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381 Results Found

  • Article
  • Open Access
13 Citations
4,818 Views
12 Pages

Some Properties and Generating Functions of Generalized Harmonic Numbers

  • Giuseppe Dattoli,
  • Silvia Licciardi,
  • Elio Sabia and
  • Hari M. Srivastava

28 June 2019

In this paper, we introduce higher-order harmonic numbers and derive their relevant properties and generating functions by using an umbral-type method. We discuss the link with recent works on the subject, and show that the combinations of umbral and...

(This article belongs to the Special Issue Mathematical Analysis and Analytic Number Theory 2019)
  • Feature Paper
  • Article
  • Open Access
9 Citations
4,003 Views
16 Pages

7 May 2020

The main aim of this paper is to define and investigate a new class of symmetric beta type distributions with the help of the symmetric Bernstein-type basis functions. We give symmetry property of these distributions and the Bernstein-type basis func...

(This article belongs to the Special Issue The 32th Congress of The Jangjeon Mathematical Society (ICJMS2019) will be Held at Far Eastern Federal Universit, Vladivostok Russia)
  • Article
  • Open Access
9 Citations
1,797 Views
18 Pages

Some New Estimates of Fuzzy Integral Inequalities for Harmonically Convex Fuzzy-Number-Valued Mappings via up and down Fuzzy Relation

  • Muhammad Bilal Khan,
  • Aziz Ur Rahman,
  • Abdulwadoud A. Maash,
  • Savin Treanțǎ and
  • Mohamed S. Soliman

10 April 2023

In this article, the up and down harmonically convex fuzzy-number-valued mapping which is a novel kind of harmonically convex fuzzy-number-valued mapping is introduced. In addition, it is highlighted that the new idea of up and down harmonically conv...

  • Article
  • Open Access
1,040 Views
14 Pages

24 December 2024

In this paper, p,q-analogues of the generalized harmonic polynomials and the generalized hyperharmonic polynomials of order ν are defined. We found new sums of these numbers by using combinatorial operations. We also obtained the generating functi...

(This article belongs to the Section B: Mathematics)
  • Article
  • Open Access
2 Citations
2,361 Views
13 Pages

12 September 2024

Utilizing non-overlap windings has emerged as a favourable choice for minimizing electrical machine manufacturing costs, among other benefits. Nevertheless, it is widely acknowledged that these windings exhibit a notable level of harmonic contents in...

(This article belongs to the Special Issue Energy, Electrical and Power Engineering: 3rd Edition)
  • Article
  • Open Access
3 Citations
2,808 Views
15 Pages

29 August 2024

By employing the coefficient extraction method, a class of binomial series involving harmonic numbers will be reviewed through three hypergeometric F12(y2)-series. Numerous closed-form generating functions for infinite series containing binomial coef...

(This article belongs to the Special Issue Polynomials: Theory and Applications, 2nd Edition)
  • Article
  • Open Access
3,587 Views
31 Pages

24 August 2023

A very recent article delved into and expanded the four parametric linear Euler sums, revealing that two well-established subjects—Euler sums and series involving the zeta functions—display particular correlations. In this study, we prese...

(This article belongs to the Special Issue Symmetries of Difference Equations, Special Functions and Orthogonal Polynomials II)
  • Article
  • Open Access
18 Citations
2,960 Views
16 Pages

1 June 2020

Harmonic numbers appear, for example, in many expressions involving Riemann zeta functions. Here, among other things, we introduce and study discrete versions of those numbers, namely the discrete harmonic numbers. The aim of this paper is twofold. T...

(This article belongs to the Special Issue The 33rd International Conference of The Jangjeon Mathematical Society (ICJMS2020) will be held at Hasanuddin University, Makassar, Indonesia)
  • Article
  • Open Access
3 Citations
1,944 Views
11 Pages

q-Analogs of Hn,mrσ and Their Applications

  • Hao Guan,
  • Sibel Koparal,
  • Neşe Ömür and
  • Waseem Ahmad Khan

3 October 2023

In this paper, inspired by recent works, we define q-analogs of Hn,mσ and Hn,mrσ. By implementing them, we obtain new interesting results by taking the derivative or using generating functions.

(This article belongs to the Section C1: Difference and Differential Equations)
  • Article
  • Open Access
6 Citations
2,277 Views
24 Pages

Generalized Harmonically Convex Fuzzy-Number-Valued Mappings and Fuzzy Riemann–Liouville Fractional Integral Inequalities

  • Muhammad Bilal Khan,
  • Aleksandr Rakhmangulov,
  • Najla Aloraini,
  • Muhammad Aslam Noor and
  • Mohamed S. Soliman

28 January 2023

We propose the concept of up and down harmonically convex mapping for fuzzy-number-valued mapping as our main goal in this work. With the help of up and down harmonically fuzzy-number convexity and the fuzzy fractional integral operator, we also show...

