Affiliation: | a Département de Mathématiques, École Polytechnique Fédérale de Lausanne, CH-1015 Ecublens, Switzerland b GERAD and École Polytechnique de Montréal, 5255, Avenue Decelles, Montréal, Québec, Canada H3T 1V6 c Department of Electrical Engineering, Catholic University of Rio de Janeiro, Caixa Postal 38063, Rio de Janeiro 22452, Brazil |