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Yihua Zhang

36 accepted papers

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
2026

Safety Mirage: How Spurious Correlations Undermine VLM Safety Fine-Tuning and Can Be Mitigated by Machine Unlearning

ICLR 2026poster

Recent vision language models (VLMs) have made remarkable strides in generative modeling with multimodal inputs, particularly text and images. However, their susceptibility to generating harmful content when exposed to unsafe queries raises critical safety concerns. While current alignment strategie…

Cited by 0SourcecodeScholar
2025

Edit Away and My Face Will not Stay: Personal Biometric Defense against Malicious Generative Editing

CVPR 2025poster

Recent advancements in diffusion models have made generative image editing more accessible than ever. While these developments allow users to generate creative edits with ease, they also raise significant ethical concerns, particularly regarding malicious edits to human portraits that threaten indiv…

2025

Invariance Makes LLM Unlearning Resilient Even to Unanticipated Downstream Fine-Tuning

ICML 2025poster

Machine unlearning presents a promising approach to mitigating privacy and safety concerns in large language models (LLMs) by enabling the selective removal of targeted data or knowledge while preserving model utility. However, existing unlearning methods remain over-sensitive to downstream fine-tun…

2025

Invisible Watermarks, Visible Gains: Steering Machine Unlearning with Bi-Level Watermarking Design

ICCV 2025poster

With the increasing demand for the right to be forgotten, machine unlearning (MU) has emerged as a vital tool for enhancing trust and regulatory compliance by enabling the removal of sensitive data influences from machine learning (ML) models. However, most MU algorithms primarily rely on in-trainin…

Cited by 0SourcePDFScholar
2025

One Token Embedding Is Enough to Deadlock Your Large Reasoning Model

NeurIPS 2025poster

Modern large reasoning models (LRMs) exhibit impressive multi-step problem-solving via chain-of-thought (CoT) reasoning. However, this iterative thinking mechanism introduces a new vulnerability surface. We present the Deadlock Attack, a resource exhaustion method that hijacks an LRM's generative co…

Cited by 0SourceScholar
2025

Pruning then Reweighting: Towards Data-Efficient Training of Diffusion Models

ICASSP 2025accepted

Despite the remarkable generation capabilities of Diffusion Models (DMs), conducting training and inference remains computationally expensive. Previous works have been devoted to accelerating diffusion sampling, but achieving data-efficient diffusion training has often been overlooked. In this work,…

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

SEUF: Is Unlearning One Expert Enough for Mixture-of-Experts LLMs?

ACL 2025long

Recent advancements in LLMs unlearning have shown remarkable success in removing unwanted data-model influences while preserving the model’s utility for legitimate knowledge. Despite these strides, sparse Mixture-of-Experts (MoE) LLMs–a key subset of the LLM family–have remained unexplored in the co…

Cited by 0SourcePDFScholar
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…

2025

Visual Prompting Upgrades Neural Network Sparsification: A Data-Model Perspective

AAAI 2025technical

The rapid development of large-scale deep learning models questions the affordability of hardware platforms, which necessitates the pruning to reduce their computational and memory footprints. Sparse neural networks as the product, have demonstrated numerous favorable benefits like low complexity, u…

2025

When is Task Vector Provably Effective for Model Editing? A Generalization Analysis of Nonlinear Transformers

ICLR 2025oral

Task arithmetic refers to editing the pre-trained model by adding a weighted sum of task vectors, each of which is the weight update from the pre-trained model to fine-tuned models for certain tasks. This approach recently gained attention as a computationally efficient inference method for model ed…

Cited by 0SourcePDFScholar
2024

DeepZero: Scaling Up Zeroth-Order Optimization for Deep Model Training

ICLR 2024poster

Zeroth-order (ZO) optimization has become a popular technique for solving machine learning (ML) problems when first-order (FO) information is difficult or impossible to obtain. However, the scalability of ZO optimization remains an open problem: Its use has primarily been limited to relatively small…

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

Revisiting Zeroth-Order Optimization for Memory-Efficient LLM Fine-Tuning: A Benchmark

ICML 2024poster

In the evolving landscape of natural language processing (NLP), fine-tuning pre-trained Large Language Models (LLMs) with first-order (FO) optimizers like SGD and Adam has become standard. Yet, as LLMs grow in size, the substantial memory overhead from back-propagation (BP) for FO gradient computati…

2024

SOUL: Unlocking the Power of Second-Order Optimization for LLM Unlearning

EMNLP 2024main

Large Language Models (LLMs) have highlighted the necessity of effective unlearning mechanisms to comply with data regulations and ethical AI practices. LLM unlearning aims at removing undesired data influences and associated model capabilities without compromising utility beyond the scope of unlear…

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

The Power of Few: Accelerating and Enhancing Data Reweighting with Coreset Selection

ICASSP 2024accepted

As machine learning tasks continue to evolve, the trend has been to gather larger datasets and train increasingly larger models. While this has led to advancements in accuracy, it has also escalated computational costs to unsustainable levels. Addressing this, our work aims to strike a delicate bala…

