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Xiaoxiao Li

50 accepted papers

2026

Cross-View Lewis Weight Fusion Empowering Exemplar Replay for Federated Class-Incremental Learning

ICML 2026poster

Federated Class-Incremental Learning (FCIL) aims to continually expand a model’s recognition capacity in a distributed environment, enabling it to learn new classes while retaining knowledge of previously seen ones. Exemplar replay has emerged as a promising strategy owing to its simplicity and effe…

Cited by 0SourceScholar
2026

FedRE: A Representation Entanglement Framework for Model-Heterogeneous Federated Learning

CVPR 2026

Federated learning (FL) enables collaborative training across clients while preserving privacy. While most existing FL methods assume homogeneous model architectures, client heterogeneity in both data and resources makes this assumption impractical, thus motivating model-heterogeneous FL. To address

Cited by 0SourcecodeScholar
2026

On Group Relative Policy Optimization Collapse in Agent Search: The Lazy Likelihood-Displacement

ICML 2026poster

Tool-integrated (TI) reinforcement learning (RL) enables large language models (LLMs) to perform multi-step reasoning by interacting with external tools such as search engines and retrievers. Group Relative Policy Optimization (GRPO), exemplified by the recent Search-R1, offers fast convergence and …

Cited by 0SourceScholar
2026

TextResNet: Decoupling and Routing Optimization Signals in Compound AI Systems via Deep Residual Tuning

ICML 2026poster

Textual Gradient-style optimizers (TextGrad) enable gradient-like feedback propagation through compound AI systems. However, they do not work well for deep chains. The root cause of this limitation stems from the *Semantic Entanglement* problem in these extended workflows. In standard textual backpr…

Cited by 0SourceScholar
2026

Token Hidden Reward: Steering Exploration-Exploitation in Group Relative Deep Reinforcement Learning

ICLR 2026poster

Reinforcement learning with verifiable rewards has significantly advanced the reasoning capabilities of large language models, yet how to explicitly steer training toward exploration or exploitation remains an open problem. We introduce Token Hidden Reward (THR), a token-level metric that quantifies…

Cited by 0SourceScholar
2026

TreeBridge: Aligning LLM Embeddings in Industrial Recommender Systems

AAAI 2026technical

Large language models (LLMs) have shown great potential in enhancing search and recommender systems by providing rich semantic representations from unstructured texts. However, directly integrating LLM embeddings into industrial recommendation pipelines often results in subpar performance due to the

Cited by 0SourcePDFScholar
2026

When RAG Hurts: Diagnosing and Mitigating Attention Distraction in Retrieval-Augmented LVLMs

ICML 2026poster

While Retrieval-Augmented Generation (RAG) is one of the dominant paradigms for enhancing Large Vision-Language Models (LVLMs) on knowledge-based VQA tasks, recent work attributes RAG failures to insufficient attention towards the retrieved context, proposing to reduce the attention allocated to ima…

Cited by 0SourceScholar
2025

A Reinforcement Learning-based Bidding Strategy for Data Consumers in Auction-based Federated Learning

NeurIPS 2025poster

Auction-based Federated Learning (AFL) fosters collaboration among self-interested data consumers (DCs) and data owners (DOs). A major challenge in AFL pertains to how DCs select and bid for DOs. Existing methods are generally static, making them ill-suited for dynamic AFL markets. To address this i…

Cited by 0SourceScholar
2025

Can Textual Gradient Work in Federated Learning?

ICLR 2025poster

Recent studies highlight the promise of LLM-based prompt optimization, especially with TextGrad, which automates ``differentiation'' via texts and backpropagates textual feedback provided by LLMs. This approach facilitates training in various real-world applications that do not support numerical gra…

2025

Class-wise Balancing Data Replay for Federated Class-Incremental Learning

NeurIPS 2025oral

Federated Class Incremental Learning (FCIL) aims to collaboratively process continuously increasing incoming tasks across multiple clients. Among various approaches, data replay has become a promising solution, which can alleviate forgetting by reintroducing representative samples from previous task…

Cited by 0SourceScholar
2025

DARE the Extreme: Revisiting Delta-Parameter Pruning For Fine-Tuned Models

ICLR 2025spotlight

Storing open-source fine-tuned models separately introduces redundancy and increases response times in applications utilizing multiple models. Delta-parameter pruning (DPP), particularly the random drop and rescale (DARE) method proposed by Yu et al., addresses this by pruning the majority of delta…

2025

GMValuator: Similarity-based Data Valuation for Generative Models

ICLR 2025poster

Data valuation plays a crucial role in machine learning. Existing data valuation methods, mainly focused on discriminative models, overlook generative models that have gained attention recently. In generative models, data valuation measures the impact of training data on generated datasets. Very few…

2025

Global Prompt Refinement with Non-Interfering Attention Masking for One-Shot Federated Learning

