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Formal definition method of denotational semantics and functions for PLC program language

Zhongnan Daxue Xuebao (Ziran Kexue Ban)/Journal of Central South University (science and technology) 2011年第SUPPL. 1期42卷 1107-1113页

作者： Xiao, Li-Tian Gu, Ming Sun, Jia-Guang National Laboratory for Information Science and Technology School of Software Tsinghua University Beijing 100084 China Key Laboratory for Information System Security of Ministry of Education Department of Computer Science and Technology Tsinghua University Beijing 100084 China Beijing Special Engineering Design and Research Institute Beijing 100028 China

In order to verify the correctness of PLC programs by formal methods, the definition of denotational semantics on PLC program language was studied to achieve PLC programs modeling and model checking. Based on the extended λ-calculus definition, the configuration of PLC program architecture, denotational semantics of PLC programs and functions of denotational semantics were defined, which proves the basis of model checking and theorem.

关键词： Model checking

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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 effective control scheme to ensure real-time causal order in large-scale distributed interactive simulations

An effective control scheme to ensure real-time causal order...

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International Conference on Communication Software and Networks, ICCSN

作者： Hangjun Zhou Sha Fu Key Laboratory of Science and Technology for National Defence of Parallel and Distributed Processing School of Computer Science National University of Defense Technology Changsha Hunan China Department of Information Management Hunan University of Finance and Economics Changsha Hunan China

When a large-scale distributed interactive simulation system is running on WAN, the sites usually disperse over a wide area in geography, which results in the simulation clock of each site is hardly to be accurately synchronized with that of other sites. The asynchronous clocks and large transmission latency on WAN bring on a problem for the large-scale simulations to preserve the real-time causal order delivery of received events at each site. In this article, we analyze the indirect way to compare the values of asynchronous simulation clocks at first, and then propose a novel scheme which can select the reconstructible causal control information for each message so as to ensure the causal ordering of events in real time. Experiments demonstrate that the scheme can weaken the effect of network latency, reduce the overhead of the transmission amount of control information and improve the causal order consistency in asynchronous distributed simulations.

关键词： Clocks Educational institutions

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A geometric distortion resilient image watermark algorithm based on DWT-DFT

Journal of Software

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Journal of Software 2011年第9期6卷 1805-1812页

作者： Hu, Yuping Wang, Zhijian Liu, Hui Guo, Guangjun Guangdong Province Key Lab of EC Market Application Technology GuangDong University of Business Studies Guangzhou 510320 China Hangzhou Key Lab of E-Business and Information Security Hangzhou Normal University Hangzhou 310036 China Department of Electronics and Communication Engineering Changsha College Changsha Hunan 410003 China Department of Computer Science and Technology Hunan Institute of Humanities Science and Technology Loudi Hunan 41700 China

In this paper, a robust watermarking algorithm against geometric distortions and common signal processing is proposed. This algorithm is based on two method to solve the synchronization of the original watermarking images and test images in the wavelet domain watermarking. One method, which estimates rotation and scaling based on embedding a template in a circle of middle frequency in DFT, One method which estimates translation based on extracting an invariant centroid from a restricted area inside the image. In the embedding process, a watermark is embedded adaptively in low band of DWT domain, according to the conceal quality of Human Visual system (HVS).The experiment results show robustness against common signal processing attacks, several geometric distortions and some combination attacks, Also the comparison with the prior algorithms shows the better performance of the proposed algorithm. © 2011 ACADEMY PUBLISHER.

关键词： Geometry

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A multi-class pattern recognition method for motor imagery EEG data

A multi-class pattern recognition method for motor imagery E...

