Workshop on Parameter Setting in Genetic and
Evolutionary Algorithms (PSGEA 2005)

Genetic and Evolutionary Computation COnference (GECCO 2005)

June, 25-29, 2005
Washigton, D.C. USA
Scope ]   [ Participation ]   [ Important Dates ]   [ Attendance ]   [ Program Schedule ]   [ Chairs ]   [ Program Committee ]   [ Talk Abstracts ]
  • 05/12/2004: The schedule for the workshop is available. See Program Schedule for details.

  • 05/11/2004: Invited Talk by Tian-Li Yu on Online Population Size Adjusting Using Noise and Substructural Measurements. See Talk Abstracts for details.

  • 05/11/2004: Invited Talk by Kumara Sastry on Population Sizing for Genetic Programming Based Upon Decision Making. See Talk Abstracts for details.

   Scope
One of the main difficulties that a user faces when applying a GEA is on deciding on an appropriate set of parameter values. Before running the algorithm, the user has to specify a number of parameters, such as population size, selection rate, crossover probability, and mutation probability. Over the years, there has been a variety of research studies with the purpose of understanding parameter interactions, as well as different approaches to automate parameter setting in GEAs. In this workshop we would like to have an open discussion on the following topics:

- Interactions among GEA parameters,
- Behavior of one (or more) specific GEA parameter,
- Practical guidelines for parameter configuration and trade-off in GEAs,
- Parameter setting in GEAs for real-world problems,
- Deterministic and adaptive parameter-less techniques for GEAs,
- Self-adaptive parameter-less techniques for GEAs,
- Benefits and drawbacks of the different approaches to automate parameter setting in GEAs.

The length of the workshop is 4 hours. The workshop will start with an introduction by the organizers. This will be followed by about 5-7 presentations. The workshop will finish with a panel discussion.

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   Participation
Presentations will be selected according to the submitted papers (with a maximum length of 12 pages) which will be reviewed by at least two members of the international program committee. All accepted papers will be included in the workshop proceedings that will be available at GECCO-2005 check in. Papers should be submitted in electronic PDF format following the GECCO paper format. When submitting your paper please use the following subject: "PSGEA submission".

Extended versions of selected papers presented at the workshop will be published in a book entitled "Parameter Setting in Genetic and Evolutionary Algorithms", which will be part of the new series Studies in Computational Intelligence by Springer.

If you have any question please contact the workshop organizers.

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   Importante Dates
The following dates are preliminary and are subject to change:

Paper submission deadline:April 01, 2005
Decisions will be mailed by:April 20, 2005
Submissions of camera-ready papers:April 26, 2005
Workshop day:June 25, 2005

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   Attendance
Attendance to the workshop is open to all GECCO attendees. We particularly welcome researchers who have been working on the topic of automating parameter settings in GEAs, and practitioners who want to apply GEAs for problem solving but that are often confused with the nuts and bolts of parameter settings.

We are looking forward to your participation!

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   Program Schedule

8:30 -- 8:45
Introduction by the Workshop Organizers

8:45 -- 9:30
Invited Talk: Population Sizing for Genetic Programming Based Upon Decision Making
K. Sastry, U.-M. O'Reilly, and D. E. Goldberg

9:30 -- 9:55
Parameter Sweeps For Exploring GP Parameters
M. E. Samples, J. M. Daida, M. Byom, and M. Pizzimenti

9:55 -- 10:20
Genetic Programming: Parametric Analysis of Structure Altering Mutation Techniques
A. Piszcz and T. Soule

10:20 -- 10:40
Coffee Break

10:40 -- 11:05
Investigations in Meta-GAs: Panaceas or Pipe Dreams?
J. Clune, S. Goings, B. Punch, and E. Goodman

11:05 -- 11:30
A Review of Adaptive Population Sizing Schemes in Genetic Algorithms
F. G. Lobo and C. F. Lima

11:30 -- 11:55
Invited Talk: Online Population Size Adjusting Using Noise and Substructural Measurements
T.-L. Yu, K. Sastry, and D. E. Goldberg

11:55 -- 12:30
Panel Discussion


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   Workshop Chairs
Fernando Lobo and Claudio Lima
Departamento de Engenharia Electrónica e Informática
Universidade do Algarve
Campus de Gambelas, 8000 Faro
Portugal
Phone: +351-289-800900
Fax: +351-289-819403
E-mail:



