Identifying a space dependent coefficient in a reaction-diffusion equation

We consider a reaction-diffusion equation for the front motion [u] in which the reaction term is given by [c(x)g(u)]. We formulate a suitable inverse problem for the unknowns [u] and [c], where [u] satisfies homogeneous Neumann boundary conditions and the additional condition is of integral type on the time interval [[0,T]]. Uniqueness of the solution is proved in the case of a linear [g]. Assuming [g] non linear, we show uniqueness for large [T].