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In this paper, we consider the approximate controllability of partial differential equations with time derivatives of non-integer order via boundary control. We first show the unique existence of the solution under smooth boundary…

Optimization and Control · Mathematics 2015-01-07 Kenichi Fujishiro

In this paper, some initial-boundary-value problems for the time-fractional diffusion equation are first considered in open bounded n-dimensional domains. In particular, the maximum principle well-known for the PDEs of elliptic and…

Analysis of PDEs · Mathematics 2012-05-08 Yuri Luchko

An initial-boundary value problem for a subdiffusion equation with an elliptic operator $A(D)$ in $\mathbb{R}^N$ is considered. The existence and uniqueness theorems for a solution of this problem are proved by the Fourier method.…

Analysis of PDEs · Mathematics 2020-09-25 A. R. Ashurov , R. T. Zunnunov

In this paper, a sub-optimal boundary control strategy for a free boundary problem is investigated. The model is described by a non-smooth convection-diffusion equation. The control problem is addressed by an instantaneous strategy based on…

Optimization and Control · Mathematics 2020-11-06 Youness Mezzan , Moulay Hicham Tber

We develop a fast divided-and-conquer indirect collocation method for the homogeneous Dirichlet boundary value problem of variable-order space-fractional diffusion equations. Due to the impact of the space-dependent variable order, the…

Numerical Analysis · Mathematics 2019-07-09 Jinhong Jia , Xiangcheng Zheng , Hong Wang

In contrast with the diffusion equation which smoothens the initial data to $C^\infty$ for $t>0$ (away from the corners/edges of the domain), the subdiffusion equation only exhibits limited spatial regularity. As a result, one generally…

Numerical Analysis · Mathematics 2023-07-17 Buyang Li , Zongze Yang , Zhi Zhou

This work presents the design of nonlinear stabilization techniques for the finite element discretization of Euler equations in both steady and transient form. Implicit time integration is used in the case of the transient form. A…

Numerical Analysis · Mathematics 2020-08-26 Santiago Badia , Jesús Bonilla , Sibusiso Mabuza , John N. Shadid

We consider the Schrodinger equation with a logarithmic nonlinearity and a repulsive harmonic potential. Depending on the parameters of the equation, the solution may or may not be dispersive. When dispersion occurs, it does with an…

Numerical Analysis · Mathematics 2023-12-04 Remi Carles , Chunmei Su

This paper deals with numerical solutions to a partial differential equation of fractional order. Generally this type of equation describes a transition from anomalous diffusion to transport processes. From a phenomenological point of view,…

Numerical Analysis · Mathematics 2007-05-23 Mariusz Ciesielski , Jacek Leszczynski

This paper addresses the non-homogeneous Neumann boundary condition on domains with curved boundaries. We consider the Raviart-Thomas element (RTk ) of degree $k \geq 1 $on triangular mesh. on a triangular mesh. A key feature of our…

Numerical Analysis · Mathematics 2024-10-02 Yongli Hou , Yi Liu , Tengjin Zhao

We consider a class of reaction-diffusion equations with a stochastic perturbation on the boundary. We show that in the limit of fast diffusion, one can rigorously approximate solutions of the system of PDEs with stochastic Neumann boundary…

Analysis of PDEs · Mathematics 2014-08-13 Wael W. Mohammed , Dirk Blömker

An unsteady problem is considered for a space-fractional diffusion equation in a bounded domain. A first-order evolutionary equation containing a fractional power of an elliptic operator of second order is studied for general boundary…

Numerical Analysis · Computer Science 2014-12-19 Petr N. Vabishchevich

This paper presents boundary observer design for space and time dependent reaction-advection-diffusion equations using backstepping method. The method uses only a single measurement at the boundary of the systems. The existence of the…

Analysis of PDEs · Mathematics 2017-09-19 Agus Hasan

For the numerical solution of Dirichlet-type boundary value problems associated to nonlinear fractional differential equations of order $\alpha \in (1,2)$ that use Caputo derivatives, we suggest to employ shooting methods. In particular, we…

Numerical Analysis · Mathematics 2025-07-08 Kai Diethelm

The aim of this paper is to find the numerical solutions of the second order linear and nonlinear differential equations with Dirichlet, Neumann and Robin boundary conditions. We use the Bernoulli polynomials as linear combination to the…

Numerical Analysis · Computer Science 2023-05-31 Md. Shafiqul Islam , Afroza Shirin

There has been considerable recent study in "sub-diffusion" models that replace the standard parabolic equation model by a one with a fractional derivative in the time variable. There are many ways to look at this newer approach and one…

Analysis of PDEs · Mathematics 2019-04-08 William Rundell , Zhidong Zhang

We present a second-order algorithm for approximating solutions to nonlocal diffusive processes in reaction-diffusion equations. The numerical scheme relies on a quadrature method for the spatial discretization and a second-order…

Numerical Analysis · Mathematics 2025-12-24 Loic Cappanera , Gabriela Jaramillo

This paper presents an event-triggered boundary control strategy for a class of reaction-diffusion PDEs with time-varying reactivity under Robin actuation. The control approach consists of a backstepping full-state feedback boundary…

Systems and Control · Electrical Eng. & Systems 2023-04-27 Bhathiya Rathnayake , Mamadou Diagne

We consider systems of reaction-diffusion equations coupled in zero order terms, with general homogeneous boundary conditions in domains with a particular geometry (annular type domains). We establish Lipschitz stability estimates in L^2…

Analysis of PDEs · Mathematics 2024-07-02 Catalin-George Lefter , Elena-Alexandra Melnig

We develop an immersed-boundary approach to modeling reaction-diffusion processes in dispersions of reactive spherical particles, from the diffusion-limited to the reaction-limited setting. We represent each reactive particle with a…

Numerical Analysis · Mathematics 2015-06-16 A. Pal Singh Bhalla , B. E. Griffith , N. A. Patankar , A. Donev