N. Vlassis-received-the and M. Sc, degree in electrical and computer engineering (1993) and the Ph.D. degree in artificial intelligence (1998) from the National Technical University of Athens, Greece In 1998 he joined the Intelligent Autonomous Systems Group at the University of Amsterdam , The Netherlands, where he is now holding an assistant professor position, he was a visiting researcher at the Electrotechnical Laboratory (currently AIST), Japan, with a scholarship from the Japan Industrial Technology Association MITI. He holds the Dimitris N. Chorafas Foundation prize) for young researchers in Engineering and Technology. His research focusses on probabilistic and statistical learning methods for intelligent systems, 1999.

J. J. Verbeek, received in 1998 a cum laude Masters degree in Artificial Intelligence and a cum laude Master of Logic degree in 2000, both at the University of Amsterdam, the Netherlands he is a PhD student in the Advanced School for Computing and Imaging, working in the Intelligent Autonomous Systems group at the University of Amsterdam. Current research activities take place in a project on nonlinear feature extraction. Research interests include principal curves and surfaces, non parametric density estimation and machine learning in general, 1975.