International Journal of Applied Electromagnetics and Mechanics - Volume 28, issue 1-2

Article Type: Editorial

Abstract: Preface to the ISEM 2007 special issue.

DOI: 10.3233/JAE-2008-948

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 28, no. 1-2, pp. 1-2, 2008

Authors: Rondot, Loïc | Mazauric, Vincent | Delannoy, Yves | Meunier, Gerard

Article Type: Research Article

Abstract: A magnetodynamic formulation is developed using the Finite Volume Method to address specific issues in multiphysics involved in circuit breaker modeling. The principles of Finite Volume Method and multiphysics coupling method are described. The magnetostatic formulation is validated through two examples by comparison with two analytical solutions. Both problems are expressed within current based T_{0} − � formulation which differs drastically from other developments given in the context of Finite …Volume Method. Finally a circuit breaker simulation is carried out within a magnetostatic formulation. Show more

Keywords: Plasma, ferromagnetic, Finite Volume Method

DOI: 10.3233/JAE-2008-949

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 28, no. 1-2, pp. 3-9, 2008

Authors: Chen, Duo | Shanker, B. | McGough, Robert J.

Article Type: Research Article

Abstract: Analytical expressions are derived for fast calculations of 3D potential integrals. These fast calculation methods remove the singularities from potential integrals and thus achieve very fast convergence with a very small number of sample points. The simulation results show that for a given number of significant digits, the fast calculation method always converges much faster than the singularity cancellation method for the prism domain.

Keywords: Potential integral, 3D FNM, singularity cancellation

DOI: 10.3233/JAE-2008-950

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 28, no. 1-2, pp. 11-15, 2008

Authors: Badics, Zsolt | Matsumoto, Yoshihiro

Article Type: Research Article

Abstract: An efficient strategy is described for the solution of time-harmonic electromagnetic and elastic wave problems. The strategy is based on the framework of the discontinuous Galerkin (DG) method, thereby using approximation bases that are locally conservative. Additionally, in the Trefftz DG method each approximation function satisfies the underlying partial differential equation in each finite element. The Trefftz DG method is similar to the ultra weak variational formulation (UWVF) but the local bases are …constructed differently. Electromagnetic wave, eddy current and elastic wave problems are solved in order to analyze the performance of the method. The ultrasonic testing (UT) example is a two-dimensional elastic wave model of the Inconel welding area in reactor vessels. Show more

Keywords: Discontinuous Galerkin method, Trefftz method, computational electromagnetics, computational UT, Inconel welding NDE

DOI: 10.3233/JAE-2008-951

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 28, no. 1-2, pp. 17-24, 2008

Authors: Cundeva-Blajer, Marija | Arsov, Ljupco

Article Type: Research Article

Abstract: In the paper an advanced CAD (computer aided design) methodology for measurement uncertainties estimation of a combined current-voltage instrument transformer (CCVIT) will be presented. The metrological parameters of the CCVIT are influenced by many variables, mostly introduced by the non-linearity of the very complex CCVIT electromagnetic system. The electromagnetic field distribution in the CCVIT 3D domain will be determined by using an original program package FEM-3D (finite element method) developed at the Faculty of …Electrical Engineering and Information Technologies (FEIT)-Skopje. The FEM results will be used for further metrological optimal design of the CCVIT by using the genetic algorithm. The FEM-3D estimated CCVIT metrological uncertainties will be experimentally verified through actual test results recorded in a laboratory. Show more

Keywords: Instrument transformer, finite element method, genetic algorithm

DOI: 10.3233/JAE-2008-952

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 28, no. 1-2, pp. 25-31, 2008

Authors: Ido, Yasushi | Nakagawa, Hideyuki | Kunitomo, Takahiro | Kawai, Hideki

Article Type: Research Article

Abstract: Flow field in a thin layer of magnetic fluid under traveling magnetic field is investigated using the ALE type of GSMAC finite element method. Numerical results are qualitatively agree well with the experimental results reported by H. Kikura [1]. Relation between flow field and volume transportation of fluid is reported. It is shown that the surface velocity is maximized at the certain depth of magnetic fluid layer in case of low frequency of traveling magnetic field.