(This article belongs to the Section D2: Operations Research and Fuzzy Decision Making)
  • Article
  • Open Access
3 Citations
1,998 Views
13 Pages

19 August 2024

Multiple harmonic-like numbers are studied using the generating function approach. A closed form is stated for binomial sums involving these numbers and two additional parameters. Several corollaries and examples are presented which are immediate con...

  • Article
  • Open Access
4 Citations
5,956 Views
18 Pages

13 November 2019

In this study, two-dimensional numerical simulation was carried out for an oscillatory flow between parallel flat plates having a suddenly expanded section. Governing equations were discretized with the second-order accuracy by a finite volume method...

(This article belongs to the Special Issue Symmetry in Fluid Flow)
  • Article
  • Open Access
2 Citations
3,333 Views
26 Pages

8 April 2022

In this paper, we focus on the higher-order derivatives of the hyperharmonic polynomials, which are a generalization of the ordinary harmonic numbers. We determine the hyperharmonic polynomials and their successive derivatives in terms of the r-Stirl...

(This article belongs to the Section Mathematical Analysis)
  • Feature Paper
  • Article
  • Open Access
7 Citations
3,540 Views
14 Pages

Second Harmonic Revisited: An Analytic Quantum Approach

  • Giovanni Chesi,
  • Matteo M. Wauters,
  • Nadir Fasola,
  • Alessia Allevi and
  • Maria Bondani

24 April 2019

We address the second-harmonic generation process in a quantum frame. Starting with a perturbative approach, we show that it is possible to achieve a number of analytic results, ranging from the up-conversion probability to the statistical properties...

(This article belongs to the Special Issue Quantum Optics for Fundamental Quantum Mechanics)
  • Proceeding Paper
  • Open Access
3 Citations
1,670 Views
11 Pages

15 September 2025

Power inverters are extensively employed in a wide range of applications such as VSD, PV, UPS, and Vehicle-to-Grid systems. Different control topologies are used in power electronic inverters. Of these, PWM and MLVSIs are implemented to minimize the...

(This article belongs to the Proceedings of International Conference on Electronics, Engineering Physics and Earth Science (EEPES 2025))
  • Article
  • Open Access
4 Citations
1,474 Views
12 Pages

Some Addition Theorems for Spin-Weighted Spherical Harmonics

  • Alessandro Monteverdi and
  • Elizabeth Winstanley

19 December 2024

We present some addition theorems for spin-weighted spherical harmonics, generalizing previous results for scalar (spin-zero) spherical harmonics. These addition theorems involve sums over the azimuthal quantum number of products of two spin-weighted...

(This article belongs to the Section Field Theory)
  • Communication
  • Open Access
1 Citations
3,004 Views
11 Pages

Electromechanical Characteristics Analysis under DSISC Fault in Synchronous Generators

  • Yu-Ling He,
  • Ming-Hao Qiu,
  • Xing-Hua Yuan,
  • Xian-Long He and ,
  • Hai-Peng Wang,
  • Meng-Ya Jiang,
  • Chris Gerada and
  • Shu-Ting Wan
  • + 3 authors+ 0 author

This paper studies the electromechanical characteristics of synchronous generators under dynamic stator interturn short circuit (DSISC). First, the air gap magnetic flux density (MFD) of the generator under normal and DSISC fault was obtained. Then,...

(This article belongs to the Special Issue Fault Diagnosis and Health Management of Power Machinery)
  • Article
  • Open Access
16 Citations
4,568 Views
14 Pages

25 April 2019

Novel methods of coherent short-wavelength sources generation require thorough analysis for their further amendments and practical implementations. In this work, we report on the quasi-phase matching (QPM) of high-order harmonics generation during th...

(This article belongs to the Special Issue Ultrafast Laser Pulses)
  • Communication
  • Open Access
3 Citations
1,734 Views
9 Pages

6 November 2024

We report on the theoretical/numerical investigation of simultaneous second- and third-harmonic generation from a single wavelength input in quasi-phase-matched crystals. The presented technique consists of a quadratic crystal with two first-order qu...

(This article belongs to the Section Optoelectronics)
  • Article
  • Open Access
5 Citations
2,033 Views
13 Pages

Curvature Analysis of Seed Silhouettes in Silene L.

