We present a dynamic load balancing algorithm for parallel discrete event simulation of spatially explicit problems. In our simulations, the space is discretized and divided into subareas, each of which is simulated b...
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We present a dynamic load balancing algorithm for parallel discrete event simulation of spatially explicit problems. In our simulations, the space is discretized and divided into subareas, each of which is simulated by a logical process (LP). Load predictions are done based on the future events that are scheduled for a given LP. The information about the load of the processes is gathered and distributed during the Global Virtual Time calculation. Each LP calculates the new load distribution of the system. The load is then balanced by moving spatial data between neighboring LPs in one round of communications. In our problems, the LPs should be described as being elements of a ring from the point of view of communication. Due to the spatial characteristics, the load can be migrated only between neighboring LPs. We present an algorithm that performs the load balancing in a ring and minimizes the maximum after-balance load.
The paper presents an analytical model for evaluating the performance of Time Warp simulators. The proposed model is formalized based on two important time components in parallel and distributed processing: computatio...
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ISBN:
(纸本)0818684577
The paper presents an analytical model for evaluating the performance of Time Warp simulators. The proposed model is formalized based on two important time components in parallel and distributed processing: computation time and communication time. The communication time is modeled by buffer access time and message transmission time. Logical processes of the Time Warp simulation, and the processors executing them are assumed to be homogeneous. Performance metrics such as rollback probability, rollback distance, elapsed time and Time Warp efficiency are derived. More importantly, we also analyze the impact of cascading rollback waves on the overall Time Warp performance. By rendering the deviation in state numbers of sender-receiver pairs, we investigate the performance of throttled Time Warp scheme. Our analytical model shows that the deviation in state numbers and the communication delay have a profound impact on Time Warp efficiency. The performance model has been validated against implementation results obtained on a Fujitsu AP3000 parallel computer. The analytical framework can be readily used to estimate performance before the Time Warp simulator is implemented.
In previous papers, we have described a reduction model for computing near-perfect state information (NPSI) in support of adaptive synchronization in a parallel discrete event simulation (S. Srinivasan et al., 1995; 1...
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In previous papers, we have described a reduction model for computing near-perfect state information (NPSI) in support of adaptive synchronization in a parallel discrete event simulation (S. Srinivasan et al., 1995; 1995). We report on an implementation of this model on a popular high performance computing platform-a network of workstations-without the use of special purpose hardware. The specific platform is a set of Pentium Pro PCs, interconnected by Myrinet-a Gbps network. We describe the reduction model and its use in our Elastic Time Algorithm. We summarize our design, described in an earlier paper and focus on the details of the implementation of this design. We present performance results that indicate that NPSI is feasible for simulations with medium to large event granularity.
The paper presents an overview of the PARASOL interface and its potential impact on facilitating transfer of technology from the academic researchers to the industrial end users. The PARASOL project aims at developing...
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The paper presents an overview of the PARASOL interface and its potential impact on facilitating transfer of technology from the academic researchers to the industrial end users. The PARASOL project aims at developing scalable direct and iterative solvers and testing them on real problems with respect to applicability and robustness in the industrial applications such as linear structural analysis (MSC/NASTRAN and SESAM), simulation of nonlinear forming and deformation processes (ARC3D and INDEED), and modeling of incompressible viscous flow (POLYFLOW).
Mastering increasing complexity of civil airborne equipment systems needs new architectural concepts mainly based on modular design, generic resources and multiplexed communication buses. These new architectures, such...
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Mastering increasing complexity of civil airborne equipment systems needs new architectural concepts mainly based on modular design, generic resources and multiplexed communication buses. These new architectures, such as Integrated Modular Avionics (IMA) architecture, rely on the definition of standardized hardware and software. However, the development of an IMA architecture requires new tools enabling platform designer, applications developer and system integrator to describe and evaluate different implementation choices. This paper, identifies and characterizes different levels of needed models in order to catch essential information for performance evaluation of avionics applications integrated in IMA. Four model levels are proposed: application model, architectural model, execution model and allocation model. These different modeling levels allow the generation of a simulation model of avionics systems allocated on an IMA platform.
Data distribution management (DDM) is concerned with the problem of efficiently distributing state information among the entities in a distributedsimulation. While heavily studied in the DIS community for training ap...
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Data distribution management (DDM) is concerned with the problem of efficiently distributing state information among the entities in a distributedsimulation. While heavily studied in the DIS community for training applications using real time synchronization, this problem has received considerably less attention for logical time simulations, and little performance data has appeared in this regard. The paper is concerned with evaluating the performance of a logical time synchronized DDM mechanism. A DDM algorithm based on the services specified in the DoD High Level Architecture (HLA) using routing spaces is described, as well as its implementation on a network of workstations environment. Performance measurements indicate that the time overhead to provide correct logical time synchronization of the DDM mechanisms is small, relative to network communication overheads, suggesting that logical time synchronized DDM mechanisms can perform as efficiently as real time synchronized mechanisms in networked workstation environments.
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