collaborators

5 papers

cs.LG2026

Optimal Multiclass Online Regret with Arbitrary Label Spaces

Sajad Ashkezari, Shai Ben-David

We determine the optimal regret in agnostic multiclass online learning with arbitrary, possibly infinite, label spaces. For every hypothesis class of multiclass Littlestone dimensi…

cs.LG2026

Robust Online Learning

Sajad Ashkezari

We study the problem of learning robust classifiers where the classifier will receive a perturbed input. Unlike robust PAC learning studied in prior work, here the clean data and i…

cs.LG2026

Online Learning with Improving Agents: Multiclass, Budgeted Agents and Bandit Learners

Sajad Ashkezari, Shai Ben-David

We investigate the recently introduced model of learning with improvements, where agents are allowed to make small changes to their feature values to be warranted a more desirable…

cs.CV2025

Open-PMC-18M: A High-Fidelity Large Scale Medical Dataset for Multimodal Representation Learning

Negin Baghbanzadeh, Mohammed Saidul Islam, Sajad Ashkezari +2

In biomedical vision-language modeling, datasets are typically mined from scientific literature, pairing compound figures with captions that are short, context-dependent, and ofter…

eess.IV2025

Advancing Medical Representation Learning Through High-Quality Data

Negin Baghbanzadeh, Adibvafa Fallahpour, Yasaman Parhizkar +8

Despite the growing scale of medical Vision-Language datasets, the impact of dataset quality on model performance remains under-explored. We introduce Open-PMC, a high-quality medi…