通过密度演化中的位移差异检测异常,对噪声和异常类型变化鲁棒。
Anomaly Detection via Mean Shift Density Enhancement
- 基于流形学习构建自适应邻域图,用加权均值漂移追踪样本位移。
- 在46个真实数据集上优于13种基线方法,多噪声水平下表现稳定。
- 适合处理复杂分布、高噪声场景下的通用异常检测任务。
无监督异常检测是机器学习中的重要问题。现有算法通常仅在特定结构假设下表现良好,且在噪声环境下鲁棒性差。本文提出一种完全无监督的框架——均值漂移密度增强(MSDE),通过异常样本在密度驱动流形演化中的几何响应来检测异常。正常样本因局部密度支撑强而保持稳定,异常样本则因被吸引至附近密度峰而产生显著累积位移。为实现该思路,MSDE采用基于流形学习的模糊邻域图构建自适应样本特异性密度权重,并执行加权均值漂移。我们在包含46个真实世界表格数据集、四种真实异常生成机制及六种噪声水平的基准上评估了该方法。与13种主流无监督基线相比,MSDE在多个标准分类指标上均表现出一致、均衡且稳健的性能,适用于多种异常类型与噪声水平。结果表明,基于位移的评分策略为无监督异常检测提供了比现有最优方法更鲁棒的替代方案。
原文摘要 · Abstract (English)
Unsupervised anomaly detection stands as an important problem in machine learning. Existing unsupervised anomaly detection algorithms rarely perform well across different anomaly types, often excelling only under specific structural assumptions. This lack of robustness also becomes particularly evident under noisy settings. We propose Mean Shift Density Enhancement (MSDE), a fully unsupervised framework that detects anomalies through their geometric response to density-driven manifold evolution. MSDE is designed as a general purpose anomaly detection framework, based on the principle that normal samples, being well supported by local density, remain stable under iterative density enhancement, whereas anomalous samples undergo large cumulative displacements as they are attracted toward nearby density modes. To operationalize this idea, MSDE employs a weighted mean-shift procedure with adaptive, sample-specific density weights derived from a manifold learning-based fuzzy neighborhood graph. We evaluate MSDE on an anomaly detection benchmark comprising 46 real-world tabular datasets, four realistic anomaly generation mechanisms, and six noise levels. Compared to 13 established unsupervised baselines, MSDE achieves consistently strong, balanced and robust performance for several standard classification metrics, at several noise levels and on average over several types of anomalies. These results demonstrate that displacement-based scoring provides a robust alternative to the existing state-of-the-art for unsupervised anomaly detection.
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。