79,831 results on '"Gagnon A"'
Search Results
2. Predicting future salinity variability in the Ca Mau Peninsula due to Climate Change
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Anh Duong Tran, Gagnon Alexandre S., Tanim Ahad Hasan, Wright David, and Thanh Phong Nguyen
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climate change ,sea level rise ,salinity intrusion ,ca mau peninsula ,mike-11 ,Environmental sciences ,GE1-350 - Abstract
The Ca Mau Peninsula (CMP) in Vietnam’s Lower Mekong Delta faces pressing challenges, including sea-level rise (SLR), land subsidence, flooding, and saltwater intrusion. Recent years have witnessed an earlier and more severe dry season, leading to heightened saltwater intrusion. As many CMP provinces rely on the Mekong River for their water supply, they are highly susceptible to prolonged drought and salinization. This study employs the MIKE 11 hydraulic model to project saltwater intrusion scenarios in the CMP up to 2050, based on Vietnam’s 2016 Ministry of Natural Resources and Environment (MONRE) SLR projections, considering water regulation from the Cai Lon-Cai Be sluice system. The modelled discharge, water level and salinity were calibrated and validated successfully based on di_erent statistical measures. The projections indicate that saltwater intrusion during the dry season could start 1 to 1.5 months earlier by 2050, with salinity levels exceeding 30 g/l in February. The findings underscore the importance of developing adaptation strategies to address the challenges of climate change and saltwater intrusion, notably in the region’s significant agricultural sector.
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- 2024
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3. ExcEL Leadership Academy Micro-Credential Pathway Adoption in Rhode Island. A Case Study
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Aurora Institute, Jennifer Cohen Kabaker, and Laurie Gagnon
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Despite calls to modernize education preparation, the way we train, support, and grow educators has remained largely unchanged for decades. But some educator training and professional development organizations are taking a different approach by offering educators flexible and job-embedded learning opportunities that recognize and validate learning through demonstrations of competence. Educators earn "micro-credentials" in the form of digital badges, which capture both the skill the educator demonstrated and the evidence they used to prove their mastery of that skill. This case study offers a look at one micro-credential program, developed by UCLA's ExcEL Leadership Academy that has been approved for ESOL teacher certification in Rhode Island. The program offers a progression of 12 micro-credentials focused on the skills and competencies educators need to serve multilingual learners (MLLs) effectively. Additionally, the case study offers recommendations for other states that hope to offer their educators high-quality competency-based pathways to certification and/or professional growth.
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- 2024
4. Mapping reionization bubbles in the JWST era I: empirical edge detection with Lyman alpha emission from galaxies
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Lu, Ting-Yi, Mason, Charlotte A., Mesinger, Andrei, Prelogović, David, Nikolić, Ivan, Hutter, Anne, Gagnon-Hartman, Samuel, Tang, Mengtao, Qin, Yuxiang, and Kakiichi, Koki
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Astrophysics - Astrophysics of Galaxies ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
Ionized bubble sizes during reionization trace physical properties of the first galaxies. JWST's ability to spectroscopically confirm and measure Lyman-alpha (Ly$\alpha$) emission in sub-L* galaxies opens the door to mapping ionized bubbles in 3D. However, existing Lya-based bubble measurement strategies rely on constraints from single galaxies, which are limited by the large variability in intrinsic Ly$\alpha$ emission. As a first step, we present two bubble size estimation methods using Lya spectroscopy of ensembles of galaxies, enabling us to map ionized structures and marginalize over Ly$\alpha$ emission variability. We test our methods using Gpc-scale reionization simulations of the intergalactic medium (IGM). To map bubbles in the plane of the sky, we develop an edge detection method based on the asymmetry of Ly$\alpha$ transmission as a function of spatial position. To map bubbles along the line-of-sight, we develop an algorithm using the tight relation between Ly$\alpha$ transmission and the line-of-sight distance from galaxies to the nearest neutral IGM patch. Both methods can robustly recover bubbles with radius $\gtrsim$10 comoving Mpc, sufficient for mapping bubbles even in the early phases of reionization, when the IGM is $\sim70-90\%$ neutral. These methods require $\gtrsim$0.002-0.004 galaxies/cMpc$^3$, a $5\sigma$ Ly$\alpha$ equivalent width upper limit of $\lesssim$30\r{A} for the faintest targets, and redshift precision $\Delta z \lesssim 0.015$, feasible with JWST spectroscopy. Shallower observations will provide robust lower limits on bubble sizes. Additional constraints on IGM transmission from Ly$\alpha$ escape fractions and line profiles will further refine these methods, paving the way to our first direct understanding of ionized bubble growth., Comment: 15 pages (+ 3 pages in Appendix), 17 figures, submitted to A&A
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- 2024
5. WiP: Towards a Secure SECP256K1 for Crypto Wallets: Hardware Architecture and Implementation
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Lemayian, Joel Poncha, Gagnon, Ghyslain, Zhang, Kaiwen, and Giard, Pascal
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Computer Science - Cryptography and Security ,Electrical Engineering and Systems Science - Signal Processing - Abstract
The SECP256K1 elliptic curve algorithm is fundamental in cryptocurrency wallets for generating secure public keys from private keys, thereby ensuring the protection and ownership of blockchain-based digital assets. However, the literature highlights several successful side-channel attacks on hardware wallets that exploit SECP256K1 to extract private keys. This work proposes a novel hardware architecture for SECP256K1, optimized for side-channel attack resistance and efficient resource utilization. The architecture incorporates complete addition formulas, temporary registers, and parallel processing techniques, making elliptic curve point addition and doubling operations indistinguishable. Implementation results demonstrate an average reduction of 45% in LUT usage compared to similar works, emphasizing the design's resource efficiency., Comment: Presented at HASP 2024 @ MICRO 2024 https://haspworkshop.org/2024/program.html
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- 2024
6. In-context learning and Occam's razor
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Elmoznino, Eric, Marty, Tom, Kasetty, Tejas, Gagnon, Leo, Mittal, Sarthak, Fathi, Mahan, Sridhar, Dhanya, and Lajoie, Guillaume
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Computer Science - Machine Learning ,Computer Science - Artificial Intelligence - Abstract
The goal of machine learning is generalization. While the No Free Lunch Theorem states that we cannot obtain theoretical guarantees for generalization without further assumptions, in practice we observe that simple models which explain the training data generalize best: a principle called Occam's razor. Despite the need for simple models, most current approaches in machine learning only minimize the training error, and at best indirectly promote simplicity through regularization or architecture design. Here, we draw a connection between Occam's razor and in-context learning: an emergent ability of certain sequence models like Transformers to learn at inference time from past observations in a sequence. In particular, we show that the next-token prediction loss used to train in-context learners is directly equivalent to a data compression technique called prequential coding, and that minimizing this loss amounts to jointly minimizing both the training error and the complexity of the model that was implicitly learned from context. Our theory and the empirical experiments we use to support it not only provide a normative account of in-context learning, but also elucidate the shortcomings of current in-context learning methods, suggesting ways in which they can be improved. We make our code available at https://github.com/3rdCore/PrequentialCode.