  • Emilio Cervantes,
  • José Luis Rodríguez-Lorenzo,
  • José Javier Martín-Gómez and
  • Ángel Tocino

25 June 2023

The application of seed morphology to descriptive systematics requires methods for shape analysis and quantification. The complexity of lateral and dorsal views of seeds of Silene species is investigated here by the application of the Elliptic Fourie...

(This article belongs to the Special Issue Plant Morphology and Function, Geometric Morphometrics, and Modelling: Decoding the Mathematical Secrets of Plants)
  • Article
  • Open Access
2 Citations
2,453 Views
17 Pages

11 September 2022

Integrating the general expression of the generalized harmonic wavelet (GHW)-based spectral representation method (SRM) and the idea of stochastic harmonic function (SHF), a novel stochastic generalized harmonic wavelet (SGHW) method for fully nonsta...

(This article belongs to the Section Civil Engineering)
  • Article
  • Open Access
24 Citations
4,854 Views
19 Pages

27 February 2019

Expanding the number of photovoltaic (PV) systems integrated into a grid raises many concerns regarding protection, system safety, and power quality. In order to monitor the effects of the current harmonics generated by PV systems, this paper present...

(This article belongs to the Section F: Electrical Engineering)
  • Article
  • Open Access
14 Citations
4,846 Views
14 Pages

Complex Attosecond Waveform Synthesis at FEL FERMI

  • Praveen Kumar Maroju,
  • Cesare Grazioli,
  • Michele Di Fraia,
  • Matteo Moioli and ,
  • Dominik Ertel,
  • Hamed Ahmadi,
  • Oksana Plekan,
  • Paola Finetti,
  • Enrico Allaria and
  • Giuseppe Sansone
  • + 31 authors+ 26 authors

20 October 2021

Free-electron lasers (FELs) can produce radiation in the short wavelength range extending from the extreme ultraviolet (XUV) to the X-rays with a few to a few tens of femtoseconds pulse duration. These facilities have enabled significant breakthrough...

(This article belongs to the Special Issue Latest Trends in Free Electron Lasers)
  • Feature Paper
  • Article
  • Open Access
2 Citations
1,610 Views
40 Pages

24 July 2025

The Navier equations are reformulated to be third-order partial differential equations. New anti-Cauchy-Riemann equations can express a general solution in 2D space for incompressible materials. Based on the third-order solutions in 3D space and the...

  • Article
  • Open Access
4 Citations
4,110 Views
15 Pages

Interference-Induced Phenomena in High-Order Harmonic Generation from Bulk Solids

  • Viktor Szaszkó-Bogár,
  • Péter Földi,
  • István Magashegyi and
  • Katalin Varjú

16 April 2019

We consider a quantum mechanical model for the high-order harmonic generation in bulk solids. The bandgap is assumed to be considerably larger than the exciting photon energy. Using dipole approximation, the dynamical equations for different initial...

(This article belongs to the Special Issue Attosecond Science and Technology: Principles and Applications)
  • Article
  • Open Access
19 Citations
3,573 Views
15 Pages

Current Harmonic Aggregation Cases for Contemporary Loads

  • Kamran Daniel,
  • Lauri Kütt,
  • Muhammad Naveed Iqbal,
  • Noman Shabbir and ,
  • Ateeq Ur Rehman,
  • Muhammad Shafiq and
  • Habib Hamam
  • + 2 authors+ 0 author

8 January 2022

Power electronic circuits in modern power supplies have improved the conversion efficiency on the one hand but have also increased harmonic emissions. Harmonic currents from the operation of these units affect the voltage waveforms of the network and...

(This article belongs to the Special Issue Power Transmission and Distribution Equipment and Systems)
  • Article
  • Open Access
2 Citations
1,544 Views
19 Pages

Random PWM Technique Based Two-State Markov Chain for Permanent Magnet Synchronous Motor Control

  • Zhiqiang Wang,
  • Xinyuan Liu,
  • Xuefeng Jin,
  • Guozheng Zhang and
  • Zhichen Lin

30 April 2025

On the basis of the space voltage vector pulse width modulation (SVPWM) technique, the random pulse width modulation (RPWM) technique, which can reduce harmonics, is investigated based on the vector control system of permanent magnet synchronous moto...

(This article belongs to the Topic Advanced Electrical Machines and Drives Technologies, 2nd Edition)
  • Article
  • Open Access
2 Citations
2,724 Views
21 Pages

19 May 2022

This paper presents a comparative simulation study of the operation of various types of drivers dedicated for use in light-emitting diode (LED)-based light stripes. The study comprises an experimentally verified simulation in view of their influence...

