Detecting Anomalies in Time Series Using Kernel Density Approaches
- Zurich University of Applied Sciences, Winterthur (Switzerland)
- Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
- Texas A & M University, Commerce, TX (United States)
This paper introduces a novel anomaly detection approach tailored for time series data with exclusive reliance on normal events during training. Our key innovation lies in the application of kernel-density estimation (KDE) to scrutinize reconstruction errors, providing an empirically derived probability distribution for normal events post-reconstruction. This non-parametric density estimation technique offers a nuanced understanding of anomaly detection, differentiating it from prevalent threshold-based mechanisms in existing methodologies. In post-training, events are encoded, decoded, and evaluated against the estimated density, providing a comprehensive notion of normality. In addition, we propose a data augmentation strategy involving variational autoencoder-generated events and a smoothing step for enhanced model robustness. The significance of our autoencoder-based approach is evident in its capacity to learn normal representation without prior anomaly knowledge. Through the KDE step on reconstruction errors, our method addresses the versatility of anomalies, departing from assumptions tied to larger reconstruction errors for anomalous events. Our proposed likelihood measure then distinguishes normal from anomalous events, providing a concise yet comprehensive anomaly detection solution. The extensive experimental results support the feasibility of our proposed method, yielding significantly improved classification performance by nearly 10% on the UCR benchmark data.
- Research Organization:
- Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- National Energy Research Scientific Computing Center (NERSC); USDOE; USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR)
- Grant/Contract Number:
- AC02-05CH11231
- OSTI ID:
- 2316100
- Alternate ID(s):
- OSTI ID: 2319263
OSTI ID: 2587233
- Journal Information:
- IEEE Access, Journal Name: IEEE Access Journal Issue: 99 Vol. 12; ISSN 2169-3536
- Publisher:
- Institute of Electrical and Electronics Engineers (IEEE)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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