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The electric stimulation of the vagus nerve is used to obtain therapeutic results in epilepsy, depression and Alzheimer diseases. The purpose of this paper is to show numerical model of stimulation, focusing on the mathematical approach to modeling a phenomenon of neural cells activation and its propagation in the nerve.

The paper presents a model based on the bidomain theory. It uses two continuous, averaged domains which depict the intra‐ and extra‐cellular domains and are connected with the membrane ionic currents. The numerical model uses 3D cylindrical model approximating the anatomical shape of the neck. The simulator is based on a time domain finite element method.

The presented approach allows to model the discrete behaviour of the membrane potential in the macroscopic, realistic model of the nerve. The validation of the parameters with the velocity of activation propagations suggests the strong disscussion on physical interpretation to the bidomain theory parameters. To obtain realistic results the parameters needed to be unrealistic.

The paper presents the combination of bidomain model of neural tissue with the time domain finite element method along with the atributes of bidomain model for realistic modeling of the process of propagtion of activation.

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.

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).

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.

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.

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.

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.

The increase of the accuracy of a mathematical model of hysteresis by the choice of the optimum saturation curve for a given material.

Hysteresis loops of typical soft magnetic materials are approximated with the help of the Taka´cs magnetization model using different saturation curves. The quality of approximations is determined by the deviation of computed magnetic induction amplitudes, iron losses, apparent remanences and coercivities from the measured values.

By the proper choice of saturation curve, the relative inaccuracy of approximations can be reduced with reference to the original model based on tangent hyperbolic function.

The accuracy of approximations worsens close to saturation because of the excessive rise of magnetization due to the linear term of the model. This effect should be minimized by the application of complex saturation curves using greater number of parameters.

Owing to the convenient analytical form and increased accuracy, the model equations can be used in simpler practical evaluations of hysteresis effects and for teaching purposes.

Presented form of model equations enables approximation of hysteresis loops and the evaluation of main characteristics of magnetic materials on the basis of any saturation curve.

The purpose of this paper is to present a 3D model of deep welding of dissimilar metals and to show how to model the electron beam deflection due to thermoelectric fields caused by temperature gradients in some dissimilar metals (Seebeck effect).

A 3D thermoelectric and heat conduction model is used to estimate the deflection of the electron beam used during welding of dissimilar metals. A weak coupling between analysed fields is assembled. Additionally, the influence of the deflection on the calculated fields was not taken into account. The problem is solved using a finite element method.

It is possible to model Seebeck effect in a relative simple way using the finite element approach.

The paper presents a detailed description of modelling procedure of a complex coupled field problem.

The purpose of this paper is to introduce and investigate a useful and practicable definition of the shielding effectiveness (SE) of enclosures for transient near‐field sources.

The transient SE is defined as the ratio of electromagnetic energies absorbed by an unshielded and by a shielded vanishingly small load. That ratio can be found analytically by means of a suitable spherical‐multipole approach. The SE can be reduced to easily measurable values of frequency‐domain electric and magnetic fields.

Suitable factors are introduced which depend on the frequency and on the distance between the dipole source and the measurement point inside the shield. The proposed definition has been analytically evaluated and validated for the case of a cylindrical shield.

The paper extends a recently proposed definition of the transient SE for plane‐wave incidence to the case of a dipole near‐field source.

This paper deals with magnetic field calculations and model‐based prediction of electromagnetic torque pulsations in a brushless DC (BLDC) motor.

The impact of a Halbach‐like magnetization and a multipolar excitation of permanent magnets are analysed. The measurement results from the prototype motors are well‐compared with those obtained from the model calculations. It is shown that the cogging torque in the motor with the multipolar excitation of permanent magnets is reduced six times as compared with the conventional BLDC motor.

The proposed method provides high accuracy of the analysis of coupled electromagnetic phenomena. The comparison between measured and calculated values of electromagnetic torque, cogging torque and EMF shows a very good agreement.

Reduction of the machine cogging torque is essential for practical applications of DC motors, in particular in the robotics industry.

