Portrait de Narges Armanfard

Narges Armanfard

Membre académique associé
Professeure agrégée, McGill University, Département de génie électrique et informatique
Sujets de recherche
Apprentissage actif
Apprentissage automatique médical
Apprentissage de représentations
Apprentissage en ligne
Apprentissage multimodal
Apprentissage par renforcement
Apprentissage profond
Détection d'anomalies
IA appliquée
IA en santé
Méthodes de réduction de la dimensionnalité
Modèles génératifs
Réseaux de neurones en graphes
Vision par ordinateur

Biographie

Narges Armanfard (Ph. D., ing.) est la fondatrice et la chercheuse principale du laboratoire iSMART. Elle est professeure adjointe au Département de génie électrique et informatique de l'Université McGill et membre académique associé à Mila – Institut québécois d'intelligence artificielle. Elle est également affiliée au Centre sur les machines intelligentes de McGill (CIM), à l'Initiative de McGill en médecine computationnelle (MiCM) et à l'Institut de génie aérospatial de McGill (MIAE). Sa recherche porte sur le développement d'algorithmes novateurs pour divers domaines tels que l'analyse de données de séries temporelles, la vision par ordinateur, l'apprentissage par renforcement et l'apprentissage par représentation pour des tâches telles que le regroupement de données, la classification et la détection d'anomalies. Ses contributions au domaine de l'IA ont été reconnues par de nombreux prix, décernés notamment par le Conseil de recherches en sciences naturelles et en génie du Canada, AgeWell, Vanier-Banting, les Fonds de recherche du Québec, ainsi que l'Université McMaster, l'Université McGill, l'Université de Toronto, les Instituts de recherche en santé du Canada et Scale AI.

Étudiants actuels

Publications

Multistep networks for roll force prediction in hot strip rolling mill
Shuhong Shen
Denzel Guye
Xiaoping Ma
Stephen Yue
Deep Reinforcement Learning in Human Activity Recognition: A Survey
<div>Human activity recognition is a popular research field in computer vision that has already been widely studied. However, it is st… (voir plus)ill an active research field since it plays an important role in many current and emerging real world intelligent systems, like visual surveillance and human-computer interaction. Deep Reinforcement Learning (DRL) has recently been employed to address the activity recognition problem with various purposes, such as finding attention in video data or obtaining the best network structure. DRL-based human activity recognition has only been around for a short time, and it is a challenging, novel field[ of study. Therefore, to facilitate further research in this field, we have constructed a comprehensive survey on activity recognition methods that incorporate deep reinforcement learning. Towards the end of this survey, we summarize key challenges and open problems in this area that can be addressed by researchers in the future.</div>
Deep Successive Subspace Learning for Data Clustering
Deep clustering combines embedding and clustering together to obtain an optimal low dimensional embedding sub- space (aka latent subspace) f… (voir plus)or clustering, which can be more effective compared to conventional clustering approaches such as k-means. Typical deep clustering methods employ autoencoder (AE) and obtain their optimal latent space through minimizing data reconstruction loss which has no substantial connection with the clustering performance. In contrast, in this paper we propose a novel AE-based clustering scheme Deep Successive Subspace Learning (DSSL) which simultaneously minimizes weighted reconstruction and clustering losses of data points, where weights are defined based on similarity between latent representation of data points and cluster centers. DSSL obtains its optimal latent space through K (i.e. number of clusters) successive training runs where each run corresponds to an individual cluster. At each run, DSSL focuses on reconstruction and clustering of those data points that are more likely to belong to the corresponding cluster; hence, implicitly training those network parameters that have more influence on that cluster. Experimental results on benchmark datasets demonstrate that the proposed DSSL method can significantly outperform state-of-the-art clustering approaches.
Joint Selection using Deep Reinforcement Learning for Skeleton-based Activity Recognition
Bahareh Nikpour
<div>Skeleton based human activity recognition has attracted lots of attention due to its wide range of applications. Skeleton data in… (voir plus)cludes two or three dimensional coordinates of body joints. All of the body joints are not effective in recognizing different activities, so finding key joints within a video and across different activities has a significant role in improving the performance. In this paper we propose a novel framework that performs joint selection in skeleton video frames for the purpose of human activity recognition. To this end, we formulate the joint selection problem as a Markov Decision Process (MDP) where we employ deep reinforcement learning to find the most informative joints per frame. The proposed joint selection method is a general framework that can be employed to improve human activity classification methods. Experimental results on two benchmark activity recognition data sets using three different classifiers demonstrate effectiveness of the proposed joint selection method.</div>
Self-Supervised Acoustic Anomaly Detection Via Contrastive Learning.
We propose an acoustic anomaly detection algorithm based on the framework of contrastive learning. Contrastive learning is a recently propos… (voir plus)ed self-supervised approach that has shown promising results in image classification and speech recognition. However, its application in anomaly detection is underexplored. Earlier studies have demonstrated that it can achieve state-of-the-art performance in image anomaly detection, but its capability in anomalous sound detection is yet to be investigated. For the first time, we propose a contrastive learning-based framework that is suitable for acoustic anomaly detection. Since most existing contrastive learning approaches are targeted toward images, the effect of other data transformations on the performance of the algorithm is unknown. Our framework learns a representation from unlabeled data by applying audio-specific data augmentations. We show that in the resulting latent space, normal and abnormal points are distinguishable. Experiments conducted on the MIMII dataset confirm that our approach can outperform competing methods in detecting anomalies.
Deep Clustering with Self-supervision using Pairwise Data Similarities
Deep clustering incorporates embedding into clustering to find a lower-dimensional space appropriate for clustering. Most of the existing me… (voir plus)thods try to group similar data points through simultaneously minimizing clustering and reconstruction losses, employing an autoencoder (AE). However, they all ignore the relevant useful information available within pairwise data relationships. In this paper we propose a novel deep clustering framework with self-supervision using pairwise data similarities (DCSS). The proposed method consists of two successive phases. First, we propose a novel AE-based approach that aims to aggregate similar data points near a common group center in the latent space of an AE. The AE's latent space is obtained by minimizing weighted reconstruction and centering losses of data points, where weights are defined based on similarity of data points and group centers. In the second phase, we map the AE's latent space, using a fully connected network MNet, onto a K-dimensional space used to derive the final data cluster assignments, where K is the number of clusters. MNet is trained to strengthen (weaken) similarity of similar (dissimilar) samples. Experimental results on multiple benchmark datasets demonstrate the effectiveness of DCSS for data clustering and as a general framework for boosting up state-of-the-art clustering methods.