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Weiming Liu

46 accepted papers

2026

BAMFair: Barycenter Aligned Mediation for Fairness Across Multiple Sensitive Attributes

IJCAI 2026

Achieving fairness in machine learning models while maintaining high accuracy is an important but complex task, especially when handling multiple sensitive attributes. Traditional fairness methods often struggle to eliminate bias within subgroups divided by sensitive attributes. Several key challeng

Cited by 0Scholar
2026

Bypassing the Transport Plan: Dynamic Reweighting for Out-of-Distribution Detection with Optimal Transport

CVPR 2026

Semi-supervised learning (SSL) has achieved remarkable progress by leveraging both limited labeled data and abundant unlabeled data. However, unlabeled datasets often contain out-of-distribution (OOD) samples from unknown classes, which can lead to performance degradation in open-set SSL scenarios.

Cited by 0SourceScholar
2026

DeCo-DETR: Decoupled Cognition DETR for efficient Open-Vocabulary Object Detection

ICLR 2026poster

Open-Vocabulary Object Detection (OVOD) plays a critical role in autonomous driving and human-computer interaction by enabling perception beyond closed-set categories. However, current approaches predominantly rely on multimodal fusion, facing dual limitations: multimodal fusion methods incur heavy…

Cited by 0SourceScholar
2026

IdeFN: Identifying Unclicked Space False Negatives via Relaxed Partial Optimal Transport for Conversion Rate Prediction

AAAI 2026technical

Accurate conversion rate (CVR) prediction is critical for recommender systems to capture user conversion intent and increase platform revenues. Traditional CVR models commonly suffer from sample selection bias (SSB) and data sparsity (DS), which has led to the adoption of click-through & conversion

Cited by 0SourcePDFScholar
2026

Joint Multi-Modal Multi-Interest Profiling and Preference-Grounded Reasoning for Explainable Recommendation

IJCAI 2026

Explainable Recommendation (ER) aims to enhance recommendation transparency and prediction accuracy by providing faithful and persuasive explanations. However, Multi-Modal Multi-Interest Explainable Recommendation (MMER) is particularly challenging in two aspects: effectively utilizing diverse multi

Cited by 0Scholar
2026

Potent but Stealthy: Rethink Profile Pollution Against Sequential Recommendation via Bi-Level Constrained Reinforcement Paradigm

AAAI 2026technical

Sequential Recommenders, which exploit dynamic user intents through interaction sequences, are vulnerable to adversarial attacks. While existing attacks primarily rely on data poisoning, they require large-scale user access or fake profiles thus lacking practicality. In this paper, we focus on the P

Cited by 0SourcePDFScholar
2026

Preference-Calibrated Optimization with Score-Level Distribution Alignment for Text-to-Image Diffusion Model Unlearning

ICML 2026poster

While text-to-image diffusion models achieve remarkable generation quality, they inadvertently memorize sensitive content, necessitating machine unlearning to prevent undesired outputs. However, existing unlearning methods rely on suboptimal surrogate objectives rather than directly optimizing the u…

Cited by 0SourceScholar
2026

Spiked-CFR: Causal Representation Learning from LLMs via Wasserstein Projection Pursuit

ICML 2026poster

Estimating treatment effects from observational text is increasingly practical with Large Language Models (LLMs). However, applying causal representation learning directly to high-dimensional LLM embeddings faces a fundamental barrier: empirical Wasserstein matching suffers from the curse of dimensi…

Cited by 0SourceScholar
2026

Subspace-Aware Graph Construction and Contrastive Alignment for Multimodal Recommendation with Large Language Models

AAAI 2026technical

Multimedia content offers additional context for recommender systems to better understand user interests. Existing studies on multimodal recommendation primarily focus on constructing item-item semantic graphs. However, most of these methods capture only shallow semantic structures based on feature

Cited by 0SourcePDFScholar
2025

Balancing User-Item Structure and Interaction with Large Language Models and Optimal Transport for Multimedia Recommendation

IJCAI 2025

The rapid growth of multimedia content has driven the development of recommender systems. Most previous work focuses on uncovering latent relationships among items to learn better representations. However, this approach does not sufficiently account for user affinities, potentially leading to an imb

2025

DR-VAE: Debiased and Representation-enhanced Variational Autoencoder for Collaborative Recommendation

AAAI 2025technical

Recommender Systems (RSs) are widely applied for navigating information, and Collaborative Filtering (CF) is one of prominent recommendation techniques due to the advantages of domain independence and easy interpretation. Among the numerous CF methods, Variational Autoencoders (VAE), benefiting from…

