Christian Gagné

Mr. Christian Gagné


Research Focus & Metrics

Academic Career Length

18Years (2009-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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21 February 2018 in IEEE Transactions on Smart Grid
Verified
Journal Article
Closed access
KLKarol Lina Lopez
Karol Lina Lopez
CGChristian Gagné
Christian Gagné
MGMarc-Andre Gardner
Marc-Andre Gardner
The use of Electric Vehicles (EVs) load management is relevant to support electricity demand softening, making the grid more economic, efficient, and reliable. However, the absence of flexible strategies reflecting the self-interests of EV users may reduce their participation in this kind of initiative. In this work, we are proposing an intelligent charging strategy using Machine Learning (ML) tools, to determine when to charge the EV during connection sessions. This is achieved by making real-time charging decisions based on various auxiliary data, including driving, environment, pricing, and demand time series, in order to minimize the overall vehicle energy cost. The first step of the approach is to calculate the optimal solution of historical connection sessions using dynamic programming. Then, from these optimal decisions and other historical data, we train ML models to learn how to make the right decisions in real time, without knowledge of future energy prices and car usage. We demonstrated that a properly trained deep neural network is able to reduce charging costs significantly, often close to the optimal charging costs computed in a retrospective fashion.

27 July 2023 in Nature Machine Intelligence
Verified
Journal Article
Open access
PDF file
CBCatherine Bouchard
Catherine Bouchard
TWTheresa Wiesner
Theresa Wiesner
ADAndréanne Deschênes
Andréanne Deschênes
ABAnthony Bilodeau
Anthony Bilodeau
BTBenoît Turcotte
Benoît Turcotte
FLFlavie Lavoie-Cardinal
Flavie Lavoie-Cardinal
Super-resolution fluorescence microscopy methods enable the characterization of nanostructures in living and fixed biological tissues. However, they require the adjustment of multiple imaging parameters while attempting to satisfy conflicting objectives, such as maximizing spatial and temporal resolution while minimizing light exposure. To overcome the limitations imposed by these trade-offs, post-acquisition algorithmic approaches have been proposed for resolution enhancement and image-quality improvement. Here we introduce the task-assisted generative adversarial network (TA-GAN), which incorporates an auxiliary task (for example, segmentation, localization) closely related to the observed biological nanostructure characterization. We evaluate how the TA-GAN improves generative accuracy over unassisted methods, using images acquired with different modalities such as confocal, bright-field, stimulated emission depletion and structured illumination microscopy. The TA-GAN is incorporated directly into the acquisition pipeline of the microscope to predict the nanometric content of the field of view without requiring the acquisition of a super-resolved image. This information is used to automatically select the imaging modality and regions of interest, optimizing the acquisition sequence by reducing light exposure. Data-driven microscopy methods like the TA-GAN will enable the observation of dynamic molecular processes with spatial and temporal resolutions that surpass the limits currently imposed by the trade-offs constraining super-resolution microscopy.

21 August 2014 in Sensors
Verified
Journal Article
Open access
PDF file
VAVahab Akbarzadeh
Vahab Akbarzadeh
JLJulien-Charles Lévesque
Julien-Charles Lévesque
CGChristian Gagné
Christian Gagné
MPMarc Parizeau
Marc Parizeau
We are proposing an adaptation of the gradient descent method to optimize the position and orientation of sensors for the sensor placement problem. The novelty of the proposed method lies in the combination of gradient descent optimization with a realistic model, which considers both the topography of the environment and a set of sensors with directional probabilistic sensing. The performance of this approach is compared with two other black box optimization methods over area coverage and processing time. Results show that our proposed method produces competitive results on smaller maps and superior results on larger maps, while requiring much less computation than the other optimization methods to which it has been compared.

24 September 2022 in Knowledge-Based Systems
Verified
Journal Article
Closed access
CSChangjian Shui
Changjian Shui
QCQi Chen
Qi Chen
JWJun Wen
Jun Wen
FZFan Zhou
Fan Zhou
CGChristian Gagné
Christian Gagné
BWBoyu Wang
Boyu Wang

1 May 2018 in Artificial Intelligence in Medicine
Verified
Journal Article
Closed access
ANAhmed Najjar
Ahmed Najjar
DRDaniel Reinharz
Daniel Reinharz
CGCatherine Girouard
Catherine Girouard
CGChristian Gagné
Christian Gagné

1 January 2022 in Machine Learning
Verified
Journal Article
Open access
PDF file
CSChangjian Shui
Changjian Shui
BWBoyu Wang
Boyu Wang
CGChristian Gagné
Christian Gagné
A crucial aspect of reliable machine learning is to design a deployable system for generalizing new related but unobserved environments. Domain generalization aims to alleviate such a prediction gap between the observed and unseen environments. Previous approaches commonly incorporated learning the invariant representation for achieving good empirical performance. In this paper, we reveal that merely learning the invariant representation is vulnerable to the related unseen environment. To this end, we derive a novel theoretical analysis to control the unseen test environment error in the representation learning, which highlights the importance of controlling the smoothness of representation. In practice, our analysis further inspires an efficient regularization method to improve the robustness in domain generalization. The proposed regularization is orthogonal to and can be straightforwardly adopted in existing domain generalization algorithms that ensure invariant representation learning. Empirical results show that our algorithm outperforms the base versions in various datasets and invariance criteria.