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Interchange of Heat in Saw Disc Body During Cutting
488-494Views:107The 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.
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A Debreceni Egyetem Gazdaságtudományi Karának Controlling és teljesítménymenedzsment szakirány kurzusainak értékelése
100-107Views:480It 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.
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Review of Drive Systems Applied in Modern Vehicles
728-732Views:154In 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.
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Impact of Digitalization on Domestic Trade Strategies
318-333Views:1374The 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.
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Introduction to Design and Analysis of Torsional Vibration Dampers in Vehicle Industry
310-324Views:305The crankshaft of today’s internal combustion engines with high performance output are exposed to harmful torsional oscillations originated from the unbalanced gas and inertial forces. To avoid the fatigue damage of engine components, caused by the undesired vibrations, torsional vibration dampers can be applied. Viscodampers are one type of the torsional vibration dampers, which operational fluid is silicone oil. For cost-effective R&D activities and production, finite element and finite volume numerical discretization methods based calculation techniques must be involved into the engineering work supported by the modern computer technology. The aim of this paper is to provide an insight into the multidisciplinary design and development process of visco-dampers in vehicle industry applications. Four different examples as structural, fatigue, CFD analyses and structural optimization have been introduced in the present work. It turned out from the static structural and fatigue analyses, that the investigated damper has safety factor over the limit for both static structural and fatigue analyses, so it is suitable for the given load conditions. In the structural optimization process 34.36% mass reduction has been achieved. According to the coupled fluid dynamic and heat transfer simulations a rather stagnating air zone evolved between the engine and the damper during the operation, which can cause efficiency reduction of cooling fins mounted onto the housing. In light of the numerical results, the suitable damper position has been determined for the highest heat transfer.
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HAZ Characterization of Automotive DP Steels by Physical Simulation
478-487Views:158DP steels were extensively used in the vehicles industry due to its extraordinary combined properties of strength, ductility, formability and weldability which contributed great significance in reducing strength to weight ratio and CO2 emission. High strength steel i.e. DP steels (3 different grades) were experimentally investigated and thermophysically simulated using Gleeble 3500 simulator to determine softening and hardening in heat affected zone. Samples were heated to different peak temperatures (1350 °C, 950 °C, 775 °C and 650 °C), two cooling time (t8.5/5 = 5 s and 30 s) and Rykalin 2D model were selected. The hardness and microstructure of the specimens were tested and analysed. For longer cooling time (t8.5/5= 30 s), we observed that softening occurs in all grade of investigated DP steels to all sub-regions. But for shorter cooling time i.e. t8.5/5= 5 s the softening is higher in intercritical HAZ compared to other sub-regions for all the types of DP steel with short cooling time (t8.5/5 = 5 s). However, the hardening zone in the CGHAZ occurs when Tmax is 1350 ºC for DP600, DP800 & DP1000 steels but it is more prominent in DP800 as compared to others two steel grade.
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Polylactic Acid as a Potential Alternatives of Traditional Plastic Packagings in Food Industry
123-129Views:330Huge quantity of synthetic polymers is used as packaging materials in different fields of food industries. A significant part of these polymers applied as a primary, direct food contact construction. The scoped application area is the sweet industry. In this field Polystyrol (PS), Polypropylene (PP) and Polyethylene terephthalate (PET) have used but during the last fifteen years the usage of PET has been grown. In one hand the price of this material is efficient, form other hand the PET is the one of the most safe (for food industrial applications) petrol chemical plastic that can be used as primary or secondary food contact packaging material. To maximize the customer safety and minimize the environmental impact of traditional PET, a new bio-sourced and bio-degradable alternative polymer aimed to be used in this special food industrial segment. One of the potential alternatives is the Polylactic acid (PLA) that would be a possible substitute as it is compostable and produced from renewable sources and has good physical and mechanical properties [1].
