Results 61 to 70 of about 7,436,694 (204)

A Fast DFA Algorithm for Multifractal Multiscale Analysis of Physiological Time Series

Frontiers in Physiology, 2019
Detrended fluctuation analysis (DFA) is a popular tool in physiological and medical studies for estimating the self-similarity coefficient, α, of time series. Recent researches extended its use for evaluating multifractality (where α is a function of the
Paolo Castiglioni, Andrea Faini
doaj   +1 more source

Analysis of the effect of COVID‐19 on crude oil and agricultural commodity market relationships

Journal of the Agricultural and Applied Economics Association, EarlyView.
Abstract This study examines the COVID‐19 pandemic's effect on relationships between crude oil and agricultural commodity markets. Using a Time‐Varying Parameter Vector Autoregressive model, we find strong volatility transmission, with Brent, WTI, corn, and soybean prices acting as net shock transmitters, while cotton and wheat are net receivers ...
Derick Adu, Darren Hudson, Khondoker Abdul Mottaleb   +2 more
wiley   +1 more source

Parkinson's Disease and Retinal Age Gap: A Cross‐Sectional Analysis

Movement Disorders, EarlyView.
Abstract Background Deep‐learning models are capable of predicting age from retinal scans and the difference between this and chronological age, retinal age gap, has been shown to be significantly associated with risk of mortality, cardiovascular diseases, and kidney failure.
Akshay Narayan, Oscar Earle, Yukun Zhou, Axel Petzold, Rimona S. Weil, Alastair K. Denniston, Anthony P. Khawaja, Pearse A. Keane, Zhuoting Zhu, Siegfried K. Wagner   +9 more
wiley   +1 more source

Moments of the weighted Cantor measures

Demonstratio Mathematica, 2019
Based on the seminal work of Hutchinson, we investigate properties of α-weighted Cantor measures whose support is a fractal contained in the unit interval.
Harding Steven N., Riasanovsky Alexander W. N.   +1 more
doaj   +1 more source

On the analyzing of bifurcation properties of the one‐dimensional Mackey–Glass model by using a generalized approach

Mathematical Methods in the Applied Sciences, EarlyView.
The goal of this work is to look at how a nonlinear model describes hematopoiesis and its complexities utilizing commonly used techniques with historical and material links. Based on time delay, the Mackey–Glass model is explored in two instances. To offer a range, the relevance of the parameter impacting stability (bifurcation) is recorded.
Shuai Zhang, Yaya Wang, Hongyin Geng, Wei Gao, Esin Ilhan, Haci Mehmet Baskonus   +5 more
wiley   +1 more source

Dynamic Analysis of Electrically Assisted Turbocharger Rotor Considering Contact Effects in Nut Structures

International Journal of Mechanical System Dynamics, EarlyView.
ABSTRACT The rotor system of an electrically assisted turbocharger (EAT) is composed of multiple shaft components; The nonlinear connection and contact effects make it difficult to determine the system dynamic characteristics. To improve the modeling accuracy of EAT rotor system and evaluate the influence of contact between multi‐axis components and ...
Wenchao Liang, Shuqian Cao, Xiaolin Cao, Mingyue Hu, Yanhong Kang, Tianyou Wang   +5 more
wiley   +1 more source

Fixed point theorem and iterated function system in φ-metric modular space

Fixed Point Theory and Algorithms for Sciences and Engineering
We introduce and study the concept of φ-metric modular space and, then define φ-α-Meir-Keeler contraction on it and explore its fixed point. Further, we define the Hausdorff distance between two non-empty compact subsets of the considered space.
Bikramjit Acharjee, Guru Prem Prasad M
doaj   +1 more source

Inferring Inter‐Well Fracture Interactions in Unconventional Reservoirs Using Fiber‐Optic Sensing and Coupled Multiphysics Modelling

International Journal for Numerical and Analytical Methods in Geomechanics, EarlyView.
ABSTRACT Integrating distributed temperature sensing (DTS) and distributed acoustic sensing (DAS) data with numerical simulations to analyze inter‐well interference and production responses remains challenging. This study employs a coupled thermal–hydraulic–mechanical simulation framework to model heat transfer, fluid flow, and geomechanical responses ...
Chuanyao Zhong, Jiahui Chen, Juliana Y. Leung, Mirko van der Baan   +3 more
wiley   +1 more source

Environmental Stressors Influence Spatial Complexity in a Fluvial Macrophyte meadow

Remote Sensing in Ecology and Conservation, EarlyView.
This research investigates the nonlinear relationships between environmental stressors and the fine‐scale spatial complexity of a fluvial macrophytes meadow. The use of multivariate spatial analysis allowed us to identify two major environmental gradients (nutrients and light) and two major complexity gradients (related to abundance and fragmentation).
Arthur de Grandpré, Christophe Kinnard, Andrea Bertolo   +2 more
wiley   +1 more source

Stochastic processes and mean square calculus on fractal curves

In this paper, random and stochastic processes are defined on fractal curves. Fractal calculus is used to define the cumulative distribution function, probability density function, moments, variance, and correlation function of stochastic processes on ...
Serpa, Cristina, Stamova, Ivanka, Welch, Kerri, Khalili Golmankhaneh, Alireza   +3 more
core   +1 more source