Lea Ricard

Talks [6]

2024

Ricard L., Bierlaire M. The stochastic electric dial-a-ride problem with recourse September 03, 2024. International Conference on Operations Research 2024, , Munich, Germany.


@Misc{Ricard24_ORMunich,
  author = {L\'ea Ricard and Michel Bierlaire},
  title = {The stochastic electric dial-a-ride problem with recourse},
  howpublished = {\url{https://transp-or.epfl.ch/documents/talks/Ricard24_ORMunich.pdf}},
  year = {2024},
  note = {Presented at International Conference on Operations Research 2024, , Munich, Germany}}}

Ricard L., Desaulniers G., Lodi A., Rousseau L. Stochastic optimization of bus schedules July 21, 2024. International Symposium on Mathematical Programming, GERAD, Montreal, Canada.


@Misc{Ricard24_ISMP,
  author = {L\'ea Ricard and Guy Desaulniers and Andrea Lodi and Louis-Martin Rousseau},
  title = {Stochastic optimization of bus schedules},
  howpublished = {\url{https://transp-or.epfl.ch/documents/talks/Ricard24_ISMP.pdf}},
  year = {2024},
  note = {Presented at International Symposium on Mathematical Programming, GERAD, Montreal, Canada}}}

Ricard L., Desaulniers G., Lodi A., Rousseau L. Stochastic optimization of bus schedules June 30, 2024. European Conference on Operational Research, DTU, Copenhagen, Denmark.


@Misc{Ricard24_EURO,
  author = {L\'ea Ricard and Guy Desaulniers and Andrea Lodi and Louis-Martin Rousseau},
  title = {Stochastic optimization of bus schedules},
  howpublished = {\url{https://transp-or.epfl.ch/documents/talks/Ricard24_EURO.pdf}},
  year = {2024},
  note = {Presented at European Conference on Operational Research, DTU, Copenhagen, Denmark}}}

Ricard L., Desaulniers G., Lodi A., Rousseau L. Stochastic optimization of bus schedules June 27, 2024. Swiss OR days, HEG-Genève, Geneva, Switzerland.


@Misc{Ricard24_SwissOR,
  author = {L\'ea Ricard and Guy Desaulniers and Andrea Lodi and Louis-Martin Rousseau},
  title = {Stochastic optimization of bus schedules},
  howpublished = {\url{https://transp-or.epfl.ch/documents/talks/Ricard24_SwissOR.pdf}},
  year = {2024},
  note = {Presented at Swiss OR days, HEG-Gen\ève, Geneva, Switzerland}}}

2023

Ricard L., Desaulniers G., Lodi A., Rousseau L. Strategies for the electric bus scheduling problem with battery degradation: A stochastic perspective October 16, 2023. INFORMS 2023, Phoenix, Arizona, USA.


@Misc{Ricard23_INFORMS,
  author = {L\'ea Ricard and Guy Desaulniers and Andrea Lodi and Louis-Martin Rousseau},
  title = {Strategies for the electric bus scheduling problem with battery degradation: A stochastic perspective},
  howpublished = {\url{https://transp-or.epfl.ch/documents/talks/Ricard23_INFORMS.pdf}},
  year = {2023},
  note = {Presented at INFORMS 2023, Phoenix, Arizona, USA}}}

Ricard L., Desaulniers G., Lodi A., Rousseau L. The stochastic multi-depot electric vehicle scheduling problem with recourse September 07, 2023. 11th Symposium of the European Association for Research in Transportation, ETH Zurich, Zurich, Switzerland.


