OpenRaiser/Intern-Atlas huggingface dataset:
SDE: A Simplified and Disentangled Dependency Encoding Framework for State Space Models in Time Series Forecasting
Authors: Zixuan Weng, Jindong Han, Wenzhao Jiang, Hao Liu
Venue: KDD
Year: 2025

In recent years, advancements in deep learning have spurred the development of numerous models for Long-term Time Series Forecasting (LTSF). However, most existing approaches struggle to fully capture the complex and structured dependencies inherent in time series data. In this work, we identify and formally define three critical dependencies that are fundamental to forecasting accuracy: order dependency and semantic dependency along the temporal dimension, as well as cross-variate dependency across the feature dimension. These dependencies are often treated in isolation, and improper handling can introduce noise and degrade forecasting performance. To bridge this gap, we investigate the potential of State Space Models (SSMs) for LTSF and emphasize their inherent advantages in capturing these essential dependencies. Additionally, we empirically observe that excessive nonlinearity in conventional SSMs introduce redundancy when applied to semantically sparse time series data. Motivated by this insight, we propose SDE (Simplified and Disentangled Dependency Encoding), a novel framework designed to enhance the capability of SSMs for LTSF. Specifically, we first eliminate unnecessary nonlinearities in vanilla SSMs, thereby improving the suitability for time series forecasting. Building on this foundation, we introduce a disentangled encoding strategy, which empowers SSMs to efficiently model cross-variate dependencies while mitigating interference between the temporal and feature dimensions. Furthermore, we provide rigorous theoretical justifications to substantiate our design choices. Extensive experiments on nine real-world benchmark datasets demonstrate that SDE-enhanced SSMs consistently outperform state-of-the-art time series forecasting models. Our code is available at https://github.com/YukinoAsuna/SAMBA.
Feature Selection for Network Intrusion Detection
Authors: Charles Westphal, Stephen Hailes, Mirco Musolesi
Venue: KDD
Year: 2025

Network Intrusion Detection (NID) remains a key area of research within the information security community, while also being relevant to Machine Learning (ML) practitioners. The latter generally aim to detect attacks using network features, which have been extracted from raw network data typically using dimensionality reduction methods, such as principal component analysis (PCA). However, PCA is not able to assess the relevance of features for the task at hand. Consequently, the features available are of varying quality, with some being entirely non-informative. From this, two major drawbacks arise. Firstly, trained and deployed models have to process large amounts of unnecessary data, therefore draining potentially costly resources. Secondly, the noise caused by the presence of irrelevant features can, in some cases, impede a model's ability to detect an attack. In order to deal with these challenges, we present Feature Selection for Network Intrusion Detection (FSNID) a novel information-theoretic method that facilitates the exclusion of non-informative features when detecting network intrusions. The proposed method is based on function approximation using a neural network, which enables a version of our approach that incorporates a recurrent layer. Consequently, this version uniquely enables the integration of temporal dependencies. Through an extensive set of experiments, we demonstrate that the proposed method selects a significantly reduced feature set, while maintaining NID performance. Code available at https://github.com/c-s-westphal/FSNID.
Local Homophily-Aware Graph Neural Network with Adaptive Polynomial Filters for Scalable Graph Anomaly Detection
Authors: Zengyi Wo, Minglai Shao, Shiyu Zhang, Ruijie Wang
Venue: KDD
Year: 2025

