Exact Bounded Boundary Controllability to Rest for the Two-Dimensional   Wave Equation
  The problem of the exact bounded control of oscillations of the two-dimensional wave equation is considered. Control force is applied to the boundary of the membrane, which is located in a domain on a plane. The goal of the control is to drive the system to rest in a finite time. 
Igor Romanov and Alexey Shamaev
math.AP