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   Program Committee

Jonatan Gómez, National University of Colombia, Colombia
Shouichi Matsui, Central Research Institute of Electric Power Industry, Japan
Zbigniew Michalewicz, University of North Carolina, USA
Gabriela Ochoa, Simon Bolivar University, Venezuela
Martin Pelikan, University of Missouri, USA
Robert E. Smith, University of the West of England, UK
Eduardo Spinosa, Federal University of Paraná, Brazil

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   Talk Abstracts

Population Sizing for Genetic Programming Based Upon Decision Making
K. Sastry, U.-M. O'Reilly, and D. E. Goldberg

We develop a facetwise population-sizing relationship for genetic programming (GP). Following the population-sizing derivation for genetic algorithms in Goldberg, Deb, and Clark (1992), we consider building-block-wise decision making as a key facet. The analysis yields a GP-unique relationship because it has to account for bloat and for the fact that GP solutions often use subsolutions multiple times. The population-sizing relationship depends upon tree size, solution complexity, problem difficulty and building block expression probability. The relationship is used to analyze and empirically investigate population sizing for three model GP problems named ORDER, ON-OFF and LOUD. These problems exhibit bloat to differing extents and differ in whether their solutions require the use of a building block multiple times.

Parameter Sweeps For Exploring GP Parameters
M. E. Samples, J. M. Daida, M. Byom, and M. Pizzimenti

This paper describes our procedure and a software application for conducting large parameter sweep experiments in genetic and evolutionary computation research. Both procedure and software allows a researcher to examine multivariate nonlinearities that are common in genetic and evolutionary computation. Experiments of this nature are well suited to distributed computing environments (such as Grids and clusters) and we present an automated system for conducting parameter sweep experiments on heterogeneous networks. Emphasis is placed on experimental sampling, distributed robustness, and data analysis. The parameter sweep experimental procedure is easily applicable to any experiment involving computer simulations but is particularly well suited for evolutionary computation experiments.

Genetic Programming: Parametric Analysis of Structure Altering Mutation Techniques
A. Piszcz and T. Soule

We hypothesize that the relationship between parameter settings, specifically parameters controlling mutation, and performance is non-linear in genetic programs. Genetic programming environments have few means for a priori determination of appropriate parameters values. The hypothesized nonlinear behavior of genetic programming creates difficulty in selecting parameter values for many problems. In this paper we study three structure altering mutation techniques using parametric analysis on a problem with scalable complexity. We find through parameter analysis that two of the three mutation types tested exhibit nonlinear behavior. Higher mutation rates cause a larger degree of nonlinear behavior as measured by fitness and computational effort. Characterization of the mutation techniques using parametric analysis confirms the nonlinear behavior. In addition, we propose an extension to the existing parameter setting taxonomy to include commonly used structure altering mutation attributes. Finally we show that the proportion of mutations applied to internal nodes, instead of leaf nodes, has a significant effect on performance.

Investigations in Meta-GAs: Panaceas or Pipe Dreams?
J. Clune, S. Goings, B. Punch, and E. Goodman

A meta-GA (GA within a GA) is used to investigate evolving the parameter settings of genetic operators for genetic and evolutionary algorithms (GEA) in the hope of creating a self-adaptive GEA. We report three findings. First, the meta-GA can adapt its genetic operators to different problems and thereby perform well on average across diverse problems. Second, the meta-GA can change its parameters during the course of a run - seemingly a good idea - but this behavior may actually decrease performance. Finally, the genetic operator configurations the meta-GA evolves are far from optimal. We conclude that, while meta-GAs show promise for automating some parameter configurations, they are not likely to replace manually configured genetic and evolutionary algorithms without innovative alteration.

A Review of Adaptive Population Sizing Schemes in Genetic Algorithms
F. G. Lobo and C. F. Lima

This paper reviews the topic of population sizing in genetic algorithms. It starts by revisiting theoretical models which rely on a facetwise decomposition of genetic algorithms, and then moves on to various self-adjusting population sizing schemes that have been proposed in the literature. The paper ends with recommendations for those who design and compare adaptive population sizing schemes for genetic algorithms.

Online Population Size Adjusting Using Noise and Substructural Measurements
T.-L. Yu, K. Sastry, and D. E. Goldberg

This paper proposes an online population size adjustment scheme for genetic algorithms. It utilizes linkage-model-building techniques to calculate the parameters used in facetwise population-sizing models. The methodology is demonstrated using the dependency structure matrix genetic algorithm on a set of boundedly-difficult problems. Empirical results indicate that the proposed method is both efficient and robust. If the initial population size is too large, the proposed method automatically decreases the population size, and thereby yields significant savings in the number of function evaluations required to obtain high-quality solutions; if the initial population size is too small, the proposed scheme increases the population size on-the-fly and thereby avoiding premature convergence.

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