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  • Study Habits of University Students
    109-117
    Views:
    86

    What kind of electronically available content can students prefer? We conducted a questionnaire survey in which we asked about the study habits of university students: where, how, with whom, when, how much, where do they study? Do they use problem-solving software? We need to find out about it, since learning habits and strategies have changed significantly in recent years. Taking into account the answers to the questionnaire, we draw attention to some activities that improve the quality of education.

  • Exhaust System Muffler Volume Optimization of Light Commercial passenger Car Using Transfer Matrix Method
    132-138
    Views:
    191

    Nowadays, the automotive industry is focused on weight and size reduction. Main advantage of this weight and size reduction are improving the fuel economy. The specific fuel consumption of a vehicle can be improved through e.g. downsizing area of heat loss, if we focus on vehicle with weight reduction. Weight reduction can be done by replacing material or by changing the size (dimensions) of components. In the present work we have focused on Audi A6 muffler, troubleshooting and optimizing the muffler by changing pipe length of inlet and outlet, also by replacing the original mesh plate to porous pipe. Based on optimization, prototype has been built with the help of 3D design tool CATIA V5 and the calculations of transmission loss (TL) have been performed by MATLAB. Plane wave-based models such as the transfer matrix method (TMM) can offer fast initial prototype solutions for muffler designers. The principles of TMM for predicting the transmission loss of a muffler was used. Result of this present study of an existing muffler has been analysed and then compared with vehicle level test observation data. Noise level have been optimized for new muffler design. Other literatures were played significant rule for validate our results.

  • Analysing the Possible Connection Between Dark Triad Personality Traits and Ethical Attitudes of University Students
    57-67
    Views:
    332

    In our paper we examined the possible connection between the Dark Triad personality traits and ethical attitudes among university students. The analysis of both topics has become the focus of interest in the past decades. Researchers consider the impact of many factors in the background of ethical attitudes and behavior. Among other things, personality is also a potential factor. The Dark Triad personality means the coexistence of the socially undesirable narcissism, Machiavellianism and psychopathy. Such people are characterized by self-love, aggression, the lack of guilt or conscience, so they are less likely to have ethical attitudes. In our research, this connection was examined by a questionnaire survey conducted among first year students of University of Debrecen Faculty of Natural Sciences and Technology and Faculty of Economics and Business. Respondents completed the validated Dirty Dozen questionnaire which was developed to measure Dark Triad personality and a questionnaire adapted from Lozier's research in which respondents were asked to evaluate school situations whether they are ethical or unethical and to what extent they are unethical. In our research, we were looking for significant relationships between the strength of the Dark Triad characteristics and the ethical judgment of situations. We also analyzed the differences between men and women and students of the two faculties.

  • Safety Index Based on Geometric Probability Is Proposed to Represent the Uncertainty of Soil Parameters for Spread Foundations
    43-52
    Views:
    140

    The overall factor of safety in geotechnics can be defined as the product of four partial factors of safety. One of these partial factors represents the uncertainty of the soil parameters. Based on geometric probability, a safety index is proposed to calculate the uncertainty of the soil parameters for spread foundations. Numerical examples have also been presented.

  • Simulation of Hot Rolling by Cellular Automata
    190-195
    Views:
    199

    Our research is focusing to one of the most complex and important production step of flat rolled products that is the simulation of hot rolling. During hot rolling two phenomena as work hardening and the process of regeneration of crystals has strong influence for physical properties of microstructure of aluminium alloys. It needs to be taken into account in case of rolling technology steps and development. When we talk about aluminium the dynamic softening in fact it is dynamic recovery that is followed by dynamic recrystallization. It goes in the same order of magnitude rate. But in steels the recovery has only a minor effect. Hot rolled and newly modified grain structure is influenced by these dynamic phenomena. Hot rolled grain structure goes through significant changes under further production steps like cold rolling and heat treatments. But aside from these intermediate production steps the microstructure that we get after hot rolling has significant effect for mechanical and grains structure of the final flat rolled product. Proper technology planning is essential that for cellular automata simulation method can ensure useable and good solution for the simulation of recrystallization.

