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Fractal and Fractional, Volume 9, Issue 4

2025 April - 70 articles

Cover Story: In this work, we first study the uniqueness, existence, and stability of a new fractional nonlinear partial integro-differential equation in ℝn with three-point conditions and variable coefficients in a Banach space using inverse operators containing multi-variable functions. We also examine a few popular fixed-point theorems. Examples are presented to demonstrate the effectiveness of computing approximate values of generalized Mittag-Leffler functions. We then use the inverse operator method and newly established spaces to find analytic solutions to several partial differential equations, such as a multi-term time-fractional convection problem and a generalized time-fractional diffusion-wave equation, in ℝn with initial conditions only and deduce the uniform solution to the non-homogeneous wave equation in n dimensions. View this paper
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Articles (70)

  • Article
  • Open Access
7 Citations
1,575 Views
23 Pages

Pore structure plays a critical role in evaluating shale “sweet spots”. Compared to marine shale, lacustrine shale has more diverse lithofacies types and greater heterogeneity in pore structure due to frequently changing environmental con...

(This article belongs to the Special Issue Pore Structure and Fractal Characteristics in Unconventional Oil and Gas Reservoirs)
  • Article
  • Open Access
5 Citations
1,568 Views
20 Pages

The successful exploration and development of shale oil in the clay-rich Gulong shale have sparked increased research into the influence of clay minerals on shale reservoirs. However, compared to chlorite in sandstones, limited studies have focused o...

(This article belongs to the Special Issue Pore Structure and Fractal Characteristics in Unconventional Oil and Gas Reservoirs)
  • Article
  • Open Access
3 Citations
2,082 Views
16 Pages

A Simple Fractional Model with Unusual Dynamics in the Derivative Order

  • Guillermo Fernández-Anaya,
  • Francisco A. Godínez,
  • Rogelio Valdés,
  • Luis Alberto Quezada-Téllez and
  • M. A. Polo-Labarrios

Fractional variable order systems with unusual dynamics in the order are a little-studied topic. In this study, we present three examples of very simple fractional systems with unusual dynamics in the derivative order. These cases involve different a...

(This article belongs to the Special Issue Applications of Fractional Calculus in Modern Mathematical Modeling)
  • Article
  • Open Access
1 Citations
1,385 Views
30 Pages

The pore structure of reservoir rocks was a crucial factor affecting hydrocarbon production. Accurately characterized the micropore structure of different types of rock reservoirs was of great significance for unconventional natural gas exploration....

(This article belongs to the Special Issue Pore Structure and Fractal Characteristics in Unconventional Oil and Gas Reservoirs)
  • Article
  • Open Access
2 Citations
1,086 Views
27 Pages

High-tech industries are of strategic importance to the national economy, and Beijing has been designated as a science and technology innovation center by the State Council. Accurate analysis of its added value is crucial for technological developmen...

(This article belongs to the Special Issue Applications of Fractional-Order Grey Models)
  • Article
  • Open Access
2 Citations
1,205 Views
15 Pages

In this article, we study a fractional lower-order differential equation, −D0+αΥ(ξ)+a(ξ)Υ(ξ)=y(ξ),ξ∈(0,1),α∈(1,2), with a Dirichlet-type boundary condition, where a(ξ)∈L1[0,1] permits...

(This article belongs to the Special Issue Advances in Boundary Value Problems for Fractional Differential Equations, 3rd Edition)
  • Article
  • Open Access
7 Citations
2,352 Views
34 Pages

A Comparative Analysis of Different Fractional Optimal Control Strategies to Eradicate Bayoud Disease in Date Palm Trees

  • Muhammad Imran,
  • Azhar Iqbal Kashif Butt,
  • Brett Allen McKinney,
  • Muneerah Al Nuwairan,
  • Fatemah H. H. Al Mukahal and
  • Saira Batool

Bayoud disease, caused by Fusarium oxysporum f. sp. albedinis, is a major threat to date palm trees. It leads to lower crop yields, financial losses, and decreased biodiversity. The complexity of the disease presents challenges to effective disease m...

  • Article
  • Open Access
1 Citations
1,653 Views
16 Pages

In this research article, we investigate a three-dimensional dynamical system governed by fractal-fractional-order evolution differential equations subject to terminal boundary conditions. We derive existence and uniqueness results using Schaefer&rsq...

