This paper deals with the inertial manifold and the approximate inertialmanifold concepts of the Navier-Stokes equations with nonhomogeneous boundary conditions and inertial algorithm. Furtheremore,we provide the erro...This paper deals with the inertial manifold and the approximate inertialmanifold concepts of the Navier-Stokes equations with nonhomogeneous boundary conditions and inertial algorithm. Furtheremore,we provide the error estimates of the approximate solutions of the Navier-Stokes Equations.展开更多
The nonoverlapping domain decomposition method for parabolic partialdifferential equation on general domain is considered. A kind of domain decompositionthat uses the finite element procedure is given. The problem ove...The nonoverlapping domain decomposition method for parabolic partialdifferential equation on general domain is considered. A kind of domain decompositionthat uses the finite element procedure is given. The problem over the domains can beimplemented on parallel computer. Convergence analysis is also presented.展开更多
Abstract Two phase,incompressible miscible flow in porous media is governed by a system of nonlinear partial differential equations.The pressure equation,which is elliptic in appearance,is discretized by a standard fi...Abstract Two phase,incompressible miscible flow in porous media is governed by a system of nonlinear partial differential equations.The pressure equation,which is elliptic in appearance,is discretized by a standard five points difference method.The concentration equation is treated by an implicit finite difference method that applies a form of the method of characteristics to the transport terms.A class of biquadratic interpolation is introduced for the method of characteristics.Convergence rate is proved to be O(Δt+h 2).展开更多
A interior point scaling projected reduced Hessian method with combination of nonmonotonic backtracking technique and trust region strategy for nonlinear equality constrained optimization with nonegative constraint on...A interior point scaling projected reduced Hessian method with combination of nonmonotonic backtracking technique and trust region strategy for nonlinear equality constrained optimization with nonegative constraint on variables is proposed. In order to deal with large problems, a pair of trust region subproblems in horizontal and vertical subspaces is used to replace the general full trust region subproblem. The horizontal trust region subproblem in the algorithm is only a general trust region subproblem while the vertical trust region subproblem is defined by a parameter size of the vertical direction subject only to an ellipsoidal constraint. Both trust region strategy and line search technique at each iteration switch to obtaining a backtracking step generated by the two trust region subproblems. By adopting the l 1 penalty function as the merit function, the global convergence and fast local convergence rate of the proposed algorithm are established under some reasonable conditions. A nonmonotonic criterion and the second order correction step are used to overcome Maratos effect and speed up the convergence progress in some ill-conditioned cases. MR Subject Classification 90C30 - 65K05 - 49M40 Keywords trust region method - backtracking step - reduced Hessian - nonmonotonic technique - interior point Supported partially by the National Natural Science Foundation of China (10071050), Science Foundation (02ZA14070) of Shanghai Technical Sciences Committee and Science Foundation (02DK06) of Shanghai Education Committee.展开更多
Consider an AMG for the linear system Au=f. Up to now, only the uniform convergence of two-level AMG is proved for symmetric and positive definite L-matrices with weak diagonal dominance. Using the new form (1), we ex...Consider an AMG for the linear system Au=f. Up to now, only the uniform convergence of two-level AMG is proved for symmetric and positive definite L-matrices with weak diagonal dominance. Using the new form (1), we extend the results in [1] to the case that A is a general symmetric and positive definite matrix with weak diagonal dominance. In the following, we shall use the same notations as in [1].展开更多
The main aim of this paper is to study the convergence properties of a low order mixed finite element for the Stokes problem under anisotropic meshes. We discuss the anisotropic convergence and superconvergence indepe...The main aim of this paper is to study the convergence properties of a low order mixed finite element for the Stokes problem under anisotropic meshes. We discuss the anisotropic convergence and superconvergence independent of the aspect ratio. Without the shape regularity assumption and inverse assumption on the meshes, the optimal error estimates and natural superconvergence at central points are obtained. The global superconvergence for the gradient of the velocity and the pressure is derived with the aid of a suitable postprocessing method. Furthermore, we develop a simple method to obtain the superclose properties which improves the results of the previous works .展开更多
文摘This paper deals with the inertial manifold and the approximate inertialmanifold concepts of the Navier-Stokes equations with nonhomogeneous boundary conditions and inertial algorithm. Furtheremore,we provide the error estimates of the approximate solutions of the Navier-Stokes Equations.
文摘The nonoverlapping domain decomposition method for parabolic partialdifferential equation on general domain is considered. A kind of domain decompositionthat uses the finite element procedure is given. The problem over the domains can beimplemented on parallel computer. Convergence analysis is also presented.
文摘Abstract Two phase,incompressible miscible flow in porous media is governed by a system of nonlinear partial differential equations.The pressure equation,which is elliptic in appearance,is discretized by a standard five points difference method.The concentration equation is treated by an implicit finite difference method that applies a form of the method of characteristics to the transport terms.A class of biquadratic interpolation is introduced for the method of characteristics.Convergence rate is proved to be O(Δt+h 2).
基金Supported partially by the National Natural Science Foundation of China( 1 0 0 71 0 5 0 ) ScienceFoundation ( 0 2 ZA1 4 0 70 ) of Shanghai Technical Sciences Committee and Science Foundation ( 0 2 DK0 6) ofShanghai Education Committee.
文摘A interior point scaling projected reduced Hessian method with combination of nonmonotonic backtracking technique and trust region strategy for nonlinear equality constrained optimization with nonegative constraint on variables is proposed. In order to deal with large problems, a pair of trust region subproblems in horizontal and vertical subspaces is used to replace the general full trust region subproblem. The horizontal trust region subproblem in the algorithm is only a general trust region subproblem while the vertical trust region subproblem is defined by a parameter size of the vertical direction subject only to an ellipsoidal constraint. Both trust region strategy and line search technique at each iteration switch to obtaining a backtracking step generated by the two trust region subproblems. By adopting the l 1 penalty function as the merit function, the global convergence and fast local convergence rate of the proposed algorithm are established under some reasonable conditions. A nonmonotonic criterion and the second order correction step are used to overcome Maratos effect and speed up the convergence progress in some ill-conditioned cases. MR Subject Classification 90C30 - 65K05 - 49M40 Keywords trust region method - backtracking step - reduced Hessian - nonmonotonic technique - interior point Supported partially by the National Natural Science Foundation of China (10071050), Science Foundation (02ZA14070) of Shanghai Technical Sciences Committee and Science Foundation (02DK06) of Shanghai Education Committee.
基金Project supported by the National Natural Science Foundation of China.
文摘Consider an AMG for the linear system Au=f. Up to now, only the uniform convergence of two-level AMG is proved for symmetric and positive definite L-matrices with weak diagonal dominance. Using the new form (1), we extend the results in [1] to the case that A is a general symmetric and positive definite matrix with weak diagonal dominance. In the following, we shall use the same notations as in [1].
基金the National Natural Science Foundation of China under the grant 10771198
文摘The main aim of this paper is to study the convergence properties of a low order mixed finite element for the Stokes problem under anisotropic meshes. We discuss the anisotropic convergence and superconvergence independent of the aspect ratio. Without the shape regularity assumption and inverse assumption on the meshes, the optimal error estimates and natural superconvergence at central points are obtained. The global superconvergence for the gradient of the velocity and the pressure is derived with the aid of a suitable postprocessing method. Furthermore, we develop a simple method to obtain the superclose properties which improves the results of the previous works .
