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A novel method for traffic object detection based on improved approximated median filter

Journal of Information and Computational Science 2012年第8期9卷 2253-2261页

作者： Zhu, Jian Cao, Hongbing Liang, Qingwei Key Lab of Wireless Sensor Network and Communications Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences Shanghai 200050 China Wuxi Sensing Net Industrialization Research Institute Wuxi 214135 China

Aiming at the problems that when common algorithms are adopted to detect foreground objects in traffic surveillance videos, there are more false detection results with higher memory and time cost, an algorithm based on the approximated median filter is proposed for vehicle object detection under complex traffic scenes. The algorithm, which can suppress noise effectively without setting complicated parameters, takes full advantage of the information between adjacent video frames and sets up a dynamic model of the background updating rate to adjust the background updating rate adaptively in different regions of the background. It effectively decreases the complexity of computation and solves the problem of object ghost in the background caused by slow motion of the objects during the process of the background updating. The experimental results show that the proposed algorithm not only improves the accuracy of the foreground objects detection but also improves the real-time performance of the detection. © 2012 Binary Information Press.

关键词： Object detection

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NLOS Error Mitigation in Mobile Location Based on Modified Extended Kalman Filter

NLOS Error Mitigation in Mobile Location Based on Modified E...

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IEEE wireless communications and networking Conference (WCNC)

作者： Zhou, Xin Jin, A-Long Meng, Qingmin Key Lab. of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Southeast University Nanjing China National Mobile Communications Research Lab. Southeast University Nanjing China Nanjing University of Posts and Telecommunications Nanjing 210003 China

ISBN: (纸本)9781467304375;9781467304368

Geolocation and tracking of mobile objects is an important issue in wireless communication networks. Various methods have been devised and implemented to deal with such problems whose performance is particularly limited in non-line-of-sight propagation conditions. In this paper, we take advantage of the extended Kalman filter with some extensions, modifications and improvement of previous work to reduce the NLOS error in the location measurement. One of the key contributions of this paper is to present the methods that discriminate the NLOS measurements from the LOS measurements based on the standard deviation and K-means clustering and reconstruct the LOS measurements out of the NLOS measurements by polynomial fit in order to mitigate the NLOS error. Simulation results confirm the effectiveness and accuracy of our approach in comparison with the conventional EKF algorithm. Moreover, we do not model the distribution of the NLOS error due to its intractability.

关键词： Non-Line-of-Sight Extended Kalman filter K-means clustering LOS reconstruction polynomial fit

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Multi-sample clustering decision fusion for distributed target detection in wireless sensor networks

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Journal of China Universities of Posts and Telecommunications 2012年第SUPPL. 2期19卷 42-46+127页

作者： Chen, Lei Huang, Hai-Ping Wang, Ru-Chuan Qin, Xiao-Lin Wang, Qian-Yi College of Computer Nanjing University of Posts and Telecommunications Nanjing 210003 China Jiangsu High Technology Research Key Laboratory for Wireless Sensor Networks Nanjing 210003 China College of Computer Science and Technology Nanjing University of Aeronautics and Astronautics Nanjing 210016 China Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing University of Posts and Telecommunications Nanjing 210003 China

In this paper, we revisit the problem of target detection in wireless sensor networks (WSNs). Because that the practical environment of WSNs is very complex, and usually the target signal is mixed with a lot of random noises, the phenomenon impacts the performance of target detection experiment. This paper set forth a new way to improve the system performance. We introduce gather multiple sample when we get the observation signals. After obtaining the samples, we calculate the judgments of each sensor by fusion rule. At last local sensors transfer their judgments to the fusion center. We prove that the method is better than single sample through Monte Carlo experiments because of the full use of the observation signals. © 2012 The Journal of China Universities of Posts and Telecommunications.

