Froger

A three-year PhD position at EDF with the Inria center of the University of Bordeaux (EDGE team) is open.
[Read more]

CATIE (Centre Aquitain des Technologies de l’Information et Électroniques) is a non-profit organization created in 2014 based in the Région Nouvelle-Aquitaine. As a technology resources center specialized in digital technology, its main mission is to support SMEs and intermediate size companies in their digital transformation and to help them embracing and integrating related technologies.

Our collaboration with CATIE is about machine learning and optimization. We focus on problems related to shortest path problem with side constraints.

[Read more]

EDF is the major French multinational electric utility company owned by the French state. Our collaboration is part of the EDF-Inria Challenge, and specifically a project titled “Decomposition algorithms for solving generation expansion planning problems”.
[Read more]

A two-year postdoctoral position is open at the Inria center of the University of Bordeaux (EDGE team) with a collaboration with EDF.
[Read more]

Description

Repository containing a C++ implementation of the Benders by batch algorithm described in the article:

Xavier Blanchot, François Clautiaux, Boris Detienne, Aurélien Froger, Manuel Ruiz. (2023). The Benders by batch algorithm: design and stabilization of an enhanced algorithm to solve multicut Benders reformulation of two-stage stochastic programs. European Journal of Operational Research. DOI: 10.1016/j.ejor.2023.01.004

[Read more]

Authors: Luis Marques, François Clautiaux, Aurélien Froger
Abstract: We study the problem of designing a cabinet made up of a set of shelves that contain compartments whose contents slide forward on opening. Considering a set of items candidate to be stored in the cabinet over a given time horizon, the problem is to d [Read more]

Authors: Xuan Ren, Aurélien Froger, Ola Jabali, Gongqian Liang
Abstract: We propose a heuristic algorithm capable of handling multiple variants of the vehicle routing problem with drones (VRPD). Assuming that the drone may be launched from a node and recovered at another, these variants are characterized by three axes, (1 [Read more]

Authors: Brais González-Rodrı́guez, Aurélien Froger, Ola Jabali, Joe Naoum-Sawaya
Abstract: Establishing the size of an EV fleet is a vital decision for logistics operators. In urban settings, this issue is often dealt with by partitioning the geographical area around a depot into service zones, each served by a single vehicle. Such zones u [Read more]

In this internal workshop, we review the recent literature on Lagrangian variable fixing techniques.

The presentation is about the following submitted paper:

Xavier Blanchot, François Clautiaux, Aurélien Froger, Manuel Ruiz. (2023). Modeling and solving a stochastic generation and transmission expansion planning problem with a “Loss Of Load Expectation” reliability criterion. (hal-03957750v2)

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]

We consider general aggregation/disaggregation techniques to address optimization problems that are expressed with the help of sequential decision processes. Our main goals are threefold: a generic formalism that encompasses the aforementioned techniques ; more efficient algorithms to control the aggregation procedures ; open-source codes that leverage and integrate these algorithms to efficiently solve hard combinatorial problems in different application fields.
[Read more]

Supervisors

• François Clautiaux (Edge)
• Aurélien Froger (Edge)

PhD title: Solving combinatorial optimization problems using hybrid methods that combine machine learning techniques with existing optimization techniques

Objective of the thesis

We wish to develop heuristic approaches based on hybrid methods to solve problems formulated using Sequential decision processes (SDP). One difficulty is that these approaches only have implicit knowledge of the problem to be solved (via oracles for example). When the problem is very large, it is not possible to generate all of the possible states, and the proposed methods must use exploration phases.

Another objective of the thesis is to provide efficient procedures for the techniques which are used in the resolution of SDP based on successive relaxations of the state space: in particular the oracle which allows to choose the states to be aggregated or disaggregated.

---

Publications

Journal articles 24

Preprints (24)

HDR (24)

Thesis (24)

Conferences and workshops (24)

Book chapters (24)

Reports (24)

---

Ph.D title: Aggregation-disaggregation techniques for solving large network-flow models

Supervisors: François Clautiaux (Edge) and Aurélien Froger (Edge)

Objective of the thesis

We consider general aggregation/disaggregation techniques to address optimization problems that are expressed with the help of sequential decision processes. Our main goals are threefold: a generic formalism that encompasses the aforementioned techniques ; more efficient algorithms to control the aggregation procedures ; open-source codes that leverage and integrate these algorithms to efficiently solve hard combinatorial prcodeoblems in different application fields.

We will jointly study two types of approaches, MIP and SAT, to reach our goals. MIP-based methods are useful to obtain proven optimal solutions, and to produce theoretical guarantees, whereas SAT solvers are strong to detect infeasible solutions and learn clauses to exclude these solutions. Their combination with CP through lazy clause generation is one of the best tools to solve highly combinatorial and non- linear problems. Aggregation/disaggregation techniques generally make use of many sub-routines, which allows an efficient hybridization of the different optimization paradigms. We also expect a deeper cross-fertilization between these different sets of techniques and the different communities.

---

Publications

Journal articles 24

Preprints (24)

HDR (24)

Thesis (24)

Conferences and workshops (24)

Book chapters (24)

Reports (24)

---

Supervisors

• Ayse Arslan (Edge)
• Boris Detienne (Edge)
• Aurélien Froger (Edge)

---

Publications

Journal articles 24

Preprints (24)

HDR (24)

Thesis (24)

Conferences and workshops (24)

Book chapters (24)

Reports (24)

---

RTE is France’s Transmission System Operator. It is in charge of the high and ultra-high voltage electricity transmission network in France and of the electricity exchanges with the neighbouring countries. Its main role is to guarantee in real time the balance between electricity production and consumption.

In 2019, a contract was signed with RTE for a PhD on algorithms to speedup Benders’ decomposition. The PhD student was Xavier Blanchot under the supervision of François Clautiaux and Aurélien Froger.

[Read more]