Changes between Version 1 and Version 2 of Documentation/Reference/Evolution Strategy

Timestamp:

06/02/10 14:12:09 (14 years ago)

Author:

mkofler

Comment:

--

Documentation/Reference/Evolution Strategy

@@ -1 +1 @@
 = Evolution Strategy =
+At about the same time genetic algorithms were developed, evolution strategies (ES) appeared in first publications. Originally, they differed from the genetic algorithm such that the main operator responsible for the creation of solutions is the mutation operator. ''Ingo Rechenberg'' and ''Hans-Paul Schwefel'' introduced several basic variants of ES before adopting more complex solution manipulation concepts, such as recombination, to broaden the applicability of the evolution strategy (Rechenberg 1973).
+
+'''Variants:''' 
+The first variant is the simple (1+1)-ES where a mutant was created from a given parent which replaced the parent only if it was better. It was shown that such a simple strategy coupled with a more intelligent adaption of the mutation strength allowed the ES to converge quickly to a good solution. Further evolved variants make use of a population, by extending the (1+1)-ES to a generic (μ+λ)-ES and also include generational replacement, called “comma replacement”. Additionally, recombination was introduced into the algorithm, as well as a way to self-adapt the mutation strength during the progress of the search.
 
 '''Algorithm Parameters:'''
@@ -16 +20 @@
 || !StrategyParameterCrossover || The operator that recombines the strategy parameters. ||
 || !StrategyParameterManipulator || The operator that manipulates the strategy parameters. ||
+
+'''References:'''
+* Rechenberg, I. 1973. Evolutionsstrategie - Optimierung technischer Systeme nach Prinzipien der biologischen Evolution. Frommann-Holzboog.