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The article deals with the power analysis of semiconductor devices nowadays commonly used in perspective traction inverter topologies suitable for automotive industry applications.  The power analysis is devoted to topologies, which are the Voltage Source Inverter (VSI) topology and perspective three-level alternatives, which are the Neutral Point Clamped (NPC) and T-type Neutral Point Clamped (T-NPC) traction inverter topologies. The main part of the power analysis of the proposed topologies is done on multi-phase versions (specifically six-phase). Mentioned topologies are modelled through the use of the simulation environment PLECS, while the focus is given on the accurate determination of semiconductor devices' power losses. Collected data of each analyzed topology are then processed using the MATLAB environment. The analysis of power parameters aims to find out which of the mentioned topologies achieves the highest efficiency as an VSI system at various power levels using the same input parameters.

The impact of polyphosphoric acid (PPA) polymers and crumb rubber (CR) on bitumen's properties to enhance its performance was examined in this study. Laboratory samples were created with varying percentages of PPA (0.5 % to 2 %) and CR (6 % to 18 %) and subjected to extensive testing. Findings indicated that the combination of PPA and CR led to notable improvements in bitumen performance, including increased viscosity, softening point, elasticity, and recovery rates at elevated temperatures. Specifically, samples with 18 % CR and 1.0 % or 2.0 % PPA demonstrated exceptional rheological properties and strength. The optimal combination (18% CR and 1.0% PPA) resulted in a uniform structure, while the maximum CR content did not compromise bitumen integrity. Both additives effectively minimized temperature sensitivity and aging, enhancing the bitumen's performance class significantly.

This article presents the enhancement and refinement of a simulation model for an integrated universal switched voltage regulator compatible with PSPICE software. The model enables users to create representations of any specific type of switched voltage regulator currently available on the market. The described regulator model is practically applied in widely used configurations of buck converters, including applications in transportation. The accuracy of the regulator model is verified by comparing the simulated waveforms of the converter to those provided in its datasheet. Additionally, the model is employed for the design and simulation analysis of buck converter circuits, with extended current and voltage ranges for their output parameters. In the context of improving the performance of such converters, particular attention is given to enhancing their electromagnetic compatibility.

The lifespan prediction of the bus body of the load-bearing structure has been made and compared to the results of real operation. The maximum approximation of the simulation modelling results in Matlab Simulink to real operation is explained by taking into account a sufficient number of factors influencing durability. This research has the particularity that it allows determining the durability of the bus body even at the design stage, which was not possible with accelerated tests or during the operation of the bus on real routes. The obtained results can be used by bus manufacturers at the design stage, allowing them to change the construction and technology of anticorrosion protection, thereby influencing the durability. In addition, operating organizations will be interested in the obtained results when using the developed methodology in various operating conditions.

This work describes the features and methods of measuring the forces of interaction between the wheel pairs and rails by measuring wheel deformations at control points. The work also contains recommendations for direct measurements of the forces of interaction between the wheels and rails to determine the actual margin of stability of wheel pairs from derailment. The result of the work is general requirements for the system of direct measurement of the strength of interaction of the high-speed rolling stock wheel pairs with rails and scientifically based recommendations for direct measurement of the interaction forces of wheels and rails. The problems of interaction between the wheel pairs and rails do not significantly depend on the track width and are general in nature for different countries of the world.

During the movement of the train in various operational regimes, a series of deficiencies arise in the mechanical components, which depend on kinematic and parametric factors affecting the working conditions of the traction drive. An innovative traction drive is discussed in this article, which prevents the non-uniform distribution of parametric factors, as well as dissipative, inertial, and elastic characteristics along the length of the track.

Traffic safety assessment is an essential part of traffic planning and engineering. At uncontrolled intersections, the severity of crashes has increased manifolds. This is due to the fact of not following the priority rule during the right-turning movements. In conventional methods, past accident records were used to analyze traffic safety. However, the drawbacks of the traditional method to estimate the severity require a lot of accident data for analysis to draw any conclusion and suggest safety measures. The accuracy of the record of accidents and details is highly uncertain. Therefore, surrogate safety measures are being used to analyze the safety. In the present paper, the gap acceptance time (GT) is used to examine the risk and the speed and gap values define the level of risk and severity (LORS). Moreover, using the value of the critical gap, the probability of risk is estimated. Further, the level of risk and severity is computed based on the gap and speed data of vehicles at an uncontrolled intersection. Hence, with the speed and gap data, the level of risk and severity is classified as low risk, high risk and low severe, and high severe. The methodology implemented is validated by using the actual accident data.

