Portrait de Doina Precup

Doina Precup

Membre académique principal
Chaire en IA Canada-CIFAR
Professeure agrégée, McGill University, École d'informatique
Chef d'équipe de recherche, Google DeepMind
Sujets de recherche
Apprentissage automatique médical
Apprentissage par renforcement
Modèles probabilistes
Modélisation moléculaire
Raisonnement

Biographie

Doina Precup enseigne à l'Université McGill tout en menant des recherches fondamentales sur l'apprentissage par renforcement, notamment les applications de l'IA dans des domaines ayant des répercussions sociales, tels que les soins de santé. Elle s'intéresse à la prise de décision automatique dans des situations d'incertitude élevée.

Elle est membre de l'Institut canadien de recherches avancées (CIFAR) et de l'Association pour l'avancement de l'intelligence artificielle (AAAI), et dirige le bureau montréalais de DeepMind.

Ses spécialités sont les suivantes : intelligence artificielle, apprentissage machine, apprentissage par renforcement, raisonnement et planification sous incertitude, applications.

Étudiants actuels

Stagiaire de recherche - McGill
Collaborateur·rice alumni - McGill
Co-superviseur⋅e :
Collaborateur·rice alumni - McGill
Doctorat - McGill
Co-superviseur⋅e :
Doctorat - McGill
Superviseur⋅e principal⋅e :
Maîtrise recherche - McGill
Superviseur⋅e principal⋅e :
Collaborateur·rice de recherche - McGill
Co-superviseur⋅e :
Collaborateur·rice de recherche - UdeM
Doctorat - McGill
Superviseur⋅e principal⋅e :
Doctorat - McGill
Superviseur⋅e principal⋅e :
Collaborateur·rice de recherche - Birla Institute of Technology
Maîtrise recherche - McGill
Doctorat - McGill
Collaborateur·rice alumni - McGill
Maîtrise recherche - McGill
Doctorat - Polytechnique
Postdoctorat - McGill
Collaborateur·rice alumni - McGill
Collaborateur·rice alumni - McGill
Doctorat - McGill
Superviseur⋅e principal⋅e :
Doctorat - McGill
Collaborateur·rice alumni - McGill
Maîtrise recherche - McGill
Superviseur⋅e principal⋅e :
Collaborateur·rice de recherche - McGill
Co-superviseur⋅e :
Doctorat - UdeM
Co-superviseur⋅e :
Doctorat - McGill
Co-superviseur⋅e :
Stagiaire de recherche - McGill
Doctorat - McGill
Superviseur⋅e principal⋅e :
Doctorat - McGill
Co-superviseur⋅e :
Doctorat - McGill
Co-superviseur⋅e :
Doctorat - McGill
Co-superviseur⋅e :
Stagiaire de recherche - McGill
Doctorat - McGill
Maîtrise recherche - McGill
Co-superviseur⋅e :
Doctorat - McGill
Superviseur⋅e principal⋅e :
Doctorat - McGill
Collaborateur·rice alumni - McGill
Co-superviseur⋅e :

