This paper considers the regularity of solutions to mixed boundary value problems in small-angle regions for elliptic equations. By constructing a specific barrier function, we proved that under the assumption of suff...This paper considers the regularity of solutions to mixed boundary value problems in small-angle regions for elliptic equations. By constructing a specific barrier function, we proved that under the assumption of sufficient regularity of boundary conditions and coefficients, as long as the angle is sufficiently small, the regularity of the solution to the mixed boundary value problem of the second-order elliptic equation can reach any order.展开更多
A dynamical system for computing the elliptic boundary problem is presented.It is shown that the proposed system is globally asymptotically stable.The system can be simulated by a neural network.Simulation results are...A dynamical system for computing the elliptic boundary problem is presented.It is shown that the proposed system is globally asymptotically stable.The system can be simulated by a neural network.Simulation results are valid and satisfactory.展开更多
In this paper we prove a very general result concerning solvability of the resonant problem: Δu+λ<sub>k</sub>u+g(x, u)=h(x);u=0, xΩ, which immediately gives three generalized Landesman-Lazer conditi...In this paper we prove a very general result concerning solvability of the resonant problem: Δu+λ<sub>k</sub>u+g(x, u)=h(x);u=0, xΩ, which immediately gives three generalized Landesman-Lazer conditions. The most interesting application of the general result is concerned with the problem when λ<sub>k</sub>=λ<sub>1</sub>. in which case we prove solvability results for it under conditions which are not the standard Landesman-Lazer condition or only partly enjoy it. Furthermore, we propose a new sign condition and give a comprehensive extension of a main result of Figueiredo and Ni.展开更多
This paper is devoted to study of an iterative procedure for domain decomposition method of second order elliptic problem with mixed boundary conditions (i.e., Dirichlet condition on a part of boundary and Neumann con...This paper is devoted to study of an iterative procedure for domain decomposition method of second order elliptic problem with mixed boundary conditions (i.e., Dirichlet condition on a part of boundary and Neumann condition on the another part of boundary). For the pure Dirichlet problem, Marini and Quarteroni [3], [4] considered a similar approach, which is extended to more complex problem in this paper.展开更多
We study profiles of positive solutions for quasilinear elliptic boundary blow-up problems and Dirichlet problems with the same equation:where ω 〉 0, a(x) is a continuous function satisfying 0 〈 a(x) 〈 1 for...We study profiles of positive solutions for quasilinear elliptic boundary blow-up problems and Dirichlet problems with the same equation:where ω 〉 0, a(x) is a continuous function satisfying 0 〈 a(x) 〈 1 for x ∈Ω, Ω is a bounded smooth domain in R^N. We will see that the profile of a minimal positive boundary blow-up solution of the equation shares some similarities to the profile of a positive minimizer solution of the equation with homogeneous Dirichlet boundary condition.展开更多
In this paper, a class of rectangular finite elements for 2m-th-oder elliptic boundary value problems in n-dimension (m, n ≥1) is proposed in a canonical fashion, which includes the (2m - 1)-th Hermite interpolat...In this paper, a class of rectangular finite elements for 2m-th-oder elliptic boundary value problems in n-dimension (m, n ≥1) is proposed in a canonical fashion, which includes the (2m - 1)-th Hermite interpolation element (n = 1), the n-linear finite element (m = 1) and the Adini element (m = 2). A nonconforming triangular finite element for the plate bending problem, with convergent order (O(h2), is also proposed.展开更多
Under simple conditions, we prove the existence of three solutions for a fourth-order asymptotically linear elliptic boundary value problem. For the resonance case at infinity, we do not need to assume any more condit...Under simple conditions, we prove the existence of three solutions for a fourth-order asymptotically linear elliptic boundary value problem. For the resonance case at infinity, we do not need to assume any more conditions to ensure the boundedness of the (PS) sequence of the corresponding functional.展开更多
The existence of positive solutions to the semlinear elliptic boundary value problem-Δ=f(x,u) in n and u= 0 on is studied in this paper. The result obtained differs from the other known results in that the positivity...The existence of positive solutions to the semlinear elliptic boundary value problem-Δ=f(x,u) in n and u= 0 on is studied in this paper. The result obtained differs from the other known results in that the positivity of the solution does not follow from the positivity of f.Our result roughly says that if Ω is not too wide in some one direction, there is always a positive solution even if fchanges signs, which is proved using the so-calles sub-super solution approach.展开更多
