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Methodology Research on Refraction Stack Imaging of Refractive Seismic Recording

Chinese Journal of Geophysics 2013年第1期44卷 128-134页

作者： Tai-Lin FENG Xue-Gong ZHANG Yan-Da LI Tian-Cheng BAI Yun LI Gui-Xiang YANG Xiu-Lian LU Department of Automation Tsinghua University Beijing 100084 China State Key Laboratory of Intelligent Technology and Systems of China Jiangsu Petroleum Administration Bureau Yangzhou 225261 China

Multi-fold refractive seismic exploration is such a method that is generally used to trace the geological structural interfaces when the reflected seismic section is not good or used to trace the base structural configuration and to study the base interface. This paper will discuss the theory and method of imaging underground refractors with the refractied seismic waves in the refractied seismic data, based on the refraction theory. The method was called common depth refraction segments stack imaging method. The velocity analysis steps and NMO processing of the refractive wave by use of the theory and the method will also be given. A better imaging method, the common depth refractive point stack imaging method, will be proposed in the paper. Finally, the exactness and the practicality of the given methods will be verifired by processing model example and real data.

关键词： Seismic prospecting Refracted waves Refractor velocity analysis Stack

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A Lightweight Decentralized Algorithm for Jointly Sparse Optimization

A Lightweight Decentralized Algorithm for Jointly Sparse Opt...

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第三十二届中国控制会议

作者： Jie Zhu Yongcheng Li Meisheng Xue Qing Ling Department of Automation University of Science and Technology of China State Key Laboratory of Complex Electromagnetic Environmental Effects on Electronics & Information System

ISBN: (纸本)9781479900305

This paper develops a lightweight decentralized algorithm to solve the convex jointly sparse optimization problem, as known as the group *** a networked multi-agent system,each agent takes linear measurements from its signal,and all signals share the same sparsity *** decentralized jointly sparse optimization,agents collaborate to recover their signals by taking advantage of the same sparsity pattern,but they are allowed to have limited information exchange with their one-hop *** propose to use the block coordinate descent algorithm to solve the convex jointly sparse optimization problem in a centralized manner,and adopt an inexact average consensus technique for its decentralized *** proposed decentralized algorithm is lightweight;each agent neither exchanges its measurement matrix and measurement vector nor shares its current estimate of its signal with its one-hop *** results demonstrate the effectiveness of the proposed algorithm,as well as its empirical global convergence to the centralized optimal solution.

关键词： Jointly sparse optimization Networked multi-agent system Decentralized optimization Block coordinate descent

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What is the uniqueness of growth pattern in human flesh search organization?

What is the uniqueness of growth pattern in human flesh sear...

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Pacific Asia Workshop on Intelligence and Security Informatics, PAISI 2013

作者： Wang, Tao Zhang, Qingpeng Fu, Julei Wang, Xiao Zheng, Suncong College of Information System and Management National University of Defense Technology Changsha 410073 China State Key Laboratory of Management and Control for Complex Systems Institute of Automation Chinese Academy of Sciences Beijing 100190 China Department of Systems and Industrial Engineering University of Arizona Tucson AZ United States

ISBN: (纸本)9783642396922

Human Flesh Search is an explosive Web phenomenon these years in China, especially when new media, such as Weibo, appeared. In this research, we present the empirical studies about growing patterns of participated Human Flesh Search user, and unveiled one unique growing property. Based on the empirical findings, we compare it with two others results, one is the common Weibo's growth pattern, and the other is the popularity growth pattern of photo in Flickr. Some differences are proposed and analyzed briefly. © 2013 Springer-Verlag.

关键词： Social networking (online)

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Uncalibrated Path Planning in the Image Space for the Fixed Camera Configuration

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Acta Automatica Sinica 2013年第6期39卷 759-769页

作者： Xin-Wu LIANG Xin-Han HUANG Min WANG Department of Automation Shanghai Jiao Tong University Key Laboratory of System Control and Information Processing of Ministry of Education of China Shanghai 200240 China Department of Control Science and Engineering Huazhong University of Science and Technology Key Laboratory of Image Processing and Intelligent Control of Ministry of Education of China Wuhan 430074 China

Image-based visual servoing can be used to efficiently control the motion of robot manipulators. When the initial and the desired configurations are distant, however, as pointed out by many researchers, such a control approach can suffer from the convergence and stability problems due to its local properties. By specifying adequate image feature trajectories to be followed in the image, we can take advantage of the local convergence and stability of image-based visual servoing to avoid these problems. Hence, path planning in the image space has been an active research topic in robotics in recent years. However, almost all of the related results are established for the case of camera-in-hand configuration. In this paper, we propose an uncalibrated visual path planning algorithm for the case of fixed-camera configuration. This algorithm computes the trajectories of image features directly in the projective space such that they are compatible with rigid body motion. By decomposing the projective representations of the rotation and the translation into their respective canonical forms, we can easily interpolate their paths in the projective space. Then, the trajectories of image features in the image plane can be generated via projective paths. In this way, the knowledge of feature point structures and camera intrinsic parameters are not required. To validate the feasibility and performance of the proposed algorithm, simulation results based on the puma560 robot manipulator are given in this paper.

