Results 21 to 30 of about 151 (41)

A DEIM Induced CUR Factorization [PDF]

, 2016
We derive a CUR approximate matrix factorization based on the discrete empirical interpolation method (DEIM). For a given matrix ${\bf A}$, such a factorization provides a low-rank approximate decomposition of the form ${\bf A} \approx \bf C \bf U \bf R$,
Embree, Mark, Sorensen, D.C.
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Note on the shape-preservation of a new class of Kantorovich-type operators via divided differences

Demonstratio Mathematica
Shape-preserving approximation is a significant approximation method that has many application areas, such as computer-based geometric design, image processing, geodesy, chemistry, and robotics.
Turhan Nezihe
doaj   +1 more source

Minimal hermitian matrices with fixed entries outside the diagonal [PDF]

, 2008
We survey some results concerning the problem of finding the complex hermitian matrix or matrices of least supremum norm with variable diagonal. Some qualitative general results are given and more specific descriptions are shown for the 3 x 3 case.
Andruchow, Esteban, Mata Lorenzo, Luis E., Mendoza, Alberto., Recht, Lázaro, Varela, Alejandro   +4 more
core  

A uniform estimate of the relative projection constant

, 2017
The main goal of the paper is to provide a quantitative lower bound greater than $1$ for the relative projection constant $\lambda(Y, X)$, where $X$ is a subspace of $\ell_{2p}^m$ space and $Y \subset X$ is an arbitrary hyperplane.
Kobos, Tomasz
core   +1 more source

Estimates for Durrmeyer-type exponential sampling series in Mellin-Orlicz spaces

Demonstratio Mathematica
This study examines Durrmeyer-type exponential sampling series to obtain a quantitative estimate by using the concept of the logarithmic modulus of smoothness defined with the help of a suitable modular functional on Mellin-Orlicz spaces.
Kangal Esma, Kantar Ülkü Dinlemez
doaj   +1 more source

Multipliers for p-Bessel sequences in Banach spaces

, 2010
Multipliers have been recently introduced as operators for Bessel sequences and frames in Hilbert spaces. These operators are defined by a fixed multiplication pattern (the symbol) which is inserted between the analysis and synthesis operators.
A. Aldroubi, A. Aldroubi, A. Pietsch, A.F. Ruston, Asghar Rahimi, D. Wang, G. Matz, G. Matz, H. Rauhut, K. Gröchenig, M. Dörfler, M. Fornasier, M. Kowalski, M.R. Abodllahpour, O. Christensen, P. Balazs, P. Balazs, P. Balazs, P. Balazs, P. Balazs, P.G. Casazza, Peter Balazs, R. Schatten, R.M. Young   +23 more
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Multipliers for Continuous Frames in Hilbert Spaces

, 2012
In this paper we examine the general theory of continuous frame multipliers in Hilbert space. These operators are a generalization of the widely used notion of (discrete) frame multipliers.
Balazs, Peter, Bayer, Dominik, Rahimi, Asghar   +2 more
core   +1 more source

A coordinate free characterization of certain quasidiagonal operators [PDF]

, 2014
We obtain (i) a new, coordinate free, characterization of quasidiagonal operators with essential spectra contained in the unit circle by adapting the proof of a classical result in the theory of Banach spaces, (ii) an affirmative answer to some questions
Boedihardjo, March T.
core  

Redundancy of Fusion frames in Hilbert Spaces

, 2015
Upon improving and extending the concept of redundancy of frames, we introduce the notion of redundancy of fusion frames, which is concerned with the properties of lower and upper redundancies. These properties are achieved by considering the minimum and
Daraby, Bayaz, Rahimi, Asghar, Zandi, Golaleh   +2 more
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Lower bounds for the approximation with variation-diminishing splines [PDF]

We prove lower bounds for the approximation error of the variation-diminishing Schoenberg operator on the interval [0, 1] in terms of classical moduli of smoothness depending on the degree of the spline basis.
B. Forster, Badea, Beutel, Curry, de Boor, de Boor, de Boor, Gantmacher, Gavrea, Gershgorin, J. Nagler, Lyche, Marsden, Nürnberger, P. Cerejeiras, Pinkus, Rudin, Scherer, Schoenberg, Schoenberg, Schumaker, Timan, Zygmund   +22 more
core   +1 more source