One of the main difficulties in the application of the method of fundamental solutions(MFS)is the determination of the position of the pseudo-boundary on which are placed the singularities in terms of which the approx...One of the main difficulties in the application of the method of fundamental solutions(MFS)is the determination of the position of the pseudo-boundary on which are placed the singularities in terms of which the approximation is expressed.In this work,we propose a simple practical algorithm for determining an estimate of the pseudo-boundary which yields the most accurate MFS approximation when the method is applied to certain boundary value problems.Several numerical examples are provided.展开更多
We study galvanic currents on a heterogeneous surface. In electrochemistry, the oxidation-reduction reaction producing the current is commonly modeled by a nonlinear elliptic boundary value problem. The boundary condi...We study galvanic currents on a heterogeneous surface. In electrochemistry, the oxidation-reduction reaction producing the current is commonly modeled by a nonlinear elliptic boundary value problem. The boundary condition is of exponential type with periodically varying parameters. We construct an approximation by first homogenizing the problem, and then linearizing about the homogenized solution. This approximation is far more accurate than both previous approximations or direct linearization. We establish convergence estimates for both the two and three-dimensional case and provide two-dimensional numerical experiments.展开更多
Examines a nonlinear partial differential equation of elliptic type with the homogeneous Dirichlet boundary conditions; Proof of the comparison and maximum principles; Approximation of the finite element; Introduction...Examines a nonlinear partial differential equation of elliptic type with the homogeneous Dirichlet boundary conditions; Proof of the comparison and maximum principles; Approximation of the finite element; Introduction of a discrete analogue of the maximum principle for linear elements.展开更多
Presents preconditioning matrices having parallel computing function for the coefficient matrix and a class of parallel hybrid algebraic multilevel iteration methods for solving linear equations. Solution to elliptic ...Presents preconditioning matrices having parallel computing function for the coefficient matrix and a class of parallel hybrid algebraic multilevel iteration methods for solving linear equations. Solution to elliptic boundary value problem; Discussion on symmetric positive definite matrix; Computational complexities.展开更多
This paper contains a generalization of the well–known Palais–Smale andCerami compactness conditions. The compactness condition introduced is used to prove some generalexistence theorems for critical points. Some ap...This paper contains a generalization of the well–known Palais–Smale andCerami compactness conditions. The compactness condition introduced is used to prove some generalexistence theorems for critical points. Some applications are given to differential equations.展开更多
We examine a steady-state heat radiation problem and its finite element approximation in Rd, d = 2, 3. A nonlinear Stefan-Boltzmann boundary condition is considered. Another nonlinearity is due to the fact that the te...We examine a steady-state heat radiation problem and its finite element approximation in Rd, d = 2, 3. A nonlinear Stefan-Boltzmann boundary condition is considered. Another nonlinearity is due to the fact that the temperature is always greater or equal than 0[K]. We prove two convergence theorems for piecewise linear finite element solutions.展开更多
文摘This paper considers the regularity of solutions to mixed boundary value problems in small-angle regions for elliptic equations. By constructing a specific barrier function, we proved that under the assumption of sufficient regularity of boundary conditions and coefficients, as long as the angle is sufficiently small, the regularity of the solution to the mixed boundary value problem of the second-order elliptic equation can reach any order.
文摘A dynamical system for computing the elliptic boundary problem is presented.It is shown that the proposed system is globally asymptotically stable.The system can be simulated by a neural network.Simulation results are valid and satisfactory.
文摘In this paper we prove a very general result concerning solvability of the resonant problem: Δu+λ<sub>k</sub>u+g(x, u)=h(x);u=0, xΩ, which immediately gives three generalized Landesman-Lazer conditions. The most interesting application of the general result is concerned with the problem when λ<sub>k</sub>=λ<sub>1</sub>. in which case we prove solvability results for it under conditions which are not the standard Landesman-Lazer condition or only partly enjoy it. Furthermore, we propose a new sign condition and give a comprehensive extension of a main result of Figueiredo and Ni.