关键词： Visual servoing path planning uncalibrated camera projective space fixed-camera configuration

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A General Iterative Shrinkage and Thresholding algorithm for non-convex regularized optimization problems

A General Iterative Shrinkage and Thresholding algorithm for...

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30th International Conference on Machine Learning, ICML 2013

作者： Gong, Pinghua Zhang, Changshui Lu, Zhaosong Huang, Jianhua Z. Ye, Jieping State Key Laboratory on Intelligent Technology and Systems Department of Automation Tsinghua University Beijing 100084 China Department of Mathematics Simon Fraser University Burnaby BC V5A 1S6 Canada Department of Statistics Texas A and M University TX 77843 United States Computer Science and Engineering Arizona State University Tempe AZ 85287 United States

ISBN: (纸本)9781629933061

Non-convex sparsity-inducing penalties have recently received considerable attentions in sparse learning. Recent theoretical investigations have demonstrated their superiority over the convex counterparts in several sparse learning settings. However, solving the non-convex optimization problems associated with non-convex penalties remains a big challenge. A commonly used approach is the Multi-Stage (MS) convex relaxation (or DC programming), which relaxes the original non-convex problem to a sequence of convex problems. This approach is usually not very practical for large-scale problems because its computational cost is a multiple of solving a single convex problem. In this paper, we propose a General Iterative Shrinkage and Thresholding (GIST) algorithm to solve the nonconvex optimization problem for a large class of non-convex penalties. The GIST algorithm iteratively solves a proximal operator problem, which in turn has a closed-form solution for many commonly used penalties. At each outer iteration of the algorithm, we use a line search initialized by the Barzilai-Borwein (BB) rule that allows finding an appropriate step size quickly. The paper also presents a detailed convergence analysis of the GIST algorithm. The efficiency of the proposed algorithm is demonstrated by extensive experiments on large-scale data sets. Copyright 2013 by the author(s).

关键词： Iterative methods

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Swarm Stability of Heterogeneous Multi-agent systems via Periodically Intermittent Control

Swarm Stability of Heterogeneous Multi-agent Systems via Per...

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第三十二届中国控制会议

作者： Haili Liang Housheng Su Xiaofan Wang Michael Z. Q. Chen Department of Automation Shanghai Jiao Tong University and Key Laboratory of System Control and Information Processing Ministry of Education of China School of Automation Image Processing and Intelligent Control Key Laboratory of Education Ministry of China Huazhong University of Science and Technology Department of Mechanical Engineering The University of Hong Kong

ISBN: (纸本)9789881563835

This paper investigates distributed leader-following swarm stability of heterogeneous multi-agent systems with periodically intermittent control. We assume that the agents in the network are nonidentical and the coupling matrix is balanced. Each heterogeneous follower is assumed to obtain some information from the leader and the neighbors only on a series of periodically time intervals. We show that the system will be exponentially stable. The stability properties are proved via theoretical analysis and verified via numerical simulations. The stability of the heterogeneous multi-agent systems is proved based on matrix theory and the Lyapunov stability theorem. A numerical example is shown to demonstrate the effectiveness of the theoretical result.

关键词： Multi-agent systems, Heterogeneous systems, Intermittent control, Swarm

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Distributed Leader-following Swarm of Heterogeneous Multi-agent systems *

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IFAC Proceedings Volumes 2013年第13期46卷 13-18页

作者： Haili Liang Housheng Su Xiaofan Wang Michael Z.Q. Chen Department of Automation Shanghai Jiao Tong University and Key Laboratory of System Control and Information Processing Ministry of Education of China Shanghai 200240 China School of Automation Image Processing and Intelligent Control Key Laboratory of Education Ministry of China Huazhong University of Science and Technology Luoyu Road 1037 Wuhan 430074 China Department of Mechanical Engineering The University of Hong Kong Hong Kong

This paper investigates distributed leader-following swarm of heterogeneous multi-agent systems. Comparing with the existing works on leader-following swarm of homogeneous multi-agent systems, this paper is much more approaching the practical situation because the agents have different dynamics. We show that the heterogeneous followers will gather with a certain error lever under some assumptions and conditions. The stability properties have been proven by theoretical analysis and verified via numerical simulation. The stability of the heterogeneous multi-agent systems has been achieved based on matrix theory and the Lyapunov stability theorem. Numerical simulation is given to demonstrate the effectiveness of the theoretical result.

