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1,935 Results Found

  • Article
  • Open Access
5 Citations
2,703 Views
11 Pages

8 October 2022

The fractional Hilbert transform, a generalization of the Hilbert transform, has been extensively studied in the literature because of its widespread application in optics, engineering, and signal processing. In the present work, we expand the fracti...

(This article belongs to the Special Issue Applied Mathematics and Fractional Calculus II)
  • Article
  • Open Access
5 Citations
5,985 Views
24 Pages

An investigation of the concept of “surveyability” as traced through the thought of Hilbert, Wittgenstein, and Turing. The communicability and reproducibility of proof, with certainty, are seen as earmarked by the “surveyability&rdq...

(This article belongs to the Special Issue Turing the Philosopher: Established Debates and New Developments)
  • Article
  • Open Access
1,138 Views
14 Pages

17 January 2025

This paper studies the properties of the Fourier transform of the fuzzy function, and extends the classical Poisson integral formula on the half plane to the fuzzy case, obtaining the composition of the fuzzy set generated by a point in the complex f...

(This article belongs to the Section D2: Operations Research and Fuzzy Decision Making)
  • Article
  • Open Access
2 Citations
3,386 Views
20 Pages

Frame-Related Sequences in Chains and Scales of Hilbert Spaces

  • Peter Balazs,
  • Giorgia Bellomonte and
  • Hessam Hosseinnezhad

16 April 2022

Frames for Hilbert spaces are interesting for mathematicians but also important for applications in, e.g., signal analysis and physics. In both mathematics and physics, it is natural to consider a full scale of spaces, and not only a single one. In t...

(This article belongs to the Special Issue Time-Frequency Analysis, Distributions, and Operators)
  • Article
  • Open Access
5 Citations
2,599 Views
15 Pages

Soft Frames in Soft Hilbert Spaces

  • Osmin Ferrer,
  • Arley Sierra and
  • José Sanabria

14 September 2021

In this paper, we use soft linear operators to introduce the notion of discrete frames on soft Hilbert spaces, which extends the classical notion of frames on Hilbert spaces to the context of algebraic structures on soft sets. Among other results, we...

  • Article
  • Open Access
4 Citations
2,333 Views
13 Pages

30 January 2024

This manuscript aims to provide a new characterization of Sheffer stroke Hilbert algebras due to their ideals and proposes stabilizers. In the setup of the main results, we construct particular subsets of Sheffer stroke Hilbert algebras and we propos...

(This article belongs to the Special Issue Computational Algebra, Coding Theory and Cryptography: Theory and Applications)
  • Article
  • Open Access
5 Citations
2,864 Views
11 Pages

2 February 2019

In this paper, we present several new inequalities for weaving frames in Hilbert spaces from the point of view of operator theory, which are related to a linear bounded operator induced by three Bessel sequences and a scalar in the set of real number...

(This article belongs to the Special Issue Inequalities)
  • Article
  • Open Access
4 Citations
3,002 Views
23 Pages

3 April 2024

We consider some basic problems associated with quantum mechanics of systems having a time-dependent Hilbert space. We provide a consistent treatment of these systems and address the possibility of describing them in terms of a time-independent Hilbe...

(This article belongs to the Special Issue Quantum Dynamics with Non-hermitian Hamiltonians II)
  • Review
  • Open Access
15 Citations
5,641 Views
40 Pages

Groups, Special Functions and Rigged Hilbert Spaces

  • Enrico Celeghini,
  • Manuel Gadella and
  • Mariano A. del Olmo

27 July 2019

We show that Lie groups and their respective algebras, special functions and rigged Hilbert spaces are complementary concepts that coexist together in a common framework and that they are aspects of the same mathematical reality. Special functions se...

(This article belongs to the Special Issue Harmonic Analysis and Applications)
  • Article
  • Open Access
2 Citations
2,716 Views
9 Pages

29 December 2022

Quaternionic Hilbert spaces play an important role in applied physical sciences especially in quantum physics. In this paper, the operator valued frames on quaternionic Hilbert spaces are introduced and studied. In terms of a class of partial isometr...

