Portrait de Aaron Courville

Aaron Courville

Membre académique principal
Chaire en IA Canada-CIFAR
Professeur titulaire, Université de Montréal, Département d'informatique et de recherche opérationnelle
Sujets de recherche
Apprentissage de représentations
Apprentissage par renforcement
Apprentissage profond
Communication efficace dans un jeu de somme générale
Modèles génératifs
Systèmes multi-agents
Théorie des jeux
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 et Directeur scientifique à IVADO. 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. 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, à l'apprentissage par renforcement multi-agents, aux modèles génératifs profonds et au raisonnement.

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, Meta, 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
Doctorat - UdeM
Doctorat - UdeM
Doctorat - UdeM
Doctorat - UdeM
Superviseur⋅e principal⋅e :
Doctorat - UdeM
Superviseur⋅e principal⋅e :
Doctorat - UdeM
Co-superviseur⋅e :
Collaborateur·rice de recherche - UdeM
Maîtrise recherche - UdeM
Maîtrise recherche - UdeM
Doctorat - UdeM
Superviseur⋅e principal⋅e :
Doctorat - UdeM
Superviseur⋅e principal⋅e :
Doctorat - UdeM
Doctorat - UdeM
Co-superviseur⋅e :

Publications

Learning Silicon Dopant Transitions in Graphene using Scanning Transmission Electron Microscopy
Joshua Greaves
Kevin Roccapriore
Ekin Dogus Cubuk
Bellemare Marc-Emmanuel
Sergei Kalinin
Igor Mordatch
We introduce a machine learning approach to determine the transition rates of silicon atoms on a single layer of carbon atoms, when stimulat… (voir plus)ed by the electron beam of a scanning transmission electron microscope (STEM). Our method is data-centric, leveraging data collected on a STEM. The data samples are processed and filtered to produce symbolic representations, which we use to train a neural network to predict transition rates. These rates are then applied to guide a single silicon atom throughout the lattice to pre-determined target destinations. We present empirical analyses that demonstrate the efficacy and generality of our approach.
Sparse Universal Transformer
Zhenfang Chen
Chuang Gan
The Universal Transformer (UT) is a variant of the Transformer that shares parameters across its layers and is Turing-complete under certain… (voir plus) assumptions. Empirical evidence also shows that UTs have better compositional generalization than Vanilla Transformers (VTs) in formal language tasks. The parameter-sharing also affords it better parameter efficiency than VTs. Despite its many advantages, most state-of-the-art NLP systems use VTs as their backbone model instead of UTs. This is mainly because scaling UT parameters is more compute and memory intensive than scaling up a VT. This paper proposes the Sparse Universal Transformer (SUT), which leverages Sparse Mixture of Experts (SMoE) to reduce UT's computation complexity while retaining its parameter efficiency and generalization ability. Experiments show that SUT combines the best of both worlds, achieving strong generalization results on formal language tasks (Logical inference and CFQ) and impressive parameter and computation efficiency on standard natural language benchmarks like WMT'14.
Double Gumbel Q-Learning
Group Robust Classification Without Any Group Information
Joao Monteiro
Pau Rodríguez
Empirical risk minimization (ERM) is sensitive to spurious correlations in the training data, which poses a significant risk when deploying … (voir plus)systems trained under this paradigm in high-stake applications. While the existing literature focuses on maximizing group-balanced or worst-group accuracy, estimating these accuracies is hindered by costly bias annotations. This study contends that current bias-unsupervised approaches to group robustness continue to rely on group information to achieve optimal performance. Firstly, these methods implicitly assume that all group combinations are represented during training. To illustrate this, we introduce a systematic generalization task on the MPI3D dataset and discover that current algorithms fail to improve the ERM baseline when combinations of observed attribute values are missing. Secondly, bias labels are still crucial for effective model selection, restricting the practicality of these methods in real-world scenarios. To address these limitations, we propose a revised methodology for training and validating debiased models in an entirely bias-unsupervised manner. We achieve this by employing pretrained self-supervised models to reliably extract bias information, which enables the integration of a logit adjustment training loss with our validation criterion. Our empirical analysis on synthetic and real-world tasks provides evidence that our approach overcomes the identified challenges and consistently enhances robust accuracy, attaining performance which is competitive with or outperforms that of state-of-the-art methods, which, conversely, rely on bias labels for validation.