This paper presents the Local Homophily Graph Neural Network (LH-GNN), a novel framework for Graph Anomaly Detection (GAD). Anomalous activities in graphs often exhibit a complex interplay of homophily and heterophily, with our analysis revealing that anomalous nodes typically display a higher degree of heterophily compared to normal nodes. Existing GNN-based methods start to incorporate heterophily modeling but fail to address two critical challenges: (1) the efficiency challenge, as traditional spectral decomposition based methods are computationally expensive, and (2) the local homophily estimation challenge, where prior knowledge of node-wise homophily ratios is often unavailable. To address these challenges, LH-GNN introduces a lightweight polynomial graph filter that dynamically adjusts to node-specific homophily ratios, enabling efficient representation learning for both normal and anomalous nodes through adaptable heterophilic and homophilic bases. This design achieves linear time complexity, significantly improving computational efficiency. Additionally, we propose an iterative prototype learning strategy to estimate local homophily values without requiring additional labels. This strategy leverages class prototypes and uncertainty measures to assign reliable pseudo-labels, effectively capturing node-wise homophily. Together, these innovations enable LH-GNN to overcome the limitations of existing methods. Extensive experiments on four benchmark datasets demonstrate that LH-GNN outperforms state-of-the-art methods in both effectiveness and efficiency, achieving 4.4% improvements in detection accuracy and 11× computational speedup.
SepDiff: Self-Encoding Parameter Diffusion for Learning Latent Semantics
Authors: Zhangkai Wu, Xuhui Fan, Jin Li, Zhilin Zhao, Hui Chen, Longbing Cao
Venue: KDD
Year: 2025

The recently proposed Bayesian Flow Networks (BFNs) show great potential in modeling parameter spaces via a diffusion process, offering a unified strategy for handling continuous, discrete data. However, these parameter diffusion models cannot learn high-level semantic representation from the parameter space since common encoders, which encode data into one static representation, can- not capture semantic changes in parameters. This motivates a new direction: learning semantic representations hidden in the param- eter spaces to characterize noisy data. Accordingly, we propose a representation learning framework named SepDiff which operates in the parameter space to obtain parameter-wise latent semantics that exhibit progressive structures. Specifically, SepDiff proposes a self-encoder to learn latent semantics directly from parameters, rather than from observations. The encoder is then integrated into parameter diffusion model, enabling representation learning with various formats of observations. Mutual information terms further promote the disentanglement of latent semantics and capture mean- ingful semantics simultaneously. We illustrate seven representation learning tasks in SepDiff via expanding this parameter diffusion model, and extensive quantitative experimental results demonstrate the superior effectiveness of SepDiff in learning parameter repre- sentation.
Breaking the Memory Wall for Heterogeneous Federated Learning via Progressive Training
Authors: Yebo Wu, Li Li, Cheng-Zhong Xu
Venue: KDD
Year: 2025

Federated Learning (FL) enables multiple devices to collaboratively train a shared model while preserving data privacy. Most existing research assumes that all participating devices have sufficient resources to support the training process. However, the high memory requirements of model training present a significant challenge to deploying FL on resource-constrained devices in practical scenarios. To this end, this paper presents ProFL, a new framework that effectively addresses the memory constraints in FL. Rather than updating the full model during local training, ProFL partitions the model into blocks based on its original architecture and trains each block in a progressive fashion. It first trains the front blocks and safely freezes them after convergence. Training of the next block is then triggered. This process progressively grows the model to be trained until the training of the full model is completed. In this way, the peak memory footprint is effectively reduced for feasible deployment on heterogeneous devices. In order to preserve the feature representation of each block, the training process is divided into two stages: model shrinking and model growing. During the model shrinking stage, we meticulously design corresponding output modules to assist each block in learning the expected feature representation and obtain the initialization model parameters. Subsequently, the obtained output modules and initialization model parameters are utilized in the corresponding model growing stage, which progressively trains the full model. Additionally, a novel metric from the scalar perspective is proposed to assess the learning status of each block, enabling us to securely freeze it after convergence and initiate the training of the next one. Finally, we theoretically prove the convergence of ProFL and conduct extensive experiments on representative models and datasets to evaluate its effectiveness. The results demonstrate that ProFL effectively reduces the peak memory footprint by up to 57.4% and improves model accuracy by up to 82.4%.
ProgDiffusion: Progressively Self-encoding Diffusion Models
Authors: Zhangkai Wu, Xuhui Fan, Longbing Cao
Venue: KDD
Year: 2025

