This is a synopsis of an academic paper from more than a decade ago. I didn't see the full paper online, but it would be easy enough to get from a library that can get stuff from universities.
It doesn't sound very sharp, but it is all about modeling and I thought it might be of interest to some.
http://www.questia.com/googleScholar.qst;jsessionid=LhKBJnLJkXQ 4KnphHcmkhtMMG4h0hnh0SNLjF4Q8JzMw6b7hDpk 1!-650820450!1517079229?docId=5001659925