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International Conference on Management of E-Commerce and E-Goverment

作者： Wu, Shihan Liu, Dexi Jiao, Xianpei Jiangxi Key Laboratory of Data and Knowledge Engineering School of Information Technology Jiangxi University of Finance and Economics Nanchang Jiangxi China

ISBN: (纸本)9780769542454

XML Retrieval is becoming the focus study of the field of information Retrieval and database. Summarization of the results which come from the XML search engines will alleviate the read burden of user's. However, as the basis of this study, the construction of the query-oriented XML text summarization corpus has not yet received enough attention. In this paper, we introduce our works on constructing this kind of corpus, including the selection of topics and XML elements/documents, construction process and the feature of the constructed corpus. Up to now, the corpus has 25 English query topics, including 422 elements for summarization, and 32 Chinese topics which including 402 elements. For each topic, 4 pieces of extracted summaries and 4 pieces of generated summaries are made manually by 4 experts. © 2010 IEEE.

关键词： XML

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基于划分的集合相似连接

基于划分的集合相似连接

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第29届中国数据库学术会议

作者： Rong Chuitian 荣垂田 Xu Tianren 徐天任 Du Xiaoyong 杜小勇 Key Laboratory of Data Engineering and Knowledge Engineering(Renmin University of China) Ministry o 教育部数据工程与知识工程重点实验室(中国人民大学) 北京 100872 中国人民大学信息学院北京 100872 School of Information Renmin University of China Beijing 100872 Key Laboratory of Education Inform 中国人民大学信息学院北京 100872 民族教育信息化教育部重点实验室(云南师范大学) 昆明 650500

集合相似连接(set similarity join)是指在给定的数据集中，按照基于集合间覆盖关系的相似度计算方法来衡量数据之间的相似度、并找出所有相似度不小于给定阈值的数据对的操作。集合相似连接作为一种新的基本操作在很多领域中有重要应... 详细信息

集合相似连接(set similarity join)是指在给定的数据集中，按照基于集合间覆盖关系的相似度计算方法来衡量数据之间的相似度、并找出所有相似度不小于给定阈值的数据对的操作。集合相似连接作为一种新的基本操作在很多领域中有重要应用。随着社会网络、移动应用以及在线服务的发展，使得数据收集的效率和规模得到了很大的提高，同时给相似连接操作带来新的挑战。根据集合相似的必要条件，提出了相似集合之间的差异度。利用差异度和鸽巢原理，提出了一种新颖的基于数据划分的集合相似连接计算方法，该方法对集合进行自适应的均衡划分，并利用基于划分块的过滤方法来提高过滤的效率。为了进一步提高过滤的效果和相似连接的效率，利用划分块的位置信息提出了增强的过滤方法。针对提出的方法，在不同的环境下进行了实验，实验结果表明，该方法与已有的方法相比可以有效地提高相似连接的效率。

关键词：数据库集合相似连接均衡划分法阈值

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Constant approximation for virtual backbone construction with Guaranteed Routing Cost in wireless sensor networks

Constant approximation for virtual backbone construction wit...

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

作者： Hongwei Du Qiang Ye Weili Wu Wonjun Lee Deying Li Dingzhu Du Stephen Howard Department of Computer Science and Information Technology University of Prince Edward Island Canada Department of Computer Science University of Texas Dallas USA Department of Computer Science and Engineering Korea University Seoul South Korea Key Laboratory of Data Engineering and Knowledge Engineering MOE Renmin University of China China

ISBN: (纸本)9781424499199

In wireless sensor networks, virtual backbone construction based on connected dominating set is a competitive issue for routing efficiency and topology control. Assume that a sensor networks is defined as a connected unit disk graph (UDG). The problem is to find a minimum connected dominating set of given UDG with minimum routing cost for each node pair. We present a constant approximation scheme which produces a connected dominating set D, whose size |D| is within a factor α from that of the minimum connected dominating set and each node pair exists a routing path with all intermediate nodes in D and with length at most 5 · d(u,v), where d(u,v) is the length of shortest path of this node pair. A distributed algorithm is also provided with analogical performance. Extensive simulation shows that our distributed algorithm achieves significantly than the latest solution in research direction.