Keywords: Magnetic fluid, traveling magnetic field, GSMAC, finite element method, surface velocity

DOI: 10.3233/JAE-2008-953

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 28, no. 1-2, pp. 33-39, 2008

Authors: Leite, Jean Vianei | Benabou, Abdelkader | Sadowski, Nelson | Menach, Yvonnick Le | Clenet, Stéphane | Da Silva Jr., Pedro Armando

Article Type: Research Article

Abstract: This work deals with the implementation of a vector hysteresis model in a 2D finite element code with vector potential formulation. The inverse Jiles-Atherton vector hysteresis model is used to describe the magnetic behavior law. This model allows to write naturally the differential reluctivity tensor which can be directly applied to the field calculation equations. The proposed implementation is then validated with a numerical model of a rotational single sheet tester and comparison with the measurements.

Keywords: Magnetic hysteresis modeling, finite elements, magnetic materials

DOI: 10.3233/JAE-2008-954

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 28, no. 1-2, pp. 41-47, 2008

Authors: VanderLaan, Donald J. | Khurshid, Khawar | Ireland, James J. | Jimenez-Krassel, Fermin | McGough, Robert J.

Article Type: Research Article

Abstract: Important reproductive information can be determined by analyzing the follicles in an ultrasound scan of the ovary. The currently used process requires an expert to manually mark and measure the size of the follicles. Manual analysis is time-consuming and often conflicting. A robust computer assisted approach to automatically detect and quantify follicles would improve both the efficiency and accuracy of the process. The multi-step algorithm presented involves coarse ovarian segmentation, follicle detection, and post …processing using level sets to automatically determine follicle boundaries. In comparison with expert evaluations, experiments on bovine ovarian images show encouraging results. The algorithm correctly detected approximately 65% of the ovarian follicles. Show more

Keywords: Ultrasound, segmentation, active contours, level sets

DOI: 10.3233/JAE-2008-955

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 28, no. 1-2, pp. 49-54, 2008

Authors: Shane, Steven | Kelly, James F. | McGough, Robert J.

Article Type: Research Article

Abstract: A geometric approach is developed to calculate the region of support for a focused linear array of circular pistons in a lossless medium. Equations are derived describing the boundaries of the region of support for a single piston. The model is expanded to examine the lossy case utilizing a Gaussian distribution to model attenuation in a viscous medium. These results are verified using the Fast Nearfield Method, and the numerical error is evaluated.

DOI: 10.3233/JAE-2008-956

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 28, no. 1-2, pp. 55-59, 2008

Authors: Raguin, L. Guy | Majumdar, Shantanu | Udpa, Satish S.

Article Type: Research Article

Abstract: Diffusion-weighted imaging (DWI) has been shown to provide valuable structural information in biological fibrous soft tissues, such as the central and peripheral nervous system and skeletal muscle, based on the acquisition of a series of images that sample q-space. Existing q-space sampling schemes have been compared using several metrics based on diffusion tensor imaging (DTI), which models the restricted diffusion inside fibres as anisotropic unrestricted diffusion. Otherwise, sampling schemes have been optimized …using model-independent cost functions. We propose using a model-based framework that connects the experimental noise, the uncertainty in the estimation of the model parameters, and the q-space sampling schemes together, to obtain model-based optimal sampling schemes for the case when the fibre orientation is known a priori to be within a finite region. We apply and validate this framework for the recently proposed quantitative analysis of q-space MRI data (QUAQ) model. Show more

Keywords: Magnetic resonance imaging, diffusion, optimization

DOI: 10.3233/JAE-2008-957

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 28, no. 1-2, pp. 61-67, 2008