Affiliation: | (1) Technological Institute Room 1744, Northwestern University, 60201 Evanston, IL, USA;(2) IRISA, Lab. associé au CNRS, Université de Rennes, F-35031 Rennes Cedex, France;(3) Dept. Mathematics and Statistics, Purdue University, 47907 Lafayette, IN, USA;(4) Department of Mathematics, University of California, 92093 San Diego La Jolla, CA, USA |