Four-state domestic occupancy model

This is an implementation of the model described in the paper "Four-state domestic building occupancy model for energy demand simulations" by Eoghan McKenna, Michal Krawczynski, and Murray Thomson available here http://dx.doi.org/10.1016/j.enbuild.2015.03.013. The latest version of the model can be found here https://dspace.lboro.ac.uk/2134/15726. The four states of occupancy are described in terms of a "combined state" variable consisting of a first binary variable describing the occupancy state (1 = “at home”, 0 = “not at home”) and a second binary variable describing the activity state (1 = “active”, 0 = “not active”). This model is an extension of the two-state Domestic Active Occupancy Model by Ian Richardson and Murray Thomson (available at https://dspace.lboro.ac.uk/2134/3112).