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Main Authors: Spaeh, Fabian, Sotiropoulos, Konstantinos, Tsourakakis, Charalampos E.
Format: Preprint
Published: 2024
Subjects:
Online Access:https://arxiv.org/abs/2405.15094
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author Spaeh, Fabian
Sotiropoulos, Konstantinos
Tsourakakis, Charalampos E.
author_facet Spaeh, Fabian
Sotiropoulos, Konstantinos
Tsourakakis, Charalampos E.
contents This study introduces a novel approach for learning mixtures of Markov chains, a critical process applicable to various fields, including healthcare and the analysis of web users. Existing research has identified a clear divide in methodologies for learning mixtures of discrete and continuous-time Markov chains, while the latter presents additional complexities for recovery accuracy and efficiency. We introduce a unifying strategy for learning mixtures of discrete and continuous-time Markov chains, focusing on hitting times, which are well defined for both types. Specifically, we design a reconstruction algorithm that outputs a mixture which accurately reflects the estimated hitting times and demonstrates resilience to noise. We introduce an efficient gradient-descent approach, specifically tailored to manage the computational complexity and non-symmetric characteristics inherent in the calculation of hitting time derivatives. Our approach is also of significant interest when applied to a single Markov chain, thus extending the methodologies previously established by Hoskins et al. and Wittmann et al. We complement our theoretical work with experiments conducted on synthetic and real-world datasets, providing a comprehensive evaluation of our methodology.
format Preprint
id arxiv_https___arxiv_org_abs_2405_15094
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle ULTRA-MC: A Unified Approach to Learning Mixtures of Markov Chains via Hitting Times
Spaeh, Fabian
Sotiropoulos, Konstantinos
Tsourakakis, Charalampos E.
Machine Learning
This study introduces a novel approach for learning mixtures of Markov chains, a critical process applicable to various fields, including healthcare and the analysis of web users. Existing research has identified a clear divide in methodologies for learning mixtures of discrete and continuous-time Markov chains, while the latter presents additional complexities for recovery accuracy and efficiency. We introduce a unifying strategy for learning mixtures of discrete and continuous-time Markov chains, focusing on hitting times, which are well defined for both types. Specifically, we design a reconstruction algorithm that outputs a mixture which accurately reflects the estimated hitting times and demonstrates resilience to noise. We introduce an efficient gradient-descent approach, specifically tailored to manage the computational complexity and non-symmetric characteristics inherent in the calculation of hitting time derivatives. Our approach is also of significant interest when applied to a single Markov chain, thus extending the methodologies previously established by Hoskins et al. and Wittmann et al. We complement our theoretical work with experiments conducted on synthetic and real-world datasets, providing a comprehensive evaluation of our methodology.
title ULTRA-MC: A Unified Approach to Learning Mixtures of Markov Chains via Hitting Times
topic Machine Learning
url https://arxiv.org/abs/2405.15094