Results 71 to 80 of about 6,536,345 (211)

Sharp function estimates and boundedness for Toeplitz-type operators associated with general fractional integral operators

open access: yesOpen Mathematics, 2021
In this paper, we establish some sharp maximal function estimates for certain Toeplitz-type operators associated with some fractional integral operators with general kernel.
Chen Dazhao, Huang Hui
doaj   +1 more source

Operator Lipschitz functions (English translation)

open access: yes, 2016
The purpose of this survey is a comprehensive study of operator Lip\-schitz functions. A continuous function $f$ on the real line ${\Bbb R}$ os called operator Lipschitz if $\|f(A)-f(B)\|\le\operatorname{const}\|A-B\|$ for arbitrary self-adjoint operators $A$ and $B$. We give sufficient conditions and necessary conditions for operator Lipschitzness. We
Aleksandrov, Alexei, Peller, Vladimir
openaire   +2 more sources

A Gauss–Newton Method for ODE Optimal Tracking Control

open access: yesOptimal Control Applications and Methods, EarlyView.
This paper presents a Gauss–Newton method for optimal tracking control of ordinary differential equations (ODEs). The approach formulates the problem as an infinite‐dimensional optimization problem, allowing both control functions and uncertain model parameters to be optimized.
Vicky Holfeld   +2 more
wiley   +1 more source

Algebraic reflexivity of isometry groups and automorphism groups of some operator structures [PDF]

open access: yes, 2013
We establish the algebraic re exivity of three isometry groups of operator structures: The group of all surjective isometries on the unitary group, the group of all surjective isometries on the set of all positive invertible operators equipped with ...
Botelho, Fernanda   +2 more
core  

Data‐driven emulation of flow‐dependent background‐error variance in variational data assimilation

open access: yesQuarterly Journal of the Royal Meteorological Society, EarlyView.
A machine‐learning approach is developed to emulate flow‐dependent background‐error variance within a variational data assimilation framework. The method reproduces uncertainty information that would normally require a 50‐member ensemble using only five members, while maintaining comparable observation fit and forecast performance.
Wei Pan   +3 more
wiley   +1 more source

Boundedness of Toeplitz type operators associated to Riesz potential operator with general kernel on Orlicz space

open access: yesOpen Mathematics, 2015
In this paper, the boundedness properties for some Toeplitz type operators associated to the Riesz potential and general integral operators from Lebesgue spaces to Orlicz spaces are proved.
Chen Dazhao
doaj   +1 more source

Integral representation of a solution to the Stokes-Darcy problem [PDF]

open access: yes, 2015
With methods of potential theory we develop a representation of a solution of the coupled Stokes-Darcy model in a Lipschitz domain for boundary data in H-1 ...
Medková, Dagmar   +6 more
core   +1 more source

Exact Robust Filtering and Differentiation Based on Sliding Modes and Homogeneity

open access: yesInternational Journal of Robust and Nonlinear Control, EarlyView.
ABSTRACT This article addresses the problem of online estimation of the derivatives of a signal corrupted by measurement noise. The measured signal is modeled as the sum of a smooth nominal component and a uniformly bounded noise term. A key objective is to attenuate the effect of high‐frequency noise.
Jaime A. Moreno, Arie Levant
wiley   +1 more source

The Lifshitz–Krein trace formula and operator Lipschitz functions

open access: yesProceedings of the American Mathematical Society, 2016
We solve a problem by M.G. Krein and describe the maximal class of functions f f on the real line, for which the Lifshitz ...
openaire   +3 more sources

Applications of Inverse Limits to Extensions of Operators and Approximation of Lipschitz Functions

open access: yesJournal of Approximation Theory, 2002
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Jacek Tabor, David T. Yost
openaire   +3 more sources

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