1. Density-Based Evaluation Metrics in Unsupervised Anomaly Detection Contexts
- Author
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Cláudia Antunes and Rui Maia
- Subjects
Computer science ,business.industry ,Anomaly (natural sciences) ,Machine learning ,computer.software_genre ,Density based ,Identification (information) ,Metric (mathematics) ,Unsupervised learning ,Anomaly detection ,Artificial intelligence ,Semantic information ,business ,computer ,Curse of dimensionality - Abstract
From cybersecurity to life sciences, anomaly detection is considered crucial as it often enables the identification of relevant semantic information that can help to prevent and detect events such as cyber attacks or patients heart-attacks. Although anomaly detection is a prominent research area it still encompasses several challenges, namely regarding results evaluation in real-world unlabelled and imbalanced datasets. This work contributes to understand and compare the behaviour of different evaluation metrics, namely classic metrics based on positive and negative rates, and density based metrics without classes information. We experiment five state-of-art anomaly detection approaches over two datasets with contrasting characteristics regarding dimensionality or contamination. Each metrics’ ability to give trustful results is analysed regarding different datasets or approaches properties focusing on the possibility of evaluating real-world unsupervised learning models using density metrics.
- Published
- 2021
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