  • Article
  • Open Access
2 Citations
4,529 Views
11 Pages

Reproducing Kernel Hilbert Space vs. Frame Estimates

  • Palle E. T. Jorgensen and
  • Myung-Sin Song

8 July 2015

We consider conditions on a given system F of vectors in Hilbert space H, forming a frame, which turn H into a reproducing kernel Hilbert space. It is assumed that the vectors in F are functions on some set Ω . We then identify conditions on these fu...

  • Article
  • Open Access
6 Citations
4,558 Views
15 Pages

Quadratic-Phase Hilbert Transform and the Associated Bedrosian Theorem

  • Hari M. Srivastava,
  • Firdous A. Shah,
  • Huzaifa L. Qadri,
  • Waseem Z. Lone and
  • Musadiq S. Gojree

19 February 2023

The Hilbert transform is a commonly used linear operator that separates the real and imaginary parts of an analytic signal and is employed in various fields, such as filter design, signal processing, and communication theory. However, it falls short...

(This article belongs to the Special Issue Mathematical Analysis and Applications, 4th Edition)
  • Article
  • Open Access
1 Citations
1,130 Views
16 Pages

7 March 2025

In this paper, we give the generalized Cauchy–Schwarz inequality and an extension of Buzano inequality on quasi-Hilbert C*-modules. Additionally, the upper bounds of the numerical radius of bounded adjointable operators on Hilbert C*-modules ar...

  • Article
  • Open Access
20 Citations
3,000 Views
23 Pages

Some Dynamic Hilbert-Type Inequalities on Time Scales

  • Ghada AlNemer,
  • Mohammed Zakarya,
  • Hoda A. Abd El-Hamid,
  • Praveen Agarwal and
  • Haytham M. Rezk

25 August 2020

Throughout this article, we will demonstrate some new generalizations of dynamic Hilbert type inequalities, which are used in various problems involving symmetry. We develop a number of those symmetric inequalities to a general time scale. From these...

(This article belongs to the Special Issue Advanced Calculus in Problems with Symmetry)
  • Article
  • Open Access
1 Citations
2,818 Views
10 Pages

Hilbert-Coding Metasurface for Diverse Electromagnetic Controls

  • Jianjiao Hao,
  • Fuju Ye,
  • Ying Ruan,
  • Lei Chen and
  • Haoyang Cui

26 August 2022

Metamaterials, or metasurfaces, allow the flexible and efficient manipulation of electromagnetic (EM) wave. Although the passive coding metasurfaces have achieved a great deal of functionality, they also need a complex design process. In this paper,...

(This article belongs to the Special Issue Metamaterials and Metasurfaces: Fundamentals and Applications)
  • Article
  • Open Access
1,100 Views
10 Pages

A Note on Injective g-Frames in Quaternionic Hilbert Spaces

  • Jianxia Zhang,
  • Fugen Gao and
  • Guoqing Hong

3 December 2024

Motivated by recent advancements in the quantum detection problem employing both discrete and continuous frames, this paper delves into a quantum detection problem utilizing g-frames within the context of quaternionic Hilbert spaces. We offer several...

(This article belongs to the Section Geometry and Topology)
  • Article
  • Open Access
1 Citations
1,654 Views
12 Pages

Quantum Injectivity of Frames in Quaternionic Hilbert Spaces

  • Zhenheng Xu,
  • Guoqing Hong,
  • Zuhua Guo and
  • Jianxia Zhang

11 July 2024

A quantum injective frame is a frame capable of differentiating states based on their respective frame measurements, whereas the quantum-detection problem associated with frames endeavors to delineate all such frames. In the present paper, the concep...

(This article belongs to the Section A: Algebra and Logic)
  • Article
  • Open Access
16 Citations
4,700 Views
13 Pages

6 September 2021

Enhancer-promoter interactions (EPIs) play a significant role in the regulation of gene transcription. However, enhancers may not necessarily interact with the closest promoters, but with distant promoters via chromatin looping. Considering the spati...

(This article belongs to the Special Issue Selected Papers from the 10th International Conference on Bioinformatics and Biomedical Science (ICBBS2021))
  • Article
  • Open Access
3 Citations
1,997 Views
11 Pages

Hilbert-Optic Diagnostics of Hydrogen-Oxygen Inverse Diffusion Flame

  • Vitaly Arbuzov,
  • Eduard Arbuzov,
  • Yuriy Dubnishchev,
  • Olga Zolotukhina and ,
  • Vladimir Lukashov and
  • Andrey Tupikin
  • + 1 author+ 0 author

16 December 2022

The aim of this work is to adapt the methods of optical Hilbert diagnostics for the visualization and study of inverse diffusion H2/O2 flame. The diagnostic complex is implemented on the basis of the IAB-451 device with modified optical filtering. Vi...