(This article belongs to the Special Issue Boundary Value Problems for Nonlinear Fractional Differential Equations: Theory, Methods and Application)
  • Article
  • Open Access
10 Citations
2,439 Views
12 Pages

This paper presents an advanced simulation-based investigation of tumor growth and chemical diffusion in biological tissues, using ϑ-fractional stochastic integral equations. Based on the theoretical framework developed in [Fractal Fract. 20...

(This article belongs to the Special Issue Fractal and Fractional Analysis in Biomedical Sciences and Engineering)
  • Article
  • Open Access
5 Citations
1,635 Views
28 Pages

Fractal Analysis of Organic Matter Nanopore Structure in Tectonically Deformed Shales

  • Mingliang Liang,
  • Min Dong,
  • Zongxiu Wang,
  • Kaixun Zhang,
  • Xiaoshi Li and
  • Xingqiang Feng

Fractal analysis was used to characterize the organic matter nanopore structure in tectonically deformed shales, providing insights into the heterogeneity and complexity of the pore network. Shale samples from different tectonic deformation styles (u...

(This article belongs to the Special Issue Pore Structure and Fractal Characteristics in Unconventional Oil and Gas Reservoirs)
  • Article
  • Open Access
1 Citations
1,802 Views
20 Pages

New Fractional Integral Inequalities Involving the Fox-H and Meijer-G Functions for Convex and Synchronous Functions

  • Asifa Tassaddiq,
  • Carlo Cattani,
  • Rabab Alharbi,
  • Dalal Khalid Almutairi and
  • Ruhaila Md Kasmani

On the one hand, convex functions are important to derive rigorous convergence rates, and on the other, synchronous functions are significant to solve statistical problems using Chebyshev inequalities. Therefore, fractional integral inequalities invo...

(This article belongs to the Special Issue Contemporary Methods of Fractional Order Differential and Differential-Operator Equations)
  • Article
  • Open Access
1 Citations
898 Views
31 Pages

A total of 108 maximum Kolmogorov entropy (SK) values, calculated by means of chaos theory, are obtained from 108 time series (TSs) (each consisting of 28,463 hourly data points). The total TSs are divided into 54 urban meteorological (temperature (T...

  • Article
  • Open Access
10 Citations
1,354 Views
24 Pages

Concrete materials exposed to sulfate-rich geological environments are prone to structural durability degradation due to chemical erosion. Silane-based protective materials can enhance the durability of concrete structures under harsh environmental c...

(This article belongs to the Special Issue Fractal and Fractional in Construction Materials)
  • Article
  • Open Access
5 Citations
2,590 Views
20 Pages

This paper proposes an innovative method that combines the homotopy analysis method with the Jafari transform, applying it for the first time to solve systems of fractional-order linear and nonlinear differential equations. The method constructs appr...

  • Article
  • Open Access
8 Citations
1,913 Views
20 Pages

In this paper, a counter-example based on a realistic initial condition invalidates the usual approach related to the so-called physical initial condition of the Caputo derivative used to solve fractional-order Cauchy problems. Due to Infinite State...

  • Article
  • Open Access
9 Citations
3,003 Views
30 Pages

Theoretical and Numerical Analysis of the SIR Model and Its Symmetric Cases with Power Caputo Fractional Derivative

  • Mohamed S. Algolam,
  • Mohammed Almalahi,
  • Khaled Aldwoah,
  • Amira S. Awaad,
  • Muntasir Suhail,
  • Fahdah Ayed Alshammari and
  • Bakri Younis

This paper introduces a novel fractional Susceptible-Infected-Recovered (SIR) model that incorporates a power Caputo fractional derivative (PCFD) and a density-dependent recovery rate. This enhances the model’s ability to capture memory effects and r...

(This article belongs to the Special Issue Advances in Fractional Differential Operators and Their Applications, 2nd Edition)
  • Article
  • Open Access
10 Citations
1,730 Views
20 Pages

Fractal Characterization of a Multi-Scale Pore Structure in Ultra-Deep Coal Seams

  • Yanwei Qu,
  • Feng Chen,
  • Lulu Ma,
  • Peiwen Jiang,
  • Bing Li,
  • Jiangang Ren,
  • Runsheng Lv,
  • Gaofeng Liu,
  • Zhimin Song and
  • George Barakos
  • + 1 author

The pore–fracture structure of ultra-deep coal is critical for evaluating resource potential and guiding the exploration and development of deep coalbed methane (CBM). In this study, a coal sample was obtained from the Gaogu-4 well at a depth o...

