McKean

McKean suggested two models, both with $F(v,w) = f(v) - w$ and $G(v,w) = \epsilon(v-\gamma w)$. For the first,

$$f(v) = \left\{\begin{array}{cc}-v &v<{\alpha\over 2}\\ v-\a... ...1+\alpha\over 2}\\ 1-v&v >{1+\alpha\over 2} \end{array}\right.$$ (5)

where $0 < \alpha < {1\over 2}$.

The second model suggested by McKean had

$$f(v) = \left\{\begin{array}{cc}-v &v<\alpha\\ 1-v&v >\alpha \end{array}\right.$$ (6)

and $\gamma = 0$. This is an extremely popular model with hundreds of related papers.