activity
20242026
collaborators

8 papers

cs.AI2026

Beyond RLHF and NLHF: Population-Proportional Alignment under an Axiomatic Framework

Kihyun Kim, Jiawei Zhang, Asuman Ozdaglar +1

Conventional preference learning methods often prioritize opinions held more widely when aggregating preferences from multiple evaluators. This may result in policies that are bias…

cs.LG2026

Why GRPO Needs Normalization: A Local-Curvature Perspective on Adaptive Gradients

Cheng Ge, Caitlyn Heqi Yin, Hao Liang +1

Reinforcement learning (RL) has become a key driver of language model reasoning. Among RL algorithms, Group Relative Policy Optimization (GRPO) is the de facto standard, avoiding t…

cs.LG2026

Mosaic: Unlocking Long-Context Inference for Diffusion LLMs via Global Memory Planning and Dynamic Peak Taming

Liang Zheng, Bowen Shi, Yitao Hu +5

Diffusion-based large language models (dLLMs) have emerged as a promising paradigm, utilizing simultaneous denoising to enable global planning and iterative refinement. While these…

cs.LG2025

Toward Unifying Group Fairness Evaluation from a Sparsity Perspective

Zhecheng Sheng, Jiawei Zhang, Enmao Diao

Ensuring algorithmic fairness remains a significant challenge in machine learning, particularly as models are increasingly applied across diverse domains. While numerous fairness c…

cs.AI2025

Lost in Tokenization: Context as the Key to Unlocking Biomolecular Understanding in Scientific LLMs

Kai Zhuang, Jiawei Zhang, Yumou Liu +10

Scientific Large Language Models (Sci-LLMs) have emerged as a promising frontier for accelerating biological discovery. However, these models face a fundamental challenge when proc…

stat.ME2025

Design-Based Causal Inference with Missing Outcomes: Missingness Mechanisms, Imputation-Assisted Randomization Tests, and Covariate Adjustment

Siyu Heng, Jiawei Zhang, Yang Feng

Design-based causal inference, also known as randomization-based or finite-population causal inference, is one of the most widely used causal inference frameworks, largely due to t…