The paper investigates some important transport layer algorithms for wireless sensor networks. On the basis of the single-path-based distributed TCP caching, which work badly when some node on the path be down, adopt ...
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ISBN:
(纸本)0769529097
The paper investigates some important transport layer algorithms for wireless sensor networks. On the basis of the single-path-based distributed TCP caching, which work badly when some node on the path be down, adopt multi-path routing on the network layer and distributed TCP caching on the transport layer to enhance transport reliability. From the simulation results, it improves overall performance in term of end-to-end transport delay comparing with the original DTC algorithm and loads are distributed among the intermediate nodes. And then address some open issues as the research prospects.
As High Level Architecture (HLA) standard widely used in underwater warfare simulation applications, it is imperative that we should meet the need for the adaptation to the changing warfare requirements and improve de...
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ISBN:
(纸本)9780769529097
As High Level Architecture (HLA) standard widely used in underwater warfare simulation applications, it is imperative that we should meet the need for the adaptation to the changing warfare requirements and improve development efficiency and reusability of simulation software, especially when developing a federate, known as a node in HLA-based distributedsimulation. To address this problem, we present a dynamic reconfigurable adaptive software architecture for federate in this paper. The architecture has capability of self-adaptation to simulation requirements, and separates function realization from configuration control. It is composed of four layers, interface communication, requirement management, adaptation management and function realization. In this architecture, we partition the federate into several functional parts in terms of a definite granularity with Component-Based Software Development (CBSD) methodology. The architecture can adjust dynamically the configuration of federate to the new requirements while the simulation requirements change. Finally, we take a general sonar federate as an example to illustrate the presented architecture's support for adaptation.
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.
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