Electronic Journal of Differential Equations,
Vol. 2001(2001), No. 50, pp. 1-19.

Title: An abstract approximate controllability result and applications to 
       elliptic and parabolic systems with dynamic boundary conditions
        
Authors: Ioan Bejenaru (Northwestern Univ., Evanston, IL, USA)
         Jesus Ildefonso Diaz (Univ. Complutense, Madrid, Spain)
         Ioan I. Vrabie (Al. I. Cuza  Univ., Iasi, Romania)

Abstract:  
  In this paper we prove an approximate controllability result for
  an abstract semilinear evolution equation in a Hilbert space and we obtain
  as consequences the approximate controllability for some classes of elliptic
  and parabolic problems subjected to nonlinear, possible non monotone, dynamic
  boundary conditions.
  
Submitted April 23, 2001. Published July 11, 2001.
Math Subject Classifications: 93B05, 93C20, 93325, 35B37
Key Words: approximate controllability; evolution equation; parabolic problem; 
           elliptic problem; dynamic boundary conditions.