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Energy Efficient Multicast Routing for Discrete Power Levels in Ad Hoc Sensor Networks

Energy Efficient Multicast Routing for Discrete Power Levels...

The 4th International Conference on Wireless Communications, Networking and Mobile Computing(第四届IEEE无线通信、网络技术及移动计算国际会议)

作者： Deying Li Qinghua Zhu Zheng Li Key Laboratory of Data Engineering and Knowledge Engineering (Renmin University of China) MOE Scho School of Information Renmin University of China Beijing 100872 P.R.China

In this paper, we discuss the energy efficient multicast problem for discrete power levels in ad hoc sensor wireless networks. The problem of our concern is: given n nodes and each node v has l(v) transmission power levels and a multicast request (s, D), how to find a multicast tree rooted at s and spanning all destinations in D such that the total energy cost of the multicast tree is minimized. This problem is NP-hard. We propose a NWM_DST algorithm which has a theoretical guaranteed approximation performance ratio, and two efficient heuristics MNJT and g-D-MIP for multicast tree problem. Simulation results have shown efficiency of our proposed algorithms.

关键词： wireless sensor network energy efficiency approzimation algorithm multicast routing

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An Edit Distance Algorithm with Block Swap

An Edit Distance Algorithm with Block Swap

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The 9th International Conference for Young Computer Scientists(第九届国际青年计算机大会)

作者： Tian Xia Key Laboratory of Data Engineering and Knowledge Engineering Renmin University of China MOE Beijing 100872 China School of Information Resource Management Renmin University of China. Beijing 100872 China

The edit distance between two given strings X and Y is the minimum number of edit operations that transform X into Y. In ordinary course, string editing is based on character insert, delete, and substitute operations. It has been suggested that extending this model with block edits would be useful in applications such as DNA sequence comparison and sentence similarity computation. However, the existing algorithms have generally focused on the normalized edit distance, and seldom of them consider the block swap operations at a higher level. In this paper, we introduce an extended edit distance algorithm which permits insertions, deletions, and substitutions at character level, and also permits block swap operations. Experimental results on randomly generated strings verify the algorithm's rationality and efficiency. The main contribution of this paper is that we present an algorithm to compute the lowest edit cost for string transformation with block swap in polynomial time, and propose a breaking points selection algorithm to improve the computation speed.

关键词： Edit distance edit operation block swap string matching.

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Automatic detection of integer sign vulnerabilities

Automatic detection of integer sign vulnerabilities

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International Conference on Information and Automation (ICIA)

作者： Bin Liang Hui Liu Wenchang Shi Zhiyong Shan Renmin University of China Beijing CN College of Computer Science and Technology Huazhong University of Science and Technology Wuhan China Key Laboratory of Data Engineering and Knowledge Engineering (Renmin University of China) MOE Beijing 100872 China

The integer sign vulnerability is a comparatively new and subtle type of vulnerabilities, they can compromise system security. Especially, if a sign vulnerability occurs in operating system kernel, it may result in very serious invalid read/write operations to kernel memory area. Unfortunately, little attention has been paid to static detecting them automatically. This paper presents a novel approach to detecting sign vulnerabilities in Linux kernel using type qualifier technique. We introduce three pairs of type qualifier and corresponding lattices to identify some key kernel data and relationships between them. Based on an extended type inference tool, we are able to effectively detect known and unknown sign vulnerabilities from elaborately preprocessed Linux kernel files. Our experiences demonstrate that type qualifier technique can be applied to detect sign vulnerabilities effectively.

关键词： Kernel Linux Lattices Indexes Arrays Security Buffer overflow

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MRST-- An Efficient Monitoring Technology of Summarization on Stream data

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Journal of Computer Science & Technology 2007年第2期22卷 190-196页

作者：樊小泊解婷婷李翠平陈红 School of Information Renmin University of China Beijing 100872 China Key Laboratory of Data Engineering and Knowledge Engineering MOE Beijing 100872 China

Monitoring on data streams is an efficient method of acquiring the characters of data stream. However the available resources for each data stream are limited, so the problem of how to use the limited resources to process infinite data stream is an open challenging problem. In this paper, we adopt the wavelet and sliding window methods to design a multi-resolution summarization data structure, the Multi-Resolution Summarization Tree （MRST） which can be updated incrementally with the incoming data and can support point queries, range queries, multi-point queries and keep the precision of queries. We use both synthetic data and real-world data to evaluate our algorithm. The results of experiment indicate that the efficiency of query and the adaptability of MRST have exceeded the current algorithm, at the same time the realization of it is simpler than others.

关键词： Haar wavelet sliding window stream data

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A WSMO-based semantic web services discovery framework in heterogeneous ontologies environment

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2nd International Conference on knowledge Science, engineering and Management, KSEM 2007

作者： Haihua, Li Xiaoyong, Du Xuan, Tian School of Information Renmin University of China China Key Laboratory of Data Engineering and Knowledge Engineering MOE

ISBN: (纸本)9783540767183

Nowadays, WSMO (Web Service Modeling Ontology)1 has received great attention of academic and business communities, since its potential to achieve dynamic and scalable infrastructure for web services is extracted. Therefore, we design an ontology-based Semantic Web Services (SWSs) discovery framework based on WSMO so as to searching dynamically web services located at different nodes. Also, we provide several SWSs matching techniques based on this framework. © Springer-Verlag Berlin Heidelberg 2007.