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- 2024
7. Quebec Automobile Insurance Question-Answering With Retrieval-Augmented Generation
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Beauchemin, David, Gagnon, Zachary, and Khoury, Ricahrd
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Computer Science - Computation and Language - Abstract
Large Language Models (LLMs) perform outstandingly in various downstream tasks, and the use of the Retrieval-Augmented Generation (RAG) architecture has been shown to improve performance for legal question answering (Nuruzzaman and Hussain, 2020; Louis et al., 2024). However, there are limited applications in insurance questions-answering, a specific type of legal document. This paper introduces two corpora: the Quebec Automobile Insurance Expertise Reference Corpus and a set of 82 Expert Answers to Layperson Automobile Insurance Questions. Our study leverages both corpora to automatically and manually assess a GPT4-o, a state-of-the-art LLM, to answer Quebec automobile insurance questions. Our results demonstrate that, on average, using our expertise reference corpus generates better responses on both automatic and manual evaluation metrics. However, they also highlight that LLM QA is unreliable enough for mass utilization in critical areas. Indeed, our results show that between 5% to 13% of answered questions include a false statement that could lead to customer misunderstanding., Comment: Accepted to NLLP 2024 EMNLP workshop
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- 2024
8. Multi-Objective Risk Assessment Framework for Exploration Planning Using Terrain and Traversability Analysis
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Souleiman, Riana Gagnon, Varadharajan, Vivek Shankar, and Beltrame, Giovanni
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Computer Science - Robotics - Abstract
Exploration of unknown, unstructured environments, such as in search and rescue, cave exploration, and planetary missions,presents significant challenges due to their unpredictable nature. This unpredictability can lead to inefficient path planning and potential mission failures. We propose a multi-objective risk assessment method for exploration planning in such unconstrained environments. Our approach dynamically adjusts the weight of various risk factors to prevent the robot from undertaking lethal actions too early in the mission. By gradually increasing the allowable risk as the mission progresses, our method enables more efficient exploration. We evaluate risk based on environmental terrain properties, including elevation, slope, roughness, and traversability, and account for factors like battery life, mission duration, and travel distance. Our method is validated through experiments in various subterranean simulated cave environments. The results demonstrate that our approach ensures consistent exploration without incurring lethal actions, while introducing minimal computational overhead to the planning process., Comment: 7 pages, 8 figures, submitted to ICRA 2025
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- 2024
9. FastLexRank: Efficient Lexical Ranking for Structuring Social Media Posts
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Li, Mao, Conrad, Frederick, and Gagnon-Bartsch, Johann
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Computer Science - Computation and Language ,Statistics - Computation - Abstract
We present FastLexRank\footnote{https://github.com/LiMaoUM/FastLexRank}, an efficient and scalable implementation of the LexRank algorithm for text ranking. Designed to address the computational and memory complexities of the original LexRank method, FastLexRank significantly reduces time and memory requirements from $\mathcal{O}(n^2)$ to $\mathcal{O}(n)$ without compromising the quality or accuracy of the results. By employing an optimized approach to calculating the stationary distribution of sentence graphs, FastLexRank maintains an identical results with the original LexRank scores while enhancing computational efficiency. This paper details the algorithmic improvements that enable the processing of large datasets, such as social media corpora, in real-time. Empirical results demonstrate its effectiveness, and we propose its use in identifying central tweets, which can be further analyzed using advanced NLP techniques. FastLexRank offers a scalable solution for text centrality calculation, addressing the growing need for efficient processing of digital content.
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- 2024
10. A Holistic Understanding of Inclusion in STEM: Systemic Challenges and Support for Women and LGBT+ Academics and PhD Students
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Marco Reggiani, Jessica Dawn Gagnon, and Rebecca Jane Lunn
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Barriers to equity, diversity, and inclusion remain in Science, Technology, Engineering, and Mathematics (STEM) for historically underrepresented and marginalized individuals. The purpose of this study was to explore the experiences of women and LGBT+ academics and PhD students in the United Kingdom. Specifically, this article examines systemic challenges and support that 82 participants who identified as women and/or LGBT+ academics and PhD students have experienced in their STEM environments and throughout their careers. In this qualitative study, we employed intersectionality theory to frame a thematic analysis of interviews and focus groups. Our findings indicate that the experiences of participants are characterized more by inequities than by support from colleagues, peers, and higher education institutions. Inequities are widespread and intersectional, and have a cumulative impact whenever individuals endure multiple and potentially escalating challenges--which include hard-to-spot disadvantages, stereotypes, prejudice, as well as harassment, bullying, and discrimination. Participants' accounts illustrate the benefits of different support mechanisms but also the limitations of initiatives to support marginalized individuals and groups in STEM that are not systematically embedded across institutions. Based on our findings, we present two conceptual models to better understand systemic challenges and their consequences for women and LGBT+ academics and PhD students in STEM, as well as to inform more holistic support mechanisms to create more inclusive STEM environments. Implications from the study highlight institutional accountability as key to improving climates and transformative change.
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- 2024
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11. HPV Vaccination Rates of 7th Grade Students after a Strong Recommending Statement from the School Nurse
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Laura Santangelo White, Emily Maulucci, Melanie Kornides, Subhash Aryal, Catherine Alix, Diane Sneider, Jessica Gagnon, Elizabeth C. Winfield, and Holly B. Fontenot
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The Human Papillomavirus (HPV) vaccine can prevent 90% of cancers caused by HPV. Health care provider recommendations affect vaccine uptake, yet there are a lack of studies examining the impact of the school nurse (SN) in vaccine recommendations. The purpose of this study was to evaluate the impact of adding a SN HPV recommendation to the standard vaccination letter sent to parents/guardians. The rate of vaccination between the intervention and control schools was not statistically significant (Estimate (Std. Error) = -0.3066 (0.2151), p = 0.154). After controlling for age, sex, race, insurance type, and medical practice type, there was no significant difference in the likelihood to receive the HPV vaccine (OR = 1.53, 95% CI: 0.563-4.19 in 2018; OR = 1.34, 95% CI: 0.124-14.54 in 2019. Further work is needed to clarify how school nurses can better promote HPV vaccine, and which adolescent demographic groups (e.g., race, insurance type, provider type) face barriers to HPV vaccine uptake.
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- 2024
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12. On a fundamental difference between Bayesian and frequentist approaches to robustness
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Gagnon, Philippe and Desgagné, Alain
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Statistics - Methodology - Abstract
Heavy-tailed models are often used as a way to gain robustness against outliers in Bayesian analyses. On the other side, in frequentist analyses, M-estimators are often employed. In this paper, the two approaches are reconciled by considering M-estimators as maximum likelihood estimators of heavy-tailed models. We realize that, even from this perspective, there is a fundamental difference in that frequentists do not require these heavy-tailed models to be proper. It is shown what the difference between improper and proper heavy-tailed models can be in terms of estimation results through two real-data analyses based on linear regression. The findings of this paper make us ponder on the use of improper heavy-tailed data models in Bayesian analyses, an approach which is seen to fit within the generalized Bayesian framework of Bissiri et al. (2016) when combined with proper prior distributions yielding proper (generalized) posterior distributions.
