The paper deals with the problem of simultaneously assignment of servers replica location, topology, channel capacities and flow routes in the wide area network. Two important cost constraints have been considered dur...
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ISBN:
(纸本)9780889866379
The paper deals with the problem of simultaneously assignment of servers replica location, topology, channel capacities and flow routes in the wide area network. Two important cost constraints have been considered during the optimization process: server cost constraint and capacity cost (supporting cost of the network) constraint. In the paper an approximate algorithm for this widespread problem is proposed. Some computational experiments are reported in order to present the quality of the approximate solutions and to show some properties of the considered problem.
Most modem parallel computers are clusters using Myrinet or Ethernet communication networks. Several studies have been published comparing the performance of these two networks for parallelcomputing, however these fo...
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ISBN:
(纸本)9780889866379
Most modem parallel computers are clusters using Myrinet or Ethernet communication networks. Several studies have been published comparing the performance of these two networks for parallelcomputing, however these focus on average performance, and do not address the distributions of communication times, which can have long tails due to contention effects. In the case of Ethernet with TCP, retransmit timeouts (RTOs) can also occur. Slow communication events may have significant impact, particularly for applications requiring frequent synchronization, where the performance is determined by the slowest process. We have analysed the distributions of communication times for standard MPI routines on Ethernet with TCP and Myrinet with GM communications networks on the same cluster, and studied the scalability of the distributions as the number of communicating processes is increased, and the effect of RTOs for Ethernet with TCP.
In this paper we propose a new load balancing algorithm for the grid computing service. The proposed load balancing is based on the CPU speed of the workers in the grid system. We developed a simulation model using NS...
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ISBN:
(纸本)9780889866379
In this paper we propose a new load balancing algorithm for the grid computing service. The proposed load balancing is based on the CPU speed of the workers in the grid system. We developed a simulation model using NS2 to evaluate the performance of our load balancing algorithm. Our simulation results show an asymptotically optimal behaviour of our load balancing algorithms.
Active and passive replication are powerful techniques to improve the quality of multimedia streaming. Most systems follow either the active or the passive approach. A well known example for active replication are Con...
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ISBN:
(纸本)9780889866379
Active and passive replication are powerful techniques to improve the quality of multimedia streaming. Most systems follow either the active or the passive approach. A well known example for active replication are Content Distribution networks [8] that replicate data to predefined static locations. In contrast to that, P2P file sharing networks [2, 1] use passive replication where identical content is usually provided by different peers. We suggest a system that combines both techniques using Proxy Affinity, Request Affinity and Replication Affinity considering user preferences, user behaviour, hardware resources and networks capabilities.
We consider a wavelength division multiplexing (WDM) optical,tree network with converters available at a designated subset of nodes only. We provide a linear algorithm to assign an available wavelength for each link s...
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ISBN:
(纸本)9780889866386
We consider a wavelength division multiplexing (WDM) optical,tree network with converters available at a designated subset of nodes only. We provide a linear algorithm to assign an available wavelength for each link such that, with the help of a minimum number of converters, each node can send messages to all the others. It generalizes ail earlier algorithm in which converters are available at all nodes.
In a Spiking Neural networks (SNN), spike emissions are sparsely and irregularly distributed both in time and in the network architecture. Since a current feature of SNNs is a low average activity, efficient implement...
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ISBN:
(纸本)088986568X
In a Spiking Neural networks (SNN), spike emissions are sparsely and irregularly distributed both in time and in the network architecture. Since a current feature of SNNs is a low average activity, efficient implementations of SNNs are usually based on an Event-Driven Simulation (EDS). On the other hand, simulations of large scale neural networks can take advantage of distributing the neurons on a set of processors (either workstation cluster or parallel computer). This article presents a large scale SNN simulation framework able to gather the benefits of EDS and parallelcomputing. Two levels of parallelism are combined: distributed mapping of the neural topology, at the network level, and local multithreaded allocation of resources for simultaneous processing of events, at the neuron level. Based on the causality of events, a distributed solution is proposed for solving the complex problem of scheduling without synchronization barrier.
In this paper, the design and implementation of a recently developed clustering algorithm NNCA [1], Nearest Neighhour Clustering Algorithm, is proposed in conjunction with a Fast K Nearest Neighbour (FKNN) strategy fo...
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ISBN:
(纸本)9780889866379
In this paper, the design and implementation of a recently developed clustering algorithm NNCA [1], Nearest Neighhour Clustering Algorithm, is proposed in conjunction with a Fast K Nearest Neighbour (FKNN) strategy for further reduction in processing time. The parallel algorithm (PNNCA) has the ability to cluster pixels of retinal images into those belonging to blood vessels and others not belonging to blood vessels in a reasonable time.
The paper presents an approach to QoS management in distributed service oriented systems. We study the approach by the example of the Cassandra Framework developed at Philips Research. Cassandra is a distributed video...
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ISBN:
(纸本)9780889866379
The paper presents an approach to QoS management in distributed service oriented systems. We study the approach by the example of the Cassandra Framework developed at Philips Research. Cassandra is a distributed video/audio streaming and analysis platform consisting of a collection of loosely-coupled services, which can be easily combined to build distributed applications. To manage QoS of the system, two QoS attributes are selected: availability and performance. We tackle these issues in a service oriented fashion, making the system tolerant to service failures and adaptable to varying requirements of the applications.
We introduce a parallelized molecular dynamics (MD) simulation adapted for the IBM Blue Gene/L supercomputer. We begin by describing the parallel MD code. Next we discuss how parallel MD was tuned for Blue Gene/L. We ...
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ISBN:
(纸本)9780889866379
We introduce a parallelized molecular dynamics (MD) simulation adapted for the IBM Blue Gene/L supercomputer. We begin by describing the parallel MD code. Next we discuss how parallel MD was tuned for Blue Gene/L. We then show the results for some test targets, related to disease associated proteins, that we have run on Blue Gene/L and the efficiency we have achieved. Finally, we mention some future directions that we envisage undertaking as a continuation of this project.
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