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Position-Independent Street Searching

  • Christoph A. Bröcker
  • Alejandro López-Ortiz
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 1663)

Abstract

A polygon P is a street if there exist points (u,v) on the boundary such that P is weakly visible from any path from u to v. Optimal strategies have been found for on-line searching of streets provided that the starting position of the robot is s = u and the target is located at t = v. Thus a hiding target could foil the strategy of the robot by choosing its position t in such a manner as not to realize a street. In this paper we introduce a strategy with a constant competitive ratio to search a street polygon for a target located at an arbitrary point t on the boundary, starting at any other arbitrary point s on the boundary. We also provide lower bounds for this problem. This makes streets only the second non-trivial class of polygons (after stars) known to admit a constant-competitive-ratio strategy in the general position case.

Keywords

Competitive Ratio Simple Polygon Polygonal Chain Reflex Vertex Visibility Polygon 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag Berlin Heidelberg 1999

Authors and Affiliations

  • Christoph A. Bröcker
    • 1
  • Alejandro López-Ortiz
    • 2
  1. 1.Institut für InformatikUniversität FreiburgFreiburg
  2. 2.Faculty of Computer ScienceUniversity of New BrunswickFredericton, New BrunswickCanada

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