  • Investigation of Aluminum Dross as a Potential Asphalt Filler
    445-451
    Views:
    122

    There is a great concern about utilizing different waste materials all over the world. Stockpiling in landfills is not a final solution, therefore researchers try to find alternative methods to utilize these materials [1-5]. One potential area may be road construction. Fillers are one of the most important components of asphalt pavements. It has a dual role. First of all, these fine grained mineral materials (d<0.063 mm) enhance the cohesion with bitumen. Second is to fill the gaps between the particles to produce more compact mixture [6]. The aim of this research is to reveal the possibility of utilization of aluminum dross as a potential asphalt filler. This material, which is a by-product of aluminum casting process, is produced in large quantities year by year and its storage in landfills is not a proper solution. Therefore, there is an increasing demand to utilize this material. During the research material structural tests were made, which can characterize the samples (limestone powder, dross), and the cohesion between bitumen and filler can also reveal. Particle size distribution, BET specific surface area and porosity were investigated. Scanning electron micrographs were taken and oil adsorption test were also made.

  • The Efficiency of Intellectual Capital as a Crucial Factor of Innovation
    419-428
    Views:
    262

    In today's global economy, there is a substantial shift from manufacturing to services, which challenges both economic policymakers, business stakeholders, owners, suppliers, competitors, and ordinary people: restructuring will encourage all economic players to learn how to adapt to new trends. That is why our research focuses on innovation and the ability of companies to create value. The IT sector is currently one of the fastest-growing and most innovative sectors within the service industry. The success of IT companies is greatly determined by their ability, how to make effective use of their intangible assets at their disposal, including intellectual capital, which is defined as a non-financial asset. So the question may arise: how is it possible to quantify and in monetary terms the intellectual capital of the companies to be examined? That is why, we calculated for the most successful Hungarian IT companies the widely recognized index, the VAICTM index, for which domestic calculations are not yet available. Indeed, this indicator eliminates the lack of information stemming from reporting standards by the methodology relying on publicly available financial reporting data. The indicator itself is a top indicator whose two main sub-indicators quantify the effectiveness of intellectual capital and physical capital.

  • Review on Construction Procedures of Driving Cycles
    266-285
    Views:
    290

    The goal of this paper is to give an overview of the literature of construction techniques of driving cycles. Our motivation for the overview is the future goal of constructing our own driving cycles for various types of vehicles and routes. This activity is part of a larger project focusing on determination of fuel and energy consumption by dynamic simulation of vehicles. Accordingly, the papers dealing with sample route determination, data collection and processing, driving cycle construction procedures, statistical evaluation of data are in our focus.

  • The Effect of annealing temperature on corrosion resistance and microstructure of Zr-Sn-Nb-Fe alloy
    420-424
    Views:
    126

    The Ti-2Al-2.5Zr titanium alloy plate in beta phase water quench at different times of the reentry after annealing is implemented while primary phase number and size distribution of samples are obtained. This research is carried out on corrosion behavior in 3.5% [mass fraction] NaCl solution. Experimental study showed that after the beta phase water quenching Ti-2Al-2.5Zr titanium alloyed after 500 oC annealing when partial recrystallization happened. There seems to be lots of tiny dispersion in the alloy that was annealed with its samples of six-party [HCP] structure of Ti, Zr, Al phase 2 with the dimension below 100 nm. Reaching 500 oC when the rate of annealing at a primary phase of the sample at 550 oC is low 90% of the primary phase is less than 100 nm. The changing of the rule of present decreasing also triggers little difference overall. Precipitation in the process of annealing Zr [Nb,Fe,Cr] 2is less that proves to be good for corrosion resistance.

  • The Role of Stocks in the Supply Chain
    515-526
    Views:
    1153

    Az ellátási lánc teljesítményét nagymértékben befolyásolja a szereplők készleteinek összetétele, nagysága, rendelkezésre állása. A végső fogyasztókért vívott versenyben kiemelt szerepe van a kiszolgálási színvonalnak, hiszen az ellátási láncok ugyanazokért a fogyasztókért vívnak versenyt, és a fogyasztók döntése leginkább e két tényező, mint a készlet nagyága és a kiszolgálás minőségétől függ. A tanulmány a kkv-k logisztikai problémáit feltáró kutatás része, melynek célja rávilágítani a jellemző nehézségekre, és azokra a kihívásokra, amelyek legtöbbször elkerülik a logisztikai- vagy ellátási lánc vezetők figyelmét. A fejlődő kkv méretű vállalkozások versenyképessége - ami magába foglalja a költségek nagyságát is, kapcsolódva a K+F tevékenységhez vagy vállalat növekedéshez – a lekötött tőke mértékével arányosan változhat, melynek jelentős részét képezik a készletek. A kutatásban résztvevő vállalat, a Diego Kereskedelmi Kft. készletezési politikáján keresztül kerül elemzésre a készletek összetétele, illetve a velük kapcsolatos kockázatok, illetve félreértések. A tanulmány célja továbbá a helyes megoldások elősegítése, melyhez szorosan kapcsolódik (az itt tárgyalásra nem kerülő) Lean megoldások támogató szerepe.

