Affiliation: | (1) CWI, P.O. Box 94079, 1090 GB Amsterdam, The Netherlands;(2) University of Amsterdam, Kruislaan 419, 1098 VA Amsterdam, The Netherlands;(3) Département d’Informatique, UQAM, C.P. 8888, Montreal, QC, Canada;(4) Ricoh Innovations, Inc., 2882 Sand Hill Road/115, Menlo Park, CA, USA |