2020

Heure:	10:30 - 11:30
Lieu:	Salle B107, bâtiment B, Université de Villetaneuse
Résumé:	Multi-period Hub Location Problem with Serial Demands: A Case Study of Humanitarian Aids Distribution in Lebanon
Description:	Shahin Gelareh We address the problem of humanitarian aids distribution across refugee camps in war-ridden areas from a network design perspective. We show that the problem can be modeled as a variant of multi-period hub location problem with a particular demand pattern resulted by the user's behavior. The problem has been motivated by a case study of Lebanese experience in Syrian war refugee accommodation. We elaborate on the complexity and real-life constraints and, propose a compact formulation of a mathematical model of the problem. We then show that modeling the problem using a Benders paradigm drives O(n^3) variables of the original compact model unnecessary in addition to the constraints that are being projected out in a typical Benders decomposition. Additionally, we identify several classes of valid inequalities together with efficient separation procedures leading to a cut-and-Benders approach. Our extensive computational experiments on the case study with real data as well as randomly generated instances proves the performance of proposed solution methods.

Heure:	10:30 - 11:30
Lieu:	Salle B107, bâtiment B, Université de Villetaneuse
Résumé:	Méthodes primal-dual avec la programmation linéaire des configurations
Description:	Nguyen Kim Thang Primal-duale est une méthode élégante et puissante en optimisation et en algorithmique. La méthode consiste à établir de manière interactive des solutions primals et duales, puis un algorithme, ainsi que son analyse, sont guidés naturellement par l'interaction primal-duale. Dans cet exposé, je vais présenter les approches primal-dual comme techniques unifiées afin d'étudier et de développer les algorithmes les domaines de la théorie des jeux algorithmiques et de l'algorithmique en ligne.