We obtain a property which characterizes the Chebyshev orthogonal polynomials of first, second, third, and fourth kind. Indeed, we prove that the four Chebyshev sequences are the unique classical orthogonal polynomial families such that their linear combinations, with fixed length and constant coefficients, can be orthogonal polynomial sequences. 1. Introduction The classical orthogonal polynom...

A difficulty that arises in the context of infinite d−periodic rough-surface scattering relates to the effective numerical evaluation of the corresponding “quasi-periodic Green function” Gqp. Due to its relevance in a variety of applications, this problem has generated significant interest over the last 40 years, and a variety of numerical methods have been devised for this purpose. None of the...

In the Laurent expansion ζ(s, a) = 1 s− 1 + ∞ ∑ k=0 (−1)γk(a) k! (s− 1) , 0 < a ≤ 1, of the Riemann-Hurwitz zeta function, the coefficients γk(a) are known as Stieltjes, or generalized Euler, constants. [When a = 1, ζ(s, 1) = ζ(s) (the Riemann zeta function), and γk(1) = γk.] We present a new approach to high-precision approximation of γk(a). Plots of our results reveal much structure in the gr...

The aim of the present paper is to find efficient method computation wave-making resistance a ship using mitchell’s integral. computational schemes described in publications suggest use simple quadratures (trapezoidal and Simpson’s rule) with fixed number integration’s intervals. This approach assumes manual setup algorithm for calculating each new makes it difficult estimate error obtained res...

The purpose of this paper is to reduce the complexity computing components integral Fm-transform, m≥0, whose analytic expressions include definite integrals. We propose use nontrivial quadrature rules with nonuniformly distributed integration points instead widely used Newton–Cotes formulas. As weight function that determines orthogonality, we choose generating fuzzy partition associated Fm-tra...

This thesis discusses strategies for numerically solving a two dimensional integral. The difficulties here are due to numerous integrands and regions in R2. The transformation to units as the 2-simplex and the cube can simplify many integrands. An approach to arbitrary regions is to decompose them into easy ones as triangles and rectangles. For these regions formulas that approximate the two di...

We study the kernels of the remainder term Rn,s(f) of GaussTurán quadrature formulas ∫ 1 −1 f(t)w(t) dt = n ∑

We show that, for a finite set A of real numbers, the size of the set A + A A + A = { a + b c + d : a, b, c, d ∈ A, c + d 6= 0 } is bounded from below by ∣∣∣∣A + A A + A ∣∣∣∣ |A|2+1/4 |A/A|1/8 log |A| . This improves a result of Roche-Newton (2016).