Publications

Towards whole-genome inference of polygenic scores with fast and memory-efficient algorithms
Shadi Zabad
Chirayu Anant Haryan
Simon Gravel
Sanchit Misra
Yuemei Li
2025-01-21
bioRxiv (preprint)
doi.org
A Unifying Framework for Action-Conditional Self-Predictive Reinforcement Learning
Khimya Khetarpal
Zhaohan Daniel Guo
Bernardo Avila Pires
Yunhao Tang
Clare Lyle
Mark Rowland
Nicolas Heess
Diana Borsa
Arthur Guez
Will Dabney
2025-01-21
aistats.org/AISTATS/2025/Conference (poster)
doi.org
proceedings.mlr.press
Enhancing Privacy in the Early Detection of Sexual Predators Through Federated Learning and Differential Privacy
Khaoula Chehbouni
Martine De Cock
Gilles Caporossi
Afaf Taïk
Reihaneh Rabbany
Golnoosh Farnadi
The increased screen time and isolation caused by the COVID-19 pandemic have led to a significant surge in cases of online grooming, which i… (see more)s the use of strategies by predators to lure children into sexual exploitation. Previous efforts to detect grooming in industry and academia have involved accessing and monitoring private conversations through centrally-trained models or sending private conversations to a global server. In this work, we implement a privacy-preserving pipeline for the early detection of sexual predators. We leverage federated learning and differential privacy in order to create safer online spaces for children while respecting their privacy. We investigate various privacy-preserving implementations and discuss their benefits and shortcomings. Our extensive evaluation using real-world data proves that privacy and utility can coexist with only a slight reduction in utility.
2025-01-20
ArXiv (preprint)
doi.org
arxiv.org
Supervised Large Neighbourhood Search for MIPs
Charly Robinson La Rocca
Jean-François Cordeau
Emma Frejinger
Large Neighbourhood Search (LNS) is a powerful heuristic framework for solving Mixed-Integer Programming (MIP) problems. However, designing … (see more)effective variable selection strategies in LNS remains challenging, especially for diverse sets of problems. In this paper, we propose an approach that integrates Machine Learning (ML) within the destroy operator of LNS for MIPs with a focus on minimal offline training. We implement a modular LNS matheuristic as a test bench to compare different LNS heuristics, including our ML-enhanced LNS. Experimental results on the MIPLIB 2017 dataset demonstrate that the matheuristic can significantly improve the performance of state-of-the-art solvers like Gurobi and SCIP. We conduct analyses on noisy oracles to explore the impact of prediction accuracy on solution quality. Additionally, we develop techniques to enhance the ML model through loss adjustments and sampling routines. Our findings suggest that while random LNS remains competitive, our Supervised LNS (SLNS) outperforms other baselines and helps set the foundation for future research on ML for LNS methods that are both efficient and general.
2025-01-17
ArXiv (preprint)
arxiv.org
arxiv.org
CHIRP: A Fine-Grained Benchmark for Open-Ended Response Evaluation in Vision-Language Models
Alexis Roger
Prateek Humane
Daniel Z Kaplan
Kshitij Gupta
Qirui Sun
George Adamopoulos
Jonathan Siu Chi Lim
Quentin Gregory Anthony
Edwin Fennell
Irina Rish
The proliferation of Vision-Language Models (VLMs) in the past several years calls for rigorous and comprehensive evaluation methods and ben… (see more)chmarks. This work analyzes existing VLM evaluation techniques, including automated metrics, AI-based assessments, and human evaluations across diverse tasks. We first introduce Robin - a novel suite of VLMs that we built by combining Large Language Models (LLMs) and Vision Encoders (VEs) at multiple scales, and use Robin to identify shortcomings of current evaluation approaches across scales. Next, to overcome the identified limitations, we introduce CHIRP - a new long form response benchmark we developed for more robust and complete VLM evaluation. We provide open access to the Robin training code, model suite, and CHIRP benchmark to promote reproducibility and advance VLM research.
