Approximation of almost periodic functions by convolution type operators.
Approximation of almost periodic functions by periodic ones
It is not the purpose of this paper to construct approximations but to establish a class of almost periodic functions which can be approximated, with an arbitrarily prescribed accuracy, by continuous periodic functions uniformly on .
Approximation of functions from by general linear operators of their Fourier series
We show the general and precise conditions on the functions and modulus of continuity as well as on the entries of matrices generating the summability means and give the rates of approximation of functions from the generalized integral Lipschitz classes by double matrix means of their Fourier series. Consequently, we give some results on norm approximation. Thus we essentially extend and improve our earlier results [Acta Comment. Univ. Tartu. Math. 13 (2009), 11-24] and the result of S. Lal [Appl....
Approximation of functions from by linear operators of conjugate Fourier series
We show the results corresponding to some theorems of S. Lal and H. K. Nigam [Int. J. Math. Math. Sci. 27 (2001), 555-563] on the norm and pointwise approximation of conjugate functions and to the results of the authors [Acta Comment. Univ. Tartu. Math. 13 (2009), 11-24] also on such approximations.
Approximation of functions possessing derivatives of positive orders
Approximation of periodic solutions of a system of periodic linear nonhomogeneous differential equations
The present paper does not introduce a new approximation but it modifies a certain known method. This method for obtaining a periodic approximation of a periodic solution of a linear nonhomogeneous differential equation with periodic coefficients and periodic right-hand side is used in technical practice. However, the conditions ensuring the existence of a periodic solution may be violated and therefore the purpose of this paper is to modify the method in order that these conditions remain valid....
Approximation of signals (functions) belonging to the weighted -class by linear operators.
Approximation of translation invariant operators
Approximation on the sphere by weighted Fourier expansions.
Approximation properties of partial sums of Fourier series.
Approximation properties of periodic interpolation by translates of one function
Approximation properties of the partial sums of Fourier series of some almost periodic functions
Approximation to continuous functions in the Hölder metric
Approximations- und Eindeutigkeitssatz für Exponentialsysteme mit komplexen Exponenten.
Approximationsgüte der Ableitungen bei trigonometrischer Interpolation.
Arithmetical functions with periodic zeros
Asymptotic behavior of moment sequences.
Asymptotic Fourier and Laplace transformations for hyperfunctions
We develop an elementary theory of Fourier and Laplace transformations for exponentially decreasing hyperfunctions. Since any hyperfunction can be extended to an exponentially decreasing hyperfunction, this provides simple notions of asymptotic Fourier and Laplace transformations for hyperfunctions, improving the existing models. This is used to prove criteria for the uniqueness and solvability of the abstract Cauchy problem in Fréchet spaces.
Asyptotic Behaviour of Multiperiodic Functions G(x) = ... g (x/2...).
Attenuation Factors in Multivariate Fourier Analysis.