Online Exploration of Polygons with Holes
  We study online strategies for autonomous mobile robots with vision to explore unknown polygons with at most h holes. Our main contribution is an (h+c_0)!-competitive strategy for such polygons under the assumption that each hole is marked with a special color, where c_0 is a universal constant. The strategy is based on a new hybrid approach. Furthermore, we give a new lower bound construction for small h. 
Robert Georges, Frank Hoffmann, Klaus Kriegel (Freie Universit\"at   Berlin, Germany)
cs.CG cs.DS cs.RO