Communications - Scientific Letters of the University of Zilina, 2025 (vol. 27), issue 4
Operation and Economics in Transport
Carpooling in Transport in Today's ICT - Based Economy
Paulina Wiączek, Iryna Sitak, Alena Novak Sedlackova, Andrej Novak, Martin Bugaj
Communications - Scientific Letters of the University of Zilina 2025, 27(4):A48-A59 
The purpose of this research was, among other things, to show that the carpooling model can be regarded as a manifestation of collective intelligence and a response to the crisis of sustainability in today's ICT-based economy, which makes carpooling services a cheaper alternative to transportation services provided by other modes of transport: train and bus. The main research problem is contained in the question: How do collective intelligence and the tenets of sustainability influence the popularity of carpooling and the lower cost of carpooling services, compared to those provided by other forms of transportation? The critical literature analysis...
Mechanical Engineering in Transport
Methodology for Assessing the Key Operational Efficiency Indicators for Removal and Shunting Operations of Shunting Locomotives
Gabit Bakyt, Aizhan Makhanova, Murat Mussabekov, Galymzhan Ashirbayev1, Malik Zhamankulov, Kuantkhan Sarsenov, Aisha Mussabekova
Communications - Scientific Letters of the University of Zilina 2025, 27(4):B250-B260
The problem dealt with in this article is the methodology of the key performance indicators (KPI) evaluation of shunting locomotives operation when performing hauling and shunting work. The main parameters affecting the efficiency of rolling stock operation are described, including performance, fuel efficiency and locomotive utilization rate. The algorithm of KPI calculation is proposed, based on the analysis of operational data and statistical methods is proposed. According to the analysis of the trend in cargo transportation over the past 3 years, the need to develop a methodology for evaluating the key performance indicators of shunting work is...
Algorithm for Making the Optimal Decision for Further Operation of Freight Cars
Adil Kadyrov, Perizat Baigozhina, Aliya Kukesheva, Imanov Marat, Akbope Karsakova
Communications - Scientific Letters of the University of Zilina 2025, 27(4):B261-B277
The article deals with the methodology of selecting the optimal decision for the maintenance and operation of freight cars. The statistics of failures for the main units of freight cars has been collected. A hypothesis has been proposed about the method of selecting a decision based on the optimality criterion, i.e. the maximum profit. The optimality criterion is the difference between the income and the costs and is the function of the frequency of certain operations on each of the car units. An algorithm has been developed that allows for the effective optimization of the processes of operating, repairing, and writing-off the cars, ensuring an...
Electrical Engineering in Transport
Evaluation of Silicone Carbide Mosfet Driving Circuit Performance
Veronika Švárna, Michal Frivaldsky
Communications - Scientific Letters of the University of Zilina 2025, 27(4):C53-C60
The performances of different driving circuits configurations designed for silicon carbide MOSFET transistors are compared in this research. The simulation of the double-pulse test (DPT) was performed with the use of three driving circuit configurations. The SiC MOSFET NTH4L022N120M3S has great dynamic parameters, which made it suitable for the DPT simulation. It was performed with six different driving voltage ranges, all within the range between -10 V and 20 V. The results were taken across the wide range of driving resistances placed between the driver and the SiC MOSFET, where the switching losses were taken. Drawing from the observed measurements...
Detection of Selected Regulatory Traffic Signs Using Common Dashboard Camera
Dušan Koniar, Libor Hargaš, Matúš Danko
Communications - Scientific Letters of the University of Zilina 2025, 27(4):C61-C69
Nowadays, many modern vehicles contain a lot of systems for autonomous functions or driver assistance systems (traffic sign recognition). Modern vehicles contain many embedded systems and control units (also for signal and image processing), so implementation of deep learning or AI-based algorithms is possible. In older vehicles, mentioned systems missing or they are limited. In this paper is presented a design of algorithm for detection of selected regulatory traffic signs to extend the selected autonomous or intelligent functions of older vehicles. Algorithm is based on shape and color detection of key features of selected regulatory traffic signs...
Modelling of Dynamic States of Five-Phase Induction Motor
Pavel Záskalický, Daniela Perduková, Jan Kaňuch
Communications - Scientific Letters of the University of Zilina 2025, 27(4):C70-C77 | DOI: 10.26552/com.C.2025.053
In this paper is presented a mathematical model of a five-phase induction motor with a cage rotor and a stator coils connected to a star. In constructing the mathematical model, It is assumed that the motor is fed from a five-phase frequency converter with an ideal harmonic waveform of the output supply voltage. It is considered that the motor operates in an open control loop with the ability to control the frequency and amplitude of the supply voltage. The basic voltage equations in a two-phase coordinate system coupled to a stator are derived, as well as the relation for the electromagnetic moment. Based on the parameters measured on a real motor,...
Civil Engineering in Transport
Modelling the Equivalency Factor of E-Rickshaw under Heterogeneous Traffic Conditions
Amir Ali Khan, Sachin Dass
Communications - Scientific Letters of the University of Zilina 2025, 27(4):D102-D115
E-rickshaws, as emerging transport modes, notably affect mixed traffic flow on urban roadways. To evaluate their influence relative to other vehicle types, this study aim was to determine the Passenger Car Unit (PCU) value for e-rickshaws, as the Indian Roads Congress has yet to assign one. Three analytical methods were used: Chandra’s method, the homogeneous coefficient method, and multiple linear regression. Data were gathered via three-hour video recordings at three different locations, each in Hapur and Sonipat. Using VLC media player, vehicle speeds and counts were extracted for analysis. The data were then processed in SPSS and Excel to...
Management Science and Informatics in Transport
Geolocation of Devices in Low-Power Wide-Area LoRa Network
Ladislav Zemko, Daniel Hroš, Alexander Valach, Marek Galinski, Pavel Čičák
Communications - Scientific Letters of the University of Zilina 2025, 27(4):E46-E62
This article is focused on the geolocation possibilities in low-power deployments. A novel Logarithmic Distance Path Loss Model with a Memory (LDPL-M) algorithm is proposed to enhance the accuracy of determining the location of end devices. The proposed solution, utilizing the RSSI-based trilateration, proved more accurate by 24.54% compared to the conventional Logarithmic Distance Path Loss Model (LDPL). Compared to the Global Positioning System (GPS), the power consumption was 48.8% lower. These findings make it suitable for energy-harvesting deployments, environments with limited power supply, or generally hard-to-reach areas, covering various...