This paper shows that multipolar excitation contributes to essential reduction of the cogging torque in a BLDC motor. This is confirmed by high‐quality numerical models of the motor, positively verified in experiments with motor prototypes.

The purpose of this paper is to reduce eddy current loss in a wire that is affected by an alternating field passing through it. This allows the efficiency of transformers to be upgraded and the quality factor in coils to be increased.

The use of a magnetoplated wire (MPW) is proposed to reduce eddy current loss in a wire. An MPW is a copper wire (COW) whose circumference is plated with a magnetic thin film. In additional, the theoretical equation for eddy current loss in an MPW is derived for ease of analysis.

The eddy current loss in an MPW is calculated as a function of the relative permeability and resistivity of its magnetic thin film to reduce the resistance due to the proximity effect of a coil. The eddy current loss in an MPW whose magnetic thin film has a relative permeability of 500 and a resistivity of 0.12 μΩm can be reduced to 4 percent that of COW at a frequency of 1 MHz.

The use of MPW can be expected to upgrade the efficiency of transformers and to increase the quality factor in coils.

The purpose of this paper is to present a hybrid numerical simulation approach for the calculation of potential and electric field distribution considering charge and dielectric constant.

Each numerical method has its own advantages and disadvantages. The idea is to overcome the disadvantages of the corresponding numerical method by coupling with other numerical methods. An augmented finite element method (FEM), linear FEM and boundary element method are used with an efficient coupling.

The simulation model of microstructured devices is not so simple. During the simulation various types of problems will occur. It is found that by using several numerical methods these problems can be overcome and the calculation can be performed efficiently.

The present approach can be applied in 2D cases. But, in 3D cases the calculation of augmented FEM in a spherical coordinate becomes quite elaborate.

The proposed hybrid numerical simulation approach can be applied for the simulation of the electrostatic force microscope (EFM) which is a very high‐resolution measuring tool in nanotechnology. This approach can be applied also to other micro‐electro‐mechanical systems.

Since the scanning process of the EFM is dynamic, it requires the updating of the FEM mesh in each calculation time step. In the present paper, the mesh updating is achieved by an arbitrary Lagrangian‐Eulerian (ALE) method. The proposed numerical approach can be applied for the simulation of the EFM including this remeshing algorithm ALE.

The purpose of this paper is to introduce a method for increasing imaging quality in impedance tomography. The paper presents an optical method of shape virtualization, processing algorithm draft and results of virtualization for sample objects.

In impedance tomography the image reconstruction algorithms must yield accurate images of impedance changes. One of the keys to producing an accurate reconstructed image is the inclusion of prior information regarding the physical geometry of the object. When the object under investigation is filled with transparent medium, optical methods can provide information about its interior and estimate the shape of non‐transparent interjections. Computer graphics methods (e.g. ray tracing) can be used to simulate propagation of the light transmitted along straight lines within the object, and thus yield geometric data to better imaging. The process of setting up boundary conditions is then supplied with additional information about interior of the object, which can significantly improve solution of the forward problem in impedance tomography.

The visibility matrix includes information about the interior of the object. However, the information is incomplete since the scanning is done along one axis. In order to obtain all remaining data, scanning along three axes is required. On the basis of the visibility matrix, the shape and volume of the non‐transparent interjections are recovered and then estimated.

The biggest novelty is indeed the combination of methods used in optical tomography with those in impedance tomography.

The purpose of this paper is to compare the accuracy of tracking the amplitude and frequency changes of non‐stationary electric signals.

Short‐time fourier transform (STFT) and S‐transform algorithms were applied to analyze non‐stationary signals originating from switching of capacitor banks in a power system.

The S‐transform showed possibilities of sharp localization of the basic component, and allowed improvement of tracking dynamism the transient components in comparison to STFT.

S‐transform is a better tool for the analysis of non‐stationary waveforms in power systems and its properties can be used for diagnostic and power quality applications.

The dynamic tracking of the changes in time and frequency of real‐like signals originating from a power system are investigated in this paper.