One of the reasons why parallel programming is considered to be a difficult task is that users frequently, cannot predict the performance impact of implementation? decisions prior to program execution. this results in...
详细信息
ISBN:
(纸本)0769500595
One of the reasons why parallel programming is considered to be a difficult task is that users frequently, cannot predict the performance impact of implementation? decisions prior to program execution. this results in a cycle of incremental performance improvements based on run-time performance data. While gathering and analyzing performance data is supported by a large number of tools, typically interactive, the task of performance analysis is still too complex for. users. this article illustrates this fact based on the current analysis support on GRAY T3E. As a consequence, we are convinced that automatic analysis tools are required to identify frequently occuring and well-defined performance problems automatically! this article describes the novel design of a generic automatic performance analysis environment called KOJAK. Besides its structure we also outline the first component, EARL, a new meta-tool designed and implemented as a programmable interface to calculate more abstract metrics fr om existing trace files, and to locate complex patterns describing performance problems.
the aim of this paper is to present ar? easy and efficient method to implement alternating-line processes on current parallel computers. First we show how darn locality has an important impact on global efficiency, wh...
详细信息
ISBN:
(纸本)0769500595
the aim of this paper is to present ar? easy and efficient method to implement alternating-line processes on current parallel computers. First we show how darn locality has an important impact on global efficiency, which leads trs to the conclusion that one-dimensional decompositions are the most convenient ones Sot 2D problems. Once this is asserted a parallel algorithm is presented for the solution of the distributed tridiagonal systems along the partitioned direction. the key idea is to pipeline the simultaneous resolution of many systems of equations, riot parallelising each resolution separately. this approach presents good numerical and architectural properties, in ter ms of memory usage and data locality: and high parallel efficiencies ave obtained. For the cast of alternating-line processes, the election of the optimal decomposition is studied. the experimental results have been obtained or? a Cray T3E.
this paper discusses the NP-complete multi-constrained path problem with imprecise state information, and a distributed heuristic framework without any imprecision assumption is presented. this framework needs no link...
详细信息
ISBN:
(纸本)8955191235
this paper discusses the NP-complete multi-constrained path problem with imprecise state information, and a distributed heuristic framework without any imprecision assumption is presented. this framework needs no link state exchanging message, and employs mobile agents to search feasible paths in parallel. Two key strategies, the one to select a suitable next node and the other to choose the appropriate one from all feasible paths, are used. simulation results indicate that the presented solution is scaleable and efficient. An appropriate path selecting strategy with traffic engineering can improve network performance. And the framework can tolerate high degree of information imprecision.
the DIR net (detection-isolation-recovery net) is the main module Of a software framework for the development of embedded supercomputing applications. this framework provides a set of functional elements, collected in...
详细信息
ISBN:
(纸本)0769500595
the DIR net (detection-isolation-recovery net) is the main module Of a software framework for the development of embedded supercomputing applications. this framework provides a set of functional elements, collected in a library, to improve the dependability attributes of the applications (especially the availability). the DIR net enables these functional elements to cooperate and enhances their efficiency by controlling and co-ordinating them. As a supervisor and the main executor of the fault tolerance strategy, it is the backbone of the framework, of which the application developer is the architect. Moreover it provides an interface to which all detection and recovery tools should conform. Although the DIR net is meant to be used together within this fault tolerance framework, the adopted concepts and design decisions have a mor-e general value, and can be applied in a wide range of parallel systems.
the proceedings contain 25 papers. the topics discussed include: using request queues for enhancing the performance of operations in smart homes;flooding attacks detection in backbone traffic using power divergence;a ...
