Results 1 to 10 of about 115,549 (311)
Mathematics, 2019 In this paper, the Cauchy problem of the modified Helmholtz equation (CPMHE) with perturbed wave number is considered. In the sense of Hadamard, this problem is severely ill-posed. The Fourier truncation regularization method is used to solve this Cauchy
Fan Yang, Ping Fan, Xiao-Xiao Li
doaj +3 more sources
Mathematics, 2019 In present paper, we deal with a backward diffusion problem for a time-fractional diffusion problem with a nonlinear source in a strip domain. We all know this nonlinear problem is severely ill-posed, i.e., the solution does not depend continuously on ...
Fan Yang +3 more
doaj +3 more sources
Nonlinear Parabolic Variational Inequalities with Variable Time-Delay in Time Unbounded Domains
Journal of Optimization, Differential Equations and Their Applications, 2023 We research the well-posedness of the problem without initial condition for nonlinear parabolic variational inequalities with variable time-delay. To justify our results, we impose some assumptions on the solution behavior and growth of the data-in as ...
Mykola M. Bokalo +2 more
doaj +1 more source
Generalization of the Fourier problem of temperature waves in half-space
Физика волновых процессов и радиотехнические системы, 2021 The problem of asymptotic fluctuations of temperature and moisture content in a half-space whose boundary is blown by an air flow with a temperature varying according to the harmonic law is solved by the method of complex amplitudes. The material filling
Anatoly M. Afanasyev +1 more
doaj +1 more source
Quantum states of a particle in a box via unilateral Fourier transform [PDF]
Revista Brasileira de Ensino de Física, 2020 The quantum problem of stationary states of a particle in a box is revisited by means of the unilateral Fourier transform. Homogeneous Dirichlet boundary conditions demand a finite Fourier sine transform which is actually the Fourier sine series.
Douglas W. Vieira, Antonio S. de Castro
doaj +1 more source
Solution for the simple harmonic oscillator problem via unilateral Fourier transform
Revista Brasileira de Ensino de Física, 2023 The solution of the simple harmonic oscillator problem is properly determined by means of the unilateral Fourier transform.
Antonio S. de Castro
doaj +1 more source
Nonlinear elliptic p(u)−Laplacian problem with Fourier boundary condition
Cubo, 2020 We study a nonlinear elliptic \(p(u)-\) Laplacian problem with Fourier boundary conditions and \(L^1-\) data. The existence and uniqueness results of entropy solutions are established.
Stanislas Ouaro, Noufou Sawadogo
doaj +1 more source
Fourier approach to homogenization problems [PDF]
ESAIM: Control, Optimisation and Calculus of Variations, 2002 Summary: This article is divided into two chapters. The classical problem of homogenization of elliptic operators with periodically oscillating coefficients is revisited in the first chapter. Following a Fourier approach, we discuss some of the basic issues of the subject: main convergence theorem, Bloch approximation, estimates on second order ...
Conca Rosende, Carlos +1 more
openaire +3 more sources
Luzin’s Problem on Fourier Convergence and Homeomorphisms
Proceedings of the Steklov Institute of Mathematics, 2022 We show that for every continuous function there exists an absolutely continuous homeomorphism of the circle such that the Fourier series of the composition converges uniformly. This resolves a problem set by N. N. Luzin.
Kozma, Gady, Olevskiĭ, Alexander
openaire +3 more sources
OPERATOR METHOD IN THE PROBLEM OF A PLANE ELECTROMAGNETIC WAVE DIFFRACTION BY AN ANNULAR SLOT IN THE PLANE OR BY A RING [PDF]
Radio Physics and Radio Astronomy, 2021 Purpose: The problem of a plane electromagnetic wave diffraction by an annular slot in the perfectly conducting zero thickness plane is considered.
M. E. Kaliberda +2 more
doaj +1 more source