In this paper we present a set of absorbing boundary conditions based on the higher order approximations of one-way wave equations. By introducing new functions, these absorbing boundary conditions are put into the fo...
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In this paper we present a set of absorbing boundary conditions based on the higher order approximations of one-way wave equations. By introducing new functions, these absorbing boundary conditions are put into the form of systems of lower order partial differential equations. The stability of initial boundary value problems with these type of boundary conditions is discussed. The energy estimates for their solutions are obtained.
Do-loop unrolling is an effective technique for improving performance of applicistion programs. This paper presents a method for unrolling nested Fortran DO-loops using the m4 macro language. m4 is a macro processor w...
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Do-loop unrolling is an effective technique for improving performance of applicistion programs. This paper presents a method for unrolling nested Fortran DO-loops using the m4 macro language. m4 is a macro processor widely available on UNIX platforms. By using carefully designed m4 macros, Do-loop unrolling becomes much simpler. More over, with this method, code can be written for general ullrolling parameters, allowing the program to be easily tuned bn different computers to reach optimal performance.
In this paper we have studied the mixed finite element method for the non stationary conduct ic n-convection problems, where the coupled equations governing viscous incompressible flow and heat transfer process, and i...
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In this paper we have studied the mixed finite element method for the non stationary conduct ic n-convection problems, where the coupled equations governing viscous incompressible flow and heat transfer process, and incompressible fluid are the Boussinesq approximations to the nonstationary Navier-Stokes *** have discussed the existence of continuous, semi-discrete and fully discrete solutions, and derive the error estimates for the approximate solutions on the continuous and discrete time cases.
Asynchronous parallel multisplitting nonlinear symmetric Gauss-Seidel methods are established for the system of nonlinear equations , withA, B∈L(Rn) being matrices of particular properties, being diagonal and continu...
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Asynchronous parallel multisplitting nonlinear symmetric Gauss-Seidel methods are established for the system of nonlinear equations , withA, B∈L(Rn) being matrices of particular properties, being diagonal and continuous mappings, and b ∈Rn a known vector. The establishments of these new methods are according to the principle of sufficiently using the delayed information and are concerning about the concrete characteristics of the multiprocessor systems. Therefore, they have considerably higher parallel computingefficiency. The global convergenge as well as the asymptotic convergence rates of these new methods are investigated in detail under suitable conditions.
In using the methods given by [1] to compute the hypersingular integrals on interval,one should select the mesh carefully in such a way that singular point falls near the center of a subinterval. A numerical method gi...
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In using the methods given by [1] to compute the hypersingular integrals on interval,one should select the mesh carefully in such a way that singular point falls near the center of a subinterval. A numerical method given in this paper might solve this problem. This new method is very simple, easy to be implemented, and above all, notaffected by the location of singular point.
In this paper the natural boundary reduction, suggested by Feng and Yu[1], is applied to deal with the three-dimensional problems. By expansion in spherical harmonics, we obtain the natural integral equations of harmo...
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In this paper the natural boundary reduction, suggested by Feng and Yu[1], is applied to deal with the three-dimensional problems. By expansion in spherical harmonics, we obtain the natural integral equations of harmonic problems over interior and exterior spherical domains. Meanwhile, we develop a numerical method for sloving these equations. Some numerical examples are also given to illustrate our method.
This paper deals with parallel implemeatation on distributed memory systemsof a pressure-correction projection scheme for the unsteady incompressible NavierStokes equations, the CNMT2 scheme (i.e., the Crank-Nickolson...
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This paper deals with parallel implemeatation on distributed memory systemsof a pressure-correction projection scheme for the unsteady incompressible NavierStokes equations, the CNMT2 scheme (i.e., the Crank-Nickolson Modified Temamscheme Ⅱ), presented in [1, 2]. The key point of this work is to study parallelizationof the fast Poisson solver [2] and analyse its parallel efficiency. Various techniques,such as pipelining and canon cyclic algorithm, were used to ensure good parallel performance and scalability of the algorithm. The algorithm has been implemented using MPI message passing environment and numerical tests have been carried out on various computers, including the home made Dawn-1000 MPP system and workstation clusters.
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