Although originally fostering the principle of free resource sharing, academia has identified the need for charging mechanisms for grid services offered in order to better control resource usage. Within the IT industr...
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ISBN:
(纸本)9780889866379
Although originally fostering the principle of free resource sharing, academia has identified the need for charging mechanisms for grid services offered in order to better control resource usage. Within the IT industry on the other hand, numerous initiatives are aiming at creating commercial grid services. Both need payment systems but most of the available solutions are bespoke. We present a certificate based payment solution that requires no modification of existing middleware APIs. This transparency guarantees seamless operation with deployed, non-payment aware grid infrastructures and enables hence the simultaneous and interchangeable use of free and paid for grid services. GridBank, the central component in our prototype implementation, both issues and redeems digitally signed cheques. The only common nominator being certificate based authentication allows GridBank to be integrated not only to grid middleware but also to any software infrastructure leveraging X.509 certificates for authentication. We compare our solution to other existing payment solutions for grids, describe its detailed architecture and conclude by analysing its features, strengths and weaknesses.
In mobile ad hoc networks (MANETs) dynamic service composition is mandatory because of the permanently changing environment by reason of mobility and resource variability. Moreover, dynamic composition alone is not su...
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ISBN:
(纸本)9780889866386
In mobile ad hoc networks (MANETs) dynamic service composition is mandatory because of the permanently changing environment by reason of mobility and resource variability. Moreover, dynamic composition alone is not sufficient because devices could typically be very resource-constrained and the resource situation may change rapidly, e.g. battery power may fade away, or due to memory limits a service may not currently run on a device, though it is available in principle. In this paper, we introduce a dynamic service composition approach with two novel aspects. First, we focus on finding dynamic compositions for end-to-end functional descriptions even if functional nodes contained in that description are not directly compatible. Second, we address resource optimization based on simple rules, but with powerful means, such as deployment provisioning and migration of services and components within an ad hoc network.
A mobile ad hoc network (MANET) is an autonomous System of mobile nodes connected by wireless links. which cooperatively and spontaneously form an IP-based network. These networks are infrastructure-free where central...
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ISBN:
(纸本)088986568X
A mobile ad hoc network (MANET) is an autonomous System of mobile nodes connected by wireless links. which cooperatively and spontaneously form an IP-based network. These networks are infrastructure-free where central administration or configuration by the user are impractical. On the other hand, the Dynamic Host Configuration Protocol (DHCP) was designed to provide configuration parameters to Internet hosts, so it was not itself designed for the purpose of providing host mobility. In this paper, we present an updating of DHCP designed to configure nodes in a mobile multi-hop ad hoc network. This approach considers problems as abruptly departure of nodes, network partitioning and merging, adding new characteristics to the original protocol. Finally, we evaluate the performance of the solution through simulation experiments.
A computational grid is a widespread computing environment that provides huge computational power for large-scale distributed applications. One of the most important issues in such an environment is resource managemen...
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ISBN:
(纸本)0889865701
A computational grid is a widespread computing environment that provides huge computational power for large-scale distributed applications. One of the most important issues in such an environment is resource management for which agent-based approaches are appropriate. Load balancing as a part of resource management, has a considerable effect on performance. Ant colony is a metaheuristic that can be instrumental for grid load balancing. This paper presents an echo system of intelligent, autonomous and cooperative ants. The ants in this environment can procreate and also may commit suicide depending on existing conditions. A new concept called Ant level load balancing is presented for improving the performance of the mechanism. A performance evaluation model is derived. Theoretical analyses and simulation results indicate that this new mechanism surpasses its predecessor.
parallel algorithm of time-independent Monte Carlo transport problem is successful because particles are typically independent and easily distributed to multiple processors. However, for time-dependent Monte Carlo tra...
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ISBN:
(纸本)0889865701
parallel algorithm of time-independent Monte Carlo transport problem is successful because particles are typically independent and easily distributed to multiple processors. However, for time-dependent Monte Carlo transport problem, due to the communication of each time-step about scattering source attribute and meshes, it reduces the parallel efficiency and limits enlarge of parallel scale. We research two algorithms. Where adaptive processor assignment and the optimized processor choice are obtained. We propose a scheme that is based upon Monte Carlo stratified sampling technique for treatment of scattering source communication. It greatly reduces the communication cost. The parallel scalability is obviously improved. The larger speedup over the basic algorithm is obtained.
In this paper, we propose a simple parallel algoritm for solving the largest empty rectangle problem in discrete domain on a rectangular pixel grid. Our algorithm has a computational complexity of O(M+N) for a MxN gri...
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ISBN:
(纸本)9780889867840
In this paper, we propose a simple parallel algoritm for solving the largest empty rectangle problem in discrete domain on a rectangular pixel grid. Our algorithm has a computational complexity of O(M+N) for a MxN grid. We implement the algorithm using CUDA programming language on GPU.
This paper presents a top-down Quality-of-Service (QoS) approach to design realtime Ethernet networks for automation systems based upon tree topologies. Therefore, the parallelism of switched unicast communication is ...
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ISBN:
(纸本)088986568X
This paper presents a top-down Quality-of-Service (QoS) approach to design realtime Ethernet networks for automation systems based upon tree topologies. Therefore, the parallelism of switched unicast communication is utilized by generating an off-line schedule, which considers each port of a switch as an exclusive networking resource. We point out that the schedule can be generated independently for each switch. Starting from a given network infrastructure and QoS-requests, we present a method consisting of attribution to identify routes, specification of conflicts inside the switches, and building of a conflict-multigraph for each switch. The schedule is realized using greedy edge-coloring of the graph together with optional edge pre-sorting and re-coloring after execution of the greedy-algorithm. The method is shown for a class of special cases with unitary packet-sizes and transmission of every request in each cycle-period. Finally, some first results of this method are presented.
The Combined Input and Crosspoint Buffered (CICB) switch plays a crucial role in providing Quality of Service (QoS) in interconnection networks, which is the foundation for high-performance distributedcomputing. Cros...
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ISBN:
(纸本)9780889866386
The Combined Input and Crosspoint Buffered (CICB) switch plays a crucial role in providing Quality of Service (QoS) in interconnection networks, which is the foundation for high-performance distributedcomputing. Crosspoint buffer space is a scarce resource in CICB switches that must be utilized efficiently. Although dynamic sharing typically improves crosspoint buffer utilization, it also introduces new challenges to QoS provision in CICB switches. In this paper, we address the problem of improving crosspoint buffer utilization while providing sufficient QoS guarantees to various traffic flows in CICB switches. We propose a dynamic buffer allocation scheme that enables sharing crosspoint buffer space dynamically between flows with different QoS requirements. We also develop an analytical model for evaluating the performance of this buffer allocation scheme. Our analysis shows that if buffers are shared within a certain threshold, the dynamic buffer allocation scheme improves crosspoint buffer utilization without sacrificing delay performance. Our analysis in this paper also quantifies the tradeoff between crosspoint buffer utilization and guaranteed delay performance.
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