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Article
Publication date: 1 January 1992

L. Pichon and A. Razek

In the proposed paper a model permitting force analysis in tubular induction devices is presented. A hybrid finite element‐boundary element method using time stepping is…

Abstract

In the proposed paper a model permitting force analysis in tubular induction devices is presented. A hybrid finite element‐boundary element method using time stepping is used to compute the electromagnetic force; this force is introduced in the mechanical equation to determine the acceleration. Numerical values are compared to experimental values.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 11 no. 1
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 1 January 1992

L. PICHON, A. BOURHATTAS and A. RAZEK

We present in this paper an efficient finite element analysis for different types of waveguides . The computations are performed with “edge elements” . These finite…

Abstract

We present in this paper an efficient finite element analysis for different types of waveguides . The computations are performed with “edge elements” . These finite elements avoid all the “spurious modes”, the non‐physical numerical fields obtained from the solution of eigenvalue problems with classical finite elements formulations.Both dielectric‐loaded waveguides and ridged waveguides (waveguides with sharp edges) are analyzed. Comparisons of our results with previously published ones show theaccuracy of the numerical technique.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 11 no. 1
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 12 July 2011

M.K. Smail, L. Pichon, M. Olivas, F. Auzanneau and M. Lambert

Aging wiring in cars, aircraft, trains and other transportation means is identified as a critical security area. The purpose of this paper is to develop a new methodology…

Abstract

Purpose

Aging wiring in cars, aircraft, trains and other transportation means is identified as a critical security area. The purpose of this paper is to develop a new methodology for wire diagnosis allowing the detection, localization and characterization of the fault in wiring network.

Design/methodology/approach

The direct problem (propagation along the cables) is modelled by RLCG circuit parameters and the finite difference time domain method. This model provides a simple and accurate method to simulate time domain reflectometry (TDR) responses. Genetic algorithms are combined with this wire propagation model to solve the inverse problem and to deduce physical information's about defects from the reflectometry response.

Findings

The results show the applicability of an inverse procedure dedicated to TDR for the localization and characterization of defects in simple wires and faulty wiring networks. With experimental results, the paper demonstrates the accuracy which can be provided for wire diagnosis.

Practical implications

The work provides an efficient tool for the diagnosis of embedded wire networks.

Originality/value

In this paper, a new method is developed and applied to detect, characterize and localize the defects in wiring networks: an inverse procedure is introduced for wire diagnosis. The presented methodology is applied for complex network structures and with measurement data.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 30 no. 4
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 13 July 2010

T. Hacib, H. Acikgoz, Y. Le Bihan, M.R. Mekideche, O. Meyer and L. Pichon

The dielectric properties of materials (complex permittivity) can be deduced from the admittance measured at the discontinuity plane of a coaxial open‐ended probe. This…

Abstract

Purpose

The dielectric properties of materials (complex permittivity) can be deduced from the admittance measured at the discontinuity plane of a coaxial open‐ended probe. This implies the implementation of an inversion procedure. The purpose of this paper is to develop a new non‐iterative inversion methodology in the field of microwave characterization allowing reducing the computation cost comparatively to iterative procedures.

Design/methodology/approach

The inversion methodology combines the support vector machine (SVM) technique and the finite element method (FEM). The SVM are used as inverse models. They show good approximation and generalization capabilities. FEM allows the generation of the data sets required by the SVM parameter adjustment. A data set is constituted of input (complex admittance and frequency) and output (complex permittivity) pairs.

Findings

The results show the applicability of SVM to solve microwave inverse problems instead of using traditional iterative inversion methods which can be very time‐consuming. The experimental results demonstrate the accuracy which can be provided by the SVM technique.

Practical implications

The paper allows extending the capability of microwave characterization cells developed at Laboratoire de Génie Électrique de Paris.

Originality/value

A new inversion method is developed and applied to microwave characterization. This new concept introduces SVM in the context of microwave characterization. SVM results and iterative inversion procedure results are compared in order to evaluate the effectiveness of the developed technique.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 29 no. 4
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 1 December 1996

A. Saadi and L. Pichon

Presents a new method to compute simultaneously the near and the far field in electromagnetic 3D scattering problems. In this approach a bounded spherical domain contains…

Abstract

Presents a new method to compute simultaneously the near and the far field in electromagnetic 3D scattering problems. In this approach a bounded spherical domain contains all the inhomogeneous objects and divides the whole space into two different regions. In both regions the field is expressed as a linear expansion with the same unknown coefficients. Gives the field as an exact infinite expansion of vector spherical harmonics in the outer region. Computes the basis functions using finite elements in the inner region. Finally, obtains the coefficients of the two expansions by matching the inner and the outer fields on the spherical interface.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 15 no. 4
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 1 July 2006

Y. Choua, Y. Le Bihan and L. Pichon

The aim of this paper is to calculate the impedance of a loop antenna, etched on a dielectric substrate, over a wide frequency band using finite element method (FEM).

