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Automated Map Generalization in Distributed Environments

Automated Map Generalization in Distributed Environments

The Second International Joint Conference on Computational Science and Optimization(CSO 2009)(2009 国际计算科学与优化会议)

作者： Qinghua Qiao Tong Zhang Key Laboratory of Geo-Informatics of State Bureau of Surveying and Mapping Chinese Academy of Survey Intelligent Transportation Systems Center Wuhan University of Technology Wuhan China 430063

Current map generalization for massive spatial data is becoming more and more urgent. It is necessary to study the integration of new technologies, such as distributed computing, which is important to provide high-quality geographic information services. This paper proposes an architecture of automated map generalization in distributed environments, and implements a prototype system to demonstrate the architecture. Finally an experiment to generalize contour data for entire China from scale 1:250,000 to 1:1,000,000 was performed with prototype system.

关键词： Distributed computing Earth Data processing Geographic Information systems Computer networks Computer architecture Prototypes intelligent transportation systems Remote sensing Application software

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Blind separation of superimposed images with unknown motions

Blind separation of superimposed images with unknown motions

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Conference on Computer Vision and Pattern Recognition (CVPR)

作者： Kun Gai Zhenwei Shi Changshui Zhang State Key Laboratory on Intelligent Technology and Systems Tsinghua National Laboratory for Information Science and Technology (TNList) Department of Automation Tsinghua University Beijing China Image Processing Center School of Astronautics Beihang University Beijing China

We consider the blind separation of source layers from superimposed mixtures thereof, involving unknown motions and unknown mixing coefficients of layers in each mixture. Previous blind separation approaches for such problems assume motions to be uniform translations, and hence are limited for real world applications. In this paper, we develop a sparse blind separation algorithm to estimate both parameterized motions and mixing coefficients. Then, a novel reconstruction approach is presented to recover all layers, by utilizing not only the mixing model but also the statistical properties of natural images. The whole method can handle more general motions than translations, including scalings, rotations and other transformations. In addition, the number of layers is automatically identified, and all layers can be recovered even in the under-determined case where mixtures are fewer than layers. The effectiveness of this technology is shown in the experiments on two simulated mixtures of four layers, real photos containing transparency and reflections, and real crossfade images from videos.

关键词： Image reconstruction Motion estimation Optical reflection Cameras Laboratories Space technology Parameter estimation Videos Glass Layout

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Step-size variable gait planning for biped robot based on LIPM

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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 121-124页

作者： Feng, Shuai Sun, Zengqi State Key Laboratory of Intelligent Technology and Systems Tsinghua University Beijing 100084 China

In order to improve the mobility of biped walking, a gait planning method based on linear inverted pendulum model (LIPM) is proposed. First, the position of the center of mass (COM), when the leg-switching begins, is obtained according to the expected step length. Secondly, the time when the COM arrives at the position is calculated based on the dynamics of the LIPM. Finally, the swing foot's trajectory is planned by using sinusoid to make sure that the swing foot can obtain the desired foothold at the right time. Through this method, a biped robot can enhance its walking mobility by changing its step length during walking. Furthermore, the experimental results applied on an actual biped robot show that this method is effective and practical.

关键词： Inverted pendulum

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Two-mode discrete-time jump fuzzy control of uncertain networked control system

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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 288-293页

作者： Wu, Fengge Sun, Fuchun Liu, Huaping Li, Zidi State Key Laboratory of Intelligent Technology and Systems Tsinghua University Beijing 100084 China

The problem of stochastic stability and controller design for a class of uncertain nonlinear networked control systems (NCSs) is studied. Aiming at the NCSs with the stochastic but bounded delay and packets dropout, a discrete-time jump fuzzy method is presented, which implements the double-mode Takagi-Sugeno fuzzy modeling of the NCSs. This model describes the network characteristics of the stochastic but bounded delays, packets dropout, asymmetry, and uncertain nonlinear dynamics of controlled plants. Based on this model, by using the Lyapunov theory and the linear matrix inequality (LMI) approach, sufficient conditions for stochastic stability of the system are derived, and the design method of the state feedback guaranteed cost controller with piecewise quadratic Lyapunov stability and the sub-optimal performance index is also obtained. The design approach can be cast into a set of bilinear matrix inequalities (BMI), which can be solved by the proposed homotopy algorithm. The results of an numerical example and simulations demonstrate that for any allowable uncertainty the proposed controller can make the system stochastically stable.

