One of the difficulties inherent to conservative parallel discrete event simulation (PDES) is the need for extraction and explicit specification of the lookahead. In this paper we propose a simulator design which allo...
ISBN:
(纸本)0769516084
One of the difficulties inherent to conservative parallel discrete event simulation (PDES) is the need for extraction and explicit specification of the lookahead. In this paper we propose a simulator design which allows users to build simulation models with lookahead transparently, This is based on the cooperation between PDES experts and the users, and on the reusability, of model components. We introduce the principal design of the simulator and give the results related to its lookahead.
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.
Ten years ago, MITRE/CAASD built a realtime, Human-In-The-Loop (HITL) research laboratory. The focus of this lab is integration and human factors research for the air traffic control and aviation communities. The last...
ISBN:
(纸本)0769516084
Ten years ago, MITRE/CAASD built a realtime, Human-In-The-Loop (HITL) research laboratory. The focus of this lab is integration and human factors research for the air traffic control and aviation communities. The last ten years have been illuminating in terms of the evolution of laboratory capabilities, infrastructure, and corporate culture. This paper will describe the laboratory environment, its history and vision, and will also provide some examples of how distributedsimulation technology has been applied, and continues to evolve, in a real-world HITL simulation environment serving a broad range of research needs.
This paper threats about a work that is inserted in the context of CRUX project, which aims the conception of a complete environment for parallel programming, in development in the Course of Pos-graduation in Computer...
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ISBN:
(纸本)0769518532
This paper threats about a work that is inserted in the context of CRUX project, which aims the conception of a complete environment for parallel programming, in development in the Course of Pos-graduation in Computer Science of Santa Catarina Federal University. This paper makes an evaluation of performance of several scheduling algorithms of real time found in the bibliography, about a simulation model that represents as the processing as the communication of this multi-computer. The objective was to quantify the effect of the scheduling algorithm and other factors about some metrics of selected performance, in order to verify the applicability of CRUX in real time systems.
In this paper we discuss and compare three different causality inconsistency tracking mechanisms in support Of preemptive rollback in optimistic parallelsimulation on myrinet clusters. These mechanisms exhibit differ...
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ISBN:
(纸本)0769518532
In this paper we discuss and compare three different causality inconsistency tracking mechanisms in support Of preemptive rollback in optimistic parallelsimulation on myrinet clusters. These mechanisms exhibit different communication/processing overhead and also different effectiveness in revealing causality inconsistency of the currently executed, simulation event. By the results of an empirical study on a classical simulation benchmark we have found some trade-offs between these mechanisms, pointing out indications of application contexts for which each mechanism is expected to be well tailored.
This paper extends our previous work on formalizing event orderings using partial order set and its application in space analysis in distributedsimulation. We focus on the time an space trade-off in exploiting event ...
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ISBN:
(纸本)0769518532
This paper extends our previous work on formalizing event orderings using partial order set and its application in space analysis in distributedsimulation. We focus on the time an space trade-off in exploiting event parallelism. Event parallelism is divided into inherent (problem) parallelism, event ordering parallelism and effective event parallelism. Firstly, we analyze the performance cost of varying event ordering parallelism on memory requirement in open and closed systems. Secondly, we study the effects of interconnection topology Of a physical system on exploitable event ordering parallelism. Measurements were obtained from a time-space analyzer that we have developed.
With distributedsimulation, existing simulations, even from different disciplines, can be reused or made to interoperate. The efficiency of this technique is however not firmly established and it depends on the abili...
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ISBN:
(纸本)0769518532
With distributedsimulation, existing simulations, even from different disciplines, can be reused or made to interoperate. The efficiency of this technique is however not firmly established and it depends on the ability to satisfy a number of requirements, especially concerning simulation performance. The performance depends to a large extent on the structure and scaling of architectural components of the simulation execution platform. In this paper, we present an approach to address this problem: the design of models to capture the main characteristics of distributedsimulations, run-time infrastructures and network architectures, and the development of a tool to predict performances. This tool, which is a simulator of HLA simulations is written by using HLA and is evaluated on three test applications.
The High-Level Architecture (HLA) provides a common architecture for distributed modeling and simulation. In its original form, the HLA allows a number of simulations to be joined together into a federation using a si...
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ISBN:
(纸本)0769518532
The High-Level Architecture (HLA) provides a common architecture for distributed modeling and simulation. In its original form, the HLA allows a number of simulations to be joined together into a federation using a single run time infrastructure. Recently there has been an interest in joining multiple such federations together using a mediating unit, called an HLA "bridge." This paper presents the results of an in-depth study of the feasibility of an HLA bridge in the context of the current HLA interface specification. Problems and solutions are discussed and illustrated using particular HLA services.
Lookback is defined as the ability of a logical process to change its past locally (without involving other logical processes). Logical processes with lookback are able to process out-of-timestamp order events, enabli...
ISBN:
(纸本)0769516084
Lookback is defined as the ability of a logical process to change its past locally (without involving other logical processes). Logical processes with lookback are able to process out-of-timestamp order events, enabling new synchronization protocols for the parallel discrete event simulation. Two of such protocols, LB-GVT (LookBack-Global Virtual Time) and LB-EIT (LookBack-Earliest Input Time), are presented and their performance on the Closed Queuing Network (CQN) simulation is discussed. We also discuss in detail the relation between lookahead and lookback. Finally, we demonstrate that lookback allows conservative simulations to circumvent the speedup limit imposed by the critical path.
The Generic Runtime Infrastructure for distributedsimulation (GRIDS) has been developed to investigate modularity issues in distributedsimulation. It could be argued that although the HLA RTI is a widespread solutio...
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ISBN:
(纸本)0769518532
The Generic Runtime Infrastructure for distributedsimulation (GRIDS) has been developed to investigate modularity issues in distributedsimulation. It could be argued that although the HLA RTI is a widespread solution to distributedsimulation, it cannot include all possible services. This paper investigates an approach to extending the distributedsimulation services available in the HLA RTI. One example of this is bridging support for HLA/DIS legacy integration. This paper therefore presents GRIDS, how GRIDS can be used to provide modular service support for the HLA RTI, and a case study on legacy integration to demonstrate our approach.
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