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This article considers the trunk lines, connected with the feeder region as the external environment for the system - feeder lines (its subsystems are container flows, ports and container ships). Hub ports are considered to be the boundary of the system and the external environment. Thus, mathematical models were simulated for the two levels. At the first level, container flows are determined (based on statistical data), which enter and exit the hub. At the second level, the mathematical model allows to find for the feeder line: volumes of container flows, the total capacity of the ships which serves the cargo, and parts of the distribution of this capacity between feeder ports.

This paper presents a novelty approach to usage of the fiber-optic phase-based sensor in railway transportation. We designed and tested the real deployment of this sensor working on the principle of light interferences within optical fibers. The proposed construction of the sensor allowed to increase the sensitivity and thanks to this can be detected and calculated individual axles and wheels of tram vehicles. We performed long-time period measurements (April to September 2019) in diverse climatic conditions, including measurements of 642 tram passages (several different construction types) in real urban traffic. The detection accuracy level was slightly above 99.4 %.

This article focuses on optimisation of the distribution routes for a company that produces carpets, floor coverings and tapestries. The optimisation process is based on operational research methods including, without limitations, Mayer's method and the single linkage method. The obtained results are subsequently compared to the current situation and evaluated in terms of time and costs. The conclusion provides the optimised economic solution.

This paper presents a method based on Artificial Neural Networks for estimation of the vehicle speed. The technique exploits the combination of two tasks: a) speed estimation by means of regression neural networks dedicated to different road conditions (dry, wet and icy); b) identification of the road condition with a pattern recognition neural network. The training of the networks is conducted with experimental datasets recorded during the driving sessions performed with a vehicle on different tracks. The effectiveness of the proposed approach is validated experimentally on the same car by deploying the algorithm on a dSPACE computing platform. The estimation accuracy is evaluated by comparing the obtained results to the measurement of an optical sensor installed on the vehicle and to the output of another estimation method, based on the mean value of velocity of the four wheels.

The impact of the e-economy has been observable in almost all the sectors of the national economies of the states in the last few years. The growing influence of this phenomenon is due to development of the Internet, which has already become a viable part of almost all the business activities including buying and selling. Therefore, it can be assumed that the area of e-commerce will have an increasing impact, not only on national economic development, but on the express mail market, as well. The content of the article is designed to provide a comprehensive view of the interdependence between the level of economic maturity (the GDP gross Domestic Product) per capita in the PPS (Purchase Power Standard) indicator), development of the e-commerce (indicator B2C (Business to Customer) e-commerce turnover) and the number of express deliveries. Identifying the influence between the aforementioned indicators, it will be possible to take certain measures to support the development of the e-commerce market.

The article deals with vacuum casting technology and especially with the assessment of the influence of the tempering temperature of silicone molds on the dimensions of future castings. The aim was to evaluate the actual size of the castings, using different tempering temperatures of the molds and different casting materials. After examining the resulting dimensions of the individual castings, a procedure was established by which these effects could be minimized. In the end, a test of the proposed procedure is performed, which confirmed its correctness.

The paper presents the results of a test on a composite bridge girder of a length of 42.0 m, which was performed to assess its resistance, stiffness and crack resistance. Composite reinforced concrete beam with three blocks is joined by the two monolithic joints. When testing a beam with monolithic joint in terms of stiffness, crack resistance and strength, a load of 943.5 kN was achieved without cracking, which is 26.8 % higher than the required one.

While performing the research of the vehicles operating characteristics in real operating conditions, a question of creation or correction of a movement driving cycle always appears. An absence of a mathematical model rather complicates the research process and makes a quick correction of movement conditions impossible. To solve the given problem, it was proposed to model a driving cycle using the Bezier curves. As a result of this research, it is stated that the most advantageous is to use the Bezier curves of the second and third degrees. During the analysis of results of driving cycles modeling and their comparison to the standardized and real movement cycles, a satisfactory coincidence of results was obtained. The conducted thematic research confirms the previous results, directed to creation of a universal dynamic model of a vehicle's driving cycle.