关键词： Networked control systems

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Controller design of networked control system based on GA

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Zhongnan Daxue Xuebao (Ziran Kexue Ban)/Journal of Central South University (Science and technology) 2009年第SUPPL. 1期40卷 15-18页

作者： Deng, Jian-Qiu Sun, Zeng-Qi State Key Laboratory of Intelligent Technology and Systems Department of Computer Science and Technology Tsinghua University Beijing 100084 China

The controller in NCS are currently conservative and not effectiveness in selecting its parameters. A modified genetic algorithm (GA) was proposed. The algorithm was used to design the optimal controller gain and adjust other parameters of the controller. The experiment results show that the GA is robust and adaptive and the controller can effectively improve the performance of the NCS.

关键词： Networked control systems

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Motion planning with obstacle avoidance for kinematically redundant manipulators based on two recurrent neural networks

Motion planning with obstacle avoidance for kinematically re...

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IEEE International Conference on systems, Man and Cybernetics

作者： Xiaolin Hu Jun Wang Bo Zhang Department of Computer Science and Technology Tsinghua University Beijing China State Key Laboratory of Intelligent Technology and Systems Tsinghua National Laboratory for Information Science and Technology Beijing China Department of Mechanical and Automation Engineering Chinese University of Hong Kong New Territories Hong Kong China

Inverse kinematic motion planning of redundant manipulators by using recurrent neural networks in the presence of obstacles and uncertainties is a real-time nonlinear optimization problem. To tackle this problem, two subproblems should be resolved in real time. One is the determination of critical points on a given manipulator closest to obstacles, and the other is the computation of joint velocities of the manipulator which can direct the manipulator following a desired trajectory and away from obstacles if it is getting close to them. Different from our previous approaches where the critical points on the manipulator were assumed to be known, these points are to be computed by using a recurrent neural network in the paper. A time-varying quadratic programming problem is formulated for avoiding polyhedral obstacles. In view that the problem is not strictly convex, an existing recurrent neural network, general projection neural network, is applied for solving it. By introducing a velocity smoothing technique into our previous quadratic programming formulation of the joint velocity assignment problem, a recently developed recurrent neural network, improved dual neural network, is proposed to solve it, which features lower structural complexity compared with existing neural networks. Moreover, The effectiveness of the proposed neural networks is demonstrated by simulations on the Mitsubishi PA10-7C manipulator.

关键词： Recurrent neural networks Neural networks Quadratic programming Manipulators Laboratories Kinematics Smoothing methods Paper technology Information science technology planning

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A fast mean-field method for large-scale high-dimensional data and its application in colonic polyp detection at CT colonography

A fast mean-field method for large-scale high-dimensional da...

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International Joint Conference on Neural Networks (IJCNN)

作者： Shijun Wang Ronald M. Summers Changshui Zhang Department of Radiology and Imaging Sciences National Institutes of Health DHHS Bethesda MD USA State Key Laboratory of Intelligent Technologies and Systems Department of Automation Tsinghua National Laboratory for Information Science and Technology Tsinghua University Beijing China

In this paper, we propose a fast mean-field method called LHMF to handle probabilistic models of large-scale data in high dimensional space. By using diffusion map locally linear embedding method which is a non-linear dimensionality reduction method, we first embed the high dimensional data into a low dimensional space. Then we construct a coarse-grained graph which preserves the spectral properties of original weighted graph in the high dimensional space by clustering. A new spin model is defined in the diffusion space and the geometric centroids of clusters represent variables in the new spin model. The calculation demand of mean-field methods can be reduced greatly on the coarse-grained spin model. The final marginal moments of original variables are derived from the states of geometric centroids by using geometric harmonics. We first tested the proposed method on the MNIST hand-written digits dataset. Experimental results show that the LHMF method is competent with consistency approach, a state-of-the-art semi-supervised learning method. Then we applied the proposed method to a large-scale colonic polyp dataset from computed tomography (CT) scans. Free-response operator characteristic analysis shows that our method achieves higher sensitivity with lower false positive rate compared with support vector machines.

