Seismic modeling is a foundation of geophysical date processing. A multisymplectic pseudospectral method for seismic modeling is presented in this paper. This method takes the multisymplectic structure of the scalar wave equation into account and possesses discrete multisymplectic conservation laws. Numerical experiments demonstrate the remarkable capability of this new method for long-time sim...

In this paper, we give a characterization of the visibility graphs of pseudo-polygons. We first identify some key combinatorial properties of pseudo-polygons, and we then give a set of five necessary conditions based off our identified properties. We then prove that these necessary conditions are also sufficient via a reduction to a characterization of vertex-edge visibility graphs given by O’R...

Human head movement can be looked at, as a rotational dynamics on the space SO(3) with constraints that have to do with the axis of rotation. Typically the axis vector, after a suitable scaling, is assumed to lie in a surface called Donders’ surface. Various descriptions of Donders’ surface are in the literature and in this paper we assume that the surface is described by a quadratic form. We p...

We study a new method in reducing the roundo error in computing derivatives using Chebyshev collocation methods. By using a grid mapping derived by Koslo and Tal-Ezer, and the proper choice of the parameter , the roundo error of the k-th derivative can be reduced from O(N2k) to O((N jln j)k), where is the machine precision and N is the number of collocation points. This drastic reduction of rou...

We study a new method in reducing the roundo error in computing derivatives using Chebyshev collocation methods. By using a grid mapping derived by Koslo and Tal-Ezer, and the proper choice of the parameter , the roundo error of the k-th derivative can be reduced from O(N) to O((N jln j)k), where is the machine precision and N is the number of collocation points. This drastic reduction of round...

Pseudo-Articulatory Representations (PARs) have been proposed and discussed in relation to speech processing with results reported for both synthesis and recognition. PARs are derived from linguistic specifications of articulatory activity which are both abstract and idealized. The abstractions and idealizations permit the linguistic generality to be distinguished from the articulatory reality;...

The recognition and the calculation of all branches of solutions of the nonlinear boundary value problems is difficult obviously. The complexity of this issue goes back to the being nonlinearity of the problem. Regarding this matter, this paper considers steady state reactive transport model which does not have exact closed-form solution and discovers existence of dual or triple solutions in so...

This is the first paper of a series our works on self-similar orbit-averaged Fokker-Planck (OAFP) equation to model distribution function for stars in isotropic dense spherical star clusters. At late stage relaxation evolution clusters, standard stellar dynamics predicts that clusters evolve fashion forming collapsing cores. However, corresponding mathematical model, OAFP equation, has never be...