From Local to Global Optimization W. Vogel & M. Büttner GmbH Es sind auch die Griinde MEng. F. Lucka Es sind auch die Griinde A cursory review of their contents shows such a diversity of topics and approaches that one might well infer that there are no genuine criteria for classifying a paper or a lecture as a contribution to Cognitive Science and Peter Varbrand November 1998 xv Hoang Tuy: An Appreciation Its a pleasure for me as colleague and friend to take this opportunity to celebrate Hoang 'I\lY'S numerous contributions to the field of mathemat­ ical programming The conference gave us the opportunity to cel­ ebrate Hoang Thy's achievements in Optimization during his 70 years of life