Vol. 8 No. 1 (2023)

Published April 30, 2023

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Materials Sciences

  • Efficiency of the Machining Process of Circular Shapes by Electrical Discharge Technology
    53-61
    Views:
    76

    Due to its high machining precision, EDM technology is nowadays very important in the production of high-precision parts for various industries. The high precision of the machined surface in combination with the ability to machine circular surfaces brings, in addition to several advantages, some negatives. The most significant negative of this machining technology is the relatively low productivity as well as the overall production efficiency. The latter is affected by many accompanying phenomena. The main accompanying phenomenon that contributes to the decline in the overall economic efficiency of EDM is the microgeometry errors that occur due to the non-homogeneity of the EDM process. Another accompanying negative phenomenon is the geometric accuracy errors of the machined surface, as a consequence of systematic destruction of the wire tool electrode, faulty interpolation in its guidance, and, last but not least, its vibration. These aspects consequently lead to the requirement for multiple applications of additional finishing cuts, which significantly reduces the overall economic efficiency of the machining process. Therefore, the experimental research aimed to search for options that can effectively help to achieve higher productivity but especially the overall economic efficiency of the machining process.

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  • Mechanical Testing of 3D Metal Printed Stainless Steel Specimens
    7-13.
    Views:
    89

    Additive manufacturing (AM) is a cutting-edge production method, which has come a long way since its first introduction in the ’80s. Back in the days its usage was very limited to stereolithography, and was only able to make weak structures, so it only worked for visualization. Four decades later it is one of the leading research fields in production areas, because of its flexibility and its ability to make almost any complex geometry. However, no matter how powerful it is, it is not omnipotent, there are certain size and shape restrictions even this method must apply to.

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Economics

  • A Domestic Investigation of Online Banking
    22-32
    Views:
    188

    Nowadays, the spread of digitalization is constantly increasing. The current rising generation is already a “digital native”. As part of digitalisation, mention should be made of the Internet, which has been given a prominent role in our daily lives. We search for information on the Internet, we communicate, we buy. Due to these factors and the pandemic in 2020, internet administration has become a priority. Banks need to constantly adapt to meet their needs, promoting convenient, home banking. In the course of our research, we focused on this continuous adaptation and the resulting improvements. The research focused on the Internet and mobile banks of large Hungarian banks. Sampling took place over 2 periods. Among the primary research tools, we chose document analysis, and netnography. In the research, we compared the functions available on the platforms, the consumer perception of mobile banks and other variables. Based on the results obtained during the research, it can be stated that domestic banks are constantly developing their application along different trends and trying to adapt to changing needs. Serious changes had to be made in the mobile banks of most large banks, even with the permanent elimination of their former mobile banks. Changes can have a strong impact on consumers, who are often more likely to have a negative view of them. Digitalisation is also particularly important in this sector. The study contains the details of the course work prepared for the Scientific Students’ Associations Conference.

    hu
    91

Management Sciences

  • The Dunning–Kruger Effect in Knowledge Management Examination of BSc Level Business Students
    14-21
    Views:
    164

    The Dunning-Kruger effect (DKE) in higher education evaluation is one of the current research areas of psychology, educational science, and management science (in our case). Its importance is that the less prepared one is, the less accurately one can judge what performance is expected of him. What is more, he will err more and will overestimate himself. The present study aims better to understand the phenomenon with new, small-sample empirical results. The study is part of a research series that has been ongoing at the University of Debrecen since 2015. It not only quantitatively expands the literature but also includes the course of Knowledge Management among those examined. During the research, students were asked both before the examination (N = 63) and after the examination (N = 76) to guess how many points they would achieve on a multiple-choice test. It supports the presence of DKE, both in the case of pre-examination and post-examination self-evaluations. Using four multivariate linear regression models, we examined whether the sign value or absolute value of the errors made during the guesses show a correlation - in addition to the available control variables - with the test score. Our results showed that the more accurate the pre-examination and post-examination estimations were, the higher the students' actual score was, while the less they tended to overestimate their preparation. This supports the presence of DKE, both in the case of pre-exam and post-exam self-evaluation.

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Sport Economics

  • Wearable technology usage among students of the University of Debrecen
    33-47
    Views:
    109

