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作者： Song, Xiaoshi Yin, Changchuan Liu, Danpu Zhang, Rui Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Beijing100876 China Department of Electrical and Computer Engineering National University of Singapore Singapore117576 Singapore

This paper studies the opportunistic spectrum access (OSA) of the secondary users in a large-scale overlay cognitive radio (CR) network. Two threshold-based OSA schemes, namely the primary receiver assisted (PRA) protocol and the primary transmitter assisted (PTA) protocol, are investigated. Under the PRA/PTA protocols, a secondary transmitter (ST) is allowed to access the spectrum only when the maximum signal power of the received beacons/pilots sent from the active primary receivers/transmitters (PRs/PTs) is lower than a certain threshold. To measure the resulting transmission opportunity for the secondary users by the proposed OSA protocols, the concept of spatial opportunity, which is defined as the probability that an arbitrary location in the primary network is detected as a spatial spectrum hole, is introduced and then evaluated by applying tools from stochastic geometry. Based on spatial opportunity, the coverage (non-outage transmission) performance in the overlay CR network is analyzed. With the obtained results of spatial opportunity and coverage probability, we finally characterize the spatial throughput, which is defined as the average spatial density of successful transmissions in the primary/secondary network, under the PRA and PTA protocols, respectively. © 1983-2012 IEEE.

关键词： Cognitive radio

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A business model for video transmission services using dynamic adaptation streaming over HTTP 9

A business model for video transmission services using dynam...

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9th Advanced International Conference on Telecommunications, AICT 2013

作者： Rodríguez, Demóstenes Zegarra Rosa, Renata Lopes Bressan, Graça Laboratory of Computer Architecture and Networks Computer and Digital System Engineering Department University of São Paulo São Paulo Brazil

ISBN: (纸本)9781612082790

A business model for video transmission services is proposed that uses the Dynamic Adaptation Streaming over HTTP (DASH) mechanism using different versions of the same video. These video versions are encoded using different parameters, such as spatial resolution or number of frames per second. The transmission of each video version depends on the capabilities of the network at the end user point. The business model proposed considers different costs for each version of video fragments transmitted. The costs of video resolution upgrade are predefined by the service provider and used during the video streaming. Also, in this model, the user can either accept or reject an upgrade. Subjective tests were performed using different spatial resolutions of the same video, in which the interest level of users to perform a video upgrade is evaluated. Furthermore, the network architecture of the proposed solution is presented and the technical feasibility to deploy the proposed solution in commercial networks is shown. As a consequence, the proposed solution can improve the earnings of the video service provider. Copyright © 2013 IARIA.

关键词： Video streaming

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Parallelized Jaccard-Based Learning Method and MapReduce Implementation for Mobile Devices Recognition from Massive Network Data

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China Communications 2013年第7期10卷 71-84页

作者：刘军李银周 Felix Cuadrado Steve Uhlig 雷振明 Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications Department of Electronic Engineering and Computer Science Queen MaryUniversity of London

The ability of accurate and scalable mobile device recognition is critically important for mobile network operators and ISPs to understand their customers' behaviours and enhance their user *** this paper,we propose a novel method for mobile device model recognition by using statistical information derived from large amounts of mobile network traffic ***,we create a Jaccardbased coefficient measure method to identify a proper keyword representing each mobile device model from massive unstructured textual HTTP access *** handle the large amount of traffic data generated from large mobile networks,this method is designed as a set of parallel algorithms,and is implemented through the MapReduce framework which is a distributed parallel programming model with proven low-cost and high-efficiency *** using real data sets show that our method can accurately recognise mobile client models while meeting the scalability and producer-independency requirements of large mobile network *** show that a 91.5% accuracy rate is achieved for recognising mobile client models from 2 billion records,which is dramatically higher than existing solutions.

关键词： mobile device recognition data mining Jaccard coefficient measurement distributed computing MapReduce

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Software ecosystems governance to enable IT architecture based on software asset management

Software ecosystems governance to enable IT architecture bas...

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2013 7th IEEE International Conference on Digital Ecosystems and Technologies: Smart Planet and Cyber Physical systems as Embodiment of Digital Ecosystems, DEST 2013

作者： Albert, Benno E. Dos Santos, Rodrigo P. Werner, Claudia M. Technological Architecture Information Technology and Telecommunications Petrobras Rio de Janeiro Brazil System Engineering and Computer Science Department COPPE/UFRJ Federal University of Rio de Janeiro P.O. Box 68511 Rio de Janeiro 21945-970 Brazil

ISBN: (纸本)9781479907861

Information Technology (IT) supports companies' business processes and decision making through the use of technologies and tools that are provided by suppliers. Companies that are suppliers and consumers establish relationships through contracts of purchasing products and consulting, for example. These relationships, i.e., the companies involved and the information exchanged between the parties are considered elements of Software Ecosystems (SECOs). All of these elements can be considered SECO assets and need to be supported via SECO governance since their organization and evolution represent an IT architecture. So, IT companies or their IT divisions can use the ISO/IEC 19770 standard for Software Asset Management (SAM) in order to control costs and optimize software investments. In this sense, this paper describes a SECO Governance approach for enabling an IT architecture based on SAM. © 2013 IEEE.

