Affiliation: | aÉcole Polytechnique de Montréal, Département de Mathématique et de génie industriel, C.P. 6079, Succ. Centre-Ville, Montréal, Quebec, Canada H3C 3A7;bCIRANO (Center for Interuniversity Research and Analysis on Organization), 2020, University, Montréal, Quebec, Canada H3A 2A5 |