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arXiv 2017年

作者： Xiong, Siqing Wang, Lijun Kwak, Kyung Sup Bai, Zhiquan Wang, Jiang Li, Qiang Han, Tao School of Electronic Information and Communications Huazhong University of Science and Technology Wuhan China School of Electronic Information Wuhan University Wuhan China Faculty of information science and technology Wenhua College Wuhan China Department of Information and Communication Inha university Incheon Korea Republic of School of Information Science and Engineering Shandong University Jinan China Shanghai Research Center for Wireless Communications Shanghai China Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences Shanghai China Key lab of wireless sensor network and communication Chinese Academy of Sciences Shanghai China

—Based on the distinguishing features of multi-tier millimeter wave (mmWave) networks such as different transmit powers, different directivity gains from directional beamforming alignment and path loss laws for line-of-sight (LOS) and non-line-of-sight (NLOS) links, we introduce a normalization model to simplify the analysis of multi-tier mmWave cellular networks. The highlight of the model is that we convert a multi-tier mmWave cellular network into a single-tier mmWave network, where all the base stations (BSs) have the same normalized transmit power 1 and the densities of BSs scaled by LOS or NLOS scaling factors respectively follow piecewise constant function which has multiple demarcation points. On this basis, expressions for computing the coverage probability are obtained in general case with beamforming alignment errors and the special case with perfect beamforming alignment in the communication. According to corresponding numerical exploration, we conclude that the normalization model for multi-tier mmWave cellular networks fully meets requirements of network performance analysis, and it is simpler and clearer than the untransformed model. Besides, an unexpected but sensible finding is that there is an optimal beam width that maximizes coverage probability in the case with beamforming alignment errors. Copyright © 2017, The Authors. All rights reserved.

关键词： wireless networks

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Capacity-Based Channel Assignment Scheme in Multi-radio Multi-channel wireless Mesh networks

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Chinese Journal of Electronics 2015年第2期24卷 419-425页

作者： LI Yangfan WU Peng LIU Xinhua School of Automation Huazhong University of Science and Technology School of Information Engineering Wuhan University of Technology Key Lab. of Broadband Wireless Communications and Sensor Networks Wuhan University of Technology

The capacity of wireless mesh networks can be greatly enhanced by equipping each mesh router with multiple radios and by exploiting multiple channels to reduce network interference. It has been proved that an efficient channel assignment scheme is critical to achieve the optimal network throughput. This paper presents a centralized channel assignment scheme for multi-radio multichannel wireless mesh networks. The scheme includes a spanner-based topology control operation and a linkranking channel assignment algorithm. In the topology control procedure, several links that cause intense interference are removed from the network without damage to the basic network connectivity. The channel assignment procedure improves the network throughput via ranking links based on the principle of load balance. The simulation results demonstrate that the proposed scheme outperforms the compared centralized channel assignment approach in terms of network throughput. The experimental results also indicate that the effectiveness of the proposed scheme is even evident in the case of heavy input traffic load where the potential interference in the network is severe.

关键词： wireless mesh networks Channel assignment Topology control Ranking link

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T-QoS-aware based parallel ant colony algorithm for services composition

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Journal of Systems Engineering and Electronics 2015年第5期26卷 1100-1106页

作者： Lin Zhang Kaili Rao Ruchuan Wang College of Computer Nanjing University of Posts and Telecommunications Institute of Computer Technology Nanjing University of Posts and Telecommunications Jiangsu High Technology Research Key Laboratory for Wireless Sensor Networks Key Lab of Broadband Wireless Communication and Sensor Network Technology Nangjing University of Posts and Telecommunications

In order to make cloud users get credible, high-quality composition of services, the trust quality of service aware(TQoS-aware) based parallel ant colony algorithm is proposed. Our approach takes the service credibility as the weight of the quality of service, then calculates the trust service quality T-QoS for each service, making the service composition situated in a credible environment. Through the establishment on a per-service T-QoS initialization pheromone matrix, we can reduce the colony’s initial search time. By modifying the pheromone updating rules and introducing two ant colonies to search from different angles in parallel,we can avoid falling into the local optimal solution, and quickly find the optimal combination of global solutions. Experiments show that our approach can combine high-quality services and the improvement of the operational success rate. Also, the convergence rate and the accuracy of optimal combination are improved.

关键词： services composition trust service quality ant colony algorithm parallel

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Evaluation for IPTV service based on poor-quality model

Evaluation for IPTV service based on poor-quality model

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International Symposium on wireless Personal Multimedia communications (WPMC)

作者： Rui Li Zhifeng Wu Ruochen Huang Xin Wei Yi Qian ZTE CORPORATION China Key Lab of Broadband Wireless Communication and Sensor Network Technology (Nanjing University of Posts and Telecommunications) Ministry of Education China

ISBN: (纸本)9781509053773

This paper proposes an integrated poor-quality model to find the potential relationship between elected STB (set-top boxes) indicators and network conditions. The target is to make the IPTV network fault diagnosis more accurately and efficiently, especially for the sudden pause or blurred screen. The integrated poor-quality model consists of indicator, record and user model. Firstly, the poor-quality indicator model is in charge of selecting the effective indexes from candidate STB indicators. From the result of experiment, we conclude that jitter, abend-number and MLR (media loss rate) are the most important QoS (Quality of Service) parameters in our scenario. Secondly, the poor-quality record model has responsibility for adjustment of threshold values in order to meet the needs of higher accuracy rate with lower misjudgment ratio. Finally, the poor-quality user model takes customer's viewing time parameter into account, which can reflect end user's quality of experience objectively.

