Stable determination outside a cloaking region of two time-dependent   coefficients in an hyperbolic equation from Dirichlet to Neumann map
  In this paper, we treat the inverse problem of determining two time-dependent coefficients appearing in a dissipative wave equation, from measured Neumann boundary observations. We establish in dimension $n\geq 2$, stability estimates with respect to the Dirichlet-to-Neumann map of these coefficients provided that are known outside a cloaking regions. Moreover, we prove that it can be stably recovered in larger subsets of the domain by enlarging the set of data 
Mourad Bellassoued and Ibtissem Ben Aicha
math.AP