2025-01-15
ArXiv (preprint)
doi.org
arxiv.org
AfriHate: A Multilingual Collection of Hate Speech and Abusive Language Datasets for African Languages
Shamsuddeen Hassan Muhammad
Idris Abdulmumin
Abinew Ayele
David Ifeoluwa Adelani
Ibrahim Ahmad
Saminu Mohammad Aliyu
Nelson Odhiambo Onyango
Lilian D. A. Wanzare
Samuel Rutunda
Lukman Jibril Aliyu
Esubalew Alemneh
Oumaima Hourrane
Hagos Gebremichael
Elyas Abdi Ismail
Meriem Beloucif
Ebrahim Chekol Jibril
Andiswa Bukula
Rooweither Mabuya
Salomey Osei
Abigail Oppong … (see 7 more)
Tadesse Belay
Tadesse Kebede Guge
Tesfa Tegegne Asfaw
Chiamaka Ijeoma Chukwuneke
Paul Rottger
Seid Muhie Yimam
Nedjma OUSIDHOUM
Hate speech and abusive language are global phenomena that need socio-cultural background knowledge to be understood, identified, and modera… (see more)ted. However, in many regions of the Global South, there have been several documented occurrences of (1) absence of moderation and (2) censorship due to the reliance on keyword spotting out of context. Further, high-profile individuals have frequently been at the center of the moderation process, while large and targeted hate speech campaigns against minorities have been overlooked. These limitations are mainly due to the lack of high-quality data in the local languages and the failure to include local communities in the collection, annotation, and moderation processes. To address this issue, we present AfriHate: a multilingual collection of hate speech and abusive language datasets in 15 African languages. Each instance in AfriHate is annotated by native speakers familiar with the local culture. We report the challenges related to the construction of the datasets and present various classification baseline results with and without using LLMs. The datasets, individual annotations, and hate speech and offensive language lexicons are available on https://github.com/AfriHate/AfriHate
2025-01-13
ArXiv (preprint)
doi.org
arxiv.org
Integrating food webs in species distribution models can improve ecological niche estimation and predictions
Giovanni Poggiato
Jérémy Andréoletti
Laura J. Pollock
Wilfried Thuiller
2025-01-13
Ecography (published)
doi.org
Multi-agent deep reinforcement learning with online and fair optimal dispatch of EV aggregators
Arian Shah Kamrani
Anoosh Dini
Hanane Dagdougui
Keyhan Sheshyekani
The growing popularity of electric vehicles (EVs) and the unpredictable behavior of EV owners have attracted attention to real-time coordina… (see more)tion of EVs charging management. This paper presents a hierarchical structure for charging management of EVs by integrating fairness and efficiency concepts within the operations of the distribution system operator (DSO) while utilizing a multi-agent deep reinforcement learning (MADRL) framework to tackle the complexities of energy purchasing and distribution among EV aggregators (EVAs). At the upper level, DSO calculates the maximum allowable power for each EVA based on power flow constraints to ensure grid safety. Then, it finds the optimal efficiency-jain tradeoff (EJT) point, where it sells the highest energy amount while ensuring equitable energy distribution. At the lower level, initially, each EVA acts as an agent employing a double deep Q-network (DDQN) with adaptive learning rates and prioritized experience replay to determine optimal energy purchases from the DSO. Then, the real-time smart dispatch (RSD) controller prioritizes EVs for energy dispatch based on relevant EVs information. Findings indicate the proposed enhanced DDQN outperforms deep deterministic policy gradient (DDPG) and proximal policy optimization (PPO) in cumulative rewards and convergence speed. Finally, the framework’s performance is evaluated against uncontrolled charging and the first come first serve (FCFS) scenario using the 118-bus distribution system, demonstrating superior performance in maintaining safe operation of the grid while reducing charging costs for EVAs. Additionally, the framework’s integration with renewable energy sources (RESs), such as photovoltaic (PV), demonstrates its potential to enhance grid reliability. • Introduces a scalable MADRL framework for real-time EV charging and energy distribution. • Ensures fairness via an Efficiency-Jain Tradeoff (EJT) strategy at the DSO level. • Enhances agent convergence with DDQN using adaptive learning rates and prioritized replay. • Preserves stakeholder privacy with decentralized control and minimal data sharing. • Balances grid reliability with equitable energy allocation under dynamic uncertainties.
