A general local C-m(m greater than or equal to 0) tetrahedral interpolation scheme by polynomials of degree 4m + 1 plus low order rational functions from the given data is proposed. The scheme can have either 4m + 1 o...
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A general local C-m(m greater than or equal to 0) tetrahedral interpolation scheme by polynomials of degree 4m + 1 plus low order rational functions from the given data is proposed. The scheme can have either 4m + 1 order algebraic precision if C-2m data at vertices and C-m data on faces are given or k + E[k/3] + 1 order algebraic precision if C-k (k less than or equal to 2m) data are given at vertices. The resulted interpolant and its partial derivatives of up to order m are polynomials on the boundaries of the tetrahedra.
Focuses on a study which determined the geometry meaning of the maxima of the CDT mathematical subproblem's dual function. Properties of trust region subproblem; Approximation of the CDT feasible region; Relations...
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Focuses on a study which determined the geometry meaning of the maxima of the CDT mathematical subproblem's dual function. Properties of trust region subproblem; Approximation of the CDT feasible region; Relations between the CDT problem and the trust region problem; Illustration of the geometry meaning of the jump parameter.
In triangulated surface meshes, there are often very noticeable size variances (the vertices are distributed unevenly). The presented noise of such surface meshes is therefore composite of vast frequencies. We solve a...
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In triangulated surface meshes, there are often very noticeable size variances (the vertices are distributed unevenly). The presented noise of such surface meshes is therefore composite of vast frequencies. We solve a diffusion partial differential equation numerically for noise removal of arbitrary triangular manifolds using an adaptive time discretization. The proposed approach is simple and is easy to incorporate into any uniform timestep diffusion implementation with significant improvements over evolution results with the uniform timesteps. As an additional alternative to the adaptive discretization in the time direction, we also provide an approach for the choice of an adaptive diffusion tensor in the diffusion equation.
Recent full hydrodynamic simulations of a sonoluminescing bubble interior have shown that the bubble content is compressed to a very dense state during the violent collapse. In this paper, we numerically studied the s...
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Recent full hydrodynamic simulations of a sonoluminescing bubble interior have shown that the bubble content is compressed to a very dense state during the violent collapse. In this paper, we numerically studied the shape stability of a radially oscillating gas bubble by using Hilgenfeldt et al. theoretical model with corrections taking into account the gas density effect. Our results show that gas density variations not only significantly suppress the Rayleigh-Taylor instability, but also enhance the threshold of the parametric instability under sonoluminescence conditions.
An extended semi-definite programming, the SDP with an additional quadratic term in the objective function, is studied. Our generalization is similar to the generalization from linear programming to quadratic programm...
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An extended semi-definite programming, the SDP with an additional quadratic term in the objective function, is studied. Our generalization is similar to the generalization from linear programming to quadratic programming. Optimal conditions for this new class of problems are discussed and a potential reduction algorithm for solving QSDP problems is presented. The convergence properties of this algorithm are also given.
The three-dimensional compressible Navier-Stokes equations are approximated by a fifth order upwind compact and a sixth order symmetrical compact difference relations combined with three-stage Ronge-Kutta method. The ...
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The three-dimensional compressible Navier-Stokes equations are approximated by a fifth order upwind compact and a sixth order symmetrical compact difference relations combined with three-stage Ronge-Kutta method. The computed results are presented for convective Mach numberMc = 0.8 andRe = 200 with initial data which have equal and opposite oblique waves. From the computed results we can see the variation of coherent structures with time integration and full process of instability, formation of A -vortices, double horseshoe vortices and mushroom structures. The large structures break into small and smaller vortex structures. Finally, the movement of small structure becomes dominant, and flow field turns into turbulence. It is noted that production of small vortex structures is combined with turning of symmetrical structures to unsymmetrical ones. It is shown in the present computation that the flow field turns into turbulence directly from initial instability and there is not vortex pairing in process of transition. It means that for large convective Mach number the transition mechanism for compressible mixing layer differs from that in incompressible mixing layer.
Two general local Cm triangular interpolation schemes by rational functions from Cm data are proposed for any nonnegative integer m. The schemes can have either 2m+1 order algebraic precision if the required data are ...
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Two general local Cm triangular interpolation schemes by rational functions from Cm data are proposed for any nonnegative integer m. The schemes can have either 2m+1 order algebraic precision if the required data are given on vertices and edges, or m+E[m/2]+1 or m+1 order algebraic precision if the data are given only at vertices. The orders of the interpolation error are estimated. Examples that show the correctness and effectiveness of the scheme are presented.
Two new integrable differential-difference equations are proposed. By using Hirota's method, 3-soliton solutions of the Kaup-Kupershmidt equation type are obtained with the assistance of Mathematica. Besides, Lax ...
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Two new integrable differential-difference equations are proposed. By using Hirota's method, 3-soliton solutions of the Kaup-Kupershmidt equation type are obtained with the assistance of Mathematica. Besides, Lax pairs of these two lattices are also presented. (C) 2000 Published by Elsevier Science B.V.
We present an implementation of parallel prestack depth migration for 2-D Marmousi data. Our implementation is based on the three prestack depth migration methods: finite-difference method, split-step Fourier method a...
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ISBN:
(纸本)0769505892
We present an implementation of parallel prestack depth migration for 2-D Marmousi data. Our implementation is based on the three prestack depth migration methods: finite-difference method, split-step Fourier method and Fourier finite-difference method. In this article, a brief description of the three methods is given, and the performance of parallel implementation with Message Passing Interface (MPI) and the migration profiles of Marmousi data are presented. It is shown that the Fourier finite-difference migration produced more accurate images in the areas of large lateral velocity variations.
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