Regrettably I haven't looked at any of my thesis stuff for over three years now. I actually had a look for the definitions a couple of weeks back for a few others who were after them. I know they are hiding on some of my old harddrives somewhere.
I will have another look but without access to GH at the moment it is hard to check what is what.
From memory I used the plugin Spiderweb to establish programatic relationships. I then used these as the spring lengths in the Kangaroo simulation.