Evolving Markov Chains: Unsupervised Mode Discovery and Recognition from Data Streams

Fuente: arXiv
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Main Authors: Coşkun, Kutalmış, Tümer, Borahan, Hiller, Bjarne C., Becker, Martin
Format: Preprint
Published: 2024
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author Coşkun, Kutalmış
Tümer, Borahan
Hiller, Bjarne C.
Becker, Martin
author_facet Coşkun, Kutalmış
Tümer, Borahan
Hiller, Bjarne C.
Becker, Martin
contents Markov chains are simple yet powerful mathematical structures to model temporally dependent processes. They generally assume stationary data, i.e., fixed transition probabilities between observations/states. However, live, real-world processes, like in the context of activity tracking, biological time series, or industrial monitoring, often switch behavior over time. Such behavior switches can be modeled as transitions between higher-level \emph{modes} (e.g., running, walking, etc.). Yet all modes are usually not previously known, often exhibit vastly differing transition probabilities, and can switch unpredictably. Thus, to track behavior changes of live, real-world processes, this study proposes an online and efficient method to construct Evolving Markov chains (EMCs). EMCs adaptively track transition probabilities, automatically discover modes, and detect mode switches in an online manner. In contrast to previous work, EMCs are of arbitrary order, the proposed update scheme does not rely on tracking windows, only updates the relevant region of the probability tensor, and enjoys geometric convergence of the expected estimates. Our evaluation of synthetic data and real-world applications on human activity recognition, electric motor condition monitoring, and eye-state recognition from electroencephalography (EEG) measurements illustrates the versatility of the approach and points to the potential of EMCs to efficiently track, model, and understand live, real-world processes.
format Preprint
id arxiv_https___arxiv_org_abs_2411_17528
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Evolving Markov Chains: Unsupervised Mode Discovery and Recognition from Data Streams
Coşkun, Kutalmış
Tümer, Borahan
Hiller, Bjarne C.
Becker, Martin
Machine Learning
Markov chains are simple yet powerful mathematical structures to model temporally dependent processes. They generally assume stationary data, i.e., fixed transition probabilities between observations/states. However, live, real-world processes, like in the context of activity tracking, biological time series, or industrial monitoring, often switch behavior over time. Such behavior switches can be modeled as transitions between higher-level \emph{modes} (e.g., running, walking, etc.). Yet all modes are usually not previously known, often exhibit vastly differing transition probabilities, and can switch unpredictably. Thus, to track behavior changes of live, real-world processes, this study proposes an online and efficient method to construct Evolving Markov chains (EMCs). EMCs adaptively track transition probabilities, automatically discover modes, and detect mode switches in an online manner. In contrast to previous work, EMCs are of arbitrary order, the proposed update scheme does not rely on tracking windows, only updates the relevant region of the probability tensor, and enjoys geometric convergence of the expected estimates. Our evaluation of synthetic data and real-world applications on human activity recognition, electric motor condition monitoring, and eye-state recognition from electroencephalography (EEG) measurements illustrates the versatility of the approach and points to the potential of EMCs to efficiently track, model, and understand live, real-world processes.
title Evolving Markov Chains: Unsupervised Mode Discovery and Recognition from Data Streams
topic Machine Learning
url https://arxiv.org/abs/2411.17528