A difference scheme for noise removal based on four-order partial differential equations is suggested. It can approximate actual image while preserving edges and avoiding blocky effects in image processing. Numerical ...
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ISBN:
(纸本)0769529097
A difference scheme for noise removal based on four-order partial differential equations is suggested. It can approximate actual image while preserving edges and avoiding blocky effects in image processing. Numerical results are demonstrated its efficiency and the better choice of parameters.
Advances in the design, modeling and simulation of parallel processing systems provide significant research opportunities which lead to improvements on the speed, performance, fault tolerance, flexibility and cost-eff...
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ISBN:
(纸本)9780769528410
Advances in the design, modeling and simulation of parallel processing systems provide significant research opportunities which lead to improvements on the speed, performance, fault tolerance, flexibility and cost-effectiveness of distributed systems. Several parameters determine the suitability of the system architecture for a given application. However Average Routing Distance (ARD) is perhaps one of the most important parameters in performance evaluation of parallel processing systems. To this effect, all mathematical modeling and simulation of ARD and Visit Ratio for a class of parallel processing systems are presented.
Attribute reduction is a key problem in rough set theory. A novel algorithm of attribute reduction based on parallel particle swarm optimization is proposed, which can significantly reduce execution time for complex l...
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ISBN:
(纸本)9780769529097
Attribute reduction is a key problem in rough set theory. A novel algorithm of attribute reduction based on parallel particle swarm optimization is proposed, which can significantly reduce execution time for complex large-scale data sets. This algorithm constructs heuristic information from the viewpoint Of information theory, combines genetic idea and tabu operators with particle swarm optimization (PSO), redefines the updating process of particle swarm, and introduces the parallel strategy based on master-slave model with coarse grain in constructing the parallel PSO architecture. It maintains diversity of particles, which avoids the premature problem and restrains the degeneration phenomenon, and enhances the efficiency of attribute reduction. The simulation results show that this algorithm is more feasible and efficient compared with current approaches.
The distributed video coding (DVC) is a new coming video compression technology that utilizes a different computing complexity mode from the traditional video codec. As a new paradigm there are some fundamental and ha...
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ISBN:
(纸本)0769529097
The distributed video coding (DVC) is a new coming video compression technology that utilizes a different computing complexity mode from the traditional video codec. As a new paradigm there are some fundamental and hard questions in DVC that are not sufficiently addressed, for example the complexity balance between DVC encoder and decoder. This will be an important factor for some promising real time applications. In this context, this paper studies the factors which affect the decoding complexities of turbo code based DVC especially focuses on quantization, side information and turbo code bit rates. Analyzing and simulation results show that precise side information will decrease the turbo decoding complexity, large reductions in computations can be traded against relatively small increases in bit rate, and uniform quantizer possesses the advantage than the non-uniform quantizer in computation load at a expense of a little decrease in rate distortion performance.
In this paper, we propose a dynamic and reliability driven real-time fault-tolerant scheduling algorithm on heterogeneous distributed systems (DYFARS). Primary-backup copy scheme is leveraged by DYFARS to tolerate bot...
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ISBN:
(纸本)9780769529097
In this paper, we propose a dynamic and reliability driven real-time fault-tolerant scheduling algorithm on heterogeneous distributed systems (DYFARS). Primary-backup copy scheme is leveraged by DYFARS to tolerate both hardware and software failures. Most importantly, DYFARS employs reliability costs as its main objective to dynamically schedule independent, non-preemptive aperiodic tasks, therefore system reliability is enhanced without additional hardware costs. A salient difference between our DYFARS and existing scheduling approaches is that DYFARS considers backup copies in both active and passive forms;therefore, DYFARS is more flexible than the existing scheduling schemes in the literature. Finally, simulation experiments are carried out to compare DYFARS with existing similar algorithm, experiment results show that DYFARS is superior to existing algorithm regarding both Schedulability and Reliability.
Utilizing desktop grid infrastructures is challenging for parallel discrete event simulation (PDES) codes due to characteristics such as inter-process messaging, restricted execution, and overall lower concurrency tha...
