1. Department of Computer Science, Columbia University Mudd Building, 500 W 120th St, New York, NY 10027, USA
2. GEODE, Université Paris 8, Campus Condorcet, Bâtiment Nord, 14, cours des Humanités, 93322 Aubervilliers, France
3. Polytech Annecy-Chambery, Université de Savoie, 5 chemin de Bellevue, 74940 Annecy, France