Communications - Scientific Letters of the University of Zilina, 2019 (vol. 21), issue 1
Operation and Economics in Transport
Proposal of the Functional System for the Airline Companies Financial Situation Assessment
Ondrej Stopka, Ladislav Bartuska, Jacek Caban, Larisa M. Kapustina
Communications - Scientific Letters of the University of Zilina 2019, 21(1):3-8 | DOI: 10.26552/com.C.2019.1.3-8 
This paper presents the draft methodology to be applied for evaluating the financial health of airlines. In the introductory part, specific attributes, regarding the individual types of airlines, are described. Subsequent parts of the manuscript outline advantages and disadvantages to measure airlines performance when implementing financial indicators, as well as a general procedure to evaluate the financial situation of a company operating in the aviation industry. The most important part of the paper includes the proposal of the specific functional system to evaluate the economic performance of airlines. Financial evaluation itself (evaluation of...
Do Air Passengers Decide Rationally? Case Study of Travellers on Route Prague-London
Katerina Pojkarova, Dalibor Gottwald
Communications - Scientific Letters of the University of Zilina 2019, 21(1):9-13 | DOI: 10.26552/com.C.2019.1.9-13
Decision-making is an integral part of every human's life, both personal and professional, and today's highly globalized world brings many different factors that affect the decision-making process. General economic theory of utility is grounded in the assumption that people make decisions rationally. Recently, however, its limits have been challenged by both scientific and professional public - the theory of rational choice acknowledges only a limited number of factors that influence the decision-making. The aim of the present article is to discover whether the current debate can be applicable to decision-making processes of flight passengers in a...
Mechanical Engineering in Transport
Passsenger Ride Comfort and International Roughness Index Specifications in the Slovak Republic
Peter Mucka, George Juraj Stein, Peter Tobolka
Communications - Scientific Letters of the University of Zilina 2019, 21(1):14-21 | DOI: 10.26552/com.C.2019.1.14-21
New original results are presented on relation between passenger's whole-body vibration (WBV) and longitudinal road unevenness characterised by the International Roughness Index (IRI) in 100-m segments. Measurements were provided in nine different cars of six vehicle categories operated on about 1860 km of road network. Vibration total value based on the root mean square (RMS) of the frequency-weighted acceleration was used to quantify the ride comfort at seat surface and seat base (i.e. vehicle floor) in three orthogonal axes. The relations between passenger's acceleration response, comfort reaction levels according to the ISO 2631-1: 1997 and the...
Influence of Components Bending on the Consecutive Plasma Nitridation and Barkhausen Noise Emission
Miroslav Neslusan, Jan Moravec
Communications - Scientific Letters of the University of Zilina 2019, 21(1):22-27 | DOI: 10.26552/com.C.2019.1.22-27
This paper deals with the non destructive evaluation of components after the plasma nitridation via the Barkhausen noise techniques. Effect of different surface states before the plasma nitriding is studied via the non destructive Barkhausen noise technique, as well as the conventional destructive techniques. Bending of flat samples to different bending angles was performed and magnetic, as well as conventional destructive testing, was carried out on the outer, inner and flat surfaces. The results of experiments show that the Barkhausen noise emission is a function of the heat treatment, whereas intensity of bending and the corresponding deformation...
Durability Determination of the Bearing Structure of an Open Freight Wagon Body Made of Round Pipes during its Transportation on the Railway Ferry
Oleksij Fomin, Juraj Gerlici, Alyona Lovska, Kateryna Kravchenko, Pavlo Prokopenko, Anna Fomina, Vladimir Hauser
Communications - Scientific Letters of the University of Zilina 2019, 21(1):28-34 | DOI: 10.26552/com.C.2019.1.28-34
In order to reduce the cost of designing and manufacturing of the new-generation open wagons, it is proposed to construct their carrying systems from round pipes. In order to exploit the proposed designs of wagons in international rail-water communication, it is assumed that they will be equipped with assemblies for fastening of chain binders. The maximal values of accelerations, as components of dynamic load acting on open wagons, made from round pipes during their transportation on a railway ferry, are determined. It is established that when moving the body in the vertical direction for a wagon located on the upper deck, the maximum acceleration...
