Calibrated Unsupervised Anomaly Detection in Multivariate Time-series using Reinforcement Learning

Fuente: arXiv
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Auteurs principaux: Sanami, Saba, Aghdam, Amir G.
Format: Preprint
Publié: 2025
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author Sanami, Saba
Aghdam, Amir G.
author_facet Sanami, Saba
Aghdam, Amir G.
contents This paper investigates unsupervised anomaly detection in multivariate time-series data using reinforcement learning (RL) in the latent space of an autoencoder. A significant challenge is the limited availability of anomalous data, often leading to misclassifying anomalies as normal events, thus raising false negatives. RL can help overcome this limitation by promoting exploration and balancing exploitation during training, effectively preventing overfitting. Wavelet analysis is also utilized to enhance anomaly detection, enabling time-series data decomposition into both time and frequency domains. This approach captures anomalies at multiple resolutions, with wavelet coefficients extracted to detect both sudden and subtle shifts in the data, thereby refining the anomaly detection process. We calibrate the decision boundary by generating synthetic anomalies and embedding a supervised framework within the model. This supervised element aids the unsupervised learning process by fine-tuning the decision boundary and increasing the model's capacity to distinguish between normal and anomalous patterns effectively.
format Preprint
id arxiv_https___arxiv_org_abs_2502_03245
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Calibrated Unsupervised Anomaly Detection in Multivariate Time-series using Reinforcement Learning
Sanami, Saba
Aghdam, Amir G.
Machine Learning
Systems and Control
Signal Processing
This paper investigates unsupervised anomaly detection in multivariate time-series data using reinforcement learning (RL) in the latent space of an autoencoder. A significant challenge is the limited availability of anomalous data, often leading to misclassifying anomalies as normal events, thus raising false negatives. RL can help overcome this limitation by promoting exploration and balancing exploitation during training, effectively preventing overfitting. Wavelet analysis is also utilized to enhance anomaly detection, enabling time-series data decomposition into both time and frequency domains. This approach captures anomalies at multiple resolutions, with wavelet coefficients extracted to detect both sudden and subtle shifts in the data, thereby refining the anomaly detection process. We calibrate the decision boundary by generating synthetic anomalies and embedding a supervised framework within the model. This supervised element aids the unsupervised learning process by fine-tuning the decision boundary and increasing the model's capacity to distinguish between normal and anomalous patterns effectively.
title Calibrated Unsupervised Anomaly Detection in Multivariate Time-series using Reinforcement Learning
topic Machine Learning
Systems and Control
Signal Processing
url https://arxiv.org/abs/2502.03245