Stephen Dignum
University of Essex
15 Papers
149 Citations
Stephen Dignum is an academic researcher from University of Essex. The author has contributed to research in topics: Crossover & Genetic programming. The author has an hindex of 9, co-authored 15 publications.
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Papers
Operator equalisation for bloat free genetic programming and a survey of bloat control methods
TL;DR: This paper presents a comprehensive survey and taxonomy of many of the bloat control methods published in the literature through the years, and examines the evolutionary dynamics of OpEq and its potential to be extended and integrated into different elements of the evolutionary process.
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On the limiting distribution of program sizes in tree-based genetic programming
Riccardo Poli,William B. Langdon,Stephen Dignum +2 more
- 11 Apr 2007
TL;DR: There is strong theoretical and experimental evidence that standard sub-tree crossover with uniform selection of crossover points pushes a population of a-ary GP trees towards a distribution of tree sizes of the form of Pr{n} = (1 - apa) (an+1 n) (1-pa)(a-1)n+1 pan where n is the number of internal nodes in a tree and pa is a constant.
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Automatically structuring domain knowledge from text: An overview of current research
Malcolm Clark,Yunhyong Kim,Udo Kruschwitz,Dawei Song,Dyaa Albakour,Stephen Dignum,Ulises Cerviño Beresi,Maria Fasli,Anne De Roeck +8 more
TL;DR: An overview of automatic methods for building domain knowledge structures (domain models) from text collections inspired by the ubiquitous propagation of domain model structures that are emerging in several research disciplines is given.
Extending Operator Equalisation: Fitness Based Self Adaptive Length Distribution for Bloat Free GP
Sara Silva,Stephen Dignum +1 more
- 10 Apr 2009
TL;DR: This work improves operator equalisation by giving it the ability to automatically determine and follow the ideal length distribution for each stage of the run, unconstrained by a fixed maximum limit.
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Crossover, sampling, bloat and the harmful effects of size limits
Stephen Dignum,Riccardo Poli +1 more
- 26 Mar 2008
TL;DR: It is predicted that, in the presence of fitness, size limits may initially speed up bloat, almost completely defeating their original purpose (combating bloat), which leads us to suggest a better way of using size limits.
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