E2USD: Efficient-yet-effective Unsupervised State Detection for Multivariate Time Series

Fuente: arXiv
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Autori principali: Lai, Zhichen, Li, Huan, Zhang, Dalin, Zhao, Yan, Qian, Weizhu, Jensen, Christian S.
Natura: Preprint
Pubblicazione: 2024
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author Lai, Zhichen
Li, Huan
Zhang, Dalin
Zhao, Yan
Qian, Weizhu
Jensen, Christian S.
author_facet Lai, Zhichen
Li, Huan
Zhang, Dalin
Zhao, Yan
Qian, Weizhu
Jensen, Christian S.
contents Cyber-physical system sensors emit multivariate time series (MTS) that monitor physical system processes. Such time series generally capture unknown numbers of states, each with a different duration, that correspond to specific conditions, e.g., "walking" or "running" in human-activity monitoring. Unsupervised identification of such states facilitates storage and processing in subsequent data analyses, as well as enhances result interpretability. Existing state-detection proposals face three challenges. First, they introduce substantial computational overhead, rendering them impractical in resourceconstrained or streaming settings. Second, although state-of-the-art (SOTA) proposals employ contrastive learning for representation, insufficient attention to false negatives hampers model convergence and accuracy. Third, SOTA proposals predominantly only emphasize offline non-streaming deployment, we highlight an urgent need to optimize online streaming scenarios. We propose E2Usd that enables efficient-yet-accurate unsupervised MTS state detection. E2Usd exploits a Fast Fourier Transform-based Time Series Compressor (fftCompress) and a Decomposed Dual-view Embedding Module (ddEM) that together encode input MTSs at low computational overhead. Additionally, we propose a False Negative Cancellation Contrastive Learning method (fnccLearning) to counteract the effects of false negatives and to achieve more cluster-friendly embedding spaces. To reduce computational overhead further in streaming settings, we introduce Adaptive Threshold Detection (adaTD). Comprehensive experiments with six baselines and six datasets offer evidence that E2Usd is capable of SOTA accuracy at significantly reduced computational overhead.
format Preprint
id arxiv_https___arxiv_org_abs_2402_14041
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle E2USD: Efficient-yet-effective Unsupervised State Detection for Multivariate Time Series
Lai, Zhichen
Li, Huan
Zhang, Dalin
Zhao, Yan
Qian, Weizhu
Jensen, Christian S.
Machine Learning
Artificial Intelligence
Databases
Cyber-physical system sensors emit multivariate time series (MTS) that monitor physical system processes. Such time series generally capture unknown numbers of states, each with a different duration, that correspond to specific conditions, e.g., "walking" or "running" in human-activity monitoring. Unsupervised identification of such states facilitates storage and processing in subsequent data analyses, as well as enhances result interpretability. Existing state-detection proposals face three challenges. First, they introduce substantial computational overhead, rendering them impractical in resourceconstrained or streaming settings. Second, although state-of-the-art (SOTA) proposals employ contrastive learning for representation, insufficient attention to false negatives hampers model convergence and accuracy. Third, SOTA proposals predominantly only emphasize offline non-streaming deployment, we highlight an urgent need to optimize online streaming scenarios. We propose E2Usd that enables efficient-yet-accurate unsupervised MTS state detection. E2Usd exploits a Fast Fourier Transform-based Time Series Compressor (fftCompress) and a Decomposed Dual-view Embedding Module (ddEM) that together encode input MTSs at low computational overhead. Additionally, we propose a False Negative Cancellation Contrastive Learning method (fnccLearning) to counteract the effects of false negatives and to achieve more cluster-friendly embedding spaces. To reduce computational overhead further in streaming settings, we introduce Adaptive Threshold Detection (adaTD). Comprehensive experiments with six baselines and six datasets offer evidence that E2Usd is capable of SOTA accuracy at significantly reduced computational overhead.
title E2USD: Efficient-yet-effective Unsupervised State Detection for Multivariate Time Series
topic Machine Learning
Artificial Intelligence
Databases
url https://arxiv.org/abs/2402.14041