activity
20232026
most citedContextual Stochastic Bilevel Optimization

2 citations · 4 across the 12 of their papers we have counts for

collaborators

13 papers

cs.LG2026

Dr. OPD: Learning What to Follow for Optimal On-Policy Distillation of Large Language Models

Zhenyu Wang, Tianze Wang, Linjun Zhang +1

On-policy distillation (OPD) trains a student on its own generated responses using dense, token-level supervision from a stronger teacher. Vanilla OPD treats all teacher signals eq…

cs.CV2025

CCAD: Compressed Global Feature Conditioned Anomaly Detection

Xiao Jin, Liang Diao, Qixin Xiao +4

Anomaly detection holds considerable industrial significance, especially in scenarios with limited anomalous data. Currently, reconstruction-based and unsupervised representation-b…

cs.CV2025

Unlocking the Essence of Beauty: Advanced Aesthetic Reasoning with Relative-Absolute Policy Optimization

Boyang Liu, Yifan Hu, Senjie Jin +5

Multimodal large language models (MLLMs) are well suited to image aesthetic assessment, as they can capture high-level aesthetic features leveraging their cross-modal understanding…

cs.CL2025

Entropy-Driven Pre-Tokenization for Byte-Pair Encoding

Yifan Hu, Frank Liang, Dachuan Zhao +4

Byte-Pair Encoding (BPE) has become a widely adopted subword tokenization method in modern language models due to its simplicity and strong empirical performance across downstream…

stat.ML2025

Reinforcement Learning with Continuous Actions Under Unmeasured Confounding

Yuhan Li, Eugene Han, Yifan Hu +4

This paper addresses the challenge of offline policy learning in reinforcement learning with continuous action spaces when unmeasured confounders are present. While most existing r…

cs.LG2025

Global Group Fairness in Federated Learning via Function Tracking

Yves Rychener, Daniel Kuhn, Yifan Hu

We investigate group fairness regularizers in federated learning, aiming to train a globally fair model in a distributed setting. Ensuring global fairness in distributed training p…

cs.CL2025

MPO: An Efficient Post-Processing Framework for Mixing Diverse Preference Alignment

Tianze Wang, Dongnan Gui, Yifan Hu +2

Reinforcement Learning from Human Feedback (RLHF) has shown promise in aligning large language models (LLMs). Yet its reliance on a singular reward model often overlooks the divers…

cs.DC2025★ 1 cited

Efficiently Serving Large Multimodal Models Using EPD Disaggregation

Gursimran Singh, Xinglu Wang, Yifan Hu +9

Large Multimodal Models (LMMs) extend Large Language Models (LLMs) by handling diverse inputs such as images, audio, and video, but at the cost of adding a multimodal encoding stag…

math.OC2024

Contextual Bilevel Reinforcement Learning for Incentive Alignment

Vinzenz Thoma, Barna Pasztor, Andreas Krause +2

The optimal policy in various real-world strategic decision-making problems depends both on the environmental configuration and exogenous events. For these settings, we introduce C…

cs.CL2024

Group Robust Preference Optimization in Reward-free RLHF

Shyam Sundhar Ramesh, Yifan Hu, Iason Chaimalas +4

Adapting large language models (LLMs) for specific tasks usually involves fine-tuning through reinforcement learning with human feedback (RLHF) on preference data. While these data…

stat.ML2024

Stochastic Optimization Algorithms for Instrumental Variable Regression with Streaming Data

Xuxing Chen, Abhishek Roy, Yifan Hu +1

We develop and analyze algorithms for instrumental variable regression by viewing the problem as a conditional stochastic optimization problem. In the context of least-squares inst…

math.OC2023★ 2 cited

Contextual Stochastic Bilevel Optimization

Yifan Hu, Jie Wang, Yao Xie +2

We introduce contextual stochastic bilevel optimization (CSBO) -- a stochastic bilevel optimization framework with the lower-level problem minimizing an expectation conditioned on…

cs.LG2023★ 1 cited

Distributionally Robust Model-based Reinforcement Learning with Large State Spaces

Shyam Sundhar Ramesh, Pier Giuseppe Sessa, Yifan Hu +2

Three major challenges in reinforcement learning are the complex dynamical systems with large state spaces, the costly data acquisition processes, and the deviation of real-world d…