Learning low-dimensional semantic representations in diffusion models (DMs) is an open task, since in standard DMs, the dimensions of its intermediate latents are the same as that of the observations and thus are unable to represent low-dimensional semantics. Existing methods address this task either by encoding observations into semantics which makes it difficult to generate samples without observations, or by synthesizing the U-Net's layers of pre-trained DMs into low-dimensional semantics, which is mainly used for downstream tasks rather than using semantics to facilitate the training process. Further, those generated static representations might not be aligned with dynamic timestep-wise intermediate latents. This work introduces a Progressive self-encoded Diffusion model (ProgDiffusion), which simultaneously learns semantic representations and reconstructs observations, does efficient unconditional generation, and produces progressively structured semantic representations. These benefits are gained by a novel self-encoder mechanism which takes the U-Net's upsampling features, intermediate latent and the denoising timestep as conditions to generate time-specific semantic representations, differing from existing work of conditioning on observations only. As a result, the learned intermediate latents are dynamic and mapped to a series of semantic representations that capture their gradual changes. Notably, our proposed encoder operates independently of the observations, making it feasible for unconditional generation as observations are not required. To evaluate ProgDiffusion, we design tasks to visualise the learned progressive semantic representations, in addition to other common tasks, which validate the effectiveness of ProgDiffusion against the state-of-the-art. The code is available at https://github.com/amasawa/ProgDiffusion.
FairCDR: Transferring Fairness and User Preferences for Cross-Domain Recommendation
Authors: Yongxuan Wu, Yang Liu, Xixun Lin, Hong Zhou, Yanan Cao, Lixin Zou, Yanmin Shang, Yanbing Liu
Venue: KDD
Year: 2025

Cross-domain recommendation (CDR) has gained significant attention for its ability to address data sparsity issue. However, most existing CDR methods focus primarily on improving recommendation accuracy while largely overlooking fairness considerations, which can lead to biased outcomes and unfair treatment of different user groups. To solve this critical problem, we investigate whether fairness can be transferred from the source domain to the target domain. Our analysis suggests that fairness can be effectively transferred if the fairness of the source domain is ensured and the distributions of the source and target domains are well aligned. Based on this, we propose the FairCDR, a novel framework that can achieve the knowledge transfer of fairness and user preferences simultaneously. FairCDR owns two phases: single-domain fairness guarantee and inter-domain distribution alignment. In the first phase, we employ an adversarial learning-based recommender (ALR) to disentangle user preferences from sensitive attributes in the source domain. In the second phase, we introduce a new mutual learning-based diffusion model (MLDiff), which engages in mutual learning with ALR to progressively align the distributions of the source and target domains. This improves ALR's adaptability to distribution shifts, ultimately ensuring fairness and recommendation performance in the target domain. Extensive experiments on multiple real-world cross-domain datasets demonstrate that FairCDR surpasses existing strong baselines in both fairness and recommendation quality.
Self-Regularization with Sparse Autoencoders for Controllable LLM-based Classification
Authors: Xuansheng Wu, Wenhao Yu, Xiaoming Zhai, Ninghao Liu
Venue: KDD
Year: 2025

