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This study aims to model and investigate low-loss wave-propagation modes across random media. The objective is to achieve better channel properties for applying radio links through random vegetation (e.g. forest) using a beamforming approach. Thus, obtaining the link between the statistical parameters of the media and the channel properties.

A beamforming approach is used to obtain low-loss propagation across random media constructed of long cylinders, i.e. a simplified two dimensional (2D) model of agroforests. The statistical properties of the eigenmode radio wave propagation are studied following a Monte Carlo method. An error quantity is defined to represent the robustness of an eigenmode, and it is shown that it follows a known Lognormal statistical distribution, thereby providing a base for further statistical investigations.

In this study, it is shown that radio wave propagation eigenmodes exist based on a mathematical model. The algorithm presented can find such modes of propagation that are less affected by the statistical variation of the media than the regular beams used in radio wave communication techniques. It is illustrated that a sufficiently chosen eigenmode waveform is not significantly perturbed by the natural variation of the tree trunk diameters.

As a new approach to obtain low-loss propagation in random media at microwave frequencies, the presented mathematical model can calculate scattering-free wave-propagation eigenmodes. A robustness quantity is defined for a specific eigenmode, considering a 2D simplified statistical forest example. This new robustness quantity is useful for performing computationally low-cost optimization problems to find eigenmodes for more complex vegetation models.

The purpose of this study is to introduce a novel method for the measurement of electromagnetic material parameters.

The main idea behind the approach is the fact that for slabs with elongated shapes, the intensity of the backscattered field and the electromagnetic resonance frequency corresponding to the length of the sample are dependent on the conductivity of the sample’s material.

It is shown that for a known scattered field and resonance frequency, it is possible to formulate an inverse problem as to the calculation of the conductivity of the sample’s material at the considered frequencies. To investigate the applicability of the method, demonstrative experiments are performed during which the micro-Doppler effect is used to increase the measurement accuracy. The idea is extended to the case of anisotropic samples, with slight modifications proposed to the experimental setup in the case of significant anisotropy in the investigated material.

The measurement method may prove useful for the investigation of the high-frequency conductive properties of certain materials of interest.

To the best of the authors’ knowledge, this is the first time the use of the micro-Doppler effect is proposed for the purpose of the measurement of material parameters.

The electromagnetic modeling of inductively coupled, resonant wireless power transfer (WPT) is dealt with. This paper aims to present a numerically efficient simulation method.

Recently, integral equation formulations have been proposed, using piecewise constant basis functions for the series expansion of the current along the coil wire. In the present work, this scheme is improved by introducing global basis functions.

The use of global basis functions provides a stronger numerical stability and a better control over the convergence of the simulation; moreover, the associated computational cost is lower than for the previous schemes. These advantages are demonstrated in numerical examples, with special attention to the achievable efficiency of the power transfer.

The method can be efficiently used, e.g., in the optimal design of resonant WPT systems.

The presented computation scheme is original in the sense that global series expansion has not been previously applied to the numerical simulation of resonant WPT.

Fluxset type eddy current probes are used for detecting discontinuities in conducting materials. The measurements obtained by such probes can be used for the reconstruction of the parameters of the detected discontinuity if the output signal of the measurement is uniquely related to the measured field. In this paper a calibration method is presented for the establishment of the relation between the measured magnetic field and the output signal of the probe. The relation is obtained by the optimisation of the parameters of the mapping between the calculated magnetic field distribution and the measured output signal. The magnetic field distribution due to the interaction of the probe and an infinitesimally thin crack located in a conducting plate is calculated numerically by the solution of a boundary integral equation.

The purpose of this paper is to present a novel eddy-current modeling technique of volumetric defects embedded in conducting plates. This problem is of great interest in electromagnetic non-destructive evaluation and has already been exhaustively studied.

The defect is modeled by a volumetric current dipole density which satisfies an integral equation. The latter is solved by the classical method of moments. The authors propose the use of globally defined, continuous basis functions for the expansion of the current dipole density.

The proposed global expansion provides an improvement of the numerical stability and the performance of the simulation, over classical approaches. The proposed method is tested against both measured and synthetic data obtained by a different defect model.

The new discretisation scheme – in contrast to the classical approaches – does not need the discretisation of the defect volume. This involves numerous advantages that are discussed in the paper.

The purpose of this paper is to describe the development of simulation tools dedicated to eddy current non destructive testing (ECNDT) on planar structures implying planar defects. Two integral approaches using the Green dyadic formalism are considered.

The surface integral model (SIM) is dedicated to ideal cracks, whereas the volume integral method is adapted to general volumetric defects.

The authors observed that SIM provides satisfactory results, except in some critical transmitting/receiving (T/R) configurations. This led us to propose a hybrid method based on the combination of the two previous ones.

This method enables to simulate ECNDT on planar structures implying defects with a small opening using T/R probes.

The relation between the output of the fluxset sensor and the magnetic field is established by the numerical and experimental investigation of an ECT set‐up. A fast calculation method has been developed for obtaining the magnetic field generated by the interaction of the probe and the crack in a finite plate by superimposing the results obtained by the analysis of a finite plate without a crack and an infinite plate with a crack. The calculations are made by FEM and boundary integral methods, respectively. The relationship between the measured output and the magnetic field is obtained by calculating the calibration factors giving the best fit of the two sets of data. Based on the results, a numerical tool is developed for the quantitative evaluation of magnetic field sensors applied to the measurement of spatially inhomogeneous fields.

To propose a novel method for defect reconstruction in electromagnetic non‐destructive testing (NDT).

The inversion method is based on an optimized database that contains the measured signals for some predefined defect prototypes. The database is supported by an anisotropic simplex mesh, which has been generated adaptively in the abstract n‐dimensional space, spanned by the model parameters of the defect type. The actual reconstruction reduces to a mesh search and interpolation. The described theory is demonstrated in the paper by a solved NDT test problem.

We have realized that in addition to sole defect reconstruction, the database provides meta‐information about the quality of the inversion, the suitability of the chosen defect model parameters, as well as the capabilities of the testing experiment.

Defect models having several parameters require a sophisticated mesh generation algorithm, which works in higher dimensions.

In the authors' opinion the mesh database approach offers a totally new point of view of a given inverse problem, and may help in the better understanding of its nature.

The purpose of this paper is to accelerate the time‐consuming task of assembling the impedance matrix resulting from the discretization of integral equations by the moment method, accelerated using massively parallel processing scheme.

This paper provides several approaches for the implementation of moment method on compute unified device architecture (CUDA) capable general purpose video cards, as well as giving general implementation design patterns and a good overview on the topic.

The proposed method seems to be efficient in the light of the presented numerical results.

The subject of the paper is an evolving, considerably new aspect among computation techniques which could be of high interest for the scientific community.

The purpose of this paper is to provide a new methodology for the characterization of a defect by eddy‐current testing (ECT). The defect is embedded in a conductive non‐magnetic plate and the measured data are the impedance variation of an air‐cored probe coil scanning above the top of the plate.

The inverse problem of defect characterization is solved by an iterative global optimization process. The strategy of the iterations is the kriging‐based expected improvement (EI) global optimization algorithm. The forward problem is solved numerically, using a volume integral approach.

The proposed method seems to be efficient in the light of the presented numerical results. Further investigation and comparison to other methods are still needed.

This is believed to be the first time when the EI algorithm has been used to solve an inverse problem related to the ECT.