Portrait de Aaron Courville

Aaron Courville

Membre académique principal
Chaire en IA Canada-CIFAR
Professeur agrégé, Université de Montréal, Département d'informatique et de recherche opérationnelle
Sujets de recherche
Apprentissage de représentations
Apprentissage par renforcement
Apprentissage profond
Modèles génératifs
Traitement du langage naturel
Vision par ordinateur

Biographie

Aaron Courville est professeur au Département d'informatique et de recherche opérationnelle (DIRO) de l'Université de Montréal. Il a obtenu son doctorat au Robotics Institute de l'Université Carnegie Mellon. Il est l'un des premiers contributeurs à l'apprentissage profond, membre fondateur de Mila – Institut québécois d’intelligence artificielle et membre du programme Apprentissage automatique, apprentissage biologique de l'Institut canadien de recherches avancées (CIFAR). Avec Ian Goodfellow et Yoshua Bengio, il a coécrit le manuel de référence sur l'apprentissage profond. Ses recherches actuelles portent sur le développement de modèles et de méthodes d'apprentissage profond. Il s'intéresse particulièrement à l'apprentissage par renforcement, aux modèles génératifs profonds et à l'apprentissage multimodal avec des applications telles que la vision par ordinateur et le traitement du langage naturel. Aaron Courville est titulaire d'une chaire en IA Canada-CIFAR et d'une Chaire de recherche du Canada (CRC) en généralisation systématique. Ses recherches ont été soutenues en partie par Microsoft Research, Samsung, Hitachi, Sony (bourse de recherche) et Google (bourse de recherche ciblée).

Étudiants actuels

Doctorat - UdeM
Co-superviseur⋅e :
Doctorat - UdeM
Superviseur⋅e principal⋅e :
Maîtrise recherche - Université de Montréal
Maîtrise recherche - UdeM
Maîtrise professionnelle - UdeM
Doctorat - UdeM
Doctorat - UdeM
Doctorat - UdeM
Superviseur⋅e principal⋅e :
Doctorat - UdeM
Co-superviseur⋅e :
Doctorat - UdeM
Superviseur⋅e principal⋅e :
Doctorat - UdeM
Co-superviseur⋅e :
Maîtrise recherche - UdeM
Doctorat - UdeM
Superviseur⋅e principal⋅e :
Maîtrise recherche - UdeM
Superviseur⋅e principal⋅e :
Doctorat - UdeM
Superviseur⋅e principal⋅e :
Doctorat - UdeM
Superviseur⋅e principal⋅e :
Doctorat - UdeM
Doctorat - UdeM
Co-superviseur⋅e :
Doctorat - UdeM
Superviseur⋅e principal⋅e :

