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Adaptive output feedback control for uncertain nonholonomic chained systems

Journal of Central South University 2010年第3期17卷 572-579页

作者：袁占平王祝萍陈启军 Department of Electronics and Information Engineering Tongji University Key Laboratory of Embedded System and Service Computing Ministry of Education Tongji University

An adaptive output feedback control was proposed to deal with a class of nonholonomic systems in chained form with strong nonlinear disturbances and drift terms. The objective was to design adaptive nonlinear output feedback laws such that the closed-loop systems were globally asymptotically stable, while the estimated parameters remained bounded. The proposed systematic strategy combined input-state-scaling with backstepping technique. The adaptive output feedback controller was designed for a general case of uncertain chained system. Furthermore, one special case was considered. Simulation results demonstrate the effectiveness of the proposed controllers.

关键词： adaptive output feedback input-state scaling backstepping nonholonomic system

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SelectCast: Scalable data aggregation scheme in wireless sensor networks

SelectCast: Scalable data aggregation scheme in wireless sen...

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IEEE Annual Joint Conference: INFOCOM, IEEE Computer and Communications Societies

作者： Cheng Wang Shaojie Tang Xiang-Yang Li Changjun Jiang Key Laboratory of Embedded System and Service Computing Ministry of Education Shanghai China Department of Computer Science University of Tongji Shanghai China Department of Computer Science Illinois Institute of Technology Chicago IL USA TNLIST School of Software Tsinghua University China

In this work, for a wireless sensor network (WSN) of n randomly placed sensors with node density λ ∈ [1, n], we study the tradeoffs between the aggregation throughput and gathering efficiency. The gathering efficiency refers to the ratio of the number of the sensors whose data have been gathered to the total number of sensors. Specifically, we design two efficient aggregation schemes, called single-hop-length (SLH) scheme and multiple-hop-length (MLH) scheme. By novelly integrating these two schemes, we theoretically prove that our protocol achieves the optimal tradeoffs, and derive the optimal aggregation throughput depending on a given threshold value (lower bound) on gathering efficiency. Particularly, we show that under the MLH scheme, for a practically important set of symmetric functions called perfectly compressible functions, including the mean, max, or various kinds of indicator functions, etc., the data from Θ(n) sensors can be aggregated to the sink at the throughput of a constant order Θ(1), implying that our MLH scheme is indeed scalable.

关键词： TV Wireless sensor networks Power capacitors Blogs Lattices

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Construction-and-extraction based index for images retrieval

IEEJ Transactions on Electronics, Information and Systems

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IEEJ Transactions on Electronics, Information and systems 2011年第7期131卷 1377-1383页

作者： Zhang, Junqi Ni, Lina Tian, Chunqi Gao, Shangce Tang, Zheng Department of Computer Science and Technology Key Laboratory of Embedded System and Service Computing Tongji University Shanghai 200092 China College of Info Sci and Engi Shandong University of Science and Technology Qingdao 266510 China Department of Intellectual Information Systems Engineering University of Toyama Toyama-shi 930-8555 Japan

The past recent years have witnessed more and more applications on image retrieval. As searching a large image database is often costly, to improve the efficiency, high dimensional indexes may help. This paper proposes an adaptive hybrid index (AHI) supported by a construction-and-extraction technique to support image retrieval. First, the image clusters are further partitioned into sub-clusters to reduce the overlap between clusters and indexed into an iDistance index. Then, the query sampling statistically extracts some sub-cluster from the iDistance index into a sequential file. Finally, the users' queries are accurately returned by searching both the iDistance index and the sequential file. It's proved that the proposed AHI never performs worse than the sequential scan. Particularly, the experimental results demonstrate that the proposed index AHI is beneficial and achieves better performance than some exiting methods. It is about 2 times faster than iDistance, almost three times than Omni-sequential, more than four times faster than sequential file and more than 10 times faster than M-tree on the benchmark images set. The effect of the proposed AHI is also investigated by our implemented content based images retrieval system. © 2011 The Institute of Electrical Engineers of Japan.