关键词： wireless sensor networks

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Joint scheduling and power allocation in OFDMA network with decode-and-forward relaying

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2012 3rd International Conference on Information technology for Manufacturing Systems, ITMS 2012

作者： Lv, Linshu Zhu, Qi Key Wireless Lab of Jiangsu Province School of Telecommunication and Information Engineering Nanjing University of Posts and Telecommunications Nanjing China Key Lab on Wideband Wireless Communications and Sensor Network Technology Ministry of Education Nanjing China

ISBN: (纸本)9783037855317

This paper investigates the resource allocation of Orthogonal Frequency Division Multiplexing Access (OFDMA) cellular network with DF relaying in the downlink. A joint scheme of relay selection, subcarrier assignment and power allocation is proposed to maximize the system sum rate subject to individual power constraints and heterogeneous users' rate requirements. Since the original problem is a mixed integer programming (MIP), we transform it to a standard convex optimization by continuous relaxation and solve it via iterative water-filling (IWF) and subgradient methods in the dual domain. Beside the joint scheme, the upper bound is studied through an exhaustive bisection search. Simulations results show that the proposed scheme outperforms the traditional methods in terms of both system throughput and users' satisfactions. © (2012) Trans Tech Publications, Switzerland.

关键词： Orthogonal frequency division multiplexing

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Green networking Based Energy Efficient communications

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China communications 2012年第2期9卷 22-30页

作者： Wang Wennai Mi Zhengkun Wang Bin Key Lab of Broadband Wireless Communication and Sensor Network Technology(Nanjing University of Posts andTelecommunications) Nanjing 210003P.R.China

The mainstream approaches to green networking are discussed first from the view of engineering,including resource consolidation,server virtualization,selective connectedness,and proportional computing.A brief introduction to network virtualization techniques is given then and a virtual node embedding approach is ***,three kinds of enhanced green networking schemes by network virtualization are proposed,that is enhancement to sever virtualization,resource consolidation and Adaptive Link Rate(ALR).Examples are included to show the virtue of network virtualization to green networking in terms of energy efficient communications.

关键词： energy efficient communications greennetworking network virtualization green of Infor-mation and communications technology （ICT）

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Compressive Channel Sensing Based on Random Pilot for Physical Layer Communication Security

Compressive Channel Sensing Based on Random Pilot for Physic...

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2013 22nd wireless and Optical Communication Conference

作者： Hao Wei Baoyu Zheng Xiaoyun Hou Institute of Signal Processing and Transmission Nanjing University of Posts and Telecommunications National Mobile Communication Research Lab.Southeast University Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing University of Posts and Telecommunications

ISBN: (纸本)9781467356985

Accurate channel state information(CSI) is necessary for correctly receiving *** sensing has been used for channel estimation because of the sparsity of the wireless multipath *** on compressive sensing,the channel estimation performance by setting pilots randomly is much better than uniformly and *** paper proposed a scheme for security communication in physical layer by exploiting the randomness of pilots to prevent eavesdropping in wireless *** transmitter places the pilots according to the random pilot codebook,then the legitimate user can accurately estimate CSI according to the codebook and the eavesdropper cannot because of not knowing the position of *** simulation results show that the legitimate user can correctly decode information,while the BER performance of eavesdropper is very bad,and the security capacity is close to the legitimate user's *** scheme effectively ensures the safety of the physical layer communication.

关键词： physical layer security channel estimation compressive sensing random pilot

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Delay constraint adaptive routing based on seed spray in opportunistic networks

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Journal of Computational Information Systems 2012年第12期8卷 5137-5148页

作者： Xu, Jia Wang, Ruchuan Sun, Lijuan College of Computer Nanjing University of Posts and Telecommunications Nanjing 210003 China Jiangsu High Technology Research Key Laboratory for Wireless Sensor Networks Nanjing 210003 China Key Lab. of Broadband Wireless Communication and Sensor Network Technol. Min. of Edu. Jiangsu Prov. Nanjing University of Posts and Telecommunications Nanjing 210003 China Key Laboratory for Computer Network and Information Integration Ministry of Education Southeast University Nanjing 211189 China State Key Lab. for Novel Software Technology Nanjing University Nanjing 210093 China

Opportunistic networks are sparse wireless networks which have no complete path from the source to the destination most of the time. Many applications require the support of delay constrained routing mechanism which can provide acceptable and resilient services in the challenged environments. We proposed Adaptive Seed Spray (ASS) to achieve the delay constraint with low cost in dynamic opportunistic networks. ASS will estimate the routing cost in source node, and use a small number of seed nodes to spray message copies in order to reduce redundant copies. Furthermore, ASS will make spray decisions in relay nodes which have the latest information of the networking conditions. Simulation results have shown that ASS has prominent superiority in routing cost and adaptability, and it is an efficient delay-bounded multi-copy routing protocol for opportunistic networks especially for dynamic conditions. © 2012 Binary Information Press.

