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Does Amplify-and-Forward Cooperative Relay Improve OFDM/OFDMA Ergodic Capacity？

China Communications 2014年第2期11卷 83-89页

作者： HUANGFU Wei ZHANG Zhongshan ZHANG Dandan LONG Keping School of Computer and Communication Engineering Beijing Engineering and Technology Center for Convergence Networks andUbiquitous Services University of Science and Technology Beijing (USTB) No. 30Xueyuan Road Haidian District Beijing China 100083 National Mobile Communications Research Laboratory Southeast University Nanjing China 210096

The ergodic information rate for Orthogonal Frequency-Division Multiplexing / Orthogonal Frequency-Division Multiple Access with amplify-and-forward （AF） relaying systems in the presence of frequency offsets is evaluated. Unlike previous work, per-subcarrier adaptive power allocation is performed on each relay to optimize the system ergodic information rate. For a given frequency offset and total number of relays M, the AF ergodic information rate is proven to be a monotonically increasing function of α （the ratio of the power allocated to the source node and the total transmit power）, implying that the maximum ergodic information rate can be obtained at α=1 （i.e., there is no cooperative relay）. Furthermore, the proof of ＂cooperative relays cannot improve the AF ergodic information rate in a quasi-static wireless channel＂ is also provided in this letter.

关键词： cooperation amplify-ano-forward （AF） ergodic information rate frequency offset Orthogonal Frequency-Division Multiplexing （OFDM） OrthogonalFrequency-Division Multiple Access（OFDMA）

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Self-Organization Approaches for Optimization in Cognitive Radio Networks

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China Communications 2014年第4期11卷 121-129页

作者： XU Xu CHAI Xiaomeng ZHANG Zhongshan School of Computer & Communication Engineering and Beijing Engineering and Technology Center for Convergence Networks and Ubiquitous Services University of Science and Technology Beijing (USTB) No.30 Xueyuan Road Haidian District Beijing 100083 China National Mobile Communications Research Laboratory Southeast University Nanjing 210096 China

Cognitive radio(CR) is regarded as a promising technology for providing a high spectral efficiency to mobile users by using heterogeneous wireless network architectures and dynamic spectrum access ***,cognitive radio networks(CRNs)may also impose some challenges due to the ever increasing complexity of network architecture,the increasing complexity with configuration and management of large-scale networks,fluctuating nature of the available spectrum,diverse Quality-of-Service(QoS)requirements of various applications,and the intensifying difficulties of centralized control,*** management functions with self-organization features can be used to address these challenges and realize this new network *** this paper,fundamentals of CR,including spectrum sensing,spectrum management,spectrum mobility and spectrum sharing,have been surveyed,with their paradigms of self-organization being *** aspects of selforganization paradigms in CRNs,including critical functionalities of Media Access Control(MAC)- and network-layer operations,are surveyed and ***,new directions and open problems in CRNs are also identified in this survey.

关键词： cognitive radio self-organized networking heterogeneous machine-to-machine decentralized load balancing cooperation.

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Dominant Skyline Query Processing over Multiple Time Series

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Journal of computer science & technology 2013年第4期28卷 625-635页

作者：汪浩王朝坤徐亚军宁苑池 Department of Computer Science and Technology Tsinghua University Tsinghua National Laboratory for Information Science and Technology Key Laboratory for Information System Security Ministry of Education School of Software Tsinghua University

Multiple time series （MTS）, which describes an object in multi-dimensions, is based on single time series and has been proved to be useful. In this paper, a new analytical method called α/β-Dominant-Skyline on MTS and a formal definition of the α/β-dominant skyline MTS are given. Also, three algorithms, called NL, BC and MFB, are proposed to address the α/β-dominant skyline queries over MTS. Finally experimental results on both synthetic and real data verify the correctness and effectiveness of the proposed method and algorithms.

关键词： multiple time series α/β-dominant skyline skyline query processing

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A group member search method based on similarity analysis of mobile patterns

A group member search method based on similarity analysis of...

