Yiyi Zhang

Hi, I'm Yiyi Zhang. I'm a visiting scientist in Computer Science at Cornell University and a Siyuan Fellow at Shanghai Jiao Tong University. At Cornell, I work closely with Wen Sun and Nate Foster. My research focuses on reinforcement learning, particularly its theoretical foundations and applications to LLMs and cybersecurity.

I received Ph.D. degrees in Computer Science from Shanghai Jiao Tong University and The University of Osaka through a double-degree program. My doctoral research focused on generative models for gait under the supervision of Liqing Zhang and Yasushi Yagi. Prior to that, I obtained my bachelor's degree in Computer Science from Shanghai Jiao Tong University, where I was a member of the ACM Honors Class.

Yiyi Zhang
Selected

Exploring the Efficacy of Multi-Agent Reinforcement Learning for Autonomous Cyber Defence: A CAGE Challenge 4 Perspective

Mitchell Kiely, Metin Ahiskali, Etienne Borde, Benjamin Bowman, David Bowman, Dirk van Bruggen, KC Cowan, Prithviraj Dasgupta, Erich Devendorf, Ben Edwards, Alex Fitts, Sunny Fugate, Ryan Gabrys, Wayne Gould, H. Howie Huang, Jules Jacobs, Ryan Kerr, Isaiah J. King, Li Li, Luis Martinez, Christopher Moir, Craig Murphy, Olivia Naish, Claire Owens, Miranda Purchase, Ahmad Ridley, Adrian Taylor, Sara Farmer, William John Valentine, Yiyi Zhang

AAAI, 2025

For citations and the latest publication list, visit my Google Scholar profile.

Experience

Cornell University

Visiting Scientist · Computer Science

Reinforcement learning and LLM agents for autonomous cyber defense.

Jan. 2024 – Present

Shanghai Jiao Tong University

Postdoctoral Researcher · Department of Computer Science

Identity-preserving gait generation and mixed-reality behavioral data collection.

Dec. 2022 – Dec. 2023

Versa Inc.

Algorithm Engineer

Developed and deployed an image matting algorithm for Makaron, an app serving 200M+ active users.

Feb. 2019 – Sept. 2019

Microsoft Research Asia

Stars of Tomorrow Research Intern · Urban Computing Group

Built and deployed a policy evaluation module for Urban Air, using machine learning to predict air quality across 300+ cities.

Aug. 2016 – June 2017

Education

The University of Osaka

Ph.D. in Computer Science (Double Degree Program)

Oct. 2019 – Dec. 2022

Shanghai Jiao Tong University

Ph.D. in Computer Science

Sept. 2017 – Dec. 2022

Cornell University

Exchange Student · Computer Science

Aug. 2017 – Aug. 2018

Shanghai Jiao Tong University

B.Eng. in Computer Science (Honor)

ACM Honors Class · Outstanding Graduate

Sept. 2013 – July 2017

Academic Service & Honors

Reviewer: NeurIPS and ICLR (2025–2026); CVPR, ECCV, and AAAI (2020–2026); IJCAI (2020–2025).