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- 2024
13. A General Framework for Design-Based Treatment Effect Estimation in Paired Cluster-Randomized Experiments
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Mann, Charlotte Z., Sales, Adam C., and Gagnon-Bartsch, Johann A.
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Statistics - Methodology ,Statistics - Applications - Abstract
Paired cluster-randomized experiments (pCRTs) are common across many disciplines because there is often natural clustering of individuals, and paired randomization can help balance baseline covariates to improve experimental precision. Although pCRTs are common, there is surprisingly no obvious way to analyze this randomization design if an individual-level (rather than cluster-level) treatment effect is of interest. Variance estimation is also complicated due to the dependency created through pairing clusters. Therefore, we aim to provide an intuitive and practical comparison between different estimation strategies in pCRTs in order to inform practitioners' choice of strategy. To this end, we present a general framework for design-based estimation in pCRTs for average individual effects. This framework offers a novel and intuitive view on the bias-variance trade-off between estimators and emphasizes the benefits of covariate adjustment for estimation with pCRTs. In addition to providing a general framework for estimation in pCRTs, the point and variance estimators we present support fixed-sample unbiased estimation with similar precision to a common regression model and consistently conservative variance estimation. Through simulation studies, we compare the performance of the point and variance estimators reviewed. Finally, we compare the performance of estimators with simulations using real data from an educational efficacy trial. Our analysis and simulation studies inform the choice of point and variance estimators for analyzing pCRTs in practice.
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- 2024
14. Insect Identification in the Wild: The AMI Dataset
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Jain, Aditya, Cunha, Fagner, Bunsen, Michael James, Cañas, Juan Sebastián, Pasi, Léonard, Pinoy, Nathan, Helsing, Flemming, Russo, JoAnne, Botham, Marc, Sabourin, Michael, Fréchette, Jonathan, Anctil, Alexandre, Lopez, Yacksecari, Navarro, Eduardo, Pimentel, Filonila Perez, Zamora, Ana Cecilia, Silva, José Alejandro Ramirez, Gagnon, Jonathan, August, Tom, Bjerge, Kim, Segura, Alba Gomez, Bélisle, Marc, Basset, Yves, McFarland, Kent P., Roy, David, Høye, Toke Thomas, Larrivée, Maxim, and Rolnick, David
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Computer Science - Computer Vision and Pattern Recognition ,Computer Science - Artificial Intelligence ,Computer Science - Machine Learning - Abstract
Insects represent half of all global biodiversity, yet many of the world's insects are disappearing, with severe implications for ecosystems and agriculture. Despite this crisis, data on insect diversity and abundance remain woefully inadequate, due to the scarcity of human experts and the lack of scalable tools for monitoring. Ecologists have started to adopt camera traps to record and study insects, and have proposed computer vision algorithms as an answer for scalable data processing. However, insect monitoring in the wild poses unique challenges that have not yet been addressed within computer vision, including the combination of long-tailed data, extremely similar classes, and significant distribution shifts. We provide the first large-scale machine learning benchmarks for fine-grained insect recognition, designed to match real-world tasks faced by ecologists. Our contributions include a curated dataset of images from citizen science platforms and museums, and an expert-annotated dataset drawn from automated camera traps across multiple continents, designed to test out-of-distribution generalization under field conditions. We train and evaluate a variety of baseline algorithms and introduce a combination of data augmentation techniques that enhance generalization across geographies and hardware setups., Comment: Published at ECCV 2024. The dataset is publicly available at https://github.com/RolnickLab/ami-dataset
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- 2024
15. Mathematics, 3D Printing, and Computational Thinking through Work-Based Learning (MPACT): An Education Innovation and Research (EIR) Grant Evaluation. Technical Report
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SRI Education, Douglas Gagnon, Ela Joshi, Nicole Arshan, Eliese Rulifson, Elise Levin-Güracar, and Tejaswini Tiruke
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The Mathematics, 3D Printing, and Computational Thinking Through Work-Based Learning (MPACT) program combines teacher professional development, specialized curriculum and materials and STEM industry mentors to provide grade 4-7 students with project-based experiences implemented across three learning modules. This technical report presents findings from SRI International's evaluation of MPACT implementationin the 2021-22 school year by MPACT Fellows--i.e., teachers who participated in the MPACT program--in four U.S. states. MPACT Fellows implemented the program in a year marked by ongoing difficulties due to the COVID-19 pandemic. Although MPACT professional development was delivered with fidelity, only 65% of MPACT Fellows implemented the full program (all three modules) with all of their classes. MPACT Fellows also provided fewer opportunities for students to meet with or learn about STEM industry mentors than intended. Despite this partial implementation, MPACT Fellows' perceptions of and efficacy in programmatic concepts increased meaningfully after participating in MPACT. Further, grade 4 and 5 MPACT students grew nearly a full standard deviation on a measure of geometry, computational thinking, and spatial reasoning over one school year. However, significant differences were not observed in students' socioemotional outcomes--specifically, behavioral engagement in math, behavioral disaffection in math, math self-efficacy, and math self-concept--between MPACT students and students in the comparison group. The considerable growth of MPACT students on the assessment and the documented program impacts on teachers' perceptions provide limited but suggestive evidence that the program could demonstrate improved student outcomes in ideal conditions, if examined over a longer time frame or using different impact measures.
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- 2023
16. Evaluating the Clinical Utility of the MAYSI-2 among African American Male Juvenile Offenders
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Brittany LaBelle, Joseph Calvin Gagnon, Diana Joyce-Beaulieu, Jodi Lane, Nicholas Gage, John Kranzler, David E. Houchins, Holly B. Lane, Erica D. McCray, Richard G. Lambert, and Shelbretta Ball
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This study examined the clinical utility of the Massachusetts Youth Screening Instrument--Second Version (MAYSI-2) among African American (AA) incarcerated youth and used White incarcerated youth as a comparison group. Data were analyzed for 314 incarcerated youth (193 AA offenders and 121 White offenders) of ages 13-17 years who were adjudicated delinquent from a southeastern United States medium security residential facility. Seven logistic regression and receiver operating characteristic curve (ROC) models were built to determine whether the MAYSI-2 subscales accurately identify committed AA male incarcerated youth who have a mental illness diagnosis on file. Analyses also examined how well the MAYSI-2 subscales identify specific mental illnesses among AA-committed male incarcerated youth. Results demonstrated that no MAYSI-2 subscales accurately identified and categorized AA-committed male incarcerated youth who have mental disorders, and only two subscales (Alcohol/Drug Use, Depressed/Anxious) identified and categorized White committed male incarcerated youth who have a mental disorder. Additional results and implications for research and practice are provided.
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- 2024
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17. Ocean weather, biological rates, and unexplained global ecological patterns.