The article presents results of the laboratory studies of the impact of the child seats mounting method on the vibration comfort of children transported in them. The tested child seats were mounted forward facing the rear seat of a passenger car. The A seat was fastened with the ISOFIX base, while the B seat was fastened with standard car seat belts. During the tests, values of the vertical vibrations were measured on the seat of the child seat, the rear seat of the vehicle and the ISOFIX base. It was noted that the analyzed system, may be characterized by two different vibration transmission chains, which depend on the child seat mounting system (classic seat mounting system and ISOFIX system). These studies show the negative impact of using the ISOFIX base, which is confirmed by the Root Mean Square (RMS) values and the Vibration Dose Value (VDV), determined for the "A" seat secured with the ISOFIX base that were higher than the RMS and VDV for the "B" classic mounted seat.

Road transport have significant impact on regional economic and social development, but one can also point out a number of its disadvantages, which include environmental pollution. The paper presents measurements of fumes exhaust emissions of a passenger car with a significant operational mileage. The tests were carried out in a laboratory on a chassis roller dynamometer using various driving cycles. To determine the exhaust emissions, data on the mass of air flowing through the intake manifold was used, among others. The work also describes an example of own driving cycle developed based on urban driving in Lublin, Poland.

The paper is devoted to analysis of modern directions of innovation-investment formation of intelligent computer networks that control the fast-moving technological processes of electricity supply. It is based on the conclusion that the problem of increasing the productivity of information exchange between information resources and consumers is dominant. A method for increasing the efficiency of information exchange is proposed as a search for the rational location of a new node and the organization of such a set of its connections among the whole set of nodes of the computer network, which provides a minimum average topological distance. Mathematical models of effective topological organization of connections in computer network of power consumption control at the level of traction substations, electric power distances and the railway in general are proposed.

The article discusses the possible impact of disasters on functionality of the transport critical infrastructure elements by overcoming their resilience. The aim of the article is to provide an appropriate approach to the resilience measurement through understanding of this close relationship. It was achieved by using combination of (1) a decisiontheoretical approach based on Influence Diagrams, which was used as a tool to model functionality disruption level of transportation network elements after disaster impact and (2) the time decomposition of the functionality disruption duration of these elements. Based on this approach, the transportation network element resilience assessment was conducted in form of the transportation element resilience loss. The proposed approach is intended to be applied to the critical infrastructure elements rather than to the transportation network as a whole.

To calculate the stress-deformed state of road-tanker metal structures during the liquid cargo transportation, the solution for bending axially and symmetrically loaded circular plates is proposed, which is based on the theory of elasticity approach. Dependencies for calculating stresses and displacements under arbitrary load law and support type are substantiated. Deformation of the support under the action of axisymmetric loading leads to appearance of a temperature field.

The method of investigation of the non-linear vibrations of the wheel vehicles with the guided cushioning system has been developed. It is based on the idea of the perturbation methods combined with the theory of special periodic Atebfunctions. All these made possible to obtain analytical relations, which describe the characteristic features of the cushioning area vibrations. These relations can be the basis for creation of the software product of the guided cushioning system with the purpose to minimize the dynamic loadings on the transported people and cargo and to increase the stability characteristics of the vehicle movement along the curvilinear areas of the bump road.

The article presents results of verification of the kinematic measurements usefulness for precise real-time positioning RTK in the local reference system. These measurements allow for continuous RTK measurements in the event of temporary interruptions in radio or internet connections, which are the main reason for interruptions in RTK kinematic measurements and cause a decrease in the reliability and efficiency of this positioning method. Short interruptions communication are allowed during the loss of the key correction stream from the local RTK support network, so the global corrections obtained from the geostationary satellite are used. The aim of the article was to analyze the accuracy of measuring the position of moving objects. Practical conclusions were formulated according to the research subject, the presented mathematical models, the experiment and the analysis of the obtained results.

The work is aimed at the construction of an algorithm for studying the equilibrium states of a reinforced plate near critical points, using the first (cubic terms) nonlinear terms of the potential energy expansion. Using geometrically nonlinear analysis of displacement, deformation and stress fields, the Eigenforms of buckling were calculated and bifurcation solutions and solutions for equilibrium curves with limit points were constructed depending on the initial imperfections.