关键词： IPTV Quality of service Correlation Jitter Indexes Multimedia communication

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International Conference on wireless communications and Signal Processing (WCSP)

作者： Lihua Gao Haitao Ling Xutong Fan Jianxin Chen Qin Yin Lei Wang China Telecom Co Jiangsu Branch. Key Lab of Broadband Wireless Communication and Sensor Network Technology University of Telecommunications Ministry of Education Nanjing Multimedia Service Product Dept. China Telecom Co Jiangsu Branch Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Telecommunications Ministry of Education

ISBN: (纸本)9781509028610

With the popularity of network, P2P-based Video on Demand (VoD) has become one of the main services in Internet. However, due to the huge amount of videos, how to access the video quickly is important since it affects the subscriber's experience. In this paper, a popularity-driven storing model is proposed to fasten the video discovery for a centralized P2P-VoD system. All videos are stored in a binary tree in the server according to their popularities. Experimental results show that this scheme works well in terms of discovery delay and resource utilization.

关键词： Binary trees Servers Delays Peer-to-peer computing Telecommunications Computational modeling wireless communication

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TA3C: Teaching-Oriented Adaptive Wi-Fi Authorized Access Control Based on CSI

TA3C: Teaching-Oriented Adaptive Wi-Fi Authorized Access Con...

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International Conference on Mobile Ad-hoc and sensor networks, MSN

作者： Fu Xiao Jing Chen Xiaohui Xie Lijuan Sun Ruchuan Wang Key Lab of Broadband Wireless Communication and Sensor Network Technology of Ministry of Education Jiangsu China College of Computer Nanjing University of Posts and Telecommunications Jiangsu China

ISBN: (纸本)9781509056972

Wi-Fi has been widely deployed with the rapid development of wireless communication technique. Wi-Fi hotspots are popular in campus, making convenient wireless network access possible. However, during class teaching, in order to avoid students browsing the web based on Wi-Fi hotspots and distracting, we hope Wi-Fi hotspots adaptively shield network access to students in the classroom, while grant access to users outside the classroom. In this work, we prototype TA3C system, a teaching-oriented adaptive Wi-Fi authorized access control scheme, using Channel State Information (CSI) to locate instead of coarse-grained and temporally unstable Received Signal Strength Indication (RSSI). CSI can distinguish multipath signals, stay stable in the same propagation environment, and show different characteristics in different propagation environments, based on which, we can distinguish outdoor and indoor environments, and identify user's location to decide whether to offer him wireless network access or not. Experiment results show that TA3C effectively achieve adaptive Wi-Fi authorized access control, which provides a guarantee for the quality of class teaching. Compared to traditional indoor localization techniques, TA3C does not need accurate location information but simply recognizes user's location indoors or outdoors, which means it does not need dedicated hardware, realizing the low-cost indoor localization technique.

关键词： wireless communication wireless fidelity wireless sensor networks Antennas Fingerprint recognition Correlation coefficient Correlation

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Enhancement of color image based on tone-preserving

Enhancement of color image based on tone-preserving

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International Conference on wireless communications and Signal Processing (WCSP)

作者： Ya'nan Yang Xiaofan Wang Feng Liu Zongliang Gan 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

Since the lighting conditions in strong contrast regions between the light and dark cant be estimated accurately by traditional center/surround Retinex algorithm, the over-enhancement and color distortion may exist. In view of this, combining with the human visual characteristics, a color image enhancement algorithm based on tone-preserving was proposed. A determination function was added to the bilateral filter to estimate illuminance image more accurately and weaken over-enhancement. According to human visual masking effect, the improved gamma correction was utilized to correct the brightness of illumination image adaptively and the local contrast of reflection image obtained by division was enhanced based on local statistics. Besides, the final enhanced image was obtained by combining illumination image with reflection image, which can make image appear more natural. Compared with other similar algorithms from both subjective and objective aspects, the results show that this method being applied to low-contrast color image enhancement can not only improve image clarity, but reduce color distortion.

关键词： Image color analysis Brightness Lighting Color Visualization Nonlinear distortion

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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 New BDI Forecasting Model based on Support Vector Machine

A New BDI Forecasting Model based on Support Vector Machine

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2016 IEEE Information technology,networking,Electronic and Automation Control Conference(ITNEC 2016)

作者： Jianmin Bao Lin Pan Yuanfa Xie Key Lab of Broadband Wireless Communication and Sensor Network Technology (Jiangsu Provincial Engineering Research Center of Telecommunications and Network Technology) Ministry of Education Baer Institute of Excellence Nanjing University of Posts and Telecommunications

ISBN: (纸本)9781467391955

BDI(Dry Baltic Index) is a barometer of the shipping market, which is very important and difficult to predict precisely. The traditional forecasting method is not enough to predict precisely for it with higher complexity. The support vector machine has strong nonlinear function approximation and strong generalization ability. In this paper, a new BDI forecasting model based on support vector machine combined with CFS(Correlation-based Feature Selection) is presented and we first introduce the macroeconomic fundamental indicators of BDI. Firstly, we studied and researched the main macroeconomic fundamental indicators of BDI, investigate the inherent law and external influence of freight index fluctuation, and then put forward the BDI forecasting model based on support vector machine and demonstrate the construction principle of the forecasting model. Finally, in order to evaluate the predictive power of support vector machines, we compare their performance with the neural network model. The results show that the SVM model has a better performance in both the trend and the forecast precision, which can provide a powerful tool for the shipping market operators and investors to grasp the market trend and avoid the price risk.

关键词： BDI support vector machine feature selection CFS modeling

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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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