Time-parallelsimulation offers the potential of massive parallelization of a simulation application, due to the amount of achievable parallelism not being restricted by the decomposability of the state space of a sim...
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ISBN:
(纸本)0769521118
Time-parallelsimulation offers the potential of massive parallelization of a simulation application, due to the amount of achievable parallelism not being restricted by the decomposability of the state space of a simulation model. Unfortunately, the potential speedup of a time-parallelsimulation highly depends on the ability to match final and initial states of adjacent time intervals. Depending on the properties of the underlying simulation model, it might be feasible to accept a simulation iteration, even if the states of adjacent time intervals do not match exactly. This leads to the concept of approximative state matching in time-parallelsimulation, which is introduced in this paper Experiments with a prototypical implementation of a simple simulation model show encouraging results in terms of simulation speedup and introduced error.
In this paper, the relationship between the computational models of Object-Oriented Rewriting and parallel Discrete-Event simulation models is explored. A discrete-event simulation program in which several objects int...
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ISBN:
(纸本)0818683325
In this paper, the relationship between the computational models of Object-Oriented Rewriting and parallel Discrete-Event simulation models is explored. A discrete-event simulation program in which several objects interact with each other by exchanging messages may have a high degree of concurrency (which can be exploited using optimistic or conservative parallelsimulation methods). We report on some observations on using Rewriting Logic in the field of parallel Discrete Event simulations, and investigate how parallelsimulation applications can be expressed using Object-Oriented Rewriting.
As an alternative to spatial parallelization of simulation models, time-parallelsimulation offers the potential for massive parallelism with a high level of independence between the parallel processes. Unfortunately,...
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ISBN:
(纸本)0769523838
As an alternative to spatial parallelization of simulation models, time-parallelsimulation offers the potential for massive parallelism with a high level of independence between the parallel processes. Unfortunately, due to inherent problems, the applicability of time-parallelsimulation is restricted. Therefore, it has been proposed recently, to use approximation with time-parallelsimulation in order to facilitate its application and to extend the class of models suitable for time-parallelsimulation. As a proof-of-concept, this work shows how approximate temporal parallelization can be applied to the simulation of road traffic. Traffic simulation is used extensively in transportation research for various purposes, e.g. analysis of traffic phenomena, traffic forecast, and optimization of traffic flow. Depending on the level of fidelity, a traffic model exhibits a state space of moderate to high complexity. This paper is intended to discuss the basic properties of time-parallel traffic simulation and to examine its feasibility. Experiments with a sequential microscopic traffic simulator that emulates important aspects of a corresponding time-parallel simulator suggest this feasibility.
A study is presented in applying optimistic parallel discrete event simulation techniques using reverse execution to perform instruction-level simulations of distributed memory multi-processor systems. A static progra...
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ISBN:
(纸本)9780769528984
A study is presented in applying optimistic parallel discrete event simulation techniques using reverse execution to perform instruction-level simulations of distributed memory multi-processor systems. A static program analysis approach is described to optimize pre-processed simulated applications in order to remove certain overheads associated with forward event execution and to enable reversible execution. Reverse execution of floating point operations are also considered. Preliminary performance measurements are presented indicating this approach offers promise in speeding up parallel multi-processor simulations.
Performance analysis of distributed systems may be performed on different levels of abstraction. An accurate but time-consuming method is the construction of a simulation model which includes the different subsystems,...
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ISBN:
(纸本)0818680970
Performance analysis of distributed systems may be performed on different levels of abstraction. An accurate but time-consuming method is the construction of a simulation model which includes the different subsystems, the communication system, and the load profile. In particular, this approach seems to be very powerful for real-time systems because of the inherent possibility of precise calculations of delays and processing times. A VHDL-based approach is presented which supports the performance analysis of mixed discrete-continuous, distributed systems.
This paper introduces a hybrid Associative memory/SIMD parallel processor, APPLES, which has been specifically designed for logic simulation. Its reviews the computational structure which permits parallel execution of...
