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Compressive Wideband Spectrum Sensing Based on Random Matrix Theory

Journal of Donghua University(English Edition) 2015年第2期32卷 248-251页

作者：曹开田戴林燕杭燚灵张蕾顾凯冬 Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of EducationNanjing University of Posts and Telecommunications College of Overseas Education Nanjing University of Posts and Telecommunications

Spectrum sensing in a wideband regime for cognitive radio network(CRN) faces considerably technical challenge due to the constraints on analog-to-digital converters(ADCs).To solve this problem,an eigenvalue-based compressive wideband spectrum sensing(ECWSS) scheme using random matrix theory(RMT) was proposed in this *** ECWSS directly utilized the compressive measurements based on compressive sampling(CS) theory to perform wideband spectrum sensing without requiring signal recovery,which could greatly reduce computational complexity and data acquisition *** the ECWSS,to alleviate the communication overhead of secondary user(SU),the sensors around SU carried out compressive sampling at the sub-Nyquist rate instead of ***,the exact probability density function of extreme eigenvalues was used to set the *** analyses and simulation results show that compared with the existing eigenvalue-based sensing schemes,the ECWSS has much lower computational complexity and cost with no significant detection performance degradation.

关键词： compressive wideband Spectrum overhead exact eigenvalue utilized instead considerably constraints

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Online video synopsis method through simple tube projection strategy

Online video synopsis method through simple tube projection ...

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International Conference on Wireless communications and Signal Processing (WCSP)

作者： Jing Jin Feng Liu Zongliang Gan Ziguan Cui Jiangsu Province Key Lab on Image Processing & Image Communications Nanjing University of Posts and Telecommunications Nanjing China Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing University of Posts and Telecommunications Nanjing China

ISBN: (纸本)9781509028610

Traditional video synopsis methods model the processing into an optimization formula where relations among objects such as collision cost are utilized while entire re-calculation is introduced under each possible temporal shift. Unlike the pairwise cost optimization, we propose a low-complexity and efficient online synopsis method where each tube is processed independently. Without tubes' comparison, the rearrangement is accomplished by a simple projection strategy and an updating projection matrix which records the newest information of the moving space. Furthermore, buffer and a predefined fitness condition also help to increase spatial and temporal utilization. Experiment results demonstrate that the proposed method is superior to other synopsis methods in the processing speed and temporal consistency.

关键词： Streaming media Electron tubes Trajectory Optimization Surveillance Telecommunications Cameras

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A Novel Two-Stage PCA Algorithm for Object Tracking

A Novel Two-Stage PCA Algorithm for Object Tracking

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2016 International Conference on communications, Information Management and network Security (CIMNS2016)

作者： Yuanyuan Yang Dong Hu Education Ministry's Key Lab of Broadband Wireless Communication and Sensor Network Technology Education Ministry's Engineering Research Center of Ubiquitous Network and Heath Service Jiangsu Province's Key Lab of Image Procession and Image Communications Nanjing University of Posts and Telecommunications

ISBN: (纸本)9781510830981

In this paper, we propose a two-stage PCA algorithm to deal with the problem of target appearance changes in object tracking. Our method is based on particle filter framework and aims at building up a robust appearance model for the target. In the first-stage, PCA is applied on several templates collected before tracking to construct a low dimensional subspace for the targets. Correspondingly, in the later tracking, all particles will be projected into this subspace to calculate the weight of particles, as well as the location of the target by weighted sum of particles. In the second-stage, PCA is adopted to decompose the reconstruction error into orthogonal basis to find the basis with biggest variance which can best present the appearance changes. Correspondingly, we uses this basis to update the old subspace. Besides, a threshold is set to decide when to update which greatly reduce the numbers of update. The two stages work together to establish a robust appearance model making our tracking algorithm more robust. Experimental results on public video sequence demonstrate the effectiveness of our proposed algorithm.

关键词： particle filter two-stage PCA eigenspace reconstruction error

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Effective Scheme for Global Abnormal Event Detection for Surveillance Video

Effective Scheme for Global Abnormal Event Detection for Sur...

