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Article
Publication date: 1 June 2000

A. Savini

Gives introductory remarks about chapter 1 of this group of 31 papers, from ISEF 1999 Proceedings, in the methodologies for field analysis, in the electromagnetic…

Abstract

Gives introductory remarks about chapter 1 of this group of 31 papers, from ISEF 1999 Proceedings, in the methodologies for field analysis, in the electromagnetic community. Observes that computer package implementation theory contributes to clarification. Discusses the areas covered by some of the papers ‐ such as artificial intelligence using fuzzy logic. Includes applications such as permanent magnets and looks at eddy current problems. States the finite element method is currently the most popular method used for field computation. Closes by pointing out the amalgam of topics.

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 January 1985

JAN SIKORA, JERZY SKOCZYLAS, JAN SROKA and STANISLAW WINCENCIAK

This paper discusses an electrostatic, homogeneous field in a uniform two‐dimensional domain with Neumann's boundary conditions. The boundary conditions are known only at…

Abstract

This paper discusses an electrostatic, homogeneous field in a uniform two‐dimensional domain with Neumann's boundary conditions. The boundary conditions are known only at some segments of the boundary. The synthesis is understood as the computation of the remaining boundary conditions which would ensure the required potential distribution in some subdomains within the boundary. The introduction of a single‐layer potential leads to Fredholm's equation of the second order. Stepwise approximation of the source distribution along the boundary rearranges Fredholm's equation and the requirements concerning the single layer potential distribution. It leads to a matrix equation with a rectangular coefficient matrix. In order to solve approximately this equation, in the sense of the least squares minimization, the singular value decomposition (SVD) method is used. The choice of subdomains with determined potential distribution influences significantly the conditioning of the equation. Easy selection of an acceptable solution among all possible solutions proves the suitability of the SVD method in the above problem. The numerical experiments reported in the paper are a good illustration of this.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 4 no. 1
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 1 February 1998

R. Sikora and S. Gratkowski

The Faculty of Electrical Engineering at the Technical University of Szczecin, Poland, provides education and training at a technical level as well as up to the Master of…

Abstract

The Faculty of Electrical Engineering at the Technical University of Szczecin, Poland, provides education and training at a technical level as well as up to the Master of Science degree. Electromagnetics and applications are fundamental to electrical engineering and play an important role in the faculty’s curriculum. Because of the vast amount of material to be covered, the essential problem is an appropriate choice of topics. Special care needs to be taken while teaching basic concepts and principles, but nowadays also computer‐aided methods. After many years of experience in teaching electromagnetics the authors have proposed new programmes for teaching the subject within the courses offered by the faculty. Some aspects of these programmes are described in the paper.

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COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 17 no. 1
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 1 August 1998

J.K. Sykulski, A. Krawczyk and S. Wiak

The paper presents a historical review, the state of the art and recent advances in the field of computational electromagnetics at leading universities and research…

Abstract

The paper presents a historical review, the state of the art and recent advances in the field of computational electromagnetics at leading universities and research institutes in Poland. Contributions made by Polish scientists to the development of fundamental electromagnetism, as well as to computational methods, are emphasized, and some conclusions are drawn regarding expected future developments.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 17 no. 4
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 5 October 2015

Hanan Ibrahim Mudawi and Mohamed Osman Idris

The purpose of this paper is to investigate the ability of four microorganisms to reduce disease infection of root lesion nematode (Pratylenchus spp.) and Fusarium spp…

Abstract

Purpose

The purpose of this paper is to investigate the ability of four microorganisms to reduce disease infection of root lesion nematode (Pratylenchus spp.) and Fusarium spp. the causal agent of wilt/root-rot disease complex in chickpea.

Design/methodology/approach

A pot experiment was conducted for three consecutive winter seasons. A completely randomized design with five replicates was adopted. Two Bacillus isolates and Trichoderma harzianum and T. viride and their combinations were applied in infected soil. The effect on plant growth parameters, disease incidence and severity, root necrosis, weight of shoot and root, nematode population density and reproductive index were assessed.

Findings

The applications significantly (p=0.05) reduced the wilt/root-rot diseases complex. The reduction was attributed to the decline of the population density of nematodes in soil and root, and the suppression of the disease complex compared to controls, represented by reproductive index and the disease intensity index. Combinations were better than individual inoculation. The use of Bacillus isolate B3 and T. harzianum increased the number of flowers by 88.34 per cent. Reduction in the severity of root necrosis was in the range of 2.22-5.55 within a scale of 1-10. These findings indicate the significance of utilizing local bioagents for control of wilt/root-rot disease complex in chickpea plants.

Originality/value

The microorganisms used in this study are indigenous.

Details

World Journal of Science, Technology and Sustainable Development, vol. 12 no. 4
Type: Research Article
ISSN: 2042-5945

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Article
Publication date: 1 January 1993

J. SIKORA, W. KWIATKOWSKI and H. KRAUS

A new method of designing electromagnetic devices especially high‐voltage ones, is presented. As a result of applying a sequential quadratic programing algorithm and a…

Abstract

A new method of designing electromagnetic devices especially high‐voltage ones, is presented. As a result of applying a sequential quadratic programing algorithm and a very effective algorithm for non‐linear minimax optimization, a flexible method for computer aided design of high‐voltage and semiconductor devices has been obtained. The minimax algorithm is based on a successive linear approximation of the functions defining the problem. In each iteration step these functions are computed with the aid of the finite element method. The resulting linear subproblems are solved in the minimax sense subject to the linear equality and inequality constraints. Applications of these two methods for the designing some parts of the high‐voltage devices are presented.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 12 no. 1
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 21 August 2018

Ryszard Sikora and Stanislaw Pawłowski

This paper aims to evaluate the possibilities of fractional calculus application in electrical circuits and magnetic field theories.