    The lack of physical activity and the growing prevalence of a sedentary lifestyle are urgent public health problem worldwide. The problem is also typical of the young population, especially university students, who spend most of the day in a sitting position. Technological development is one of the catalysts for the rise of a sedentary lifestyle, nevertheless, thanks to this, many devices have appeared on the market that can be used to encourage physical activity. The widespread of wearable activity tracker devices – wristwatches, wristbands – among the population shows a constantly increasing trend, with a parallel increase in the amount of data collected about ourselves (step count, calories burned, heart rate). The main goal of the present study derives from the recognition of the gap in this field in the domestic sports science literature therefore our focus is on modern information technology tools in the dimension of physical activity. The aim of this study is to assess the attitudes of the university student population towards activity-tracking devices. We conducted a cross-sectional online quantitative survey (questionnaire) among DE GTK students. 340 people filled out the questionnaire correctly. In addition to descriptive statistics, parametric and non-parametric tests (Pearson's chi-square test, Fisher's exact test, t-test, Mann-Whitney test) were used to examine the relationships. The results of the statistical tests were considered significant if p<0.05. We performed the distribution of the variables using the Kolgomorov-Smirnov test. The majority of respondents (55%) have already tried some kind of wearable device that measures physical activity. Every third student (34%) are currently using their device. Those who have not tried these devices so far indicated the price as the primary deterrent. 32% of the students plan to invest in such a device in the future. 39% of device users use an activity tracker bracelet, while 61% use or used a smartwatch. In terms of sex, we did not find any differences in asset ownership. The primary goal of the students (66.8%) was to track their physical activity. The most frequently used function was tracking the number of steps, indicated by 81% of the respondents, followed by heart rate measurement (67%). Most of them (69%) set some kind of goal regarding their number of steps. According to every third student, they moved more as a result of the device and managed to maintain the increased level of physical activity. 44% of the students claimed that their physical activity did not change despite using the device. Students tend to disagree with the positive statements related to the devices in connection with a healthy lifestyle. Although the present study suggests that wearable devices have an impact on students and they track their measured data, it is questionable whether the devices themselves are enough of an incentive for students to develop a healthier lifestyle.

    hu
    29

Mechanical and Vehicle Engineering

  • Simulation of BLDC Motor Drive Systems for Electric Vehicles Using Matlab Simulink
    48-52
    Views:
    158

    The defining scientific developments of our time would not have been possible without the use of simulations. The aim of the research is to create a simulation of a BLDC motor. When creating a simulation, great emphasis must be placed on defining the purpose of the simulation. This basically determines the structure and complexity of the model. The model discussed here was created so that an optimization task could be defined more precisely by inserting it as a sub-model into a vehicle dynamics model. Scalability was another aspect, that is, to be able to increase the accuracy of the model with measured data in the future, as well as to be able to validate it. During the research, a BLDC motor efficiency map generation program was created, as well as an environment for testing the generated data. The created system gives researchers the opportunity to use a shape-correct efficiency model when simulating a BLDC motor even without measured data. This makes it possible to discover real relationships between model parameters when performing optimization.

     
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  • Application of Topological Methods in the Development of Vehicle Components
    67-75
    Views:
    73

    Many areas of the industry are characterized by continuous changes, which define new directions of development in product design. The development of computers and software, the spread of modern production tools and the development of material technology make it possible to expand traditional production technologies with modern processes. Integrated CAD systems have occupied their place in the product design and development process for decades, reforming classical design methods. Popular optimization procedures in integrated CAD systems, such as shape optimization, topological optimization and the new generative design process, provide effective solutions for design engineers in more and more industrial application areas. Experience shows that modern design methods can be used in many areas of industry. The appearance of metal powder printing and additive technology make it possible to test the designed prototypes or even to produce the final products. The following article aims to support the above with the help of a case study.

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  • Analysis of Structural Strengths Applied the Cableway Group
    62-66
    Views:
    54

    This paper will present the analysis of structural strengths for the cableway group. Three loading scenarios were analyzed. Each of these scenarios will be presented on the cableway group and explained with the intervening forces.

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  • Full-Scale Tests of Pipeline Girth Welds Under Complex Cyclic Internal Pressure and Static Bending Loading Conditions
    76-82
    Views:
    89

    The critical elements of high-pressure hydrocarbon transporting pipelines are often the girth welds, which are subjected to complex loads. The aims of our research and this paper are to introduce our full-scale pipeline fatigue and burst tests applying cyclic internal pressure and superimposed external bending stress on girth welds, furthermore, attracting the importance and the applicability of the investigation results. A unique testing system was built to study the behaviour of pipeline girth welds under simultaneous loads. The tests were evaluated using video camera recordings, internal pressure vs. burst time functions and failure pressure values.

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  • Numerical Modelling and Simulation of Sheet Metal Forming Process
    1-6.
    Views:
    117

    Simulation and modelling of sheet metal forming process are well common today in different industries (automotive, aerospace) and several research centers regarding its huge impact for both on production and reliability of the lifecycle of the equipment, and the quality of the product. However, to obtain the best configuration possible with the inputs parameters to achieve high level of production and increasing the durability of the tools needs some extra methods for the optimization for this problem using mostly finite element method cooperated with iterative algorithms based on Artificial Neural Network (ANN) [1]. Whereas this research is focused on modelling of stamping process of stainless steel AISI 304 to investigate to formability of the material, and studying the influence of the friction factor on the quality of the product as well the energy required for each set configuration.

     

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