Search Results for author: Thibaut Vidal

Found 26 papers, 16 papers with code

Trained Random Forests Completely Reveal your Dataset

1 code implementation29 Feb 2024 Julien Ferry, Ricardo Fukasawa, Timothée Pascal, Thibaut Vidal

Even with bootstrap aggregation, the majority of the data can also be reconstructed.

Reconstruction Attack

Contextual Stochastic Vehicle Routing with Time Windows

no code implementations10 Feb 2024 Breno Serrano, Alexandre M. Florio, Stefan Minner, Maximilian Schiffer, Thibaut Vidal

We study the vehicle routing problem with time windows (VRPTW) and stochastic travel times, in which the decision-maker observes related contextual information, represented as feature variables, before making routing decisions.

A Survey of Contextual Optimization Methods for Decision Making under Uncertainty

no code implementations17 Jun 2023 Utsav Sadana, Abhilash Chenreddy, Erick Delage, Alexandre Forel, Emma Frejinger, Thibaut Vidal

Recently there has been a surge of interest in operations research (OR) and the machine learning (ML) community in combining prediction algorithms and optimization techniques to solve decision-making problems in the face of uncertainty.

Decision Making Decision Making Under Uncertainty

Learning-based Online Optimization for Autonomous Mobility-on-Demand Fleet Control

1 code implementation8 Feb 2023 Kai Jungel, Axel Parmentier, Maximilian Schiffer, Thibaut Vidal

Autonomous mobility-on-demand systems are a viable alternative to mitigate many transportation-related externalities in cities, such as rising vehicle volumes in urban areas and transportation-related pollution.

Combinatorial Optimization Model Predictive Control

Regularization and Optimization in Model-Based Clustering

1 code implementation5 Feb 2023 Raphael Araujo Sampaio, Joaquim Dias Garcia, Marcus Poggi, Thibaut Vidal

We develop more effective optimization algorithms for general GMMs, and we combine these algorithms with regularization strategies that avoid overfitting.

Clustering

Explainable Data-Driven Optimization: From Context to Decision and Back Again

1 code implementation24 Jan 2023 Alexandre Forel, Axel Parmentier, Thibaut Vidal

Data-driven optimization uses contextual information and machine learning algorithms to find solutions to decision problems with uncertain parameters.

counterfactual Counterfactual Explanation +1

Bilevel Optimization for Feature Selection in the Data-Driven Newsvendor Problem

no code implementations12 Sep 2022 Breno Serrano, Stefan Minner, Maximilian Schiffer, Thibaut Vidal

The lower-level problem learns the optimal coefficients of the decision function on a training set, using only the features selected by the upper-level.

Bilevel Optimization Explainable Models +1

Neural Networks for Local Search and Crossover in Vehicle Routing: A Possible Overkill?

no code implementations9 Sep 2022 Ítalo Santana, Andrea Lodi, Thibaut Vidal

Extensive research has been conducted, over recent years, on various ways of enhancing heuristic search for combinatorial optimization problems with machine learning algorithms.

Combinatorial Optimization

Support Vector Machines with the Hard-Margin Loss: Optimal Training via Combinatorial Benders' Cuts

1 code implementation15 Jul 2022 Ítalo Santana, Breno Serrano, Maximilian Schiffer, Thibaut Vidal

The classical hinge-loss support vector machines (SVMs) model is sensitive to outlier observations due to the unboundedness of its loss function.

Optimal Decision Diagrams for Classification

no code implementations28 May 2022 Alexandre M. Florio, Pedro Martins, Maximilian Schiffer, Thiago Serra, Thibaut Vidal

Decision diagrams for classification have some notable advantages over decision trees, as their internal connections can be determined at training time and their width is not bound to grow exponentially with their depth.

Classification Fairness

Don't Explain Noise: Robust Counterfactuals for Randomized Ensembles

1 code implementation27 May 2022 Alexandre Forel, Axel Parmentier, Thibaut Vidal

Counterfactual explanations describe how to modify a feature vector in order to flip the outcome of a trained classifier.

counterfactual valid

Optimal Counterfactual Explanations in Tree Ensembles

1 code implementation11 Jun 2021 Axel Parmentier, Thibaut Vidal

Counterfactual explanations are usually generated through heuristics that are sensitive to the search's initial conditions.

counterfactual Counterfactual Explanation +1

Semi-Supervised Clustering with Inaccurate Pairwise Annotations

1 code implementation5 Apr 2021 Daniel Gribel, Michel Gendreau, Thibaut Vidal

Pairwise relational information is a useful way of providing partial supervision in domains where class labels are difficult to acquire.

