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Bootstrapping-based Automatic Acquisition of Domain Concepts for Ontology Construction

电子学报(英文版) 2013年第2期22卷 313-318页

作者： YANG Yuehua DU Junping ZI Lingling Beijing Key Laboratory of Intelligent Telecommunication Software and Multimedia School of Computer Science Beijing University of Posts and Telecommunications Beijing 100876 China School of Electronic and Information Engineering L iaoning Technical University Huludao 125105 China

The domain concept is one of the key el- ements of ontology. In order to automatically acquire the domain concepts during the domain ontology construction, we proposed a novel Bootstrapping-based automatic acqui- sition algorithm of domain concepts. In our work, the com- pound words are extracted according to the combination conditions of the mutual information and the information entropy. The candidate domain concepts determinant con- ditions based on the co-occurrence sentences frequency are presented. Besides, to avoid omitting the domain concepts with the lower frequency or semantically similar to other domain concepts, the semantic factor is introduced. The experiments results have demonstrated that the compound domain concepts and the semantically similar domain con- cepts with the lower sentences frequency can also be ex- tracted by using the proposed algorithm. And the pro- posed algorithm has obtained higher precision and recall, so it is effective and feasible.

关键词：领域本体自动获取自举位置算法语义相似引导过程组合条件信息熵

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Facilitating students' collaboration and learning in a question and answer system 13

Facilitating students' collaboration and learning in a quest...

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2013 2nd ACM Conference on Computer Supported Cooperative Work Companion, CSCW 2013

作者： Aritajati, Chulakorn Hari Narayanan, N. Computer Science and Software Engineering Department Intelligent and Interactive Systems Laboratory Auburn University Auburn AL 36849 United States

ISBN: (纸本)9781450313322

Green Dolphin (GD) is a question and answer system for students learning programming, with a social web interface. It crowd-sources the task of answering technical questions to the peers of students who ask questions. GD has several original features that make it different from existing systems. It automatically identifies students who are knowledgeable based on their activity, and tags them as experts to whom other students can ask questions. GD provides students with automatic feedback of the quality of code they submit. Thus, students get fast and high quality answers from their peers and the system, freeing up time for teachers. After a student posts a question in GD, it delays making visible answers from instructors and teaching assistants so that other students are encouraged to participate, and have time to answer the question. We believe that this can significantly increase student participation, collaboration and sense of ownership. Students gain new knowledge from the flow of questions and answers in the system. They develop communication skills by asking and answering questions as well as programming and debugging skills. Copyright © 2012 by the Association for Computing Machinery, Inc. (ACM).

关键词： Students

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Face recognition by nonsubsampled contourlet transform and support vector machine

Face recognition by nonsubsampled contourlet transform and s...

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2nd International Conference on Information engineering and Applications, IEA 2012

作者： Wang, Yuehao College of Software Engineering Key Laboratory of Machine Vision and Intelligent Information System Chongqing University of Arts and Sciences Chongqing 402160 China

ISBN: (纸本)9781447148555

This paper proposed a new face recognition method based on nonsubsampled contourlet transform (NSCT) and component-based support vector machine (SVM). This approach takes technological advantages of both SVM for classification and the NSCT for facial feature extraction. We named the new method combining the nonsampled contourlet transform and SVM as NSCT-SVM. The experimental results on ORL and MIT-CBCL face database demonstrate that our face recognition method is effective and competitive. © 2013 Springer-Verlag.

关键词： Face recognition

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Multifocus Image Fusion Using Local Perceived Sharpness

Multifocus Image Fusion Using Local Perceived Sharpness

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第25届中国控制与决策会议

作者： Liang Xu Junping Du JangMyung Lee Qian Hu Zhenhong Zhang Ming Fang Qian Wang Beijing Key Laboratory of Intelligent Telecommunication Software and Multimedia School of Computer Science Beijing University of Posts and Telecommunications Department of Electronics Engineering Pusan National University

ISBN: (纸本)9781467355339

Image fusion has become a valuable tool in many applications. In this paper, we propose a conceptually clear and intuitive algorithm for region-based image fusion. Our method considers the properties of multifocus images: in focus regions are clear, but out of focus regions are blurring. Source images are first decomposed into perceptually homogeneous regions and then combine them by use of local perceived sharpness （LPS）. Compared to several state-of-the-art image fusion algorithms, experimental results demonstrate that the proposed method is superior in both objective and visual evaluations.

关键词： Image Fusion Local Perceived Sharpness Superpixels

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Percolation theory-based exposure-path prevention for wireless sensor networks coverage in internet of things

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IEEE Sensors Journal 2013年第10期13卷 3625-3636页

作者： Liu, Liang Zhang, Xi Ma, Huadong Beijing Key Laboratory of Intelligent Telecommunications Software and Multimedia Beijing University of Posts and Telecommunications Beijing 100876 China Networking and Information Systems Laboratory Department of Electrical and Computer Engineering Texas AandM University College Station TX 77843 United States

Deriving the critical density to achieve region coverage for random sensor deployment is a fundamentally important problem in the area of Internet of Things (IoT). Most of the existing works on sensor coverage mainly concentrate on the full coverage models, which ensure that all points in the deployment region are covered at the expense of high complexity and cost. In contrast, many applications of IoT focus on the exposure-path prevention, which does not require full coverage sensor deployment, and instead it only needs the partial coverage, because the exposure paths are prevented as long as no moving objects or phenomena can go through a deployment region without being detected. Finally, we focus on the partial coverage by applying the percolation theory to solve the exposure path problem for the network of sensors in IoT. Most of the existing percolation-based schemes apply the continuum-percolation theory, which, however, suffers from the loose lower and upper bounds on the critical density. To overcome this problem, we propose a bond-percolation theory based scheme by mapping the exposure path problem into a bond percolation model. Using this model, we derive the critical densities for both omnidirectional sensor networks and directional sensor networks under random sensor deployment where sensors are deployed according to a two-dimensional Poisson process. The rigorous modeling/analyses and extensive simulations show that our proposed scheme can yield much tighter upper and lower bounds on the critical densities as compared with those generated by continuum-percolation. © 2001-2012 IEEE.

关键词： Wireless sensor networks

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Cooperative Bicircular Target Tracking Using Multiple Unmanned Aerial Vehicles

Cooperative Bicircular Target Tracking Using Multiple Unmann...

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IEEE Annual Conference on Decision and Control

作者： Yueqian Liang Yingmin Jia Junping Du Fumitoshi Matsuno Seventh Research Division and the Department of Systems and Control Beihang University (BUAA) Beijing 100191 China Beijing Key Laboratory of Intelligent Telecommunications Software and Multimedia School of Computer Science and Technology Beijing University of Posts and Telecommunications Beijing 100876 China Department of Mechanical Engineering and Science Kyoto University Kyoto 606-8501 Japan

ISBN: (纸本)9781467360890

This paper investigates the problem of tracking a moving target using multiple fixed-wing unmanned aerial vehicles (UAVs) under a new bicircular formation. This new formation for cooperative standoff target tracking is first developed by maximizing the amount of Fisher information. Guidance vector fields are designed, and based on them, a cooperation approach is proposed to adapt the unknown target velocity and achieve the cooperative bicircular tracking. Speed and heading rate are firstly controlled to track the guidance vector fields separately for each UAV, then the speed is further adjusted to maintain the desired angular separation between the UAVs. Simulation experiments are given to verify the effectiveness of the proposed approach.

关键词： bicircular Target tracking vehicle

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Robust H_∞ Consensus Control of Uncertain Multi-Agent Systems with Nonlinear Dynamics and Time-Varying Delays

Robust H_∞ Consensus Control of Uncertain Multi-Agent Syste...

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American Control Conference

作者： Ping Wang Yingmin Jia Junping Du Jun Zhang Seventh Research Division and the Department of Systems and Control Beihang University (BUAA) Beijing 100191 China Beijing Key Laboratory of Intelligent Telecommunications Software and Multimedia School of Computer Science and Technology Beijing University of Posts and Telecommunications Beijing 100876 China School of Electronic and Information Engineering Beihang University (BUAA) Beijing 100191 China

ISBN: (纸本)9781479932757

This paper is concerned with the H_∞ consensus control problem in undirected networks of autonomous agents with nonlinear dynamics, subject to parameter uncertainties and external disturbances. With the consideration of time-varying delays arising from communication among agents, a distributed protocol is proposed using the local delayed state information. Then, by defining an appropriate controlled output function, the consensus problem under the proposed protocol is converted into an H_∞ control problem. Based on robust H_∞ theory, sufficient conditions are derived to make all agents achieve consensus with desired H_∞ performance. Moreover, the feedback matrix in the proposed protocol is determined by solving two linear matrix inequalities (LMIs) with the same dimensions as a single agent. Finally, a numerical simulation is provided to demonstrate the effectiveness of our theoretical results.

关键词： Multi-agent systems Protocols Nonlinear dynamical systems Uncertain systems Linear matrix inequalities Robustness Delay effects

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Output feedback tracking control for spacecraft relative translation subject to input constraints and partial loss of control effectiveness

Output feedback tracking control for spacecraft relative tra...

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American Control Conference

作者： Lin Zhao Yingmin Jia Junping Du Jun Zhang Seventh Research Division and the Department of Systems and Control Beihang University (BUAA) Beijing 100191 China Beijing Key Laboratory of Intelligent Telecommunications Software and Multimedia School of Computer Science and Technology Beijing University of Posts and Telecommunications Beijing 100876 China School of Electronic and Information Engineering Beihang University (BUAA) Beijing 100191 China

ISBN: (纸本)9781479932757

In this paper, an adaptive output feedback tracking control scheme is proposed for spacecraft formation flying (SFF) in the presence of external disturbances, uncertain system parameters, input constraints and partial loss of control effectiveness. The proposed controller incorporates a pseudo-velocity filter to account for the unmeasured relative velocity, and the neural network (NN) technique is implemented to approximate the desired nonlinear function and bounded external disturbances. In order to guarantee that the output of the NN used in the controller is bounded by the corresponding bound of the approximated nonlinear function, a switch function is employed to generate a switching between the adaptive NN control and the robust controller. Moreover, a fault tolerant part is included in the controller to compensate the partial loss of actuator effectiveness fault. It is shown that the derived controller not only guarantees the tracking error in the closed-loop system to be uniformly ultimately bounded (UUB) but also ensures the control input can rigorously enforce actuator magnitude constraints. Simulation results are provided to demonstrate the effectiveness of the proposed method.

关键词： SFF UUB NN

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Super-resolution for surveillance facial images via shape prior and residue compensation

International Journal of Multimedia and Ubiquitous Engineeri...

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International Journal of Multimedia and Ubiquitous engineering 2013年第6期8卷 47-58页

作者： Lu, Tao Hu, Ruimin Jiang, Junjun Zhang, Yanduo He, Wei Hubei Province Key Laboratory of Intelligent Robot College of Computer Science and Engineering Wuhan Institute of Technology Wuhan 430073 China National Engineering Research Center on Multimedia Software Wuhan University Wuhan 430072 China Transportation Engineering Institute of Minjiang University Fuzhou 350001 China

Super-resolution (SR) methods are widely used to enhance the resolution of input images such as low-resolution (LR) remote or surveillance images. The key problem of SR algorithm is to introduce a proper prior for high-resolution (HR) image reconstruction. Usually pixel feature based similarity measure is used as prior. While in real surveillance applications, images are often disturbed by noise so that it is not enough to only use the prior from pixel domain to achieve satisfied high-resolution. In this paper, a two-phase based face hallucination approach via shape prior (SP) is proposed. Firstly, the Active Appearance Model (AAM) is used as shape prior to reconstruct the global face. Then the high frequency information as detailed inartificial facial features of HR face image is compensated to the global face. Experiments show that the proposed algorithm improves the subjective and objective quality of the input LR facial images and outperform many states-of-the-art superresolution methods. © 2013 SERSC.

关键词： Pixels

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Distributed adaptive two-stage Kalman filter for target tracking in the presence of unknown dynamic bias

Distributed adaptive two-stage Kalman filter for target trac...

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Chinese Control Conference (CCC)

作者： Cui Zhang Yingmin Jia Junping Du Jun Zhang The Seventh Research Division Beihang University (BUAA) Beijing P. R. China Beijing Key Laboratory of Intelligent Telecommunications Software and Multimedia Beijing University of Posts and Telecommunications Beijing P. R. China School of Electronic and Information Engineering Beihang University (BUAA) Beijing P. R. China

This paper is concerned with the problem of tracking target with multiple sensors in the presence of unknown dynamic bias. A suboptimal adaptive two-stage Kalman filter (ATKF) is designed with two reduce-order filters to estimate the target state and the dynamic bias in parallel when the bias model information is incomplete. Moreover, a distributed adaptive two-stage Kalman filter (DATKF) is developed for multi-sensor system based on the ATKF. The effectiveness of the ATKF and the DATKF are illustrated by the Monte Carlo simulation results.

关键词： Kalman filters Mathematical model Adaptation models Equations Sensor fusion Vectors

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