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Chongyu Fan

12 accepted papers

2026

Continual Unlearning for Text-to-Image Diffusion Models: A Regularization Perspective

ICLR 2026poster

Machine unlearning—the ability to remove designated concepts from a pre-trained model—has advanced rapidly, particularly for text-to-image diffusion models. However, existing methods typically assume that unlearning requests arrive all at once, whereas in practice they often arrive sequentially. We…

Cited by 0SourceScholar
2026

CyclicReflex: Improving Reasoning Models via Cyclical Reflection Token Scheduling

ICLR 2026poster

Large reasoning models (LRMs), such as OpenAI's o1 and DeepSeek-R1, harness test-time scaling to perform multi-step reasoning for complex problem-solving. This reasoning process, executed before producing final answers, is often guided by special juncture tokens that prompt self-evaluative reflectio…

Cited by 0SourcecodeScholar
2026

Downgrade to Upgrade: Optimizer Simplification Enhances Robustness in LLM Unlearning

ICLR 2026poster

Large language model (LLM) unlearning aims to surgically remove the influence of undesired data or knowledge from an existing model while preserving its utility on unrelated tasks. This paradigm has shown promise in addressing privacy and safety concerns. However, recent findings reveal that unlearn…

Cited by 0SourcecodeScholar
2026

Position: Zeroth-Order Optimization in Deep Learning Is Underexplored, Not Underpowered

ICML 2026spotlight

Zeroth-order (ZO) optimization, learning from finite differences of function evaluations without backpropagation, has recently regained attention in deep learning due to its memory efficiency and applicability to gray- or black-box pipelines. Yet, ZO methods are often dismissed as fundamentally unsc…

Cited by 0SourceScholar
2025

Reasoning Model Unlearning: Forgetting Traces, Not Just Answers, While Preserving Reasoning Skills

EMNLP 2025

Recent advances in large reasoning models (LRMs) have enabled strong multi-step reasoning capabilities. However, existing machine unlearning algorithms are tailored to standard language modeling and fail to address the unique challenges posed by LRMs. In this work, we present the first systematic st

Cited by 0SourcePDFScholar
2025

Simplicity Prevails: Rethinking Negative Preference Optimization for LLM Unlearning

NeurIPS 2025poster

This work studies the problem of large language model (LLM) unlearning, aiming to remove unwanted data influences (e.g., copyrighted or harmful content) while preserving model utility. Despite the increasing demand for unlearning, a technically-grounded optimization framework is lacking. Gradient as…

Cited by 0SourcecodeScholar
2025

The Fragile Truth of Saliency: Improving LLM Input Attribution via Attention Bias Optimization

NeurIPS 2025spotlight

Input saliency aims to quantify the influence of input tokens on the output of large language models (LLMs), which has been widely used for prompt engineering, model interpretability, and behavior attribution. Despite the proliferation of saliency techniques, the field lacks a standardized and rigor…

Cited by 0SourceScholar
2025

Towards LLM Unlearning Resilient to Relearning Attacks: A Sharpness-Aware Minimization Perspective and Beyond

ICML 2025poster

The LLM unlearning technique has recently been introduced to comply with data regulations and address the safety and ethical concerns of LLMs by removing the undesired data-model influence. However, state-of-the-art unlearning methods face a critical vulnerability: they are susceptible to ``relearn…

2024

Challenging Forgets: Unveiling the Worst-Case Forget Sets in Machine Unlearning

ECCV 2024poster

"The trustworthy machine learning (ML) community is increasingly recognizing the crucial need for models capable of selectively ‘unlearning’ data points after training. This leads to the problem of machine unlearning (), aiming to eliminate the influence of chosen data points on model performance, w…

2024

Defensive Unlearning with Adversarial Training for Robust Concept Erasure in Diffusion Models

NeurIPS 2024poster

Diffusion models (DMs) have achieved remarkable success in text-to-image generation, but they also pose safety risks, such as the potential generation of harmful content and copyright violations. The techniques of machine unlearning, also known as concept erasing, have been developed to address thes…

2024

SalUn: Empowering Machine Unlearning via Gradient-based Weight Saliency in Both Image Classification and Generation

ICLR 2024spotlight

With evolving data regulations, machine unlearning (MU) has become an important tool for fostering trust and safety in today's AI models. However, existing MU methods focusing on data and/or weight perspectives often suffer limitations in unlearning accuracy, stability, and cross-domain applicabilit…

2024

UnlearnCanvas: Stylized Image Dataset for Enhanced Machine Unlearning Evaluation in Diffusion Models

NeurIPS 2024poster

The technological advancements in diffusion models (DMs) have demonstrated unprecedented capabilities in text-to-image generation and are widely used in diverse applications. However, they have also raised significant societal concerns, such as the generation of harmful content and copyright dispute…