(This article belongs to the Special Issue Fractal Analysis and Its Applications in Rock Engineering)
  • Article
  • Open Access
2 Citations
1,740 Views
20 Pages

This paper investigates the well-posedness of analytical solutions to fractional quadratic differential equations, which involve generalized fractional integrals with respect to other functions. The nonlinear components f and h depend on spatial vari...

  • Article
  • Open Access
1 Citations
1,831 Views
41 Pages

Multiple-stream deep learning (DL) models are typically used for multiple-modality datasets, with each model extracting favorable features from its own modality dataset. Through feature fusion, multiple-stream models can generally achieve higher reco...

(This article belongs to the Special Issue Fractal Dimensions with Applications in the Real World)
  • Article
  • Open Access
2 Citations
1,834 Views
15 Pages

This article presents a computational analysis of approximate solutions for the time-fractional nonlinear Kawahara problem (KP) and the modified Kawahara problem (modified KP). This study utilizes the natural homotopy transform scheme (NHTS), which i...

(This article belongs to the Special Issue Numerical and Exact Methods for Nonlinear Differential Equations and Applications in Physics, 2nd Edition)
  • Article
  • Open Access
4 Citations
1,204 Views
19 Pages

In this work, the novel general formula for a time-dependent nuclear reactor system of equations with delayed neutron effect has been formulated using a fractional calculus model. We explore the properties of this model, including two analytical appr...

(This article belongs to the Special Issue Advances in Fractional Modeling and Computation)
  • Article
  • Open Access
3 Citations
1,228 Views
52 Pages

This study focuses on a novel parameterized Wigner distribution, which is an organic integration of the free metaplectic Wigner distribution and the K-Wigner distribution. We style this as the free metaplectic K-Wigner distribution (FMKWD) and invest...

(This article belongs to the Section General Mathematics, Analysis)
  • Article
  • Open Access
2 Citations
1,224 Views
21 Pages

Mechanism Modeling and Analysis of Fractional-Order Synchronous Generator

  • Junhua Xu,
  • Zheng Gong,
  • Xiaocong Li,
  • Songqin Tang,
  • Chunwei Wang and
  • Yue Lan

This paper investigates the fractional-order characteristics of the stator and rotor windings of a synchronous generator. Utilizing mechanism-based modeling methodology, it pioneers the derivation of the fractional-order voltage equations for a synch...

  • Article
  • Open Access
972 Views
14 Pages

This research examines a fractional partial advection–dispersion model, incorporating both mobile and immobile components, employing the Hilbert reproducing algorithm under an appropriate Neumann constraint condition. To effectively formulate t...

(This article belongs to the Special Issue Advances in Fractional Order Derivatives and Their Applications, 3rd Edition)
  • Article
  • Open Access
7 Citations
1,373 Views
16 Pages

With the rapid expansion of the internet and accelerated information dissemination, rumors pose a significant threat to social stability. Effective rumor control requires a thorough understanding of propagation mechanisms. This study develops a Caput...

(This article belongs to the Special Issue Bifurcation, Chaos, and Fractals in Fractional-Order Electrical and Electronic Systems)
  • Article
  • Open Access
2 Citations
1,431 Views
17 Pages

Finite-time synchronization depends on the initial conditions of the system in question. However, the initial conditions of an actual system are often difficult to estimate or even unknown. Therefore, a more valuable and pressing problem is fixed-tim...

(This article belongs to the Special Issue Modeling, Optimization, and Control of Fractional-Order Neural Networks and Nonlinear Systems)
  • Article
  • Open Access
1,292 Views
13 Pages

The static shift effect is a distortion in electromagnetic data that severely impacts exploration results. Traditional static effect correction methods are often ineffective, prone to overcorrection or undercorrection, and make it difficult to accura...

(This article belongs to the Section Complexity)
  • Article
  • Open Access
3 Citations
1,182 Views
24 Pages

In this paper, the authors consider a problem with comprehensive properties in terms of form and content in the space L2a,b×c,d×C0,T,T<1. In terms of time form, we assume that the time phase delay is implicitly contained in a nonlinear...

(This article belongs to the Special Issue Fractional Differential Equations: Computation and Modelling with Applications)
  • Article
  • Open Access
2 Citations
1,435 Views
21 Pages

The stability of differential equations is one of the most important aspects to consider in dynamical system theory. Chaotic systems were classified according to stability as multi-stable systems; systems with a single stable equilibrium; bi-stable s...