关键词： Information technology

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Software ecosystems governance to enable IT architecture based on software asset management

Software ecosystems governance to enable IT architecture bas...

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Inaugural IEEE-IES Digital Ecosystems and Technologies Conference, DEST

作者： Benno E. Albert Rodrigo P. dos Santos Cláudia M. L. Werner Technological Architecture Information Technology & Telecommunications Petrobras Rio de Janeiro Brazil System Engineering and Computer Science Department COPPE Federal University of Rio de Janeiro Rio de Janeiro Brazil

关键词： Software Companies computer architecture Standards Ecosystems

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High-precision finite-element analysis of rubber bearing for base-isolation of building structures

High-precision finite-element analysis of rubber bearing for...

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4th International Conference on Computational Methods in Structural Dynamics and Earthquake engineering, COMPDYN 2013

作者： Ohsaki, Makoto Miyamura, Tomoshi Kohiyama, Masayuki Yamashita, Takuzo Yamamoto, Masashi Nakamura, Naohiro Department of Architecture Hiroshima University 1-4-1 Kagamiyama Higashi-Hiroshima 739-8527 Japan Department of Computer Science College of Engineering Nihon University 1 Nakagawara Tokusada Tamura Koriyama 963-8642 Japan Department of System Design Engineering Keio University 3-14-1 Hiyoshi Kohoku Yokohama 223-8522 Japan Hyogo Earthquake Eng. Res. Center National Res. Inst. for Earth Science and Disaster Prevention 1501-21 Nishikameyama Mitsuta Shijimi Miki 673-0515 Japan Construction Technology Department Takenaka Research and Development Institute 1-5-1 Ohtsuka Inzai 270-1395 Japan

ISBN: (纸本)9789609999427

Seismic response analysis is carried out for a base-isolated frame. The RC-frame members as well as the rubber bearings are discretized into hexahedral finite elements. The material properties of rubber are represented by the Ogden model, and the frame is assumed to remain in elastic range. The seismic response analysis of the frame, which has more than 3 million degrees of freedom is carried out using the E-Simulator, which is under development at E-Defense, Japan, based on a software package called ADVENTURECluster. It is shown that the global and local responses can be simultaneously evaluated through a high-precision finite element analysis.

关键词： Finite element method

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Dynamic collapse analysis of four-story steel frame using E-Simulator

Dynamic collapse analysis of four-story steel frame using E-...

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4th International Conference on Computational Methods in Structural Dynamics and Earthquake engineering, COMPDYN 2013

作者： Miyamura, Tomoshi Ohsaki, Makoto Yamashita, Takuzo Isobe, Daigoro Kohiyama, Masayuki Department of Computer Science College of Engineering Nihon University 1 Nakagawara Tokusada Tamura Koriyama 963-8642 Japan Department of Architecture Hiroshima University 1-4-1 Kagamiyama Higashi-Hiroshima 739-8527 Japan Hyogo Earthquake Eng. Res. Center National Res. Inst. for Earth Science and Disaster Prevention 1501-21 Nishikameyama Mitsuta Shijimi Miki 673-0515 Japan Division of Engineering Mechanics and Energy University of Tsukuba 1-1-1 Tennodai Tsukuba-shi Ibaraki 305-8573 Japan Department of System Design Engineering Keio University 3-14-1 Hiyoshi Kohoku Yokohama 223-8522 Japan

ISBN: (纸本)9789609999427

Dynamic collapse analyses of a 4-story steel building frame modeled by solid elements are performed using the E-Simulator, which is a parallel finite element analysis software package for civil and building structures. Code verification, calculation verification, and validation of the numerical codes (V&V) are conducted by comparing the results obtained by the E-Simulator, those obtained by a beam element analysis code, and the experimental results obtained by the 3-D full-scale earthquake testing facility, the E-Defense at NIED. The seismic response analyses under 60% or 100% of the JR Takatori seismic wave of the 1995 Hyogoken-Nanbu earthquake are performed. The shear forces and interstory drift angles of the 1st story obtained by the E-Simulator simulation and the E-Defense full-scale test have good agreement. Both response of the whole frame and local deformation due to plastic buckling are simulated in the analysis using the E-Simulator.

关键词： Finite element method

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A stochastic approach to the probability of failure on demand (PFD) with regard to the standard IEC 61508

A stochastic approach to the probability of failure on deman...