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Evaluation Opportunities tor Recreational Sport Services – Adapted to Higher Education Environment
150-164Views:206In our study, we analyse various researches dealing with quality aspects of sport services, and different quality models related to the interpretation of quality. The results which were obtained in the framework of primary research activity present the opinions of students from five different research universities. Sport services’ operation and sustainability are determined by market regulations, as parts of the service industry. Considering that the university leisure sports services take place in a competitive environment, the universities often have to compete with external sports service providers for achieving confidence of the young generations. For the qualitative tests, we used the QSport-14 measurement scale, which is generally applied by sports centres. This scale investigates the sports services according to three different aspects: (1) instructors, (2) infrastructural facilities and equipment and (3) offered sport programs. We have adapted the measurement scale to the university environment because of the differences and special characteristics of external sports service providers and university sports services. In addition, we analysed the factors influencing recreational sports, and we also examined that what changes would be needed in order to improve the quality of recreational sport activities in higher education.
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Survey of the Dynamic Modeling Methods of Light Vehicles
723-727Views:198Vehicle dynamics models can be classified into two groups based on the model simplification. There are simplified models based on neglections, these models do not contain all body directions: longitudinal, lateral and vertical directions. There are several reasons for the simplification: control, estimation and analysis methods can be used only with simplified models, or another reason is the computational cost. Apart from simplified models, there are detailed/truth vehicle dynamics models which aim is to provide a virtual plant of the real vehicle for virtual prototype-based development. In this paper, some simplified vehicle models are presented, after a short introduction.
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The implementation of Balanced Scorecard System in social enterprises using the social-cooperatives – compliance with the needs of external organisations
300-317Views:218To discover the major economic problems of social cooperatives, we have made a survey. The analysis of this survey stated that the quality of available labour force and the finding of the proper target markets are the biggest concerns of social cooperatives. By this survey a Balanced Scorecard model (BSC) was implemented, which is an adaptation of Bull’s model (Bull, 2006). Present paper demonstrates the BSC modul to satisfy the needs of external partners and authorities. These needs and the tracing indicators were determined, furthermore the frequency of the indicator measurement was also proposed.
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Formation of Oxide Layers with Femtosecond Laser on Steel Surfaces for Color Marking
174-178Views:199With the appearance of ultrashort pulse lasers, the researchers have begun working on various laser marking technology. Atmospheric heating and ablation of a surface induce laser coloration of metal surfaces. However, their application is still problematic today in the industry. With the appearance of femtosecond pulse lasers, a new concept became available for color marking. This concept is based on the formation of laser-induced periodic surface structures (LIPSS) on metal surfaces. The purpose of this article is to summarize the literature of laser color marking with ultrashort pulse lasers.
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Improvement of High Strength Automotive Steels Wettability Properties Using CO2 Laser Surface Treatment
422-427Views:149As a result of stricter environmental and safety standards, vehicle manufacturers have to reduce the weight of the vehicles, because 10% weight loss cause 8-10% reduction of fuel consumption. To reduce car’s weight and increase safety, vehicle manufacturers use high-strength steels. Further weight reduction can be achieved by using corresponding bonding technology (soldering, sticking) and optimizing these technologies can increase the strength of the joints. According to literature research, the improvement of interface properties has a large effect on bonding technologies. In order to improve interface properties, we can use multiple surface treatments. In our research we investigate the effects of CO2 laser surface treatment on high strength steels, because CO2 lasers are often used in the vehicle industry. In order to detect the effect of surface treatment, we investigate the wettability of the treated and untreated steels. In our research we measure the surface tension of treated and untreated steels. Our main goal is to improve wettability properties thus the bonding technology. In our research we used DP 600 high strength steel sheet with the thickness of 1 mm. We cut the steel sheet to 25mm wide and 55mm long workpieces. Before the surface treatment, the workpieces had to be cleaned and degreased using methanol. We searched for parameters that do not cause any visible changes on the surfaces. Among the parameters of the treatment we were able to change the output power of the laser. We used contact angle measurement to examine the wettability.
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The Pressure Characteristics of the Released Gases from Sand Cores
73-79Views:138The core packages used for the production of castings are generally made from cores of different quality (no- bake phenol, HB-phenol, and HB-furan) and resin quantity, to meet the various requirements for the casting. In our research, the effect of the amount of resin on the pressure of the gases evolved from the cores was investigated. Experiments have shown that increasing the amount of resin has a different effect on different binder systems.
