Portrait de Laurent Charlin

Laurent Charlin

Membre académique principal
Chaire en IA Canada-CIFAR
Professeur agrégé, HEC Montréal, Département de Sciences de la décision
Professeur associé, Université de Montréal, Département d'informatique et de recherche opérationnelle
Sujets de recherche
Apprentissage de représentations
Apprentissage par renforcement
Apprentissage profond
Exploration des données
IA pour la science
Modèles génératifs
Modèles probabilistes
Recherche d'information
Réseaux de neurones en graphes
Systèmes de recommandation
Traitement du langage naturel

Biographie

Laurent Charlin est Directeur scientifique par intérim à Mila – Institut québécois d’intelligence artificielle, titulaire d’une chaire en IA Canada-CIFAR et professeur agrégé à HEC Montréal. Il est également membre principal à Mila.

Ses recherches portent sur le développement de nouveaux modèles d'apprentissage automatique pour aider à la prise de décision. Ses travaux récents concernent l'apprentissage à partir de données qui évoluent dans le temps. Il travaille également sur des applications dans des domaines tels que les systèmes de recommandation et l'optimisation.

Il est l'auteur de publications très citées sur les systèmes de dialogue (chatbots). Laurent Charlin a codéveloppé le Toronto Paper Matching System (TPMS), qui a été largement utilisé dans les conférences d'informatique pour faire correspondre les réviseur·euse·s aux articles. Il a également contribué à plusieurs MOOC récents, et a donné des conférences d'introduction et des interviews dans les médias pour contribuer au transfert de connaissances et améliorer la culture de l'IA.

Étudiants actuels

Maîtrise recherche - HEC
Postdoctorat - HEC
Co-superviseur⋅e :
Maîtrise recherche - HEC
Doctorat - UdeM
Doctorat - UdeM
Co-superviseur⋅e :
Maîtrise recherche - HEC
Doctorat - HEC
Superviseur⋅e principal⋅e :
Doctorat - Université Laval
Superviseur⋅e principal⋅e :
Doctorat - UdeM
Co-superviseur⋅e :
Doctorat - Concordia
Superviseur⋅e principal⋅e :
Collaborateur·rice alumni - UdeM
Postdoctorat - HEC
Co-superviseur⋅e :
Doctorat - UdeM
Doctorat - UdeM

Publications

Learnable Explicit Density for Continuous Latent Space and Variational Inference
Chin-Wei Huang
Ahmed Touati
Laurent Dinh
Michal Drozdzal
Mohammad Havaei
In this paper, we study two aspects of the variational autoencoder (VAE): the prior distribution over the latent variables and its correspon… (voir plus)ding posterior. First, we decompose the learning of VAEs into layerwise density estimation, and argue that having a flexible prior is beneficial to both sample generation and inference. Second, we analyze the family of inverse autoregressive flows (inverse AF) and show that with further improvement, inverse AF could be used as universal approximation to any complicated posterior. Our analysis results in a unified approach to parameterizing a VAE, without the need to restrict ourselves to use factorial Gaussians in the latent real space.
A Sparse Probabilistic Model of User Preference Data
Matthew J. A. Smith
A Hierarchical Latent Variable Encoder-Decoder Model for Generating Dialogues
Sequential data often possesses hierarchical structures with complex dependencies between sub-sequences, such as found between the utterance… (voir plus)s in a dialogue. To model these dependencies in a generative framework, we propose a neural network-based generative architecture, with stochastic latent variables that span a variable number of time steps. We apply the proposed model to the task of dialogue response generation and compare it with other recent neural-network architectures. We evaluate the model performance through a human evaluation study. The experiments demonstrate that our model improves upon recently proposed models and that the latent variables facilitate both the generation of meaningful, long and diverse responses and maintaining dialogue state.
Training End-to-End Dialogue Systems with the Ubuntu Dialogue Corpus
Ryan Thomas Lowe
Nissan Pow
Iulian V. Serban
Chia-Wei Liu
In this paper, we construct and train end-to-end neural network-based dialogue systems using an updated version of the recent Ubuntu Dialogu… (voir plus)e Corpus, a dataset containing almost 1 million multi-turn dialogues, with a total of over 7 million utterances and 100 million words. This dataset is interesting because of its size, long context lengths, and technical nature; thus, it can be used to train large models directly from data with minimal feature engineering, which can be both time consuming and expensive. We provide baselines  in two different environments: one where models are trained to maximize the log-likelihood of a generated utterance  conditioned on the context of the conversation, and one where models are trained to select the correct next response from a list of candidate responses. These are both evaluated on a recall task that we call Next Utterance Classification (NUC), as well as other generation-specific metrics. Finally, we provide a qualitative error analysis to help determine the most promising directions for future research on the Ubuntu  Dialogue Corpus, and for end-to-end dialogue systems in general.
A Hierarchical Latent Variable Encoder-Decoder Model for Generating Dialogues
Sequential data often possesses hierarchical structures with complex dependencies between sub-sequences, such as found between the utterance… (voir plus)s in a dialogue. To model these dependencies in a generative framework, we propose a neural network-based generative architecture, with stochastic latent variables that span a variable number of time steps. We apply the proposed model to the task of dialogue response generation and compare it with other recent neural-network architectures. We evaluate the model performance through a human evaluation study. The experiments demonstrate that our model improves upon recently proposed models and that the latent variables facilitate both the generation of meaningful, long and diverse responses and maintaining dialogue state.