关键词： Extraction

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Neurological rehabilitation of stroke patients via motor imaginary-based brain-computer interface technology

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Neural Regeneration Research 2011年第28期6卷 2198-2202页

作者： Hongyu Sun Yang Xiang Mingdao Yang Department of Computer Science and Technology Tongji University Shanghai 201804 China College of Information and Electrical Engineering Shandong University of Science and Technology China Key Laboratory of Embedded System and Service Computing Ministry of Education of the People＇s Republic of China Tongji University Shanghai 201804 China Qingdao Economic ＆ Technical Development Area First People＇s Hospital Qingdao 266555 Shangdong Province China

The present study utilized motor imaginary-based brain-computer interface technology combined with rehabilitation training in 20 stroke patients. Results from the Berg Balance Scale and the Holden Walking Classification were significantly greater at 4 weeks after treatment （P 〈 0.01）, which suggested that motor imaginary-based brain-computer interface technology improved balance and walking in stroke patients.

关键词： brain-computer interface motor cortex neuronal plasticity rehabilitation stroke neural regeneration

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Verification of web service protocols by logic of knowledge

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Journal of Information and Computational Science 2011年第6期8卷 921-932页

作者： Chen, Qingliang Su, Kaile Cao, Ying Liu, Chanjuan School of Electronics Engineering and Computer Science Peking University Beijing 100871 China Department of Computer Science Jinan University Guangzhou 510632 China Key Laboratory of Embedded System and Service Computing Ministry of Education Tongji University Shanghai 200000 China Institute for Integrated and Intelligent Systems Griffith University Brisbane Australia

Web services is a popular distributed systems technology and its effectiveness and efficiency rely badly on the underlying protocols. And web service protocols are designed in XML formats so the message structures within are quite different from the conventional ones. Therefore, the well-established formal verification techniques for conventional protocols, which have gained substantial achievements in practice, cannot be applied directly to them because of the inherently different syntax. In this paper, we propose a justification-oriented and automatic formal approach to verify, in the standard Dolev-Yao model, concerned security properties expressed as epistemic notions, i. e., logic of knowledge, for web service protocols, based on a fault-preserving mapping tool called SuD (SOAP under Dolev-Yao). Our approach is significant because, instead of finding flaws in finite number of protocol sessions, the specifications we are to verify can hold in arbitrary number of sessions. © 2011 Binary Information Press.

关键词： Web services

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Modeling and analysis of dual-arm cluster tools for wafer fabrication with revisiting

Modeling and analysis of dual-arm cluster tools for wafer fa...

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IEEE International Conference on Automation Science and Engineering (CASE)

作者： Yan Qiao NaiQi Wu MengChu Zhou Department of Industrial Engineering School of Mechatronics Engineering Guangdong University of Technology Guangzhou China Key Laboratory of Embedded System and Service Computing Ministry of Education Tongji University Shanghai China Department of Electrical and Computer Engineering New Jersey Institute of Technology Newark NJ USA

Some wafer fabrication processes are repeated processes, e.g. atomic layer deposition (ALD) process. For such processes, the wafers need to visit some processing modules for a number of times, which complicates the cycle time analysis. This paper studies the cycle time analysis problem for such processes. With a Petri net model, it is found that such processes contain local cycles involving only the revisiting PMs and global cycles involving both revisiting and non-revisiting PMs. The process switches between these two types of cycles such that the process never reaches a steady state. Based on this finding, the mechanism underlying such processes is revealed and analytical expressions are given for the calculation of their cycle time. Illustrative examples are presented to show the application of the proposed approach.

关键词： Robots Semiconductor device modeling Fabrication Schedules Analytical models system recovery Load modeling

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Polynomial-time hierarchy of computable reals

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Journal of Computational Information systems 2011年第4期7卷 1108-1115页

作者： Chen, Qingliang Su, Kaile Wu, Lijun Department of Computer Science Jinan University Guangzhou 510632 China Key Laboratory of Embedded System and Service Computing Ministry of Education Tongji University Shanghai China Key Laboratory of High Confidence Software Technologies Ministry of Education Peking University Beijing China Institute for Integrated and Intelligent Systems Griffith University Brisbane Australia School of Computer Science and Engineering University of Electronic Science and Technology Chengdu 610054 China

In mathematics, various representations of real numbers have been investigated and all these representations are proved to be mathematically equivalent. Furthermore, it is known that all effective versions of these representations lead to the same class of "computable real numbers". However, when subrecursive (such as primitive recursive) is taken into account, these representations can lead to different notions of "computable real numbers". This paper will look into the polynomial-time version of the problem for computable real numbers under different representations. We will summarize the known results to exhibit the comprehensive hierarchy they form. Our goal is to clarify systematically how the polynomial-time computability depends on the representations of the real numbers. Copyright © 2011 Binary Information Press.

