The proceedings contain 7 papers. The topics discussed include: high level architecture for simulation;DEVS formalism as a framework for advanced distributedsimulation;simulation of fine-grained parallel algorithms w...
ISBN:
(纸本)0818677732
The proceedings contain 7 papers. The topics discussed include: high level architecture for simulation;DEVS formalism as a framework for advanced distributedsimulation;simulation of fine-grained parallel algorithms with the ALT (animating language tools) system;event synchronization in multi-user virtual reality environments;feedback control in time warp synchronized parallel simulators;COVERS 3.0 - an object-oriented environment for modeling, simulation, and analysis of real-time concurrent systems;design and simulations of cellular neural-like associative memory;and design of high-speed parallel arithmetic algorithms and architectures.
In traditional optimistic distributedsimulation protocols, a logical process (LP) receiving a straggler rolls back and sends out anti-messages. Receiver of an anti-message may also roll back and send out more anti-me...
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In traditional optimistic distributedsimulation protocols, a logical process (LP) receiving a straggler rolls back and sends out anti-messages. Receiver of an anti-message may also roll back and send out more anti-messages. So a single straggler may result in a large number of anti-messages and multiple rollbacks of some LPs. In our protocol, an LP receiving a straggler broadcasts its rollback. On receiving this announcement, other LPs may roll back but they do not announce their rollbacks. So each LP rolls back at most once in response to each straggler. Anti-messages are not used. This eliminates the need for output queues and results in simple memory management. It also eliminates the problem of cascading rollbacks and echoing, and results in faster simulation. All this is achieved by a scheme for maintaining transitive dependency information. The cost incurred includes the tagging of each message with extra dependency information and the increased processing time upon receiving a message. We also present the similarities between the two areas of distributedsimulation and distributed recovery. We show how the solutions for one area can be applied to the other area.
Compared to highly optimized optimistic simulators which use local event queues for individual processors on a shared-memory computer, we demonstrate that employing a single global event queue drastically reduces the ...
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Compared to highly optimized optimistic simulators which use local event queues for individual processors on a shared-memory computer, we demonstrate that employing a single global event queue drastically reduces the number of rollbacks, brings down the storage requirements, and achieves superior load balance. On a bus-based Silicon Graphics multiprocessor, these virtues consistently translated into faster execution times and higher speedups on those synthetic networks of medium- to coarse-grained logical processes which were ridden with rollbacks and load imbalance on local-queue-based simulators. A dynamic randomization-based load distribution scheme for local-event-queue simulators is also shown to be an effective improvement.
The proceedings contain 16 papers. The topics discussed include: distributedparallel computing using windows desktop systems;a load balancing tool for distributedparallel loops;a diskless checkpointing algorithm for...
ISBN:
(纸本)0769519849
The proceedings contain 16 papers. The topics discussed include: distributedparallel computing using windows desktop systems;a load balancing tool for distributedparallel loops;a diskless checkpointing algorithm for super-scale architectures applied to the fast Fourier transform;dynamic replication to improve input/output scalability of genomic alignment;towards a grid-based architecture for traditional Chinese medicine;towards a grid-based architecture for traditional Chinese medicine;issues in runtime algorithm selection for grid environments;resource co-allocation for parallel tasks in computational grids;scalable state replication with weak consistency;runtime support for changing the communication model in large scale applications;impact of admission and cache replacement policies on response times of jobs on data grids;and distributing simulation work based on component activity: a new approach to partitioning hierarchical DEVS models.
In a distributedsimulation, simulation components of various types are executed at geographically different locations, forming a simulation federation to create a common virtual environment. Under the High Level Arch...
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In a distributedsimulation, simulation components of various types are executed at geographically different locations, forming a simulation federation to create a common virtual environment. Under the High Level Architecture (HLA), information that will be produced and consumed by a simulation component is defined in its object model, and how that information is produced and consumed is well encapsulated inside the simulation component's implementation. However, in the current implementation of the HLA's Runtime Infrastructure (RTI), information hiding between groups of simulation components in a simulation federation is not addressed. In this paper, we discuss how hierarchical federations architectures can be used to tackle this problem. The hierarchical federations architecture adopted in this paper differs from the existing architectures in that it is based on a hybrid approach for inter-operability between simulation federations. To demonstrate the information hiding using the architecture, a distributed semiconductor supply-chain simulation is also described in the paper.
Several mathematical and algorithmic problems that have arisen in discrete event simulations of large systems are described. The simulated systems belong to the areas of computational physics, queueing networks, and e...
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ISBN:
(纸本)1565550552
Several mathematical and algorithmic problems that have arisen in discrete event simulations of large systems are described. The simulated systems belong to the areas of computational physics, queueing networks, and econometric models.
One of the promises of parallelized discrete-event simulation is that it might provide significant speedups over sequential simulation. In reality, high performance cannot be achieved unless the system is fine-tuned t...
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One of the promises of parallelized discrete-event simulation is that it might provide significant speedups over sequential simulation. In reality, high performance cannot be achieved unless the system is fine-tuned to balance computation, communication, and synchronization requirements. In this paper, we discuss our experiments in automated load balancing using the SPEEDES simulation framework. Specifically, we examine three mapping algorithms that use run-time measurements. Using simulation models of queuing networks and the National Airspace System, we investigate (i) the use of run-time data to guide mapping, (ii) the utility of considering communication costs in a mapping algorithm, (iii) the degree to which computational 'hot-spots' ought to be broken up in the linearization, and (iv) the relative execution costs of the different algorithms. We compare the performance of the three algorithms using results from the Intel Paragon.
The paper presents an approach for achieving better performance of Monte Carlo simulation by implementing the process in a distributed computing environment. The simulation process is analyzed and sub processes, suita...
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ISBN:
(纸本)9789549641523
The paper presents an approach for achieving better performance of Monte Carlo simulation by implementing the process in a distributed computing environment. The simulation process is analyzed and sub processes, suitable for parallel execution are defined. The proposed approach is demonstrated by applying Monte Carlo simulation for evaluating the market risk of a financial position in an experimental distributed computing environment. Comparison data, obtained by carrying out the same simulation in an environment with one computer and in distributed environment, are presented and analyzed.
Packet-level discrete-event network simulators use an event to model the movement of each packet in the network. This results in accurate models, but requires that many events are executed to simulate large, high band...
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ISBN:
(纸本)0769519709
Packet-level discrete-event network simulators use an event to model the movement of each packet in the network. This results in accurate models, but requires that many events are executed to simulate large, high bandwidth networks. Fluid-based network simulators abstract the model to consider only changes in rates of traffic flows. This can result in large performance advantages, though information about the individual packets is lost making this approach inappropriate for many simulation and emulation studies. This paper presents a hybrid model in which packet flows and fluid flows coexist and interact. This enables studies to be performed with background traffic modeled using fluid flows and foreground traffic modeled at the packet level. Results presented show up to 20 times speedup using this technique. Accuracy is within 4% for latency and 15% for jitter in many cases.
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