ISBN:
(纸本)9781450316262
the proceedings contain 25 papers. the topics discussed include: using request queues for enhancing the performance of operations in smart homes;flooding attacks detection in backbone traffic using power divergence;a comprehensive simulation study of low latency handoffs in mobile IPv4 for VoIP in IEEE 802.11b WLAN;decentralized indoor wireless localization using compressed sensing of signal-strength fingerprints;QoS-aware resource allocation for multimedia users in a multi-cell spectrum sharing radio network;an analytical framework for evaluating MIPv6 protocols applying transport engineering concepts;comparative evaluation of distributed physical cell identity assignment schemes for LTE-advanced systems;analytic comparison of wake-up receivers for WSNs and benefits over the wake-on radio scheme;and radio propagation in industrial wireless sensor network environments: from testbed to simulation evaluation.
simulation of large scale network scenarios is a challenging task and requires a great amount of computational power. Hence, realizing web-accessible simulation servers is a key step for the success of network simulat...
详细信息
ISBN:
(纸本)0769520367
simulation of large scale network scenarios is a challenging task and requires a great amount of computational power. Hence, realizing web-accessible simulation servers is a key step for the success of network simulation as a useful instrument in the context of network administration and capacity planning. this paper presents an XML-based description language for describing network simulation scenarios. For the proposed language, we also present an XSL translation process that can be used to automatically translate a simulation scenario into a simulation script for a well known network simulator. this work is part of a larger project, aimed at implementing a cluster-based network simulation server to be integrated in a distributed system for QoS monitoring, SLA validation and measurement-based modeling in an inter-domain environment.
the particle behavior in a parallel-hopper bell-less charging apparatus was investigated by the small scale experiment and DEM (discrete element method) simulation for mono-sized particles. the results show that the f...
详细信息
ISBN:
(纸本)9789811019265;9789811019258
the particle behavior in a parallel-hopper bell-less charging apparatus was investigated by the small scale experiment and DEM (discrete element method) simulation for mono-sized particles. the results show that the flow region in the parallel hopper can be divided into the quasi-stagnant zone, the wall shear zone, the deflecting flow zone, converging flow zone and the transitional flow zone. the velocity and the contact force chain distribution are uneven among different zones. the contact force chain distribution is asymmetric because of the asymmetric structure of the hopper. the strong force chains mainly locate in the lower part of the hopper or near the sloping wall, whereas the weak force chains are distributed over the deflected flow zone. the velocity distribution and the force chain structure are related to the flow pattern which depends on the asymmetric structure of the hopper. the burden distribution depends on the discharging sequence which is affected by flow pattern in the hopper.
the High Level Architecture (HLA) is widely used in defense applications as a common framework for modeling and simulation. the Federation Development and Execution Process (FEDEP) is a generalized process to build HL...
详细信息
ISBN:
(纸本)0769520367
the High Level Architecture (HLA) is widely used in defense applications as a common framework for modeling and simulation. the Federation Development and Execution Process (FEDEP) is a generalized process to build HLA federations from scratch. However simulation model design, implementation, testing and execution defined in the FEDEP are time consuming and expensive. the Model Construction Environment (MCE) is introduced in this paper as a web-based system to enhance the efficiency of the federation development by reusing the existing simulation Object Models (SOM) to build new Federation Object Models (FOM). To ensure the compatibility of the SOMs in a FOM, a Matching Algorithm is defined and tested. An Extensible Elements scheme is designed to help shape the characteristics of the FOM/SOMs. this study can contribute to more cost-efficient methodologies for the development and execution of simulation models.
We introduce our SimUTC toolkit, a fault-tolerant distributed systems simulation built upon the discrete event simulation package C++SIM. SimUTC has been developed in the course of our project SynUTC and targets distr...
详细信息
We introduce our SimUTC toolkit, a fault-tolerant distributed systems simulation built upon the discrete event simulation package C++SIM. SimUTC has been developed in the course of our project SynUTC and targets distributed algorithms for high-accuracy fault-tolerant clock synchronization. this application domain requires detailed simulation models for network transmission and local clock devices, fault-injection capabilities, flexible system configuration facilities, and customized data capture and analysis tools. We explain how SimUTC addresses those issues and provide a few samples of simulation results gathered from the evaluation of the well-known Fault-Tolerant Average clock synchronization algorithm.
distributed network storage systems regularly make use of object replication to achieve sufficient levels of reliability under network churn. To maintain reliability, a repair mechanism is employed, which replaces des...
详细信息
暂无评论