Title: Geometric Approximation Using Coresets: Old & New Results Speaker: Pankaj K. Agarwal Duke University Date: Friday, Dec 14, 2007 Time 11:00-12:00PM Venue: Room 3464, HKUST Abstract: The paradigm of coresets has recently emerged as a powerful tool for developing fast approximation algorithms for geometric optimization problems. For a given tolerance, the technique computes a ``core'' subset of the input points that approximates an underlying measure of the whole set. It is shown that for a wide range of interesting measures, the size of the coreset depends upon the approximation error but is independent of the size of the input set, and the coreset can be computed efficiently. Some of the problems that have benefited from this approach including, shape fitting, clustering, maintaining the extent of moving points, maintaining geometric summaries of data streams, and collision-free shortest paths. This talks gives an overview of known results and discusses some of the open problems.