This paper provides an analysis of the values of safety distance between the two moving vehicles, based on the parameters of the behaviour of young drivers. The main objective of this research was to determine the driver's response time for braking manoeuvre (BRT) in car-following situations. The test results were used to verify certain recommendations for the vehicle driving parameters, the principles of driver's performance to increase road traffic safety, etc. The driver's response times, determined during the testing in the simulator, were used to assess the recommended values of the safe following distance under different road conditions and various ways of driver behaviour. In the paper, for different values of BRT a safety distance in emergency traffic situations was determined.

Hydraulic motion platforms are widely utilized in various environments due to their capacity to bear heavy loads and provide long actuator strokes. The predominant control system employed for hydraulic motion platforms is the electro-hydraulic servo system (EHSS) due to its high accuracy and robustness. However, compared to other types of hydraulic valves, the electro-hydraulic servo valve (EHSV) is less durable. An alternative system to EHSS is the electro-hydraulic proportional system (EHPS), which employs an electro-hydraulic proportional valve (EHPV) instead of the EHSV. The EHPV resolves the durability issue at the expense of accuracy and system error. The optimization of durability and accuracy is the core of this study. The tracking behavior and response of both Three degrees of freedom (3 DOF) motion platforms using EHSS and EHPS are investigated across different frequency ranges.

At the underground mines of Kazakhmys Corporation, where different types of highly productive self-propelled equipment with different types of pneumatic wheel drive are operated, there are significant downtime of technological equipment. As practice has shown, application of repair system with use of old methods and means, at operation of underground self-propelled equipment appeared to be ineffective. One of the main reasons of low efficiency of self-propelled machines operation is the absence of the system of continuous monitoring of technical condition of each machine and its aggregates with application of methods and means of diagnostics. To avoid failure, it is necessary to establish the predicted and residual resource at a certain operating time of the machine according to the diagnostics data. This paper outlines the results of research on predicting the residual life of machine units used in the conditions of the mine corporation "Kazakhmys".

The analysis of the statistical values of wear of brake pads in operation, based on which a wear model was developed, is presented in this paper. This model can be used for predicting the remaining service life of brake pads according to the wagon mileage.
The distribution function of wear on the upper and lower parts of the pad was determined, which made it possible to find the main qualitative characteristics, namely, the wear intensity, the γ-percentage wear, and the average pad wear at a specified wagon mileage.
The results of the study can be factored for solving complex engineering problems of excessive wear of composite brake pads used for freight rolling stock; they could also help to extend the guaranteed overhaul period and improve the railway traffic safety.

The article is devoted to the study of dynamic interaction of rail track and freight wagons under increased axial load. In conditions of increasing the freight traffic volumes and axial loads, the importance of accurate understanding of the mechanisms affecting the wear of rail track elements becomes especially important. In this paper the authors have carried out experimental research and comparative analysis of freight wagon trolleys of different models. As a result of dynamic tests of the freight wagon trolleys, the necessary parameters of dynamic qualities of different models of wagons and their optimal values of axial loads of freight wagons are obtained. The necessity of improving the current design of wagon trolleys and reinforcing the design of railway track with the use of R65 type rails and reinforced concrete sleepers is substantiated. According to the data of trolley design comparison of different models, the bending moment and maximum load indices are established.

Every year a large number of vehicles travel on Poland's roads. The technical condition of vehicles largely depends on the technical condition of the road infrastructure. For this reason, the purpose of the article was to analyze the technical condition of the road infrastructure. The analysis was carried out with the help of a questionnaire survey on a random group of 380 people living and using roads in the Wielkopolska province.

The quadcopter persist as important roles across diverse applications, and the enhancement of their control efficacy has been the subject of extensive research.
In this work, the authors proposed optimal Proportional Integral (PI) controller based Fuzzy Logic Control (FLC) for the roll, pitch, altitude, and yaw motions of the quadcopter system. The proposed technique uses the Particle Swarm Optimization (PSO) algorithm to tune the parameters of the FLC and enhance the quadcopter performance. The simulation results show that the proposed technique achieves smoothness of control and significant improvement over classical techniques, as the rise time and the settling time are reduced by 61 % and 66 %, respectively. These times are important for stabilizing the system’s response speed and avoiding overshooting or oscillating. This indicates that the FLCPI-PSO can achieve the desired roll and altitude angles more rapidly and effectively.

The article highlights is determination of the main strength indicators of the modernized brake lever transmission for a wagon bogie. The special feature of this modernization is that the technological pin-hole in the strut is displaced by 112 ± 2 mm towards the bolster beam, i.e., in line with the pendulum joints. This helps to eliminate abnormal wear of the brake pads in operation. To substantiate the proposed modernization, the strength of the brake lever transmission was calculated. It was found that the maximum equivalent stresses were 124 MPa; they occurred in the tension member. The resulting stresses did not exceed the permissible values. Thus, the proposed modernization measures are appropriate.
This research could improve the safety of rail freight operations and profitability of the rail transport.