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IEEE International Conference on systems, Man and Cybernetics

作者： Yonghui Fang Minyou Chen Robert F Harrison State Key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing University Chongqing China School of Electronic and Information Engineering Southwest University Chongqing China Department of Automatic Control & Systems Engineering University of Sheffield Sheffield UK

The Common Spatial Patterns (CSP) algorithm is useful for calculating spatial filters for detecting event-related desynchronization (ERD) for use in ERD-based brain-computer interfaces (BCIs). However, basic CSP is a supervised algorithm suited only to two-class discrimination; it is unable to solve multiclass discrimination problems. This paper proposes a new method named the binary common spatial patterns (BCSP) algorithm to extend the basic CSP method to multi-class recognition. Our method arranges the spatial filters and Fisher classifiers in the form of a binary tree whereby N - 1 spatial filters and N - 1 Fisher classifiers are calculated for N class recognition. This is fewer than must be calculated in other methods (e.g. one-versus-rest, OVR). This makes the overall classification procedure less redundant. Simulation results show that BCSP has better performance than the OVR scheme and outperforms the three best teams in the 2008 BCI-competition.

关键词： Spatial filters Arrays Feature extraction Electroencephalography Band pass filters Covariance matrix Filtering algorithms

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Research of the Middleware Based Quality Management for Context-Aware Pervasive Applications

Research of the Middleware Based Quality Management for Cont...

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International Conference on computer and Management (CAMAN)

作者： Di Zheng Hang Yan Jun Wang Department of Computer Science Naval University of Engineering Wuhan Hubei China Department of Electronics and Information Engineering Huazhong University of Science and Technology Wuhan Hubei China Key Research Laboratory Wuhan Radar Institute Wuhan Hubei China

With the rapid development of the information technology, it is inevitable that the distributed mobile computing will evolve to the pervasive computing gradually whose final goal is fusing the information space composed of computers with the physical space in which the people are working and living in. To achieve this goal, one of the problems is how to continuously monitor/capture and interpret the environment related information efficiently to assure high context awareness. Many attentions have been paid to the research of the context-aware pervasive applications. However, most of them just use the raw context directly or take just some aspects of the Quality of Context (QoC) into account. Therefore, we propose a middleware based context-aware framework that support QoC management in various layers. By this framework we can refinery raw context, discard duplicate and inconsistent context so as to protect and provide QoS-enriched context information of users to context-aware applications and services.

关键词： Context Middleware security Algorithm design and analysis Context modeling Ontologies Sensors

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Visual saliency detection by spatially weighted dissimilarity

Visual saliency detection by spatially weighted dissimilarit...

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Conference on computer Vision and Pattern Recognition (CVPR)

作者： Lijuan Duan Chunpeng Wu Jun Miao Laiyun Qing Yu Fu College of Computer Science and Technology Beijing University of Technology Beijing China Key Laboratory of Intelligent Information Processing Institute of Computing Technology Chinese Academy and Sciences Beijing China School of Information Science and Engineering Chinese Academy and Sciences Beijing China Department of Computing University of Surrey Guildford Surrey UK

In this paper, a new visual saliency detection method is proposed based on the spatially weighted dissimilarity. We measured the saliency by integrating three elements as follows: the dissimilarities between image patches, which were evaluated in the reduced dimensional space, the spatial distance between image patches and the central bias. The dissimilarities were inversely weighted based on the corresponding spatial distance. A weighting mechanism, indicating a bias for human fixations to the center of the image, was employed. The principal component analysis (PCA) was the dimension reducing method used in our system. We extracted the principal components (PCs) by sampling the patches from the current image. Our method was compared with four saliency detection approaches using three image datasets. Experimental results show that our method outperforms current state-of-the-art methods on predicting human fixations.

