18 research outputs found
Identification of the unknown diffusion coefficient in a linear parabolic equation via semigroup approach
Determination of the unknown boundary condition of the inverse parabolic problems via semigroup method
An Application of Semigroup Method in a Parabolic Equation with Mixed Boundary Conditions
Identification of the unknown coefficient in a quasi-linear parabolic equation by a semigroup approach
An Inverse Source Problem in Time-Space Fractional Differential Equations
In this paper we study a one dimensional inverse source problem. Distinguishability according to the source function in time-space fractional equation Db t u(x, t) = D2a x u(x, t)+ f (x), 1
Inverse Problem for a Time Fractional Parabolic Equation with Nonlocal Boundary Conditions
This article considers an inverse problem of time fractional parabolic partial differential equations with the nonlocal boundary condition. Dirichlet-measured output data are used to distinguish the unknown coefficient. A finite difference scheme is constructed and a numerical approximation is made. Examples and numerical experiments, such as man-made noise, are provided to show the stability and efficiency of this numerical method
A mathematical model and numerical solution of interface problems for steady state heat conduction
We study interface (or transmission) problems arising in
the steady state heat conduction for layered medium. These problems are related to the
elliptic equation of the form Au:=ââ(k(x)âu(x))=F(x), xâΩââ2, with discontinuous coefficient k=k(x). We analyse two types of jump (or contact)
conditions across the interfaces ÎÎŽâ=Ω1â©Î©ÎŽ and ÎÎŽ+=ΩΎâ©Î©2 of the layered medium
Ω:=Ω1âȘΩΎâȘΩ2. An asymptotic analysis of the
interface problem is derived for the case when the thickness (2ÎŽ>0) of the layer
(isolation) ΩΎ tends to zero. For each case, the local truncation errors of
the used conservative finite difference scheme are estimated on the nonuniform grid.
A fast direct solver has been applied for the interface problems with piecewise constant but
discontinuous coefficient k=k(x). The presented numerical results illustrate high
accuracy and show applicability of the given approach
On Fractional Newton-Type Method for Nonlinear Problems
The current manuscript is concerned with the development of the NewtonâRaphson method, playing a significant role in mathematics and various other disciplines such as optimization, by using fractional derivatives and fractional Taylor series expansion. The development and modification of the NewtonâRaphson method allow us to establish two new methods, which are called first- and second-order fractional NewtonâRaphson (FNR) methods. We provide convergence analysis of first- and second-order fractional methods and give a general condition for the convergence of higher-order FNR. Finally, some illustrative examples are considered to confirm the accuracy and effectiveness of both methods
Inverse Problem for a Time Fractional Parabolic Equation with Nonlocal Boundary Conditions
This article considers an inverse problem of time fractional parabolic partial differential equations with the nonlocal boundary condition. Dirichlet-measured output data are used to distinguish the unknown coefficient. A finite difference scheme is constructed and a numerical approximation is made. Examples and numerical experiments, such as man-made noise, are provided to show the stability and efficiency of this numerical method