[Beowulf] help on island model

[Eric Thibodeau]

I happen to be working on just this subject ;)

	Island model can be more than one thing, it depends on your implementation. 
>From your description, you seem to be implementing a "multiple-deem" approach 
while retaining the same GA parameters across these islands. David A. Van 
Veldhuizen addresses the parallelisation issues in his document entitled 
"Considerations in Engineering Parallel Multiobjective Evolutionary 
Algorithms" http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1197689

Even though his article is oriented towards MOGAs, most if not all issues 
brought up in his article also apply to GAs. To give you an idea, here are 
four points brought up in his article specifically about island model:

  Four basic island pMOEA variants are seen to exist, each with
appropriate migration operators.
  1) All islands execute identical MOEAs/parameters (homo-
     geneous).
  2) All islands execute different MOEAs/parameters (hetero-
     geneous).
  3) Each island evaluates different objective function subsets.
  4) Each island represents a different region of the genotype
     or phenotype domains.

	My masters is actually geared at trying to "answer" or "reply" to some of the 
unanswered questions brought up in this same article (providing quantitative 
results with a clearly defined/detailed environment specification as well as 
some sort of recipe for parallelising a specifically given MOGA).

I hope this reference helps!

Eric

Le Dimanche 5 Mars 2006 03:30, purnima a écrit :
> hi,
>       I've to implement island model genetic algorithm using MPI. the 
problem is I've already implemented a parallel Genetic Algorithm using MPI 
where i divide population into subpopulations and distribute it 2 all the 
processors, and each processors performs sequential GA on its subpopulation 
after some iteration these processors migrates its best chromosome toe ach 
other and again proceed.
>  
>  My problem is that i dnt understand what exactly is island model? what 
island represents??  how shud i implement it.. 
>  Plz reply soon..
>  thanx
>  
> 			
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Eric Thibodeau
Neural Bucket Solutions Inc.
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