  • Article
  • Open Access
5 Citations
1,954 Views
24 Pages

Taylor expansion is a remarkable tool with broad applications in analysis, science, engineering, and mathematics. In this manuscript, we derive a proof of generalized Taylor expansion for polynomials and write its particular case in symmetric quantum...

  • Article
  • Open Access
1 Citations
1,338 Views
22 Pages

The long-term effects of dry–wet cycles induced by seasonal rainfall significantly influence the creep behavior of sliding zone soft rocks, contributing to landslide occurrence. Understanding this aspect is crucial for predicting and mitigating...

(This article belongs to the Section Engineering)
  • Article
  • Open Access
29 Citations
2,619 Views
22 Pages

This paper first examines the evolution of pore-size distribution (PSD) in four types of reconstituted clays during one-dimensional (1D) compression, utilising mercury intrusion porosimetry. Central to this work, fractal theory is then applied to qua...

(This article belongs to the Section Engineering)
  • Article
  • Open Access
7 Citations
2,641 Views
24 Pages

Design, Tuning, and Experimental Validation of Switched Fractional-Order PID Controllers for an Inverted Pendulum System

  • Matias Fernández-Jorquera,
  • Marco Zepeda-Rabanal,
  • Norelys Aguila-Camacho and
  • Lisbel Bárzaga-Martell

Stabilizing inverted pendulum systems remains a challenging and open control problem due to their inherent instability and relevance in a wide range of real-world applications, including robotics and aerospace systems. While PID and fractional-order...

(This article belongs to the Special Issue Fractional Control Systems and Estimation: Control, State Observers and Parameter Estimation)
  • Article
  • Open Access
1 Citations
1,699 Views
18 Pages

With the increasing construction of engineering structures on soft soils, accurately assessing their consolidation behavior has become crucial. To address this, Terzaghi’s one-dimensional consolidation model was revisited. The elastic behavior...

(This article belongs to the Section Engineering)
  • Article
  • Open Access
4 Citations
1,047 Views
16 Pages

In order to explore the influence of grain size on the mechanical properties of unbolted and bolted composite rock masses, uniaxial compression tests were carried out on unbolted and bolted composite rock masses of different grain sizes. The characte...

(This article belongs to the Special Issue Applications of Fractal Analysis in Underground Engineering)
  • Article
  • Open Access
6 Citations
1,586 Views
13 Pages

The first step in investigating fractional difference maps, which do not have periodic points except fixed points, is to find asymptotically periodic and bifurcation points and draw asymptotic bifurcation diagrams. Recently derived equations that all...

  • Article
  • Open Access
11 Citations
2,180 Views
22 Pages

The current research study presents a comprehensive analysis of the local discontinuous Galerkin (LDG) method for solving multi-order fractional differential equations (FDEs), with an emphasis on circuit modeling applications. We investigated the exi...

  • Article
  • Open Access
5 Citations
1,298 Views
21 Pages

We discuss the existence criteria and Ulam–Hyers stability for solutions to a nonlocal integral boundary value problem of nonlinear coupled Hilfer–Hadamard-type fractional Langevin equations. Our results rely on the Leray–Schauder a...

(This article belongs to the Special Issue Advances in Fractional Initial and Boundary Value Problems)
  • Article
  • Open Access
4 Citations
1,400 Views
24 Pages

Significant new progress has been made in nonlinear integrable systems with Riesz fractional-order derivative, and it is impressive that such nonlocal fractional-order integrable systems exhibit inverse scattering integrability. The focus of this art...

(This article belongs to the Special Issue Numerical and Exact Methods for Nonlinear Differential Equations and Applications in Physics, 2nd Edition)
  • Article
  • Open Access
1,077 Views
11 Pages

This work investigates the fractional Dirac system that has transmission conditions, and its boundary condition contains an eigenparameter. Defining a convenient inner product space and a new operator that has the same eigenvalues as the considered p...

(This article belongs to the Special Issue Advances in Fractional Initial and Boundary Value Problems)
  • Article
  • Open Access
9 Citations
4,021 Views
30 Pages

Enhanced Numerical Solutions for Fractional PDEs Using Monte Carlo PINNs Coupled with Cuckoo Search Optimization

  • Tauqeer Ahmad,
  • Muhammad Sulaiman,
  • David Bassir,
  • Fahad Sameer Alshammari and
  • Ghaylen Laouini

In this study, we introduce an innovative approach for addressing fractional partial differential equations (fPDEs) by combining Monte Carlo-based physics-informed neural networks (PINNs) with the cuckoo search (CS) optimization algorithm, termed PIN...

