We present a branch-and-price-and-cut algorithm for solving large-scale instances of the multicommodity capacitated fixed-charge network design problem. We assume good feasible solutions are already known and we focus on an efficient algorithm for proving the optimality of the solutions. The restricted master problem solved at each column generation iteration is obtained directly from the compact arcbased model by considering only a subset of the commodity flow variables. The pricing subproblem corresponds to a Lagrangian relaxation of the flow conservation and capacity constraints, leaving in the Lagrangian subproblem only the strong inequalities. The column generation procedure is completed by a cut generation step based on strong inequalities. The resulting column-and-row generation procedure is embedded within an enumerative scheme. Computational experiments on a large set of randomly generated instances are presented and analyzed.
Cet article a pour but de présenter les résultats d’une recherche portant sur la socialisation professionnelle d’enseignant·e·s formé·e·s à l’étranger s’intégrant dans les écoles montréalaises. Une série d’entretiens collectifs a été proposée à certain·e·s d’entre elles·eux et à des pairs mentors afin de co-analyser des évènements concrets ayant marqué leur intégration et de débattre de leurs significations. Les résultats mettent en lumière deux dimensions majeures de leur socialisation : le rapport aux élèves et la régulation des conduites dans les classes, et la participation à la communauté de pairs et la définition de la compétence professionnelle.
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