The study is focused on the relationship between firm growth and firm size. The aim of this study is to examine the growth-size relationship and test Gibrat's law validity in the Czech transportation and storage industry. To examine the relationship between firm size and firm growth, the linear auto-regression model is applied. The sales and sum of total assets are used as indicators of the firm size. The final sample contains data for more than 6,000 Czech firms in the period 2008-2017. The results have shown that Gibrat's law is not valid in the Czech transportation and storage industry. Smaller firms tend to grow faster than larger ones. Due to the limited scope of data, we were only able to verify the validity of Gibrat's law. The data used do not allow to examine the factors influencing the faster growth of small companies compared to large companies. It will be the subject of further research.

The article discusses the types of urban electric transport used in Belarusian cities, gives a detailed classification and comparison of available vehicles. Various options for increasing the share of environmentally friendly transport through the use of electric buses and trolleybuses are considered, an assessment and a comparative analysis of the options are given. Features of the drivers' work planning and drawing up of the schedule taking into account safety requirements are considered.
A methodology for assessing the efficiency of urban passenger transport has been developed, taking into account the development of electric vehicles.

The work highlights the results of a study into the dual wedge-shaped wear of composite brake pads for freight wagons. It has been found that the over-normative wear makes the area of a composite brake pad larger in the lower part up to a value directly proportional to the wagon mileage and smaller in the upper part. To assess the braking efficiency of a rail vehicle, a graphical analytical method has been developed; it allows determining the factor of dual wedge-shaped wear of pads depending on the wagon mileage. The results of calculation were verified by comparing two samplings obtained by mathematical and computer modelling. The results of calculation have proven that the hypothesis on the adequacy is not rejected.
The results of the study conducted will allow more accurate assessment of the braking efficiency of freight rolling stock to be made, as well as contribute to improving the safety of train traffic.

In the paper, some selected results concerning the ellipses of adhesion for various conditions of motion of a vehicle model, have been presented. The analysis, regarding the phenomena between the road and the wheels of the given motor vehicle's model, was previously carried out in the earlier paper by the author. However, they proved useful for the second part of research based on determination of the ellipses of adhesion. This can enable answering the question whether the road conditions may affect the maximum longitudinal and lateral forces combining such ellipses in the contact plane between the road and the wheels. The analysis has been presented based on the previously obtained results.

The automotive industry, known for its dynamism and innovation, relies on effectiveness of product and process requirements management. Effective collaboration with OEM (Original Equipment Manufacturers) is essential for success. The article analyses how product and process requirements evolve during different project phases, following the APQP (Advanced Product Quality Planning) approach, depending on OEM type. The study focuses on Tier 1 organizations, direct suppliers to the automotive industry, and their diverse approaches to product development. It underscores the need for Tier 1 organizations to maintain flexibility in their operations and to be prepared for changes in OEM demands. The study emphasizes the role of effective communication and coordination among all the levels of the supply chain to ensure the successful implementation of the APQP approach.

The influence of the cutting angle on the resistance to the bulldozer blade burial during its movement, taking into account the one-sided stressed state of the soil, was studied in the research results of which are presented in this paper. It is established that the resistance to deepening is significantly reduced when the machine is moving, which allows using smaller cutting angles without increasing the energy consumption. Constructive features and kinematics of the working equipment are considered, including a promising parallelogram scheme, which provides automatic reduction of the cutting angle during deepening. Calculations of the resistance of the blade penetration into the ground, and experimental data confirming the cutting force reduction up to 7%, for each degree of angle reduction, are given. It is determined that the optimum cutting angle is 30-40°. The obtained results can be used to increase the productivity of bulldozers and optimize the design of their working equipment.

The paper presents possible models of electric buses purchase financing, taking into account purchase prices higher now than in the case of traditional buses. During the research, the solutions used on several continents and in many countries were analysed, including the USA, China and many European countries. The qualitative research methods were used, focusing less on the describing and dimensioning the current state and more on creating and presenting theories and the implementation proposals themselves. As a result, it also allowed to include issues related to applicability and implications of formulated solutions for managerial practice.

Accident prediction models are mathematical expressions or algorithms used to determine the causal factors for road accidents and road safety engineers are using these models, as well. Modelling this kind of accident is quite challenging and required good quality of data. The results of the artificial neural network model, Gaussian processes model, and support vector machine model are compared for vulnerable road accident frequency in this study. The accident frequency dataset comprises 218 records, with 146 designated for training purposes and 72 reserved for testing. The model's accuracy was contingent on: the mean absolute error, root mean square error and coefficient of correlation. The findings suggest that for predicting the vulnerable road user accidents on roads, the artificial neural network gives better correlation results as (0.912) that the support vector machine (0.879) and Gaussian processes (0.853).