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International Conference on Intelligent Control and Information Processing (ICICIP)

作者： Qiang Yang Bing Huang Xiaojun Zeng Science and Technology on Information System Engineering Laboratory National University of Defense Technology Changsha P. R. China School of Computer Science University of Manchester Manchester United Kingdom

ISBN: (纸本)9781479936519

Searching for the group members that participate in a joint action based on collecting and analyzing the position information of moving objects could provide an important support for the decision makers in the fields such as the investigation of criminal cases, group emergency disposal, a large-scale military action etc. Following the pattern analysis of mobile objects based on their position information, this paper proposes a group member search method for mobile objects based on pattern similarity, which identifies group members by utilizing the correlation information of the mobility attributes such as trajectory, speed, direction and acceleration. Compared with group clustering or classification based on trajectory distance, the overlapping interference can be effectively avoided between members in different groups, and this method fits the objective law of group movement better. Combining with the application background, the experimental analysis confirms that the proposed method can quickly and accurately find the group members.

关键词： Trajectory Correlation Correlation coefficient Time series analysis Acceleration Bismuth Mobile communication

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A Group Member Search Method Based on Incremental Trajectories Data

A Group Member Search Method Based on Incremental Trajectori...

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International Symposium on Computational Intelligence and Design, ISCID

ISBN: (纸本)9781479970063

Searching group members in real time based on trajectory data is one of important researches in group mobility patterns analysis. Based on the incremental trajectory data, this paper proposed a dynamic analysis method of trajectory data on the basis of motion attributes similarity such as position, speed, direction, acceleration, in which the members of the same group can be quickly searched in real time. Using time window and dynamic refreshing strategy of similarity, this method not only ensures the algorithm efficiency, but also takes into account the impact of historical trajectory data on finding group members at the same time. Combined with the experiments in specific application, the sensitivity analysis of the main parameters was given.

关键词： Trajectory Correlation Time series analysis Acceleration Real-time systems Semantics Correlation coefficient

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ProvenanceLens: Service provenance management in the cloud

ProvenanceLens: Service provenance management in the cloud

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International Conference on Collaborative computing: Networking, Applications and Worksharing (CollaborateCom)

作者： Tao Li Ling Liu Xiaolong Zhang Kai Xu Chao Yang Hubei Province Key Laboratory of Intelligent Information Processing and Real-time Industrial System School of Computer Wuhan University of Science and Technology School of Computer Science. Georgia Institute of Technology Atlanta GA USA Computer Science and Information Engineering Hubei University Wuhan China

ISBN: (纸本)9781479953288

Service provenance can be defined as a profile of service execution history. Queries of service provenance data can answer questions such as when and by whom a server is invoked? which services operate on this data? What might be the root cause for the service failure? Most of the organizations today collect and manage their own service provenance in order to trace service execution failures, locate service bottlenecks, guide resource allocation, detect and prevent abnormal behaviors. As services become ubiquitous, there is an increasing demand for proving service provenance management as a service. This paper describes ProvenanceLens, a two-tier service provenance management framework. The top tier is the service provenance capturing and storage subsystem and the next tier provides analysis and inference capabilities of service provenance data, which are value-added functionality for service health diagnosis and remedy. Both tiers are built based on the service provenance data model, an essential and core component of ProvenanceLens, which categorizes all service provenance data into three broad categories: basic provenance, composite provenance and application provenance. In addition, ProvenanceLens provides a suite of basic provenance operations, such as select, trace, aggregate. The basic provenance data is collected through a light-weight service provenance capturing subsystem that monitors service execution workflows, collects service profiling data, encapsulates service invocation dependencies. The composite and application provenance data are aggregated through a selection of provenance operations. We demonstrate the effectiveness of ProvenanceLens using a real world educational service currently in operation for a dozen universities in China.

关键词： Silicon Analytical models Data models Computational modeling

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A 0.8V, 560fJ/bit, 14Gb/s injection-locked receiver with input duty-cycle distortion tolerable edge-rotating 5/4X sub-rate CDR in 65nm CMOS

A 0.8V, 560fJ/bit, 14Gb/s injection-locked receiver with inp...

引用

28th IEEE Symposium on VLSI Circuits, VLSIC 2014

作者： Li, Hao Chen, Shuai Yang, Liqiong Bai, Rui Hu, Weiwu Zhong, Freeman Y. Palermo, Samuel Chiang, Patrick Yin School of Electrical Engineering and Computer Science Oregon State University Corvallis OR 97331 United States Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China Texas A and M University College Station TX 77843 United States State Key Laboratory of ASIC and System Fudan University Shanghai 200433 China LSI Corporation San Jose CA 95131 United States

ISBN: (纸本)9781479933273

A quarter-rate forwarded-clock receiver utilizes an edge-rotating 5/4X sub-rate CDR for improved jitter tolerance with low power overhead relative to conventional 2X oversampling CDR systems. Low-voltage operation is achieved with efficient quarter-rate clock generation from an injection-locked oscillator (ILO) and through automatic independent phase rotator control that optimizes timing margin of each input quantizer in the presence of receive-side clock static phase errors and transmitter duty-cycle distortion (DCD). Fabricated in GP 65nm CMOS, the receiver operates up to 16Gb/s with a BER-12, achieves a 1MHz phase tracking bandwidth, tolerates ±50%UIpp DCD on input data, and has 14Gb/s energy efficiency of 560fJ/bit at V DD=0.8V. © 2014 IEEE.

