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A DAG-based algorithm of mining frequent closed itemsets in high dimensional datasets

International Journal of Advancements in Computing technology 2012年第19期4卷 213-222页

作者： Dong, Jun Chen, Shuai Chen, Jing Huang, Guoyan Ren, Jiadong College of Information Science and Engineering Yanshan University 066004 China The Key Laboratory for Computer Virtual Technology and System Integration of Hebei Province Qinhuangdao City 066004 China Production Management Department Shanghai Aircraft Manufacturing Co.Ltd 200436 China

Algorithms based on row enumeration always scan and construct conditional transposed tables, which increases the execution time and space cost. To address this problem, we adopt the DAG (Directed Acyclic Graph) to compress the dataset to save the memory space. In DAG, each node is related to a rowid, and each two nodes have a corresponding directed edge which stores the common items of the two rowids. Each row is given an integer according to its coming order and the DAG follows that order. A directed acyclic graph records the relation between rows and items by doing AND(&) operation with the nodes' binary code of the edges. We also present DAGHDDM which is a new approach for mining frequent closed itemsets in high dimensional datasets. In this algorithm, we adopt the BitTable to compress the dataset firstly, and then construct DAG according to the BitTable. We increase the same items of the adjacent edges to implement pattern growth, traverse the DAG in reversal way and adopt a close-checking method to generate all frequent closed itemsets. It scans the dataset only once and does not generate candidate itemsets. The experimental results show that the proposed DAGHDDM algorithm can decrease the cost of time.

关键词： Directed graphs

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Analysis on Token-Controlled Public key Encryption

Analysis on Token-Controlled Public Key Encryption

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International Conference on Mobile Ad-hoc and Sensor Networks, MSN

作者： Changlu Lin Yong Li Sriramkrishnan Srinivasan Li Lu Key Laboratory of Network Security and Cryptology Fujian Normal University Fuzhou China Key Laboratory of Communication & Information Systems Beijing Municipal Commission of Education Beijing Jiaotong University Beijing China Department of Computing University of Surrey Guildford UK School of Computer Science University of Electronic Science and Technology Chengdu China

ISBN: (纸本)9781467358088

In this paper, we analyze on the use of token-controlled public key encryption (TCE)schemes. We argue that for many of the applications in some possibilities of application in financial or legal scenarios, for example, the millionaire's will problem, the `private-opening' commitment, the scheduled payment problem, and the sealed-bid auctions and electronic lotteries problem, in the literature, the use of token-controlled public key encryption on its own, leads to inadequate solutions. We suggest that when considering applications of TCE, it is advisable to pay close attention to the lack of authentication and incorporate defences against the problems highlighted in this paper.

关键词： Public key encryption Token-controlled public key encryption Authentication security and privacy Public key encryption Authentication Trichloroethylene

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A knowledge passing process calculus

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ICIC Express Letters 2012年第1期6卷 85-90页

作者： Qian, Zhongmin Cao, Zining Gao, Zhifeng Lin, Jinxing Department of Computer Science and Technology Nanjing University of Aeronautics and Astronautics No. 29 Yudao Street Baixia District Nanjing 210016 China Provincial Key Laboratory for Computer Information Processing Technology Soochow University No. 1 Shizi Street Suzhou 215006 China National Key Laboratory of Science and Technology on Avionics System Integration Shanghai 200233 China College of Automation Nanjing University of Posts and Telecommunications No. 9 Wenyuan Road Yadongxincheng District Nanjing 210046 China

In MAS (Multi-Agent system), communicating among agents is an important characteristic as it is important in transmitting information among agents, recognizing the status changing, and scheduling and accomplishing cooperation tasks. Different from the research in the field of computer science or others, communicating is to transmit knowledge in MAS. The existed works about transmitting knowledge were seldom. This paper proposed a knowledge passing process calculus based on Robin Milner's CCS and studied its semantic features. This work constructs a fundament for the further developing of MAS formal semantics. © 2012 ISSN 1881-803X.