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ISBN:
(纸本)0769500595
This paper introduces a hybrid Associative memory/SIMD parallel processor, APPLES, which has been specifically designed for logic simulation. Its reviews the computational structure which permits parallel execution of logic gate evaluations in memory. This facilitates fine grain execution on a massive scale of the basic tasks inherent in VLSI logic simulation. Furthermore, unlike of her SIMD approaches the simulation is not limited to a unit delay model, complex delays such as inertial delays are permissible. The processor has been implemented in Verilog and assessed using ISCAS-85 benchmarks. Gate evaluation is executed in constant time, whereas updating fan-out lists expands with circuit size. However, the APPLES architecture enables this latter task to be parallelised subject to various system parameters. The most important constraint is identified as the fan-out memory access time relative to the scan rate of the associative memory.
Running a large-scale distributedsimulation may need a large amount of computing resources at geographically different locations. These resources may be from different organizations. The simulation may run for a long...
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ISBN:
(纸本)0769518532
Running a large-scale distributedsimulation may need a large amount of computing resources at geographically different locations. These resources may be from different organizations. The simulation may run for a long period of time and the availability and the amount of computing resources available may change during the course of the simulation execution. Therefore, coordinating and managing the resources for distributedsimulation to complete the simulation efficiently and effectively is a, critical issue. This paper describes a load management system for HLA-based distributedsimulation. The system is constructed on top of a Grid Computing environment supported by Globus. The overall structure of the system is presented in the paper and how the system saves and restores a federate is also discussed in detail.
The master/worker (MW) paradigm can be used to implement parallel discrete event simulations (PDES) on metacomputing systems. MW PDES applications incur overheads not found in conventional PDES executions executing on...
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ISBN:
(纸本)9780769537139
The master/worker (MW) paradigm can be used to implement parallel discrete event simulations (PDES) on metacomputing systems. MW PDES applications incur overheads not found in conventional PDES executions executing on tightly coupled machines. We introduce four techniques for reducing these overheads on public resource and desktop grid infrastructures Work unit caching, pipelined state updates, expedited message delivery, and adaptive work unit scheduling mechanisms are described that provide significant reduction in overall overhead when used in tandem. We present performance results showing that an optimized MW PDES system can exhibit performance comparable to a traditional PDES system for a queueing network and a particle physics simulation.
The parallel (and distributed) Discrete Event simulation (PADS) community - over it's more than 20 years of existence has achieved remarkable results in getting the execution of simulations of discrete event syste...
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ISBN:
(纸本)0769521118
The parallel (and distributed) Discrete Event simulation (PADS) community - over it's more than 20 years of existence has achieved remarkable results in getting the execution of simulations of discrete event systems faster, involving multiple, logically and/or physically dispersed, communicating computational resources. A solid, mature and empirically approved body of foundational concepts, models, systems, methods and algorithms are at hand and well documented in more than 50.000 pages of research papers. PADS simulation engines, model and software libraries, and operating systems have proven feasibility and applicability of these results in solving real world problems. Despite the (healthy) self-criticism of it's proponents ("Will the field survive?"), PADS was - and is - a success! With this talk we aim at a prospect for the challenges posed by the emerging new models of computational and communication, the evolving new paradigms of interaction and coordination, the new styles of system design, and even the availability of new technologies, for which - in my opinion - no other community qualifies better than the PADS community.
We propose a new simulation method, called interval branching, which aims to facilitate efficient simulation studies of systems that involve temporal uncertainty. The method uses interval timestamps for events and exp...
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ISBN:
(纸本)9780769531595
We propose a new simulation method, called interval branching, which aims to facilitate efficient simulation studies of systems that involve temporal uncertainty. The method uses interval timestamps for events and explores different execution orders of overlapping events by branching the simulation. We first present a sequential version of interval branching, and then extend it to parallelsimulation using the logical process paradigm. The parallel interval branching algorithm uses the logical-process cloning technique for efficient computation of branches. Our preliminary experiments show its potential as an efficient method for discrete-event simulation studies.
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