Complex Systems

Two-Step Markov Update Algorithm for Accuracy-Based Learning Classifier Systems Download PDF

Mohammad Razeghi-Jahromi
Shabnam Nazmi
Abdollah Homaifar

Department of Electrical and Computer Engineering
North Carolina A&T State University
Autonomous Control and Information Technology (ACIT) Institute
1601 East Market Street
Fort IRC Building
Greensboro, NC 27411, USA
mohammad.razeghi-jahromi@us.abb.com
snazmi@aggies.ncat.edu
homaifar@ncat.edu

Abstract

In this paper, we investigate the impact of a two-step Markov update scheme for the reinforcement component of XCS, a family of accuracy-based learning classifier systems. We use a mathematical framework using discrete-time dynamical system theory to analyze the stability and convergence of the proposed method. We provide frequency domain analysis for classifier parameters to investigate the achieved improvement of the XCS algorithm, employing a two-step update rule in the transient and steady-state stages of learning. An experimental analysis is performed to learn to solve a multiplexer benchmark problem to compare the results of the proposed update rules with the original XCS. The results show faster convergence, better steady-state training accuracy and less sensitivity to variations in learning rates.

Keywords: two-step Markov update rule; accuracy-based classifier system; stability and convergence analysis; linear discrete-time dynamical system