(This article belongs to the Section I2: Energy and Combustion Science)
  • Article
  • Open Access
1 Citations
1,772 Views
16 Pages

On Some Important Dynamic Inequalities of Hardy–Hilbert-Type on Timescales

  • Ahmed A. El-Deeb,
  • Dumitru Baleanu,
  • Clemente Cesarano and
  • Ahmed Abdeldaim

11 July 2022

In this article, by using some algebraic inequalities, nabla Hölder inequalities, and nabla Jensen’s inequalities on timescales, we proved some new nabla Hilbert-type dynamic inequalities on timescales. These inequalities extend some known...

(This article belongs to the Special Issue Ordinary and Partial Differential Equations: Theory and Applications II)
  • Article
  • Open Access
1 Citations
7,856 Views
9 Pages

The Invariant Subspace Problem for Separable Hilbert Spaces

  • Roshdi Khalil,
  • Abdelrahman Yousef,
  • Waseem Ghazi Alshanti and
  • Ma’mon Abu Hammad

2 September 2024

In this paper, we prove that every bounded linear operator on a separable Hilbert space has a non-trivial invariant subspace. This answers the well-known invariant subspace problem.

(This article belongs to the Special Issue Numerical Methods and Approximation Theory)
  • Article
  • Open Access
2 Citations
1,933 Views
17 Pages

5 February 2024

We investigate L2-approximation problems in the worst case setting in the weighted Hilbert spaces H(KRd,α,γ) with weights Rd,α,γ under parameters 1≥γ1≥γ2≥⋯≥0 and 1<α1≤α2≤;...

(This article belongs to the Special Issue Advanced Approximation Techniques and Their Applications)
  • Article
  • Open Access
2 Citations
2,132 Views
17 Pages

Diamond Alpha Hilbert-Type Inequalities on Time Scales

  • Ahmed A. El-Deeb,
  • Dumitru Baleanu,
  • Sameh S. Askar,
  • Clemente Cesarano and
  • Ahmed Abdeldaim

In this article, we will prove some new diamond alpha Hilbert-type dynamic inequalities on time scales which are defined as a linear combination of the nabla and delta integrals. These inequalities extend some known dynamic inequalities on time scale...

(This article belongs to the Special Issue Discrete Fractional Calculus, Local Fractional Inequalities, and Applications)
  • Review
  • Open Access
1 Citations
3,905 Views
28 Pages

29 November 2024

This paper explores the application of Hilbert topological spaces and linear operator algebra in the modelling and analysis of OFDM signals and wireless channels, where the channel is considered as a linear time-invariant (LTI) system. The wireless c...

  • Article
  • Open Access
1 Citations
1,750 Views
15 Pages

Some Remarks on Smooth Mappings of Hilbert and Banach Spaces and Their Local Convexity Property

  • Yarema A. Prykarpatskyy,
  • Petro Ya. Pukach,
  • Myroslava I. Vovk and
  • Michal Greguš

29 March 2024

We analyze smooth nonlinear mappings for Hilbert and Banach spaces that carry small balls to convex sets, provided that the radii of the balls are small enough. We focus on the study of new and mildly sufficient conditions for the nonlinear mapping o...

(This article belongs to the Section Hilbert’s Sixth Problem)
  • Feature Paper
  • Article
  • Open Access
3,822 Views
5 Pages

The Hilbert metric is a widely used tool for analysing the convergence of Markov processes and the ergodic properties of deterministic dynamical systems. A useful representation formula for the Hilbert metric was given by Liverani. The goal of the pr...

(This article belongs to the Special Issue Chaos and Randomness of Discrete Dynamical Systems: Their Use in Applied Science)
  • Article
  • Open Access
3 Citations
2,202 Views
12 Pages

Fault Identification in Membrane Structures Using the Hilbert Transforms

  • Aleksandra Waszczuk-Młyńska,
  • Adam Gałęzia and
  • Radkowski Stanisław

19 August 2022

Fault diagnostics present a crucial technical issue in the areas of both the condition monitoring of machines and the monitoring of structural health. The identification of faults at an early stage in their development has an immense effect on the sa...

