1. Istituto Dalle Molle di studi sull’Intelligenza Artificiale (IDSIA), Manno, Switzerland;
2. UQOD, Idiap Research Institute Centre du Parc, Martigny, Switzerland;
3. IMSV, Department of Mathematics and Statistics, University of Bern, Bern, Switzerland;
4. BRGM, Orléans Cedex, France