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Hangfan Zhang

9 accepted papers

2026

Adaptive Code Watermarking Through Reinforcement Learning

ICML 2026poster

As LLMs increasingly generate production code, protecting intellectual property demands watermarking techniques that respect code's strict syntactic constraints. In this work, we introduce CodeTracer, an innovative adaptive code watermarking framework underpinned by a reinforcement learning training…

Cited by 0SourceScholar
2026

Can Simple Denoising Improve Uniform State Diffusion Models?

ICML 2026poster

Recent Uniform-state Diffusion Models (USDMs), initialized from a uniform prior, offer the promise of fast text generation due to their inherent self-correction ability compared to masked diffusion models. However, they still rely on complex loss formulations with additional computational overhead, …

Cited by 0SourceScholar
2026

Do We Truly Need So Many Samples? Multi-LLM Repeated Sampling Efficiently Scales Test-Time Compute

AAAI 2026technical

This paper presents a simple, effective, and cost-efficient strategy, named ModelSwitch, to improve LLM performance by scaling test-time compute. ModelSwitch builds upon the repeated-sampling-then-voting framework, with a novel twist: incorporating multiple models, even weaker ones, to leverage the

Cited by 0SourcePDFScholar
2025

Explainable Reinforcement Learning from Human Feedback to Improve Alignment

NeurIPS 2025poster

A common and effective strategy for humans to improve an unsatisfactory outcome in daily life is to find a cause of this outcome and correct the cause. In this paper, we investigate whether this human improvement strategy can be applied to improving reinforcement learning from human feedback (RLHF)…

Cited by 0SourceScholar
2025

Reinforcement Learning for Large Language Models via Group Preference Reward Shaping

EMNLP 2025

Large Language Models (LLMs) require alignment via reinforcement learning (RL) to effectively perform task-specific objectives, such as human preference alignment and enhanced reasoning. While Proximal Policy Optimization (PPO) is widely adopted, its computational overhead, stemming from additional

Cited by 0SourcePDFScholar
2025

Simple Distillation for One-Step Diffusion Models

NeurIPS 2025poster

Diffusion models have established themselves as leading techniques for image generation. However, their reliance on an iterative denoising process results in slow sampling speeds, which limits their applicability to interactive and creative applications. An approach to overcoming this limitation inv…

Cited by 0SourceScholar
2024

Jailbreak Open-Sourced Large Language Models via Enforced Decoding

ACL 2024long

Large Language Models (LLMs) have achieved unprecedented performance in Natural Language Generation (NLG) tasks. However, many existing studies have shown that they could be misused to generate undesired content. In response, before releasing LLMs for public access, model developers usually align th…

Cited by 14SourcePDFScholar
2023

A3FL: Adversarially Adaptive Backdoor Attacks to Federated Learning

NeurIPS 2023poster

Federated Learning (FL) is a distributed machine learning paradigm that allows multiple clients to train a global model collaboratively without sharing their local training data. Due to its distributed nature, many studies have shown that it is vulnerable to backdoor attacks. However, existing studi…