The development of air transport affects elements of the aviation fuel market. In recent years an increase in both the number of passengers and the number of passenger operations has been observed. This phenomenon also concerns passengers and the number of operations served by Polish airports which translates into more and more fuel consumption in Poland. The authors of the study tried to approximate the characteristics of aviation fuels used in various types of aircrafts. The most important of them, from the perspective of the Polish aviation sector, include Jet. This type of fuel plays a key role in civil aviation. In the article, the enterprises operating in the analyzed sector were also reviewed. The empirical part of the article is devoted, in turn, to the analysis of changes in air passenger transport in Poland and changes in Jet fuel prices on the Polish fuel markets. The conducted research shows that the dynamics of changes in the number of passengers, as well as the number of passenger operations at Polish airports were characterized by an upward trend, and the increase in the number of passengers was driven not only by a larger number of available flights, but also by such factors as: increasing the capacity of aircraft and increasing the fill rate for seats. The authors have also attempted to examine the strength of dependence between the number of passengers deciding to use Polish airports and Jet fuel prices, which in recent years have undergone significant fluctuations. For this purpose, the value of Pearson’s linear correlation coefficient was used and the analyzed period covered the years 2011–2017. The data on passenger traffic used in the study came mainly from periodic reports prepared by the Civil Aviation Office (ULC).
Embedded software and dedicated hardware are vital elements of the modern world, from personal electronics to transportation, from communication to aerospace, from military to gaming, from medical systems to banking. Combinations of even minor hardware or software defects in a complex system may lead to violation of safety with or even without evident system failure. a major problem that the computing profession faces is the lack of a universal approach to unite the dissimilar viewpoints presented by computer science, with its discrete and mathematical underpinnings, and by computer engineering, which focuses on building real systems and considering spatial and material constraints of space, energy, and time. Modern embedded systems include both viewpoints: microprocessors running software and programmable electronic hardware created with an extensive use of software. The gap between science and engineering approaches is clearly visible in engineering education. This survey paper focuses on exploring the commonalities between building software and building hardware in an attempt to establish a new framework for rejuvenating computing education, specifically software engineering for dependable systems. We present here a perspective on software/hardware relationship, aviation system certification, role of software engineering education, and future directions in computing.
The social and political transformations Russia underwent in the 20th century were also reflected in the sphere of imagery. This also refers to the imagery of movement and means of transport. The process of linking the imagery of means of transportation with the political doctrine in force is mostly visible in the period of Soviet rule, in particular in the interwar period when the foundations of this rule were laid. Then, aviation was to become one of the strongly ideologized means of transport. The ideologization process occurred at various levels, starting from onomastic procedures through advertising and linking aviation and Soviet rule within artistic and literary conceptualisations. In Soviet culture, an aeroplane or a rocket were not merely means of transport but the means by which the expansion of communist ideology globally was supposed to be facilitated.
This work presents a numerical simulation of aviation structure joined by friction stir welding, FSW, process. The numerical simulation of aviation structure joined by FSW was created. The simulation uses thermomechanical coupled formulation. Th model required creation of finite elements representing sheets, stiffeners and welds, definition of material models and boundary conditions. The thermal model took into account heat conduction and convection assigned to appropriate elements of the structure. Time functions were applied to the description of a heat source movement. The numerical model included the stage of welding and the stage of releasing clamps. The output of the simulation are residual stresses and deformations occurring in the panel. Parameters of the global model (the panel model) were selected based on the local model (the single joint model), the experimental verification of the local model using the single joint and the geometry of the panel joints.
One of the little described problems in hydrostatic drives is the fast changing runs in the hydraulic line of this drive affecting the nature of the formation and intensity of pressure pulsation and flow rate occurring in the drive. Pressure pulsation and flow rate are the cause of unstable operation of servos, delays in the control system and other harmful phenomena. The article presents a flow model in a hydrostatic drive line based on fluid continuity equations (mass conservation), maintaining the amount of Navier-Stokes motion in the direction of flow (x axis), energy conservation (liquid state). The movement of liquids in a hydrostatic line is described by partial differential equations of the hyperbolic type, so modeling takes into account the wave phenomena occurring in the line. The hydrostatic line was treated as a cross with two inputs and two outputs, characterized by a specific transmittance matrix. The product approximation was used to solve the wave equations. An example of the use of general equations is presented for the analysis of a miniaturized hydrostatic drive line fed from a constant pressure source and terminated by a servo mechanism.
The aim of the article is to determine the main factors responsible for development of Podkarpackie Voivodeship in the last 15 years and to answer the question whether they were suffi ciently strong impulse to divert the region from its development model. The main method used for identifying the factors that determine the development of the region was individual, in-depth interviews with the main actors on the regional scene, supported by desk research analysis (of the voivodeship’s strategic and operational documents) and statistical data analysis (Central Statistical Office and Eurostat). The research highlights the importance of the immobile and intangible development factors – a high quality of strategic thinking of local and especially regional authorities and consistent implementation of development policies, a high level of social capital, extensive networks and the ability to co-operate – which have helped to eliminate the limitations resulting from the weakness of other factors.
Coordinate Measurement Machines (CMMs) have been extensively used in inspecting mechanical parts with higher accuracy. In order to enhance the efficiency and precision of the measurement of aviation engine blades, a sampling method of profile measurement of aviation engine blade based on the firefly algorithm is researched. Then, by comparing with the equal arc-length sampling algorithm (EAS) and the equi-parametric sampling algorithm (EPS) in one simulation, the proposed sampling algorithm shows its better sampling quality than the other two algorithms. Finally, the effectiveness of the algorithm is verified by an experimental example of blade profile. Both simulated and experimental results show that the method proposed in this paper can ensure the measurement accuracy by measuring a smaller number of points.