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ISBN:
(纸本)9781424415595
Utilizing desktop grid infrastructures is challenging for parallel discrete event simulation (PDES) codes due to characteristics such as inter-process messaging, restricted execution, and overall lower concurrency than typical volunteer computing projects. The Aurora2 system uses an approach that simultaneously provides both replicated execution support and scalable performance of PDES applications through public resource computing. This is accomplished through a multi-threaded distributed back-end system, low overhead communications middleware, and an efficient client implementation. This paper describes the Aurora2 architecture and issues pertinent to PDES executions in a desktop grid environment that must be addressed when distributing back-end services across multiple machines. We quantify improvement over the first generation Aurora system through a comparative performance study detailing PDES programs with various scalability characteristics for execution over desktop grids.
A large number of resource locating algorithms have been proposed in peer-to-peer (P2P) networks. However, the query efficiency of most existing methods is limited to large-scale P2P networks. In this paper, we propos...
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ISBN:
(纸本)0769529097
A large number of resource locating algorithms have been proposed in peer-to-peer (P2P) networks. However, the query efficiency of most existing methods is limited to large-scale P2P networks. In this paper, we propose a new decentralized P2P architecture, by taking advantage of the heterogeneous characters of nodes to integrate the resources of stable nodes, and simplify the management of dynamic nodes based on two different types of clustering. In our proposed architecture, group-based semantic overlay network is formed by node clustering and resources of stable nodes are organized by a set of cooperative resource clustering frameworks. When a query is generated, it will be first processed in local group, and if it fails to hit the targets, it will be relayed to the resource clustering frameworks. simulation shows that this architecture can greatly reduce the search traffic in large-scale P2P networks.
To test the validity of the eigenfunction expansion method (EEM), a great deal of wave profiles calculated by EEM are compared with the corresponding results obtained by the boundary element method (BEM), which has be...
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ISBN:
(纸本)0769529097
To test the validity of the eigenfunction expansion method (EEM), a great deal of wave profiles calculated by EEM are compared with the corresponding results obtained by the boundary element method (BEM), which has been verified by many experiments. The comparisons shown that the relative errors of the maximum wave height between them are smaller than 5.5% after 10 periods when the initial wave steepness is below 0.157. However, the errors exceed 12.3% if the initial wave steepness greater than 0.198. As references, we also compared them with the linear solutions. The investigation confirmed that EEM is only valid in the transient wave propagation simulation for small or moderate wave steepness as expected. The corresponding spectrum analysis also reveals that EEM fails to capture harmonics with high wave numbers for the steep waves.
Dependable distributed embedded systems (DDES) are being deployed widely in automobile industry over the world. These systems always post rigorous requirement for timing accuracy and reliability. Both hardware and sof...
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ISBN:
(纸本)0769529097
Dependable distributed embedded systems (DDES) are being deployed widely in automobile industry over the world. These systems always post rigorous requirement for timing accuracy and reliability. Both hardware and software architecture have important effect on the system dependability. Adding or substitute for more reliable hardware could increase the system reliability moreover achieves faster system response. Apparently this would increase the manufacturing cost, while software could be a more cost-effective ways for providing support for dependable distributed embedded system development. The dependable distributed embedded system assessment platform (DDESAP) which based on vehicle control system provides testing and assessment support for various automobile dependable software. DDESAP evaluates the vehicle control hardware and operational environments. Software architectures such as time-triggered, event-triggered, hybrid-triggered and other fault tolerant mechanisms for dependable distributed embedded systems were tested on DDESAP. A vehicle dynamic model, a motorway traffic model, and a driver model were developed for DDESAP. simulation show these models comply with manufacturer and empirical data. DDESAP enables the evaluation of novel software architectures for safety-critical automobile control systems, like the fault tolerant adaptive cruise control systems (ACCS) presented.
This paper present a comparison of scheduling algorithms applied to the context of load balancing the query traffic on distributed inverted files. We implemented a number of algorithms taken from the literature. We pr...
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ISBN:
(纸本)9781595938299
This paper present a comparison of scheduling algorithms applied to the context of load balancing the query traffic on distributed inverted files. We implemented a number of algorithms taken from the literature. We propose a novel method to formulate the cost of query processing so that these algorithms can be used to schedule queries onto processors. We avoid measuring load balance at the search engine side because this can lead to imprecise evaluation. Our method is based on the simulation of a bulk-synchronous parallel computer at the broker machine side. This simulation determines an optimal way of processing the queries and provides a stable baseline upon which both the broker and search engine can tune their operation in accordance with the observed query traffic. We conclude that the simplest load balancing heuristics are good enough to achieve efficient performance. Our method can be used in practice by broker machines to schedule queries efficiently onto the cluster processors of search engines. Copyright 2007 ACM.
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