Julia Romero in front of the Flatirons

Julia Romero, PhD

AI/ML Research Scientist

Computer Vision Self-Supervised Learning Multimodal Models Geospatial AI

I am seeking Research Scientist roles in AI/ML, especially in computer vision, foundation models and self-supervised learning, and sensing systems.

About Me

I recently completed my PhD in Computer Science at the University of Colorado Boulder. I build effective and efficient AI/ML approaches for spatiotemporal vision, multimodal, and sensor data, with applications in geospatial AI, video understanding, and ubiquitous computing. My work focuses on supervised and self-supervised learning, multimodal modeling, and practical approaches for real-world use. Specifically, my research has spanned these topics:

  • Vision & Geospatial Foundation Models: I develop and interpret self-supervised vision foundation models for Earth observation tasks, examining pretraining, transfer learning, and downstream adaptation. For this work, I implemented and maintained multi-cluster distributed computing infrastructure on an NSF supercomputer [under review, 2026].
  • Multimodal Video Understanding: I build lightweight and flexible graph-based vision models for fine-grained activity recognition. Our framework can be trained on multimodal and multi-view (multiple cameras) data while only requiring a single input for inference [ICCVW 2025]. This work with Intel Labs won 1st place out fo 20+ teams in the Ego-Exo4D Keystep Recognition challenge (sponsored by Meta) and led to an invited spotlight talk at the CVPR 2025 Egocentric Vision Workshop.
  • Human-Centered Sensing Systems: I design sensing algorithms for resource-constrained wearables and ML pipelines for health and fitness data, spanning physiological monitoring with smart earbuds [HotMobile 2024], injury-risk modeling from wearables data, activity recognition with motion sensors [Sensors 2023], and large-scale physical-activity behavior analysis [IJERPH 2022].

My PhD research was funded in part by an NSF IUCRC award from a proposal I co-wrote, which supported a collaboration with Intel Labs from 2023 to 2025. During my PhD, I was also a research intern at Nokia Bell Labs in Cambridge, UK and worked on wearable computing and health ML at Stryd, Kinesis Integrated, and the Johns Hopkins Applied Physics Laboratory.

Recent News

Defended my Ph.D. dissertation, Effective and Efficient Machine Learning for Sensor Data: From Wearable Sensing to Earth Observation!

Submitted first-author work on self-supervised geospatial foundation models to ACM SIGSPATIAL.

Presented our graph-based keystep recognition paper at the ICCV 2025 Workshop on Scene Graphs and Graph Representation Learning.

Won 1st place (out of 20+ teams) in the Ego-Exo4D Keystep Recognition Challenge and gave an invited spotlight talk at the CVPR Egocentric Vision Workshop.

Presented OptiBreathe at ACM HotMobile 2024 and filed two related patent applications with Nokia Bell Labs.

Research intern in the Pervasive Systems group at Nokia Bell Labs (Cambridge, UK), working on respiratory sensing from in-ear PPG.

Awarded NSF IUCRC funding for our proposal on graph representation learning, launching a 2.5-year collaboration with Intel Labs.

Publications

Teaser thumbnail for self-supervised geospatial transfer work

Julia L. Romero, Q. Lv, M. Karimzadeh.

“How do Self-Supervised Remote Sensing Vision Models Transfer to Downstream Tasks?”

arXiv preprint, 2026. Under review at ACM SIGSPATIAL.

Teaser thumbnail for graph-based keystep recognition paper

Julia L. Romero, K. Min, S. Tripathi, M. Karimzadeh.

“Long-form Reasoning for Keystep Recognition using Graph Neural Networks.”

International Conference on Computer Vision Workshops (ICCVW), 2025

1st place, Meta's Ego-Exo4D Keystep Recognition Challenge for Video Understanding

Invited spotlight talk @ CVPR Egocentric Vision Workshop, 2025

Teaser thumbnail for OptiBreathe paper

Julia L. Romero, A. Ferlini, D. Spathis, T. Dang, K. Farrahi, F. Kawsar, A. Montanari.

“OptiBreathe: An Earable-based PPG System for Continuous Respiration Rate, Breathing Phase, and Tidal Volume Monitoring.”

International Workshop on Mobile Computing Systems and Applications (HotMobile), 2024

Teaser thumbnail for basketball activity recognition paper

A. Hoelzemann, Julia L. Romero, M. Bock, K. Van Laerhoven, Q. Lv.

“Hang-Time HAR: A Dataset for Basketball Activity Recognition Using Wrist-Worn Inertial Sensors.”

Sensors, 2023

Teaser thumbnail for physical activity habits paper

Julia L. Romero, Q. Lv.

“Global Impact of the COVID-19 Pandemic on Physical Activity Habits of Competitive Runners: An Analysis of Wearable Device Data.”

International Journal of Environmental Research and Public Health, 2022

Patents

Personal

In my free time, I enjoy training for ultramarathons, skiing, playing soccer, and being in nature. I also enjoy playing instruments with friends, listening to music, and learning music production software.