@Misc{Ricard23_HEART,
  author = {L\'ea Ricard and Guy Desaulniers and Andrea Lodi and Louis-Martin Rousseau},
  title = {The stochastic multi-depot electric vehicle scheduling problem with recourse},
  howpublished = {\url{https://transp-or.epfl.ch/documents/talks/Ricard23_HEART.pdf}},
  year = {2023},
  note = {Presented at 11th Symposium of the European Association for Research in Transportation, ETH Zurich, Zurich, Switzerland}}}

Research projects [1]

2024

Multi-objective disruption management for robust railway operations

In passenger railway services, a timetable defines the scheduled arrival and departure times of trains at designated stations. When a disruption occurs, the railway operator must establish a disposition timetable, a complex task due to the intricacies of rail operations and the interactions in the network. This research aims to develop a decision-support tool that optimizes disruption management using a multi-objective optimization approach. The tool will account for system constraints while minimizing passenger inconvenience, operational costs, and deviations from the original timetable. Designed with practitioners' needs in mind, it will be integrated into the industrial software Viriato, enabling the use of real production data for algorithm evaluation and refinement.
- Apr 01, 2024 - Oct 31, 2025
- Sponsor: Swiss Federal Railways (SBB)
- Principal investigator: Michel Bierlaire
- Project manager: Lea Ricard

EPFL courses [4]

Spring 2025

Optimization and Simulation.
- Level: PhD
- Section: Doctoral program in Civil and Environmental Engineering
- Lecturers: Michel Bierlaire, Cloe Cortes Balcells, Lea Ricard, Pavel Ilinov
- Webpage: http://transp-or.epfl.ch/courses/OptSim2025

Fall 2024

Introduction to optimization and operations research .
- Level: Bachelor
- Sections: Mechanical Engineering, Civil Engineering, Environmental Sciences and Engineering, Electrical and Electronics Engineering
- Lecturer: Michel Bierlaire
- Teaching assistants: Fabian Torres, Lea Ricard, Marija Kukic, Tom Haering, Negar Rezvany

Spring 2024

Optimization and Simulation.
- Level: PhD
- Section: Doctoral program in Civil and Environmental Engineering
- Lecturers: Michel Bierlaire, Cloe Cortes Balcells, Lea Ricard, Pavel Ilinov
- Webpage: http://transp-or.epfl.ch/courses/OptSim2024

Fall 2023

Introduction to optimization and operations research .
- Level: Bachelor
- Sections: Mechanical Engineering, Civil Engineering, Environmental Sciences and Engineering, Electrical and Electronics Engineering
- Lecturer: Michel Bierlaire
- Teaching assistants: Fabian Torres, Lea Ricard, Marija Kukic, Tom Haering, Negar Rezvany

MSc theses [2]

2024-2025

Integrating Advanced Discrete Choice Models into the Capacitated Facility Location Problem with Decentralized Priority Queues, Quoc Dang Tran (Mathematics)
- Supervision: Tom Haering, Lea Ricard
- External expert: Virginie Lurkin

2024

Stochastic on-demand electric vehicle routing and charge scheduling, Mohamed Essayouti (Mathematics)
- Supervision: Lea Ricard, Tom Haering, Michel Bierlaire
- External expert: Claudia Bongiovanni

Semester projects [2]

2024-2025

Optimization of railway maintenance planning, Younis Bouzar

Supervision: Lea Ricard, Marija Kukic, Michel Bierlaire
This project aims to develop a model for optimizing railway maintenance planning. The objective is to implement an efficient algorithm that can be applied in real-world networks. Cracks that develop on the rail surface, such as 'head checks', can lead to catastrophic failures if not promptly addressed. To mitigate this risk, preventive grinding is applied. In this work, the objective is to optimize the frequency of preventive grinding interventions for each geometric element of the railway, ensuring both rail safety and operational efficiency. The optimization model utilizes head check forecasts and existing interval scheduling data as inputs.

2024

A computational comparison of open-source branch-and-price solvers, Jules Schneuwly

Supervision: Lea Ricard, Fabian Torres, Michel Bierlaire
Column generation algorithms are relevant for addressing problems featuring a large number of decision variables (i.e., columns), commonly encountered in transportation and logistics problems such as vehicle routing and scheduling of staff or resources. When these optimization problems involve integrality constraints, column generation algorithms can be integrated into a branch-and-bound tree. This solution method is also referred to as branch-and-price. Historically, such algorithms have been predominantly developed within closed-source solvers, which raises issues regarding the comparability and reproducibility of computational experiments. Recently, the academic community has introduced open-source branch-and-price solvers to address these concerns. This project aims to compare two such open-source solvers in terms of computational time and flexibility across various families of mixed-integer problems (MIPs). The selected open-source solvers are: