Fulltext search in archive

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. Authors would like to point out that the mobile resources represent a significant source of risk through the transport of dangerous goods in the event of an emergency occurrence associated with their leakage.

The paper presents a methodology for the design of the production process of a new product from the point of view of manufacturability criterion assembly operations (Design for Assembly - DFA) in the automotive industry. Methods and techniques, used in implementation of the DFA method to produce a new product, are mentioned. Impact of those methods on improving the assembly technology of a complex product is described. Suggestions for improving the abovementioned methods are presented, as ell. The examples given illustrate the proposed procedures.

Capacity assessment of urban roads according to Slovak standard does not sufficiently take into account the influence of vehicle maneuvers on road section performance between the two intersections. This research analyzed turning relations on selected urban road intersections and the influence of right turn and left turn on major stream speed changes. For the purpose of determining the influence of the right turn on decrease in capacity, measurements were carried out at 7 uncontrolled intersections with curve radius ranging from 6 to 30m. To determine the influence of the left turn on the capacity of urban road a critical gap was evaluated, using the Raff's, method, based on the analysis of accepted and rejected gaps in the major traffic stream, which was one of the main inputs for simulations. The findings were used to determine the influence of selected maneuvers on the road capacity, which led to a proposal for reduction coefficients based on computational analysis performed using simulations in PTV VISSIM.

The paper deals with the direct AC-AC propulsion system and compares two matrix converter concepts with fivephase traction induction motors (IM) for the hybrid electric vehicle (HEV) including electronic differential. The first one consists of [3x5] matrix converter and [3x1] active PWM rectifier (4Q-converter) for full power performance. The second one comprises one [3x5] matrix converter for full power and auxiliary [0x5] matrix converter for partial output power. Configurations of [3x5] + [0x5] MxC converters with five-phase motor(s) are not analyzed in available literature so far. The advantage of the proposed connection is in supposed higher efficiency of matrix converter then clasiccal VSI one. Part I deals with a theoretical study of converter concepts for hybrid electric vehicle. Based on simulation results the comparison and evaluation of the property and quality of the quantities of different type of the matrix powertrain are discussed in Part II.

Aerodynamic modelling currently relates to development of mathematical models to describe the aerodynamic forces and moments acting on the aircraft. It is a challenging part of aerodynamics that defines a comprehensive approach to using traditional methods and modern techniques to obtain relevant data. The most complicated task for the aerodynamics and flight dynamics is definition, computation and quantification of the aerodynamic description of an object. This paper presents how to determine the aerodynamic load on a gyrocopter and defines the effect on its stability and control. The first step to solution is to develop simpler approximate aerodynamic model - a model that can be used in analysis of aerodynamic load and can represent the aerodynamic properties of the gyrocopter with an acceptable degree of accuracy. Control and stability are very important parts of aircraft characteristics and therefore those characteristics were analyzed in simulation. Finally, the aerodynamic data outputs are assessed in terms of impact of aerodynamic loads on stability and control of the gyrocopter model.

A crucial aspect concerning the intelligent transport systems is data transmission between vehicle and central control and information systems. Transportation needs a reliable system of data transfer based on GSM or WiFi networks. However, these networks employ a wide range of different frequencies which can be harmful to the health of drivers. The detrimental effect of electromagnetic radiation can negatively affect the process of transportation. This study determines the intensity of electric field levels (E) of the radiofrequency electromagnetic field (RF EMF) during the data transmission through the 3G, 4G and local WiFi networks, comparing them with the limit values. Conclusions: Our results showed a significantly higher level of the E-field intensity during 4G transmission in all places. The limit values were not exceeded. The lowest E-field values were found in local WiFi network.

The insurance sector is in many ways unique, because insurance companies must use specific marketing tools to satisfy their customers and insurance companies have with customer's long-term relationships. Insurance companies must continuously monitor the insurance market, especially type of demand for insurance products and customer requirements. The number of registered vehicles in the Czech Republic is annually increasing, which causes an increase of total premiums written of the motor third party liability insurance and insurance companies must monitor this insurance product and analyse demand for it. The aim of this article is to analyse the seasonality of total premiums written of motor third party liability insurance in the Czech Republic in years 2000 - 2016.

The aim of the article is to compare the motivation level of senior managers and blue-collar workers in Slovak small and medium-sized enterprises providing transport for forestry sector with the focus on the creation of motivation programs. The analysis included 340 senior managers and 262 blue-collar workers. A total of 30 motivation factors were examined. The most important motivation factors were defined. We identified the significant differences between the needs of senior managers and blue-collar workers by using the Student two-sample t-test. Based on the results of our testing we may conclude that in the field of motivation factors in Slovakia it is not possible to establish a uniform motivation program for the analyzed groups of employees. In the future, after meeting the needs of employees, it is possible that motivation may change with the change of requirements.

The paper deals with the communication between the infotainment elements and the drive component of the car using the CAN bus. In the introduction, there is briefly described the communication bus used in cars. It describes its basic features, benefits and utilization. The main task is graphically programmed and builds a dashboard that will resemble to a real dashboard from a Volkswagen Golf 5. Using the dashboard built in LabVIEW, it controls the real dashboard.

The purpose of this study is to find ways to increase the effectiveness of cross-cultural communications from the standpoint of Ukrainian business. The methodology of the research is based on statistical measures; there is quantitative identification of parameters of intercultural business communication processes, their modeling, analysis and forecasting. As a result of the study, the relationship between different types of intercultural communication is determined: the transaction oriented and the relationship, formal and informal, monochrome and polychrome, expressive and restrained. Profiles and classifications of the cross-cultural communications have been constructed. The communication disagreements and corresponding reactions of Ukrainian businessmen in different countries and regions of the world have been determined. Models have been developed that reflect the patterns of the relationship between the success of communication (reaction) and intercultural differences. The obtained results can be used to substantiate the cross-cultural communication strategies of business trips.

Airspace domain may be represented by a time-space consisting of a three-dimensional Cartesian coordinate system and time as the fourth dimension. A coordinate system provides a scheme for locating points given its coordinates and vice versa. The choice of coordinate system is important, as it transforms data to geometric representation. Visualization of the three and more dimensional data on the two-dimensional drawing - computer monitor is usually done by projection, which often can restrict the amount of information presented at a time. Using the parallel coordinate system is one of possibilities to present multidimensional data. The aim of this article is to describe basics of parallel coordinate system and to investigate lines and their characteristics in time-space.

Fierce rivalry in the transport market raises serious reassessment and implementation of new approaches to logistics companies and trade enterprises in marketing of goods. To maintain the volume of domestic sales and output to the external one, producers and trading firms are forced to expand their trade and economic relations that occur in other regions. The integration of the world economy and policy orientation of foreign trade to free trade greatly simplify the task of setting up the free trade and economic connections, but the question is how quickly and efficiently, with the least costs, it is necessary to put the goods in the right region to the customer.In modern market conditions, international container transportation of goods between Ukraine and the European Union countries has a prospect of development, as each year the number of orders in transport and logistics enterprises increases. After analyzing the status of orders, the problem has been detected and widely connected with the method of organization of container cargo delivery in international communication and the formation of rational technology of serviced. To solve this problem a method of logistic approach to the system of containers transportation has been proposed based on the cybernetic model "white box". The initial stage of its implementation involves formation of the limitation system of input parameters and factors that are consistent with the needs of the customer firm and the company performing transportation. Ten alternative order services schemes, each of which takes into account the possible combinations of operations, has been proposed.Based on the company "Inter Trans Logistic", which serviced the order of the company "Agricultural Holding August" for the transportation of rape seeds, 10 tons of corn on demand and a portion of sunflower oil 20,000 liters, according to their applications for transportation, a logistic approach using a cybernetic model "white box" has been implemented. Based on the mathematical models of changes in the total costs of the international container cargo shipping company of the customer, it has been shown that the maximum expenses are occurring in the implementation of the scheme 1 service order. In that case, the costs have been in the range of 848.72 to 7455.41 US $, according to a certain series of experiments. Based on the condition of the minimum cost function for container transportation, scheme 1 has been chosen as limiting scheme of service order against which the assessment carried out changes of the total costs in the implementation of other schemes. In percentage display according to Scheme 1, the following percentage intervals have been deducted for the reduction of sales costs: Scheme 2 - 12.70 to 34.98%; Scheme 3 - 2.93 to 12.00%; Scheme 4 - 2.06 to 10.88%; Scheme 5 - 1.69 to 4.25%; Scheme 6 - 0.87 to 3.28%; scheme7 - 0.97 to 2.58%; Scheme 8 - 1.64 to 4.45%; Scheme 9 - 2.66 to 11.77%; scheme 10 - 2.33 to 9.94%.The results of experimental studies indicate that when the proposed methodology of the logistic approach, using the "white box" based on the company "Inter Trans Logistic" to international container transportation of goods in relation to the application of the company "Agricultural Holding August" for transportation, the scheme 2 sequence o

The paper deals with analysis of properties of synchronous motor with external permanent magnets rotor. The mathematical analysis and equivalent circuit of permanent magnet synchronous motor (SMPM) is presented. In the parts of the paper the electromagnetic design, construction design and FEM Simulation of a SMPM is described and its properties are analysed. In the paper the results of simulation in Matlab/Simulink of torque, speed and current on the base mathematical model are shown.

The paper deals with a proposal for circuit configuration of series-series (SS) compensated wireless power transfer (WPT) system with reduced voltage stresses on compensation capacitors. Nowadays, a huge effort is given for the development of reliable, efficient and robust wireless charging systems and therefore the circuit configuration and component selection are crucial to meet suitable operational characteristics. For this purpose, the current trends in WPT systems are outlined in the first section. Next, the analysis of frequently utilized WPT system configuration is provided and the most critical issues related to practical utilization are discussed. Consequently, the proposal of how to eliminate negative aspects is given. All theoretical statements are supported by mathematical apparatus of the proposed system and consequently by the simulation analysis.

It was established that the polymeric component of the organomineral modifying complex changes the nature of the super-molecular structures in the activated cement system - at optimal filling, globules decrease in size preventing the phase surface diffusion, which contributes to increase of the waterproofness of modified concrete. When introducing a modified cement system into the concrete mixture, the reduction of the open porosity to 3-5%, depending on the composition, has been achieved. Conducted tests for water resistance and frost resistance of the repair layer of concrete showed that the modified concrete corresponds to the mark on water resistance W14 and the brand on the frost resistance F300. The developed technology of physico-chemical activation of the cement system allows the use of conventional cement for obtaining durable concrete of special purpose, which allows to reduce the cost of such concrete by 27-34%.

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 are only minor. The different states of the surface before the plasma nitriding result into the similar thickness of the compound layer. Furthermore, the underlying diffusion of near the surface layer state is different.

Activity-based costing is one of the procedures that proved to be very suitable for the financial management of warehouse activities in the automotive industry. Accurate and up-to-date data enables managers to properly plan and manage all the warehousing related activities in the automotive industry. In the activity-based costing approach, overheads costs are allocated in relation to specific logistics activities of the company. The aim of the article is the application of activity-based costing to the logistics cost calculation for warehousing in the automotive industry. The article focuses on the practical application of activity-based costing to the logistics cost calculation for warehousing in the automotive industry to a particular logistics service provider. It highlights the positive and negative use of this method in the practical case study, which is one of the major qualitative scientific methods. The resulting effect of using the activity-based costing method should be to refine the information that is used for the decision-making problems of the top management of the logistics service provider.

Elimination of seasonality temperature trends in a structural health monitoring of bridges is considered in the article. On example of a beam bridge, eigenfrequencies are plotted against seasonal fluctuations of environmental temperature. Next, analysis of a time series, formed from a data of frequency changes in the bridge, was made. To describe the time series, two different methods were implemented: ARIMA model based on a statistical relationship between the data and LSTM model of a recurrent neural network.

The number of alternatively powered vehicles in Poland and EU is growing steadily. Different type of vehicle drive trains determine variations in their performances from economical and environmental technological aspects. The aim of this paper was to investigate the cost efficiency and environmental aspects of midsize passenger cars equipped with different drive train technologies: conventional, hybrid, electric and LPG fueled engine. To this purpose, the Total Cost of Ownership (TCO) method was used. Calculations were carried out by AFLEET Tool. The results show that the LPG fueled car has the lowest TCO, while the cars equipped with electric drivetrain indicate the highest TCO. However the electric car recorded the lowest cost of air pollutant emissions and externalities costs.

The main goal of this paper is to analyse recent trends in freight transport volumes as well as their relation to socio-economic and infrastructural variables, in the case of the following major European countries: France, Germany, Italy, Poland, Spain and the United Kingdom. This analysis refers to the period 2005-2016, so that years affected by the global economic crisis, which shows its peak in 2009, are taken into account. This research demonstrated that not all the countries under study show a strong relation between freight traffic and GDP as it could have been expected based on well consolidated experiences and studies. Moreover, other relations are investigated, with mixed results, between the freight traffic volumes and the extension of the rail and road networks as well as oil price data.

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 value is 0.84g, with angular displacement relative to the transverse axis for the extreme from the anchor point of the wagon body - is 0.1 g, with angular displacement around the longitudinal axis for the extreme from the bulwark of the body of the wagon - is 0.24g. The conducted researches will enable increased efficiency of operation of open wagons through international transport corridors.

This paper deals with maraging steel, as a prospective material for the 3D printed lightened structural parts of transport means. Direct Metal Laser Sintering technology was tested for creation of a thin-wall structure with defined internal geometry. The referential samples prepared by the DMLS technology were examined under quasi-static and high strain rate loading using a servo-hydraulic testing machine at strain rates up to 1400 s-1. Microstructural analyses served for evaluation of structural homogeneity and metallurgy quality, including the influence of crystallization gradient. The stabile ductile fracture mode was proven by fractography analyses, even at a maximal strain rate. The post-impact tests were conducted to evaluate the local residual plasticity by indentation tests.

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 of selected features is analysed, as well.

The property of railway track to resist the irreversible deformation for a long-term operational loading considerably depends on the ballast layer. The ballast layer is the element of a railway track whose mechanical properties and state are formed in-situ with the help of the ballast cleaning, tamping and distributing machines. The varied properties of the ballast material to obtain the form during the maintenance and retain it during the operation are equally important for the ballast layer. The control over the processes of the ballast consolidation and deconsolidation by means of measurement methods could potentially provide great possibilities for improvement of its properties both during the maintenance and operation. The paper deals with an experimental study of the railway ballast consolidation and deconsolidation processes under the vibration loading of the sleeper. A non-destructive measurement method is proposed to investigate the distribution of the ballast consolidation along the sleeper. The method is based on the measurement of time of mechanical wave propagation. Modern low-cost sensors and powerful microcontroller techniques enable creating smart measurement systems for automatic multi-point data acquisition, online processing and statistical estimation of the ballast consolidation distribution.

Track-side inertial measurements on common crossings are the object of the present study. The paper deals with the problem of measurement's interpretation for the estimation of the crossing structural health. The problem is manifested by the weak relation of measured acceleration components and impact lateral distribution to the lifecycle of common crossing rolling surface. The popular signal processing and machine learning methods are explored to solve the problem. The Hilbert-Huang Transform (HHT) method is used to extract the time-frequency features of acceleration components. The method is based on Ensemble Empirical Mode Decomposition (EEMD) that is advantageous to the conventional spectral analysis methods with higher frequency resolution and managing nonstationary nonlinear signals. Linear regression and Gaussian Process Regression are used to fuse the extracted features in one structural health (SH) indicator and study its relation to the crossing lifetime. The results have shown the significant relation of the derived with GPR indicator to the lifetime.

The aim of this study is to analyse the advertising strategy on the transportation and storage market in the Czech Republic. The study provides information and knowledge of seasonal advertising scheduling by answering three research questions. The statistical analysis is based on a research sample of 840,204 advertisements aired in 2013-2017. The results of the study show different scheduling patterns of subcategories in the transportation and storage market. They also point out that subcategories in the transportation and storage NACE category are different. Therefore, marketing researchers should take this knowledge into account in their generalisations.

Impact of applied current density during the plasma electrolytic oxidation (PEO) process on corrosion resistance of AZ31 magnesium alloy was studied. The PEO coatings were prepared using four different current densities with values of 0.025 A/cm2, 0.05 A/cm2, 0.1 A/cm2 and 0.15 A/cm2 in electrolyte consisting of 10 g/l Na 3PO4.12H2O and 1 g/l KOH. Morphology and chemical composition of the coatings was examined using the scanning electron microscopy and EDS analysis respectively. Electrochemical characteristics of ground and coated samples were measured by means of electrochemical impedance spectroscopy (EIS) in 0.1M NaCl solution. Obtained data in form of Nyquist diagrams were analysed by equivalent circuit method. Results of experiments showed that value of applied current density had significant effect on protective performance of the PEO coatings prepared on AZ31 magnesium alloy surface.

The article presents numerical simulations with regard to determining the impact of the ionospheric and tropospheric delays on a radar-aircraft slant distance measurement. During the first experimental test, numerical calculations were made, showing the relationship between the ionosphere correction and the zenith angle in order to determine the measurement error of a radar-aircraft slant distance. During the second experimental test, numerical calculations were made demonstrating a relationship between the tropospheric correction and zenith angle in order to determine a measurement error of a radar-aircraft slant distance. The experimental test was conducted for the primary surveillance radar AVIA-W located on the grounds of the military aerodrome EPDE in Deblin. Based on the conducted research tests, it was found that the impact of the ionosphere delay can cause an error in a radar measurement above 4m. Moreover, influence of the troposphere delay can cause an error of a radar measurement by approximately 0.2m. The numerical simulation made in this research study may be used in the radiolocation of moving objects, as well as the GNSS satellite navigation in aviation.

The Friction stir welding (FSW) is a complex process, depending on many factors: machine, clamping device, material and tools. Parameters that have a direct impact on the quality of the joint include the rotational speed, welding speed, clamping force, geometry and tool plunging depth. The paper presents the results of experimental studies concerning the effect of tool pin length on the microstructure and mechanical strength of joints of thin sheets made of Al 7075 alloy. A tool with an adjustable pin with concave shoulder was used to weld the joints. Different pin lengths were used, which were selected with respect to the thickness of the welded joint. The specimens were subjected to visual evaluation, metallographic tests and mechanical strength testing. The results indicate that the pin length has a decisive effect on the microstructural changes in the joint and thus influencing the strength of the FSW joints.

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 influence on the acceleration amplitude. The limits of acceleration due to the ballast stability and the traffic safety are evaluated.