NeurIPS 2025poster

Federated Prompt Learning (FPL) enables communication-efficient adaptation by tuning lightweight prompts on top of frozen pre-trained models. Existing FPL methods typically rely on global information, which is only available after the second training round, to facilitate collaboration among client m…

Cited by 0SourceScholar
2025

Multi-Session Budget Optimization for Forward Auction-based Federated Learning

ICML 2025poster

Auction-based Federated Learning (AFL) has emerged as an important research field in recent years. The prevailing strategies for FL data consumers (DCs) assume that the entire team of the required data owners (DOs) for an FL task must be assembled before training can commence. In practice, a DC can…

Cited by 6SourcePDFScholar
2025

On the Effect of Negative Gradient in Group Relative Deep Reinforcement Optimization

NeurIPS 2025poster

Reinforcement learning (RL) has become popular in enhancing the reasoning capabilities of large language models (LLMs), with Group Relative Policy Optimization (GRPO) emerging as a widely used algorithm in recent systems. Despite GRPO's widespread adoption, we identify a previously unrecognized phen…

Cited by 0SourceScholar
2025

S4M: S4 for multivariate time series forecasting with Missing values

ICLR 2025poster

Multivariate time series data play a pivotal role in a wide range of real-world applications, such as finance, healthcare, and meteorology, where accurate forecasting is critical for informed decision-making and proactive interventions. However, the presence of block missing data introduces signific…

2025

pFedES: Generalized Proxy Feature Extractor Sharing for Model Heterogeneous Personalized Federated Learning

AAAI 2025technical

Federated learning (FL), as a privacy-preserving collaborative machine learning paradigm, has attracted significant interest from industry and academia. To allow each data owner (FL client) to train a heterogeneous and personalized local model based on its local data distribution, system resources a…

2024

A Bias-Free Revenue-Maximizing Bidding Strategy for Data Consumers in Auction-based Federated Learning

IJCAI 2024poster

Auction-based Federated Learning (AFL) is a burgeoning research area. However, existing bidding strategies for AFL data consumers (DCs) primarily focus on maximizing expected accumulated utility, disregarding the more complex goal of revenue maximization. They also only consider winning bids, leadin…

Cited by 7SourcePDFScholar
2024

Dual Calibration-based Personalised Federated Learning

IJCAI 2024poster

Personalized federated learning (PFL) is designed for scenarios with non-independent and identically distributed (non-IID) client data. Existing model mixup-based methods, one of the main approaches of PFL, can only extract either global or personalized features during training, thereby limiting eff…

Cited by 4SourcePDFScholar
2024

FairMedFM: Fairness Benchmarking for Medical Imaging Foundation Models

NeurIPS 2024poster

The advent of foundation models (FMs) in healthcare offers unprecedented opportunities to enhance medical diagnostics through automated classification and segmentation tasks. However, these models also raise significant concerns about their fairness, especially when applied to diverse and underrepre…

2024

FedCal: Achieving Local and Global Calibration in Federated Learning via Aggregated Parameterized Scaler

ICML 2024poster

Federated learning (FL) enables collaborative machine learning across distributed data owners, but data heterogeneity poses a challenge for model calibration. While prior work focused on improving accuracy for non-iid data, calibration remains under-explored. This study reveals existing FL aggregati…

Cited by 5SourcePDFScholar
2024

FedSSA: Semantic Similarity-based Aggregation for Efficient Model-Heterogeneous Personalized Federated Learning

IJCAI 2024poster

Federated learning (FL) is a privacy-preserving collaboratively machine learning paradigm. Traditional FL requires all data owners (a.k.a. FL clients) to train the same local model. This design is not well-suited for scenarios involving data and/or system heterogeneity. Model-Heterogeneous Personali…

2024

Federated Model Heterogeneous Matryoshka Representation Learning

NeurIPS 2024poster

Model heterogeneous federated learning (MHeteroFL) enables FL clients to collaboratively train models with heterogeneous structures in a distributed fashion. However, existing MHeteroFL methods rely on training loss to transfer knowledge between the client model and the server model, resulting in li…

Cited by 6SourcePDFScholar
2024

Heterogeneous Personalized Federated Learning by Local-Global Updates Mixing via Convergence Rate

ICLR 2024poster

Personalized federated learning (PFL) has emerged as a promising technique for addressing the challenge of data heterogeneity. While recent studies have made notable progress in mitigating heterogeneity associated with label distributions, the issue of effectively handling feature heterogeneity rema…

2024

Learning High-Order Relationships of Brain Regions

ICML 2024poster

Discovering reliable and informative relationships among brain regions from functional magnetic resonance imaging (fMRI) signals is essential in phenotypic predictions in neuroscience. Most of the current methods fail to accurately characterize those interactions because they only focus on pairwise…

2024

Local Superior Soups: A Catalyst for Model Merging in Cross-Silo Federated Learning