2025

Deterministic-to-Stochastic Diverse Latent Feature Mapping for Human Motion Synthesis

CVPR 2025poster

Human motion synthesis aims to generate plausible human motion sequences, which has raised widespread attention in computer animation. Recent score-based generative models (SGMs) have demonstrated impressive results on this task. However, their training process involves complex curvature trajectorie…

Cited by 0SourcePDFScholar
2025

Distinguish Then Exploit: Source-free Open Set Domain Adaptation via Weight Barcode Estimation and Sparse Label Assignment

CVPR 2025poster

Nowadays, domain adaptation techniques have been widely investigated for knowledge sharing from labeled source domain to unlabeled target domain. However, target domain may include some data samples that belong to unknown categories in real-world scenarios. Moreover, the target domain cannot access…

Cited by 0SourcePDFScholar
2025

Diverse Policies Recovering via Pointwise Mutual Information Weighted Imitation Learning

ICLR 2025poster

Recovering a spectrum of diverse policies from a set of expert trajectories is an important research topic in imitation learning. After determining a latent style for a trajectory, previous diverse polices recovering methods usually employ a vanilla behavioral cloning learning objective conditioned…

Cited by 0SourcePDFScholar
2025

Efficient Source-free Unlearning via Energy-Guided Data Synthesis and Discrimination-Aware Multitask Optimization

ICML 2025spotlight

With growing privacy concerns and the enforcement of data protection regulations, machine unlearning has emerged as a promising approach for removing the influence of forget data while maintaining model performance on retain data. However, most existing unlearning methods require access to the origi…

Cited by 0SourcePDFScholar
2025

Enhancing Diffusion Model with Auxiliary Information Mining-Exploration and Efficient Sampling Mechanism for Sequential Recommendation

AAAI 2025technical

Sequential recommendation aims to capture the temporal dependencies of items in a user's historical interactions and make recommendations based on this. Previous generative methods addressed the issue of data not directly reflecting user preference uncertainty by modeling the distribution of latent…

Cited by 1SourcePDFScholar
2025

FOCoOp: Enhancing Out-of-Distribution Robustness in Federated Prompt Learning for Vision-Language Models

ICML 2025poster

Federated prompt learning (FPL) for vision-language models is a powerful approach to collaboratively adapt models across distributed clients while preserving data privacy. However, existing FPL approaches suffer from a trade-off between performance and robustness, particularly in out-of-distribution…

Cited by 0SourcePDFScholar
2025

FedGOG: Federated Graph Out-of-Distribution Generalization with Diffusion Data Exploration and Latent Embedding Decorrelation

AAAI 2025technical

Federated graph learning (FGL) has emerged as a promising approach to enable collaborative training of graph models while preserving data privacy. However, current FGL methods overlook the out-of-distribution (OOD) shifts that occur in real-world scenarios. The distribution shifts between training a…

Cited by 0SourcePDFScholar
2025

Improving Zero-Shot Adversarial Robustness in Vision-Language Models by Closed-form Alignment of Adversarial Path Simplices

ICML 2025spotlight

Vision-Language Models (VLMs) such as CLIP excel at zero-shot classification due to large-scale pre-training but are vulnerable to adversarial examples. Adversarial fine-tuning robustifies zero-shot models by aligning prediction scores of individual adversaries with their clean counterparts, which t…

Cited by 0SourcePDFScholar
2025

Robustifying Zero-Shot Vision Language Models by Subspaces Alignment

ICCV 2025poster

Vision-Language Models (VLMs) enjoy strong zero-shot performance but are vulnerable to adversarial attacks posing security risks. Adversarially robust fine-tuning enhances zero-shot robustness on new datasets while preserving the natural performance of pre-trained VLMs. However, prior methods use sa…

Cited by 0SourcePDFScholar
2025

Solving Discrete (Semi) Unbalanced Optimal Transport with Equivalent Transformation Mechanism and KKT-Multiplier Regularization

NeurIPS 2025poster

Semi-Unbalanced Optimal Transport (SemiUOT) shows great promise in matching two probability measures by relaxing one of the marginal constraints. Previous solvers often incorporate an entropy regularization term, which can result in inaccurate matching solutions. To address this issue, we focus on d…

Cited by 0SourceScholar
2025

Towards Provably Efficient Learning of Imperfect Information Extensive-Form Games with Linear Function Approximation

