An Analysis of Migration Strategies in Island-Based Multimemetic Algorithms

Rafael Nogueras & Carlos Cotta

Memes are patterns-based rewriting rules [CàA]: •  C, A ∈Σr with Σ={0,1,#}, r∈Ν

•  ‘#’ represents a wildcard symbol

Meme à Unit of imitation

Encoded in computational representations (meme↔gene)

MMA

Very important

Meme Propagation

more complex

Replace-worst

Replace-random

Population Entropy

Meme Success Rate

m ς ωS ωR

Syn asyn

best rand

probabilistic diverse-gene diverse-meme

random-immigrants

replace-worst

replace-random

ωS

ωR

TRAP-128

HIFF-128

HXOR-128

SAT-128

µ=128 ni∈1,2,4,8 UniRing

m=1, ς=20

Friedman & Quade Tests

Holm Test

•  Importance of migrant selection and migrant replacement •  Replacement strategy has less impact than selection strategy •  Strategies based on memetic diversity are better than genetic counterparts. •  Probabilistic model is competitive with some migrations operators Future work: •  More complex probabilistic model •  Other self-adaptative memetic models

Let G=00010011, and let a meme be 01#à1#0:

PPSN 2014 Ljubljana, Slovenia

Memes Search Process

conduct Self-

adaptation ωR

ωS ↑↑

↓↓

MEME

Self-Adaptation in Search Process