Boundary problem

In recent years, the prediction of the effective transport properties have received a great number of investigations. The present work is dedicated to determining the effective permeability of two-dimensional (2D) doubly porous materials made of an isotropic permeable solid matrix in which elliptical shaped pores of any size are embedded.

10p vibecca 01-10-2024 0 0   Download

The "determining modes" concept introduced by Foias and Prodi in 1967 say that if two solutions agree asymptotically in their P projection, then they are asymptotical in their entirety. In this paper, we consider the 2D g-Bénard problem in domains satisfying the Poincaré inequality with homogeneous Dirichlet boundary conditions.

14p vibecca 01-10-2024 1 0   Download

In this report, we examine the unsteady Stokes equations with nonhomogeneous boundary conditions. As an application of a Carleman estimate, we first establish log type stabilities for the solution of the equations from either an interior measurement of the velocity, or a boundary observation depending on the trace of the velocity and of the Cauchy stress tensor measurements on a part of the boundary.

16p vibecca 01-10-2024 2 1   Download

This paper presents an efficient and accurate numerical technique based upon the scaled boundary finite element method for the analysis of two-dimensional, linear, second-order, boundary value problems with the domain completely described by a circular defining curve.

11p vifilm 24-09-2024 3 1   Download

The scaled boundary finite element method (SBFEM) is a semi-analytical method, whose versatility, accuracy, and efficiency are not only equal to, but potentially better than the finite element method and the boundary element method for certain problems. This paper investigates the possibility of using an efficient high-order polynomial element in the SBFEM to form the approximation in the circumferential direction.

14p vifilm 24-09-2024 3 1   Download

The problem of Rayleigh waves in compressible orthotropic elastic half-space overlaid by a thin elastic layer of which principal material axes are coincident have been researched by many scientists. This paper presents a traditional approach to obtain an approximate secular equation by approximately replacing the thin layer by effective boundary conditions of third-order.

11p vifilm 24-09-2024 7 1   Download

In this study, the Ritz variational method is used to analyze and solve the bending problem of rectangular functionally graded material plate with general boundary conditions and subject to some types of load distribution over the entire plate domain. Based on the Kirchoff plate theory, the equilibrium equations are obtained by minimizing the total potential energy.

12p viyoko 24-09-2024 2 1   Download

The objective of the thesis is to develop the iterative method and combining it with other methods to study qualitative and especially the method of solving some two-point boundary problems for the fourth-order differential equations and systems, arising in beam bending theory without using condition of growth rate at infinity, Nagumo condition, etc. of the right-hand side function.

27p capheviahe27 23-02-2021 12 5   Download

The thesis proposes a simple but very effective method to study the unique solvability and an iterative method for solving five boundary value problems for nonlinear fourth order ordinary differential equations with different types of boundary conditions and two boundary value problems for a biharmonic equation and a biharmonic equation of Kirchhoff type by using the reduction of these problems to the operator equations for the function to be sought or an intermediate function.

27p larachdumlanat129 20-01-2021 29 3   Download

In this paper, we consider the initial boundary value problem for Schrodinger systems in the cylinders with base containing the conical point. The existence and the uniqueness of the generanized solution of this problem are given.

8p larachdumlanat127 20-12-2020 15 1   Download

The purpose of this paper is to establish the existence, the uniqueness and regularity with respect to time variable of solution of the boundary value problems without initial condition for Schrodinger systems in cylinders with base containing conical points.

4p tamynhan8 04-11-2020 16 4   Download

The goal of this paper is to establish the unique existence of generalized solutions of boundary problem for second-order parabolic equations without an initial condition in cylinders with non-smooth base.

5p tamynhan8 04-11-2020 8 1   Download

The purpose of this paper is to establish the regularity with respect to time variable of solution of the initial boundary value problems for Schrodinger systems in the cylinders with base containing the conical point.

10p tamynhan8 04-11-2020 12 1   Download

In this paper, we study the first initial boundary value problem for second-order parabolic equations in cylinders with piecewise smooth base. Some results on the unique existence and on the smoothness with respect to time of the solution are given.

12p tamynhan8 04-11-2020 3 1   Download

In this paper, we study the Neumann problem for second order hyperbolic equations without initial data in nonsmooth domains. Our intension was to prove the existence of a generalized solution to this problem by applying the results of this problem to the initial data.

7p tamynhan8 04-11-2020 19 1   Download

The purpose of this paper is to prove the existence of generalized solution of a boundary value problem for the second order hyperbolic equations without initial conditions in nonsmooth domains.

7p tamynhan8 04-11-2020 12 2   Download

In this paper we study the first initial boundary problem for semilinear hyperbolic equations in nonsmooth cylinders, where is a nonsmooth domain in Rn, n >=2. We established the existence and uniqueness of a global solution in time.

11p tamynhan8 04-11-2020 24 1   Download

In this paper, we study the Neumann boundary value problems without initial condition for Hyperbolic systems in cylinders. The main obtained results are the uniqueness and the existence of generalized solutions.

12p tamynhan8 04-11-2020 13 2   Download

We consider the 2D g-B´enard problem in domains satisfying the Poincar´e inequality with homogeneous Dirichlet boundary conditions. We prove the existence and uniqueness of global weak solutions. The obtained results particularly extend previous results for 2D g-Navier-Stokes equations and 2D B´enard problem.

9p koxih_kothogmih5 04-09-2020 16 3   Download

This study develops unconditionally monotone finite-difference scheme of second-order of local approximation on uniform grids for the initial boundary problem value for the Gamma equation through the establishment of two-side estimates for the scheme’s solution.

8p tamynhan6 14-09-2020 17 2   Download