UAI 2025

Despite significant advances in learning imperfect information extensive-form games (IIEFGs), most existing theoretical guarantees are limited to IIEFGs in the tabular case. To permit efficient learning of large-scale IIEFGs, we take the first step in studying two-player zero-sum IIEFGs with linear

2025

Variational Graph Auto-Encoder Driven Graph Enhancement for Sequential Recommendation

IJCAI 2025

Recommender systems play a critical role in many applications by providing personalized recommendations based on user interactions. However, it remains a major challenge to capture complex sequential patterns and address noise in user interaction data. While advanced neural networks have enhanced se

Cited by 0SourcePDFScholar
2024

Counterfactual User Sequence Synthesis Augmented with Continuous Time Dynamic Preference Modeling for Sequential POI Recommendation

IJCAI 2024poster

With the proliferation of Location-based Social Networks (LBSNs), user check-in data at Points-of-Interest (POIs) has surged, offering rich insights into user preferences. However, sequential POI recommendation systems always face two pivotal challenges. A challenge lies in the difficulty of modelin…

Cited by 11SourcePDFScholar
2024

Enhancing Dual-Target Cross-Domain Recommendation with Federated Privacy-Preserving Learning

IJCAI 2024poster

Recently, dual-target cross-domain recommendation (DTCDR) has been proposed to alleviate the data sparsity problem by sharing the common knowledge across domains simultaneously. However, existing methods often assume that personal data containing abundant identifiable information can be directly acc…

Cited by 2SourcePDFScholar
2024

FOOGD: Federated Collaboration for Both Out-of-distribution Generalization and Detection

NeurIPS 2024poster

Federated learning (FL) is a promising machine learning paradigm that collaborates with client models to capture global knowledge. However, deploying FL models in real-world scenarios remains unreliable due to the coexistence of in-distribution data and unexpected out-of-distribution (OOD) data, suc…

2024

Intra- and Inter-group Optimal Transport for User-Oriented Fairness in Recommender Systems

AAAI 2024technical

Recommender systems are typically biased toward a small group of users, leading to severe unfairness in recommendation performance, i.e., User-Oriented Fairness (UOF) issue. Existing research on UOF exhibits notable limitations in two phases of recommendation models. In the training phase, current m…

Cited by 6SourcePDFScholar
2024

Learning Accurate and Bidirectional Transformation via Dynamic Embedding Transportation for Cross-Domain Recommendation

AAAI 2024technical

With the rapid development of Internet and Web techniques, Cross-Domain Recommendation (CDR) models have been widely explored for resolving the data-sparsity and cold-start problem. Meanwhile, most CDR models should utilize explicit domain-shareable information (e.g., overlapped users or items) for…

Cited by 24SourcePDFScholar
2024

Reducing Item Discrepancy via Differentially Private Robust Embedding Alignment for Privacy-Preserving Cross Domain Recommendation

ICML 2024poster

Cross-Domain Recommendation (CDR) have become increasingly appealing by leveraging useful information to tackle the data sparsity problem across domains. Most of latest CDR models assume that domain-shareable user-item information (e.g., rating and review on overlapped users or items) are accessible…

Cited by 7SourcePDFScholar
2024

Rethinking the Representation in Federated Unsupervised Learning with Non-IID Data

CVPR 2024poster

Federated learning achieves effective performance in modeling decentralized data. In practice client data are not well-labeled which makes it potential for federated unsupervised learning (FUSL) with non-IID data. However the performance of existing FUSL methods suffers from insufficient representat…

Cited by 17SourcePDFScholar
2024

TFGDA: Exploring Topology and Feature Alignment in Semi-supervised Graph Domain Adaptation through Robust Clustering

NeurIPS 2024poster

Semi-supervised graph domain adaptation, as a branch of graph transfer learning, aims to annotate unlabeled target graph nodes by utilizing transferable knowledge learned from a label-scarce source graph. However, most existing studies primarily concentrate on aligning feature distributions directly…

Cited by 3SourcePDFScholar
2023

Federated Probabilistic Preference Distribution Modelling with Compactness Co-Clustering for Privacy-Preserving Multi-Domain Recommendation

IJCAI 2023poster

With the development of modern internet techniques, Cross-Domain Recommendation (CDR) systems have been widely exploited for tackling the data-sparsity problem. Meanwhile most current CDR models assume that user-item interactions are accessible across different domains. However, such knowledge shari…

Cited by 35SourcePDFScholar
2023

HyperFed: Hyperbolic Prototypes Exploration with Consistent Aggregation for Non-IID Data in Federated Learning