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Li Shing Hiung, Darren, Schuster, Jasmin, Duncan, Murray, Payne, Nicholas, Helmuth, Brian, Chu, Jackson, Baum, Julia, Brambilla, Viviana, Bruno, John, Davies, Sarah, Dornelas, Maria, Gagnon, Patrick, Guy-Haim, Tamar, Jackson, Jennifer, Leichter, James, Madin, Joshua, Monteith, Zachary, Queirós, Ana, Schneider, Eric, Starko, Samuel, Talwar, Brendan, Wyatt, Alex, Aichelman, Hannah, Bensoussan, Nathaniel, Caruso, Carlo, Castillo, Karl, Choi, Francis, Dong, Yun-Wei, Garrabou, Joaquim, Guillemain, Dorian, Higgs, Nicholas, Jiang, Yuwu, Kersting, Diego, Kushner, David, Longo, Guilherme, Neufeld, Christopher, Peirache, Marion, Smyth, Tim, Sprague, Joshua, Urvoy, Gaëlle, Zuberer, Frederic, and Bates, Amanda
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biological rate ,climate variability hypothesis ,high frequency ,in situ ,ocean temperature - Abstract
As on land, oceans exhibit high temporal and spatial temperature variation. This ocean weather contributes to the physiological and ecological processes that ultimately determine the patterns of species distribution and abundance, yet is often unrecognized, especially in tropical oceans. Here, we tested the paradigm of temperature stability in shallow waters (
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- 2024
18. Outcomes of surgically treated sialoceles in 21 cats: A multi‐institutional retrospective study (2010–2021)
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Marti, Laura G, Brisson, Brigitte A, Del Carpio, Laura‐Isabela, Goldschmidt, Stephanie, Buote, Nicole, Gagnon, Dominique, Shmon, Cindy, Sterman, Allyson A, Scharf, Valery F, MacPhail, Catriona M, Maki, Lynn, and Arzi, Boaz
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Veterinary Sciences ,Agricultural ,Veterinary and Food Sciences ,Clinical Research ,Dental/Oral and Craniofacial Disease ,Digestive Diseases ,Patient Safety ,Veterinary sciences - Abstract
To report the outcomes of cats that underwent surgical correction for sialoceles. Multi-institutional retrospective cohort study. Twenty-one client-owned cats. Medical records were examined of cats diagnosed with sialocele, which underwent surgical intervention over an 11-year period at one of 10 referral hospitals. The data collected included signalment, clinical signs, diagnostic imaging, histopathology, surgical procedures performed, and postoperative complications. The most common presenting complaints for cats with sialocele included dysphagia and ptyalism. Only two cats had a recent history of trauma, and one was diagnosed with a concurrent sialolith. Most displayed visible tissue swelling, with ranulae being most common. Surgical treatment consisted of sialoadenectomy and/or marsupialization. Intraoperative complications occurred in three cats, and postoperative complications in five cats. No recurrence or development of contralateral sialoceles were reported during the follow-up period (30-968 days). The majority of cats did not have a clear underlying cause for developing a sialocele. The sublingual and mandibular salivary glands were presumed to be the most commonly affected. Mandibular and sublingual sialoadenectomy and/or marsupialization provided resolution of clinical signs to the 21 cats that underwent these procedures. Sialocele, although rare, should remain a differential diagnosis when managing cats with relevant clinical signs. Surgical intervention appears to offer resolution of signs with apparently low overall risk of complication or short-term recurrence. In cats it is necessary to evaluate whether sialoadenectomy is necessary, or whether marsupialization alone should be attempted as a less invasive first-line surgical intervention.
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- 2024
19. Generation planning and operation under power stability constraints: A Hydro-Quebec use case
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Besner, Alexandre, Massé, Alexandre Blondin, Bani, Abderrahman, Morabit, Mouad, Berthaut, François, Charest, Luc, Ialongo, David, Mbeutcha, Yves, Couture-Gagnon, Simon, and Fournier, Julien
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Electrical Engineering and Systems Science - Systems and Control - Abstract
Hydro-Quebec (HQ) is a vertically integrated utility that produces, transmits, and distributes most of the electricity in the province of Quebec. The power grid it operates has a particular architecture created by large hydroelectric dams located far north and the extensive 735kV transmission grid that allows the generated power to reach the majority of the load located thousands of kilometers away in the southern region of Quebec. The specificity of the grid has led HQ to develop monitoring tools responsible for generating so-called stability limits. Those stability limits take into account several nonlinear phenomena such as angular stability, frequency stability, or voltage stability. Since generation planning and operation tools rely mostly on mixed integer linear programming formulation, HQ had to adapt its tools to integrate stability limits into them. This paper presents the challenges it faced, especially considering its reserve monitoring tool and unit commitment tool., Comment: 12 pages, 7 figures, 7 tables, 1 algorithm
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- 2024
20. Does learning the right latent variables necessarily improve in-context learning?
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Mittal, Sarthak, Elmoznino, Eric, Gagnon, Leo, Bhardwaj, Sangnie, Sridhar, Dhanya, and Lajoie, Guillaume
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Computer Science - Machine Learning ,Computer Science - Artificial Intelligence - Abstract
Large autoregressive models like Transformers can solve tasks through in-context learning (ICL) without learning new weights, suggesting avenues for efficiently solving new tasks. For many tasks, e.g., linear regression, the data factorizes: examples are independent given a task latent that generates the data, e.g., linear coefficients. While an optimal predictor leverages this factorization by inferring task latents, it is unclear if Transformers implicitly do so or if they instead exploit heuristics and statistical shortcuts enabled by attention layers. Both scenarios have inspired active ongoing work. In this paper, we systematically investigate the effect of explicitly inferring task latents. We minimally modify the Transformer architecture with a bottleneck designed to prevent shortcuts in favor of more structured solutions, and then compare performance against standard Transformers across various ICL tasks. Contrary to intuition and some recent works, we find little discernible difference between the two; biasing towards task-relevant latent variables does not lead to better out-of-distribution performance, in general. Curiously, we find that while the bottleneck effectively learns to extract latent task variables from context, downstream processing struggles to utilize them for robust prediction. Our study highlights the intrinsic limitations of Transformers in achieving structured ICL solutions that generalize, and shows that while inferring the right latents aids interpretability, it is not sufficient to alleviate this problem.
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- 2024
21. On the modification and revocation of open source licences
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Gagnon, Paul, Benjamin, Misha, Gauthier, Justine, Regis, Catherine, Lee, Jenny, and Nordell-Markovits, Alexei
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Computer Science - Digital Libraries ,Computer Science - Computers and Society - Abstract
Historically, open source commitments have been deemed irrevocable once materials are released under open source licenses. In this paper, the authors argue for the creation of a subset of rights that allows open source contributors to force users to (i) update to the most recent version of a model, (ii) accept new use case restrictions, or even (iii) cease using the software entirely. While this would be a departure from the traditional open source approach, the legal, reputational and moral risks related to open-sourcing AI models could justify contributors having more control over downstream uses. Recent legislative changes have also opened the door to liability of open source contributors in certain cases. The authors believe that contributors would welcome the ability to ensure that downstream users are implementing updates that address issues like bias, guardrail workarounds or adversarial attacks on their contributions. Finally, this paper addresses how this license category would interplay with RAIL licenses, and how it should be operationalized and adopted by key stakeholders such as OSS platforms and scanning tools.
