IMPACT: Influence Modeling for Open-Set Time Series Anomaly Detection

Fuente: arXiv
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Auteurs principaux: Zhou, Xiaohui, Wang, Yijie, Xu, Hongzuo, Liang, Weixuan, Li, Xiaoli, Pang, Guansong
Format: Preprint
Publié: 2026
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author Zhou, Xiaohui
Wang, Yijie
Xu, Hongzuo
Liang, Weixuan
Li, Xiaoli
Pang, Guansong
author_facet Zhou, Xiaohui
Wang, Yijie
Xu, Hongzuo
Liang, Weixuan
Li, Xiaoli
Pang, Guansong
contents Open-set anomaly detection (OSAD) is an emerging paradigm designed to utilize limited labeled data from anomaly classes seen in training to identify both seen and unseen anomalies during testing. Current approaches rely on simple augmentation methods to generate pseudo anomalies that replicate unseen anomalies. Despite being promising in image data, these methods are found to be ineffective in time series data due to the failure to preserve its sequential nature, resulting in trivial or unrealistic anomaly patterns. They are further plagued when the training data is contaminated with unlabeled anomalies. This work introduces $\textbf{IMPACT}$, a novel framework that leverages $\underline{\textbf{i}}$nfluence $\underline{\textbf{m}}$odeling for o$\underline{\textbf{p}}$en-set time series $\underline{\textbf{a}}$nomaly dete$\underline{\textbf{ct}}$ion, to tackle these challenges. The key insight is to $\textbf{i)}$ learn an influence function that can accurately estimate the impact of individual training samples on the modeling, and then $\textbf{ii)}$ leverage these influence scores to generate semantically divergent yet realistic unseen anomalies for time series while repurposing high-influential samples as supervised anomalies for anomaly decontamination. Extensive experiments show that IMPACT significantly outperforms existing state-of-the-art methods, showing superior accuracy under varying OSAD settings and contamination rates. Code is available at https://github.com/mala-lab/IMPACT.
format Preprint
id arxiv_https___arxiv_org_abs_2603_29183
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle IMPACT: Influence Modeling for Open-Set Time Series Anomaly Detection
Zhou, Xiaohui
Wang, Yijie
Xu, Hongzuo
Liang, Weixuan
Li, Xiaoli
Pang, Guansong
Machine Learning
Artificial Intelligence
Open-set anomaly detection (OSAD) is an emerging paradigm designed to utilize limited labeled data from anomaly classes seen in training to identify both seen and unseen anomalies during testing. Current approaches rely on simple augmentation methods to generate pseudo anomalies that replicate unseen anomalies. Despite being promising in image data, these methods are found to be ineffective in time series data due to the failure to preserve its sequential nature, resulting in trivial or unrealistic anomaly patterns. They are further plagued when the training data is contaminated with unlabeled anomalies. This work introduces $\textbf{IMPACT}$, a novel framework that leverages $\underline{\textbf{i}}$nfluence $\underline{\textbf{m}}$odeling for o$\underline{\textbf{p}}$en-set time series $\underline{\textbf{a}}$nomaly dete$\underline{\textbf{ct}}$ion, to tackle these challenges. The key insight is to $\textbf{i)}$ learn an influence function that can accurately estimate the impact of individual training samples on the modeling, and then $\textbf{ii)}$ leverage these influence scores to generate semantically divergent yet realistic unseen anomalies for time series while repurposing high-influential samples as supervised anomalies for anomaly decontamination. Extensive experiments show that IMPACT significantly outperforms existing state-of-the-art methods, showing superior accuracy under varying OSAD settings and contamination rates. Code is available at https://github.com/mala-lab/IMPACT.
title IMPACT: Influence Modeling for Open-Set Time Series Anomaly Detection
topic Machine Learning
Artificial Intelligence
url https://arxiv.org/abs/2603.29183