Results 21 to 30 of about 264 (60)
Almost periodic functions on time scales and their properties
Open MathematicsIn this article, we first propose a concept of almost periodic functions on arbitrary time scales, which is defined by trigonometric polynomial approximations with respect to supremum norm, and study some basic properties of these kinds of functions ...
Li Yongkun, Huang Xiaoli
doaj +1 more source
A Levinson-Galerkin algorithm for regularized trigonometric approximation
, 1999 Trigonometric polynomials are widely used for the approximation of a smooth function $f$ from a set of nonuniformly spaced samples $\{f(x_j)\}_{j=0}^{N-1}$.
Strohmer, Thomas
core +3 more sources
Weyl almost periodic functions on time scales and their Fourier series
Demonstratio MathematicaIn this paper, firstly, we propose a concept of Weyl almost periodic functions on time scales by trigonometric polynomial approximation, and study some basic properties of Weyl almost periodic functions on time scales.
Li Yongkun, Huang Xiaoli
doaj +1 more source
, 2005 We analyze a sublinear RAlSFA (Randomized Algorithm for Sparse Fourier Analysis) that finds a near-optimal B-term Sparse Representation R for a given discrete signal S of length N, in time and space poly(B,log(N)), following the approach given in \cite ...
Daubechies, Ingrid +3 more
core +4 more sources
Some extremal functions in Fourier analysis, III
, 2008 We obtain the best approximation in $L^1(\R)$, by entire functions of exponential type, for a class of even functions that includes $e^{-\lambda|x|}$, where $\lambda >0$, $\log |x|$ and $|x|^{\alpha}$, where $-1 < \alpha < 1$.
A. Selberg +17 more
core +2 more sources
Universal matrix transforms of holomorphic functions [PDF]
, 2006 The phenomenon of overconvergence is related with the convergence of subsequences of the sequence of partial sums of Taylor series at points outside their disk of convergence.
Bernal González, Luis +2 more
core
Equivalence Between K-functionals Based on Continuous Linear Transforms [PDF]
, 2007 2000 Mathematics Subject Classification: 46B70, 41A10, 41A25, 41A27, 41A35, 41A36, 42A10.The paper presents a method of relating two K-functionals by means of a continuous linear transform of the function.
Draganov, Borislav, Ivanov, Kamen
core
Embracing off-the-grid samples. [PDF]
Sampl Theory Signal Process Data Anal, 2023 López O, Yılmaz Ö.
europepmc +1 more source
Fast multi-dimensional scattered data approximation with Neumann boundary conditions
, 2003 An important problem in applications is the approximation of a function $f$ from a finite set of randomly scattered data $f(x_j)$. A common and powerful approach is to construct a trigonometric least squares approximation based on the set of exponentials
Grishin, Denis, Strohmer, Thomas
core
Accelerating the convergence of trigonometric series
Open Mathematics, 2006 Nersessian Anry, Poghosyan Arnak
doaj +1 more source