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2016 International Conference on communications, Information Management and network Security (CIMNS2016)

作者： Fangxu Dong Dong Hu Education Ministry's Key Lab of Broadband Wireless Communication and Sensor Network Technology Education Ministry's Engineering Research Center of Ubiquitous Network and Heath Service Jiangsu Province's Key Lab of Image Processing and Image Communications Nanjing University of Posts and Telecommunications

ISBN: (纸本)9781510830981

An effective algorithm for global abnormal detection from surveillance video is proposed in this paper. The algorithm is based on sparse representation. To deal with the illumination change in video scenes, specific feature extract methods are designed for corresponding illumination conditions. In the case of non-uniform illumination, features are extracted directly on the original image;in the case of uniform illumination, features are extracted on the binary image obtained by threshold segmentation on the difference image, where the thresholds are computed by the Otsu's method. The features extracted on normal video are used to learn an over-complete dictionary. Then, the sparse reconstruction cost over the dictionary is used to detect abnormal events. Experiments on the open global abnormal dataset and the comparison to the state-of-the-art methods validate effectiveness and quickness of our algorithm.

关键词： abnormal detection illumination change binary images sparse reconstruction cost

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A novel saliency detection model based on curvelet transform

A novel saliency detection model based on curvelet transform

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International Conference on Wireless communications and Signal Processing (WCSP)

作者： Peiqing Bai Ziguan Cui Zongliang Gan Guijin Tang Feng Liu Image Processing & Image Communication Lab Nanjing University of Posts & Telecommunications Nanjing China Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing University of Posts & Telecommunications Nanjing China State Key Laboratory for Novel Software Technology Nanjing University Nanjing China

ISBN: (纸本)9781509028610

Visually salient object or region detection in images is an active research field in recent years. Inspired by that curvelets can provide multi-scale sparse representation of objects with edges and textures, in this paper, we propose a novel saliency detection model based on fast discrete curvelet transform (SDCT) to detect more compact salient objects in an image. First, fast discrete curvelet transform is used to acquire multi-scale representation of feature maps in CIElab color space. Then the feature maps are transformed to feature salient maps based on dissimilarity measure between patches in a global manner. Finally, the complementary feature salient maps at each scale and each color channel are merged linearly to obtain unitary saliency map. Experimental results on MSRA saliency benchmark database show that the proposed SDCT model outperforms the most state-of-the-art saliency detection models in spatial and frequency domain with higher overall performance, especially acquires more compact salient object and suppresses background saliency effectively, which is desirable for many computer vision applications.

关键词： Transforms Feature extraction Image color analysis Frequency-domain analysis Computational modeling Visualization Image edge detection

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Blind spot coverage strategy based on D2D communications for electric LTE network

Blind spot coverage strategy based on D2D communications for...

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International Conference on Wireless communications and Signal Processing (WCSP)

作者： Jiming Yao Tao Wang Xiao Wu Lei Wang Baoyu Zheng Global Energy Interconnection Research institute Nanjing China National Mobile Communications Research Laboratory Southeast University Nanjing China Key Lab of Broadband Wireless Communication and Sensor Network Technology (NUPT) Nanjing China

ISBN: (纸本)9781509028610

With the development of smart of grid, the traditional wireless communication cannot meet the new service requirement. In this paper, we propose a blind spots coverage based on D2D communication scheme to solve the problems of blind spots coverage and service access imbalance for power LTE private network. Meanwhile, we analyze the application of D2D communication technology based on LTE in power grid. In addition, we introduce the type of power LTE private network, discuss the mode of D2D communication in different scenarios between intra-frequency network and differ-frequency network, and explore the typical application scenarios of D2D technology in power grid. We also find that there still remains several open issues in application of D2D technology for the electric power industry.

