En hommage à Joseph-Louis Lagrange et à Pierre Huard

Abstract

The contributions to science of Joseph-Louis Lagrange (or Giuseppe Luigi Lagrangia, since after all, even though of French descent, he was born in Torino!) are too many for me to list and even more, to comprehend. Like a number of other intellectual giants of the 18th and 19th century, he was familiar with most branches of science, and few people today can boast such breadth and depth of knowledge. His influence on many branches of mathematics is still profound. And yet, if it had not been for his father's unhealthy financial situation, he might have chosen to spend his time differently; he is quoted as saying "If I had been rich, I probably would not have devoted myself to mathematics." After mentally thanking his father for his unsuccessful speculations, I will limit my homage to his study of "extrema liés", i.e., extrema of functions of several variables subject to equality constraints, and by extension to inequality constraints, and of so-called Lagrangean multipliers, as they relate to my own research.How did I get to hear of his work? I had always liked mathematics, and at the University of Lille, in northern France, some 30 km from the town where my parents lived, I had initially studied exclusively pure mathematics, obtaining a "licence", then a DES (Diplôme d'Etudes Supérieures). This being in France, we studied abstract algebra and so-called (at least then) modern mathematics. Bourbaki and Cauchy were household names. One of the DES topics of study was category theory. I could not really visualize myself doing research M. Guignard ( )

Implementation of a Mathematical Model to Improve Sustainability in the Handling of Transport Costs in a Distribution Network

“…In the work developed by the authors of reference [12] for the case of large problems where computing time is of the essence when obtaining a solution, the use of Lagrangian relaxation is proposed to generate lower bounds [17], which necessitates adding a penalty term to the objective function to avoid violating relaxed restrictions. When resolving the Lagrangian problem, a lower bound is returned for original optimal objective value minimization problems.…”