-widths for singularly perturbed problems
-widths for singularly perturbed problems
Kolmogorov -widths are an approximation theory concept that, for a given problem, yields information about the optimal rate of convergence attainable by any numerical method applied to that problem. We survey sharp bounds recently obtained for the -widths of certain singularly perturbed convection-diffusion and reaction-diffusion boundary value problems.
Nachtrag zu G. Leha: Relative Korovkin-Sätze und Ränder.
Natural and smoothing quadratic spline. (An elementary approach)
For quadratic spine interpolating local integrals (mean-values) on a given mesh the conditions of existence and uniqueness, construction under various boundary conditions and other properties are studied. The extremal property of such's spline allows us to present an elementary construction and an algorithm for computing needed parameters of such quadratic spline smoothing given mean-values. Examples are given illustrating the results.
Natural Spline Functions, Their Associated Eigenvalue Problem.
Nearby linear Chebyshev approximation.
Nearby linear Chebyshev approximation. (Short Communication).
Nearly Coconvex Approximation
* Part of this work was done while the second author was on a visit at Tel Aviv University in March 2001Let f ∈ C[−1, 1] change its convexity finitely many times, in the interval. We are interested in estimating the degree of approximation of f by polynomials, and by piecewise polynomials, which are nearly coconvex with it, namely, polynomials and piecewise polynomials that preserve the convexity of f except perhaps in some small neighborhoods of the points where f changes its convexity. We obtain...
Nearly farthest points in normed linear spaces
Necessary and sufficient conditions for almost regularity of uniform Birkfoff interpolation schemes.
Nekotorye ponyatiya i sootnosheniya kinematiche skoi geometrii
Nested derivatives: a simple method for computing series expansions of inverse functions.
New characterization for nonlinear weighted best simultaneous approximation.
New error inequalities for the Lagrange interpolating polynomial.
New inequalities obtained by means of quadrature formulae.
New limit formulas for the convolution of a function with a measure and their applications.
New Minimality Properties of Gaussian Quadratures.
New norm type inequalities for linear mappings.
Newton interpolating series at distinct points with coefficients in a real Banach algebra.
Nonlinear Approximation by Trigonometric Sums.