A Note on Edge Guards in Art Galleries
  We examine the Art Gallery Problem with Edge Guards. We present a heuristic algorithm to arrange edge guards to guard only the inward side of the walls of any N-vertex simple polygonal gallery using at most roof (N/4) edge guards - a weakened version of Toussaint's conjecture on the number of edge guards that can guard an entire simple polygon. Our study indicates that solving this weaker problem could give a handle on the full problem. 
R. Nandakumar
math.MG math.CO