Yihang Chen

Yihang Chen 陈奕行

I am a PhD student in computer science at UCLA, advised by Prof. Cho-Jui Hsieh. I received my bachelor degree in computational mathematics at Peking University in July 2021, advised by Prof. Liwei Wang; and my master degree in data science at EPFL in February 2024, advised by Prof. Volkan Cevher.

Email / CV / Google Scholar / Twitter / Github / LinkedIn

Research

I have a broad interest in large language models and other generative models. Currently, my current research mainly focus on:

LLM Safety: Jailbreaking, Membership Inference Attacks.
LLM Alignment: Preference Optimization, Parameter-Efficient Finetuning
Sampling: MCMC, Generative Flow Networks.

What's New?

[Nov 3, 2024] I am honored to be among the top reviewers of NeurIPS 2024.
[Oct 28, 2024] Our work on the multi-step preference optimization is accepted to be the oral presentation on Language Gamification Workshop @ NeurIPS 2024.
[Oct 11, 2024] I am honored to receive the NeurIPS 2024 Scholar Award with financial assistance.
[Sept 25, 2024] Our work on the privacy of large language models is accepted by NeurIPS 2024.
[Sept 23, 2024] I start my PhD at UCLA.

Publications

* indicates equal contribution

	Multi-Step Preference Optimization via Two-Player Markov Games Yongtao Wu, Luca Viano, Yihang Chen, Zhenyu Zhu, Quanquan Gu, Volkan Cevher Under review. Abridged in Language Gamification Workshop @ NeurIPS, Oral, 2024
	Membership Inference Attacks against Large Vision-Language Models Zhan Li, Yongtao Wu, Yihang Chen, Francesco Tonin, Elias Abad Rocamora, Volkan Cevher 38th Annual Conference on Neural Information Processing Systems (NeurIPS)*, 2024 [arxiv] / [code] We introduce the first membership inference attack (MIA) benchmark for VLLMs. We also propose the first cross-model MIA pipeline with a new MIA metric.
	High-Dimensional Kernel Methods under Covariate Shift: Data-Dependent Implicit Regularization Yihang Chen, Fanghui Liu, Taiji Suzuki, Volkan Cevher 41st International Conference on Machine Learning (ICML), 2024 [arxiv] / [poster] We study kernel ridge regression in high dimensions under covariate shifts and analyzes the role of importance re-weighting. We also provide asymptotic expansion of kernel functions/vectors under covariate shift.
	Order-Preserving GFlowNets Yihang Chen, Lukas Mauch 12th International Conference on Learning Representations (ICLR), 2024 [arxiv] / [code] / [poster] / [slides] We propose Order-Preserving GFlowNets (OP-GFNs), which sample composite objects given only the (partial) order. We extend GFlowNets to preference-based optimization.
	Generalization of Scaled Deep ResNets in the Mean-Field Regime Yihang Chen, Fanghui Liu, Yiping Lu, Grigorios Chrysos, Volkan Cevher 12th International Conference on Learning Representations (ICLR), Spotlight, 2024 [arxiv] / [poster] / [slides] We provide the upper bound of the parameter distribution moving and generalization error on the 0-1 classification task of the infinitely deep and wide ResNets.
	Sanity-Checking Pruning Methods: Random Tickets can Win the Jackpot Jingtong Su, Yihang Chen, Tianle Cai, Tianhao Wu, Ruiqi Gao, Liwei Wang, Jason D. Lee. 34th Annual Conference on Neural Information Processing Systems (NeurIPS)*, 2020 [arxiv] / [code] / [slides] We sanity-check prune-at-init methods, and find them hardly exploits any information from the training data. We also propose "zero-shot" pruning, which only relies on simple data-independent pruning ratios for each layer.

Miscellanea

Honors and Awards

NeurIPS 2024 Scholar Award & Top Reviewers, 2024.
Research Scholars MSc Program, EPFL, 2021-2022.
The Elite Undergraduate Training Program of Applied Math, 2019-2021.
Excellent Graduate of Peking University, 2021.
National Scholarship, People's Republic of China (Top 1%), 2020.
Shing Tung Yau Mathematics Awards, Chia Chiao Lin Medals, Bronze, 2020.

Invited Talks

Mila GFlowNet meeting, Order-Preserving GFlowNets, 2023.10.04.

Services

Conference Reviewers: NeurIPS 2024, ICLR 2025, AISTATS 2025.

Fun Facts

During my stay in Switzerland, I hiked the Via Alpina.

Last Updated: Nov 8, 2024. Website template from Jon Barron.