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Geo-WDBMS: An improved DBMS with the function of watermarking geographical data

12th International Conference on Database systems for Advanced Applications, DASFAA 2007

作者： Min, Huang Xiang, Zhou Jiaheng, Cao Zhiyong, Peng Computer School Wuhan University Wuhan 430072 China State Key Lab. of Software Engineering Wuhan University Wuhan 430072 China

ISBN: (纸本)9783540717027

This paper focuses on the issue of geographical data's copyrights protection. A Geo-WDBMS has been built by embedding the watermarking functions into the inner code of the open source DBMS PostgreSQL. And its core watermarking mechanism is to insert and detect mark bits in the coordinates of the vertices in geographical objects using the methods of classifying and twice majority-voting. Further more, error correcting mechanism is used to enhance the resilience of the system and blind watermark is realized. Experiments on watermarking digital maps showed that the marked maps are inconspicuous and robust to various attacks. © Springer-Verlag Berlin Heidelberg 2007.

关键词： Database systems

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Replication strategy in unstructured peer-to-peer systems

Replication strategy in unstructured peer-to-peer systems

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21st International Parallel and Distributed Processing Symposium, IPDPS 2007

作者： Guofu, Feng Yuquan, Jiang Guihai, Chen Qing, Gu Sanglu, Lu Daoxu, Chen Nanjing Audit University School of Information Science Nanjing 210029 China State Key Lab. Novel Software Technology Nanjing 210093 China

ISBN: (纸本)1424409101

The unstructured Peer-to-Peer (P2P) systems usually use a "blind search " method to find the requested data object by propagating a query to a number of peers randomly. In order to increase the success rate of blind search, replication techniques are widely used in these systems. Most P2P systems replicate the most frequently accessed data objects to improve system performance. However, existing replication strategies cannot answer the question that how many replicas of an object should be kept in the P2P system. If an object is replicated excessively, it inevitably will affect the average efficiency of a replica, which will decrease the whole search performance. This paper addresses the issue of finding the proper number of replicas for an object according to its query rate. In this paper, we firstly investigate the precise relation among success rate, the allocation of replicas and query rate. Then we propose an approach of the allocation of copies to optimize the success rate. As a benchmark, our result offers a new understanding of replication. © 2007 IEEE.

关键词： Distributed computer systems

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Mesh deformation under skeleton-based detail-preservation

Mesh deformation under skeleton-based detail-preservation

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2007 10th IEEE International Conference on computer Aided Design and computer Graphics, CAD/Graphics 2007

作者： Wu, Jinzhong Liu, Xuehui Wu, Enhua State Key Lab. of Computer Science Institute of Software Chinese Academy of Sciences Beijing China Department of Computer and Information Science University of Macau Macao China Graduate University Chinese Academy of Sciences Beijing China

ISBN: (纸本)9781424415793

With in skeleton based deformation, two issues are waiting for investigation, large angle rotation and artifacts near joint regions. In this paper we propose rotation angle decomposition and detail preserving method to conquer them. A skeleton with multiple connected bones is prior computed for a triangle mesh. While deforming, large angle rotation is simulated by several progressive small angle rotations. We also introduce a distortion metric function E to quantify the difference between mesh edge vectors before and after deformation, preserving the detail of mesh surfaces. Nearby vertex position blending is enforced. We use sparse conjugate gradient method for the minimization of metric function E. Results show our method is suitable for 3D modeling and character animation applications, making the deformation near joint regions more natural. © 2007 IEEE.

关键词： Deformation

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Priority dropping for scalab.e video

International Journal of Multimedia and Ubiquitous Engineeri...

