IBM Watson Research Center, Yorktown Heights, NY, July 1999. Approximation algorithms for clustering problems. Invited plenary lecture. Distinguished Lecturer Series. University of Southern California Dept. of Computer Science, Los Angeles, CA, February 2000.
Approximation algorithms via linear programming.
UC Berkeley, Berkeley, CA, February 2000. . IBM Almaden Research Center, Almaden, CA, May 2000. Dagstuhl Workshop on randomization methods in combinatorial optimization, January 2000. . International Symposium on Mathematical Programming, Atlanta, GA, August 2000. Improved approximation algorithms for the k-level facility location problem.