2025

Heure:	10:30 - 11:30
Lieu:	Salle G201
Résumé:	Quantum algorithms for optimization
Description:	Camille Grange Quantum computation is a new paradigm that is increasingly being exploited today for designing methods to solve optimization problems. Although its application to numerical instances is limited, among other reasons due to the lack of quantum RAM, theoretical advantages are emerging compared to classical approaches for several classes of problems. In this talk, we provide insights into what makes quantum algorithms powerful for optimization and illustrate it with a new bounded-error quantum-classical algorithm. Specifically, this algorithm combines the generalization of Grover Search with dynamic programming to polynomially reduce the worst-case time complexity of NP-hard minimization problems satisfying certain properties. We exemplify it on several scheduling problems.

Heure:	10:30 - 11:30
Lieu:	Salle A303
Résumé:	A double ALNS metaheuristic for the multi-commodity location-network design problem with selection of heterogeneous vehicles
Description:	Francesco Contu This work investigates a decision support system for planning a consolidation-based distribution system in a city where inbound freight arrives in containers at an intermodal terminal. Since this facility lacks storage and transdock capabilities, containers must be transferred to satellite facilities to be unpacked and reloaded onto smaller vehicles. The problem is approached from the perspective of an urban mobility manager, who must select the satellite facilities and vehicles, define their routes, and determine the commodity flows to final destinations, while optimizing transportation resources. The problem is formulated as a Mixed-Integer Linear Programming model. To address realistically sized instances, a metaheuristic based on two Adaptive Large Neighborhood Searches (ALNSs) is proposed: the outer ALNS selects satellites and vehicles, and assigns containers to satellites; the inner ALNS handles routing and allocation decisions on the second echelon. These procedures are run iteratively. The metaheuristic is used to conduct an extensive experimental campaign using data from the city of Cagliari (Italy) to evaluate the distribution system.