Electrical Engineering in Transport
DC-DC Converter Design Issues for High-Efficient DC Microgrid
Michal Frivaldsky, Jan Morgos
Communications - Scientific Letters of the University of Zilina 2019, 21(1):35-41 | DOI: 10.26552/com.C.2019.1.35-41
In this article, the electrical properties, as well as the economic aspects of the modular and non-modular solution of the DC-DC photovoltaic converter for DC microgrid subsystem, are described. Principally a theoretical overview of the circuit configuration for the selected DC-DC stage of the DC microgrid system is shown. It is dealt with the comparison of the one non-modular high - voltage SiC-based dual - interleaved converter operating at the low switching frequency and with modular low voltage GaN-based DC-DC converters operating at high switching frequencies. The main focus is given to the research of the dependency that arises from the different...
Civil Engineering in Transport
Turnout Monitoring with Vehicle Based Inertial Measurements of Operational Trains: A Machine Learning Approach
Mykola Sysyn, Dimitri Gruen, Ulf Gerber, Olga Nabochenko, Vitalii Kovalchuk
Communications - Scientific Letters of the University of Zilina 2019, 21(1):42-48 | DOI: 10.26552/com.C.2019.1.42-48
A machine learning approach for the recent detection of crossing faults is presented in the paper. The basis for the research are the data of the axle box inertial measurements on operational trains with the system ESAH-F. Within the machine learning approach the signal processing methods, as well as data reduction classification methods, are used. The wavelet analysis is applied to detect the spectral features at measured signals. The simple filter approach and sequential feature selection is used to find the most significant features and train the classification model. The validation and error estimates are presented and its relation to the number...
Concentrations of Traffic Related Pollutants in the Vicinity of Different Types of Urban Crossroads
Dusan Jandacka, Daniela Durcanska, Dasa Kovalova
Communications - Scientific Letters of the University of Zilina 2019, 21(1):49-58 | DOI: 10.26552/com.C.2019.1.49-58
Pollution of the air by gases and particulate matter is a problem of everyday life. Particulate matter (PM) is one of the hazardous pollutants causing deterioration of the environment and thus quality of life of the population. Long-term exposure to effects of increased concentrations of gaseous pollutants can also cause deterioration of the environment and human health. Particulate matter and gases production by the road transport is a burning issue, particularly for larger urban areas. Many factors influence the air quality what determines its development and changes. Air pollution monitoring was focused on a possible change in the concentrations...
Acceleration Response of the Railway Bridges - Verification of the Limit State of Acceleration
Milan Moravcik
Communications - Scientific Letters of the University of Zilina 2019, 21(1):59-67 | DOI: 10.26552/com.C.2019.1.59-67
The dynamic response of a girder bridge under trains is studied with an emphasis on the vertical track acceleration. The vehicles are modelled as a series of moving loads. The efficiency of the method is demonstrated on the simply supported railway bridge of the length Lb = 38m subjected to the series of the bogie forces of the conventional IC train. The closed-form solution of the bridge response with the intention to resonance and cancellation effects is applied. The acceleration response is investigated for the resonance train speed c = 65 m/s = 234 km/h, considering the modes of vibration j = 1 and j = 1+3, because higher modes can have significant...
Safety and Security Engineering in Transport
Assessment of the Mobile Risk Source in Road Transport
Katarina Makka, Darina Stachova, Katarina Kampova
Communications - Scientific Letters of the University of Zilina 2019, 21(1):68-73 | DOI: 10.26552/com.C.2019.1.68-73
Assessment of the mobile risk sources is not yet established in the European Union by law and therefore there is not enough pressure to manage and reduce risks. However, the transport of dangerous goods poses a special risk in terms of the nature of the transported material, especially for densely populated urban areas. The release of toxic or flammable substances into the air may endanger the health and life of many inhabitants. The assessment of consequences of the mobile accident hazards has been dealt with only seldom and not in details. The aim of this paper is to assess the risks associated with the transport of dangerous flammable substance....
Erratum
Errata: Communications - Scientific Letters of the University of Zilina, Vol. 20, No. 3, 2018, "Electrochemical Characterization of Az31 Magnesium Alloy Treated by Ultrasonic Impact Peening (Uip)", pp. 24-29. The proper Acknowledgement should be as follow
Daniel Kajanek, Branislav Hadzima, Filip Pastorek
Communications - Scientific Letters of the University of Zilina 2019, 21(1):75-79 | DOI: 10.26552/com.C.2019.1.75-79
Errata: Communications - Scientific Letters of the University of Zilina, Vol. 20, No. 3, 2018, "Electrochemical Characterization of Az31 Magnesium Alloy Treated by Ultrasonic Impact Peening (Uip)", pp. 24-29. The proper Acknowledgement should be as follows:The research was supported by project ITMS 26220220048 and by Slovak Research and Development Agency by the project No. APVV-14-0772.