关键词： Routing Approximation methods Distributed algorithms Wireless sensor networks Polynomials Computer science Electronic mail

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Signal sparse representation based on the peak transform and modulus maximum of wavelet coefficients

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Tamkang Journal of Science and engineering 2011年第3期14卷 217-224页

作者： Cen, Yi-Gang Xin, Rui Chen, Xiao-Fang Cen, Li-Hui Hu, Ming-Xing Chen, Shi-Ming Institute of Information Science Beijing Jiaotong University Beijing 100044 China Beijing Key Laboratory of Advanced Information Science and Network Technology Beijing 100044 China School of Information Science and Engineering Central South University Hunan Changsha 410083 China Centre for Medical Image Computing University College London United Kingdom School of Electrical and Electronic Engineering East China Jiao Tong University Jiangxi Nanchang 330013 China

It is now well-known that one can reconstruct sparse or compressible signals accurately from a very limited number of measurements. This technique is known as "compressed sensing" or "compressive sampling" (CS). A basic requirement of CS is that a signal should be sparse or it can be sparsely represented in some orthogonal bases. Based on the Peak Transform (PT) and modulus maximum of wavelet coefficients, a new algorithm was proposed for the signals that are non-sparse themselves and can not be sparsely represented by wavelet transform such as the Linear Frequency Modulated signal. According to this algorithm, K-sparse wavelet coefficients can be obtained. For the peak sequence produced by the Peak Transform, value expansion approach of reversible watermarking is exploited such that the peak sequence can be embedded into the measurements of the signal, which avoids increasing additional points for transmission. By using the Peak Transform and modulus maximum, non-sparse wavelet coefficients can be transformed into K-sparse coefficients, which improves the reconstruction result of CS. Simulation results showed that our proposed algorithm achieved better performance comparing with the original CS algorithm.

关键词： Compressed sensing

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Approximation for a scheduling problem with application in wireless networks

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Science China Mathematics 2010年第6期53卷 1643-1655页

作者： ZHU QingHua & LI DeYing key laboratory of data engineering and knowledge engineering,MOE,school of information,Renmin University of China,Beijing 100872,China 1. Key Laboratory of Data Engineering and Knowledge Engineering MOE School of Information Renmin University of China Beijing 100872 China

A network of many sensors and a base station that are deployed over a region is *** sensor has a transmission range,an interference range and a carrier sensing range,which are r,αr and βr,*** this paper,we study the minimum latency conflict-aware many-to-one data aggregation scheduling problem:Given locations of sensors along with a base station,a subset of all sensors,and parameters r,α and β,to find a schedule in which the data of each sensor in the subset can be transmitted to the base station with no conflicts,such that the latency is *** designe an algorithm based on maximal independent sets,which has a latency bound of(a+19b)R + Δb-a + 5 time slots,where a and b are two constant integers relying on α and β,Δ is the maximum degree of network topology,and R is the trivial lower bound of *** Δ contributes to an additive factor instead of a multiplicative one,thus our algorithm is nearly a constant(a+19b)-ratio.

关键词： approximation algorithm conflict-aware many-to-one data aggregation latency wireless sensor network

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应用数据填充缓解稀疏问题实现个性化推荐

应用数据填充缓解稀疏问题实现个性化推荐

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第18届全国信息存储技术学术会议

作者： Xia Jian-xun 夏建勋 Wu Fei 吴非 Xie Chang-sheng 谢长生湖北工程学院计算机与信息科学学院湖北孝感 432000 School of Computer Science and Technology Huazhong University of Science and Technology Hubei Wuhan 430074 武汉国家光电实验室湖北武汉 430074 Key Laboratory of Data Storage Systems Ministry of Education of China Hubei Wuhan 430074 School of Computer Science and Technology Huazhong University of Science and Technology Hubei Wuhan 430074 信息存储系统教育部重点实验室湖北武汉 430074 华中科技大学计算机科学与技术学院湖北武汉 430074 Wuhan National Laboratory for Optoelectronics Hubei Wuhan 430074 School of Computer and Information Science Hubei Engineering University Hubei Xiaogan 432000

协同过滤是到目前为止最成功和应用最广泛的推荐技术，然而，由于用户-项目矩阵极端稀疏导致推荐不精确.针对该问题，本文提出了三种数据填充方法和两种推荐策略.对评分矩阵中未评分数据的三种数据填充方法是：(1)采用行和列数据的加权... 详细信息

协同过滤是到目前为止最成功和应用最广泛的推荐技术，然而，由于用户-项目矩阵极端稀疏导致推荐不精确.针对该问题，本文提出了三种数据填充方法和两种推荐策略.对评分矩阵中未评分数据的三种数据填充方法是：(1)采用行和列数据的加权平均值填充；(2)采用行和列数据的众数的平均值填充；(3)采用行和列数据的中位数的平均值填充.一种推荐策略是直接用填充数据作为预测评分进行推荐；另一种推荐策略是将填充数据后的评分矩阵作为伪评分矩阵应用Pearson相关相似性进行协同过滤推荐.采用GroupLens数据集进行的实验结果表明：上述几种推荐策略均可有效地缓解评分数据稀疏性问题，提高推荐精确度.从平均的预测精确度来看，直接采用三种填充数据作为预测评分进行推荐比传统的基于Pearson相关相似性的协同过滤推荐算法分别提高了3.76％、6.46％和7.63％.；而将填充数据后的评分矩阵作为伪评分矩阵应用Pearson相关相似性进行协同过滤推荐则比传统的基于Pearson相关相似性的协同过滤推荐算法分别提高了6.57％、6.52％和7.60％.