Abstract

Purpose

The aim of this paper is to calculate the impedance of a loop antenna, etched on a dielectric substrate, over a wide frequency band using finite element method (FEM).

Design/methodology/approach

The electromagnetic analysis of the global structure is performed with a full wave finite element formulation. In this work, two methods for the calculation of the impedance of the antenna are presented: receiving and transmitting mode. The results obtained are compared with boundary element method (BEM).

Findings

The paper finds that from the FEM analysis an equivalent circuit of a rectenna was obtained over a wide frequency band. A good agreement was obtained with a BEM approach in the case of an air‐like substrate. A dielectric substrate was considered. Such a configuration is more difficult to deal with BEM and makes the FEM attractive.

Practical implications

The equivalent circuit allows a global circuit simulation of the whole rectenna (antenna, rectifying diodes and load). This simulation can be achieved using spice simulator for example.

Originality/value

This paper shows the potentiality of the FEM to simulate an antenna over a broad band frequency. Two methods for the calculation of the impedance of the antenna are presented. It is addressed to R&D designers in the microwave area.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 25 no. 3
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 1 June 2000

P.Di Barba

Introduces the fourth and final chapter of the ISEF 1999 Proceedings by stating electric and magnetic fields are influenced, in a reciprocal way, by thermal and mechanical…

Abstract

Introduces the fourth and final chapter of the ISEF 1999 Proceedings by stating electric and magnetic fields are influenced, in a reciprocal way, by thermal and mechanical fields. Looks at the coupling of fields in a device or a system as a prescribed effect. Points out that there are 12 contributions included ‐ covering magnetic levitation or induction heating, superconducting devices and possible effects to the human body due to electric impressed fields.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 19 no. 2
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 1 February 1991

L. PICHON and A. RAZEK

This paper presents a hybrid finite element — boundary element method for the steady state thermal analysis of energy installations. The coupling of the two techniques is…

Abstract

This paper presents a hybrid finite element — boundary element method for the steady state thermal analysis of energy installations. The coupling of the two techniques is presented: finite elements are used in a bounded region containing thermal sources while the complementary domain is treated with boundary elements. With such a combination the number of unknowns is reduced and an accurate prediction of temperature is obtained. As an example, the temperature rise is computed for the case of three power cables laid in a thermal backfill: the finite element method (FEM) is used for the cables and the backfill while the homogeneous soil is taken into account with the boundary element method (BEM).

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 10 no. 2
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 29 April 2021

Natália Peroni Pellin, Alex Weymer, Leila Andressa Dissenha and Márcio André Leal Bauer

The aim of this article was to analyze how the presence of the elements that constitute organizational links are related to sensemaking in a cooperative system of medical work.

Abstract

Purpose

The aim of this article was to analyze how the presence of the elements that constitute organizational links are related to sensemaking in a cooperative system of medical work.

Design/methodology/approach

A content analysis was conducted following interviews with the managers of the cooperative, which is a member of the Brazilian cooperative system and one of the largest in the world. This analysis enabled the systematization of the categories that were identified through the coding of responses, aided by Atlas.ti 8.0 software.

Findings

After the analysis, it was possible to resize the constitutive elements identified in the specialized literature into three categories: identification, cooperation and recognition. The proposed resizing does not preclude the presence of the constitutive elements identified in the analysis, but it evidences the presence of these elements in a contextualized manner, suggesting a model of an organic organizational link that is dependent on the relationship between subject–object (organization), in which the different perceptions of meanings affect identification, and this can strengthen or weaken the link in a constant process of resignification.

Originality/value

With regard to its theoretical relevance, the work helps to bring concepts related to organizational links and sensemaking closer together as a process in the realm of intersubjectivity. This provides evidence of the presence of constituent elements of ties in a contextualized manner, demonstrating that the interpretation of managers aids sensemaking in a process of circularity and resignification.

Details

Qualitative Research in Organizations and Management: An International Journal, vol. 16 no. 2
Type: Research Article
ISSN: 1746-5648

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Article
Publication date: 1 April 1995

S. Gratkowski, L. Pichon and A. Razek

A basic difficulty encountered in applying the finite element method to unbounded wave problems is that the domain in which the field is to be computed is unbounded, while…

Abstract

A basic difficulty encountered in applying the finite element method to unbounded wave problems is that the domain in which the field is to be computed is unbounded, while finite element models are of finite size. There are several ways to overcome this difficulty. The widely used method is to truncate the finite element model at a finite position and apply suitable boundary conditions there. The relevant boundary conditions must absorb the outgoing wave and have been called absorbing boundary conditions (ABC's).

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 14 no. 4
Type: Research Article
ISSN: 0332-1649

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