Results 31 to 40 of about 1,811 (151)

Optimum Synthesis of Pencil Beams with Constrained Dynamic Range Ratio

International Journal of Antennas and Propagation, Volume 2022, Issue 1, 2022., 2022
In antenna array design, low dynamic range ratio (DRR) of excitation coefficients is important because it simplifies array’s feeding network and enables better control of mutual coupling. Optimization‐based synthesis of pencil beams allows explicit control of DRR.
Marko Matijascic, Maja Jurisic Bellotti, Mladen Vucic, Goran Molnar, Stefano Selleri   +4 more
wiley   +1 more source

Generalized Auto‐Convolution Volterra Integral Equations: Numerical Treatments

Journal of Mathematics, Volume 2022, Issue 1, 2022., 2022
In this paper, we use the operational Tau method based on orthogonal polynomials to achieve a numerical solution of generalized autoconvolution Volterra integral equations. Displaying a lower triangular matrix for basis functions, the corresponding solution is represented in matrix form, and an infinite upper triangular Toeplitz matrix is used to show ...
Mahdi Namazi Nezamabadi, Saeed Pishbin, Xian-Ming Gu   +2 more
wiley   +1 more source

On Approximation Properties of Fractional Integral for A‐Fractal Function

Mathematical Problems in Engineering, Volume 2022, Issue 1, 2022., 2022
In this paper, the Riemann–Liouville fractional integral of an A‐fractal function is explored by taking its vertical scaling factors in the block matrix as continuous functions from [0,1] to ℝ. As the scaling factors play a significant role in the generation of fractal functions, the necessary condition for the scaling factors in the block matrix is ...
T. M. C. Priyanka, R. Valarmathi, Kishore Bingi, A. Gowrisankar, Waleed Adel   +4 more
wiley   +1 more source

Spectral Collocation Method for Handling Integral and Integrodifferential Equations of n‐th Order via Certain Combinations of Shifted Legendre Polynomials

Mathematical Problems in Engineering, Volume 2022, Issue 1, 2022., 2022
In this study, an accurate and efficient numerical method based on spectral collocation is presented to solve integral equations and integrodifferential equations of n‐th order. The method is developed using compact combinations of shifted Legendre polynomials as a spectral basis and shifted Legendre–Gauss–Lobatto nodes as collocation points to ...
Zineb Laouar, Nouria Arar, Abdellatif Ben Makhlouf, Andres Saez   +3 more
wiley   +1 more source

Dynamic Analysis of Multi‐Stepped Functionally Graded Carbon Nanotube Reinforced Composite Plate with General Boundary Condition

Shock and Vibration, Volume 2021, Issue 1, 2021., 2021
This study presents the multi‐stepped functionally graded carbon nanotube reinforced composite (FG‐CNTRC) plate model for the first time, and its free and forced vibration is analyzed by employing the domain decomposition method. The segmentation technique is employed to discretize the structure along the length direction.
Kwanghun Kim, Songhun Kwak, Yonguk Ri, Yongsong Paek, Wonjin Han, Kumchol Ri, Salvatore Caddemi   +6 more
wiley   +1 more source

A modeling method for vibration analysis of cracked beam with arbitrary boundary condition

Journal of Ocean Engineering and Science, 2018
This paper establishes a cracked Timoshenko beams model to investigate the vibration behavior based on the ultraspherical polynomials. Timoshenko beam theory is applied to model the free vibration analysis of the cracked beam and the numerical results ...
Kwanghun Kim, Sok Kim, Kyongjin Sok, Chanil Pak, Kwangbok Han   +4 more
doaj   +1 more source

New Specific and General Linearization Formulas of Some Classes of Jacobi Polynomials

Mathematics, 2020
The main purpose of the current article is to develop new specific and general linearization formulas of some classes of Jacobi polynomials. The basic idea behind the derivation of these formulas is based on reducing the linearization coefficients which ...
Waleed Mohamed Abd-Elhameed, Afnan Ali
doaj   +1 more source

A method for natural frequency calculation of the functionally graded rectangular plate with general elastic restraints

AIP Advances, 2020
In this study, a unified solution method to obtain the natural frequencies of the functionally graded rectangular plate (FGRP) with general elastic restraints by using ultraspherical polynomials and the Ritz method is presented.
Kwanghun Kim, Kukchol Kim, Cholyong Han, Yonghuan Jang, Poknam Han   +4 more
doaj   +1 more source

Some Orthogonal Polynomials Arising from Coherent States [PDF]

, 2011
We explore in this paper some orthogonal polynomials which are naturally associated to certain families of coherent states, often referred to as nonlinear coherent states in the quantum optics literature.
Akhiezer N I, Andrews G E, Askey R, Chihara T S, Dickinson D J, Erdélyi A, Feller W, Goldberg J, Ismail M E H, Ismail M E H, Klauder J R, Koekoek R Swarttouw R, Mourad E H Ismail, Nevai P, Odzijewicz A, Rainville E D, S Twareque Ali, Sivakumar S, Szegő G, Widder D V   +19 more
core   +1 more source

Least squares approximations of power series

International Journal of Mathematics and Mathematical Sciences, 2006
The classical least squares solutions in C[−1,1] in terms of linear combinations of ultraspherical polynomials are extended in order to estimate power series on (−1,1). Approximate rates of uniform and pointwise convergence are obtained, which correspond
James Guyker
doaj   +1 more source