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Examination of Infrared Tomato Drying
303-309Views:82Tomato is a highly perishable food, thus preservation is required to meet the continuous market demand compared to the unbalanced yearly production peak. The aim of this paper is to show a detailed insight into infraradiation based drying process. Furthermore, to widen the possible usage range of a well-known approximation method for describing the temporal moisture variation in function of process parameters. The mass decrease of tomato slices was examined, in function of specific radiation power, heat source and sample distance, in forced and natural airflow. Based on the results dimensionless moisture ratio change over time was fitted as an exponential function, which may be used in industrial drying process optimization.
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Modeling the Thermal Behavior of Permanent Magnet Synchronous Motors
466-477Views:133The aim of this study is to present a thermal analysis of a permanent magnet synchronous machine based on finite element method. The developed model can be used to predict temperature distribution inside the studied motor during the rated operation. Electromagnetic computation is carried out with the aid of two 2D finite-element (FE) simulations on the cross-section of the PM motor. To analyse the process of heat transfer in an electrical machine, empirical correlations are used to describe the convective heat transfer from the different surfaces of the PM motor. The heat transfer coefficient is determined using dimensionless numbers and Nusselt number. After the loss calculation, the temperatures of the machine are calculated by using 3D finite element method. The results obtained by the model are compared with experimental results from testing the prototype electric motor.
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Analysis of Vibration During Turning Process of Different Materials
200-205Views:107In this article, we would like to introduce the problems caused by vibrations in case of polymer turning processes. Nowadays there is a lot of research in this topic, to avoid the unnecessary phenomena of vibrations. The two most common methods are the Spindle Speed Variation (SSV), and the Vibration Assisted Machining (VAM). In case of SSV, the CNC machine can increase and decrease the speed of spindle continuously during turning which can significantly reduce the effects of chatter. This method is beneficial for longer workpieces when there is not any support except the chuck. Vibration-assisted machining can be used to minimise the problems caused by vibrations. VAM combines precision machining with small-amplitude tool vibration to improve the fabrication process. It has been applied to some processes ranging from turning, drilling to grinding. Based on the enumerated above we made some trial measurements about the basic vibrations of the turning tool shank. The tests were done on an NCT EUROturn-12B CNC machine which can found in the workshop of our institute. The tested material was Polyamide 6 because this is the most commonly used polymer in the industry. In the future, we would like to test some other basic and composite polymer materials too. The equipment was served by a specialist from SPM Budapest Kft. With these tests, our goal was to make sure that the equipment and the measuring setup are suitable for our future research.
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What Fields Can Technology Management be Applied to?
637-645Views:168There are two types of technology management definitions. The narrow ones only refer to business organizations, the broad ones refer to any kind of organizations, including non-profit and governmental organizations. By using the narrow definitions, the interest of the non-profit and governmental organizations cannot be attracted, they could think that they do not need to deal with technology management, but in reality they obviously use it. To avoid the undue failing to utilize technology management knowledge outside the business world the broad definitions are recommended.
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The Propensity for Mandatory Audit Rotation and its Impact on Earnings Management in Europe
222-233Views:257The doubt of investors for the accuracy of financial reporting statements and the credibility of external audit functions has becoming more and more severe in the recent years due to a variety of booming accounting scandals related to earnings management occurring around the world. To cope with these serious frauds in the world of financial market, many countries have adopted Mandatory Audit Rotation (MAR) rules. Although the MAR rule has been valid around European Union (EU) members since 2016, the effectiveness of this rule has not been examined in any academic papers yet. As a result, the aim of this study is to investigate the effectiveness and the necessity of the latest MAR rule in the EU by testing the influence of audit rotation activities and audit tenure on earnings management of companies in the STOXX Europe 600 Index. Practical implications of this study will not also prove whether companies in STOXX Europe 600 Index should be required to shorten their audit tenure by rotating their audit engagement more often in order to decline the degree of earnings management, but they will also help to strengthen support for the essentiality of MAR legislations in the EU if the result indicates that longer audit tenure actually leads to more earnings management of STOXX Europe 600 Index companies.