关键词： Cost benefit analysis

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A novel clustering mechanism based on image-oriented correlation coefficient for wireless multimedia sensor networks

A novel clustering mechanism based on image-oriented correla...

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2012 International Conference on Web Information Systems and Mining, WISM 2012

作者： Wu, Rong Wang, Ruchuan Sha, Chao Qian, Liyang College of Computer Nanjing University of Posts and Telecommunications Nanjing 210003 China Jiangsu High Technology Research Key Laboratory for Wireless Sensor Networks Nanjing 210003 China Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing University of Posts and Telecommunications Nanjing 210003 China

ISBN: (纸本)9783642334689

wireless multimedia sensor networks consist of unattended multimedia nodes with limited storage, energy and computation and communication capabilities. And energy is the most crucial resource for nodes. Clustering technique has been proven to be an effective approach for datagathering in wireless multimedia sensor networks. Therefore, this paper presents a novel clustering mechanism based on image-oriented correlation coefficient to reduce redundancy transmission so as to conserve network energy. And the aim is achieved through taking advantage of the correlation coefficient of captured images and RSSI value of nodes to avoid excessive computation and transmission. Moreover, a new cluster header election method is also presented to make the network's load balance on energy. The simulation results show that the correlation coefficient threshold greatly affects the number and average size of clusters. And compared with another clustering algorithm based on overlapping FoVs, our clustering mechanism is more effective in prolonging network lifetime. © Springer-Verlag Berlin Heidelberg 2012.

关键词： Clustering algorithms

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Gossip-based indexing ring topology for 2-dimension spatial data in overlay networks

Gossip-based indexing ring topology for 2-dimension spatial ...

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2012 International Workshop on Information and Electronics Engineering, IWIEE 2012

作者： Zou, Z.Q. Wang, Y. Hu, B. Wang, R.C. College of Computer Nanjing University of Posts and Telecommunications Nanjing Jiangsu 210003 China Jiangsu High Technology Research Key Laboratory for Wireless Sensor Networks Nanjing Jiangsu 210003 China Key Lab. of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Jiangsu Province Nanjing Jiangsu 210003 China

Overlay networks are used widely in the Internet, such as retrieval and share of files, multimedia games and so on. However, in distributed system, the retrieval and share of 2-dimension spatial data still have some difficult problems and can not solve the complex retrieval of 2-dimension spatial data efficiently. This article presents a new indexing overlay networks, named 2D-Ring, which is the ring topology based on gossip for 2-dimension spatial data. The peers in our overlay networks exchange the information periodically and update each local view by constructing algorithm. 2-dimension spatial data is divided by quad-tree and mapped into control points, which are hashed into 2D-Ring by SHA-1 hash function. In such way, the problem of 2-dimension spatial data indexing is converted to the problem of searching peers in the 2D-Ring. A large of extensive experiments show that the time complexity of constructing algorithm of 2D-Ring can reach convergence logarithmically as a function of the network size and hold higher hit rate and lower query delay. © 2011 Published by Elsevier Ltd.

关键词： Overlay networks

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Mean Shift Object Tracking with Modified LTP

Mean Shift Object Tracking with Modified LTP

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2012 IEEE 11th International Conference on Signal Processing(ICSP 2012)

作者： ZHANG Shaona HU Dong HU Yanting Education Ministry's Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications The key lab of image processing and transmission of Jiangsu province Nanjing University of Posts and Telecommunications School of Telecommunication and Information Engineering Nanjing University of Posts and Telecommunications

ISBN: (纸本)9781467321969

A new scheme of object tracking with mean shift is put forward in this paper. At first, texture feature is fused in the processing by Local Ternary Pattern (LTP). Since LTP is sensitive to local noise, least median of squares (LMedS) algorithm is used to adaptively calculate the noise threshold for accurate estimation of the LTP texture information. Furthermore, target scale and orientation is estimated in case of partial occlusion or rotation, so as to realize robust object tracking. Experimental results show that the proposed algorithm can acquire robust tracking performance under complex background .

关键词： Object tracking, Mean Shift, LTP, LMedS

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