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- 2024
22. Brain Tumor Segmentation (BraTS) Challenge 2024: Meningioma Radiotherapy Planning Automated Segmentation
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LaBella, Dominic, Schumacher, Katherine, Mix, Michael, Leu, Kevin, McBurney-Lin, Shan, Nedelec, Pierre, Villanueva-Meyer, Javier, Shapey, Jonathan, Vercauteren, Tom, Chia, Kazumi, Al-Salihi, Omar, Leu, Justin, Halasz, Lia, Velichko, Yury, Wang, Chunhao, Kirkpatrick, John, Floyd, Scott, Reitman, Zachary J., Mullikin, Trey, Bagci, Ulas, Sachdev, Sean, Hattangadi-Gluth, Jona A., Seibert, Tyler, Farid, Nikdokht, Puett, Connor, Pease, Matthew W., Shiue, Kevin, Anwar, Syed Muhammad, Faghani, Shahriar, Haider, Muhammad Ammar, Warman, Pranav, Albrecht, Jake, Jakab, András, Moassefi, Mana, Chung, Verena, Aristizabal, Alejandro, Karargyris, Alexandros, Kassem, Hasan, Pati, Sarthak, Sheller, Micah, Huang, Christina, Coley, Aaron, Ghanta, Siddharth, Schneider, Alex, Sharp, Conrad, Saluja, Rachit, Kofler, Florian, Lohmann, Philipp, Vollmuth, Phillipp, Gagnon, Louis, Adewole, Maruf, Li, Hongwei Bran, Kazerooni, Anahita Fathi, Tahon, Nourel Hoda, Anazodo, Udunna, Moawad, Ahmed W., Menze, Bjoern, Linguraru, Marius George, Aboian, Mariam, Wiestler, Benedikt, Baid, Ujjwal, Conte, Gian-Marco, Rauschecker, Andreas M., Nada, Ayman, Abayazeed, Aly H., Huang, Raymond, de Verdier, Maria Correia, Rudie, Jeffrey D., Bakas, Spyridon, and Calabrese, Evan
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Computer Science - Computer Vision and Pattern Recognition ,Computer Science - Artificial Intelligence ,Computer Science - Human-Computer Interaction ,Computer Science - Machine Learning - Abstract
The 2024 Brain Tumor Segmentation Meningioma Radiotherapy (BraTS-MEN-RT) challenge aims to advance automated segmentation algorithms using the largest known multi-institutional dataset of radiotherapy planning brain MRIs with expert-annotated target labels for patients with intact or postoperative meningioma that underwent either conventional external beam radiotherapy or stereotactic radiosurgery. Each case includes a defaced 3D post-contrast T1-weighted radiotherapy planning MRI in its native acquisition space, accompanied by a single-label "target volume" representing the gross tumor volume (GTV) and any at-risk postoperative site. Target volume annotations adhere to established radiotherapy planning protocols, ensuring consistency across cases and institutions. For preoperative meningiomas, the target volume encompasses the entire GTV and associated nodular dural tail, while for postoperative cases, it includes at-risk resection cavity margins as determined by the treating institution. Case annotations were reviewed and approved by expert neuroradiologists and radiation oncologists. Participating teams will develop, containerize, and evaluate automated segmentation models using this comprehensive dataset. Model performance will be assessed using an adapted lesion-wise Dice Similarity Coefficient and the 95% Hausdorff distance. The top-performing teams will be recognized at the Medical Image Computing and Computer Assisted Intervention Conference in October 2024. BraTS-MEN-RT is expected to significantly advance automated radiotherapy planning by enabling precise tumor segmentation and facilitating tailored treatment, ultimately improving patient outcomes., Comment: 14 pages, 9 figures, 1 table
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- 2024
23. The 2024 Brain Tumor Segmentation (BraTS) Challenge: Glioma Segmentation on Post-treatment MRI
- Author
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de Verdier, Maria Correia, Saluja, Rachit, Gagnon, Louis, LaBella, Dominic, Baid, Ujjwall, Tahon, Nourel Hoda, Foltyn-Dumitru, Martha, Zhang, Jikai, Alafif, Maram, Baig, Saif, Chang, Ken, D'Anna, Gennaro, Deptula, Lisa, Gupta, Diviya, Haider, Muhammad Ammar, Hussain, Ali, Iv, Michael, Kontzialis, Marinos, Manning, Paul, Moodi, Farzan, Nunes, Teresa, Simon, Aaron, Sollmann, Nico, Vu, David, Adewole, Maruf, Albrecht, Jake, Anazodo, Udunna, Chai, Rongrong, Chung, Verena, Faghani, Shahriar, Farahani, Keyvan, Kazerooni, Anahita Fathi, Iglesias, Eugenio, Kofler, Florian, Li, Hongwei, Linguraru, Marius George, Menze, Bjoern, Moawad, Ahmed W., Velichko, Yury, Wiestler, Benedikt, Altes, Talissa, Basavasagar, Patil, Bendszus, Martin, Brugnara, Gianluca, Cho, Jaeyoung, Dhemesh, Yaseen, Fields, Brandon K. K., Garrett, Filip, Gass, Jaime, Hadjiiski, Lubomir, Hattangadi-Gluth, Jona, Hess, Christopher, Houk, Jessica L., Isufi, Edvin, Layfield, Lester J., Mastorakos, George, Mongan, John, Nedelec, Pierre, Nguyen, Uyen, Oliva, Sebastian, Pease, Matthew W., Rastogi, Aditya, Sinclair, Jason, Smith, Robert X., Sugrue, Leo P., Thacker, Jonathan, Vidic, Igor, Villanueva-Meyer, Javier, White, Nathan S., Aboian, Mariam, Conte, Gian Marco, Dale, Anders, Sabuncu, Mert R., Seibert, Tyler M., Weinberg, Brent, Abayazeed, Aly, Huang, Raymond, Turk, Sevcan, Rauschecker, Andreas M., Farid, Nikdokht, Vollmuth, Philipp, Nada, Ayman, Bakas, Spyridon, Calabrese, Evan, and Rudie, Jeffrey D.