关键词： Semantic Web

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Optimization framework for distributed clustering scheme in wireless sensor networks

Optimization framework for distributed clustering scheme in ...

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SNPD 2007: 8th ACIS International Conference on Software engineering, Artificial Intelligence, Networking, and Parallel/Distributed Computing

作者： Yongxuan, Lai Xiaobo, Fan Hong, Chen Tingting, Xie School of Information Renmin University of China Beijing Key Laboratory of Data Engineering and Knowledge Engineering MOE

ISBN: (纸本)0769529097

Recently there have been growing interests in the applications of wireless sensor networks. Innovative techniques that improve energy efficiency to prolong the network lifetime are highly required. Clustering is an effective topology control approach and data gathering protocol in wireless sensor networks. In this paper, we propose a novel optimization framework called MICA (MICa Adjustments) for clustering scheme in wireless sensor networks. MICA takes the cluster as a whole, and dynamically adjusts the clusters according to the real-lime workload of the local clusters to balance energy consumption among clusters. The adjustments can also deal with link failures. Simulation results show that MICA can be easily embedded into existing clustering schemes to balance the energy consumptions among the clusters, and to prolong the lifetime of wireless sensor networks. © 2007 IEEE.

关键词： Wireless sensor networks

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Effective density queries for moving objects in road networks

Effective density queries for moving objects in road network...

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9th Asia-Pacific Web Conference/8th International Conference on Web-Age Information Management (APWeb/WAIM 2007)

作者： Lai, Caifeng Wang, Ling Chen, Jidong Meng, Xiaofeng Zeitouni, Karine School of Information Renmin University of China Key Laboratory of Data Engineering and Knowledge Engineering MOE PRISM Versailles Saint-Quentin University France

ISBN: (纸本)9783540724834

Recent research has focused on density queries for moving objects in highly dynamic scenarios. An area is dense if the number of moving objects it contains is above some threshold. Monitoring dense areas has applications in traffic control systems, bandwidth management, collision probability evaluation, etc. All existing methods, however, assume the objects moving in the Euclidean space. In this paper, we study the density queries in road networks, where density computation is determined by the length of the road segment and the number of objects on it. We define an effective road-network density query guaranteeing to obtain useful answers. We then propose the cluster-based algorithm for the efficient computation of density queries for objects moving in road networks. Extensive experimental results show that our methods achieve high efficiency and accuracy for finding the dense areas in road networks. © Springer-Verlag Berlin Heidelberg 2007.

关键词： Object recognition

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Clustering moving objects in spatial networks

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12th International Conference on database Systems for Advanced Applications

作者： Chen, Jidong Lai, Caifeng Meng, Xiaofeng Xu, Jianliang Hu, Haibo School of Information Renmin University of China Key Laboratory of Data Engineering and Knowledge Engineering MOE Department of Computer Science Hong Kong Baptist University

ISBN: (纸本)9783540717027

Advances in wireless networks and positioning technologies (e.g., CPS) have enabled new data management applications that monitor moving objects. In such new applications, realtime data analysis such as clustering analysis is becoming one of the most important requirements. In this paper, we present the problem of clustering moving objects in spatial networks and propose a unified framework to address this problem. Due to the innate feature of continuously changing positions of moving objects, the clustering results dynamically change. By exploiting the unique features of road networks, our framework first introduces a notion of cluster block (CB) as the underlying clustering unit. We then divide the clustering process into the continuous maintenance of CBs and periodical construction of clusters with different criteria based on CBs. The algorithms for efficiently maintaining and organizing the CBs to construct clusters are proposed. Extensive experimental results show that our clustering framework achieves high efficiency for clustering moving objects in real road networks.

关键词： spatial-temporal databases moving objects clustering spatial networks

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Building bilingual ontology from WordNet and Chinese classified thesaurus

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2nd International Conference on knowledge Science, engineering and Management, KSEM 2007

作者： He, Hu Xiaoyong, Du School of Information Renmin University of China 100872 Beijing China Key Lab. of Data and Knowledge Engineering MOE 100872 Beijing China

ISBN: (纸本)9783540767183

Both WordNet and Chinese Classified Thesaurus(CCT) are widely used in information retrieval and management systems. In this paper we propose a novel approach for building bilingual ontologies based on these existing knowledge bases, WordNet and CCT. The bilingual ontology has the merit that contains both domain related and general purpose semantic information coverage from these two complementary knowledge sources. A lattice based similarity measure and assessment algorithm is used for aligning and merging these two knowledge bases. © Springer-Verlag Berlin Heidelberg 2007.

关键词： Ontology

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Ontology hierarchies matching by lattices alignment

Ontology hierarchies matching by lattices alignment

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2nd International Workshop on Ontology Matching, OM-2007 - Collocated with the 6th International Semantic Web Conference, ISWC-2007 and the 2nd Asian Semantic Web Conference, ASWC-2007

作者： He, Hu Du, Xiaoyong School of Information Renmin University of China 100872 Beijing China Key Lab. of Data and Knowledge Engineering MOE 100872 Beijing China

Ontology matching determines the correspondences between concepts and relations of related ontologies. In this paper, we put forward an ontology hierarchies matching approach based on lattices alignment. The proposed lattice-based matching algorithm can be utilized not only in matching processes between two ontologies, but also in annotation processes between an ontology and its corresponding resources. Experiments on spatiotemporal ontology annotation have been carried out which shown the applicability of the approach.

关键词： Ontology

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