Results 21 to 30 of about 10,406 (269)
Efficient approximation of random fields for numerical applications [PDF]
, 2014 This article is dedicated to the rapid computation of separable expansions for the approximation of random fields. We consider approaches based on techniques from the approximation of non-local operators on the one hand and based on the pivoted Cholesky ...
Michael Peters +5 more
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ON LOCAL APPROXIMATION OF POSITIVE OPERATORS
Demonstratio Mathematica, 2002 The main purpose of the paper is to extend some up-down theorems obtained by \textit{G. J. H. M. Buskes, P. G. Dodds, B. de Patger} and \textit{A. R. Schep} [Indag. Math. 48, 1--9 (1986; Zbl 0597.46009)] who proved that if \(E\) is a Banach lattice with quasi-interior points, \(F\) is a Dedekind complete Riesz space and \(\tilde F_n\) separates the ...
Alpay, Şafak, UYAR, AYŞE
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On approximation of functions by certain operators preserving $x^2$ [PDF]
, 2008 summary:In this paper we extend the Duman-King idea of approximation of functions by positive linear operators preserving $e_k (x)=x^k$, $k=0,2$. Using a modification of certain operators $L_n$ preserving $e_0$ and $e_1$, we introduce operators $L_n ...
Lucyna Rempulska +5 more
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Estimates of the Approximation Error Using Rademacher Complexity: Learning Vector-Valued Functions [PDF]
, 2008 For certain families of multivariable vector-valued functions to be approximated, the accuracy of approximation schemes made up of linear combinations of computational units containing adjustable parameters is investigated.
Gnecco Giorgio +7 more
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Probabilistic methods in the approximation by linear positive operators [PDF]
, 1980 By the theorem of Daniell-Stone a probabilistic interpretation of sequences of linear positive operators in approximation theory is given which yields a generalization of Korovkin's theorem in the context of uniform integrability.
Walk, Harro
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Indefinite Hamiltonian systems whose Titchmarsh–Weyl coefficients have no finite generalized poles of non-positive type [PDF]
, 2013 The two-dimensional Hamiltonian system (*) y'(x)=zJH(x)y(x), x∈(a,b), where the Hamiltonian H takes non-negative 2x2-matrices as values, and $J:= \begin{pmatrix} 0 & -1 \\ 1 & 0 \end{pmatrix}$, has attracted a lot of interest over the past decades ...
Harald Woracek +3 more
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Unitary approximation of positive operators
Illinois Journal of Mathematics, 1980 Of concern are some operators inequalities arising in quantum chemistry. Let $A$ be a positive operator on a Hilbert space $\mathcal{H}$. We consider the minimization of $||U-A||_{p}$ as $U$ ranges over the unitary operators in $\mathcal{H}$ and prove that in most cases the minimum is attained when $U$ is the identity operator. The norms considered are
Aiken, John G. +2 more
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Approximation by generalized positive linear Kantorovich operators [PDF]
, 2017 In the present article, we introduce generalized positive linear-Kantorovich operators depending on P?lya-Eggenberger distribution (PED) as well as inverse P?lya-Eggenberger distribution (IPED) and for these operators, we study some ...
Naokant Deo, Minakshi Dhamija
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Caputo Fractional Approximation Using Positive Sublinear Operators [PDF]
, 2018 Here we consider the approximation of functions by sublinear positive operators with applications to a big variety of Max-Product operators under Caputo fractional differentiability.
Anastassiou, George A. +1 more
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On Ritz approximations for positive definite operators I (theory) [PDF]
Linear Algebra and its Applications, 2006 We give new lower bounds on the Rayleigh--Ritz approximations of a part of the spectrum of an elliptic operator. Furthermore, we present bounds for the accompanying Ritz vectors. The bounds include a form of a relative gap between the Ritz values and the rest of the spectrum of the operator.
Grubišić, Luka, Veselić, Krešimir
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