  • Neutral Inhomogeneity in Circular Cylinder Subjected to Axial Load on its Lateral Boundary
    35-42
    Views:
    148

    In this paper we consider the problem of single circular elastic inhomogeneity embedded within a circular cylinder whose curved boundary surface is subjected to surface traction acting on axial direction. We investigate the displacement neutrality of the coupled system of host body and inclusion. Neutral inhomogeneity (inclusion) does not disturb the displacement, strain and stress fields in the host body. The deformation of the considered inhomogenneous cylinder is antiplane shear deformation.

  • Development of Analysis of Loss Sources of Vehicles
    733-737
    Views:
    199

    Vehicle fuel consumption can be significantly influenced by various types of losses such as loss from bearing, aerodynamic drag and rolling drag. It is important to highlight that fuel consumption reduction can be only achieved when those losses are reduced that are induced during the operation.

    The aim of our work group is to define the calculation method and the magnitude of the losses of the vehicles. These parameters are intended to be serve as input parameters for future energetic modelling of vehicles.

  • Utilisation and Quality Management of Power Plant Fly Ash
    329-337
    Views:
    216

    Over the past decades, both the residential and industrial energy demand has increased due to the continuously growing consumption and production. As a large share of the electricity is still produced using fossil fuels, the utilisation of the by-products is a contemporary and pervasive issue. Fly ash is generated in large quantities in coal-fired power plants and has been proven to be an appropriate raw material for various industrial uses. Among others, it is applicable as an additive and lightweight aggregate in the cement and concrete industry, can be used for CO2 sequestration, glass foam production, catalyst production, or as a base material for geopolymers, as well. Geopolymers are inorganic polymers produced via the reaction between solid alumina and silica containing or alkali silicate materials in alkali media. Due to their numerous advantageous properties and wide variety of utilisation possibilities, research on fly ash base geopolymers became widespread topic. The quality of fly ash is determined by technical requirements, and the degree of quality control requirements depends on the final use. In certain fields of applications, standards and regulations have already been created to ensure the consistent quality of the final products made from fly ash, e.g. in the cement and concrete industry. There are various methods for fly ash processing, however, the methods to achieve the necessary properties are not standardised.

  • Investigation of the Luxury Yachts Condition and Their Maintenance
    95-105
    Views:
    201

    Surveying the condition of yachts and their maintenance is of great importance for their functionality and efficiency. Finding the right approaches, expertise at different levels, design benchmarking are essential for all yacht maintenance and security, resulting in crew and passenger safety. This report presents an evaluation and expertise in a real environment and documentation of decision-makers for the strength and functionality of a luxury motor yacht. For a good understanding of the problem, detailed photographic material has been documented showing in detail the required technical corrections. The research would be of interest to a wide range of yacht design and industry professionals, academic and research representatives, yacht users and all interested stakeholders.

  • Why do not people attend football matches in Hungary?
    11-22
    Views:
    299

    Both international and domestic research on passive sport consumption focuses on the motivations of fans. However in Hungary, unlike the examples of North America and Western Europe, we have to look for answers to the question of why people do not go to football matches. In order to find an answer to this question, we conducted an online survey with a number of items of 347 people. For the latter a scale measuring absence from sport consumption was used and the reliability of the scales was tested by Cronbach's alpha calculation. After our principal component analysis, we developed 5 internal and 5 external factors, on which we conduct hypothesis test along demographic and sports consumption variables. Based on our results, we have established that, contrary to public opinion, the low number of spectators in Hungarian football matches is not only and primarily due to unsucces and the low quality of matches. Our respondents are mostly kept away from stadiums by football-related government measures, as well as by preferring to participate in other recreational program opportunities.

  • Rotational molding of plasma treated polyethylene/short glass fiber composites
    103-108
    Views:
    176

    Rotational molding is a manufacturing technique for producing 3D hollow parts by adding plastic powder to a shell-like mold and rotating the mold while heating it with the powder. In contrary to the injection molding all the process operates at atmospheric pressure which makes reinforcement of the rotomolded product difficult. In this paper plasma treated PE and short glass fibers were dry mixed and used to produce composites by rotational molding process and characterized in terms of morphology and mechanical properties.