(This article belongs to the Special Issue Sensors and Signal Processing for Fault Diagnosis and Failure Prognosis of Means of Transport)
  • Article
  • Open Access
1,110 Views
18 Pages

21 February 2025

This paper is devoted to the uniqueness of solutions for a class of nonhomogeneous stationary partial differential equations related to Hamilton–Jacobi-type equations in infinite-dimensional Hilbert spaces. Specifically, the uniqueness of the v...

(This article belongs to the Section E4: Mathematical Physics)
  • Article
  • Open Access
6 Citations
1,455 Views
10 Pages

19 December 2024

Hilbert-type integral inequalities, which feature a symmetric structure, are a significant class of inequalities with broad applications in the study of operator theory. Hilbert-type integral inequalities involving variable upper limit integral funct...

(This article belongs to the Section B: Mathematics)
  • Article
  • Open Access
9 Citations
2,003 Views
24 Pages

Some New Generalizations of Reverse Hilbert-Type Inequalities on Time Scales

  • Haytham M. Rezk,
  • Ghada AlNemer,
  • Ahmed I. Saied,
  • Omar Bazighifan and
  • Mohammed Zakarya

6 April 2022

This manuscript develops the study of reverse Hilbert-type inequalities by applying reverse Hölder inequalities on T. We generalize the reverse inequality of Hilbert-type with power two by replacing the power with a new power β,β>1....

(This article belongs to the Special Issue Symmetry in Nonlinear Equations: Mathematical Models, Methods and Applications Ⅱ)
  • Article
  • Open Access
14 Citations
3,042 Views
12 Pages

28 February 2020

We establish a new inequality of Hilbert-type containing positive homogeneous kernel ( min { m , n } ) λ and derive its equivalent forms. Based on the obtained Hilbert-type inequality, we discuss its equivalent forms and give the o...

(This article belongs to the Special Issue Advance in Nonlinear Analysis and Optimization)
  • Article
  • Open Access
2,916 Views
10 Pages

27 December 2018

In this paper, we obtain new inequalities for g-frames in Hilbert C * -modules by using operator theory methods, which are related to a scalar λ ∈ R and an adjointable operator with respect to two g-Bessel sequences. It is...

(This article belongs to the Special Issue Inequalities)
  • Article
  • Open Access
3 Citations
856 Views
29 Pages

The graph Hilbert transform (GHT) is a key tool in constructing analytic signals and extracting envelope and phase information in graph signal processing. However, its utility is limited by confinement to the graph Fourier domain, a fixed phase shift...

(This article belongs to the Special Issue Recent Advances in Fractional Fourier Transforms and Applications, 3rd Edition)
  • Article
  • Open Access
10 Citations
7,337 Views
41 Pages

12 September 2020

We study the Hilbert geometry induced by the Siegel disk domain, an open-bounded convex set of complex square matrices of operator norm strictly less than one. This Hilbert geometry yields a generalization of the Klein disk model of hyperbolic geomet...

(This article belongs to the Special Issue Information Geometry III)
  • Article
  • Open Access
1 Citations
2,283 Views
14 Pages

The quantum evolution of wave functions controlled by the spectrum of Lévy random matrices is considered. An analytical treatment of quantum recurrences and revivals in the Hilbert space is performed in the framework of a theory of almost periodic fu...

(This article belongs to the Special Issue Fractional Dynamics: Theory and Applications)
  • Article
  • Open Access
5 Citations
2,652 Views
16 Pages

An Equivalent Form Related to a Hilbert-Type Integral Inequality

  • Michael Th. Rassias,
  • Bicheng Yang and
  • Andrei Raigorodskii

10 July 2023

In the present paper, we establish an equivalent form related to a Hilbert-type integral inequality with a non-homogeneous kernel and a best possible constant factor. We also consider the case of homogeneous kernel as well as certain operator express...

(This article belongs to the Special Issue Differential Equations and Dynamical Systems—Theory and Applications)
  • Article
  • Open Access
4 Citations
2,404 Views
16 Pages

On an Extension of a Hardy–Hilbert-Type Inequality with Multi-Parameters

  • Bicheng Yang,
  • Michael Th. Rassias and
  • Andrei Raigorodskii

30 September 2021

Making use of weight coefficients as well as real/complex analytic methods, an extension of a Hardy–Hilbert-type inequality with a best possible constant factor and multiparameters is established. Equivalent forms, reverses, operator expression with...