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International Journal of Multimedia and Ubiquitous Engineering 2007年第3期2卷 119-130页

作者： Xiaogang, Yang Jiqiang, Liu Ning, Li Kim, Tai-Hoon State Key Lab. of Software Development Env Beihang University Beijing China Dep. of Computer and Inf. Technology Beijing jiaotong University Beijing China Dept. of Multimedia Engineering Hannam University Daejeon Korea Republic of

For H.264/SVC, different layers or frames have different order of precedence according to their importance on video quality and the decoding process. Network should provide more protection for high priority layers or frames when SVC stream is transmitted over IP network. This paper proposes an active queue management algorithm based on priority dropping and PID algorithm, called PID_PD, which first drops the least important packets when network congestion arises. PID_PD implements differentiated service in IP layer to provide high quality video for end user. In addition, PID_PD does not create a side effect for the performance of control system. In this paper, we use BCC (Binomial Congestion Control) as source rate control protocol. BCC and PID_PD form a close-loop control system. By using a classic control theoretic approach to analyze the stability of the close-loop system, we present a method to decide the PID_PD parameters. Simulation shows PID_PD can protect important video data well, lower the disturbance of background flow, and decrease the packet loss rate of SVC flow.

关键词： Control systems

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The tilt cursor: Enhancing stimulus-response compatibility by providing 3D orientation cue of pen

Conference on Human Factors in Computing Systems - Proceedin...

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Conference on Human Factors in Computing systems - Proceedings 2007年 303-306页

作者： Tian, Feng Ao, Xiang Wang, Hongan Setlur, Vidya Dai, Guozhong Intelligence Engineering Lab. Institute of Software Chinese Academy of Sciences P.O.Box 8718 Beijing China State Key Lab. of Computer Science P.O.Box 8718 Beijing China Nokia Research Palo Alto 975 Page Mill Road Palo Alto CA United States

ISBN: (纸本)1595935932;9781595935939

In order to improve stimulus-response compatibility of touchpad in pen-based user interface, we present the tilt cursor, i.e. a cursor dynamically reshapes itself to providing the 3D orientation cue of pen. We also present two experiments that evaluate the tilt cursor?s performance in circular menu selection and specific marking menu selection tasks. Results show that in a specific marking menu selection task, the tilt cursor significantly outperforms the shape-fixed arrow cursor and the live cursor [4]. In addition, results show that by using the tilt cursor, the response latencies for adjusting drawing directions are smaller than that by using the other two kinds of cursors. © Copyright 2007 ACM.

关键词： Human computer interaction Sensory perception Three dimensional computer graphics Ubiquitous computing Menu selection task Stimulus response compatibility

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An access control model in lager-scale P2P file sharing systems

An access control model in lager-scale P2P file sharing syst...

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7th International Conference on Computational science (ICCS 2007)

作者： Yue Guang-xue Yu Fei Chen Li-ping Chen Yi-jun College of Information Engineering Jiaxing University 314000 China Department of Computer Science and Technology Huaihua University 418000 China State Key Lab. for Novel Software Technology Nanjing University 210093 China Jiangsu Provincial Key Laboratory of Computer Information Processing Technology Suzhou University 2150063 China

ISBN: (纸本)9783540725893

In lager-scale P2P file sharing systems, peers often must interact with unknown or unfamiliar peers without the benefit of trusted third parties or authorities to mediate the interactions. The decentralized and anonymous characteristics of P2P environments make the task of controlling access to sharing information more difficult. In this paper, we identify access control requirements and propose a trust based access control framework for P2P file-sharing systems. The model integrates aspects of trust and recommendation, fairness based participation schemes and access control schemes.

关键词： Distributed computer systems

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Approximation to the minimum rooted star cover problem

Approximation to the minimum rooted star cover problem

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4th International Conference on Theory and Applications of Models of Computation, TAMC 2007

作者： Wenbo, Zhao Peng, Zhang State Key Lab. of Computer Science Institute of Software Chinese Academy of Sciences P.O.Box 8718 Beijing 100080 China Graduate University Chinese Academy of Sciences Beijing China

ISBN: (纸本)3540725032

In this paper, we study the following minimum rooted star cover problem: given a complete graph G = (V, E) with a length function l : E &rarr + that satisfies the triangle inequality, a designated root vertex r ∈ V, and a length bound D, the objective is to find a minimum cardinality set of rooted stars, that covers all vertices in V such that the length of each rooted star is at most D, where a rooted star is a subset of E having a common center s S V and containing the edge (r, s). This problem is NP-complete and we present a constant ratio approximation algorithm for this problem. Springer-Verlag Berlin Heidelberg 2007.