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11th International Probabilistic Safety Assessment and Management Conference and the Annual European Safety and Reliability Conference 2012, PSAM11 ESREL 2012

作者： Wacker, H.D. Ugljesa, E. Boercsoek, J. Department of Computer Architecture and System Programming Faculty of Electrical Engineering /Computer Science University Kassel Wilhelmshöher Allee 71 Germany

ISBN: (纸本)9781622764365

Let there be given a safety related electronic system suffering from random failures or errors. The standard IEC 61508 contains simplified equations for the probability of failure on demand PFDavg for special system architectures, mostly without proof. In various publications PFDavg is defined by several different equations, e.g. as a Laplacian probability, as an integral mean, or by means of the average failure rate of the system. The aim of the paper is to determine PFDavgby stochastic methods and to bring together the different definitions. A formula for PFDavg is given that is valid for most universal electronic systems. The equivalence of 2 different definitions of PFDavgis shown. The special case of a koon-system is investigated, and the resulting equations improve those known so far. The basic idea is to randomize the time to failure, the down time of the system, as well as the repair time, and then, by means of the Stieltjes-Integral, determine the mean or average time as the expectation of the respective random variable.

关键词： Stochastic systems

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Towards AER VITE: Building spike gate signal

Towards AER VITE: Building spike gate signal

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2012 19th IEEE International Conference on Electronics, Circuits, and systems, ICECS 2012

作者： Perez-Pena, Fernando Morgado-Estevez, Arturo Rioja-Del-Rio, Carlos Linares-Barranco, Alejandro Jimenez-Fernandez, Angel Lopez-Coronado, Juan Munoz-Lozano, Jose Luis Applied Robotics Lab High School of Engineering University of Cadiz Spain Automatic and System Engineering Department University Polytechnics of Cartagena Spain Department of Computer Architecture and Technology ETSI Computer Science University of Seville Spain

ISBN: (纸本)9781467312615

Neuromorphic engineers aim to mimic the precise and efficient mechanisms of the nervous system to process information using spikes from sensors to actuators. There are many available works that sense and process information in a spike-based way. But there are still several gaps in the actuation and motor control field in a spike-based way. Spike-based Proportional-Integrative- Derivative controllers (PID) are present in the literature. On the other hand, neuro-inspired control models as VITE (Vector Integration To End point) and FLETE (Factorization of muscle Length and muscle Tension) are also present in the literature. This paper presents another step toward the spike implementation of those neuro-inspired models. We present a spike-based ramp multiplier. VITE algorithm generates the way to achieve a final position targeted by a mobile robotic arm. The block presented is used as a gate for the way involved and it also puts the incoming movement on speed with a variable slope profile. Only spikes for information representation were used and the process is in real time. The software simulation based on Simulink and Xilinx system Generator shows the accurate adjust to the traditional processing for short time periods and the hardware tests confirm and extend the previous simulated results for any time. We have implemented the spikes generator, the ramp multiplier and the low pass filter into the Virtex-5 FPGA and connected this with an USB-AER (Address Event Representation) board to monitor the spikes. © 2012 IEEE.

关键词： Muscle

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A Discussion in Favor of Dynamic Scheduling for Regular Applications in Many-core architectures

A Discussion in Favor of Dynamic Scheduling for Regular Appl...

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IEEE International Symposium on Parallel and Distributed Processing Workshops and Phd Forum (IPDPSW)

作者： Elkin Garcia Daniel Orozco Robert Pavel Guang R. Gao Computer Architecture and Parallel System Laboratory (CAPSL) Electrical and Computer Engineering Department University of Delaware Newark DE USA

ISBN: (纸本)9781467309745

The recent evolution of many-core architectures has resulted in chips where the number of processor elements (PEs) are in the hundreds and continue to increase every day. In addition, many-core processors are more and more frequently characterized by the diversity of their resources and the way the sharing of those resources is arbitrated. On such machines, task scheduling is of paramount importance to orchestrate a satisfactory distribution of tasks with an efficient utilization of resources, especially when fine-grain parallelism is desired or required. In the past, the primary focus of scheduling techniques has been on achieving load balancing and reducing overhead with the aim to increase total performance. This focus has resulted in a scheduling paradigm where Static Scheduling (SS) is preferred to Dynamic Scheduling (DS) for highly regular and embarrassingly parallel applications running on homogeneous architectures. We have revisited the task scheduling problem for these types of applications under the scenario imposed by many-core architectures to investigate whether or not there exists scenarios where DS is better than SS. Our main contribution is the idea that, for highly regular and embarrassingly parallel applications, DS is preferable to SS in some situations commonly found in many-core architectures. We present experimental evidence that shows how the performance of SS is degraded by the new environment on many-core chips. We analyze three reasons that contribute to the superiority of DS over SS on many-core architectures under the situations described: 1) A uniform mapping of work to processors without considering the granularity of tasks is not necessarily scalable under limited amounts of work. 2) The presence of shared resources (i.e. the crossbar switch) produces unexpected and stochastic variations on the duration of tasks that SS is unable to manage properly. 3) Hardware features, such as in-memory atomic operations, greatly contribute to decrea

关键词： Tiles computer architecture Dynamic scheduling Random access memory Throughput Hardware Instruction sets

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