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16th International Symposium on High Performance distributed Computing 2007, HPDC'07 and Co-Located workshops

作者： Eger, Kolja Hoßfeld, Tobias Binzenhöfer, Andreas Kunzmann, Gerald Institute of Communication Networks Germany University of Würzburg Institute of Computer Science Germany Technical University of Munich Institute of Communication Networks Germany

ISBN: (纸本)1595937188

Peer-to-peer (P2P) networks can reduce the distribution cost of large media files for the original provider of the data significantly. Thereby, the BitTorrent protocol is widely used in the Internet today. Most research work studies the protocol analytically, by simulations at the flow-level or real world experiments. Thereby, for flow-level simulations the influence of neglecting packet-level characteristics is not yet quantified. Therefore, this paper compares packet-level simulation results with flow-level values and analytically derived bounds. Our findings show that BitTorrent is near to optimal at flow-level for different scenarios. Naturally, packet-level results deviate more from the optimal values but differences are at most around 30% in our simulations. Furthermore, we show that the propagation delay can significantly influence the download performance of BitTorrent.

关键词： Computer networks

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Design, simulation and measurement analysis on the S-parameters of an inductively-degenerated common-source open-drain cascode low noise amplifier

Design, simulation and measurement analysis on the S-paramet...

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IEEE International workshop on Radio-Frequency Integration Technology

作者： Noh, Norlaili Mohd Zulkifli, Tun Zainal Azni Univ Sains Malaysia RFIC Mixed Signal Grp RMIC Pulau Pinang Malaysia

ISBN: (纸本)9781424413072

An inductively-degenerated common-source (CS) open-drain cascode LNA was designed for W-CDMA application. The operating frequency for the design was at 2.14 GHz which is at the center of the reception range Of the W-CDMA standard. The supply voltage is 1.8V at 0.18 mu m CMOS process. The LNA was designed using power-constrained noise optimization method in obtaining the width of the transistor of 290 gm. Post-layout simulations with distributed resistors and capacitors were performed. On-chip inductors with quality factor of 8 were utilized to resonate with the metal-insulator-metal capacitor (mimcap). The mimcap was also used to isolate V-DD and ground. The input was 50 Omega matched using the transistor as well as an inductor at the gate and three parallel 1.65 nH inductors acting as a 0.55 nH degeneration inductor at the source. Detailed design steps are described in this paper wih plots of the post-layout simulation and measurement results provided. These plots are analyzed extensively in this paper and justification for the errors are given. The 12.8 dB of S-21 obtained from the post-layout and a much less 7.8 dB from the measurement shows that there is an offset by 5 dB. Derivations are given to show that the unmatched output is the cause of the gain offset. S-11 is measured at -24 dB which is very close to the simulated value of -25.4 dB. The current measured and simulated at a bias voltage of 0.65 V is 4.1 mA.

关键词： inductively degenerated common-source open-drain cascode W-CDMA

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Enabling rapid development of parallel tree search applications

Proceedings of the 5th IEEE Workshop on Challenges of Large ...

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proceedings of the 5th IEEE workshop on Challenges of Large Applications in distributed Environments, CLADE'07 2007年 1-10页

作者： Gardner, Jeffrey P. Connolly, Andrew McBride, Cameron Pittsburgh Supercomputing Center 300 S. Craig St. Pittsburgh PA 15213 University of Washington Department of Astronomy Seattle WA 98195 University of Pittsburgh Department of Physics and Astronomy 3941 O'Hara St. Pittsburgh PA 15260

ISBN: (纸本)1595937145

Virtual observatories will give astronomers easy access to anunprecedented amount of data. Extracting scientific knowledge from these data will increasingly demand both efficient algorithms as well as the power of parallel computers. Nearly all efficient analyses of large astronomical datasets use trees as their fundamental data structure. Writing efficient tree-based techniques, a task that is time-consuming even on single-processor computers, is exceedingly cumbersome on massively parallel platforms (MPPs). Most applications that run on MPPs are simulation codes, since the expense of developing them is offset by the fact that they will be used for many years by many researchers. In contrast, data analysis codes change far more rapidly, are often unique to individual researchers, and therefore accommodate little reuse. Consequently, the economics of the current high-performance computing development paradigm for MPPs does not favor data analysis applications. We have therefore built a library, called Ntropy, that provides a flexible, extensible, and easy-to-use way of developing tree-based data analysis algorithms for both serial and parallel platforms. Our experience has shown that not only does our library save development time, it can also deliver excellent serial performance and parallel scalability. Furthermore, Ntropy makes it easy for an astronomer with little or noparallel programming experience to quickly scale their application to a distributed multiprocessor environment. By minimizing development time for efficient and scalable data analysis, we enable wide-scale knowledge discovery on massive datasets. Copyright 2007 ACM.