关键词： Swarm Multi-agent systems Heterogeneous systems Distributed control

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Molecular Dynamics Simulation of Residual Stress Generated in EDM

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Procedia CIRP 2013年 6卷 432-437页

作者： X. Yang X. Han F. Zhou M. Kunieda State Key laboratory of Mechanical System and Vibration Shanghai 200240 China Department of Mechanical Engineering and Automation Harbin Institute of Technology Harbin 150001 China Department of Precision Engineering The University of Tokyo Tokyo 113-8656 Japan

Residual stress is one of the main characteristics of the surface machined by electrical discharge machining (EDM). In this paper, the formation mechanism of the surface residual stress, and its distribution were simulated using molecular dynamics methods. It was found that a larger pressure gradient was formed in the melting area during discharge. It was also found that there existed larger stress gradient in the melting region and in the solid region in contact with the melting area. The pressure gradient and the shear stress field is the important reason for the formation of the bulge of the discharge crater. From the distribution of the residual stress, it was found that the residual stress on the electrode surface is tensile while it is compressive inside the electrode, indicating that cracks are easy to be generated in the re-solidified layer.

关键词： Electrical discharge machining (EDM) Residual stress Molecular dynamics (MD)

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Mining effective multi-segment sliding window for pathogen incidence rate prediction

Mining effective multi-segment sliding window for pathogen i...

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作者： Duan, Lei Tang, Changjie Li, Xiaosong Dong, Guozhu Wang, Xianming Zuo, Jie Jiang, Min Li, Zhongqi Zhang, Yongqing School of Computer Science Sichuan University Chengdu 610065 China West China School of Public Health Sichuan University Chengdu 610041 China Department of Computer Science and Engineering Wright State University Dayton 45435 United States National Key Laboratory of Air Traffic Control Automation System Technology Chengdu 610065 China

Pathogen incidence rate prediction, which can be considered as time series modeling, is an important task for infectious disease incidence rate prediction and for public health. This paper investigates the application of a genetic computation technique, namely GEP, for pathogen incidence rate prediction. To overcome the shortcomings of traditional sliding windows in GEP-based time series modeling, the paper introduces the problem of mining effective sliding window, for discovering optimal sliding windows for building accurate prediction models. To utilize the periodical characteristic of pathogen incidence rates, a multi-segment sliding window consisting of several segments from different periodical intervals is proposed and used. Since the number of such candidate windows is still very large, a heuristic method is designed for enumerating the candidate effective multi-segment sliding windows. Moreover, methods to find the optimal sliding window and then produce a mathematical model based on that window are proposed. A performance study on real-world datasets shows that the techniques are effective and efficient for pathogen incidence rate prediction. © 2013 Elsevier B.V. All rights reserved.

关键词： Data mining

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A robotic holder of transcranial doppler probe for CBFV auto-searching

A robotic holder of transcranial doppler probe for CBFV auto...

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International Conference on Information and automation (ICIA)

作者： Quanli Qiu Xiaoping Yang Jia Liu Pandeng Zhang Xinyu Wu Guangdong Provincial Key Laboratory of Robotics and Intelligent System Chinese Academy of Sciences Shenzhen Guangdong China Key Lab of Advanced Manufacturing Technology Harbin Institute of Technology China Department of Mechanical and Automation Engineering The Chinese University of Hong Kong Hong Kong SAR China

ISBN: (纸本)9781479913329

The operational difficulty of Transcranial Doppler (TCD) limits its use in normal clinical settings. We therefore present a robotic arm consists of five degrees of freedom which are achieved by four motors and one extra flexible spring, to assure appropriate pressure on temporal window. With proper control strategies, the robotic arm can move the TCD probe to automatically search temporal window positions. In this paper, we have developed the first full-automatic ambulatory TCD system, evaluated its reliability and efficiency after many experiments. In view of the validation of the instrument in successful experiments, this probe holder is likely to have great impact on future TCD examination.

关键词： Probes DC motors Robots Equations Mathematical model Force Arteries

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