Virtual Time Integration of Emulation and Parallel Simulation

2012 ◽  
Author(s):  
Dong Jin ◽  
Yuhao Zheng ◽  
Huaiyu Zhu ◽  
David M. Nicol ◽  
Lenhard Winterrowd
Keyword(s):  
Time Integration ◽  
Parallel Simulation ◽  
Virtual Time

scholarly journals Performance limitations of parallel simulations

1998 ◽  
Vol 11 (3) ◽  
pp. 397-409 ◽  
Author(s):  
Liang Chen ◽  
Richard F. Serfozo
Keyword(s):  
Real Time ◽  
Numerical Experiments ◽  
Distributed Processing ◽  
Upper Bounds ◽  
Parallel Simulation ◽  
Time Transformation ◽  
Parallel Simulations ◽  
Optimistic Protocols ◽  
Virtual Time ◽  
Insight Into

This study shows how the performance of a parallel simulation may be affected by the structure of the system being simulated. We consider a wide class of “linearly synchronous” simulations consisting of asynchronous and synchronous parallel simulations (or other distributed-processing systems), with conservative or optimistic protocols, in which the differences in the virtual times of the logical processes being simulated in real time t are of the order o(t) as t tends to infinity. Using a random time transformation idea, we show how a simulation's processing rate in real time is related to the throughput rates in virtual time of the system being simulated. This relation is the basis for establishing upper bounds on simulation processing rates. The bounds for the rates are tight and are close to the actual rates as numerical experiments indicate. We use the bounds to determine the maximum number of processors that a simulation can effectively use. The bounds also give insight into efficient assignment of processors to the logical processes in a simulation.

Advances and Challenges in Time-Integration of PDE's

2003 ◽  
Author(s):  
David Gottlieb ◽  
Jan Hesthaven
Keyword(s):  
Time Integration

scholarly journals A Fully Implicit Finite Volume Scheme for a Seawater Intrusion Problem in Coastal Aquifers

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1639
Author(s):  
Abdelkrim Aharmouch ◽  
Brahim Amaziane ◽  
Mustapha El Ossmani ◽  
Khadija Talali
Keyword(s):  
Finite Volume ◽  
Coastal Aquifers ◽  
Nonlinear Partial Differential Equations ◽  
Time Integration ◽  
Mass Conservation ◽  
Coupled System ◽  
Finite Volume Scheme ◽  
Time Step ◽  
Volume Scheme ◽  
Fully Implicit

We present a numerical framework for efficiently simulating seawater flow in coastal aquifers using a finite volume method. The mathematical model consists of coupled and nonlinear partial differential equations. Difficulties arise from the nonlinear structure of the system and the complexity of natural fields, which results in complex aquifer geometries and heterogeneity in the hydraulic parameters. When numerically solving such a model, due to the mentioned feature, attempts to explicitly perform the time integration result in an excessively restricted stability condition on time step. An implicit method, which calculates the flow dynamics at each time step, is needed to overcome the stability problem of the time integration and mass conservation. A fully implicit finite volume scheme is developed to discretize the coupled system that allows the use of much longer time steps than explicit schemes. We have developed and implemented this scheme in a new module in the context of the open source platform DuMu X . The accuracy and effectiveness of this new module are demonstrated through numerical investigation for simulating the displacement of the sharp interface between saltwater and freshwater in groundwater flow. Lastly, numerical results of a realistic test case are presented to prove the efficiency and the performance of the method.

Restructuring a parallel simulation to improve cache behavior in a shared-memory multiprocessor

1993 ◽  
Vol 23 (1) ◽  
pp. 159-162
Author(s):  
David R. Cheriton ◽  
Hendrik A. Goosen ◽  
Hugh Holbrook ◽  
Philip Machanick
Keyword(s):  
Shared Memory ◽  
Parallel Simulation ◽  
Shared Memory Multiprocessor
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