关键词： Computational geometry

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A new group rekeying scheme based on t-packing designs for ad hoc networks 2

A new group rekeying scheme based on t-packing designs for a...

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2nd International Conference on Scalab.e Information systems, InfoScale 2007

作者： Chen, Jianwei Xu, Li Mu, Yi Key Lab. of Network Security and Cryptology Fujian Normal University Fuzhou350007 China School of Computer Science and Software Engineering University of Wollongong WollongongNSW2522 Australia

ISBN: (纸本)9781595937575

Secure group key distribution and efficient rekeying is one of the most challenging security issues in ad hoc networks at present. In this paper, Latin squares are used to construct orthogonal arrays in order to quickly obtain t-packing designs. Based on cover-free family properties, t-packing designs are adopted in key predistribution phase. Then the pre-deployed keys are used for implementing secure channels between members for group key distribution. The new scheme improves the collusion-resilience of the networks using the cover-free family properties, and enhances the key-sharing connectivity of nodes which makes key management more efficient. This paper also presents in depth theory and data analysis of the new scheme in terms of network security and connectivity.1 Copyright 2007 ACM.

关键词： Ad hoc networks

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An energy-aware protocol for data gathering applications in wireless sensor networks

An energy-aware protocol for data gathering applications in ...

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IEEE International Conference on Communications (ICC 2007)

作者： Liu, Ming Zheng, Yuan Cao, Jiannong Chen, Guihai Chen, Lijun Gong, Haigang School of Computer Science and Engineering University of Electronic and Technology of China China Internet and Mobile Computing Lab. Department of Computing Hong Kong Polytechnic University Hong Kong State Key Laboratory for Novel Software Technology Nanjing University China

ISBN: (纸本)9781424403523

Data gathering is a major function of many applications in wireless sensor networks (WSNs). The most important issue in designing a data gathering algorithm is how to save energy of sensor nodes while meeting the requirement of applications/users such as sensing area coverage. In this paper, we propose a novel hierarchical clustering protocol for long-lived sensor network. EAP achieves a good performance in terms of lifetime by minimizing energy consumption for in-network communications and balancing the energy load among all nodes. EAP introduces a new clustering parameter for cluster head election, which can better handle the heterogeneous energy capacities. Furthermore, it also introduces a simple but efficient approach, namely intra-cluster coverage to cope with the area coverage problem. We evaluate the performance of the proposed protocol using a simple temperature sensing application. Simulation results show that our protocol significantly outperforms LEACH and HEED in terms of network lifetime and the amount of data gathered.

关键词： Network protocols

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A kind of shape similarity measure methods and the performance evaluation

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Journal of Computational Information systems 2007年第5期3卷 2057-2062页

作者： Hong, Zhiling Wang, Beizhan Jiang, Qingshan Wang, Shoujue Department of Computer Science Xiamen University Fujian 361005 China School of Software Xiamen University Fujian 361005 China Key Laboratory for Intelligent Information Technology Fujian 361005 China Lab. of Artificial Neural Networks Inst. of Semiconductors CAS Beijing 100083 China

Shape similarity measure is an important and difficult problem in computer vision and has been extensively studied for decades. In this paper, we propose a kind of shape similarity measure methods based on partition block statistic According to the difference of partition methods, we extend the idea into eight shape similarity measure methods. Zernike moments and Hu moments methods are also included for performance comparison. Shape retrieval experiments have been conducted on the MPEG-7 Core Experiment CE-Shape-1 database of 1400 images which illustrate the performance of the ten algorithms.

关键词： computer vision

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