for paired individuals we assume that the one in better cooperative environment has a certain tolerance threshold to the opponent. If the opponent’s cooperative environment level is beyond the tolerance threshold, the one in better cooperative environment cuts unilaterally the link, and rewires to others. Otherwise, the link is not severed, and meanwhile an inhomogeneous strategy imitation process between them is considered. Moreover, a player’s cooperative environment is adjusted in response to the strategy choices in the neighborhood. Interestingly, we find that there exists a moderate tolerance threshold warranting the best promotion of cooperation. We explain the nontrivial results by investigating the time ratio of strategy (network) updating during the whole process and properties in emerging networks. Furthermore, we investigate the effect of memory-dependent discounting of individuals’ cooperative environment on the evolution of cooperation. We also demonstrate the robustness of our results by considering two other modified co-evolutionary rules. Our results highlight the importance of appropriate tolerance threshold for the evolution of cooperation during the entangled co-evolution of strategy and structure.

关键词： Sustainable development

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Evolutionary dynamics on graphs: Efficient method for weak selection

引用

Physical Review E 2009年第4期79卷 046707-046707页

作者： Feng Fu Long Wang Martin A. Nowak Christoph Hauert Program for Evolutionary Dynamics Harvard University Cambridge Massachusetts 02138 USA Center for Systems and Control State Key Laboratory for Turbulence and Complex Systems College of Engineering Peking University Beijing 100871 China Department of Organismic and Evolutionary Biology and Department of Mathematics Harvard University Cambridge Massachusetts 02138 USA Department of Mathematics University of British Columbia Vancouver British Columbia Canada V6T 1Z2

Investigating the evolutionary dynamics of game theoretical interactions in populations where individuals are arranged on a graph can be challenging in terms of computation time. Here, we propose an efficient method to study any type of game on arbitrary graph structures for weak selection. In this limit, evolutionary game dynamics represents a first-order correction to neutral evolution. Spatial correlations can be empirically determined under neutral evolution and provide the basis for formulating the game dynamics as a discrete Markov process by incorporating a detailed description of the microscopic dynamics based on the neutral correlations. This framework is then applied to one of the most intriguing questions in evolutionary biology: the evolution of cooperation. We demonstrate that the degree heterogeneity of a graph impedes cooperation and that the success of tit for tat depends not only on the number of rounds but also on the degree of the graph. Moreover, considering the mutation-selection equilibrium shows that the symmetry of the stationary distribution of states under weak selection is skewed in favor of defectors for larger selection strengths. In particular, degree heterogeneity—a prominent feature of scale-free networks—generally results in a more pronounced increase in the critical benefit-to-cost ratio required for evolution to favor cooperation as compared to regular graphs. This conclusion is corroborated by an analysis of the effects of population structures on the fixation probabilities of strategies in general 2×2 games for different types of graphs. Computer simulations confirm the predictive power of our method and illustrate the improved accuracy as compared to previous studies.

关键词： Dynamics

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Robust controller Design for Networked control systems with Nonlinear Uncertainties

Robust Controller Design for Networked Control Systems with ...

引用

2009 American control Conference (ACC 2009)

作者： Junyan Yu Long Wang Mei Yu Jie Chen Yingmin Jia Intelligent Control Laboratory Center for Systems and Control College of Engineering and Key Laboratory of Machine Perception (Ministry of Education) Peking University Beijing 100871 P.R.China Department of Automation North China Electric Power University Zhuxinzhuang Dewai Beijing 102206 P.R.China Beijing Institute of Technology Key Laboratory of Complex System Intelligent Control and Decision Ministry of Education Beijing 100081 P.R.China Seventh Research Division Beihang University Beijing 100083 P.R. China

ISBN: (纸本)9781424445233

We address robust stabilization problem for networked control systems with nonlinear uncertainties and packet losses by modelling such systems as a class of uncertain switched systems. Based on theories on switched Lyapunov functions, we derive the robustly stabilizing conditions for state feedback stabilization and design packet-loss dependent controllers by solving some matrix inequalities. A numerical example and some simulations are worked out to demonstrate the effectiveness of the proposed design method.

关键词： Networked control systems robust controller design Packet loss control systems design approach Switched systems controller design State feedback Uncertainty nonlinearity

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Robust adaptive control for uncertain systems with discrete and distributed delays

引用

控制理论与应用（英文版） 2008年第3期6卷 287-292页

作者： Qing ZHU Shumin FEI Tao LI Tianping ZHANG Key Laboratory of Measurement and Control of Complex Systems of Engineering School of Automation Southeast University Nanjing Jiangsu 210096 China College of Information Engineering Yangzhou University Yangzhou Jiangsu 225009 China

In this paper, a robust adaptive control scheme is proposed for the stabilization of uncertain linear systems with discrete and distributed delays and bounded perturbations. The uncertainty is assumed to be an unknown continuous function with norm-bounded restriction. The perturbation is sector-bounded. Combining with the liner matrix inequality method, neural networks and adaptive control, the control scheme ensures the exponential stability of the closed-loop system for any admissible uncertainty.

关键词： Time-delay systems Robust control Adaptive control Neural networks Global exponential stability Linear matrix inequalities

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