关键词： Large-scale systems Colonic polyps Virtual colonoscopy Solid modeling Computed tomography Semisupervised learning Physics Microscopy Laboratories Neural networks

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Grid-enabled High Performance GIS Web Portals

Grid-enabled High Performance GIS Web Portals

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The Second International Joint Conference on Computational Science and Optimization(CSO 2009)(2009 国际计算科学与优化会议)

作者： Tong Zhang Qinghua Qiao Qing Wu Intelligent Transportation Systems Research Center Wuhan University of Technology Wuhan430063 Chi Key Laboratory of Geo-lnformatics of State Bureau of Surveying & Mapping Chinese Academy of Surveyi School of Logistics Engineering Wuhan University of Technology Wuhan 430063 China

This paper introduces a design framework for developing GIService web portals which are supported by Grid computing and Service-Oriented Architecture. A GIS web portal can be enhanced by Grid computing technologies to improve its performance, usability and security. The loosely-coupled Internet GIServices can be combined and integrated by implementing Service-Oriented Architecture (SOA). The Grid computing and SOA paradigms introduce new challenges for designing efficient and flexible GIS web portals. Given these challenges, a new framework is proposed. Following the framework, a technical implementation plan is outlined toward building Grid-enabled high performance GIService web portals using the state-of-the-art computing technologies, including Grid computing, Web services, and web portals. A prototype demonstrates the feasibility of the technical plan.

关键词： Geographic Information systems Portals Grid computing Service oriented architecture Usability Security Web and internet services Buildings Computers Web services

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基于非高斯性最大化的鬼波压制

基于非高斯性最大化的鬼波压制

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CPS/SEG北京2009国际地球物理会议

作者： Xuan Mo Wen-kai Lu State Key Laboratory of Intelligent Technology and Systems Tsinghua National Laboratory for Information Science and TechnologyDepartment of AutomationTsinghua University

在海洋地震信号处理中，鬼波是一种常见的不利的效应。本文提出了一种基于非高斯性最大化的参数搜索的方法来估计海面反射系数和鬼波时延这两个参数。通过这两个参数，我们设计鬼波滤波器来对接收到的地震信号进行反卷积，从而得到拥有... 详细信息

在海洋地震信号处理中，鬼波是一种常见的不利的效应。本文提出了一种基于非高斯性最大化的参数搜索的方法来估计海面反射系数和鬼波时延这两个参数。通过这两个参数，我们设计鬼波滤波器来对接收到的地震信号进行反卷积，从而得到拥有更多信息、更高分辨率的地震信号。文中，该方法对人工合成数据和实际数据都有很好的效果。

关键词：鬼波压制非高斯性最大化海洋地震信号处理海面反射系数

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一种改进的利用频移估计Q值的方法

一种改进的利用频移估计Q值的方法

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CPS/SEG北京2009国际地球物理会议

作者： Ning Tu Wen-kai Lu State Key Laboratory of Intelligent Technology and Systems Tsinghua National Laboratory for Information Science and TechnologyDepartment of AutomationTsinghua University

现有的Q 值估计方法中，主要有两种利用振幅谱频移的方法：质心频率频移法和峰值频率频移法。这两种方法各有优缺点。在本篇文章中，我们详细的讨论并比较这两种方法，并在此基础上提出一种新的利用频移进行Q 值估计的方法。这种方法综... 详细信息

现有的Q 值估计方法中，主要有两种利用振幅谱频移的方法：质心频率频移法和峰值频率频移法。这两种方法各有优缺点。在本篇文章中，我们详细的讨论并比较这两种方法，并在此基础上提出一种新的利用频移进行Q 值估计的方法。这种方法综合了现有两种方法的优点。合成数据实验证实了这种方法的有效性。

关键词： Q值估计质心频率峰值频率频移法

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