Cited by 0SourceScholar
2024

To Generate or Not? Safety-Driven Unlearned Diffusion Models Are Still Easy To Generate Unsafe Images ... For Now

ECCV 2024poster

"The recent advances in diffusion models (DMs) have revolutionized the generation of realistic and complex images. However, these models also introduce potential safety hazards, such as producing harmful content and infringing data copyrights. Despite the development of safety-driven unlearning tech…

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…

2024

WAGLE: Strategic Weight Attribution for Effective and Modular Unlearning in Large Language Models

NeurIPS 2024poster

The need for effective unlearning mechanisms in large language models (LLMs) is increasingly urgent, driven by the necessity to adhere to data regulations and foster ethical generative AI practices. LLM unlearning is designed to reduce the impact of undesirable data influences and associated model c…

2023

Linearly Constrained Bilevel Optimization: A Smoothed Implicit Gradient Approach

ICML 2023poster

This work develops analysis and algorithms for solving a class of bilevel optimization problems where the lower-level (LL) problems have linear constraints. Most of the existing approaches for constrained bilevel problems rely on value function-based approximate reformulations, which suffer from iss…

Cited by 22SourcePDFScholar
2023

Robust Mixture-of-Expert Training for Convolutional Neural Networks

ICCV 2023oral

Sparsely-gated Mixture of Expert (MoE), an emerging deep model architecture, has demonstrated a great promise to enable high-accuracy and ultra-efficient model inference. Despite the growing popularity of MoE, little work investigated its potential to advance convolutional neural networks (CNNs), es…

Cited by 47PDFcodeScholar
2023

Robustness-Preserving Lifelong Learning Via Dataset Condensation

ICASSP 2023accepted

Lifelong learning (LL) aims to improve a predictive model as the data source evolves continuously. Most work in this learning paradigm has focused on resolving the problem of ‘catastrophic forgetting,’ which refers to a notorious dilemma between improving model accuracy over new data and retaining a…

Cited by 5SourceScholar
2023

Selectivity Drives Productivity: Efficient Dataset Pruning for Enhanced Transfer Learning

NeurIPS 2023poster

Massive data is often considered essential for deep learning applications, but it also incurs significant computational and infrastructural costs. Therefore, dataset pruning (DP) has emerged as an effective way to improve data efficiency by identifying and removing redundant training samples without…

2023

TextGrad: Advancing Robustness Evaluation in NLP by Gradient-Driven Optimization

ICLR 2023poster

Robustness evaluation against adversarial examples has become increasingly important to unveil the trustworthiness of the prevailing deep models in natural language processing (NLP). However, in contrast to the computer vision domain where the first-order projected gradient descent (PGD) is used as…

2023

Understanding and Improving Visual Prompting: A Label-Mapping Perspective

CVPR 2023poster

We revisit and advance visual prompting (VP), an input prompting technique for vision tasks. VP can reprogram a fixed, pre-trained source model to accomplish downstream tasks in the target domain by simply incorporating universal prompts (in terms of input perturbation patterns) into downstream data…

2023

What Is Missing in IRM Training and Evaluation? Challenges and Solutions

ICLR 2023poster

Invariant risk minimization (IRM) has received increasing attention as a way to acquire environment-agnostic data representations and predictions, and also a principled solution for preventing spurious correlations from being learned and improving models’ out-of-distribution generalization. Yet, rec…

Cited by 8SourcePDFScholar
2022

Advancing Model Pruning via Bi-level Optimization

NeurIPS 2022accept

The deployment constraints in practical applications necessitate the pruning of large-scale deep learning models, i.e., promoting their weight sparsity. As illustrated by the Lottery Ticket Hypothesis (LTH), pruning also has the potential of improving their generalization ability. At the core of LTH…

2022

Distributed adversarial training to robustify deep neural networks at scale

UAI 2022poster

Current deep neural networks (DNNs) are vulnerable to adversarial attacks, where adversarial perturbations to the inputs can change or manipulate classification. To defend against such attacks, an effective and popular approach, known as adversarial training (AT), has been shown to mitigate the nega…

2022

Quarantine: Sparsity Can Uncover the Trojan Attack Trigger for Free

CVPR 2022poster

Trojan attacks threaten deep neural networks (DNNs) by poisoning them to behave normally on most samples, yet to produce manipulated results for inputs attached with a particular trigger. Several works attempt to detect whether a given DNN has been injected with a specific trigger during the trainin…

Cited by 29PDFcodeScholar
2022

Revisiting and Advancing Fast Adversarial Training Through The Lens of Bi-Level Optimization

ICML 2022spotlight

Adversarial training (AT) is a widely recognized defense mechanism to gain the robustness of deep neural networks against adversarial attacks. It is built on min-max optimization (MMO), where the minimizer (i.e., defender) seeks a robust model to minimize the worst-case training loss in the presence…