Title
Mixed integer evolution strategies for parameter optimization.
Abstract
Evolution strategies (ESs) are powerful probabilistic search and optimization algorithms gleaned from biological evolution theory. They have been successfully applied to a wide range of real world applications. The modern ESs are mainly designed for solving continuous parameter optimization problems. Their ability to adapt the parameters of the multivariate normal distribution used for mutation during the optimization run makes them well suited for this domain. In this article we describe and study mixed integer evolution strategies (MIES), which are natural extensions of ES for mixed integer optimization problems. MIES can deal with parameter vectors consisting not only of continuous variables but also with nominal discrete and integer variables. Following the design principles of the canonical evolution strategies, they use specialized mutation operators tailored for the aforementioned mixed parameter classes. For each type of variable, the choice of mutation operators is governed by a natural metric for this variable type, maximal entropy, and symmetry considerations. All distributions used for mutation can be controlled in their shape by means of scaling parameters, allowing self-adaptation to be implemented. After introducing and motivating the conceptual design of the MIES, we study the optimality of the self-adaptation of step sizes and mutation rates on a generalized (weighted) sphere model. Moreover, we prove global convergence of the MIES on a very general class of problems. The remainder of the article is devoted to performance studies on artificial landscapes (barrier functions and mixed integer NK landscapes), and a case study in the optimization of medical image analysis systems. In addition, we show that with proper constraint handling techniques, MIES can also be applied to classical mixed integer nonlinear programming problems.
Year
DOI
Venue
2013
10.1162/EVCO_a_00059
Evolutionary Computation
Keywords
Field
DocType
mixed integer,mixed integer evolution strategies,integer variable,nk landscapes,classical mixed integer nonlinear,continuous parameter optimization problem,mixed integer optimization problem,mixed integer evolution strategy,aforementioned mixed parameter class,optimization algorithm,evolution strategies,mutation rate,mutation operator
Convergence (routing),Integer,Conceptual design,Mathematical optimization,Remainder,Multivariate normal distribution,Probabilistic logic,Scaling,Optimization problem,Mathematics
Journal
Volume
Issue
ISSN
21
1
1530-9304
Citations 
PageRank 
References 
15
0.82
19
Authors
7
Name
Order
Citations
PageRank
Rui Li1788.10
Michael T. M. Emmerich224722.74
Jeroen Eggermont321117.08
Thomas Bäck462986.94
Martin Schütz5150.82
Jouke Dijkstra612616.92
J. H. C. Reiber71007.24