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Your search keyword '"Ida, Nathan"' showing total 11 results
Start Over Author "Ida, Nathan" Topic finite element method
11 results on '"Ida, Nathan"'

6. Finite element analysis and design of beam steering devices with global control.

Author

Alkhateeb, Osama, Hossain, A.N.M. Shahriyar, Tsukerman, Igor, and Ida, Nathan

Subjects
FINITE element method, BEAM steering, TELECOMMUNICATION satellites, REMOTE-sensing images
Abstract

Purpose: This paper aims to design metaguide- or metasurface-based compact inexpensive beam-steering devices, which play an important role in modern cellular networks, radar imaging and satellite communication. Design/methodology/approach: This paper uses finite element analysis to study, design and optimize arrays of resonating elements as beam steering devices. The first set of such devices involves metamaterial-based apertures fed by a waveguide, tunable via the permittivity of the host material. In the second approach, dynamic beam steering is effected by alternating between two or more waveguide feeds. Findings: Particular examples show how the direction of the main lobe of the radiated beam can be reliably switched by approximately 30° in one of the quadrants by changing a single global control parameter within a very reasonable range. Research limitations/implications: The findings pave the way for the design and fabrication of inexpensive compact beam steering devices. This study anticipates that the proposed designs can be further improved and fine-tuned using "heavy duty" optimization packages. Originality/value: In many published designs of similar beam-steering devices, the radiation pattern of an array of resonating elements is controlled by complex circuitry, so that each radiating element is tuned separately. In contrast with these existing approaches, the designs rely just on a simple global control parameter. [ABSTRACT FROM AUTHOR]

Published
2022
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7. Thickness measurement of metal coating above moving conductive plate by rectangular coil and electromagnetic method

Author

Ida Nathan, Zhang Siquan, and Wu Weihua

Subjects
Materials science, business.industry, Physics::Medical Physics, engineering.material, Finite element method, Magnetic field, Conductor, Coating, Electromagnetic coil, Nondestructive testing, engineering, Electronic engineering, Composite material, business, Electrical impedance, Electrical conductor
Abstract

The electromagnetic NDT method plays an important role in a nondestructive material test. In testing conductive structures, the rectangular coil is more useful than a circular coil due to its asymmetric characteristic. One rectangular coil places above and parallel to the moving conductive plate with metal coating, serving as exciting and sensing coil to measure the thickness of the metal coating. The accurate theoretical expression of the coil impedance variation is derived by analytical method, and the influences of the excitation frequency and the moving speed of conductor to the coating thickness measurement are analyzed. The analytical calculation results are verified with the implementation of finite element method.

Published
2015

8. Data-Driven Arbitrary Polynomial Chaos for Uncertainty Quantification in Filters.

Author

Alkhateeb, Osama J. and Ida, Nathan

Subjects
*POLYNOMIAL chaos, *MONTE Carlo method, *FINITE element method, *APPROXIMATION theory, *MATHEMATICAL models
Abstract

A non-intrusive arbitrary polynomial chaos (aPC) method is applied to a problem of a band-stop filter with geometrical imperfections. The construction of aPC scheme only requires evaluating a finite number of moments, and does not involve assigning analytical probability density functions for the uncertain parameters of a stochastic model. Therefore, aPC is well suited for applications where the uncertain parameters are represented by raw data samples, as with the case of experimental measurements. The numerical examples show that the aPC approach is accurate even with a limited number of input samples. [ABSTRACT FROM AUTHOR]

Published
2018

9. A systematic approach to the concept of surface impedance boundary conditions

Author

Rienzo Luca Di, Sergey Yuferev, and Ida Nathan

Subjects
Nonlinear system, Mathematical optimization, Finite-difference time-domain method, General Earth and Planetary Sciences, Applied mathematics, Surface impedance, Boundary value problem, Finite element method, General Environmental Science, Mathematics
Abstract

This paper discusses the general issues, derivation, implementation and applications of Surface Impedance Boundary Conditions (SIBCs) in the time- and frequency-domains. A comprehensive approach based on perturbation methods leads to SIBCs of desired order of approximation as well as systematic implementation within existing formulations for linear and nonlinear media. The approach described here also allows evaluation of errors and appropriateness of SIBCs for specific applications. A suite of SIBCs is proposed, suitable for use in a wide range of practical applications and formulations including FEM, FDTD, FIT and BEM. A general toolbox that can be used for derivation of SIBCs for the users specific formulation and application has been developed and is described here as well. .

Published
2009

10. Modeling of velocity effects in eddy current applications.

Author

Ida, Nathan

Subjects
*EDDY currents (Electric), *FINITE element method, *SPEED
Abstract

Focuses on a study which proposed the use of finite element formulation to investigate the effect of velocity on moving sources in eddy current applications. Approximation of finite element; Mesh refinement and upwinding; Evaluation of the formula.

Published
1988
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11. Three-Dimensional p-Adaptive Computation of Electrostatic Force and Energy.

Author

Jian-She Wang and Ida, Nathan

Subjects
*ELECTROSTATICS, *FORCE & energy, *FINITE element method, *MATHEMATICAL models
Abstract

Provides information on a study which examined a p-adaptive finite element method for electrostatic force and energy computation based on the constitutive error criterion. Formulation and constitutive error; Refinement strategy in polyhedral mesh; Validation and micro-electro-mechanical systems application.

Published
2000
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