I am a Ph.D. student in Computer Science at the University of California, Los Angeles, advised by Prof. Guy Van den Broeck in the StarAI Lab. I go by Zoe.
My research integrates tractable probabilistic models into modern neural architectures to improve the training efficiency, inference quality, and controllability of deep generative models. I also develop optimization techniques for probabilistic and generative models, spanning parameter learning, low-variance gradient estimation, and differentiable routing in large-scale architectures. In a related line of work, I study tokenization in Large Language Models (LLMs) as a neurosymbolic problem, showing that non-canonical tokenizations of the same input can substantially change model behavior, with the broader goal of making these large-scale systems more tractable and reliable.
Before my doctoral studies, I earned my Bachelor of Science degree in a joint major of Computer Science and Mathematics at Harvey Mudd College, where I was deeply involved in bounding-box inference within the context of model-based Reinforcement Learning under the supervision of Prof. Erin Talvitie.

Ian Li*, Zilei Shao*, Benjie Wang, Rose Yu, Guy Van den Broeck, Anji Liu (* equal contribution)
International Conference on Machine Learning (ICML) 2026
Diffusion language models generate many tokens at once but assume they are independent, which costs coherence. CoDD replaces that factorized output with a lightweight tractable inference layer, keeping quality even at very few decoding steps.
Ian Li*, Zilei Shao*, Benjie Wang, Rose Yu, Guy Van den Broeck, Anji Liu (* equal contribution)
International Conference on Machine Learning (ICML) 2026
Diffusion language models generate many tokens at once but assume they are independent, which costs coherence. CoDD replaces that factorized output with a lightweight tractable inference layer, keeping quality even at very few decoding steps.

Anji Liu, Zilei Shao, Guy Van den Broeck
International Conference on Artificial Intelligence and Statistics (AISTATS) 2026 Oral
Full-batch EM for probabilistic circuits is too slow on large datasets, and mini-batch variants overfit each batch. anemone is a mini-batch EM algorithm with an implicit per-parameter adaptive learning rate that converges faster and reaches better likelihoods.
Anji Liu, Zilei Shao, Guy Van den Broeck
International Conference on Artificial Intelligence and Statistics (AISTATS) 2026 Oral
Full-batch EM for probabilistic circuits is too slow on large datasets, and mini-batch variants overfit each batch. anemone is a mini-batch EM algorithm with an implicit per-parameter adaptive learning rate that converges faster and reaches better likelihoods.

Zilei Shao, Anji Liu, Guy Van den Broeck
NeurIPS Workshop on Structured Probabilistic Inference & Generative Modeling (SPIGM) 2025 Best Poster Award
Training a VAE normally requires noisy Monte Carlo gradient estimates. This work shows that with a suitably restricted decoder the expected ELBO can be computed analytically, giving gradients with zero estimation variance and better early optimization.
Zilei Shao, Anji Liu, Guy Van den Broeck
NeurIPS Workshop on Structured Probabilistic Inference & Generative Modeling (SPIGM) 2025 Best Poster Award
Training a VAE normally requires noisy Monte Carlo gradient estimates. This work shows that with a suitably restricted decoder the expected ELBO can be computed analytically, giving gradients with zero estimation variance and better early optimization.

Renato L. Geh*, Zilei Shao*, Guy Van den Broeck (* equal contribution)
Annual Meeting of the Association for Computational Linguistics (ACL), Main Conference, 2025
The same string can be tokenized in exponentially many valid ways, and LLMs still understand the non-canonical ones. Simply re-tokenizing a prompt, without changing a single character, is enough to bypass safety alignment in state-of-the-art models.
Renato L. Geh*, Zilei Shao*, Guy Van den Broeck (* equal contribution)
Annual Meeting of the Association for Computational Linguistics (ACL), Main Conference, 2025
The same string can be tokenized in exponentially many valid ways, and LLMs still understand the non-canonical ones. Simply re-tokenizing a prompt, without changing a single character, is enough to bypass safety alignment in state-of-the-art models.