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A direct collocation technique is applied in modeling and simulation for scattering from a strip with PEC and partially PMC boundaries. By using the Green theorem the mixed boundary value problem is reduced to a system of hypersingular integral equations. Numerical results of scattering fields characteristics are presented.
The article deals with numerical modelling of a bottom electromagnetic stirrer with a rotating field. The influence of the magnitude of the current, working gap and frequency was considered. Three-dimensional numerical modelling of electromagnetic, hydrodynamic turbulent and temperatur fields using the commercial software package COMSOL Multiphysics.
The paper presents the results of the analysis of voltage and current distortions of the power system containing nonlinear load at changing location. The calculations are done for the power system consisted of overhead line 110kV, transformer station 110/15kV, overhead line 15kV and transformer station 15/0.4kV. Simulations were performed in the Microcap environment.
The program environment for electromechanical system analysis based on object-oriented approach and authorial method of mathematical modeling is presented. This environment allows constructing computer models of comprehensive electrotechnical systems with semiconductor converters. Such computer models are distinguished by the high operation speed and ability of real-time operation in interaction with...
This paper considers the physical experiments of a laboratory induction heating plant with various forms of billet. The obtained results of numerical simulation are verified with the help of a physical experiment. The main method of obtaining physical thermal and electromagnetic characteristics is the finite element method implemented in the computer environment of Comsol Multiphysics. The magnetic...
A novel concept of modular bistable electromagnetic actuator in valve operation is numerically analysed, designed and experimentally tested. The actuator takes advantage of permanent magnets for assuring stable positions of the valve body and field coils for control of the valve operation. The paper presents the basic concept of the actuator together with its numerical investigation for the case of...
Biological materials are characterized by high complexity and related unpredictability. Parameters of such objects could be described using stochastic approach. This paper presents methodology to create of probability density function for biological materials. Stochastic models are based on measurements of conductivity using specialized device. Problems related with temperature, moisture of the material...
Following paper presents new approach to the problem of automotive Ki-67 proliferation factor estimation in breast cancer biopsy images. This method is based on context filtering with designated neighborhood masks for edge detection. Proposed method was designed to compensate two major problems: cell shape divergence from ellipse and variability of color hue along with intensity in cell staining....
Two cases are considered: harmonic reduction and unbalanced load correction. The paper presents the method of reference signal detection for shunt active power filter control. The parallel filter used for the voltage shape improving in three-phase four wire systems is considered. The signal is detected from voltage harmonics. The method uses the state observer acting in frequency domain. The process...
This paper details exposure of wild type Saccharomyces cerevisiae yeast cells to low frequency electromagnetic field in the 0–2kHz region. We opted to use an excitation frequency of 800 Hz, firstly re-confirming our previously published results using a more precise evaluation method and extended our research by modifying the excitation signal shape — half sine waves, either positive or negative (with...
The methods of the theory of fractional-order calculus are used, which extends the possibilities of differentiation and integration to the operators of an arbitrary order during the synthesis of automatic control systems. The expediency of the use of Grunwald-Letnikov equation for the calculation of the fractional-order derivative and integral under the condition of limited signal sampling is demonstrated...
This paper proposes a sequential loading method, which finds the hourly changes of frequency and optimal load distribution between power stations. The method solves to minimize the aggregate cost in the electric power system (EPS). The method also calculates the surplus or deficit of an active power in EPS, hourly power flows of each transmission lines, active power losses in the networks. Computed...
This paper presents a fuzzy logic based speed control of an asynchronous motor by a 6-switched 3-level inverter. This inverter topology contains a new and alternative model to multi-level inverter topologies. The fuzzy logic controller and the space vector pulse width modulation techniques are used to generate the necessary signals for the inverter. The asynchronous motor is run without load and with...
The paper describes the method for indirect determination of the torque, power and energy indices of an induction motor shaft. A developed research laboratory stand is presented. It enables load testing of an induction motor with a possibility of direct measuring the torque, speed, currents and voltages of the researched motor. The analysis of the experimental research of the method for indirect determination...
The proposed paper deals with simulation and analysis of the radiofrequency field inside the multilayered human tissue model comprising a superficial metallic implant. The research was carried out using electromagnetic modeling based on the Finite Integration method and analysis was performed in terms of computing electric field distributions and spatial-averaged SAR distributions. The main objective...
In the paper the approaches how to develop models of electrotechnical objects using the test example of two-winding transformer are discussed. A comparing of the continuous model created using the description of physical processes and discrete macromodel obtained using the “black box” approach based on field experiment are carried out. It is shown that the model obtained using the “black box” approach...
The aim of this paper is to investigate the use of oculography signals for the recognition of experts in visual arts. We focused our attention on the number of sight transitions between characteristic image areas (ROIs). In the experiments we used oculographic data recorded at the Department of Experimental Psychology at the Catholic University of Lublin for 29 images and 34 users. The EM method was...
The article presents an innovative approach to the automatic detection of cells nuclei in FISH microscopic images. The proposed solution is based on L2 distance function which is used in patterns recognition in images. The results of researches show that an efficient identification of cells nuclei in FISH images with the presented method is possible. The numerical results show that the accuracy of...
When heat transfer phenomena is modelled in the domain of electrical engineering, exact values of boundary conditions and material parameters are generally unknown and for the simulation are in many cases estimated. In this article is presented calculation of heat flux which was previously unknown in the task of modelling heat transfer through multi layer firefighter smart protective suit. Heat flux...
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