Abstract

Purpose

This paper aims to evaluate the possibilities of fractional calculus application in electrical circuits and magnetic field theories.

Design/methodology/approach

The analysis of mathematical notation is used for physical phenomena description. The analysis aims to challenge or prove the correctness of applied notation.

Findings

Fractional calculus is sometimes applied correctly and sometimes erroneously in electrical engineering.

Originality/value

This paper provides guidelines regarding correct application of fractional calculus in description of electrical circuits’ phenomena. It can also inspire researchers to find new applications for fractional calculus in the future.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 37 no. 4
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 31 December 2020

Tomasz Rymarczyk, Konrad Kania, Michał Gołąbek, Jan Sikora, Michał Maj and Przemysław Adamkiewicz

The purpose of this study is to develop a reconstruction and measurement system for data analysis using ultrasonic transmission tomography. The problem of reconstruction…

Abstract

Purpose

The purpose of this study is to develop a reconstruction and measurement system for data analysis using ultrasonic transmission tomography. The problem of reconstruction from the projection is encountered in practical implementation, which consists in reconstructing an image that is an estimation of an unknown object from a finite set of projection data. Reconstructive algorithms used in transmission tomography are based on linear mathematical models, which makes it necessary to process non-linear data into estimates for a finite number of projections. The application of transformation methods requires building a mathematical model in which the projection data forming the known and unknown quantities are functions with arguments from a continuous set of real numbers, determining the function describing the unknown quantities sought in the form of inverse relation and adapting it to operate on discrete and noisy data. This was done by designing a tomographic device and proprietary algorithms capable of reconstructing two-dimensional images regardless of the size, shape, location or number of inclusions hidden in the examined object.

Design/methodology/approach

The application consists of a device and measuring sensors, as well as proprietary algorithms for image reconstruction. Ultrasonic transmission tomography makes it possible to analyse processes occurring in an object without interfering with the examined object. The proposed solution uses algorithms based on ray integration, the Fermat principle and deterministic methods. Two applications were developed, one based on C and implemented on the embedded device, while the other application was made in Matlab.

Findings

Research shows that ultrasonic transmission tomography provides an effective analysis of tested objects in closed tanks.

Research limitations/implications

In the presented technique, the use of ultrasonic absorption wave has been limited. Nevertheless, the effectiveness of such a solution has been confirmed.

Practical implications

The presented solution can be used for research and monitoring of technological processes.

Originality/value

Author’s tomographic system consisting of a measuring system and image reconstruction algorithms.

Details

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

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Article
Publication date: 10 April 2007

Andrzej Brykalski and Tomasz Rogala

The goal of the paper is to introduce a new method of obtaining equivalent dynamic model of electromagnetic field quantities. Proposed algorithm allows approximation of…

Abstract

Purpose

The goal of the paper is to introduce a new method of obtaining equivalent dynamic model of electromagnetic field quantities. Proposed algorithm allows approximation of the frequency and step response by a simple inertial element model, with adjustable rank and delay. The values of the model parameters may be also used to describe the dynamics of considered system.

Design/methodology/approach

The dynamics of interesting field quantity in certain space location may be represented by an equivalent model of inertial element. Parameters of the model are identified using the solution of the problem in quasi‐stationary conditions for very limited number of excitation frequencies. These solutions are further used to build a matching approximation of real frequency response function (FRF).

Findings

The proposed method allows fast approximation of transient states of linear vector field. It may be useful with fast and relatively precise estimation of dynamic parameters of the electromagnetic field, e.g. in screening and eddy current problems.

Research limitations/implications

The main limitation of the method is the assumption of linearity of the problem. However, many practical tasks similar to the examples presented in the paper can be considered highly linear.

Practical implications

The main advantage of the method is that it allows fast estimation of the field dynamics without either solving the problem for whole range of frequencies or computing the transient state in time domain. It does not need the access to the original mass and stiffness matrices. Therefore, it may be used with commercial FEM software, which usually restricts access to its internal data.

Originality/value

The method is based on well known concept of moments, but the use of existing stationary FEM solutions for approximating transient states is a novel approach. Proposed procedure may be easily automated for the simulation environments with scripting capabilities.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 26 no. 2
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 4 July 2016

Tomasz Chady, Ryszard Sikora, Mariusz Szwagiel, Bogdan Grzywacz, Leszek Misztal, Pawel Waszczuk, Michal Szydlowski and Barbara Szymanik

The purpose of this paper is to describe a multisource system for nondestructive inspection of welded elements exploited in aircraft industry developed in West Pomeranian…

Abstract

Purpose

The purpose of this paper is to describe a multisource system for nondestructive inspection of welded elements exploited in aircraft industry developed in West Pomeranian University of Technology, Szczecin in the frame of CASELOT project. The system task is to support the operator in flaws identification of welded aircraft elements using data obtained from X-ray inspection and 3D triangulation laser scanners.

Design/methodology/approach

For proper defects detection a set of special processing algorithms were developed. For easier system exploitation and integration of all components a user friendly interface in LabVIEW environment was designed.

Findings

It is possible to create the fully independent, intelligent system for welds’ flaws detection. This kind of technology might be crucial in further development of aircraft industry.

Originality/value

In this paper a number of innovative solutions (new algorithms, algorithms’ combinations) for defects’ detection in welds are presented. All of these solutions are the basis of presented complete system. One of the main original solution is a combination of the systems based on 3D triangulation laser scanner and X-ray testing.

Details

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 35 no. 4
Type: Research Article
ISSN: 0332-1649

Keywords

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