解决图数据多重缺失下的无监督异常检测难题,提升真实场景下的检测鲁棒性。
Towards Multiple Missing Values-resistant Unsupervised Graph Anomaly Detection
- 双路径编码器分别重建缺失属性与结构,避免跨视图误差传播
- 在联合隐空间中使正常节点聚类、异常节点分离,提升区分度
- 生成靠近正常区域的硬负样本,增强异常判别边界
无监督图异常检测(GAD)旨在仅利用图结构数据中的未标记节点信息识别异常模式。然而,现有方法通常假设节点属性和结构信息完整,这在现实场景中难以满足,因隐私保护、采集错误或动态节点接入导致数据缺失。传统插补方法可能将罕见异常节点‘修复’为正常形态,引入插补偏差。当属性与边同时缺失时,一视图的估计误差会污染另一视图,造成跨视图干扰,进一步降低检测性能。为此,本文提出M²V-UGAD框架,可在不完整图上实现多缺失值鲁棒的无监督图异常检测。首先设计双路径编码器,独立重构缺失属性与图结构,防止误差传播;随后在联合隐空间中融合并正则化,使正常节点聚集于紧凑内流形,异常节点分布于外层;最后,采样正常区域外的潜在编码并解码为真实节点特征与子图,生成硬负例以强化决策边界。在七个公开基准上的实验表明,该方法在不同缺失率下均优于现有无监督GAD方法。
原文摘要 · Abstract (English)
Unsupervised graph anomaly detection (GAD) has received increasing attention in recent years, which aims to identify data anomalous patterns utilizing only unlabeled node information from graph-structured data. However, prevailing unsupervised GAD methods typically presuppose complete node attributes and structure information, a condition hardly satisfied in real-world scenarios owing to privacy, collection errors or dynamic node arrivals. Existing standard imputation schemes risk "repairing" rare anomalous nodes so that they appear normal, thereby introducing imputation bias into the detection process. In addition, when both node attributes and edges are missing simultaneously, estimation errors in one view can contaminate the other, causing cross-view interference that further undermines the detection performance. To overcome these challenges, we propose M$^2$V-UGAD, a multiple missing values-resistant unsupervised GAD framework on incomplete graphs. Specifically, a dual-pathway encoder is first proposed to independently reconstruct missing node attributes and graph structure, thereby preventing errors in one view from propagating to the other. The two pathways are then fused and regularized in a joint latent space so that normals occupy a compact inner manifold while anomalies reside on an outer shell. Lastly, to mitigate imputation bias, we sample latent codes just outside the normal region and decode them into realistic node features and subgraphs, providing hard negative examples that sharpen the decision boundary. Experiments on seven public benchmarks demonstrate that M$^2$V-UGAD consistently outperforms existing unsupervised GAD methods across varying missing rates.
Thank you to arXiv for use of its open access interoperability. PaperDance 不是 arXiv 官方产品;中文卡片由大模型生成,请以原文为准。