Clustering Stochastic Block Model

Community Detection in the Stochastic Block Model by Mixed Integer Programming

1 code implementation26 Jan 2021 Breno Serrano, Thibaut Vidal

The standard approach of community detection based on the DCSBM is to search for the model parameters that are the most likely to have produced the observed network data through maximum likelihood estimation (MLE).

Community Detection Stochastic Block Model

Hybrid Genetic Search for the CVRP: Open-Source Implementation and SWAP* Neighborhood

2 code implementations23 Nov 2020 Thibaut Vidal

The vehicle routing problem is one of the most studied combinatorial optimization topics, due to its practical importance and methodological interest.

Combinatorial Optimization Efficient Exploration

Assortative-Constrained Stochastic Block Models

1 code implementation21 Apr 2020 Daniel Gribel, Thibaut Vidal, Michel Gendreau

Stochastic block models (SBMs) are often used to find assortative community structures in networks, such that the probability of connections within communities is higher than in between communities.

Community Detection Stochastic Block Model

Born-Again Tree Ensembles

1 code implementation ICML 2020 Thibaut Vidal, Toni Pacheco, Maximilian Schiffer

The use of machine learning algorithms in finance, medicine, and criminal justice can deeply impact human lives.

BIG-bench Machine Learning Interpretable Machine Learning

PILS: Exploring high-order neighborhoods by pattern mining and injection

1 code implementation24 Dec 2019 Florian Arnold, Ítalo Santana, Kenneth Sörensen, Thibaut Vidal

During the local search, each pattern is used to define one move in which 1) incompatible edges are disconnected, 2) the edges defined by the pattern are reconnected, and 3) the remaining solution fragments are optimally reconnected.

Vocal Bursts Intensity Prediction

A simple and effective hybrid genetic search for the job sequencing and tool switching problem

1 code implementation10 Oct 2019 Jordana Mecler, Anand Subramanian, Thibaut Vidal

The job sequencing and tool switching problem (SSP) has been extensively studied in the field of operations research, due to its practical relevance and methodological interest.

Management

A concise guide to existing and emerging vehicle routing problem variants

no code implementations16 Jun 2019 Thibaut Vidal, Gilbert Laporte, Piotr Matl

The diversity of applications has motivated the study of a myriad of problem variants with different attributes.

An Efficient Matheuristic for the Minimum-Weight Dominating Set Problem

no code implementations28 Aug 2018 Mayra Albuquerque, Thibaut Vidal

A minimum dominating set in a graph is a minimum set of vertices such that every vertex of the graph either belongs to it, or is adjacent to one vertex of this set.

HG-means: A scalable hybrid genetic algorithm for minimum sum-of-squares clustering

1 code implementation25 Apr 2018 Daniel Gribel, Thibaut Vidal

This may be related to differences of computational effort, or to the assumption that a near-optimal solution of the MSSC has only a marginal impact on clustering validity.

Clustering

Heuristics for vehicle routing problems: Sequence or set optimization?

no code implementations16 Mar 2018 Túlio A. M. Toffolo, Thibaut Vidal, Tony Wauters

We investigate a structural decomposition for the capacitated vehicle routing problem (CVRP) based on vehicle-to-customer "assignment" and visits "sequencing" decision variables.

Computational Efficiency

Large Neighborhood-Based Metaheuristic and Branch-and-Price for the Pickup and Delivery Problem with Split Loads

no code implementations18 Feb 2018 Matheus Nohra Haddad, Rafael Martinelli, Thibaut Vidal, Luiz Satoru Ochi, Simone Martins, Marcone Jamilson Freitas Souza, Richard Hartl

The core of the metaheuristic consists of a new large neighborhood search, which reduces the problem of finding the best insertion combination of a pickup and delivery pair into a route (with possible splits) to a resource-constrained shortest path and knapsack problem.

Technical Note: Split Algorithm in O(n) for the Capacitated Vehicle Routing Problem

1 code implementation11 Aug 2015 Thibaut Vidal

In the vehicle routing literature, Split is usually assimilated to the search for a shortest path in a directed acyclic graph $\mathcal{G}$ and solved in $O(nB)$ using Bellman's algorithm, where $n$ is the number of delivery points and $B$ is the average number of feasible routes that start with a given customer in the giant tour.

Data Structures and Algorithms

Hybrid Metaheuristics for the Clustered Vehicle Routing Problem

no code implementations26 Apr 2014 Thibaut Vidal, Maria Battarra, Anand Subramanian, Güneş Erdoǧan

The second algorithm is a Hybrid Genetic Search, for which the shortest Hamiltonian path between each pair of vertices within each cluster should be precomputed.

Cannot find the paper you are looking for? You can Submit a new open access paper.