关键词： Polynomial approximation

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An improved foreground object detection method based on Gaussian mixture models

An improved foreground object detection method based on Gaus...

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International Conference on Multimedia Communications

作者： Zhang, Xiayi Liu, Fuqiang Li, Zhipeng Key Laboratory of Embedded System and Service Computing Tongji University Shanghai China

ISBN: (纸本)9780769541365

Statistical background subtraction has proved to be a robust and effective approach for segmenting and extracting objects without any prior information of the foreground objects. This paper presents two contributions on this topic. The first contribution of this paper proposes a novel approach which introduces the motion mask into the Gaussian Mixture Models to reduce the errors of classical GMMs, which always classifies the moving objects as background incorrectly, and affects the accuracy of the steps followed by, when the objects are still in long periods. The second contribution regards the connected component labeling based on the contour tracking algorithm. Experimental results validate the effectiveness of the proposed approach. © 2010 IEEE.

关键词： Object recognition

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General capacity scaling of wireless networks

General capacity scaling of wireless networks

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IEEE Annual Joint Conference: INFOCOM, IEEE Computer and Communications Societies

作者： Cheng Wang Changjun Jiang Xiang-Yang Li Shaojie Tang Panlong Yang Key Laboratory of Embedded System and Service Computing Ministry of Education Shanghai China Department of Computer Science University of Tongji Shanghai China Department of Computer Science Illinois Institute of Technology Chicago IL USA TNLIST School of Software Tsinghua University China People''s Liberation Army University of Science and Technology China

We study the general scaling laws of the capacity for random wireless networks under the generalized physical model. The generality of this work is embodied in three dimensions denoted by (λ ∈ [1, n], n d ∈ [1, n], n s ∈ (1, n]). It means that: (1) We study the random network of a general node density λ ∈ [1, n], rather than only study either random dense network (RDN, λ = n) or random extended network (REN, λ = 1) as in the literature. (2) We focus on the multicast capacity to unify unicast and broadcast capacities by setting the number of destinations for each session as a general value n d ∈ [1, n]. (3)We allow the number of sessions changing in the range n s ∈ (1, n], rather than assume that n s = Θ(n) as in the *** derive the general lower bounds on the capacity for the arbitrary case of (λ, n d , n s ). Particularly, we show that for the special cases (λ = 1, n d ∈ [1, n], n s = n) and (λ = n, n d ∈ [1, n], n s = n), our schemes achieve the highest multicast throughputs proposed in the existing works.

关键词： Roads Routing Throughput Lattices Schedules Mathematical model

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Constructing prioritized interaction test suite with interaction relationship

Constructing prioritized interaction test suite with interac...

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2nd International Workshop on Education Technology and Computer Science, ETCS 2010

作者： Yuan, Jianjun Jiang, Zuowen Key Laboratory of Embedded System and Service Computing Ministry of Education of China Tongji University Shanghai China Department of Computer Science and Technology Key Laboratory of Embedded System and Service Computing Tongji University Shanghai China

ISBN: (纸本)9780769539874

Interaction testing has addressed some issues on how to select a small subset of test cases. In many systems where interaction testing is needed, the entire test suite is not executed because of time or budget constraints. It is important to prioritize the test cases in these situations. On the other hand, there are not always interactions among any factors in real systems. Moreover, some factors may need N-way (N>2) testing since there is a closer relationship among them. We present a model for prioritized interaction testing with interaction relationship and propose a greedy algorithm for generating variable strength covering arrays with bias. © 2010 IEEE.

关键词： Testing

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