Improving Compositional Generalization using Iterated Learning and Simplicial Embeddings
Samuel Lavoie
Danica J. Sutherland
Compositional generalization, the ability of an agent to generalize to unseen combinations of latent factors, is easy for humans but hard fo… (voir plus)r deep neural networks. A line of research in cognitive science has hypothesized a process, ``iterated learning,'' to help explain how human language developed this ability; the theory rests on simultaneous pressures towards compressibility (when an ignorant agent learns from an informed one) and expressivity (when it uses the representation for downstream tasks). Inspired by this process, we propose to improve the compositional generalization of deep networks by using iterated learning on models with simplicial embeddings, which can approximately discretize representations. This approach is further motivated by an analysis of compositionality based on Kolmogorov complexity. We show that this combination of changes improves compositional generalization over other approaches, demonstrating these improvements both on vision tasks with well-understood latent factors and on real molecular graph prediction tasks where the latent structure is unknown.
Language Model Alignment with Elastic Reset
Finetuning language models with reinforcement learning (RL), e.g. from human feedback (HF), is a prominent method for alignment. But optimiz… (voir plus)ing against a reward model can improve on reward while degrading performance in other areas, a phenomenon known as reward hacking, alignment tax, or language drift. First, we argue that commonly-used test metrics are insufficient and instead measure how different algorithms tradeoff between reward and drift. The standard method modified the reward with a Kullback-Lieber (KL) penalty between the online and initial model. We propose Elastic Reset, a new algorithm that achieves higher reward with less drift without explicitly modifying the training objective. We periodically reset the online model to an exponentially moving average (EMA) of itself, then reset the EMA model to the initial model. Through the use of an EMA, our model recovers quickly after resets and achieves higher reward with less drift in the same number of steps. We demonstrate that fine-tuning language models with Elastic Reset leads to state-of-the-art performance on a small scale pivot-translation benchmark, outperforms all baselines in a medium-scale RLHF-like IMDB mock sentiment task and leads to a more performant and more aligned technical QA chatbot with LLaMA-7B. Code available at github.com/mnoukhov/elastic-reset.
Let the Flows Tell: Solving Graph Combinatorial Optimization Problems with GFlowNets
Discovering the Electron Beam Induced Transition Rates for Silicon Dopants in Graphene with Deep Neural Networks in the STEM
Kevin M Roccapriore
Joshua Greaves
Colton Bishop
Maxim Ziatdinov
Igor Mordatch
Ekin D Cubuk
Bellemare Marc-Emmanuel
Sergei V Kalinin
Journal Article Discovering the Electron Beam Induced Transition Rates for Silicon Dopants in Graphene with Deep Neural Networks in the STEM… (voir plus) Get access Kevin M Roccapriore, Kevin M Roccapriore Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, United States Search for other works by this author on: Oxford Academic Google Scholar Max Schwarzer, Max Schwarzer Mila - Québec AI Institute, Montréal, QC, CanadaDepartment of Computer Science and Operations Research, Université de Montréal, Montréal, QC, CanadaGoogle Research, Brain Team Search for other works by this author on: Oxford Academic Google Scholar Joshua Greaves, Joshua Greaves Google Research, Brain Team Search for other works by this author on: Oxford Academic Google Scholar Jesse Farebrother, Jesse Farebrother Mila - Québec AI Institute, Montréal, QC, CanadaGoogle Research, Brain TeamSchool of