文摘This paper is devoted to study of an iterative procedure for domain decomposition method of second order elliptic problem with mixed boundary conditions (i.e., Dirichlet condition on a part of boundary and Neumann condition on the another part of boundary). For the pure Dirichlet problem, Marini and Quarteroni [3], [4] considered a similar approach, which is extended to more complex problem in this paper.
基金Supported by National Natural Science Foundation of China (Grant No. 10871060)
文摘We study profiles of positive solutions for quasilinear elliptic boundary blow-up problems and Dirichlet problems with the same equation:where ω 〉 0, a(x) is a continuous function satisfying 0 〈 a(x) 〈 1 for x ∈Ω, Ω is a bounded smooth domain in R^N. We will see that the profile of a minimal positive boundary blow-up solution of the equation shares some similarities to the profile of a positive minimizer solution of the equation with homogeneous Dirichlet boundary condition.
基金The work was supported by the National Natural Science Foundation of China (10871011).
文摘In this paper, a class of rectangular finite elements for 2m-th-oder elliptic boundary value problems in n-dimension (m, n ≥1) is proposed in a canonical fashion, which includes the (2m - 1)-th Hermite interpolation element (n = 1), the n-linear finite element (m = 1) and the Adini element (m = 2). A nonconforming triangular finite element for the plate bending problem, with convergent order (O(h2), is also proposed.
基金the"973"Program of the Chinese National Science Foundationthe Foundation of Chinese Academy of Sciences
文摘Under simple conditions, we prove the existence of three solutions for a fourth-order asymptotically linear elliptic boundary value problem. For the resonance case at infinity, we do not need to assume any more conditions to ensure the boundedness of the (PS) sequence of the corresponding functional.
文摘The existence of positive solutions to the semlinear elliptic boundary value problem-Δ=f(x,u) in n and u= 0 on is studied in this paper. The result obtained differs from the other known results in that the positivity of the solution does not follow from the positivity of f.Our result roughly says that if Ω is not too wide in some one direction, there is always a positive solution even if fchanges signs, which is proved using the so-calles sub-super solution approach.
文摘One of the main difficulties in the application of the method of fundamental solutions(MFS)is the determination of the position of the pseudo-boundary on which are placed the singularities in terms of which the approximation is expressed.In this work,we propose a simple practical algorithm for determining an estimate of the pseudo-boundary which yields the most accurate MFS approximation when the method is applied to certain boundary value problems.Several numerical examples are provided.
基金Acknowledgments. This research is partially supported by the National Science Foundation Grants DMS#0619080 and DMS#0605021.
文摘We study galvanic currents on a heterogeneous surface. In electrochemistry, the oxidation-reduction reaction producing the current is commonly modeled by a nonlinear elliptic boundary value problem. The boundary condition is of exponential type with periodically varying parameters. We construct an approximation by first homogenizing the problem, and then linearizing about the homogenized solution. This approximation is far more accurate than both previous approximations or direct linearization. We establish convergence estimates for both the two and three-dimensional case and provide two-dimensional numerical experiments.
基金This paper was supported by the common Czech-US cooperative research project of the programmeKONTACT No. ME 148 (1998).
文摘Examines a nonlinear partial differential equation of elliptic type with the homogeneous Dirichlet boundary conditions; Proof of the comparison and maximum principles; Approximation of the finite element; Introduction of a discrete analogue of the maximum principle for linear elements.
基金Subsidized by the Special Funds for Major State Basic Research Projects G1999032803 and Suported bythe National Natural Scienc
文摘Presents preconditioning matrices having parallel computing function for the coefficient matrix and a class of parallel hybrid algebraic multilevel iteration methods for solving linear equations. Solution to elliptic boundary value problem; Discussion on symmetric positive definite matrix; Computational complexities.
文摘This paper contains a generalization of the well–known Palais–Smale andCerami compactness conditions. The compactness condition introduced is used to prove some generalexistence theorems for critical points. Some applications are given to differential equations.
文摘We examine a steady-state heat radiation problem and its finite element approximation in Rd, d = 2, 3. A nonlinear Stefan-Boltzmann boundary condition is considered. Another nonlinearity is due to the fact that the temperature is always greater or equal than 0[K]. We prove two convergence theorems for piecewise linear finite element solutions.