(This article belongs to the Section F: Electrical Engineering)
  • Article
  • Open Access
11 Citations
3,312 Views
22 Pages

9 March 2025

The impedance of the harmonic plane in a dual three-phase permanent magnet synchronous motor (DTP-PMSM) is very low, meaning that even small harmonic voltages can induce significant harmonic currents, particularly at the fifth and seventh harmonic fr...

(This article belongs to the Special Issue Advanced Technologies for Electrified Transportation and Robotics)
  • Article
  • Open Access
1,062 Views
22 Pages

17 October 2025

The rim-driven device (RDD) integrates the motor and the impeller, which can achieve shaftless, modular, and integrated operation of the turbomachinery system and has broad application prospects. To reduce the axial length and radial thickness of the...

(This article belongs to the Section Applied Physics General)
  • Article
  • Open Access
10 Citations
3,727 Views
8 Pages

23 January 2019

The paradigmatic models often used to highlight cosmological features of loop quantum gravity and group field theory are shown to be equivalent, in the sense that they are different realizations of the same model given by harmonic cosmology. The loop...

(This article belongs to the Special Issue Progress in Group Field Theory and Related Quantum Gravity Formalisms)
  • Communication
  • Open Access
10 Citations
2,332 Views
9 Pages

Scaling Law of THz Yield from Two-Color Femtosecond Filament for Fixed Pump Power

  • Irina A. Nikolaeva,
  • Daniil E. Shipilo,
  • Nikolay A. Panov,
  • Weiwei Liu and ,
  • Andrei B. Savel’ev and
  • Olga G. Kosareva
  • + 1 author+ 0 author

12 December 2022

In 3D + time numerical simulations, we study the wavelength scaling law for the energy of terahertz (THz) radiation emitted from a two-color femtosecond filament, which forms during cofocusing into air the fundamental and second harmonics of the lase...

(This article belongs to the Special Issue Mid-Infrared Integrated Photonics)
  • Article
  • Open Access
9 Citations
4,753 Views
17 Pages

25 January 2021

The power quality of grid-connected inverters (GCIs) is attracting a lot of attention as the number of distributed generation systems with renewable energy sources are increased. It is well known that the harmonics present in the grid have a lot of d...

(This article belongs to the Section A1: Smart Grids and Microgrids)
  • Article
  • Open Access
446 Views
30 Pages

14 March 2026

Harmonics and interharmonics have a significant impact on the safe operation of power systems, and accurately identifying interharmonics in power systems is the basis of harmonic suppression. The accuracy with which interharmonic components in power...

(This article belongs to the Section B: Mathematics)
  • Article
  • Open Access
2,082 Views
15 Pages

In this paper, in order to effectively reduce the electromagnetic noise of automotive electronic water pumps, a Hybrid Random Carrier Space Vector Pulse Width Modulation Hybrid Random Carrier Space Vector Pulse Width Modulation, (HRCSVPWM) technique...

  • Article
  • Open Access
14 Citations
4,087 Views
16 Pages

27 July 2022

The paper presents investigations and analysis of the parameters of the magnetic part of the equivalent circuit of the inductive CT in the frequencies range from 50 Hz to 5 kHz. Therefore, a measuring circuit used to determine the values of the trans...

(This article belongs to the Special Issue Development of Voltage and Current Transformers in Power System)
  • Article
  • Open Access
3 Citations
2,339 Views
16 Pages

17 April 2024

In this work, we establish some characteristics for a sequence, Aα(n,k), including recurrence relations, generating function and inversion formula, etc. Based on the sequence, we derive, by means of the generating function approach, some transf...

  • Article
  • Open Access
12 Citations
3,498 Views
22 Pages

Performance Analysis of Harmonic-Reduced Modified PUC Multi-Level Inverter Based on an MPC Algorithm

  • Umapathi Krishnamoorthy,
  • Ushaa Pitchaikani,
  • Eugen Rusu and
  • Hady H. Fayek

Renewable and distributed energy generation includes wind turbines, fuel cells, solar cells, and batteries. These distributed energy sources need special power converters in order to connect them to the grid and make the generated power available for...

(This article belongs to the Special Issue Recent Advances and Challenges in Emerging Power Systems)
  • Article
  • Open Access
3 Citations
1,689 Views
19 Pages

Dual-Random Space Vector Pulse Width Modulation Strategy Based on Optimized Beta Distribution

  • Xin Gu,
  • Kunyang Wu,
  • Xuefeng Jin,
  • Guozheng Zhang and ,
  • Wei Chen and
  • Chen Li
  • + 1 author+ 0 author

In the control system of a permanent magnet synchronous motor (PMSM) driven by an inverter, the conventional space vector pulse width modulation (SVPWM) strategy introduces high-frequency current harmonics at the switching frequency and its multiples...

