User:Lsalgo/Synchronous Relaxation for Parallel Discrete Event Simulations

Synchronous Relaxation for Parallel Discrete Event Simulations is a method to perform a discrete event simulation on a parallel computer. The Synchronous Relaxation (SR) method is general in that it makes no use of specifics of the simulated system and it is computationally efficient in that it typically delivers the speedup of the order of $N/\log(N)$, where ${N}$ is the number of processors in the parallel computer.

When the SR is applicable

A model of a multi-component dynamic system with discrete events might be suitable for a SR simulation. The time is assumed to be continuous in such a model. The system state can change only instantaneosly and only by changing the state of a component. This is identified as a discrete event that occurs in that component. The event may affect future events in this and other components. Examples of such models are numerous: telephone networks models, models of Ising spins, models of collision detection of particles, to name a few.

In a circuit-switched telephone network, an event is a change of the occupancy level of a trunk (channel), when a phone call is allocated to this trunk. Allocation status of a trunk affects future allocations of this and other trunks via the logic of the allocation algorithm. The comparative behavior of various allocation algorithms is a subject of the study in this simulation, where both, the SR method of parallel simulations and the term "Synchronous Relaxation" itself in the application to parallel simulations, were originally introduced .

A system of Ising spins is a set of atoms placed in space, so that each atom has a few neighbors. Each atom has a state, called "spin", which take on two values, $1$ and $-1$. Atoms change spins at asynchronous random times. When an atom changes its spin, the new spin is a function of the existing spins of itself and its neighbors.

External links

• example.com