关键词： Multi agent systems

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Improvement on masked S-box hardware implementation

Improvement on masked S-box hardware implementation

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International Conference on Innovations in information technology

作者： Juanli Zeng Yi Wang Cheng Xu Renfa Li College of Information Science and Engineering Hunan University Changsha Hunan P. R. China Department of Electrical & Computer Engineering National University of Singapore Singapore Hunan Province Key Laboratory of Network and Information Security

Masking in gate level could efficiently protect AES S-box out of power analysis attack. But there still exists a kind of attack, called glitch attack, to achieve the sensitive information from gate cell leakage. Some works had been done to resist against glitch attack, which carefully masked AND gate or used Wave Dynamic Differential Logic (WDDL) cell. In this paper, we propose an improved masked AND gate, in which the relationship between input masked values and masks is nonlinear. Usually, when converting S-box operations from GF(2 8 ) to GF(((2 2 ) 2 ) 2 ), all the necessary computations become XOR and AND operations. Therefore, to fully mask AES S-box is to substitute the unmasked XOR and AND operations with the proposed masked AND gate and protected XOR gate. Although the proposed masked AND gate take up one extra XOR gate than Trichina's design and Baek's design, it can resist against glitch attack without using specific gate cell, such as WDDL.

关键词： Logic gates Hardware CMOS integrated circuits Encryption Field programmable gate arrays computer architecture

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Time-domain preamble-based SNR estimation for OFDM systems in doubly selective channels

Time-domain preamble-based SNR estimation for OFDM systems i...

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MILCOM, Military Communications Conference

作者： Fan Yang Xi Zhang Zhong-pei Zhang School of Communication and Information Engineering University of Electronic Science and Technology of China Chengdu China Networking and Information Systems Laboratory Department of Electrical and Computer Engineering Texas A and M University College Station TX USA National Key Laboratory of Science and Technology on Communications University of Electronic Science and Technology of China Chengdu China

In wireless orthogonal frequency division multiplexing (OFDM) systems, the knowledge of signal-to-noise ratio (SNR) plays an important role for system optimization. Most of the exiting literatures have studied the SNR estimation for perfect synchronization in additive white Gaussian noise (AWGN) channels, or in frequency selective channels. However, the realistic channels are always doubly selective, and there may exist some residual symbol timing offset (STO) and carrier frequency offset (CFO) after coarse synchronization in the time domain. In this paper, we take these into account and propose a time-domain average SNR estimation scheme using one OFDM training symbol (preamble) which has been divided into multiple parts with equal length. Compared with the timedomain low-complexity SNR estimator (TLSE), our proposed time-domain preamble-based SNR estimator (TPSE) can not only be implemented in the presence of STO and CFO, but also generate more accurate SNR estimation for the channels with large Doppler shift. The estimated SNR value based on our scheme in the time-domain can be further reused to improve the ensuing CFO estimation and fine synchronization efficiently.

关键词： Signal to noise ratio OFDM Estimation Time domain analysis Channel estimation Training Synchronization

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Overhead Power Line Detection from UAV Video Images

Overhead Power Line Detection from UAV Video Images

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International Conference on Mechatronics and Machine Vision in Practice

作者： Tang Wen YANG Hang YIN Qiu Qi RUAN Jian Da HAN Jun Tong QI Qing YONG Zi Tong WANG Zeng Qi SUN Beijing Key Laboratory of Advanced Information Science and Network Technology Institute of Information Science Beijing Jiaotong University Beijing 100044 China Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong University Beijing 100044 China State Key Laboratory of Robotics Shenyang Institute of Automation CAS Shenyang 110016 China Department of Computer Science and Technology Tsinghua University Beijing 100084 China

ISBN: (纸本)9781467316439

Currently, unmanned aerial vehicles (UAVs) are applied to routine inspection tasks of electric distribution networks. As an important information source, machine vision attracts much attention in the area of the UAV's autonomous control. To this end, real-time algorithms are studied-in this paper to detect the power lines in the UAV video images. First, video images are converted into binary images through an adaptive thresholding approach. Then, Hough Transform is used to detect line candidates in the binary images. Finally, a fuzzy C- means (FCM) clustering algorithm is used to discriminate the power lines from the detected line candidates. The properties of power lines are used to remove the spurious lines, and the length and slope of the detected lines are used as features to establish the clustering data set. Experimental results show that the algorithms proposed are effective and able to tolerate noises from complicated terrain background and various illuminations.

关键词： Hough transforms autonomous aerial vehicles computer vision fuzzy set theory pattern clustering power overhead lines power system control video signal processing

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Hyperspectral image classification using band selection and morphological profile

Hyperspectral image classification using band selection and ...

