the proposed algorithm with the same truiicafion length in the Viterbi decoder. The results show that the error-correction capability of the proposed algorithm is significantly improved over that of the existing algorithm. When truncation length is set to 25 and channel error is 5%, the existing algorithm cannot correct 0.242% of errors, while the proposed algorithm reduces it to 10.088% These ...

? = 0(r = 0), i^=-F(i), (r=l) dr u dr where Fit) is an empirical function of t. In all cases, as far as the authors are aware, the differential coefficients in (1) are considered separately when replaced by differences, and the principal term in du the truncation error of any difference formula obtained in this way contains — and ö u —Z-. This can be seen by obtaining the time derivatives of u ...

A one dimensional steady-state advection-diffusion problem using summationby-parts operators has been investigated. For approximating the second derivative, a wide stencil has been used, which has spurious, oscillating, modes for all mesh-sizes. We show that the size of the spurious modes are equal to the size of the truncation error for a stable approximation. The theoretical results are verif...

A new kind of finite difference method is presented for solving two point boundary value problems. The method is based on rational function approximation technique and its development and analysis is based on Taylor series and binomial expansions. Local truncation error of the method is discussed. The method is tested on model problems and the numerical results are presented. The numerical resu...

(see [9] and [10]). Throughout this work, we assume that the function satis®es the following conditions: (i) j …x†j …cons:† jB…x†j=jxj1‡"; where " 0 and jB…x†j is bounded and 1-periodic function on R. (ii) P n2Z …n† eÿin converges absolutely to a function that has no zeros on ‰ÿ ; Š. It is known that conditions (i) and (ii) imply that fK…x; n†; n 2 Zg is a Riesz basis on V , with a unique biort...

The velocity potential around two spheres moving perpendicularly to the line joining their centers is given by a series of spherical harmonics. The appropriateness of the truncation is evaluated by determining the residual normal surface velocity on the spheres. In evaluating the residual normal velocity, a recursive procedure is constructed to evaluate the spherical harmonics to reduce computa...

A technique .of initialization for the primitive forecast equations is presented. The method consists of a marching prediction scheme performed in such a manner that the large-scale solution remains approximately steady, and high-frequency modes created in the adjustment process are damped selectively by time differencing with the Eulerbackward method. The scheme places no restriction on the wi...

Ewald summation is an efficient method for computing the periodic sums that appear when considering the Green’s functions of Stokes flow together with periodic boundary conditions. We show how Ewald summation, and accompanying truncation error estimates, can be easily derived for the rotlet, by considering it as a superposition of electrostatic force calculations.

Error control in computational uid dynamics (CFD) has been crucial for reliability and e ciency of numerical ow simulations. The roles of truncation and rounding errors in difference approximations are discussed. Truncation error control is reviewed for ODEs. For di erence approximations of PDEs, discretization error control by Richardson extrapolation is outlined. Applications to anisotropic g...

A new grid adaptation strategy, which minimizes the truncation error of a pth-order nite di erence approximation, is proposed. The main idea of the method is based on the observation that the global truncation error associated with discretization on nonuniform meshes can be minimized if the interior grid points are redistributed in an optimal sequence. The method does not explicitly require the...