Results 1 to 10 of about 76,535 (61)

Refinements of numerical radius inequalities using the Kantorovich ratio

open access: yesConcrete Operators, 2022
In this paper, we improve some numerical radius inequalities for Hilbert space operators under suitable condition. We also compare our results with some known results. As application of our result, we obtain an operator inequality.
Nikzat Elham, Omidvar Mohsen Erfanian
doaj   +1 more source

On the Upper Bound of the Third Hankel Determinant for Certain Class of Analytic Functions Related with Exponential Function

open access: yesAnalele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2022
In the present paper we introduce a new class of analytic functions f in the open unit disk normalized by f(0) = f′(0)−1 = 0, associated with exponential functions.
Breaz Daniel   +2 more
doaj   +1 more source

Code generation approaches for parallel geometric multigrid solvers

open access: yesAnalele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2020
Software development for applications in computational science and engineering has become complex in recent years. This is mainly due to the increasing parallelism and heterogeneity in modern computer architectures and to the more realistic physical and ...
Köstler Harald   +5 more
doaj   +1 more source

On numerical solution of nonlinear parabolic multicomponent diffusion-reaction problems

open access: yesAnalele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2021
This work continues our previous analysis concerning the numerical solution of the multi-component mass transfer equations. The present test problems are two-dimensional, parabolic, non-linear, diffusion- reaction equations. An implicit finite difference
Juncu Gh., Popa C., Sarbu Gh.
doaj   +1 more source

A Benchmark Generalization of Fuzzy Soft Ideals in Ordered Semigroups

open access: yesAnalele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2021
In real life, variability and inaccuracy are always presentand must be calculated by either possibilistic, probabilistic, polymorphic or other uncertainty approach. This benchmark study is about to construct new types of fuzzy soft ideals i.e., (∈, ∈ ∨qk)
Khan Faiz Muhammad   +3 more
doaj   +1 more source

Unitarily invariant norm inequalities for operators

open access: yesJournal of the Egyptian Mathematical Society, 2012
We present several norm inequalities for Hilbert space operators. In particular, we prove that if A1,A2,…,An∈B(H), then |||A1A2∗+A2A3∗+⋯+AnA1∗|||⩽∑i=1nAiAi∗for all unitarily invariant norms. We also show that if A1,A2,A3,A4 are projections in B(H), then ∑
M. Erfanian Omidvar   +2 more
doaj   +1 more source

On approximation properties of some non-positive Bernstein-Durrmeyer type operators

open access: yesAnalele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2023
In this paper we shall introduce a new type of Bernstein Durrmeyer operators which are not positive on the entire interval [0, 1]. For these operators we will study the uniform convergence on all continuous functions on [0, 1] as well as a result given ...
Vasian Bianca Ioana
doaj   +1 more source

New aspects in polygroup theory

open access: yesAnalele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2020
The aim of this paper is to compute the commutativity degree in polygroup’s theory, more exactly for the polygroup PG and for extension of polygroups by polygroups, obtaining boundaries for them.
Sonea Andromeda Cristina
doaj   +1 more source

Joint numerical ranges: recent advances and applications minicourse by V. Müller and Yu. Tomilov

open access: yesConcrete Operators, 2020
We present a survey of some recent results concerning joint numerical ranges of n-tuples of Hilbert space operators, accompanied with several new observations and remarks.
Müller V., Tomilov Yu.
doaj   +1 more source

Existence and uniqueness of solutions for certain functional equations and system of functional equations arising in dynamic programming

open access: yesAnalele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2016
This paper deals with the existence, uniqueness and iterative approximations of solutions for the functional equations and system of functional equations arising in dynamic programming of multistage decision making processes in Banach spaces and complete
Deepmala, Agarwal Ravi P.
doaj   +1 more source

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