关键词： Device-to-device communication Long Term Evolution Base stations Power systems Wireless communication Bandwidth Cellular networks

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An improved flooding protocol based on network coding

An improved flooding protocol based on network coding

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International Conference on Information technology and Computer Application Engineering, ITCAE 2014

作者： Zhang, Li Na Zhang, Deng Yin Ji, Ying Tian Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Ministry of Education Nanjing China

ISBN: (纸本)9781138027176

network coding allows network node to process data by the traditional method of data forwarding, which can effectively improve network throughput, robustness and reliability. In this paper, we propose an improved flooding protocol NCFD (network coding of flooding), which combines network coding technology with flooding protocol, adopting linear network coding technology based on multipath propagation. Computer simulation results show that NCFD could significantly reduce network energy consumption and data redundancy. © 2015 Taylor & Francis Group, London.

关键词： network coding

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A hybrid image registering algorithm of improved Powell algorithm and simulated annealing algorithm 4th

A hybrid image registering algorithm of improved Powell algo...

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4th International Conference on Electronics, communications and networks, CECNet2014

作者： Ji, Yingtian Zhang, Dengyin Tan, Lipin Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Ministry of Education NanjingJiangsu China

ISBN: (纸本)9781138028302

With the development of computer technology and Biomedical Engineering, the image registering technology is widely used in healthcare and the disease diagnosis and clinical care demand higher registering precision and speed. In this paper, against the defect that the Powell method is prone to obtain a local extremum, we propose an improved Powellalgorithm which can improve the registering precision and robustness with the simulated annealing algorithm in a multi-resolution strategy. The experiment demonstrates our method is an effective way to reduce the registering error. © 2015 Taylor & Francis Group, London.

关键词： Simulated annealing

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Invisible cloak fails: CSI-based passive human detection 1

Invisible cloak fails: CSI-based passive human detection

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1st ACM Workshop on Context Sensing and Activity Recognition, CSAR 2015

作者： Xiao, Fu Xie, Xiaohui Zhu, Hai Sun, Lijuan Wang, Ruchuan School of Computer Nanjing University of Posts and Telecommunications China Jiangsu High Technology Research Key Laboratory for Wireless Sensor Networks China Key Lab of Broadband Wireless Communication and Sensor Network Technology China

ISBN: (纸本)9781450338424

WiFi signals have attracted extensive attention for context-aware due to its ubiquity. Traditional WiFi sensing methods mainly adopt Received Signal Strength Indication (RSSI), however the coarse features hamper its expansion. To achieve more finger-grained information, Channel State Information (CSI) is introduced for sensing, based on which, we design a directional human detection scheme via data prediction, which aims to visualize the variations of CSI when human appears. However, this scheme suffers from the limitations caused by the link-centric architecture of WiFi. Considering the demands for omnidirectional coverage of some scenarios (e.g. museum exhibition), we propose a omni-directional detection scheme based on fingerprinting utilizing the relationship between the CSI signal features and locations. Experiments are processed in actual scenarios and experimental results verify the feasibility of our two schemes. © 2015 ACM.

关键词： Channel state information

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The hybrid encryption algorithm of lightweight data in cloud storage

The hybrid encryption algorithm of lightweight data in cloud...

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International Symposium on Agents, Multi-Agent Systems and Robotics (ISAMSR)

作者： Chengliang Liang Ning Ye Reza Malekian Ruchuan Wang College of Computer Nanjing University of Posts and Telecommunications Nanjing China Jiangsu High Technology Research Key Laboratory for Wireless Sensor Networks Nanjing China Department of Electrical Electronic and Computer Engineering University of Pretoria Pretoria South Africa Key Lab of Broadband Wireless Communication and Sensor Network Nanjing University of Post and Telecommunications Nanjing China

In this paper, we proposed a hybrid encryption algorithm in order to solve the security problems on lightweight data on the cloud storage service. This paper first improves the RSA algorithm in the cloud environment by increasing the length of the RSA key to an extent that it can quickly generate big primes. Then, we merge AES and RSA algorithms on the basis of the improved RSA algorithm. This is called a hybrid encryption algorithm which is suitable for security of the lightweight data in cloud storage environment in order to further enhance the confidentiality of data in the cloud. The experimental result shows that the hybrid encryption algorithm has advantages of fast encryption and decryption, more secure, and it is also able to settle the security problems of users' lightweight data in a certain extent.

关键词： Encryption Cloud computing Algorithm design and analysis Public key Access control

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