(This article belongs to the Special Issue Advanced Numerical Methods for Fractional Functional Models)
  • Article
  • Open Access
4 Citations
1,666 Views
17 Pages

High-Performance Identification and Control of MIMO (Multiple Input—Multiple Output) Experimental Module with Fractional-Order Approach Application

  • Alexandre Marques de Almeida,
  • Alisson Luan Daga,
  • Rafael Palma Setti Penteado Lanzarini,
  • Ervin Kaminski Lenzi and
  • Marcelo Kaminski Lenzi

This paper focuses on the application of fractional calculus techniques in the identification and control of multivariable (multiple input—multiple output) systems (MIMO). By considering a previously reported experimental set-up similar to a gr...

(This article belongs to the Special Issue Analysis and Applications of Fractional Calculus and Mathematical Modelling)
  • Article
  • Open Access
10 Citations
1,726 Views
23 Pages

In the Southeastern Ordos Basin, the Chang 2 low-permeability sandstone reservoir of the Triassic Yanchang Formation is a typical heterogeneous reservoir. Quantitatively characterizing and analyzing its complex pore throat structure has become crucia...

  • Review
  • Open Access
6 Citations
1,738 Views
17 Pages

Research Status and the Prospect of Fractal Characteristics of Soil Microstructures

  • Jiandong Li,
  • Shengjie Jia,
  • Xu Wang,
  • Yanjie Zhang and
  • Deren Liu

The fractal characteristics of soil microstructures, including the size, distribution, and dynamic evolution process of soil particles, cracks, and intergranular pores, are important factors influencing the macroscopic physical properties of soils. Q...

(This article belongs to the Special Issue Fractal Analysis and Its Applications in Rock Engineering)
  • Article
  • Open Access
3 Citations
1,471 Views
21 Pages

To effectively mitigate resonance in dual-inertia servo inverter systems with a lightweight flexible shaft or coupling, the precise modeling of the dual-mass mechanism is essential. This paper proposes a fractional-order modeling and identification m...

(This article belongs to the Section Engineering)
  • Article
  • Open Access
5 Citations
1,721 Views
18 Pages

Uniaxial compression tests were conducted on coal samples subjected to different dry–wet cycling treatments to investigate the damage and degradation mechanisms of coal samples under the dry–wet cyclic action of acidic, high-salinity solu...

(This article belongs to the Special Issue Fractal Analysis and Its Applications in Rock Engineering, Second Edition)
  • Article
  • Open Access
4 Citations
1,440 Views
30 Pages

Based on the uniaxial compression tests and in situ CT scanning experiments of lignite with different dehydration times and the fractal theory, this paper qualitatively and quantitatively investigated the influence of the dehydration effect on the ev...

(This article belongs to the Special Issue Applications of General Fractional Calculus Models: Insights into Viscoelasticity and Wave Propagation)
  • Article
  • Open Access
1 Citations
1,365 Views
17 Pages

Analysis of Large Membrane Vibrations Using Fractional Calculus

  • Nihar Ranjan Mallick,
  • Snehashish Chakraverty and
  • Rajarama Mohan Jena

The study of vibration equations of large membranes is crucial in various scientific and engineering fields. Analyzing the vibration equations of bridges, roofs, and spacecraft structures helps in designing structures that resist excessive oscillatio...

(This article belongs to the Special Issue Fractional Differential Equations: Computation and Modelling with Applications)
  • Article
  • Open Access
1 Citations
1,171 Views
21 Pages

This work integrates the fast Alikhanov method with a compact scheme to solve the time-fractional Kuramoto–Sivashinsky (KS) equation with the generalized Burgers’ type nonlinearity. Initially, the Alikhanov algorithm, designed to handle t...

(This article belongs to the Special Issue Numerical Solution and Applications of Fractional Differential Equations, 2nd Edition)
  • Article
  • Open Access
1 Citations
1,427 Views
23 Pages

Against the backdrop of increasingly severe global climate challenges, various industries are in urgent need of developing materials that can both improve performance and reduce carbon emissions. In this study, carbon dioxide nanobubble water (CO2NBW...

(This article belongs to the Special Issue Applications of General Fractional Calculus Models: Insights into Viscoelasticity and Wave Propagation)

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Fractal Fract. - ISSN 2504-3110