Modern text classification methods heavily rely on contextual embeddings from large language models (LLMs). Compared to human-engineered features, these embeddings provide automatic and effective representations for classification model training. However, they also introduce a challenge: we lose the ability to manually remove unintended features, such as sensitive or task-irrelevant features, to guarantee regulatory compliance or improve the generalizability of classification models. This limitation arises because LLM embeddings are opaque and difficult to interpret. In this paper, we propose a novel framework to identify and regularize unintended features in the LLM latent space. Specifically, we first pre-train a sparse autoencoder (SAE) to extract interpretable features from LLM latent spaces. To ensure the SAE can capture task-specific features, we further fine-tune it on task-specific datasets. In training the classification model, we propose a simple and effective regularizer, by minimizing the similarity between the classifier weights and the identified unintended feature, to remove the impact of these unintended features on classification. We evaluate the proposed framework on three real-world tasks, including toxic chat detection, reward modeling, and disease diagnosis. Results show that the proposed self-regularization framework can improve the classifier's generalizability by regularizing those features that are not semantically correlated to the task. This work pioneers controllable text classification on LLM latent spaces by leveraging interpreted features to address generalizability, fairness, and privacy challenges. The code and data are publicly available at https://github.com/JacksonWuxs/Controllable_LLM_Classifier.
GAS: Large-Scale Heterogeneous Personalization in Social Network Applications at Meta
Authors: Yihan Wu, Mingze Gao, Haoran Liu, Weiwei Li, Kevin Han, Junfeng Pan, Xinyi Zhang, Jiawei Wen, Gedi Zhou
Venue: KDD
Year: 2025

In this paper, we introduce the Generalized Auto Segmentation (GAS), an end-to-end, cross-domain personalization platform developed at Meta. GAS is designed to optimize personalization policies for online experiments, operating independently of any specific server infrastructure. Our process begins with a seed experiment to collect user data, which is followed by feature logging and selection. User segmentation is then performed using a feature-threshold method. Specifically, we utilize simple combinations of single or dual features to identify concise, explainable, and sustainable user cohorts that enhance both business outcomes and user experience over the long term. Treatments and the reward function for these segments are refined through ParallAX, a novel methodology at Meta that uses offline estimates to optimize online metrics, ensuring impactful and precisely tailored interventions for diverse user groups. The deployment of GAS across various Meta productions has demonstrated its efficiency and effectiveness.
IU4Rec: Interest Unit-Based Product Organization and Recommendation for E-Commerce Platform
Authors: Wenhao Wu, Xiaojie Li, Lin Wang, Jialiang Zhou, Di Wu, Qinye Xie, Qingheng Zhang, Yin Zhang, Shuguang Han, Fei Huang, Jufeng Chen
Venue: KDD
Year: 2025

Most recommendation systems typically follow a product-based paradigm utilizing user-product interactions to identify the most engaging items for users. However, this product-based paradigm has notable drawbacks for Xianyu~. Xianyu is China's largest online C2C e-commerce platform where a large portion of the product are post by individual sellers. Most of the product on Xianyu posted from individual sellers often have limited stock available for distribution, and once the product is sold, it's no longer available for distribution. This result in most items distributed product on Xianyu having relatively few interactions, affecting the effectiveness of traditional recommendation depending on accumulating user-item interactions. To address these issues, we introduce IU4Rec, an Interest Unit-based two-stage Recommendation system framework. We first group products into clusters based on attributes such as category, image, and semantics. These IUs are then integrated into the Recommendation system, delivering both product and technological innovations. IU4Rec begins by grouping products into clusters based on attributes such as category, image, and semantics, forming Interest Units (IUs). Then we redesign the recommendation process into two stages. In the first stage, the focus is on recommend these Interest Units, capturing broad-level interests. In the second stage, it guides users to find the best option among similar products within the selected Interest Unit. User-IU interactions are incorporated into our ranking models, offering the advantage of more persistent IU behaviors compared to item-specific interactions. This interest unit based recommendation can be beneficial from mitigating the side effect of limited-stock problem, since most interaction can be gathered on interest units which can persist and accumulate over time. Experimental results on the production dataset and online A/B testing demonstrate the effectiveness and superiority of our proposed IU-centric recommendation approach. This study not only advances recommendation technologies but also emphasizes the potential for co-evolution between product innovations and the technologies involved in item supply and distribution.
Classifying Treatment Responders: Bounds and Algorithms
Authors: Anpeng Wu, Haoxuan Li, Chunyuan Zheng, Kun Kuang, Kun Zhang
Venue: KDD
Year: 2025

