activity
20232026
most citedChatHaruhi: Reviving Anime Character in Reality via Large Language Model

11 citations · 21 across the 18 of their papers we have counts for

collaborators

18 papers

cs.LG2026

Training Large Reasoning Models Efficiently via Progressive Thought Encoding

Zeliang Zhang, Xiaodong Liu, Hao Cheng +3

Large reasoning models (LRMs) excel on complex problems but face a critical barrier to efficiency: reinforcement learning (RL) training requires long rollouts for outcome-based rew…

cs.AI2026

Improving Interactive In-Context Learning from Natural Language Feedback

Martin Klissarov, Jonathan Cook, Diego Antognini +5

Adapting one's thought process based on corrective feedback is an essential ability in human learning, particularly in collaborative settings. In contrast, the current large langua…

cs.CV2025

ViSS-R1: Self-Supervised Reinforcement Video Reasoning

Bo Fang, Yuxin Song, Qiangqiang Wu +3

Complex video reasoning remains a significant challenge for Multimodal Large Language Models (MLLMs), as current R1-based methodologies often prioritize text-centric reasoning deri…

cs.LG2025

Why mask diffusion does not work

Haocheng Sun, Cynthia Xin Wen, Edward Hong Wang

The main advantages of diffusion language models over autoregressive (AR) models lie in their ability to support parallel generation and bidirectional attention, enabling a more co…

cs.LG2025

Inverse Reinforcement Learning Meets Large Language Model Post-Training: Basics, Advances, and Opportunities

Hao Sun, Mihaela van der Schaar

In the era of Large Language Models (LLMs), alignment has emerged as a fundamental yet challenging problem in the pursuit of more reliable, controllable, and capable machine intell…

cs.CL2025

Critique-GRPO: Advancing LLM Reasoning with Natural Language and Numerical Feedback

Xiaoying Zhang, Yipeng Zhang, Hao Sun +4

Recent advances in reinforcement learning (RL) using numerical rewards have significantly enhanced the complex reasoning capabilities of large language models (LLMs). However, we i…

cs.AI2025

Rethinking Diverse Human Preference Learning through Principal Component Analysis

Feng Luo, Rui Yang, Hao Sun +5

Understanding human preferences is crucial for improving foundation models and building personalized AI systems. However, preferences are inherently diverse and complex, making it…

cs.LG2024

Few-shot Steerable Alignment: Adapting Rewards and LLM Policies with Neural Processes

Katarzyna Kobalczyk, Claudio Fanconi, Hao Sun +1

As large language models (LLMs) become increasingly embedded in everyday applications, ensuring their alignment with the diverse preferences of individual users has become a critic…

cs.CL2024

The Synergy of LLMs & RL Unlocks Offline Learning of Generalizable Language-Conditioned Policies with Low-fidelity Data

Thomas Pouplin, Katarzyna Kobalczyk, Hao Sun +1

Developing autonomous agents capable of performing complex, multi-step decision-making tasks specified in natural language remains a significant challenge, particularly in realisti…

cs.LG2024

Inverse-RLignment: Large Language Model Alignment from Demonstrations through Inverse Reinforcement Learning

Hao Sun, Mihaela van der Schaar

Aligning Large Language Models (LLMs) is crucial for enhancing their safety and utility. However, existing methods, primarily based on preference datasets, face challenges such as…

cs.LG2024

Supervised Fine-Tuning as Inverse Reinforcement Learning

Hao Sun

The prevailing approach to aligning Large Language Models (LLMs) typically relies on human or AI feedback and assumes access to specific types of preference datasets. In our work,…

cs.CL2024★ 3 cited

Retrieval Augmented Thought Process for Private Data Handling in Healthcare

Thomas Pouplin, Hao Sun, Samuel Holt +1

Large Language Models (LLMs) have demonstrated the strong potential to assist both clinicians and the general public with their extensive medical knowledge. However, their applicat…

cs.LG2024★ 2 cited

Dense Reward for Free in Reinforcement Learning from Human Feedback

Alex J. Chan, Hao Sun, Samuel Holt +1

Reinforcement Learning from Human Feedback (RLHF) has been credited as the key advance that has allowed Large Language Models (LLMs) to effectively follow instructions and produce…

cs.LG2023

When is Off-Policy Evaluation (Reward Modeling) Useful in Contextual Bandits? A Data-Centric Perspective

Hao Sun, Alex J. Chan, Nabeel Seedat +2

Evaluating the value of a hypothetical target policy with only a logged dataset is important but challenging. On the one hand, it brings opportunities for safe policy improvement u…

cs.LG2023

Accountability in Offline Reinforcement Learning: Explaining Decisions with a Corpus of Examples

Hao Sun, Alihan Hüyük, Daniel Jarrett +1

Learning controllers with offline data in decision-making systems is an essential area of research due to its potential to reduce the risk of applications in real-world systems. Ho…

cs.LG2023★ 1 cited

Reinforcement Learning in the Era of LLMs: What is Essential? What is needed? An RL Perspective on RLHF, Prompting, and Beyond

Hao Sun

Recent advancements in Large Language Models (LLMs) have garnered wide attention and led to successful products such as ChatGPT and GPT-4. Their proficiency in adhering to instruct…

cs.CL2023★ 4 cited

Query-Dependent Prompt Evaluation and Optimization with Offline Inverse RL

Hao Sun, Alihan Hüyük, Mihaela van der Schaar

In this study, we aim to enhance the arithmetic reasoning ability of Large Language Models (LLMs) through zero-shot prompt optimization. We identify a previously overlooked objecti…

cs.CL2023★ 11 cited

ChatHaruhi: Reviving Anime Character in Reality via Large Language Model

Cheng Li, Ziang Leng, Chenxi Yan +11

Role-playing chatbots built on large language models have drawn interest, but better techniques are needed to enable mimicking specific fictional characters. We propose an algorith…