  • Perceived Barriers to Youth Entrepreneurship in Pakistan and Hungary
    382-391
    Views:
    137

    Entrepreneurship brings enormous benefits. It generates employment and helps in social and economic development. Ventures created through the youth entrepreneurship have enormous benefits. They generate employment, reduce poverty and unequitable distribution of wealth. These ventures do also help in social, economic and technological development. However, the youth faces several barriers to entrepreneurship. This study explores the personal & psychological, family related, institutional & regulatory, cultural & social, financial and market & knowledge barriers faced by the youth of Hungary and Pakistan. Qualitative research methodology was applied. Interviews at micro and meso levels were conducted from the young entrepreneurs and university professors of Pakistan and Hungary. Results indicate that Pakistan and Hungary have almost similar levels of Personal & Psychological barriers, however, the fear of failure is higher in Hungary than in Pakistan. Family related, cultural & social and market & knowledge barriers are higher in Pakistan for the youth entrepreneurship than Hungary. Institutional & regulatory and financial barriers are at medium levels in Pakistan. For Hungary, these are at low levels. The study has important implications for researchers, academicians, policy makers and for the young aspiring entrepreneurs.

  • Interchange of Heat in Saw Disc Body During Cutting
    488-494
    Views:
    125

    The paper presents the experimental results of a research aimed at the distribution of the temperature on the circular saw blade body. The temperature was measured at two distances from the centre of the circular saw blade body (70 mm, 140 mm) by means of an infrared thermometer. Two circular saw blades with the diameter of 350 mm and a variable adjustment of the body (with slots and without the coating, with both slots and coating) were used for the longitudinal sawing of the spruce wood (Picea excelsa) with the thickness of h = 37 mm. Feed speeds ware vf1 = 14 mpm, vf2 = 17 mpm and vf3 = 20 mpm. Cutting revolutions n = 4100 /min. were constant. The measured temperature was in the range from 21 °C till 27 °C. The highest measured temperatures were recorded on the circular saw blade with the slots and coating.

  • A Debreceni Egyetem Gazdaságtudományi Karának Controlling és teljesítménymenedzsment szakirány kurzusainak értékelése
    100-107
    Views:
    505

    It is of major importance for the Faculty of Economics and Business of the University of Debrecen to become familiar with the opinion of students about the education carried out at the University, therefore particular attention is given to the feedback of students related to education. Measurement and evaluation/reviews serve multiple purposes. Students may – if explicit written consent of the lecturer is provided – get to know the opinion of their fellow students about each course, lecturers may receive feedback about the reputation of their courses, the University and Faculties may acquire information about the overall opinion of their students about the training. Feedback is basically suitable for supporting the work aimed at the improvement of training quality. In the scope of present study the reviews submitted by the students of the Controlling and performance specialisation within the Management and Organisation course are introduced.

  • Review of Drive Systems Applied in Modern Vehicles
    728-732
    Views:
    198

    In this publication we review the drive systems of modern electric and hybrid vehicles. We also discuss the various types of electric motors, batteries, as well as fuel cell systems applied in them. Furthermore, as an important part of hybrid vehicles is the internal combustion engine, we review the literature about the methods used to.

  • Impact of Digitalization on Domestic Trade Strategies
    318-333
    Views:
    1455

    The aim of our study is to reveal the fit of digital space into current and future trade and to assess the effects of digitization on Hungarian trade strategies. The information gathering and purchasing habits of consumers have changed dramatically in recent years. Consumers today make buying decisions based primarily on convenience, effectiveness (fast and convenient access to products at adequate price/value ratio), and experience. Adjusting to these trends, traders developed novel trading strategies, and the use of achievements of digitization is an integral part of these strategies. One aspect of digitization is the increasing global development of e-commerce. The Hungarian online commerce have also been expanding significantly from year after year: based on 2018 data, domestic and foreign online sales volume have passed 1000 billion HUF. The Hungarian online consumers buy on the Internet more and more often and at greater and greater value. The online shopping on virtual reality platforms may make this purchase mode more experiential. Webshops have to meet new consumer needs, and deliver the ordered products as soon as possible, preferably within 24 hours. An increasing number of parcel delivery options has begun becoming more and more popular (e.g., automatic parcel terminals, pick pack points). However, traditional channels should not be buried, either. Their obvious advantage is that consumers can take their choice based on multiple senses and it also gives them more room for impulse buying. Combined with the digital technology compliant with contemporary requirements, this can offer a complete shopping experience. Nowadays, recognizing this need online and traditional channels have been mixed in several cases (e.g., multichannel, omnichannel, cross-channel sales) and offer several options for consumers during the purchase process. The sales area optimization of traditional shops and the buyer paths aided by digital technology (e.g., digital shelf labels) are designed for the buyers’ convenience. The newest innovations imply automation of the buying process making the whole process more convenient and more personalized with the use of sensors (e.g., Amazon Go) or robots (e.g., Pepper). In our future purchases, digital personal assistants will appear as digital versions of sales personnel.