The aim of the article was to present the characteristics of conducting bathymetric measurements of a water area by means of a manned watercraft. The survey was performed in a body of water that is relatively shallow and frequently used by water sports enthusiasts. The results of the study described the shape of the bottom of the marina studied and identified dangerous places for vehicles moving on it. It was proved that using a manned vessel is dangerous or impossible to make measurements near the pier where the yachts were moored and areas where the depth was less than 1 meter. Using the points recorded by the Lowrance HDS Carbon 9 echo sounder, the authors of this paper generated 2D and 3D maps of the measured reservoir with the depths plotted on them. The created studies can be used when developing navigational aids to facilitate the driving of water vehicles.

The paper presents an analysis of the noise recorded by the two road traffic noise-monitoring stations. The stations were located in Kielce, Poland, at the road No. 74: on the outskirts of the city and near the center. Based on the experimentally recorded data, an equivalent sound level and acoustic pressure were determined for three sub-intervals of the day: nights, days and evenings. The conducted analyses showed that the average annual values (depending only on the time sub-intervals) of the median do not differ significantly between stations. A similar conclusion can be drawn based on simulations of the median and the C90 percentile of the sound pressure . However, the maximum relative differences in the C99 percentile of the acoustic pressure between stations are around 13%. The maximum relative differences in median pressure between stations are around 15% (for the time sub-interval nights).

The study deals with determination of the dynamic loading on the frame of a tank car with closed composite center sill filled with elastic-viscous filler. It has been found that the measures for improvements can decrease the dynamic loading of the frame by 3.5 % in comparison to that of the structure without a filler. The strength calculation of the frame of a tank car is also presented. It was found that the maximum equivalent stresses occurred in the contact area between the center sill and the body bolster; they amounted to about 284.7 MPa and did not exceed the allowable values. The computer modelling of the dynamic loading of the tank car frame was also conducted. The numerical values of accelerations and the distribution fields of accelerations in the frame of a tank car were determined. The results of the calculation showed that the hypothesis on the adequacy was not rejected. The natural frequencies and oscillation modes of the tank car frame were also determined.

The wear of cutting elements of auto graders allowed in practice causes an increase in the cutting force by 3 to 4 times, the energy intensity of the cutting process by 1.4 to 3 times, the cost of soil development by 8 to 15 % with a decrease in productivity by 10 to 30 %. This increases the stress state of the entire machine and reduces its operational reliability. Excessive wear of cutting elements leads to economic inexpediency or practical impossibility of further operation of machines.

This paper deals with implementation of artificial neural network in the maximum power point tracking (MPPT) controller algorithm for modern household where electric vehicle (EV) was purchased. The proposed MPPT algorithm was designed to achieve the best possible efficiency of the MPP (maximum power point) tracking and the best possible energy harvesting to charge the EV's battery. The artificial neural networks have strong advantage in fast input to output response of signals and the finding of MPP is faster than in commonly used algorithms. In this article, the optimised simulation model based on artificial neural network will be introduced. The proposed artificial neural network algorithm was designed for non-shielded photovoltaic panels.

The paper presents the methodology of designing the production process of a new product from the point of view of the criterion of the assembly operations technology (Design for Assembly - DFA) in the automotive industry. The article describes methods and techniques used during the implementation of a new product into production. The impact of the methods on improving the assembly technology of a complex product is described. Suggestions for improving for unit and small series production are presented.

Mathematical model of transmission of movement of an electric drive system that includes long elastic elements, including the non-linear relation between tensors of strength and deformation is presented in this article. Mentioned type of transmission is applied in the tasks related to special-purpose transport. A method that is based on integral modification of variational Hamilton-Ostrogradsky principle was applied for the presented model. Results of the computer simulation of oscillatory processes in transmission of movement of an electromechanical system are presented in the article.

