Good luck with your project. Unfortunately, there have been a number of academic studies on pilot fatigue, and other related topics, but the regulatory bodies have simply ignored them. At the end of the day the big bucks, and influence, of the bigger companies seems to hold sway.
It is a very important issue, and I do hope that you not only get a lot of input to complete your study, but that someone in one of the towers of officialdom wakes up long enough to read it, and take it seriously.
Good luck.