(This article belongs to the Special Issue Advanced Control Techniques for Power Converter and Drives)
  • Article
  • Open Access
11 Citations
6,616 Views
17 Pages

23 April 2017

This paper presents the influences of winding magneto-motive force (MMF) harmonics on the torque characteristics in surface-mounted permanent magnet vernier (SPMV) machines. Based on the magnetic gearing effects, the armature magnetic field of the SP...

(This article belongs to the Section D: Energy Storage and Application)
  • Article
  • Open Access
1 Citations
1,794 Views
15 Pages

Simulation and Experimental Study on Harmonic Optimization of Magnetically Controlled Reactor Based on Multistage Saturated Magnetic Valve Structure

  • Chunhui Liu,
  • Xiyu Yin,
  • Yinfu Bao,
  • Yue Lan and ,
  • Chun Wang,
  • Baichao Chen,
  • Xiaoyue Chen and
  • Yu Wang
  • + 3 authors+ 0 author

6 September 2023

The magnetically controlled reactor adjusts its output capacity based on the principle of magnetic saturation. Due to the iron core working in the saturated region, higher harmonics will be generated in the working current. A large number of harmonic...

  • Article
  • Open Access
4 Citations
2,094 Views
17 Pages

20 February 2025

A grid-forming converter (GFM) controls power output by adjusting the phase angle and amplitude of its output voltage, providing voltage and frequency support to the power system and effectively enhancing system stability. However, it has limitations...

(This article belongs to the Section Power Electronics)
  • Article
  • Open Access
8 Citations
3,032 Views
14 Pages

Geometric Progression of Optical Vortices

  • Victor Kotlyar,
  • Alexey Kovalev,
  • Elena Kozlova,
  • Alexandra Savelyeva and
  • Sergey Stafeev

We study coaxial superpositions of Gaussian optical vortices described by a geometric progression. The topological charge (TC) is obtained for all variants of such superpositions. The TC can be either integer or half-integer in the initial plane. How...

(This article belongs to the Special Issue Light Focusing and Optical Vortices)
  • Article
  • Open Access
15 Citations
5,404 Views
12 Pages

Quantum-Optical Spectrometry in Relativistic Laser–Plasma Interactions Using the High-Harmonic Generation Process: A Proposal

  • Theocharis Lamprou,
  • Rodrigo Lopez-Martens,
  • Stefan Haessler,
  • Ioannis Liontos and ,
  • Subhendu Kahaly,
  • Javier Rivera-Dean,
  • Philipp Stammer,
  • Emilio Pisanty,
  • Marcelo F. Ciappina and
  • Paraskevas Tzallas
  • + 6 authors+ 1 author

Quantum-optical spectrometry is a recently developed shot-to-shot photon correlation-based method, namely using a quantum spectrometer (QS), that has been used to reveal the quantum optical nature of intense laser–matter interactions and connect the...

(This article belongs to the Special Issue Quantum Optics in Strong Laser Fields)
  • Article
  • Open Access
5 Citations
2,015 Views
19 Pages

9 August 2024

Material nonlinearity is explored for the assessment of structural integrity. Crack–wave interactions are of particular interest. The major focus is on higher-order harmonics, generated in propagating shear horizontal (SH) waves. These harmonic...

(This article belongs to the Section Mechanics of Materials)
  • Article
  • Open Access
3 Citations
2,255 Views
12 Pages

The Numerical Solution of the External Dirichlet Generalized Harmonic Problem for a Sphere by the Method of Probabilistic Solution

  • Mamuli Zakradze,
  • Zaza Tabagari,
  • Nana Koblishvili,
  • Tinatin Davitashvili and ,
  • Jose Maria Sanchez and
  • Francisco Criado-Aldeanueva
  • + 1 author+ 0 author

19 January 2023

In the present paper, an algorithm for the numerical solution of the external Dirichlet generalized harmonic problem for a sphere by the method of probabilistic solution (MPS) is given, where “generalized” indicates that a boundary functi...

(This article belongs to the Special Issue Numerical Methods and Applications for Differential Problems)
  • Article
  • Open Access
34 Citations
4,652 Views
14 Pages

27 July 2021

Bolted joints are fundamental to numerous structural components in engineering practice. Nevertheless, their failure or even their loosening can lead to insufficient performance and reduced structural safety. This study presents a theoretical develop...

(This article belongs to the Special Issue Structural Health Monitoring and Nondestructive Evaluation with Ultrasonic Guided Waves)

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