The influence of the aggressive environments of river water, seawater, oil, petrol and sodium hydroxide on the impact strength of epoxy-polyester composite was investigated. Testing was conducted by two different methods. It was determined that the impact strength of specimens that were kept at air was W' = 4.2 kJ/m² (by the second method - W'' = 7.0 kJ/m²). The energy spent on destruction of the control specimen was E = 0.92 J. The main regularities of the crack propagation process in the studied material were found and qualitatively described. The time of a crack propagation (τ = 0.16 μs) was determined. The maximum load, which leads to destruction of the specimen was P_max = 2.47 kN. The comparative analysis of investigated specimens was conducted by the IR-spectroscopy method. It was found, that the biggest decrease in material properties was observed for the specimen that was kept in the petrol environment.

The paper presents an analysis of an actual problem related to dynamic effects to road bridges due to travelling a heavy vehicle over the bridge. Numerical simulations of the dynamic response are applied on a fictitious simple beam of the length L_b = 52 m with an artificial irregularity at mid-span, corresponding to a characteristic span L_(b5) = 52 m of the ten-span continuous box girder bridge. A heavy four-axle truck m_v = 32 t is used for dynamic excitation, travelling over the bridge at passing speed of 70 km / h. The obtained results are compared to results of the experimentally tested ten-span continuous pre-stressed reinforced concrete girder bridge at the same speed.

Automobiles with internal combustion engine using diesel fuel have large harmful emissions of nitrogen oxides and soot, which affect the health of the population and especially children and carbon dioxide, which is dangerous for the planet as a whole. Biodiesel is used in Europe as an additive to diesel fuel to reduce soot emissions (including carcinogens), as well as to improve the balance of carbon dioxide on the planet. Using the biodiesel in internal combustion engines tends to show higher nitrogen oxides emissions compared to diesel. In this paper, the impact of flame temperature, ignition delay and density on NOx formation of biodiesel and its component for both stationary engine and automotive engine were analysed. Emissions of nitrogen oxides increase with increasing load. In no-load modes, biodiesel shows lower emissions of nitrogen oxides than diesel.

This paper presents an analysis of the strength of a prototype test rig for testing rotors of unmanned aerial vehicles. Digital design software was used for the design work that covered the creation of a virtual model of the test rig and strength analysis of its key elements. The paper discusses the test rig solutions, applied to date, of the small main rotor research. From the assumed operational parameters and structural parameters of the rotor, the main forces acting on the designed structure were determined: lifting force, reaction torque and empty mass of the test rig. Suitable actuators of the control system enabling the regulation of the total pitch and periodic pitch of the rotor, within the full range of the angle of attack, were selected for the rotor under test. The FEM (Finite Element Method) strength analysis was carried out for the proposed support structure and the correctness of the design was verified.

The study object is a prototype of a composite bridge prestressed concrete beam with a length of 42.0 m for road bridge desks for perception of impact from motor vehicles in the form of A14, NK-120 and NK-180 loads.

The problem considered is to estimate the image position of a spatially extended object. It is assumed that the shape of the image intensity is a priori unknown, but it can be predicted with some error. In order to synthesize the estimate of the image position, the quasi-likelihood version of the maximum likelihood method is used. Behavior of the signal function in the neighborhood of the real image position is studied. Characteristics of the resulting estimate, such as bias and dispersion, are found by means of the local Markov approximation method. Influence of non-uniformity of the received image intensity upon the estimate accuracy is demonstrated by an example of receiving the rectangular image with linearly varying intensity.

Air transport industry is one the many sectors significantly impacted by the COVID-19 pandemic. Travel restrictions and bans resulted in reduction in aircraft operation. Airlines have no option than to limit their services by grounding their fleet: as of April 2020, out of 22,000 passenger aircraft around the world, almost 14,400 were grounded [1]. Airport operators are trying to accommodate most of the grounded aircraft by utilizing their main operational space as aprons, taxiways and runways. The limited space at airports often means that aircraft have to be parked in non-standard positions, which may affect the airport daily operations. While planning aircraft parking, safety is the top priority. The effect of long-term load was not considered in the pavement design and could result in increased pavement maintenance requirements. Airport operators must also reflect aircraft maintenance needs in terms of engines, hydraulics, braking system, cabin interior and others.