Results 51 to 60 of about 3,881 (165)

Detrended fluctuation analysis for fractals and multifractals in higher dimensions

, 2006
One-dimensional detrended fluctuation analysis (1D DFA) and multifractal detrended fluctuation analysis (1D MF-DFA) are widely used in the scaling analysis of fractal and multifractal time series because of being accurate and easy to implement.
B. B. Mandelbrot, D. Maraun, E. Alessio, Gao-Feng Gu, H. E. Hurst, J. W. Kantelhardt, M. Holschneider, P. Grassberger, Wei-Xing Zhou   +8 more
core   +1 more source

Donor‐acceptor fractal synergy: Decoding self‐similarity for stable organic photovoltaics

FlexMat, EarlyView.
Morphological congruence between donor and acceptor refines the fractal structure of bulk heterojunction films and enhances their self‐similarity. This optimized multiscale morphology preserves charge‐transport pathways against external disturbances, suppresses structural degradation, and improves the operational stability of organic solar cells while ...
Runzheng Gu, Zhongwei Ge, Yiyun Li, Fengzhe Cui, Zhen Fu, Mingxu Zhou, Dongcheng Jiang, Jiangkai Sun, Jianqiang Liu, Kangning Zhang, Feng Chen, Hang Yin, Yanming Sun, Xiaotao Hao   +13 more
wiley   +1 more source

Towards Multifractional Calculus [PDF]

Frontiers in Physics, 2018
After motivating the need of a multiscale version of fractional calculus in quantum gravity, we review current proposals and the program to be carried out in order to reach a viable definition of scale-dependent fractional operators. We present different types of multifractional Laplacians and comment on their known or expected properties.
openaire   +4 more sources

Theoretical Predictability Limits of Spatially Anisotropic Multifractal Processes: Implications for Weather Prediction

Earth and Space Science, 2019
A correlation spectrum‐based approach is used to express the theoretical predictability limits of multifractal processes as an analytical function of their anisotropy parameters.
Arun Ramanathan, A.N.V. Satyanarayana, M. Mandal   +2 more
doaj   +1 more source

Comparing Quasi-Parallel and Quasi-Perpendicular Configuration in the Terrestrial Magnetosheath: Multifractal Analysis

Frontiers in Physics, 2022
The terrestrial magnetosheath is characterized by large-amplitude magnetic field fluctuations. In some regions, and depending on the bow-shock geometry, these can be observed on several scales, and show the typical signatures of magnetohydrodynamic ...
Alexandre Gurchumelia, Alexandre Gurchumelia, Luca Sorriso-Valvo, Luca Sorriso-Valvo, David Burgess, Emiliya Yordanova, Khatuna Elbakidze, Khatuna Elbakidze, Khatuna Elbakidze, Oleg Kharshiladze, Diana Kvaratskhelia, Diana Kvaratskhelia, Diana Kvaratskhelia   +12 more
doaj   +1 more source

FRACTAL RADIOPHYSICS. 1. THEORETICAL BASES [PDF]

Radio Physics and Radio Astronomy, 2020
Purpose: Currently, there is a tendency to “fractalize” the science. Radiophysics is no exception. The subject of this work is a review of the basic ideas of “fractalization”, the mathematical foundations of modern fractal methods for describing and ...
O. V. Lazorenko, L. F. Chernogor
doaj   +1 more source

A Comparison of Realized Measures of Integrated Volatility: Price Duration‐ vs. Return‐Based Approaches

Journal of Forecasting, EarlyView.
ABSTRACT We study the accuracy of a variety of parametric price duration‐based realized variance estimators constructed via various financial duration models and compare their forecasting performance with the performance of various nonparametric return‐based realized variance estimators.
Björn Schulte‐Tillmann, Mawuli Segnon, Timo Wiedemann   +2 more
wiley   +1 more source

MULTIFRACTAL FLUCTUATIONS IN FINANCE [PDF]

International Journal of Theoretical and Applied Finance, 2000
We consider the structure functions S(q)(τ), i.e. the moments of order q of the increments X(t + τ)-X(t) of the Foreign Exchange rate X(t) which give clear evidence of scaling (S(q)(τ)∝τζ(q)). We demonstrate that the nonlinearity of the observed scaling exponent ζ(q) is incompatible with monofractal additive stochastic models usually introduced in ...
F. Schmitt, D. Schertzer, S. Lovejoy
openaire   +4 more sources

Bridging the Scaling Gap: A Review of Nonlinear Paradigms for the Estimation and Understanding of Extreme Rainfall from Heavy Storms

Fractal and Fractional
Short-duration extreme rainfall is a major trigger of flash floods and urban inundation, yet its quantification remains a profound challenge due to the scarcity of high-resolution observations.
Kevin K. W. Cheung
doaj   +1 more source

Multifractal Analysis of the Coupling Space of Feed-Forward Neural Networks

, 1995
Random input patterns induce a partition of the coupling space of feed-forward neural networks into different cells according to the generated output sequence. For the perceptron this partition forms a random multifractal for which the spectrum $f(\alpha)
A. Engel, A. Engel, B. B. Mandelbrot, B. Derrida, D. Haussler, E. Gardner, E. Gardner, G. Györgyi, G. Györgyi, G. Paladin, J. A. Hertz, J. Feder, J. Feder, J. R. L. de Almeida, M. Biehl, M. H. Jensen, M. Mezard, M. Opper, M. S. Seung, M. Weigt, P. Grassberger, R. Benzi, R. Monasson, R. Monasson, T. C. Halsey, T. M. Cover, T. Temesvari, T. Tél, U. Frisch, V. N. Vapnik, W. Krauth, Y. Y. Goldschmidt   +31 more
core   +2 more sources