- Subjects
Computer Science - Computer Vision and Pattern Recognition - Abstract
Gliomas are the most common malignant primary brain tumors in adults and one of the deadliest types of cancer. There are many challenges in treatment and monitoring due to the genetic diversity and high intrinsic heterogeneity in appearance, shape, histology, and treatment response. Treatments include surgery, radiation, and systemic therapies, with magnetic resonance imaging (MRI) playing a key role in treatment planning and post-treatment longitudinal assessment. The 2024 Brain Tumor Segmentation (BraTS) challenge on post-treatment glioma MRI will provide a community standard and benchmark for state-of-the-art automated segmentation models based on the largest expert-annotated post-treatment glioma MRI dataset. Challenge competitors will develop automated segmentation models to predict four distinct tumor sub-regions consisting of enhancing tissue (ET), surrounding non-enhancing T2/fluid-attenuated inversion recovery (FLAIR) hyperintensity (SNFH), non-enhancing tumor core (NETC), and resection cavity (RC). Models will be evaluated on separate validation and test datasets using standardized performance metrics utilized across the BraTS 2024 cluster of challenges, including lesion-wise Dice Similarity Coefficient and Hausdorff Distance. Models developed during this challenge will advance the field of automated MRI segmentation and contribute to their integration into clinical practice, ultimately enhancing patient care., Comment: 10 pages, 4 figures, 1 table
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- 2024
24. Theoretical guarantees for lifted samplers
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Gagnon, Philippe and Maire, Florian
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Statistics - Computation ,Mathematics - Statistics Theory - Abstract
Lifted samplers form a class of Markov chain Monte Carlo methods which has drawn a lot attention in recent years due to superior performance in challenging Bayesian applications. A canonical example of such sampler is the one that is derived from a random walk Metropolis algorithm for a totally-ordered state space such as the integers or the real numbers. The lifted sampler is derived by splitting into two the proposal distribution: one part in the increasing direction, and the other part in the decreasing direction. It keeps following a direction, until a rejection, upon which it flips the direction. In terms of asymptotic variances, it outperforms the random walk Metropolis algorithm, regardless of the target distribution, at no additional computational cost. Other studies show, however, that beyond this simple case, lifted samplers do not always outperform their Metropolis counterparts. In this paper, we leverage the celebrated work of Tierney (1998) to provide an analysis in a general framework encompassing a broad class of lifted samplers. Our finding is that, essentially, the asymptotic variances cannot increase by a factor of more than 2, regardless of the target distribution, the way the directions are induced, and the type of algorithm from which the lifted sampler is derived (be it a Metropolis--Hastings algorithm, a reversible jump algorithm, etc.). This result indicates that, while there is potentially a lot to gain from lifting a sampler, there is not much to lose.
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- 2024
25. Expanding Student Access to Work-Based Learning: Federal Policy Recommendations
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Aurora Institute, Patrick, Susan, Alderman, Khamiah, and Gagnon, Laurie
- Abstract
We know the importance of learning experiences that happen beyond the confines of a traditional classroom. But how might federal policy support such experiences to prepare young people for life after high school? That's where work-based learning comes in -- a strategy designed to help students connect what they learn in the classroom with what is expected in the workplace by integrating learning with real-world applications in partnership with industry professionals. While momentum is growing at the local and state levels to design and implement PK-12 through workforce pathways to support work-based learning, there is still much work to be done in creating truly supportive policy environments. This set of federal policy recommendations outlines how enabling policies could further incentivize and focus increased resources on pathways and work-based learning.
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- 2023
26. Going beyond the Traditional: Next Gen Credentials and Flexible Learning Pathways
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Aurora Institute, Gagnon, Laurie, Patrick, Susan, and Weaver, Alyssa
- Abstract
The new world of work demands not only academic knowledge and skills but also transferable skills such as communications, creativity, and collaboration--skills that are rarely captured formally. Meeting that demand will require a new approach to the high school diploma. The opportunity is ripe to redesign credentials to enable competency-based pathways and learning. The transcript for the next generation ("next gen") of learning and work will better represent what individuals have actually learned, what they know, and what they can do. It's time to explore how all learners (adults and youth) could record and communicate their learning from a variety of powerful learning experiences using the next generation of credentials. The goal of this report is to deepen state policy makers' understanding of the changes needed to facilitate meaningful next gen credentials and advance state policy to support those changes. This includes building support to modernize education, opening pathways for learning and reskilling, and providing value for lifelong learning to both individuals and employers. Students, families, employers, and organizations focused on education and employment, as well as nations around the globe, are exploring how to ensure students receive a world-class education that builds knowledge and skills needed for the future. New models of credentialing knowledge, skills, and qualifications are emerging to help achieve this goal. [Funding was provided by the Stand Together Trust.]
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- 2023
27. Most azole resistance mutations in the Candida albicans drug target confer cross-resistance without intrinsic fitness cost
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Bédard, Camille, Gagnon-Arsenault, Isabelle, Boisvert, Jonathan, Plante, Samuel, Dubé, Alexandre K., Pageau, Alicia, Fijarczyk, Anna, Sharma, Jehoshua, Maroc, Laetitia, Shapiro, Rebecca S., and Landry, Christian R.
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- 2024
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28. Beyond the Guidelines: Perspectives on Management of Pediatric Patients with Hypertriglyceridemia
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Gagnon, Charles A. and Ashraf, Ambika P.
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- 2024
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29. CRISPR–Cas9 screens reveal regulators of ageing in neural stem cells
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Ruetz, Tyson J., Pogson, Angela N., Kashiwagi, Chloe M., Gagnon, Stephanie D., Morton, Bhek, Sun, Eric D., Na, Jeeyoon, Yeo, Robin W., Leeman, Dena S., Morgens, David W., Tsui, C. Kimberly, Li, Amy, Bassik, Michael C., and Brunet, Anne
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- 2024
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30. When Misleading Information Hits: How Canadian Companies React?
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Agbodoh-Falschau, Raymond K., Lamzihri, Othmane, and Gagnon, Stephane
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- 2024
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31. Development of AI-assisted microscopy frameworks through realistic simulation with pySTED
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Bilodeau, Anthony, Michaud-Gagnon, Albert, Chabbert, Julia, Turcotte, Benoit, Heine, Jörn, Durand, Audrey, and Lavoie-Cardinal, Flavie
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- 2024
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32. Proceedings of the Canadian Medication Appropriateness and Deprescribing Network’s 2023 National Meeting
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Pierson, Tiphaine, Arcand, Verna, Farrell, Barbara, Gagnon, Camille L., Leung, Larry, McCarthy, Lisa M., Murphy, Andrea L., Persaud, Nav, Raman-Wilms, Lalitha, Silvius, James L., Steinman, Michael A., Tannenbaum, Cara, Thompson, Wade, Trimble, Johanna, Sadowski, Cheryl A., and McDonald, Emily G.
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- 2024
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33. Effects of Foliation Type and Orientation on Tensile Strength of Low Porosity Rocks
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Packulak, Timothy R. M., Gagnon, Émelie, Day, Jennifer J., and Diederichs, Mark S.
