Feature Encoding with AutoEncoders for Weakly-supervised Anomaly Detection

Abstract

Weakly-supervised anomaly detection aims at learning an anomaly detector from a limited amount of labeled data and abundant unlabeled data. Recent works build deep neural networks for anomaly detection by discriminatively mapping the normal samples and abnormal samples to different regions in the feature space or fitting different distributions. However, due to the limited number of annotated anomaly samples, directly training networks with the discriminative loss may not be sufficient. To overcome this issue, this paper proposes a novel strategy to transform the input data into a more meaningful representation that could be used for anomaly detection. Specifically, we leverage an autoencoder to encode the input data and utilize three factors, hidden representation, reconstruction residual vector, and reconstruction error, as the new representation for the input data. This representation amounts to encode a test sample with its projection on the training data manifold, its direction to its projection and its distance to its projection. In addition to this encoding, we also propose a novel network architecture to seamlessly incorporate those three factors. From our extensive experiments, the benefits of the proposed strategy are clearly demonstrated by its superior performance over the competitive methods.

12pages,4 figures, published by IEEE Transactions on Neural Networks and Learning Systems,2021

References in corpus (7)

• Deep Learning for Anomaly Detection: A Review
• Unsupervised Anomaly Detection via Variational Auto-Encoder for Seasonal KPIs in Web Applications
• Unsupervised and Semi-supervised Anomaly Detection with LSTM Neural Networks
• Learning Representations of Ultrahigh-dimensional Data for Random Distance-based Outlier Detection
• Active Learning for Wireless IoT Intrusion Detection
• Deep Weakly-supervised Anomaly Detection
• Deep Anomaly Detection with Deviation Networks

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