Identification of anomalous diffusion sources by unsupervised learning

Fractional Brownian motion (fBm) is a ubiquitous diffusion process in which the memory effects of the stochastic transport result in the mean-squared particle displacement following a power law 〈Δr^{2}〉∼t^{α}, where the diffusion exponent α characterizes whether the transport is subdiffusive (α<1...

Full description

Bibliographic Details
Main Authors: Raviteja Vangara, Kim Ø. Rasmussen, Dimiter N. Petsev, Golan Bel, Boian S. Alexandrov
Format: Article
Language:English
Published: American Physical Society 2020-05-01
Series:Physical Review Research
Online Access:http://doi.org/10.1103/PhysRevResearch.2.023248
_version_ 1797211439021162496
author Raviteja Vangara
Kim Ø. Rasmussen
Dimiter N. Petsev
Golan Bel
Boian S. Alexandrov
author_facet Raviteja Vangara
Kim Ø. Rasmussen
Dimiter N. Petsev
Golan Bel
Boian S. Alexandrov
author_sort Raviteja Vangara
collection DOAJ
description Fractional Brownian motion (fBm) is a ubiquitous diffusion process in which the memory effects of the stochastic transport result in the mean-squared particle displacement following a power law 〈Δr^{2}〉∼t^{α}, where the diffusion exponent α characterizes whether the transport is subdiffusive (α<1), diffusive (α=1), or superdiffusive (α>1). Due to the abundance of fBm processes in nature, significant efforts have been devoted to the identification and characterization of fBm sources in various phenomena. In practice, the identification of the fBm sources often relies on solving a complex and ill-posed inverse problem based on limited observed data. In the general case, the detected signals are formed by an unknown number of release sources, located at different locations and with different strengths, that act simultaneously. This means that the observed data are composed of mixtures of releases from an unknown number of sources, which makes the traditional inverse modeling approaches unreliable. Here, we report an unsupervised learning method, based on non-negative matrix factorization, that enables the identification of the unknown number of release sources as well the anomalous diffusion characteristics based on limited observed data and the general form of the corresponding fBm Green's function. We show that our method performs accurately for different types of sources and configurations with a predetermined number of sources with specific characteristics and introduced noise.
first_indexed 2024-04-24T10:26:30Z
format Article
id doaj.art-ef46d722768f4240ab8a513696481e19
institution Directory Open Access Journal
issn 2643-1564
language English
last_indexed 2024-04-24T10:26:30Z
publishDate 2020-05-01
publisher American Physical Society
record_format Article
series Physical Review Research
spelling doaj.art-ef46d722768f4240ab8a513696481e192024-04-12T16:54:43ZengAmerican Physical SocietyPhysical Review Research2643-15642020-05-012202324810.1103/PhysRevResearch.2.023248Identification of anomalous diffusion sources by unsupervised learningRaviteja VangaraKim Ø. RasmussenDimiter N. PetsevGolan BelBoian S. AlexandrovFractional Brownian motion (fBm) is a ubiquitous diffusion process in which the memory effects of the stochastic transport result in the mean-squared particle displacement following a power law 〈Δr^{2}〉∼t^{α}, where the diffusion exponent α characterizes whether the transport is subdiffusive (α<1), diffusive (α=1), or superdiffusive (α>1). Due to the abundance of fBm processes in nature, significant efforts have been devoted to the identification and characterization of fBm sources in various phenomena. In practice, the identification of the fBm sources often relies on solving a complex and ill-posed inverse problem based on limited observed data. In the general case, the detected signals are formed by an unknown number of release sources, located at different locations and with different strengths, that act simultaneously. This means that the observed data are composed of mixtures of releases from an unknown number of sources, which makes the traditional inverse modeling approaches unreliable. Here, we report an unsupervised learning method, based on non-negative matrix factorization, that enables the identification of the unknown number of release sources as well the anomalous diffusion characteristics based on limited observed data and the general form of the corresponding fBm Green's function. We show that our method performs accurately for different types of sources and configurations with a predetermined number of sources with specific characteristics and introduced noise.http://doi.org/10.1103/PhysRevResearch.2.023248
spellingShingle Raviteja Vangara
Kim Ø. Rasmussen
Dimiter N. Petsev
Golan Bel
Boian S. Alexandrov
Identification of anomalous diffusion sources by unsupervised learning
Physical Review Research
title Identification of anomalous diffusion sources by unsupervised learning
title_full Identification of anomalous diffusion sources by unsupervised learning
title_fullStr Identification of anomalous diffusion sources by unsupervised learning
title_full_unstemmed Identification of anomalous diffusion sources by unsupervised learning
title_short Identification of anomalous diffusion sources by unsupervised learning
title_sort identification of anomalous diffusion sources by unsupervised learning
url http://doi.org/10.1103/PhysRevResearch.2.023248
work_keys_str_mv AT ravitejavangara identificationofanomalousdiffusionsourcesbyunsupervisedlearning
AT kimørasmussen identificationofanomalousdiffusionsourcesbyunsupervisedlearning
AT dimiternpetsev identificationofanomalousdiffusionsourcesbyunsupervisedlearning
AT golanbel identificationofanomalousdiffusionsourcesbyunsupervisedlearning
AT boiansalexandrov identificationofanomalousdiffusionsourcesbyunsupervisedlearning