Portrait de Emmanuel Bengio

Emmanuel Bengio

Membre industriel associé
Scientifique en apprentissage automatique, Recursion
Sujets de recherche
Apprentissage par renforcement
Apprentissage profond
GFlowNets
Modèles génératifs
Modélisation moléculaire

Biographie

Emmanuel Bengio est chercheur en ML à Valence Labs/Recursion, où il travaille sur l'intersection des GFlowNets et de la découverte de médicaments. Il a fait son doctorat sous la direction de Joelle Pineau et Doina Precup à McGill/Mila - Institut québécois d'intelligence artificielle, en se concentrant sur la compréhension de la généralisation dans la RL profonde.

Publications

E VALUATING G ENERALIZATION IN GF LOW N ETS FOR M OLECULE D ESIGN
Andrei Cristian Nica
Moksh J. Jain
Cheng-Hao Liu
Maksym Korablyov
Michael M. Bronstein
Deep learning bears promise for drug discovery problems such as de novo molecular design. Generating data to train such models is a costly a… (voir plus)nd time-consuming process, given the need for wet-lab experiments or expensive simulations. This problem is compounded by the notorious data-hungriness of machine learning algorithms. In small molecule generation the recently proposed GFlowNet method has shown good performance in generating diverse high-scoring candidates, and has the interesting advantage of being an off-policy offline method. Finding an appropriate generalization evaluation metric for such models, one predictive of the desired search performance (i.e. finding high-scoring diverse candidates), will help guide online data collection for such an algorithm. In this work, we develop techniques for evaluating GFlowNet performance on a test set, and identify the most promising metric for predicting generalization. We present empirical results on several small-molecule design tasks in drug discovery, for several GFlowNet training setups, and we find a metric strongly correlated with diverse high-scoring batch generation. This metric should be used to identify the best generative model from which to sample batches of molecules to be evaluated.
Trajectory Balance: Improved Credit Assignment in GFlowNets
Nikolay Malkin
Moksh J. Jain
Chen Sun
Generative flow networks (GFlowNets) are a method for learning a stochastic policy for generating compositional objects, such as graphs or s… (voir plus)trings, from a given unnormalized density by sequences of actions, where many possible action sequences may lead to the same object. We find previously proposed learning objectives for GFlowNets, flow matching and detailed balance, which are analogous to temporal difference learning, to be prone to inefficient credit propagation across long action sequences. We thus propose a new learning objective for GFlowNets, trajectory balance, as a more efficient alternative to previously used objectives. We prove that any global minimizer of the trajectory balance objective can define a policy that samples exactly from the target distribution. In experiments on four distinct domains, we empirically demonstrate the benefits of the trajectory balance objective for GFlowNet convergence, diversity of generated samples, and robustness to long action sequences and large action spaces.
GFlowNet Foundations
Tristan Deleu
Edward J Hu
Salem Lahlou
Mo Tiwari
GFlowNet Foundations
Tristan Deleu
Edward J Hu
Salem Lahlou
Mo Tiwari
GFlowNet Foundations
Tristan Deleu
Edward J Hu
Salem Lahlou
Mo Tiwari
GFlowNet Foundations
Tristan Deleu
Edward J Hu
Salem Lahlou
Mo Tiwari
GFlowNet Foundations
Tristan Deleu
Edward J Hu
Salem Lahlou
Mo Tiwari
GFlowNet Foundations
Tristan Deleu
Edward J Hu
Salem Lahlou
Mo Tiwari
GFlowNet Foundations
Tristan Deleu
Edward J Hu
Salem Lahlou
Mo Tiwari
GFlowNet Foundations
Tristan Deleu
Edward J Hu
Salem Lahlou
Mo Tiwari
GFlowNet Foundations
Tristan Deleu
Edward J Hu
Salem Lahlou
Mo Tiwari
Generative Flow Networks (GFlowNets) have been introduced as a method to sample a diverse set of candidates in an active learning context, w… (voir plus)ith a training objective that makes them approximately sample in proportion to a given reward function. In this paper, we show a number of additional theoretical properties of GFlowNets. They can be used to estimate joint probability distributions and the corresponding marginal distributions where some variables are unspecified and, of particular interest, can represent distributions over composite objects like sets and graphs. GFlowNets amortize the work typically done by computationally expensive MCMC methods in a single but trained generative pass. They could also be used to estimate partition functions and free energies, conditional probabilities of supersets (supergraphs) given a subset (subgraph), as well as marginal distributions over all supersets (supergraphs) of a given set (graph). We introduce variations enabling the estimation of entropy and mutual information, sampling from a Pareto frontier, connections to reward-maximizing policies, and extensions to stochastic environments, continuous actions and modular energy functions.
GFlowNet Foundations
Tristan Deleu
Edward J Hu
Salem Lahlou
Mo Tiwari