关键词： Clocks

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Accelerate mapreduce on GPUs with multi-level reduction 13

Accelerate mapreduce on GPUs with multi-level reduction

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5th Asia-Pacific Symposium on Internetware, Internetware 2013

作者： Zheng, Ran Liu, Kai Jin, Hai Zhang, Qin Feng, Xiaowen Services Computing Technology and System Lab School of Computer Science and Technology Huazhong University of Science and Technology Wuhan 430074 China

ISBN: (纸本)9781450323697

With Graphics Processing Units (GPUs) becoming more and more popular in general purpose computing, more attentions have been paid on building a framework to provide convenient interfaces for GPU programming. MapReduce can greatly simplify the programming for data-parallel applications in cloud computing environment, and it is also naturally suitable for GPUs. However, there are some problems in recent reduction-based MapReduce implementation on GPUs. Its performance is dramatically degraded when handling massive distinct keys because the massive data cannot be stored in tiny shared memory entirely. A new MapReduce framework on GPUs, called Jupiter, is proposed with continuous reduction structure. Two improvements are supported in Jupiter, a multi-level reduction scheme tailored for GPU memory hierarchy and a frequencybased cache policy on key-value pairs in shared memory. Shared memories are utilized efficiently for various dataparallel applications whether involving little or abundant distinct keys. Experiments show that Jupiter can achieve up to 3x speedup over the original reduction-based GPU MapReduce framework on the applications with lots of distinct keys. Categories and Subject Descriptors D.1.3 [Programming Techniques]: Concurrent Programming- parallel programming General Terms Algorithms, Performance, Design.

关键词： MapReduce

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Adaptively secure key-policy ABE scheme with fast decryption

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Tongxin Xuebao/Journal on Communications 2014年 35卷 26-32页

作者： Li, Qi Ma, Jian-Feng Xiong, Jin-Bo Liu, Xi-Meng School of Computer Science and Technology Xidian University Xi'an710071 China Shaanxi Key Laboratory of Network and System Security Xidian University Xi'an710071 China Science and Technology on Communication Information Security Control Laboratory Jiaxing314033 China Faculty of Software Fujian Normal University Fuzhou350108 China School of Telecommunication Engineering Xidian University Xi'an710071 China

In the existing adaptively secure ABE (attribute-based encryption) schemes, the decryption cost goes linearly with the number of attributes that are used in decryption. An adaptively secure key-policy ABE (FKP-ABE) scheme with fast decryption is proposed, where constant size of computation overhead is implemented in decryption. This scheme is constructed on composite order bilinear groups and supports any monotonic access structure that can be expressed by LSSS (linear secret sharing schemes). The proposed scheme is proved to be adaptively secure in the standard model. ©, 2014, Editorial Board of Journal on Communications. All right reserved.

关键词： Cryptography

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Design and implementation of multiple volume servers block level storage system based on load-balanced strategy

International Journal of Database Theory and Application

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International Journal of Database Theory and Application 2014年第4期7卷 59-78页

作者： Wan, Jian Chen, Xun You, Xindong School of Computer Science and Technology Hangzhou Dianzi University Hangzhou China Key Laboratory of Complex System Modeling and Simulation Ministry of Education China

Block level storage system has been widely used as it can provide users raw block device. On the basis of Orthrus system, this paper designs and implements a multiple volume servers block level storage system based on load-balanced strategy-Orthrus Plus. This system uses the dynamic load-balanced strategy based on genetic algorithm strategy to load balance the volume servers clusters and proposes an iSCSI pause and resume method to solve the breakpoint retransmission problem during load-balancing. At last, we design a hierarchical management mechanism based on volume life cycle at storage. Experiments show that the load balancing capability in Orthrus Plus is more accurate and efficient under the situation of larger amount of data, and the hierarchical storage strategy also increases the I/O throughout capacity. © 2013 SERSC.

关键词： Genetic algorithms

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