Advances in Differential Equations and Its Applications

A special issue of Axioms (ISSN 2075-1680). This special issue belongs to the section "Mathematical Analysis".

Deadline for manuscript submissions: 31 January 2025 | Viewed by 1027

Special Issue Editors


E-Mail Website
Guest Editor
Faculty of Mathematics and Informatics, University of Plovdiv, 4000 Plovdiv, Bulgaria
Interests: fractional differential equations; functional-differential equations; impulsive differential equations; differential equations in Banach spaces; integral equations; integral inequalities; stability analysis; real and functional analysis; applied mathematics
Special Issues, Collections and Topics in MDPI journals

E-Mail Website
Guest Editor
Faculty of Mathematics and Informatics, University of Plovdiv, 4000 Plovdiv, Bulgaria
Interests: fractional differential equations; impulsive differential equations; functional-differential equations; differential equations in Banach spaces
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

The present Special Issue is devoted to new research in the area of differential equations (or systems) with fractional- or integer-order derivatives without delay or with a delayed argument (of a retarded or neutral type). Works devoted to stochastic differential equations with fractional derivatives are welcome too. The works can focus on aspects of fundamental theory such as initial value problems, boundary value problems, and different kinds of integral representations of the solutions and their continuous dependence on the given data. We also encourage works in the field of the qualitative theory, such as the asymptotic behaviour of solutions with various types of stability properties, namely Lyapunov’s type, finite time stability, Mittag–Leffler stability, robust stability, Ulam–Hyers–Rassias stability, etc. Works which contain results which are general to fractional and integer-based differential equations, as well as those which establish specific results for these classes, are also invited. Furthermore, works containing new models or including fractional variants of well-known classical models in different areas of sciences such as economics, physics, engineering, etc., will be met with increased interest.

We look forward to receiving your contributions.

Prof. Dr. Andrey Zahariev
Prof. Dr. Hristo Kiskinov
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Axioms is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • functional differential equations/systems
  • fractional differential equations/systems
  • fractional derivatives of a constant order
  • distributed-order fractional derivatives
  • variable-order fractional derivatives
  • stability analysis of fractional-order systems
  • asymptotic properties of fractional-order systems

Published Papers (1 paper)

Order results
Result details
Select all
Export citation of selected articles as:

Research

23 pages, 5971 KiB  
Article
Improving Realism of Facial Interpolation and Blendshapes with Analytical Partial Differential Equation-Represented Physics
by Sydney Day, Zhidong Xiao, Ehtzaz Chaudhry, Matthew Hooker, Xiaoqiang Zhu, Jian Chang, Andrés Iglesias, Lihua You and Jianjun Zhang
Axioms 2024, 13(3), 185; https://doi.org/10.3390/axioms13030185 - 12 Mar 2024
Viewed by 850
Abstract
How to create realistic shapes by interpolating two known shapes for facial blendshapes has not been investigated in the existing literature. In this paper, we propose a physics-based mathematical model and its analytical solutions to obtain more realistic facial shape changes. To this [...] Read more.
How to create realistic shapes by interpolating two known shapes for facial blendshapes has not been investigated in the existing literature. In this paper, we propose a physics-based mathematical model and its analytical solutions to obtain more realistic facial shape changes. To this end, we first introduce the internal force of elastic beam bending into the equation of motion and integrate it with the constraints of two known shapes to develop the physics-based mathematical model represented with dynamic partial differential equations (PDEs). Second, we propose a unified mathematical expression of the external force represented with linear and various nonlinear time-dependent Fourier series, introduce it into the mathematical model to create linear and various nonlinear dynamic deformations of the curves defining a human face model, and derive analytical solutions of the mathematical model. Third, we evaluate the realism of the obtained analytical solutions in interpolating two known shapes to create new shape changes by comparing the shape changes calculated with the obtained analytical solutions and geometric linear interpolation to the ground-truth shape changes and conclude that among linear and various nonlinear PDE-based analytical solutions named as linear, quadratic, and cubic PDE-based interpolation, quadratic PDE-based interpolation creates the most realistic shape changes, which are more realistic than those obtained with the geometric linear interpolation. Finally, we use the quadratic PDE-based interpolation to develop a facial blendshape method and demonstrate that the proposed approach is more efficient than numerical physics-based facial blendshapes. Full article
(This article belongs to the Special Issue Advances in Differential Equations and Its Applications)
Show Figures

Figure 1

Back to TopTop