Computer Science, McGill University, Montréal, QC, Canada Search for other works by this author on: Oxford Academic Google Scholar Rishabh Agarwal, Rishabh Agarwal Mila - Québec AI Institute, Montréal, QC, CanadaDepartment of Computer Science and Operations Research, Université de Montréal, Montréal, QC, CanadaGoogle Research, Brain Team Search for other works by this author on: Oxford Academic Google Scholar Colton Bishop, Colton Bishop Google Research, Brain Team Search for other works by this author on: Oxford Academic Google Scholar Maxim Ziatdinov, Maxim Ziatdinov Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, United StatesComputational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States Search for other works by this author on: Oxford Academic Google Scholar Igor Mordatch, Igor Mordatch Google Research, Brain Team Search for other works by this author on: Oxford Academic Google Scholar Ekin D Cubuk, Ekin D Cubuk Google Research, Brain Team Search for other works by this author on: Oxford Academic Google Scholar Aaron Courville, Aaron Courville Mila - Québec AI Institute, Montréal, QC, CanadaDepartment of Computer Science and Operations Research, Université de Montréal, Montréal, QC, Canada Search for other works by this author on: Oxford Academic Google Scholar ... Show more Pablo Samuel Castro, Pablo Samuel Castro Google Research, Brain Team Search for other works by this author on: Oxford Academic Google Scholar Marc G Bellemare, Marc G Bellemare Mila - Québec AI Institute, Montréal, QC, CanadaGoogle Research, Brain TeamSchool of Computer Science, McGill University, Montréal, QC, Canada Search for other works by this author on: Oxford Academic Google Scholar Sergei V Kalinin Sergei V Kalinin Department of Materials Science and Engineering, University of Tennessee, Knoxville TN, United States Corresponding author: sergei2@utk.edu Search for other works by this author on: Oxford Academic Google Scholar Microscopy and Microanalysis, Volume 29, Issue Supplement_1, 1 August 2023, Pages 1932–1933, https://doi.org/10.1093/micmic/ozad067.1000 Published: 22 July 2023
Meta-Value Learning: a General Framework for Learning with Learning Awareness
Bigger, Better, Faster: Human-level Atari with human-level efficiency
Johan Obando-Ceron
Bellemare Marc-Emmanuel
We introduce a value-based RL agent, which we call BBF, that achieves super-human performance in the Atari 100K benchmark. BBF relies on sca… (voir plus)ling the neural networks used for value estimation, as well as a number of other design choices that enable this scaling in a sample-efficient manner. We conduct extensive analyses of these design choices and provide insights for future work. We end with a discussion about updating the goalposts for sample-efficient RL research on the ALE. We make our code and data publicly available at https://github.com/google-research/google-research/tree/master/bigger_better_faster.
Learning with Learning Awareness using Meta-Values
Generative Augmented Flow Networks
The Generative Flow Network is a probabilistic framework where an agent learns a stochastic policy for object generation, such that the prob… (voir plus)ability of generating an object is proportional to a given reward function. Its effectiveness has been shown in discovering high-quality and diverse solutions, compared to reward-maximizing reinforcement learning-based methods. Nonetheless, GFlowNets only learn from rewards of the terminal states, which can limit its applicability. Indeed, intermediate rewards play a critical role in learning, for example from intrinsic motivation to provide intermediate feedback even in particularly challenging sparse reward tasks. Inspired by this, we propose Generative Augmented Flow Networks (GAFlowNets), a novel learning framework to incorporate intermediate rewards into GFlowNets. We specify intermediate rewards by intrinsic motivation to tackle the exploration problem in sparse reward environments. GAFlowNets can leverage edge-based and state-based intrinsic rewards in a joint way to improve exploration. Based on extensive experiments on the GridWorld task, we demonstrate the effectiveness and efficiency of GAFlowNet in terms of convergence, performance, and diversity of solutions. We further show that GAFlowNet is scalable to a more complex and large-scale molecule generation domain, where it achieves consistent and significant performance improvement.