The two-process model of Daan et. al (1984) was combined with a phase shifting and amplitude altering routine for better entrainment of the circadian processes by light. Genetic algorithms were used to find the appropriate model parameters for the natural distribution of different chronotypes (early birds, owls) that was published by Roenneberg (2007). As a breakthrough, the resulting distribution of one of the 8 free parameters - the circadian period - closely matched both distribution and average of the human circadian period published for experimantal data by Czeisler (1999).

These results were presented at the UKSim 2013 in Cambridge. A full description as publication and presentation are available here.

Chronotype Distribution

Distribution of Circadian Period