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- 2024
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34. Improvement Of Audiovisual Quality Estimation Using A Nonlinear Autoregressive Exogenous Neural Network And Bitstream Parameters
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Kossi, Koffi, Coulombe, Stephane, Desrosiers, Christian, and Gagnon, Ghyslain
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Electrical Engineering and Systems Science - Image and Video Processing ,Computer Science - Sound ,Electrical Engineering and Systems Science - Audio and Speech Processing - Abstract
With the increasing demand for audiovisual services, telecom service providers and application developers are compelled to ensure that their services provide the best possible user experience. Particularly, services such as videoconferencing are very sensitive to network conditions. Therefore, their performance should be monitored in real time in order to adjust parameters to any network perturbation. In this paper, we developed a parametric model for estimating the perceived audiovisual quality in videoconference services. Our model is developed with the nonlinear autoregressive exogenous (NARX) recurrent neural network and estimates the perceived quality in terms of mean opinion score (MOS). We validate our model using the publicly available INRS bitstream audiovisual quality dataset. This dataset contains bitstream parameters such as loss per frame, bit rate and video duration. We compare the proposed model against state-of-the-art methods based on machine learning and show our model to outperform these methods in terms of mean square error (MSE=0.150) and Pearson correlation coefficient (R=0.931)
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- 2024
35. Anisotropic induced polarization modeling with neural networks and effective medium theory
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Bérubé, Charles L. and Gagnon, Jean-Luc
- Subjects
Physics - Geophysics - Abstract
Accurately interpreting induced polarization (IP) data that reflects the inherent anisotropy of the Earth's crust requires anisotropic IP models. The Generalized Effective Medium Theory of Induced Polarization (GEMTIP) model effectively simulates the IP signatures of rocks containing polarizable minerals. A pivotal element of the GEMTIP model is calculating the depolarization tensor elements, an intensive task for anisotropic rocks because one must numerically solve six parametric integrals for each mineral inclusion. This study aims to streamline anisotropic IP simulations by extending the GEMTIP framework and introducing a machine learning approach to estimate the depolarization tensors. The theoretical contributions of this research are two-fold: (1) we augment the GEMTIP model to encompass anisotropic background conductivity and triaxial ellipsoidal inclusions, and (2) we reformulate the depolarization integrals to normalize their input and output variables, facilitating their estimation by neural networks. Validation against analytical solutions for spherical and spheroidal inclusions corroborates the accuracy of the neural network. Analyzing the neural network model, we find that the relationship between chargeability and polarizable inclusion content is increasingly uncertain for increasingly anisotropic rocks. A similar observation applies to the relationship between critical frequency and host rock conductivity. Moreover, the depolarization tensors are, on average, 56 % sensitive to inclusion anisotropy and 44 % sensitive to host rock conductivity anisotropy. Remarkably, our neural network drastically accelerates GEMTIP simulations--up to 100,000 times faster than numerical integration--without substantially sacrificing accuracy. This advancement is promising for efficient rock-scale IP modeling in complex and anisotropic geological settings., Comment: 25 pages, 4 tables, 11 figures, 1 appendix. Original manuscript version submitted to Geophysics
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- 2024
36. Enhance DNN Adversarial Robustness and Efficiency via Injecting Noise to Non-Essential Neurons
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Liu, Zhenyu, Gagnon, Garrett, Venkataramani, Swagath, and Liu, Liu
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Computer Science - Machine Learning ,Computer Science - Artificial Intelligence ,Computer Science - Cryptography and Security - Abstract
Deep Neural Networks (DNNs) have revolutionized a wide range of industries, from healthcare and finance to automotive, by offering unparalleled capabilities in data analysis and decision-making. Despite their transforming impact, DNNs face two critical challenges: the vulnerability to adversarial attacks and the increasing computational costs associated with more complex and larger models. In this paper, we introduce an effective method designed to simultaneously enhance adversarial robustness and execution efficiency. Unlike prior studies that enhance robustness via uniformly injecting noise, we introduce a non-uniform noise injection algorithm, strategically applied at each DNN layer to disrupt adversarial perturbations introduced in attacks. By employing approximation techniques, our approach identifies and protects essential neurons while strategically introducing noise into non-essential neurons. Our experimental results demonstrate that our method successfully enhances both robustness and efficiency across several attack scenarios, model architectures, and datasets.
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- 2024
37. Cosmological Constraints from Combining Galaxy Surveys and Gravitational Wave Observatories
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Gagnon, E. L., Anbajagane, D., Prat, J., Chang, C., and Frieman, J.
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Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
Spatial variations in survey properties due to selection effects generate substantial systematic errors in large-scale structure measurements in optical galaxy surveys on very large scales. On such scales, the statistical sensitivity of optical surveys is also limited by their finite sky coverage. By contrast, gravitational wave (GW) sources appear to be relatively free of these issues, provided the angular sensitivity of GW experiments can be accurately characterized. We quantify the expected cosmological information gain from combining the forecast LSST 3$\times$2pt analysis (combination of three 2-point correlations of galaxy density and weak lensing shear fields) with the large-scale auto-correlation of GW sources from proposed next-generation GW experiments. We find that in $\Lambda$CDM and $w$CDM models, there is no significant improvement in cosmological constraints from combining GW with LSST 3$\times$2pt over LSST alone, due to the large shot noise for the former; however, this combination does enable a $\sim6\%$ constraint on the linear galaxy bias of GW sources. More interestingly, the optical-GW data combination provides tight constraints on models with primordial non-Gaussianity (PNG), due to the predicted scale-dependent bias in PNG models on large scales. Assuming that the largest angular scales that LSST will probe are comparable to those in Stage III surveys ($\ell_{\rm min}\sim50$), the inclusion of next-generation GW measurements could improve constraints on the PNG parameter $f_{\rm NL}$ by up to a factor of $\simeq6.6$ compared to LSST alone, yielding $\sigma(f_{\rm NL})=8.5$. These results assume the expected capability of a network of Einstein Telescope-like GW observatories, with a detection rate of $10^6$ events/year. We investigate the sensitivity of our results to different assumptions about future GW detectors as well as different LSST analysis choices., Comment: 16 pages, 8 figures, 5 tables
- Published
- 2023
38. A Research-Based Literacy Instruction MTSS for Juvenile Correctional Facilities
- Author
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David E. Houchins, Richard G. Lambert, Christopher Henrich, and Joseph Calvin Gagnon
- Abstract
A major challenge for juvenile correctional facilities (JCF) is providing literacy instruction to a transitory student population with a wide range of literacy abilities. The purpose of this study was to identify unique literacy profiles of students in long-term JCF taking into consideration their reading abilities, language abilities, intelligence quotient (IQ), disability classification, age, and grade level. Using latent profile analyses with a sample of 370 in the southeastern United States, we identified three distinct classes. Three ability groups of students (average literacy abilities, below-average literacy abilities, substantially below-average literacy abilities) were identified. Thirty-six percent performed at the average level, 55% performed below grade level; and 8% had substantial literacy deficits with an overrepresentation of students with emotional disturbance (ED) and specific learning disability (SLD). Findings provide the foundation for an evidence-based multi-tiered system of supports literacy framework within JCF. Instructional implications concerning the provision of English Language Arts in JCF are provided.
