Nonlinear Dynamics, Psychology, and Life Sciences, Vol. 14, Iss. 2, April, 2010, pp. 145-149
@2010 Society for Chaos Theory in Psychology & Life Sciences


The Sheperd Equation and Chaos Identification

Robert A. M. Gregson, Australian National University

Abstract: An equation created by Sheperd (1982) to model stability in exploited fish populations has been found to have a wider application, and it exhibits complicated internal dynamics, including phases of strict periodicity and of chaos. It may be potentially applicable to other psychophysiological contexts. The problems of determining goodness-of fit, and the comparative performance of alternative models including the Shephed model, are briefly addressed.

Keywords: Sheperd model, dynamics, chaos, response function, Bayes, Lyapunov