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Workshop on Hyperspectral Image and Signal Processing: Evolution in Remote Sensing, WHISPERS

作者： Kun Tan Erzhu Li Qian Du Peijun Du Jiangsu Key laboratory of Resources and Environment Information Engineering China University of Mining and Technology China Department of Electrical and Computer Engineering Mississippi State University USA Department of Geographical Information Science Nanjing University China

In this paper, we propose a new methodology to combine spectral information and spatial features for Support Vector Machine (SVM)-based classification. The novelty of the proposed work is in the combination of band selection (i.e., linear prediction (LP)-based method), spatial feature extraction (i.e., morphology profiles (MP)), and spectral transformation (i.e., principal component analysis (PCA)) to build a computationally tractable system. The preliminary result with ROSIS data shows that using the selected bands and MP features extracted from principal components (PCs) can yield the highest accuracy. We believe such finding is instructive to feature extraction/selection for spectral/spatial-based hyperspectral image classification.

关键词： Abstracts Indexes Accuracy Statistical learning Hyperspectral imaging

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Feasibility of Double-Click Attack on a Passive Detection Quantum key Distribution system

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Chinese Physics Letters 2011年第7期28卷 27-30页

作者： ZHANG Peng LI Chao Department of Mathematics and System Science Science CollegeNational University of Defense TechnologyChangsha 410073 State Key Laboratory of Information Security Institute of SoftwareChinese Academy of SciencesBeijing 100190

An eavesdropper(Eve)can exploit all the imperfections of a practical quantum key distribution(QKD)system to obtain some information about the secret key,no matter whether these imperfections are from the physical layer or from the post-processing *** propose a possible attack on a passive detection QKD system based on the imperfection from the software *** analysis shows that Eve can obtain all the information about the key without being discovered.

关键词： layer system quantum

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Optimal Beaconing Control for Epidemic Routing in Delay-Tolerant Networks

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IEEE Transactions on Vehicular technology 2012年第1期61卷 311-320页

作者： Yong Li Zhaocheng Wang Depeng Jin Li Su Lieguang Zeng Sheng Chen State Key Laboratory on Microwave and Digital Communications Tsinghua National Laboratory for Information Science and Technology Department of Electronic Engineering Tsinghua University Beijing China Department of Electronics and Computer Science Faculty of Physical and Applied Sciences University of Southampton Southampton UK Faculty of Engineering King Abdulaziz University Jeddah Saudi Arabia

Owing to the uncertainty of transmission opportunities between mobile nodes, the routing in delay-tolerant networks (DTNs) exploits the mechanism of opportunistic forwarding. Energy-efficient algorithms and policies for DTN are crucial to maximizing the message delivery probability while reducing the delivery cost. In this contribution, we investigate the problem of energy-efficient optimal beaconing control in a DTN. We model the message dissemination under variable beaconing rate with a continuous-time Markov model. Based on this model, we then formulate the optimization problem of the optimal beaconing control for epidemic routing and obtain the optimal threshold policy from the solution of this optimization problem. Furthermore, through extensive numerical results, we demonstrate that the proposed optimal threshold policy significantly outperforms the static policy with constant beaconing rate in terms of system energy consumption savings.

关键词： Energy consumption Routing Optimization Markov processes Simulation Computational modeling Ad hoc networks

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Reconstructing 3D human poses from uncalibrated monocular images with strong perspective effects

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Journal of Computational information systems 2012年第15期8卷 6437-6445页

作者： Chen, Shu Peng, Xiaoning School of Information Engineering Xiangtan Universtiy Xiangtan 411105 China Key Laboratory of Intelligent Computing and Information Processing Ministry of Education Xiangtan 411105 China School of Information Science and Engineering Central South University Changsha 410083 China Department of Computer Science and Technology Huaihua College Huaihua 418008 China

This paper present a geometric method to reconstruct human motion pose from 2D point correspondences obtained from uncalibrated monocular images. The proposed algorithm can handle images with very strong perspective effects, which is guaranteed by the fact that only one scale factor corresponding to the root joint in the skeleton model is required estimating. To take fully advantage of this fact, a system of two nonlinear equations with two variables to estimate the scale factor of the root joint is established, and the scale factor of the root joint is optimized by the Gauss-Newton iterative scheme. At last, a framework to reconstruct human motion pose is presented. Quantitive analysis of the experiment results based on several real monocular video sequences shows the accuracy of the scale factor as well as the accuracy of the pose reconstruction. © 2012 Binary information Press.

关键词： Nonlinear equations

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