The École Polytechnique de Montréal is an engineering school/faculty affiliated with the Université de Montréal in Montreal, Quebec, Canada. It ranks first in Canada for the scope of its engineering research. It is occasionally referred to as Montreal Polytechnic, although in Quebec English its French name is more commonly used. The school offers graduate and postgraduate training, and is very active in research. Following tradition, new bachelors of engineering graduating from the École Polytechnique receive an Iron Ring, during the Canadian Ritual of the Calling of an Engineer ceremony. Wikipedia.
Mayer J.R.R.,Ecole Polytechnique de Montreal
CIRP Annals - Manufacturing Technology | Year: 2012
On-machine probing of a reconfigurable uncalibrated master balls artefact enriched with a ball bar artefact provides sufficient data to estimate all axis to axis location errors and some axis component errors of a five-axis machine tool. Numerical simulations supported by experimental trials are presented in the case of a five-axis horizontal machining centre using artefacts with up to 26 balls for estimation of ten location errors, including the spindle translational errors, and all three linear axes positioning linear error terms. Volumetric error prediction capability, the impact of data selection on parameter estimation and thermal effect tracking are addressed. © 2012 CIRP.
Desaulniers G.,Ecole Polytechnique de Montreal
Operations Research | Year: 2010
This paper addresses the split-delivery vehicle routing problem with time windows (SDVRPTW) that consists of determining least-cost vehicle routes to service a set of customer demands while respecting vehicle capacity and customer time windows. The demand of each customer can be fulfilled by several vehicles. For solving this problem, we propose a new exact branchand-price-and-cut method, where the column generation subproblem is a resource-constrained elementary shortest-path problem combined with the linear relaxation of a bounded knapsack problem. Each generated column is associated with a feasible route and a compatible delivery pattern. As opposed to existing branch-and-price methods for the SDVRPTW or its variant without time windows, integrality requirements in the integer master problem are not imposed on the variables generated dynamically, but rather on additional variables. An ad hoc label-setting algorithm is developed for solving the subproblem. Computational results show the effectiveness of the proposed method. © 2010 INFORMS.
Skorobogatiy M.,Ecole Polytechnique de Montreal
Optics Express | Year: 2014
I present several classes of analytical and semi-analytical solutions for the design of high-speed rotary optical delay lines that use a combination of stationary and rotating curvilinear reflectors. Detailed analysis of four distinct classes of optical delay lines is presented. Particularly, I consider delay lines based on a single rotating reflector, a single rotating reflector and a single stationary reflector, two rotating reflectors, and two rotating reflectors and a single stationary reflector. I demonstrate that in each of these cases it is possible to design an infinite variety of the optical delay lines featuring linear dependence of the optical delay on the rotation angle. This is achieved via shape optimization of the rotating and stationary reflector surfaces. Moreover, in the case of two rotating reflectors a convenient spatial separation of the incoming and outgoing beams is possible. For the sake of example, all the blades presented in this paper are chosen to fit into a circle of 10cm diameter and these delay lines feature in excess of 600ps of optical delay. Finally, two prototypes of rotary delay lines were fabricated using CNC machining, and their optical properties are characterized. © 2014 Optical Society of America.
Grmela M.,Ecole Polytechnique de Montreal
Entropy | Year: 2014
The time evolution during which macroscopic systems reach thermodynamic equilibrium states proceeds as a continuous sequence of contact structure preserving transformations maximizing the entropy. This viewpoint of mesoscopic thermodynamics and dynamics provides a unified setting for the classical equilibrium and nonequilibrium thermodynamics, kinetic theory, and statistical mechanics. One of the illustrations presented in the paper is a new version of extended nonequilibrium thermodynamics with fluxes as extra state variables.© 2014 by the authors.
Le Digabel S.,Ecole Polytechnique de Montreal
ACM Transactions on Mathematical Software | Year: 2011
NOMAD is software that implements the Mesh Adaptive Direct Search (MADS) algorithm for blackbox optimization under general nonlinear constraints. Blackbox optimization is about optimizing functions that are usually given as costly programs with no derivative information and no function values returned for a significant number of calls attempted. NOMAD is designed for such problems and aims for the best possible solution with a small number of evaluations. The objective of this article is to describe the underlying algorithm, the software's functionalities, and its implementation. © 2011 ACM.