IJCAI 2023poster

Federated learning (FL) collaboratively models user data in a decentralized way. However, in the real world, non-identical and independent data distributions (non-IID) among clients hinder the performance of FL due to three issues, i.e., (1) the class statistics shifting, (2) the insufficient hierar…

Cited by 18SourcePDFScholar
2023

Optimal Transport for Treatment Effect Estimation

NeurIPS 2023poster

Estimating individual treatment effects from observational data is challenging due to treatment selection bias. Prevalent methods mainly mitigate this issue by aligning different treatment groups in the latent space, the core of which is the calculation of distribution discrepancy. However, two issu…

Cited by 58SourcePDFScholar
2023

PPGenCDR: A Stable and Robust Framework for Privacy-Preserving Cross-Domain Recommendation

AAAI 2023technical

Privacy-preserving cross-domain recommendation (PPCDR) refers to preserving the privacy of users when transferring the knowledge from source domain to target domain for better performance, which is vital for the long-term development of recommender systems. Existing work on cross-domain recommendati…

Cited by 28SourcePDFScholar
2023

Policy Space Diversity for Non-Transitive Games

NeurIPS 2023poster

Policy-Space Response Oracles (PSRO) is an influential algorithm framework for approximating a Nash Equilibrium (NE) in multi-agent non-transitive games. Many previous studies have been trying to promote policy diversity in PSRO. A major weakness with existing diversity metrics is that a more divers…

Cited by 18SourcePDFScholar
2023

Robust Representation Learning with Reliable Pseudo-labels Generation via Self-Adaptive Optimal Transport for Short Text Clustering

ACL 2023long

Short text clustering is challenging since it takes imbalanced and noisy data as inputs. Existing approaches cannot solve this problem well, since (1) they are prone to obtain degenerate solutions especially on heavy imbalanced datasets, and (2) they are vulnerable to noises. To tackle the above iss…

2023

UltraRE: Enhancing RecEraser for Recommendation Unlearning via Error Decomposition

NeurIPS 2023poster

With growing concerns regarding privacy in machine learning models, regulations have committed to granting individuals the right to be forgotten while mandating companies to develop non-discriminatory machine learning systems, thereby fueling the study of the machine unlearning problem. Our attentio…

2023

WalkLM: A Uniform Language Model Fine-tuning Framework for Attributed Graph Embedding

NeurIPS 2023poster

Graphs are widely used to model interconnected entities and improve downstream predictions in various real-world applications. However, real-world graphs nowadays are often associated with complex attributes on multiple types of nodes and even links that are hard to model uniformly, while the widely…

2022

Actor-Critic Policy Optimization in a Large-Scale Imperfect-Information Game

ICLR 2022poster

The deep policy gradient method has demonstrated promising results in many large-scale games, where the agent learns purely from its own experience. Yet, policy gradient methods with self-play suffer convergence problems to a Nash Equilibrium (NE) in multi-agent situations. Counterfactual regret min…

Cited by 33SourcePDFScholar
2022

Equivalence Analysis between Counterfactual Regret Minimization and Online Mirror Descent

ICML 2022spotlight

Follow-the-Regularized-Leader (FTRL) and Online Mirror Descent (OMD) are regret minimization algorithms for Online Convex Optimization (OCO), they are mathematically elegant but less practical in solving Extensive-Form Games (EFGs). Counterfactual Regret Minimization (CFR) is a technique for approxi…

2022

Greedy when Sure and Conservative when Uncertain about the Opponents

ICML 2022spotlight

We develop a new approach, named Greedy when Sure and Conservative when Uncertain (GSCU), to competing online against unknown and nonstationary opponents. GSCU improves in four aspects: 1) introduces a novel way of learning opponent policy embeddings offline; 2) trains offline a single best response…

2022

HCFRec: Hash Collaborative Filtering via Normalized Flow with Structural Consensus for Efficient Recommendation

IJCAI 2022poster

The ever-increasing data scale of user-item interactions makes it challenging for an effective and efficient recommender system. Recently, hash-based collaborative filtering (Hash-CF) approaches employ efficient Hamming distance of learned binary representations of users and items to accelerate reco…

2021

Leveraging Distribution Alignment via Stein Path for Cross-Domain Cold-Start Recommendation

NeurIPS 2021poster

Cross-Domain Recommendation (CDR) has been popularly studied to utilize different domain knowledge to solve the cold-start problem in recommender systems. In this paper, we focus on the Cross-Domain Cold-Start Recommendation (CDCSR) problem. That is, how to leverage the information from a source dom…

Cited by 72SourcePDFScholar