McGill University - School of Computer Science

Computational Geometry Seminar

Everybody is welcome.

DATE: Friday, October 31st, 1997
TIME: 14h00 - 15h00 <-- Note new time !!!
PLACE: McConnell 320
TITLE: "On the Visibility Graph of Convex Translates"
SPEAKER: Prof. David Rappaport, School of Computer Science, Queen's University.

Let S denote a set of non-intersecting translates of the same closed compact convex object. We say that two objects a and b from the set S see each other if there exists a straight line segment l with one point in a and one point in b such that l does not intersect the interior of any other object in S. We call such a line segment a line of sight. The visibility graph of S, denoted by Vis(S), associates a vertex to each object of S, and an edge between two vertices if the associated objects see each other. We show that Vis(S) always contains a Hamiltonian path, for translates of a convex object. We also show that this path can be found with an efficient algorithm without having to explicitly determine Vis(S). Furthermore, we show that every other edge in the Hamiltonian path can be used to obtain a maximal matching that is realized by a set of non intersecting lines of sight.
This information is available at http://cgm.cs.mcgill.ca/~therese/seminar.
Direct questions, comments, additions to and removals from the mailing list, and suggestions for speakers to Therese Biedl at therese@cgm.cs.mcgill.ca.