This thesis aims to present families of fully and partially discretised formulations for vehicle routing problems with delivery decisions. These formulations bridge an existing gap in the literature for the targeted problems, namely SDVRP variants, with or without time windows, and the IRP. Existing BCP implementations in the literature for these problems rely on a concept that may require several rounds of column generation. This detrimental effect is not present in our proposed formulations. In addition, we adapt existing and novel families of non-robust inequalities for these problems by employing the limited-memory technique. Several cut separation procedures are implemented to separate robust and non-robust inequalities. Especially for SDVRP variants, we highlight that our separation algorithms are generic and capable of finding valid cuts violated for both CVRP and SDVRP variants.
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Authors: Fulin Yan, François Clautiaux, Aurélien Froger, Boris Albar
Abstract: In this work, we propose a generic heuristic for the resource-constrained shortest path problem derived from dynamic programming reformulations of hard combinatorial optimization problems. The approach is a machine-learning (ML)-augmented beam search [Read more]
Authors: Ayse N. Arslan, Michael Poss
Abstract: Uncertainty reduction has recently been introduced in the robust optimization literature as a relevant special case of decision-dependent uncertainty. Herein, we identify two relevant situations in which the problem is polynomially solvable. We provi [Read more]
Authors: Boris Detienne, Henri Lefebvre, Enrico Malaguti, Michele Monaci
Abstract: In this work, we study optimization problems where some cost parameters are not known at decision time and the decision flow is modeled as a two-stage process within a robust optimization setting. We address general problems in which all constraints [Read more]
This thesis focuses on algorithmic design for three combinatorial optimization problems related to transportation, logistics and production research with specific types of indus- trial constraints. First, we consider the Precedence Constrained Generalized Traveling Salesman Problem (PCGTSP). This problem is an extension of two well-known combinatorial optimization problems — the Generalized Traveling Salesman Problem (GTSP) and the Precedence Constrained Asymmetric Traveling Salesman Problem (PCATSP), whose path version is known as the Sequential Ordering Problem (SOP).
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Authors: Xavier Blanchot, François Clautiaux, Aurélien Froger, Manuel Ruiz
Abstract: In this paper, we study how a regulatory constraint limiting a measure of unserved demand, called Loss Of Load Expectation (LOLE), can be incorporated into a strategic version of a stochastic generation and transmission expansion planning problem. Th [Read more]