NeurIPS 2024poster

Federated learning (FL) is a learning paradigm that enables collaborative training of models using decentralized data. Recently, the utilization of pre-trained weight initialization in FL has been demonstrated to effectively improve model performance. However, the evolving complexity of current pr…

2024

Overcoming Data and Model heterogeneities in Decentralized Federated Learning via Synthetic Anchors

ICML 2024poster

Conventional Federated Learning (FL) involves collaborative training of a global model while maintaining user data privacy. One of its branches, decentralized FL, is a serverless network that allows clients to own and optimize different local models separately, which results in saving management and…

2024

Sample Quality Heterogeneity-aware Federated Causal Discovery through Adaptive Variable Space Selection

IJCAI 2024poster

Federated causal discovery (FCD) aims to uncover causal relationships among variables from decentralized data across multiple clients, while preserving data privacy. In practice, the sample quality of each client's local data may vary across different variable spaces, referred to as sample quality h…

2024

Unlocking the Potential of Prompt-Tuning in Bridging Generalized and Personalized Federated Learning

CVPR 2024poster

Vision Transformers (ViT) and Visual Prompt Tuning (VPT) achieve state-of-the-art performance with improved efficiency in various computer vision tasks. This suggests a promising paradigm shift of adapting pre-trained ViT models to Federated Learning (FL) settings. However the challenge of data hete…

Cited by 10SourcePDFScholar
2023

PerFedMask: Personalized Federated Learning with Optimized Masking Vectors

ICLR 2023poster

Recently, various personalized federated learning (FL) algorithms have been proposed to tackle data heterogeneity. To mitigate device heterogeneity, a common approach is to use masking. In this paper, we first show that using random masking can lead to a bias in the obtained solution of the learnin…

2022

Exploring Resolution and Degradation Clues As Self-Supervised Signal for Low Quality Object Detection

ECCV 2022poster

"Image restoration algorithms such as super resolution (SR) are indispensable pre-processing modules for object detection in low qual-ity images. Most of these algorithms assume the degradation is fixed andknown a priori. However, in pratical, either the real degrdation or optimalup-sampling ratio r…

2022

Federated Learning from Only Unlabeled Data with Class-conditional-sharing Clients

ICLR 2022poster

Supervised federated learning (FL) enables multiple clients to share the trained model without sharing their labeled data. However, potential clients might even be reluctant to label their own data, which could limit the applicability of FL in practice. In this paper, we show the possibility of unsu…

2021

FL-NTK: A Neural Tangent Kernel-based Framework for Federated Learning Analysis

ICML 2021spotlight

Federated Learning (FL) is an emerging learning scheme that allows different distributed clients to train deep neural networks together without data sharing. Neural networks have become popular due to their unprecedented success. To the best of our knowledge, the theoretical guarantees of FL concern…

Cited by 77SourcePDFScholar
2021

FedBN: Federated Learning on Non-IID Features via Local Batch Normalization

ICLR 2021poster

The emerging paradigm of federated learning (FL) strives to enable collaborative training of deep models on the network edge without centrally aggregating raw data and hence improving data privacy. In most cases, the assumption of independent and identically distributed samples across local clients…

2021

Subgraph Federated Learning with Missing Neighbor Generation

NeurIPS 2021spotlight

Graphs have been widely used in data mining and machine learning due to their unique representation of real-world objects and their interactions. As graphs are getting bigger and bigger nowadays, it is common to see their subgraphs separately collected and stored in multiple local systems. Therefore…

2020

Adaptive Checkpoint Adjoint Method for Gradient Estimation in Neural ODE

ICML 2020poster

The empirical performance of neural ordinary differential equations (NODEs) is significantly inferior to discrete-layer models on benchmark tasks (e.g. image classification). We demonstrate an explanation is the inaccuracy of existing gradient estimation methods: the adjoint method has numerical err…

2019

Hybrid Task Cascade for Instance Segmentation

CVPR 2019poster

Cascade is a classic yet powerful architecture that has boosted performance on various tasks. However, how to introduce cascade to instance segmentation remains an open question. A simple combination of Cascade R-CNN and Mask R-CNN only brings limited gain. In exploring a more effective approach, we…

Cited by 1727PDFcodeScholar
2018

Video Object Segmentation with Joint Re-identification and Attention-Aware Mask Propagation

ECCV 2018poster

The problem of video object segmentation can become extremely challenging when multiple instances co-exist. While each instance may exhibit large scale and pose variations, the problem is compounded when instances occlude each other causing failures in tracking. In this study, we formulate a deep re…

Cited by 257SourcePDFScholar
2017

Not All Pixels Are Equal: Difficulty-Aware Semantic Segmentation via Deep Layer Cascade

CVPR 2017spotlight

We propose a novel deep layer cascade (LC) method to improve the accuracy and speed of semantic segmentation. Unlike the conventional model cascade (MC) that is composed of multiple independent models, LC treats a single deep model as a cascade of several sub-models. Earlier sub-models are trained t…

Cited by 353PDFScholar