(This article belongs to the Special Issue Mathematical Analysis and Analytic Number Theory 2020)
  • Article
  • Open Access
10 Citations
4,028 Views
13 Pages

29 June 2021

In our previous work, by combining the Hilbert scan with the symbol grouping method, efficient run-length-based entropy coding was developed, and high-efficiency image compression algorithms based on the entropy coding were obtained. However, the 2-D...

(This article belongs to the Special Issue Entropy in Image Analysis III)
  • Article
  • Open Access
17 Citations
5,151 Views
15 Pages

Discrete Frames on Finite Dimensional Left Quaternion Hilbert Spaces

  • M. Khokulan,
  • K. Thirulogasanthar and
  • S. Srisatkunarajah

21 February 2017

An introductory theory of frames on finite dimensional left quaternion Hilbert spaces is demonstrated along the lines of their complex counterpart.

(This article belongs to the Special Issue Wavelet and Frame Constructions, with Applications)
  • Article
  • Open Access
7 Citations
6,281 Views
11 Pages

Global Atmospheric Dynamics Investigated by Using Hilbert Frequency Analysis

  • Dario A. Zappalà,
  • Marcelo Barreiro and
  • Cristina Masoller

16 November 2016

The Hilbert transform is a well-known tool of time series analysis that has been widely used to investigate oscillatory signals that resemble a noisy periodic oscillation, because it allows instantaneous phase and frequency to be estimated, which in...

(This article belongs to the Special Issue Applications of Information Theory in the Geosciences)
  • Article
  • Open Access
3 Citations
1,563 Views
13 Pages

21 July 2023

In this paper, we address Hardy–Hilbert-type inequality by virtue of constructing weight coefficients and introducing parameters. By using the Euler–Maclaurin summation formula, Abel’s partial summation formula, and differential mea...

(This article belongs to the Special Issue Recent Trends in Convex Analysis and Mathematical Inequalities)
  • Article
  • Open Access
4 Citations
2,008 Views
16 Pages

Delta Calculus on Time Scale Formulas That Are Similar to Hilbert-Type Inequalities

  • Haytham M. Rezk,
  • Juan E. Nápoles Valdés,
  • Maha Ali,
  • Ahmed I. Saied and
  • Mohammed Zakarya

28 December 2023

In this article, we establish some new generalized inequalities of the Hilbert-type on time scales’ delta calculus, which can be considered similar to formulas for inequalities of Hilbert type. The major innovation point is to establish some dy...

(This article belongs to the Section E: Applied Mathematics)
  • Article
  • Open Access
43 Citations
8,117 Views
27 Pages

7 December 2018

As a classical method to deal with nonlinear and nonstationary signals, the Hilbert–Huang transform (HHT) is widely used in various fields. In order to overcome the drawbacks of the Hilbert–Huang transform (such as end effects and mode mixing) during...

(This article belongs to the Special Issue Intelligent Signal Processing, Data Science and the IoT World)
  • Article
  • Open Access
2 Citations
2,452 Views
16 Pages

29 June 2023

The aim of this article was to provide improved estimates for the (α,β)-norm of a bounded linear operator. In particular, our results enabled the determination of new upper bounds involving both the Berezin number and the Berezin norm of b...

(This article belongs to the Section Mathematical Analysis)
  • Article
  • Open Access
2,068 Views
15 Pages

18 November 2021

In this paper, we establish a new Hardy–Hilbert-type inequality involving parameters composed of a pair of weight coefficients with their sum. Our result is a unified generalization of some Hardy–Hilbert-type inequalities presented in ear...

(This article belongs to the Special Issue Analytic and Geometric Inequalities: Theory and Applications)
  • Article
  • Open Access
19 Citations
2,733 Views
33 Pages

9 August 2024

In dynamical systems, Hilbert spaces provide a useful framework for analyzing and solving problems because they are able to handle infinitely dimensional spaces. Many dynamical systems are described by linear operators acting on a Hilbert space. Unde...

(This article belongs to the Special Issue Variational Problems and Applications, 2nd Edition)

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