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- 2024
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39. The role of vestibular function on the vestibulo-sympathetic reflex recovery among children following moderate to severe traumatic brain injury
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Sorek, Gilad, Gagnon, Isabelle, Schneider, Kathryn, Chevignard, Mathilde, Stern, Nurit, Fadida, Yahaloma, Kalderon, Liran, Shaklai, Sharon, and Katz-Leurer, Michal
- Published
- 2024
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40. Photometry of Type II Supernova SN 2023ixf with a Worldwide Citizen Science Network
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Sgro, Lauren A., Esposito, Thomas M., Blaclard, Guillaume, Gomez, Sebastian, Marchis, Franck, Filippenko, Alexei V., Peluso, Daniel O'Conner, Lawrence, Stephen S., Verveen, Aad, Wagner, Andreas, Nardi, Anouchka, Wiart, Barbara, Mirwald, Benjamin, Christensen, Bill, Eramia, Bob, Parker, Bruce, Guillet, Bruno, Kim, Byungki, Logan, Chelsey A., Kyba, Christopher C. M., Toulmin, Christopher, Vantaggiato, Claudio G., Adhis, Dana, Gary, Dave, Goodey, Dave, Dickinson, David, Koster, David, Martin, Davy, Bonilla, Eliud, Chung, Enner, Miny, Eric, Mortecrette, Fabrice, Saibi, Fadi, Gagnon, Francois O., Simard, François, Vacon, Gary, Simard, Georges, Dreise, Gerrit, Funakoshi, Hiromi, Vacon, Janet, Yaniz, James, Tarnec, Jean-Charles Le, Laugier, Jean-Marie, Siders, Jennifer L. W., Sweitzer, Jim, Dvoracek, Jiri, Archer, John, Deitz, John, Bradley, John K., Fukui, Keiichi, Sibbernsen, Kendra, Borrot, Kevin, Cross, Kevin, Heider, Kevin, Yamaguchi, Koichi, Hirsch, Lea A., Leroux, Liouba, Billiani, Mario, Lorber, Markus, Smallen, Martin J., Shimizu, Masao, Nishimura, Masayoshi, Ryno, Matthew, Cunningham, Michael, Gagnon, Michael, Primm, Michael, Rushton, Michael, Sibbernsen, Michael, Mitchell, Mike, Yoblonsky, Neil, Leroux, Niniane, Clerget, Olivier, Stojanović, Ozren, Unique, Patrice, Huth, Patrick, Ang, Raymund John, Santoni, Regis, Foster, Robert, Poggiali, Roberto, Xu, Ruyi, Kukita, Ryuichi, Šćepanović, Sanja, Saibi, Sophie, Will, Stefan, Latour, Stephan, Haythornthwaite, Stephen, Cadieux, Sylvain, Müller, Thoralf, Chung, Tze Yang, Watanabe, Yoshiya, and Arnaud, Yvan
- Subjects
Astrophysics - High Energy Astrophysical Phenomena - Abstract
We present highly sampled photometry of the supernova (SN) 2023ixf, a Type II SN in M101, beginning 2 days before its first known detection. To gather these data, we enlisted the global Unistellar Network of citizen scientists. These 252 observations from 115 telescopes show the SN's rising brightness associated with shock emergence followed by gradual decay. We measure a peak $M_{V}$ = -18.18 $\pm$ 0.09 mag at 2023-05-25 21:37 UTC in agreement with previously published analyses., Comment: 4 pages, 1 figure
- Published
- 2023
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41. Using Auxiliary Data to Boost Precision in the Analysis of A/B Tests on an Online Educational Platform: New Data and New Results
- Author
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Sales, Adam C., Prihar, Ethan B., Gagnon-Bartsch, Johann A., and Heffernan, Neil T.
- Abstract
Randomized A/B tests within online learning platforms represent an exciting direction in learning sciences. With minimal assumptions, they allow causal effect estimation without confounding bias and exact statistical inference even in small samples. However, often experimental samples and/or treatment effects are small, A/B tests are underpowered, and effect estimates are overly imprecise. Recent methodological advances have shown that power and statistical precision can be substantially boosted by coupling design-based causal estimation to machine-learning models of rich log data from historical users who were not in the experiment. Estimates using these techniques remain unbiased and inference remains exact without any additional assumptions. This paper reviews those methods and applies them to a new dataset including over 250 randomized A/B comparisons conducted within ASSISTments, an online learning platform. We compare results across experiments using four novel deep-learning models of auxiliary data and show that incorporating auxiliary data into causal estimates is roughly equivalent to increasing the sample size by 20% on average, or as much as 50-80% in some cases, relative to t-tests, and by about 10% on average, or as much as 30-50%, compared to cutting-edge machine learning unbiased estimates that use only data from the experiments. We show that the gains can be even larger for estimating subgroup effects, hold even when the remnant is unrepresentative of the A/B test sample, and extend to post-stratification population effects estimators.
- Published
- 2023
42. The gifts of multiple perspectives: a Two-Eyed Seeing approach to Gumegwsis (Cyclopterus lumpus) ecology in inner Mawipoqtapei (Chaleur Bay), Eastern Canada
- Author
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Gillis, Carole-Anne, Gagnon, Catherine-Alexandra, Chiasson, Billie, Gosselin, Pascale, Arsenault, Lloyd, and Vicaire, John M.
- Published
- 2024
- Full Text
- View/download PDF
43. Wood-derived biochar as a matrix for cost-effective and high-performing composite thermal energy storage materials
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Kouchachvili, Lia, Gagnon-Caya, Guillaume, and Djebbar, Reda
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- 2024
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44. Long-term severe hypoxia adaptation induces non-canonical EMT and a novel Wilms Tumor 1 (WT1) isoform
- Author
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Quenneville, Jordan, Feghaly, Albert, Tual, Margaux, Thomas, Kiersten, Major, François, and Gagnon, Etienne
- Published
- 2024
- Full Text
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45. An assessment of federal alcohol policies in Canada and priority recommendations: Results from the 3rd Canadian Alcohol Policy Evaluation Project
- Author
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Farkouh, Elizabeth K., Vallance, Kate, Wettlaufer, Ashley, Giesbrecht, Norman, Asbridge, Mark, Farrell-Low, Amanda M., Gagnon, Marilou, Price, Tina R., Priore, Isabella, Shelley, Jacob, Sherk, Adam, Shield, Kevin D., Solomon, Robert, Stockwell, Tim R., Thompson, Kara, Vishnevsky, Nicole, and Naimi, Timothy S.
- Published
- 2024
- Full Text
- View/download PDF
46. Examining Patient- and Community-Level Factors Associated with Pediatric Mental Healthcare Access Within a Patient Navigation Program
- Author
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Koob, Caitlin, Stuenkel, Mackenzie, Gagnon, Ryan J., Griffin, Sarah F., and Sease, Kerry
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- 2024
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47. Toward a Better Understanding of Walking Speed in Ataxia of Charlevoix-Saguenay: a Factor Exploratory Study
- Author
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Lessard, Isabelle, Hébert, Luc J., St-Gelais, Raphaël, Côté, Isabelle, Mathieu, Jean, Brais, Bernard, and Gagnon, Cynthia
- Published
- 2024
- Full Text
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48. The Intensity of Formal Child-Care Attendance Decreases the Shared Environment Contribution to School Readiness: A Twin Study
- Author
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Gagnon, Eloi, Boivin, Michel, Mimeau, Catherine, Feng, Bei, Morneau-Vaillancourt, Genevieve, Aubé, Sophie, Brendgen, Mara, Vitaro, Frank, and Dionne, Ginette
- Published
- 2024
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49. Invertebrate Responses to Large- and Small-Scale Drivers in Coastal Phragmites australis Beds in the Northern Baltic Sea
- Author
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Eveleens Maarse, Floriaan, Gagnon, Karine, Snickars, Martin, and Salovius-Laurén, Sonja
- Published
- 2024
- Full Text
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50. A Penguin is Not a Giraffe: Categorizing Preschool Children According to Temperament
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Maine, Jana, Huelsman, Timothy J., Gagnon, Sandra Glover, Webb, Rose Mary, and Kidder-Ashley, Pamela
- Published
- 2024
- Full Text
- View/download PDF
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