Position-Independent Near Optimal Searching and On-line Recognition in Star Polygons

. We study the problem of on-line searching for a target inside a polygon. In particular we propose a strategy for finding a target of unknown location in a star polygon with a competitive ratio of 14.5, and we further refine it to 12.72. This makes star polygons the first non-trivial class of polygons known to admit constant competitive searches independent of the position of the target. We also provide a lower bound of 9 for the competitive ratio of searching in a star polygon---which is close to the upper bound. A similar task consists of the problem of on-line recognition of star polygons for which we also present a strategy with a constant competitive ratio including negative instances. 1 Introduction In the past years on-line searching has been an active area of research in Computer Science (e.g. [1, 2, 4, 7, 8, 11]). In its full generality, an on-line search problem consists of an agent or robot searching for a target on an unknown terrain. In the worst case a search by a robot..