2025-01-08
Machine Learning with Applications (published)
doi.org
Open Problems in Machine Unlearning for AI Safety
Fazl Barez
Tingchen Fu
Ameya Prabhu
Stephen Casper
Amartya Sanyal
Adel Bibi
Aidan O'Gara
Robert Kirk
Benjamin Bucknall
Timothy Fist
Luke Ong
Philip Torr
Kwok-Yan Lam
Robert Trager
David M. Krueger
Sören Mindermann
Jose Hernandez-Orallo
Mor Geva
Yarin Gal
As AI systems become more capable, widely deployed, and increasingly autonomous in critical areas such as cybersecurity, biological research… (see more), and healthcare, ensuring their safety and alignment with human values is paramount. Machine unlearning -- the ability to selectively forget or suppress specific types of knowledge -- has shown promise for privacy and data removal tasks, which has been the primary focus of existing research. More recently, its potential application to AI safety has gained attention. In this paper, we identify key limitations that prevent unlearning from serving as a comprehensive solution for AI safety, particularly in managing dual-use knowledge in sensitive domains like cybersecurity and chemical, biological, radiological, and nuclear (CBRN) safety. In these contexts, information can be both beneficial and harmful, and models may combine seemingly harmless information for harmful purposes -- unlearning this information could strongly affect beneficial uses. We provide an overview of inherent constraints and open problems, including the broader side effects of unlearning dangerous knowledge, as well as previously unexplored tensions between unlearning and existing safety mechanisms. Finally, we investigate challenges related to evaluation, robustness, and the preservation of safety features during unlearning. By mapping these limitations and open challenges, we aim to guide future research toward realistic applications of unlearning within a broader AI safety framework, acknowledging its limitations and highlighting areas where alternative approaches may be required.
2025-01-08
ArXiv (preprint)
doi.org
arxiv.org
Soup to go: mitigating forgetting during continual learning with model averaging
Anat Kleiman
Gintare Karolina Dziugaite
Jonathan Frankle
Sham M. Kakade
Mansheej Paul
In continual learning, where task data arrives in a sequence, fine-tuning on later tasks will often lead to performance degradation on earli… (see more)er tasks. This is especially pronounced when these tasks come from diverse domains. In this setting, how can we mitigate catastrophic forgetting of earlier tasks and retain what the model has learned with minimal computational expenses? Inspired by other merging methods, and L2-regression, we propose Sequential Fine-tuning with Averaging (SFA), a method that merges currently training models with earlier checkpoints during the course of training. SOTA approaches typically maintain a data buffer of past tasks or impose a penalty at each gradient step. In contrast, our method achieves comparable results without the need to store past data, or multiple copies of parameters for each gradient step. Furthermore, our method outperforms common merging techniques such as Task Arithmetic, TIES Merging, and WiSE-FT, as well as other penalty methods like L2 and Elastic Weight Consolidation. In turn, our method offers insight into the benefits of merging partially-trained models during training across both image and language domains.
2025-01-08
ArXiv (preprint)
doi.org
openreview.net
Adaptive Experiments Under Data Sparse Settings: Applications for Educational Platforms
Haochen Song
Ilya Musabirov
Ananya Bhattacharjee
Audrey Durand
Meredith Franklin
Anna Rafferty
Joseph Jay Williams
Adaptive experimentation is increasingly used in educational platforms to personalize learning through dynamic content and feedback. However… (see more), standard adaptive strategies such as Thompson Sampling often underperform in real-world educational settings where content variations are numerous and student participation is limited, resulting in sparse data. In particular, Thompson Sampling can lead to imbalanced content allocation and delayed convergence on which aspects of content are most effective for student learning. To address these challenges, we introduce Weighted Allocation Probability Adjusted Thompson Sampling (WAPTS), an algorithm that refines the sampling strategy to improve content-related decision-making in data-sparse environments. WAPTS is guided by the principle of lenient regret, allowing near-optimal allocations to accelerate learning while still exploring promising content. We evaluate WAPTS in a learnersourcing scenario where students rate peer-generated learning materials, and demonstrate that it enables earlier and more reliable identification of promising treatments.
2025-01-06
ArXiv (preprint)
arxiv.org
arxiv.org
L’appréhension empirique du leadership normatif d’une organisation internationale : l’exemple de l’Organisation mondiale de la Santé
Catherine Régis
Gaëlle Foucault
Pierre Larouche
Jean-Louis Denis
Miriam Cohen
En plein essor, la recherche empirique en droit participe à la création de nouvelles connaissances et ouvre aux juristes d’autres voies … (see more)pour étudier une question, un phénomène. Oser l’empirisme n’est pas chose aisée, mais les auteurs du présent article ont pris ce virage et proposent d’en exposer le récit. En construisant deux méthodes distinctes (pour deux projets), ils ont pu tester les possibilités qu’offre la recherche empirique pour appréhender l’enjeu du leadership normatif de l’Organisation mondiale de la Santé (OMS). Destiné à aiguiller à partir d’une expérience celles et ceux qui voudraient s’aventurer dans l’empirisme, cet article met en lumière les défis rencontrés, mais surtout les atouts d’une telle recherche. La richesse des informations obtenues a en effet grandement bonifié la compréhension de la trajectoire des normes de l’OMS et de leurs impacts sur les États.
2025-01-06
Lex Electronica (published)
doi.org