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Related papers: On multifractals: a non-linear study of actigraphy…

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Sleep behaviour and in-bed movements contain rich information on the neurophysiological health of people, and have a direct link to the general well-being and quality of life. Standard clinical practices rely on polysomnography for sleep…

Signal Processing · Electrical Eng. & Systems 2023-01-10 Omar Elnaggar , Roselina Arelhi , Frans Coenen , Andrew Hopkinson , Lyndon Mason , Paolo Paoletti

We propose an analysis of heart rate marathon runners implemented by computing a multifractal spectrum based on p-exponents. We draw physiological conclusions about their performance. Finally, we link this analysis with the disturbances of…

Biological Physics · Physics 2022-06-24 Guillaume Saës , Wejdene Ben Nasr , Stéphane Jaffard , Florent Palacin , Véronique Billat

User activity fluctuations reflect the performance of online society. We investigate the statistical properties of 1-min user activity time series of simultaneously online users inhabited in 95 independent virtual worlds. The number of…

Physics and Society · Physics 2019-02-19 Yan-Hong Yang , Wen-Jie Xie , Ming-Xia Li , Zhi-Qiang Jiang , Wei-Xing Zhou

Atrial fibrillation (AF) increases the risk of stroke by a factor of four to five and is the most common abnormal heart rhythm. The progression of AF with age, from short self-terminating episodes to persistence, varies between individuals…

Tissues and Organs · Quantitative Biology 2016-10-12 Kishan A. Manani , Kim Christensen , Nicholas S. Peters

Magnetoencephalographic (MEG) recordings from a large normative cohort (n = 619) were processed to extract measures of regional neuroelectric activity. The overall objective of the effort was to use these measures to identify normative…

Neurons and Cognition · Quantitative Biology 2018-11-20 Don Krieger , Paul Shepard , David O. Okonkwo

Functional MRI is a neuroimaging technique that analyzes the functional activity of the brain by measuring blood-oxygen-level-dependent signals throughout the brain. The derived functional features can be used for investigating brain…

Neurons and Cognition · Quantitative Biology 2026-02-16 Giorgio Dolci , Silvia Saglia , Lorenza Brusini , Vince D. Calhoun , Ilaria Boscolo Galazzo , Gloria Menegaz

A variety of resting state neuroimaging data tend to exhibit fractal behavior where its power spectrum follows power-law scaling. Resting state functional connectivity is significantly influenced by fractal behavior which may not directly…

Applications · Statistics 2012-08-16 Wonsang You , Sophie Achard , Jörg Stadler , Bernd Brückner , Udo Seiffert

Functional Magnetic Resonance Imaging (fMRI) is commonly utilized to study human brain activity, including abnormal functional properties related to neurodegenerative diseases. This study aims to investigate the differences in the…

Neurons and Cognition · Quantitative Biology 2023-05-17 Yongcheng Yao

Despite the widespread diffusion of nonlinear methods for heart rate variability (HRV) analysis, the presence and the extent to which nonlinear dynamics contribute to short-term HRV is still controversial. This work aims at testing the…

We develop a method for the multifractal characterization of nonstationary time series, which is based on a generalization of the detrended fluctuation analysis (DFA). We relate our multifractal DFA method to the standard partition…

Data Analysis, Statistics and Probability · Physics 2009-11-07 Jan W. Kantelhardt , Stephan A. Zschiegner , Eva Koscielny-Bunde , Armin Bunde , Shlomo Havlin , H. Eugene Stanley

The frequency-domain properties of nonstationary functional time series often contain valuable information. These properties are characterized through its time-varying power spectrum. Practitioners seeking low-dimensional summary measures…

Methodology · Statistics 2021-03-12 Pramita Bagchi , Scott A. Bruce

In the last two decades, functional magnetic resonance imaging (fMRI) has emerged as one of the most effective technologies in clinical research of the human brain. fMRI allows researchers to study healthy and pathological brains while they…

Neurons and Cognition · Quantitative Biology 2022-12-06 Sadi Md. Redwan , Md Palash Uddin , Muhammad Imran Sharif , Anwaar Ulhaq

Parkinson disease (PD) is marked by progressive neurodegeneration, yet early and subtle structural alterations in brain tissue remain difficult to detect with conventional imaging and analytical methods. Fractal and multifractal frameworks…

Medical Physics · Physics 2025-12-09 Santanu Maity , Mousa Alrubayan , Mohammad Moshahid Khan , Prabhakar Pradhan

Multifractal time series analysis is a approach that shows the possible complexity of the system. Nowadays, one of the most popular and the best methods for determining multifractal characteristics is Multifractal Detrended Fluctuation…

Statistical Finance · Quantitative Finance 2015-10-20 Rafal Rak , Pawel Zięba

We perform an extensive empirical analysis of scaling properties of equity returns, suggesting that financial data show time varying multifractal properties. This is obtained by comparing empirical observations of the weighted generalised…

Statistical Finance · Quantitative Finance 2015-06-12 Raffaello Morales , T. Di Matteo , Tomaso Aste

Emotion Recognition from EEG signals has long been researched as it can assist numerous medical and rehabilitative applications. However, their complex and noisy structure has proven to be a serious barrier for traditional modeling methods.…

Signal Processing · Electrical Eng. & Systems 2021-12-15 Kleanthis Avramidis , Athanasia Zlatintsi , Christos Garoufis , Petros Maragos

Time series of heartbeat activity of humans can exhibit long-range correlations. In this paper we show that such kind of correlations can exist for the heartbeat activity of much simpler species like Drosophila melanogaster. By means of the…

Data Analysis, Statistics and Probability · Physics 2015-06-26 Nikolay K. Vitanov , Elka D. Yankulova

We developed a ResNet-based human activity recognition (HAR) model with minimal overhead to detect gait versus non-gait activities and everyday activities (walking, running, stairs, standing, sitting, lying, sit-to-stand transitions). The…

Fluctuations in heart rate are intimately tied to changes in the physiological state of the organism. We examine and exploit this relationship by classifying a human subject's wake/sleep status using his instantaneous heart rate (IHR)…

Applications · Statistics 2018-08-02 John Malik , Yu-Lun Lo , Hau-tieng Wu

Human Activity Recognition (HAR) is one of the fundamental building blocks of human assistive devices like orthoses and exoskeletons. There are different approaches to HAR depending on the application. Numerous studies have been focused on…

Human-Computer Interaction · Computer Science 2024-03-08 Farhad Nazari , Darius Nahavandi , Navid Mohajer , Abbas Khosravi