关键词： Humans Color Visualization Image color analysis Principal component analysis Correlation Computational modeling

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New Constructions for Identity-Based Unidirectional Proxy Re-Encryption

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Journal of computer science & technology 2010年第4期25卷 793-806页

作者：赖俊祚朱文涛邓慧杰刘胜利寇卫东 Department of Computer Science and Enqineering Shanghai Jiao Tong University School of Information Systems Singapore Management University State Key Laboratory of Information Security Graduate University of Chinese Academy of Sciences School of Computer Science and Technology Xidian University

We address the cryptographic topic of proxy re-encryption （PRE）, which is a special public-key cryptosystem. A PRE scheme allows a special entity, known as the proxy, to transform a message encrypted with the public key of a delegator （say Alice）, into a new ciphertext that is protected under the public key of a delegatee （say Bob）, and thus the same message can then be recovered with Bob＇s private key. In this paper, in the identity-based setting, we first investigate the relationship between so called mediated encryption and unidirectional PRE. We provide a general framework which converts any secure identity-based unidirectional PRE scheme into a secure identity-based mediated encryption scheme, and vice versa. Concerning the security for unidirectional PRE schemes, Ateniese et al. previously suggested an important property known as the master secret security, which requires that the coalition of the proxy and Bob cannot expose Alice＇s private key. In this paper, we extend the notion to the identity-based setting, and present an identity-based unidirectional PRE scheme, which not only is provably secure against the chosen eiphertext attack in the standard model but also achieves the master secret security at the same time.

关键词： identity-based encryption （IBE） unidirectional proxy re-encryption mediated encryption （mE） chosen ci-phertext attack （CCA） master secret security （MSS）.

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A Trust-Personality Mechanism for Emotion Compensation

A Trust-Personality Mechanism for Emotion Compensation

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International Conference on Advanced Learning Technologies (ICALT)

作者： Jiwei Qin Qinghua Zheng Feng Tian Department of Computer Science and Technology Xi'an Jiaotong University Xi'an China Xi'an Jiaotong University Xi'an Shaanxi CN Ministry of Education Key Laboratory for Intelligent Networks and Network Security Xi'an Jiaotong University Xi'an China

E-learning provides an unprecedented flexibility and convenience for learners via breaking the limitation of space-time. Most researchers are only concerned about the learner's cognitive and construct a great amount of substantive digital learning resources, however they neglect of the learners' affect in current e-learning systems. In this paper, we focus primarily on the negative affect of learners, and propose an emotion compensation mechanism associated with trust and personality traits in traditional recommender technology. First, we analyze the difference between emotion compensation and traditional recommender. Next, the score of trust is calculated with historical behavior, otherwise depend on similarity of personality traits without historical experience. We use trustworthiness to replace similarity as prediction weight in trust filtering process. At last we do experiments with data collected in previous system named emotion-chatting. Compared with results of experiments between traditional recommender and trust-personality recommender, the average of accuracy is improved 4 points in percentage.

关键词： Recommender systems Electronic learning Accuracy Internet Psychology Context

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An utility-based job scheduling algorithm for Cloud computing considering reliability factor

An utility-based job scheduling algorithm for Cloud computin...

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International Conference on Cloud and Service Computing (CSC)

作者： Bo Yang Xiaofei Xu Feng Tan Dong Ho Park State Key Laboratory of Software Engineering Wuhan University of China Wuhan China School of Computer Science and Engineering University of Electronic Science and Technology Chengdu China Department of Industrial Engineering University of Electronic Science and Technology Chengdu China Department of Information and Statistics Hallym University Chuncheon South Korea

Cloud computing' service-oriented characteristics advance a new way of service provisioning called utility based computing. However, toward the practical application of commercialized Cloud, we encounter two challenges: i) there is no well-defined job scheduling algorithm for the Cloud that considers the system state in the future, particularly under overloading circumstances; ii) the existing job scheduling algorithms under utility computing paradigm do not take hardware/software failure and recovery in the Cloud into account. In an attempt to address these challenges, we introduce the failure and recovery scenario in the Cloud computing entities and propose a Reinforcement Learning (RL) based algorithm to make job scheduling fault-tolerable while maximizing utilities attained in the long term. We carry out experimental comparison with Resource-constrained Utility Accrual algorithm (RUA), Utility Accrual Packet scheduling algorithm (UPA) and LBESA to demonstrate the feasibility of our proposed approach.

关键词： Scheduling algorithms Reliability Cloud computing Scheduling Computational modeling Approximation methods

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