Since the electrical vehicles (EVs) are infrastructure-dependent technology, their penetration faces the problem of lacking recharging infrastructure. Thus, there is a dilemma of chicken-egg in the penetration of EVs and their charging infrastructure for the decision-makers. The article examines the e-mobility scenario of 3 Indian cities to understand issues and challenges in implementing EVs. The study suggests a co-diffusion strategy for the EVs and charging infrastructure. Firstly, the priority EV segment has been decided based on the transport mode preference. Then, suitability of charging facilities according to the segment of the EVs has been presented by analyzing the turnover rate and time spent at several places. The study recommends policies on the upfront cost of EVs, charging infrastructure, awareness generation and others, while leveraging the existing government schemes like Atmanirbhar Bharat and FAME-II.

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 justified. A comparative analysis of various approaches to assessing the operational performance of locomotives is carried out, their advantages and disadvantages are revealed. Practical recommendations for improving the operational performance of rolling stock are described.

A surprising number of people die on Polish highways every year. Despite the fact that number is decreasing year after year, it is still rather considerable. Due to the epidemic, the costs of the road accidents were significantly lowered, but they still remain fairly large. Understanding the roads where the majority of accidents happen and the anticipated number of accidents in the next years are necessary to lower this number. The purpose of the article was to forecast the number of accidents that would happen on Polish roads based on the kind of roads. To do this, annual accident statistics from the Police's statistics for the years 2001-2021 were reviewed, and a forecast for the years 2022-2031 was produced. It is clear that either the accident rate is increasing or it is steady. Predictions also suggest that a large increase in accidents on Polish roads may be expected given the current situation.

In this study, the effect of five geometric design features, including radius, superelevation, longitudinal grade, lane and shoulder width, on the average speed in the horizontal curve on a two-lane undivided rural road was investigated. The standardized regression coefficients showed that the most important factor affecting the speed was the radius (10.47) followed by the longitudinal grade (4.46). Superelevation and lane width had little effect. Shoulder width had no significant effect. This would be due to the wide width of the lanes. It was found that the relationships between speed and radius, longitudinal grade, superelevation and lane width were radical, quadratic, linear and linear, respectively. Increasing the longitudinal grade has increased the speed of the drivers. Increasing the superelevation was effective when its value changed from negative to positive.

The behaviour of lightweight concrete (LWC) edge column-slab connections reinforced with two types of flexural reinforcement glass fiber-reinforced polymer (GFRP) and steel bars with different ratios of shear reinforcement are investigated experimentally and analytically using ABAQUS software. The experimental protocol covered evaluation of eight slabs and edge columns measuring subjected to static loading. Slabs are evaluated as supported, free-standing at one edge, and the column connection is included. The slabs are divided into two groupings, with four slabs in each group. The first group was reinforced with steel flexural, while the second group was reinforced with GFRP reinforcement. Within each group, one slab lacked shear reinforcement, while the other was reinforced with a varying shear reinforcement ratio. A good agreement was found between the numerical FE model and experimental outcomes in most tested slabs.

The results of research, devoted to operation of an electric pulse muffler designed for cleaning exhaust gases of an internal combustion engine, are presented in this article. The problem considered in this research is establishing the optimal operating mode of the electric pulse muffler by changing the parameters of the distance between the electrodes and the frequency of the electric pulse. To solve this problem, experimental research on laboratory and experimental stands was carried out, which confirmed effective reduction of the gas smoke indices at adjustment of the specified parameters. As a result, a methodology was developed to calculate the optimal values of the distance and frequency parameters, at which the operation of the electric pulse muffler will be considered productive and the degree of gas purification will be effective. The optimum value of the distance between electrodes is 0.78-6 ∙10-3 m with an electric pulse frequency in the range of 127-128∙10³Hz.

Cylinder liners of an automotive internal combustion engine are subject to significant losses during operation. Severe operating conditions of cylinder liners lead to the appearance of various defects that must be eliminated to ensure the performance of the internal combustion engine. Currently, several methods have been developed for restoring and strengthening the inner surface of cylinder liners of automobile and tractor engines. Analyzing the considered methods for strengthening and restoring cylinder liners, their advantages and disadvantages from the point of view of increasing their durability, it can be assumed that the high-quality restoration of cylinder liners will be provided by a method of applying a coating by centrifugal induction sintering of powder material. Self-fluxing powders were used as baked powder material.