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Huang J.,Beijing University of Posts and Telecommunications | Huang X.,Beijing University of Posts and Telecommunications | Ma Y.,Beijing University of Posts and Telecommunications | Ma Y.,Beijing Key Laboratory of Intelligent Telecommunications Software and Multimedia
Journal of Network and Computer Applications | Year: 2012

Finding a path that satisfies multiple Quality-of-Service (QoS) constraints is vital to the deployment of current emerged services. However, existing algorithms are not very efficient and effective at finding such a path. Moreover, few works focus on three or more QoS constraints. In this paper, we present an enhanced version of fully polynomial time approximation scheme (EFPTAS) for multiconstrainted path optimal (MCOP) problem. Specifically, we make four major contributions. We first allow the proposed algorithm to construct an auxiliary graph, through which the QoS parameters on each of the finding path can be guaranteed not to exceed the given constraints. Then we adopt a concept, called nonlinear definition of path constraints in EFPTAS for reducing both time and space complexity. Also, we enable EFPTAS to run iteratively to facilitate a progressive refinement of the finding result. In addition to these, we identify some deployment issues for proposed algorithm, the essential steps that how and when the EFPTAS takes place are presented. By analyzing the proposed algorithm theoretically, we find that the presented EFPTAS can find a (1ε)-approximation path in the network with time complexity O(|E||V|/ε) (where |E| is the number of edges and |V| is the number of nodes), which outperforms the previous best-known algorithm for MCOP. We conduct an extensive comparison between the algorithm presented in this paper and previous best-known study experimentally, our results indicate that EFPTAS can find a path with low complexity and preferable quality. © 2011 Elsevier Ltd. All rights reserved.


Mao X.,Beijing Key Laboratory of Intelligent Telecommunications Software and Multimedia | Xu X.,Illinois Institute of Technology | Tang S.,Illinois Institute of Technology | Li X.-Y.,Illinois Institute of Technology
Wireless Communications and Mobile Computing | Year: 2012

In this paper, we study k-road-coverage problems in wireless sensor networks (WSNs). Assume there is a 2-dimensional area ω with a given road map R=(V,E) where E contains all road segments and V consists of all intersection points on ω. The first question we study is about 'sensor deployment', i.e., how to deploy a minimum number of sensor nodes on ω such that each path (each road segment) on is k-covered when all sensor nodes have the same sensing range. When sensors can only be deployed in a set of discrete locations, we propose an efficient method with the approximation ratio 6 + ∈ for the special case where kR= 1 and O(k) generally. If sensors can be deployed in arbitrary locations, we propose an efficient method with the approximation ratio 24 + ∈ when kR= 1 and O(k) generally. The second question we study is about 'path query', i.e., how to find the k-covered path or k-support path connecting any given source/destination pair of points on the road map. Basically, given any source/destination pair of points S and D, we present two algorithms which can efficiently find a k-covered path connecting S and D and a k-supported path connecting S and D, respectively. Copyright © 2010 John Wiley & Sons, Ltd.


Yang Y.-H.,Xuchang University | Du J.-P.,Beijing University of Posts and Telecommunications | Du J.-P.,Beijing Key Laboratory of Intelligent Telecommunications Software and Multimedia | Ping Y.,Xuchang University
Ruan Jian Xue Bao/Journal of Software | Year: 2015

Recently, ontology-based intelligent information retrieval systems, aiming to further improve the retrieval performance and intelligence by using ontology, have become one of the hottest topics in the domain of intelligent information retrieval systems. This paper presents an overview of the field of ontology-based intelligent information retrieval systems from a process-oriented perspective, including the system framework, ontology knowledge acquisition and use, key technologies, and evaluation. The prospects for future development and suggestions for possible extensions of the ontology-based intelligent information retrieval systems are also discussed. © Copyright 2015, Institute of Software, the Chinese Academy of Sciences. All rights reserved.


Lan L.,Beijing University of Posts and Telecommunications | Wang B.,Beijing Key Laboratory of Intelligent Telecommunications Software and Multimedia | Zhang L.,Beijing Key Laboratory of Intelligent Telecommunications Software and Multimedia | Shi R.,Key Laboratory of Trustworthy Distributed Computing and Service Ministry of Education | Li F.,Vienna University of Technology
International Journal of Online Engineering | Year: 2015

IoT (Internet of Things) bridges the physical world and information space. IoT services are environmentally sensitive and event-driven, so new IoT service architecture should adapt to these features. This paper analyses IoT sensing service characteristics and proposes future services architecture. It is focused on middleware architecture and interface presentation technology. In the middleware layer, traditional SOA architecture is insufficient in real-time response and parallel processes of service execution. This paper proposes a new sensing service system based on EDSOA (Event Driven SOA) architecture to support realtime, event-driven, and active service execution. At the presentation layer, this paper presents new IoT browser features, including using augmented reality technology for input and output and realizing the superposition of the physical world and abstract information. Through a use case and proof-of-concept implementation-road manhole cover monitoring system-we verified the feasibility of the proposed ideas and framework.


Mao X.,Beijing Key Laboratory of Intelligent Telecommunications Software and Multimedia | Tang S.,Illinois Institute of Technology | Xu X.,Illinois Institute of Technology | Li X.-Y.,Illinois Institute of Technology | Ma H.,Beijing Key Laboratory of Intelligent Telecommunications Software and Multimedia
Proceedings - IEEE INFOCOM | Year: 2011

Target tracking is a main application of wireless sensor networks (WSNs), and has been studied widely [4], [10]. In this work, we study indoor passive tracking problem using WSNs, in which we assume no equipment is carried by the target and the tracking procedure is passive. We propose to use light to track a moving target in WSNs. To our best knowledge, this is the first work which tracks a moving object by using light sensors and general light sources. We design a novel probabilistic protocol (system) iLight to track a moving target and several efficient methods to compute the target's moving patterns (like height, etc.) at the same time. We implement and evaluate our tracking system iLight in a testbed consisting of 40 sensor nodes, 10 general light sources and one base station. Through extensive experiments, we show that iLight can track a moving target efficiently and accurately. © 2011 IEEE.

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