  • Study on Nonlinear Behavior of Variable Thickness Plates
    72-80
    Views:
    66

    The analysis of variable-thickness plates is much more complicated than that of uniform-thickness plates because variable coefficients occur in the equations. In reality, this analysis is of great interest in various engineering disciplines, such as civil engineering, aerospace engineering, machine design, and so on. Although there is extensive literature on analyses of plates with constant thickness, a rather limited amount of technical literature is available on the solutions to problems dealing with plates with nonuniform thickness. The reason is that the analytical solutions meet insurmountable difficulties. Besides, the nonlinear analysis process also faces more difficulties than the linear analysis of structures. For these reasons, the nonlinear behavior of variable-thickness plates based on a finite element procedure is presented in this study. Although the topic is not special, it will help the engineer have a specific view of the nonlinear bending of the plate with variable thickness. This survey will be based on the change in geometrical parameters. Numerical solutions are then presented to verify the simplicity of this proposed procedure.

  • Construction Solutions for Reducing the Effect of the Rear-end Collision
    Views:
    156

    Analysing the accident statistics, we can detact that, the improvement of the transport safety is one of the most important engineering task. The number of the vehicles in the trasport gets significantly higher from year-to year, and the infrastructure of the cities frequently can not coordinate already it. Therefore the increasing of the vehicles’s number naturally involves the upgrowth of the accidents occasions too. The aim of the improvement of the vehicle-construction to reduce the personal injured and death resulted accidents number in contrast with the increasing traffic performance. This study analyses the construction options for reducing the effect of the rear-end collision whiches are concentrated for the passive vehicles and its passengers firtsly.  Among the actual car manufacturers applied solutions, foward-looking possibilities and suggestions are described in this publication. The development can not be concentrated for only the safety improvement, the mass-optimalization must be completed simultenously. These apparent contrary requirements can be completed with application of new materials. Therefore the study addresses the more optimal utilization of the meatl foam in the vehicles crushbox. In addition, an optimized break-assist solution is described based on the Mercedes developed Pre Safe Plus® system to increas the abrorbtion of the impact energy.

  • Evaluating the Efficiency of Polyhedral Mesh Elements in Solving the Problem of the Flow around Ship’s Rudder
    241-256
    Views:
    243

    Meshing is one of the crucial key features to the success of CFD based simulations, this study is evaluating the efficiency of polyhedral elements in solving the problem of the flow around ship rudder, using a Reynolds-averaged Navier-Stokes turbulence model (SST k-ω), and compares it to a tetrahedral based mesh, considering that polyhedral elements were neglected in the past due to difficulties in implementing them, this was solved by introducing a tool by ANSYS that converges tetrahedral elements to polyhedral element, and integrating it into FLUENT software, the model was validated by comparing it with previously validated model which used the full version of ANSYS, this study was concluded using the academic version, but still it was able to produce satisfying results in predicting the lift and the drag coefficient, the pressure around the rudder surface, the velocity and the turbulent kinetic energy, finally the mesh quality was evaluated using the orthogonal quality criteria, the results showed the supremacy of the polyhedral elements in saving time and computational resources and improving mesh quality, and keeping high level of accuracy in predicting the results.

  • Tribological Behaviour Comparison of ABS Polymer Manufactured Using Turning and 3D Printing
    46-57
    Views:
    197

    Additive and subtractive manufacturing of Acrylonitrile Butadiene Styrene (ABS) were employed for fabricating samples. The Additive manufacturing was represented through 3D printing, whereas subtractive manufacturing carried out by Turning. Some developments have been applied for enhancing the performance of the 3D printer. Tribological measurements of the turned and 3D printed specimens have been achieved. Studying the difference between static and dynamic friction factors and the examination of wear values were included. A comparison of the tribological behaviour of the turned and 3D printed ABS polymer has been investigated.

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