April 2019, Volume 19, Number 1
BOURI, S. — BENMANSOUR, A. Optimization of the Electrical Network by the Ant Colony Method 
MARGITOVÁ, A. — KANÁLIK, M. — KOLCUN, M. Impact of Ground Wires on the Series Impedance, Voltage and Current Conditions of Overhead Power Lines 
STAŠ, M. Alternative Proof on the Crossing Number of K1;1;3;n 
BRILLA, I. — JANÍČEK, F. Numerical Determination of Voltage Potential Inside Nonhomogeneous Media Using Variational Methods 
BENBOUHENNI, H. FPWM Technique Based Converter for IM Drives 
REPKO, M. — GAMEC, J. Comparison of the Impulse and MSequence UWB Radar Systems for the Estimation of the Wall Thickness 
DANKOVIČOVÁ, Z. — UCHNÁR, M. Extraction of Parameters from Dysgraphic Handwriting for CDSS Systems 
Summary: 
Sihem BOURI  Abdelhalim BENMANSOUR OPTIMIZATION OF THE ELECTRICAL NETWORK BY THE ANT COLONY METHOD [full paper]
A system is a set of processes and equipment to perform a task or a mission. The rational exploitation of the system depends on its
configuration. An optimal configuration avoids excessive expenses. The primary function of a modern electric power system is to
provide its customers with electrical energy as economically as possible with an acceptable degree of reliability. This degree of hope
requires an optimal design. In the engineering context, choosing equipment based on availability, cost, and performance is the most
important decision variable for optimizing a process. Depending on the availability of technologies on the market, the development of
an iterative algorithm will be necessary in order to adapt to each request its optimal structure. This article discusses the resolution of
a set of coherent problems that must be maximized, minimized, or minimized  to maximize singleobjective or multiobjective functions
under a set of constraints. These types of problems are called MaxMin / or Min─ Max functions.

A. MARGITOVÁ  M. KANÁLIK  M. KOLCUN IMPACT OF GROUND WIRES ON THE SERIES IMPEDANCE, VOLTAGE AND CURRENT CONDITIONS OF OVERHEAD POWER LINES [full paper]
Ground wires are bare conductors which serve to protect the power line from the lightning strike. This article deals with the
calculation of the series impedance of the 110 kV overhead power line with one ground wire. The article examines the effect of the
ground wire on the series impedance of the 110 kV power line compared to the same power line without the ground wire. In the next
part, the principle of elimination of the ground wire is described and the method of including the influence of the ground wire on the
series impedance of phase conductors of the 110 kV power line is also described. The conclusion deals with the calculation of voltage
and current conditions of the 110 kV power line modelled without the ground wire, with the ground wire and with elimination
(reduction) of the ground wire (the ground wire is not modelled, but its effect is included in the series impedance of phase conductors)
and then comparison of given models.

Michal STAŠ ALTERNATIVE PROOF ON THE CROSSING NUMBER OF K1;1;3;N [full paper]
The main aim of the paper is to give the crossing number of join product G+Dn for the connected graph G of order five isomorphic
with the complete tripartite graph K1;1;3, where Dn consists on n isolated vertices. The proof of the crossing number of K1;1;3;n was
published by very rather unclear discussion of cases by Ho in [5]. In our proofs, it will be extend the idea of the minimum numbers
of crossings between two different subgraphs from the set of subgraphs which do not cross the edges of the graph G onto the set
of subgraphs which cross the edges of the graph G exactly once. The methods used in the paper are new, and they are based on
combinatorial properties of cyclic permutations. Finally, by adding one edge to the graph G, we are able to obtain the crossing number
of the join product with the discrete graph Dn for one new graph.

Igor BRILLA  František JANÍČEK NUMERICAL DETERMINATION OF VOLTAGE POTENTIAL INSIDE NONHOMOGENEOUS MEDIA USING VARIATIONAL METHODS [full paper]
The problem of numerical determination of voltage potential inside one and two dimensional nonhomogeneous media using
values of the voltage potential on the boundary of the media has been solved. The convenient form of variational formulation of the
problem has been derived. The numerical solution of the problem has been obtained by the method of local variations.

Habib BENBOUHENNI FPWM TECHNIQUE BASED CONVERTER FOR IM DRIVES [full paper]
This article presents an improved pulse width modulation (PWM) based on fuzzy logic (FL) of induction motor (IM). The major
problem that is usually associated with PWM technique is the high total harmonic distortion (THD), stator flux ripple and
electromagnetic torque ripples. To overcome these problems a PWM strategy is proposed based on the fuzzy logic controller
(FPWM). The fuzzy proposed controller is shown to be able to reduce the THD of stator current, electromagnetic torque ripple and
stator flux ripple. The simulation results are shown by using MATLAB/SIMULINK software.

Miroslav REPKO  Ján GAMEC COMPARISON OF THE IMPULSE AND MSEQUENCE UWB RADAR SYSTEMS FOR THE ESTIMATION OF THE WALL THICKNESS [full paper]
In our laboratory, we developed a simple estimation of the wall thickness by the UWB (Ultra WideBand) radar system. The described
technique measures the wall thickness in the two steps. The first step is a measurement of the wall relative permittivity.
The second step is a reflections localisation and estimation of the wall thickness. The borders of the wall could be detected by the envelope
of the received signals. The described technique calculates the signal envelope by the Hilbert transform. Moreover, the relative
permittivity of the wall is estimated by the technique developed in our department as well. The effective relative permittivity is calculated
from the frequency dependency of relative permittivity. This technique was developed for the impulse radar system. The aim
of this article is compare the results from impulse radar system with Msequence radar system which operates in the time domain as
well measuring wall relative permittivity and wall thickness estimation.

Zuzana DANKOVIČOVÁ  Matúš UCHNÁR EXTRACTION OF PARAMETERS FROM DYSGRAPHIC HANDWRITING FOR CDSS SYSTEMS [full paper]
In this study we address the issue of the handwriting processing by extracting parameters from the written speech. The work applies
machine learning method – the decision trees method which aims to recognize the impaired handwriting, particularly dysgraphia. 55
features (e.g. total time, pen movement, pressure, speed, acceleration) were extracted from each out of 80 handwriting samples while
analyzing the performance of classifier for the dominant parameter – minimal speed, and without the dominant parameter as well.
The experimental results of the classifier are compared to the results of the statistical test – Mann Whitney Utest as a complex and
challenging endeavor to create an accurate classification.
