Results 51 to 60 of about 3,554 (232)

Image space formalism of convolutional neural networks for k‐space interpolation

Magnetic Resonance in Medicine, Volume 94, Issue 6, Page 2680-2701, December 2025.
Abstract Purpose Noise resilience in image reconstructions by scan‐specific robust artificial neural networks for k‐space interpolation (RAKI) is linked to nonlinear activations in k‐space. To gain a deeper understanding of this relationship, an image space formalism of RAKI is introduced for analyzing noise propagation analytically, identifying and ...
P. Dawood, F. Breuer, M. Gram, I. Homolya, P. M. Jakob, M. Zaiss, M. Blaimer   +6 more
wiley   +1 more source

On Boundedness of Calderón–Toeplitz Operators [PDF]

Integral Equations and Operator Theory, 2011
We study the boundedness of Toeplitz-type operators defined in the context of the Calder n reproducing formula considering the specific wavelets whose Fourier transforms are related to Laguerre polynomials. Some sufficient conditions for simultaneous boundedness of these Calder n-Toeplitz operators on each wavelet subspace for unbounded symbols are ...
openaire   +2 more sources

Dynamic contrast enhanced‐magnetic resonance fingerprinting (DCE‐MRF): A new quantitative MRI method to reliably assess tumor vascular perfusion

Magnetic Resonance in Medicine, Volume 94, Issue 6, Page 2578-2592, December 2025.
Abstract Purpose The clinical utility of conventional DCE‐MRI methods is limited by the use of conventional qualitative dynamic T1‐weighted images, resulting in poor reproducibility. This study presents the initial implementation of a new DCE‐magnetic resonance fingerprinting (DCE‐MRF) methodology to provide reproducible, quantitative assessments of ...
Christina J. MacAskill, Yuran Zhu, Guanhua Wang, Bernadette O. Erokwu, Chetan B. Dhakan, Andrew Dupuis, Barbara J. Schiemann, Michael Kavran, Chunying Wu, William P. Schiemann, Mark A. Griswold, Xin Yu, Mark D. Pagel, Chris A. Flask   +13 more
wiley   +1 more source

An Optimal Preconditioned MINRES Method for Symmetrized Multilevel Block Toeplitz Systems With Applications

Numerical Linear Algebra with Applications, Volume 32, Issue 6, December 2025.
ABSTRACT In this work, we propose a novel preconditioned minimal residual method for a class of real, nonsymmetric multilevel block Toeplitz systems, which generalizes an ideal preconditioner established in [J. Pestana. Preconditioners for symmetrized Toeplitz and multilevel Toeplitz matrices. SIAM Journal on Matrix Analysis and Applications, 40(3):870–
Grigorios Tachyridis, Sean Y. Hon
wiley   +1 more source

On Calder�n-Toeplitz operators

Monatshefte f�r Mathematik, 1993
Let \(\psi\in L^ 2(\mathbb{R}^ d)\) be an admissible wavelet, \(\psi_ \xi(x)= t^{-d/2} \psi\Bigl({x-v\over t}\Bigr)\), \(\xi= (v,t)\), \(G\) the ``\(ax+ b\)''-group, i.e. \(G=\{\xi= (v,t): v\in \mathbb{R}^ d, t>0\}\), \(d\xi= t^{d-1}dv dt\) the left invariant measure on \(G\).
openaire   +1 more source

Low‐Rank Geostatistical Inversion for Spatiotemporal Heterogeneity of Aquitard Hydraulic Parameters

Water Resources Research, Volume 61, Issue 12, December 2025.
Abstract Many hydrogeological processes are intricately linked to both the spatial heterogeneity and temporal dynamics of the involved parameters. The variability in hydrogeological parameters across both space and time domains is defined as the spatiotemporal heterogeneity.
Chao Zhuang, Zhongxu Li, Ubaid Ullah, Long Yan, Rui Hu, Zhi Dou, Zhifang Zhou, Jinguo Wang, Walter A. Illman   +8 more
wiley   +1 more source

Hyponormality of Toeplitz operators with non-harmonic symbols on the Bergman spaces

Journal of Inequalities and Applications, 2021
In this paper, we present some necessary and sufficient conditions for the hyponormality of Toeplitz operator T φ $T_{\varphi }$ on the Bergman space A 2 ( D ) $A^{2}(\mathbb{D})$ with non-harmonic symbols under certain assumptions.
Sumin Kim, Jongrak Lee
doaj   +1 more source

On Bergman–Toeplitz operators in periodic planar domains

Transactions of the London Mathematical Society, Volume 12, Issue 1, December 2025.
Abstract We study spectra of Toeplitz operators Ta$T_a$ with periodic symbols in Bergman spaces A2(Π)$A^2(\Pi)$ on unbounded singly periodic planar domains Π$\Pi$, which are defined as the union of infinitely many copies of the translated, bounded periodic cell ϖ$\varpi$.
Jari Taskinen
wiley   +1 more source

Shifted model spaces and their orthogonal decompositions [PDF]

Opuscula Mathematica
We generalize certain well known orthogonal decompositions of model spaces and obtain similar decompositions for the wider class of shifted model spaces, allowing us to establish conditions for near invariance of the latter with respect to certain ...
M. Cristina Câmara, Kamila Kliś-Garlicka, Marek Ptak   +2 more
doaj   +1 more source

Commutative Banach Algebras Generated by Toeplitz Operators on the Bergman Space [PDF]

, 2022
Miguel Ángel Rodríguez Rodríguez
openalex   +1 more source