Publications

Unifying Likelihood-free Inference with Black-box Sequence Design and Beyond
Dinghuai Zhang
Jie Fu
NU-GAN: High resolution neural upsampling with GAN
Rithesh Kumar
Kundan Kumar
Vicki Anand
In this paper, we propose NU-GAN, a new method for resampling audio from lower to higher sampling rates (upsampling). Audio upsampling is an… (voir plus) important problem since productionizing generative speech technology requires operating at high sampling rates. Such applications use audio at a resolution of 44.1 kHz or 48 kHz, whereas current speech synthesis methods are equipped to handle a maximum of 24 kHz resolution. NU-GAN takes a leap towards solving audio upsampling as a separate component in the text-to-speech (TTS) pipeline by leveraging techniques for audio generation using GANs. ABX preference tests indicate that our NU-GAN resampler is capable of resampling 22 kHz to 44.1 kHz audio that is distinguishable from original audio only 7.4% higher than random chance for single speaker dataset, and 10.8% higher than chance for multi-speaker dataset.
Explicitly Modeling Syntax in Language Model improves Generalization
Syntax is fundamental to our thinking about language. Although neural networks are very successful in many tasks, they do not explicitly mod… (voir plus)el syntactic structure. Failing to capture the structure of inputs could lead to generalization problems and over-parametrization. In the present work, we propose a new syntax-aware language model: Syntactic Ordered Memory (SOM). The model explicitly models the structure with a one-step look-ahead parser and maintains the conditional probability setting of the standard language model. Experiments show that SOM can achieve strong results in language modeling and syntactic generalization tests, while using fewer parameters then other models.
A Large-Scale, Open-Domain, Mixed-Interface Dialogue-Based ITS for STEM
Iulian V. Serban
Varun Gupta
Ekaterina Kochmar
Dung D. Vu
Robert Belfer
Stochastic Neural Network with Kronecker Flow
Chin-Wei Huang
Ahmed Touati
Alexandre Lacoste
Recent advances in variational inference enable the modelling of highly structured joint distributions, but are limited in their capacity to… (voir plus) scale to the high-dimensional setting of stochastic neural networks. This limitation motivates a need for scalable parameterizations of the noise generation process, in a manner that adequately captures the dependencies among the various parameters. In this work, we address this need and present the Kronecker Flow, a generalization of the Kronecker product to invertible mappings designed for stochastic neural networks. We apply our method to variational Bayesian neural networks on predictive tasks, PAC-Bayes generalization bound estimation, and approximate Thompson sampling in contextual bandits. In all setups, our methods prove to be competitive with existing methods and better than the baselines.
Learning Classical Planning Transition Functions by Deep Neural Networks
Michaela Urbanovská
Ian G Goodfellow
Université de Montréal Balancing Signals for Semi-Supervised Sequence Learning
Training recurrent neural networks (RNNs) on long sequences using backpropagation through time (BPTT) remains a fundamental challenge. It ha… (voir plus)s been shown that adding a local unsupervised loss term into the optimization objective makes the training of RNNs on long sequences more effective. While the importance of an unsupervised task can in principle be controlled by a coefficient in the objective function, the gradients with respect to the unsupervised loss term still influence all the hidden state dimensions, which might cause important information about the supervised task to be degraded or erased. Compared to existing semi-supervised sequence learning methods, this thesis focuses upon a traditionally overlooked mechanism – an architecture with explicitly designed private and shared hidden units designed to mitigate the detrimental influence of the auxiliary unsupervised loss over the main supervised task. We achieve this by dividing the RNN hidden space into a private space for the supervised task or a shared space for both the supervised and unsupervised tasks. We present extensive experiments with the proposed framework on several long sequence modeling benchmark datasets. Results indicate that the proposed framework can yield performance gains in RNN models where long term dependencies are notoriously challenging to deal with.
CLOSURE: Assessing Systematic Generalization of CLEVR Models
Harm de Vries
Shikhar Murty
Philippe Beaudoin
Icentia11K: An Unsupervised Representation Learning Dataset for Arrhythmia Subtype Discovery
Shawn Tan
Guillaume Androz
Ahmad Chamseddine
Pierre Fecteau
Joseph Paul Cohen
We release the largest public ECG dataset of continuous raw signals for representation learning containing 11 thousand patients and 2 billio… (voir plus)n labelled beats. Our goal is to enable semi-supervised ECG models to be made as well as to discover unknown subtypes of arrhythmia and anomalous ECG signal events. To this end, we propose an unsupervised representation learning task, evaluated in a semi-supervised fashion. We provide a set of baselines for different feature extractors that can be built upon. Additionally, we perform qualitative evaluations on results from PCA embeddings, where we identify some clustering of known subtypes indicating the potential for representation learning in arrhythmia sub-type discovery.
Stochastic Neural Network with Kronecker Flow
Chin-Wei Huang
Ahmed Touati
Alexandre Lacoste
Recent advances in variational inference enable the modelling of highly structured joint distributions, but are limited in their capacity to… (voir plus) scale to the high-dimensional setting of stochastic neural networks. This limitation motivates a need for scalable parameterizations of the noise generation process, in a manner that adequately captures the dependencies among the various parameters. In this work, we address this need and present the Kronecker Flow, a generalization of the Kronecker product to invertible mappings designed for stochastic neural networks. We apply our method to variational Bayesian neural networks on predictive tasks, PAC-Bayes generalization bound estimation, and approximate Thompson sampling in contextual bandits. In all setups, our methods prove to be competitive with existing methods and better than the baselines.
Representation Mixing for TTS Synthesis
Kyle Kastner
Joao Felipe Santos
Recent character and phoneme-based parametric TTS systems using deep learning have shown strong performance in natural speech generation. Ho… (voir plus)wever, the choice between character or phoneme input can create serious limitations for practical deployment, as direct control of pronunciation is crucial in certain cases. We demonstrate a simple method for combining multiple types of linguistic information in a single encoder, named representation mixing, enabling flexible choice between character, phoneme, or mixed representations during inference. Experiments and user studies on a public audiobook corpus show the efficacy of our approach.
Maximum Entropy Generators for Energy-Based Models
Rithesh Kumar
Anirudh Goyal
Maximum likelihood estimation of energy-based models is a challenging problem due to the intractability of the log-likelihood gradient. In t… (voir plus)his work, we propose learning both the energy function and an amortized approximate sampling mechanism using a neural generator network, which provides an efficient approximation of the log-likelihood gradient. The resulting objective requires maximizing entropy of the generated samples, which we perform using recently proposed nonparametric mutual information estimators. Finally, to stabilize the resulting adversarial game, we use a zero-centered gradient penalty derived as a necessary condition from the score matching literature. The proposed technique can generate sharp images with Inception and FID scores competitive with recent GAN techniques, does not suffer from mode collapse, and is competitive with state-of-the-art anomaly detection techniques.