关键词： Data reduction

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Routing problems in incomplete pancake graphs

Routing problems in incomplete pancake graphs

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7th ACIS International Conference on Software Engineering, Artificial Intelligence, Networking, and parallel and distributed Computing/7th ACIS International workshop on Self-Assembling Networks

作者： Kaneko, Keiichi Tokyo Univ Agr & Technol Inst Symbiot Sci & Technol Koganei Tokyo 1848588 Japan

ISBN: (纸本)076952611X

A pancake graph was proposed as a topology for interconnection networks of parallel computers, and it has a merit that it can connect many nodes with small diameter and small degree. However the number of nodes in a pancake graph must be equal to the factorial of an integer, which causes a demerit that it lacks incremental expandability. Hence, in this paper, we propose a graph, an incomplete pancake graph, that is obtained by deleting some of sub graphs of a pancake graph, and we give algorithms for the problems of the simple routing, the Hamiltonian cycle, the Hamiltonian path, and the container in incomplete pancake graphs.

关键词： Routing Network topology Multiprocessor interconnection networks Containers distributed computing Intelligent networks Agriculture Symbiosis Computer networks Concurrent computing

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proceedings: 20th workshop on Principles of Advanced and distributed simulation

Proceedings: 20th Workshop on Principles of Advanced and Dis...

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20th workshop on Principles of Advanced and distributed simulation, PADS 2006

ISBN: (纸本)0769525873

The proceedings contain 30 papers. The topics discussed include: improving lookahead in parallel multiprocessor simulation using dynamic execution path prediction;the distributed open network emulator: using relativistic time for distributed scalable simulation;performance analysis of shared data access algorithms for distributed simulation of multi-agent systems;predicting performance of resolution changes in parallel simulations;what comes after the semantic web? PADS implications for the dynamic web;discrete-event execution alternatives on general purpose graphical processing units;developing an hierarchical simulator for Beta-binders;greedy algorithms for client assignment in large-scale distributed virtual environments;and interest operators: facilitating attribute interest criteria for formula-based interest management in distributed virtual environments.

关键词： distributed computer systems

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Aurora: An approach to high throughput parallel simulation 06

Aurora: An approach to high throughput parallel simulation

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20th workshop on Principles of Advanced and distributed simulation, PADS 2006

作者： Park, Alfred Fujimoto, Richard M. Computational Science and Engineering Division College of Computing Georgia Institute of Technology Atlanta GA 30332-0280 United States

ISBN: (纸本)0769525873

A master/worker paradigm for executing large-scale parallel discrete event simulation programs over network-enabled computational resources is proposed and evaluated. In contrast to conventional approaches to parallel simulation, a client/server architecture is proposed where clients (workers) repeatedly download state vectors of logical processes and associated message data from a server (master), perform simulation computations locally at the client, and then return the results back to the server. This process offers several potential advantages over conventional parallel discrete event simulation systems, including support for execution over heterogeneous distributed computing platforms, load balancing, efficient execution on shared platforms, easy addition or removal of client machines during program execution, simpler fault tolerance, and improved portability. A prototype implementation called the Aurora parallel and distributed simulation System (Aurora) is described. The structure and interaction of the Aurora components is described. Results of an experimental performance evaluation are presented detailing primitive timings and application performance on both dedicated and shared computing platforms. © 2006 IEEE.

关键词： parallel processing systems

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Improving lookahead in parallel multiprocessor simulation using dynamic execution path prediction 06

Improving lookahead in parallel multiprocessor simulation us...