Publications

1. Searching for Big-Oh in the Data: Inferring Asymptotic Complexity from Experiments
Catherine McGeoch
Peter Sanders 0001
Rudolf Fleischer
Paul R. Cohen
Avoidance Learning Using Observational Reinforcement Learning
David Venuto
Léonard Boussioux
Junhao Wang
Rola Dali
Imitation learning seeks to learn an expert policy from sampled demonstrations. However, in the real world, it is often difficult to find a … (voir plus)perfect expert and avoiding dangerous behaviors becomes relevant for safety reasons. We present the idea of \textit{learning to avoid}, an objective opposite to imitation learning in some sense, where an agent learns to avoid a demonstrator policy given an environment. We define avoidance learning as the process of optimizing the agent's reward while avoiding dangerous behaviors given by a demonstrator. In this work we develop a framework of avoidance learning by defining a suitable objective function for these problems which involves the \emph{distance} of state occupancy distributions of the expert and demonstrator policies. We use density estimates for state occupancy measures and use the aforementioned distance as the reward bonus for avoiding the demonstrator. We validate our theory with experiments using a wide range of partially observable environments. Experimental results show that we are able to improve sample efficiency during training compared to state of the art policy optimization and safety methods.
Break the Ceiling: Stronger Multi-scale Deep Graph Convolutional Networks
Mingde Zhao
Xiao-Wen Chang
Recently, neural network based approaches have achieved significant improvement for solving large, complex, graph-structured problems. Howev… (voir plus)er, their bottlenecks still need to be addressed, and the advantages of multi-scale information and deep architectures have not been sufficiently exploited. In this paper, we theoretically analyze how existing Graph Convolutional Networks (GCNs) have limited expressive power due to the constraint of the activation functions and their architectures. We generalize spectral graph convolution and deep GCN in block Krylov subspace forms and devise two architectures, both with the potential to be scaled deeper but each making use of the multi-scale information in different ways. We further show that the equivalence of these two architectures can be established under certain conditions. On several node classification tasks, with or without the help of validation, the two new architectures achieve better performance compared to many state-of-the-art methods.
Community size effect in artificial learning systems
Olivier Tieleman
Angeliki Lazaridou
Shibl Mourad
Charles Blundell
Motivated by theories of language and communication that explain why communities with large numbers of speakers have, on average, simpler la… (voir plus)nguages with more regularity, we cast the representation learning problem in terms of learning to communicate . Our starting point sees the traditional autoencoder setup as a single encoder with a fixed decoder partner that must learn to communicate. Generalizing from there, we introduce community -based autoencoders in which multiple encoders and decoders collectively learn representations by being randomly paired up on successive training iterations. We find that increasing community sizes reduce idiosyncrasies in the learned codes, resulting in representations that better encode concept categories and correlate with human feature norms.
Connecting Weighted Automata and Recurrent Neural Networks through Spectral Learning ( Supplementary Material ) A Proofs
More precisely, the WFA A = (α, {A}σ∈Σ,Ω) with n states and the linear 2-RNN M = (α,A,Ω) with n hidden units, where A ∈ Rn×Σ×n … (voir plus)is defined by A:,σ,: = A for all σ ∈ Σ, are such that fA(σ1σ2 · · ·σk) = fM (x1,x2, · · · ,xk) for all sequences of input symbols σ1, · · · , σk ∈ Σ, where for each i ∈ [k] the input vector xi ∈ RΣ is the one-hot encoding of the symbol σi. Proof. We first show by induction on k that, for any sequence σ1 · · ·σk ∈ Σ∗, the hidden state hk computed by M (see Eq. (1)) on the corresponding one-hot encoded sequence x1, · · · ,xk ∈ R satisfies hk = (A1 · · ·Ak )>α. The case k = 0 is immediate. Suppose the result true for sequences of length up to k. One can check easily check that A •2 xi = Ai for any index i. Using the induction hypothesis it then follows that hk+1 = A •1 hk •2 xk+1 = Ak+1 •1 hk = (Ak+1)hk = (Aσk+1)>(Aσ1 · · ·Ak )>α = (A1 · · ·Aσk+1)>α.
Data-driven Chance Constrained Programming based Electric Vehicle Penetration Analysis
Tracy Can Cui
Benoit Boulet
Transportation electrification has been growing rapidly in recent years. The adoption of electric vehicles (EVs) could help to release the d… (voir plus)ependency on oil and reduce greenhouse gas emission. However, the increasing EV adoption will also impose a high demand on the power grid and may jeopardize the grid network infrastructures. For certain high EV penetration areas, the EV charging demand may lead to transformer overloading at peak hours which makes the maximal EV penetration analysis an urgent problem to solve. This paper proposes a data-driven chance constrained programming based framework for maximal EV penetration analysis. Simulation results are presented for a real-world neighborhood level network. The proposed framework could serve as a guidance for utility companies to schedule infrastructure upgrades.
An Empirical Study of Batch Normalization and Group Normalization in Conditional Computation
Batch normalization has been widely used to improve optimization in deep neural networks. While the uncertainty in batch statistics can act … (voir plus)as a regularizer, using these dataset statistics specific to the training set impairs generalization in certain tasks. Recently, alternative methods for normalizing feature activations in neural networks have been proposed. Among them, group normalization has been shown to yield similar, in some domains even superior performance to batch normalization. All these methods utilize a learned affine transformation after the normalization operation to increase representational power. Methods used in conditional computation define the parameters of these transformations as learnable functions of conditioning information. In this work, we study whether and where the conditional formulation of group normalization can improve generalization compared to conditional batch normalization. We evaluate performances on the tasks of visual question answering, few-shot learning, and conditional image generation.
Hindsight Credit Assignment
Anna Harutyunyan
Will Dabney
Mohammad Gheshlaghi Azar
Bilal Piot
Nicolas Heess
Hado van Hasselt
Greg Wayne
Satinder Singh
Remi Munos
Learning Reliable Policies in the Bandit Setting with Application to Adaptive Clinical Trials
The stochastic multi-armed bandit problem is a well-known model for studying the explorationexploitation trade-off. It has significant possi… (voir plus)ble applications in adaptive clinical trials, which allow for a dynamic change of patient allocation ratios. However, most bandit learning algorithms are designed with the goal of minimizing the expected regret. While this approach is useful in many areas, in clinical trials, it can be sensitive to outlier data especially when the sample size is small. In this article, we propose a modification of the BESA algorithm [Baransi, Maillard, and Mannor, 2014] which takes into account the variance in the action outcomes in addition to the mean. We present a regret bound for our approach and evaluate it empirically both on synthetic problems as well as on a dataset form the clinical trial literature. Our approach compares favorably to a suite of standard bandit algorithms.
Learning representations of Logical Formulae using Graph Neural Networks
Eser Aygün
Shibl Mourad
Pushmeet Kohli
We explore the use of Graph Neural Networks(GNNs) for learning representations of propositional and first-order logical formulae. Tradition… (voir plus)al non-graphical based approaches like CNNs and LSTMs do not exploit invariant properties like variable renaming and order invariance predominantly present in logical formulae. In this work, we explicitly try to encode these logical invariances using GNNs. We use the task of entailment proposed in Evans et al. [2018] for propositional logic. We also explore our approach for the task of proof length prediction in first-order logic. We use the Mizar-40 dataset to evaluate several representation learning approaches for proof length prediction task. We observe that GNNs significantly outperform the other traditional approaches on both these tasks.
Meta-Learning State-based Eligibility Traces for More Sample-Efficient Policy Evaluation
Mingde Zhao
Xiao-Wen Chang
Temporal-Difference (TD) learning is a standard and very successful reinforcement learning approach, at the core of both algorithms that lea… (voir plus)rn the value of a given policy, as well as algorithms which learn how to improve policies. TD-learning with eligibility traces provides a way to boost sample efficiency by temporal credit assignment, i.e. deciding which portion of a reward should be assigned to predecessor states that occurred at different previous times, controlled by a parameter
Prediction of Disease Progression in Multiple Sclerosis Patients using Deep Learning Analysis of MRI Data
Adrian Tousignant
Paul Lemaitre
Douglas L. Arnold