Hostname: page-component-76fb5796d-9pm4c Total loading time: 0 Render date: 2024-04-29T00:50:52.405Z Has data issue: false hasContentIssue false

Sigmoidal cosine series on the interval

Published online by Cambridge University Press:  17 February 2009

Beong In Yun
Affiliation:
Faculty of Mathematics, Informatics and Statistics, Kunsan National University, 573–701, Korea; e-mail: biyun@kunsan.ac.kr or paulll@maths.uq.edu.au.
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

We construct a set of functions, say, composed of a cosine function and a sigmoidal transformation γr of order r > 0. The present functions are orthonormal with respect to a proper weight function on the interval [−1, 1]. It is proven that if a function f is continuous and piecewise smooth on [−1, 1] then its series expansion based on converges uniformly to f so long as the order of the sigmoidal transformation employed is 0 < r ≤ 1. Owing to the variational feature of according to the value of r, one can expect improvement of the traditional Fourier series approximation for a function on a finite interval. Several numerical examples show the efficiency of the present series expansion in comparison with the Fourier series expansion.

Type
Research Article
Copyright
Copyright © Australian Mathematical Society 2006

References

[1]Choi, U. J., Kim, S. W. and Yun, B. I., “Improvement of the asymptotic behavior of the EulerMaclaurin formula for Cauchy principal value and Hadamard finite-part integrals”, Int. J. Numer Meth. Engng. 61 (2004) 496513.CrossRefGoogle Scholar
[2]Elliott, D., “The Euler-Maclaurin formula revisited”, J. Austral. Math. Soc. Ser. B 40(E) (1998) E27–E76.Google Scholar
[3]Elliott, D., “Sigmoidal transformations and the trapezoidal rule”, J. Austral. Math. Soc. Ser. B 40(E) (1998) E77–E137.Google Scholar
[4]Elliott, D. and Venturino, E., “Sigmoidal transformations and the Euler-Maclaurin expansion for evaluating certain Hadamard finite-part integrals”, Numer Math. 77 (1997) 453465.CrossRefGoogle Scholar
[5]Folland, G. B., Fourier Analysis and Its Applications(Wadsworth & Brooks/Cole, 1992).Google Scholar
[6]Gradshteyn, I. S. and Ryzhik, I. M., Table of Integrals, Series, and Products, 6th ed. (Academic Press, San Diego, CA, 2000).Google Scholar
[7]Jerri, A. J., The Gibbs Phenomenon in Fourier Analysis, Splines and Wavelet Approximations (Kluwer Academic Publisher, Dordrecht, 1998).CrossRefGoogle Scholar
[8]Johnston, P. R., “Application of sigmoidal transformations to weakly singular and near singular boundary element integrals”, Int. J. Numer. Meth. Engng. 45 (1999) 13331348.3.0.CO;2-Q>CrossRefGoogle Scholar
[9]Pinkus, A. and Zafrany, S., Fourier Analysis and Integral Transforms (Cambridge University Press, Cambridge, 1997).Google Scholar
[10]Prössdorf, S. and Rathsfeld, A., “On an integral equation of the first kind arising from a cruciform crack problem”, in Integral Equations and Inverse Problems (eds. Petkov, V. and Lazarov, R.), (Longman, Harlow, 1991) 210219.Google Scholar
[11]Sidi, A., “A new variable transformation for numerical integration”, in Numerical Integration IV ISNM Vol. 112 (eds. Brass, H. and Hämmerlin, G.), (Birkhaüser, Basel, 1993) 359373.Google Scholar
[12]Yun, B. I., “An extended sigmoidal transformation technique for evaluating weakly singular integrals without splitting the integration interval”, SIAM J. Sci. Comput. 25 (2003) 284301.CrossRefGoogle Scholar
[13]Yun, B. I., “A generalized non-linear transformation for evaluating singular integrals”, Int. J. Numer. Meth. Engng. 65 (2006) 19471969.CrossRefGoogle Scholar
[14]Yun, B. I. and Kim, P., “A new sigmoidal transformation for weakly singular integrals in the boundary element method”, SIAM J. Sci. Comput. 24 (2003) 12031217.CrossRefGoogle Scholar