This just a numerical simulation on two (simple) models of the human sleep cycle system that tries to find a more efficient way of shifting the cycle of those methods.

I've only spend 40 minutes reading the paper so far and only have a superficial understanding of it, but to me it looks like they are using a somewhat oscillator like model and looking to introduce a phase shift in the response by driving it with different input functions.

There is no experimental verification whatsoever. This is why this was in the computational biology section of plosone.