Treatment responders are individuals whose outcomes would change from negative to positive if treated, and learning a classifier to predict responders would help causal decision-making in real applications. Although many treatment effect estimation methods have been proposed to identify treatment responders, there are fundamental differences between treatment effect estimation and treatment responder classification, including: (1) accurate causal effect estimation is not necessary for optimal intervention decisions; (2) methods for accurate causal effect estimation do not directly optimize classification loss; (3) treatment responder classification requires identifying joint potential outcomes, while treatment effect estimation focuses on marginal distributions. To fill this gap, we tackle the treatment responder classification problem without assuming monotonicity. We derive sharp bounds of the probability that an individual is a responder and determine a sharp upper bound on the weighted classification risk to measure the worst classification performance. Based on these findings, we further propose a Classifying Treatment Responder Learning (CTRL) algorithm to accurately identify the treatment responders, and theoretically demonstrate the superiority of jointly learning over two-stage learning. Extensive experiments on semi-synthetic and real-world datasets show that our method better predicts treatment responders and adaptively trades off false-positives and false-negatives with varying weight coefficients.
Aligning and Balancing ID and Multimodal Representations for Recommendation
Authors: Binrui Wu, Shisong Tang, Fan Li, Bing Han, Chang Meng, Jingyu Xiao, Jiechao Gao
Venue: KDD
Year: 2025

Large-scale recommendation systems mainly rely on sparse ID features, struggling with data sparsity. It's important to use multimodal information to assist ID learning for better performance. However, there exists two challenges: (1) distribution discrepancy between multimodal and ID makes direct integration prone to user-item mismatch; (2) slower convergence of multimodal representations compared to ID, causing optimization imbalance under a unified objective, which limits the potential of multimodal representations. In this paper, we comprehensively investigate the two problems and proposes a framework named AB-Rec to align and balance ID and multimodal representations learning for recommendation. We design three alignment tasks to fine-tune a pre-trained multimodal large language model (MLLM), which is then utilized to generate a unified multimodal representation for each item. AB-Rec aligns the distributions of ID and multimodal representations by minimizing the in-batch Wasserstein distance, and maximizes the distance between the two types of representations for the same item to avoid representation collapse. To solve the optimization imbalance, we propose a gradient modulation method that adaptively controls the optimization process by monitoring the contribution differences between ID and multimodal representations. Finally, we conduct extensive offline experiments on four datasets and an A/B test on an online video platform, demonstrating the effectiveness and scalability of our proposed method.
A Neuro-Symbolic Approach to Symbol Grounding for ALC-Ontologies
Authors: Xuan Wu, Yizheng Zhao
Venue: KDD
Year: 2025

Neuro-symbolic computing aims to integrate neural learning with symbolic reasoning to address the fundamental challenge of symbol grounding. While neural networks excel at pattern recognition, they struggle to maintain logical consistency. Conversely, symbolic systems provide formal reasoning capabilities but lack mechanisms for handling perceptual uncertainty. This paper introduces EmALC , a novel neuro-symbolic framework that bridges neural perception with symbolic logic through differentiable fuzzy semantics. Our approach addresses a key limitation of existing methods: while previous neuro-symbolic approaches like Logic Tensor Networks employ first-order fuzzy logic, where key reasoning problems are undecidable, EmALC ensures decidable reasoning by leveraging a fuzzy variant of ALC -- a decidable fragment of first-order logic. Unlike previous approaches that often compromise logical soundness for learning capability, EmALC maintains provable semantic consistency through a hierarchical loss function while mitigating reasoning shortcuts via rule-based revision strategies. Experimental evaluation demonstrates EmALC's effectiveness: on ontology revision tasks, it achieves 100% success rate in correcting masked groundings while preserving semantic integrity; on semantic image interpretation tasks, it improves object classification F1-scores by up to 5.56% through ontology-guided knowledge revision.