关键词：个性化推荐系统协同过滤数据填充推荐策略

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Entanglement and decoherence of coupled superconductor qubits in a non-Markovian environment

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Chinese Physics B 2010年第6期19卷 46-51页

作者：嵇英华胡菊菊 College of Physics and Communication Electronics Jiangxi Normal University Key Laboratory of Optoelectronic and Telecommunication of Jiangxi School of Optical-Electrical Information and Computer Engineering University of Shanghai for Science and Technology

The sudden death of entanglement is investigated for the non-Markovian dynamic process of a pair of interacting flux qubits under a thermal bath. The results show that, for initially two-qubit entangled states, entanglement sudden death （ESD） always happens in the thermal reservoir, where its appearance strongly depends on the environment. In particular, ESD of the qubits occurs more easily for the non-Markovian process than for the Markovian one.

关键词： entanglement coupled qubits non-Markovian process concurrence

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Towards video management over relational database

Towards video management over relational database

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12th International Asia Pacific Web Conference, APWeb 2010

作者： Li, Hui Zhang, Xiao Wang, Shan Du, Xiaoyong School of Information Renmin University of China Key Laboratory of Data Engineering and Knowledge Engineering China

ISBN: (纸本)9780769540122

Video has become popular in our daily life for both professional and consumer applications. Both low level video processing and high level semantic video analysis are critically computational tasks in application domains. Most of current video computing tools are developed for specific analytic tasks, they are lack higher level interoperability with database and treat database merely as a relational data storage engine rather than an analytic platform, which causes inefficient data access and massive amount of data movement. In this paper, we study how to support video data management over relational database, and present our initial solutions of video data storage mechanism, video data access method and efficient video analytics. We also illustrate our ongoing prototype system HybVideo that developed in a novel architecture. It integrates above solutions to tackle the major challenges of providing a platform for both storage and analysis of video data. © 2010 IEEE.

关键词： information management

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Efficient Distributed Skyline Queries for Mobile Applications

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计算机科学技术学报（英文版） 2010年第3期25卷 523-536页

作者： Ying-Yuan Xiao Yue-Guo Chen Tianjin Key Laboratory of Intelligence Computing and Novel Software Technology Tianjin University of Technology Tianjin 300191China Key Laboratory of Computer Vision and System Tianjin University of TechnologyTianjin 300191China School of Computing National University of Singapore117417Singapore Key Laboratory of Data Engineering and Knowledge Engineering Renmin University of ChinaBeijing 100872China

In this paper,we consider skyline queries in a mobile and distributed environment,where data objects are distributed in some sites(database servers)which are interconnected through a high-speed wired network,and queries are issued by mobile units(laptop,cell phone,etc.)which access the data objects of database servers by wireless *** inherent properties of mobile computing environment such as mobility,limited wireless bandwidth,frequent disconnection,make skyline queries more *** show how to efficiently perform distributed skyline queries in a mobile environment and propose a skyline query processing approach,called efficient distributed skyline based on mobile computing(EDS-MC).In EDS-MC,a distributed skyline query is decomposed into five processing phases and each phase is elaborately designed in order to reduce the network communication,network delay and query response *** conduct extensive experiments in a simulated mobile database system,and the experimental results demonstrate the superiority of EDS-MC over other skyline query processing techniques on mobile computing.

关键词： skyline distributed query processing mobile database system

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A sampling-based algorithm for approximating maximum average value region in wireless sensor network

A sampling-based algorithm for approximating maximum average...

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International Workshop on Scheduling and Resource Management for Parallel and Distributed Systems

作者： Zhang, Hao Wu, Zhongbo Li, Deying Chen, Hong School of Information Renmin University of China Key Laboratory of Data Engineering and Knowledge Engineering MOE Beijing China

ISBN: (纸本)9780769541570

in wireless sensor network, sensory readings are often noisy due to the imprecision of measuring hardware and the disturbance of deployment environment, so it is often inaccurate if we use individual sensor readings to answer queries. In this paper, we consider a useful application of sensor network: maximum average value region query. This query returns the region with the maximum average value among all possible regions in the network, where the region is a fix-sized circle pre-defined by users. Using the average value of a region to answer the query, noises between sensors will be neutralized with each other, which will make the results more reliable. However, because of the huge amount of possible regions in the network, it is costly to process the query exactly. Therefore, w e propose a sampling-based algorithm AMAVR to deal with the problem approximately. AMAVR uses a background value to prun e the useless regions which cannot be the result. A further optimization strategy is also given to handle the situation that, background value based filter does not work when some individual sensor nodes have higher values than their neighbors. By using both of the two techniques, the scale of the sampling population can be effectively reduced, that is, we cost less energy to get a satisfying result. At last, the conducted simulations demonstrate the energy efficiency of the proposed methods in our paper. © 2010 IEEE.

关键词： Sensor nodes

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