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20th workshop on Principles of Advanced and distributed simulation, PADS 2006

作者： Chung, Moo-Kyoung Kyung, Chong-Min Dynalith Systems Co. Ltd. CHiPS KAIST Daejeon Korea Republic of Department of EECS CHiPS KAIST Daejeon Korea Republic of

ISBN: (纸本)0769525873

simulation performance is dominated by lookahead in null message-based conservative time management of parallel discrete event simulation (PDES). This paper proposes a scheme for software execution path prediction to extend lookahead in parallel multiprocessor simulation. Templates for predicting program execution path are generated by software analysis, then, a processor model gets lookaheads by evaluating the templates at simulation time. We reduced the amount of null messages by a factor of 10 to 50 in parallel simulation with eight clustered workstations and, as a result, achieved a speedup factor of 4 to 7 compared to a conventional method having constant lookahead. © 2006 IEEE.

关键词： Program processors

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Node-disjoint multipath routing and distributed cross-layer QoS guarantees in mobile ad hoc networks

Node-disjoint multipath routing and distributed cross-layer ...

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7th ACIS International Conference on Software Engineering, Artificial Intelligence, Networking, and parallel and distributed Computing/7th ACIS International workshop on Self-Assembling Networks

作者： Li, Xuefei Cuthbert, Laurie Queen Mary Univ London Dept Elect Engn London England

ISBN: (纸本)076952611X

In this paper, a novel distributed Cross-Layer QoS (DCLQ) architecture based on node disjoint multipath routing is proposed to provide QoS guarantees for realtime traffic and best-effort traffic in mobile ad hoc networks. Without any extra control overhead, DCLQ can schedule packets of real-time flows according to their perhop QoS requirements. DCLQ implements per-hop delay QoS-aware priority scheduling and QoS consideration of IvMC layer to ensure that real-timeflows and best-effort flows can achieve their desired service level.

关键词： Routers

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Progressive time-parallel simulation 06

Progressive time-parallel simulation

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20th workshop on Principles of Advanced and distributed simulation, PADS 2006

作者： Kiesling, Tobias Fakultät für Informatik Universität der Bundeswehr München 85577 Neubiberg Germany

ISBN: (纸本)0769525873

parallel simulation techniques are designed to increase simulation model performance by exploiting model concurrency. Unfortunately, designing efficient parallel simulations is not always an easy task. Most existing techniques guarantee results identical to a corresponding sequential simulation. Other methods try to increase efficiency by relaxing causal constraints, leading to the calculation of approximate results. This work proposes to combine both approaches using the novel technique of progressive time-parallel simulation, where imprecise results are calculated rapidly and improved progressively later on until precise results are known. The user is allowed to cancel this process at any time if the accuracy is satisfying. Progressive time-parallel simulation is a specialized parallelization approach that is not applicable to every kind of simulation model. Possible application areas include simulation-based decision support or simulation-based scheduling and control of manufacturing systems. A successful application of the technique is illustrated with progressive queuing system simulation. © 2006 IEEE.

关键词： parallel processing systems

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Optimal period of workload redistribution for dynamic bulk synchronous computations in heterogeneous computing systems

Optimal period of workload redistribution for dynamic bulk s...

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3rd International workshop on Performance Modelling, Evaluation, and Optimization of parallel and distributed Systems held in Conjunction with the 18th International parallel and distributed Processing Symposium

作者： Li, KQ SUNY Albany Dept Comp Sci New Paltz NY 12561 USA

ISBN: (纸本)0769521320

In dynamic bulk synchronous computations, processors may change their workloads from phase to phase. Such workload change will possibly increase the duration of a phase and the overall parallel execution time. Therefore, it is necessary to redistribute workload at runtime to reduce the parallel time. However, such workload redistribution at runtime can be expensive and the overhead of frequent runtime workload redistribution may exceed the benefit of workload redistribution and balancing. The problem of finding the optimal period of runtime workload redistribution for dynamic bulk synchronous computations is motivated by the combined consideration of parallel execution time and system overhead for workload redistribution and balancing. We develop an analytical method to solve the problem in heterogeneous computing systems. We also demonstrate numerical data of the analytical method and simulation results that verify the analytical data.

关键词： bulk synchronous computation heterogeneous computing system simulation workload redistribution

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