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Role of Biomass in Urban Energy Management
62-76Views:127When making decisions on the use of energy, both on building and on city level, biomass plays certainly a role in looking for sustainable solutions. This study starts with highlighting some key points regarding urban energy management, including world urbanization trends, heat island effect of big cities and energy hierarchy in energy management. With these in mind, it is worth considering, how the shading effect of surrounding biomass can mitigate the heating needs as a wind barrier in the winter or decrease the cooling load as shadowing element in the summer, both for buildings and whole cities. These can be further enhanced by biomass integrated in the buildings’ envelope: green roofs and green walls can have significant energy conservation effects, according the characteristics of their different types. Lastly, urban disposal of biomass can lead to renewable energy generation, both in case of biogas production and waste incineration. These shading, covering and fuel possibilities all underline the importance of biomass in urban energy management.
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Vehicle Dynamic Simulation Possibilities Using AVL Cruise M
309-323Views:184In most cases, when creating vehicle dynamics simulations, we need software that can speed up model creation and simulation. There are many programs on the market for this purpose, but they have different knowledge and user interfaces. We present in this article briefly introduces the use of one of the market's leading vehicle simulation software, the AVL Cruise M.
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Increasing the Life of Mulching Tools
414-421Views:119Areas after mining or calamity are not amenable to immediate afforestation and require some adjustment. After removal of wood biomass, the rest of the residue is scattered throughout the area. To modify them, Several methods can be used to remove it. The optimal conditions for the planting environment and the subsequent adaptation process of the planting can be achieved by its mechanical, biological, chemical treatment. The basic prerequisite for a successful renewal of forests is their release from undesirable increases, in some cases from foams (trees) from mining waste. The area is also released when forest nurseries, seed plantations, etc. are established. The main purpose of the release of surfaces is to achieve the maximum throughput of the area for the machines to be moved. They wear during work. Wearing is a permanently undesirable change in the surface due to the interaction of functional surfaces or functional surface and wear medium. A tool that does not have any editing can go into a state where it can no longer be used anymore. An experiment was carried out in which 9 new teeth were placed on the rotor of the crusher and their wear patterns were observed. The article shows the progress of tool wear over time.
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Floorball position and passive sports consumption in the light of a study
142-157Views:205Research and studies done on floorbal is usually associated with medical studies, however the research and analisys of other fields peakd little interest.Thus, the aim of the study was to present the situation of floorball in Hungary and to examine the opinion of passive sports consumers about the sport. Within this we deal with the competition system of our country and the organizational structure of the federation. In our primary research, from a viewer perspective, we were interviewed as passive consumers in a questionnaire survey about their relationship to floorball. In the questionnaire we discussed whether they had ever met this sport and whether they had seen it or what attracted them to the match. We also tested their willingness to pay. The results were compared with the opinion of one of the domestic leaders of the sport, which in many cases agreed with the results. The questionnaire was completed by 153 people, more than 95% of whom had heard of the sport and most had the opportunity to become familiar with floorball at primary school. 65% of those surveyed have already seen a live floorball match that they have mostly played with friends / acquaintances. This young sport can become more and more popular among young people, not only as a complementary sport.
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Effects of TIG Reheating on Duplex Stainless Steel Weld Microstructure
295-302Views:133Duplex stainless steels (DSS) gaining their excellent mechanical properties and corrosion resistance due to their austenitic-ferritic microstructure, ideally in the same amount. However, to keep this ideal phase ratio during arc welding is very difficult. Generally, the arc welding processes will result in more ferritic microstructure in the weld metal and in the heat affected zone, due to the rapid cooling. The ferritic microstructure can cause chromiumnitride precipitation, because the nitrogen solubility in ferrite phase is very low below 700 °C. These chromiumnitride precipitations can cause loss of corrosion resistance and mechanical properties. However, during subsequent reheating, the chromium-nitrides can dissolve and act as a secondary austenite nucleation site in the ferritic microstructure. In our research we welded DSS specimen autogenously, with tungsten inert gas welding using pure argon and 94 % argon + 6 % nitrogen as shielding gasses. In the first case the sub-sequent solid-state reheating caused 20 % increase in the austenite fraction of the weld metal but with the use of mixed shielding gas only 5 % increase.
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Use Design or Technology: The Antique Römer Glass
33-37Views:107In this paper, the Römer-glass are assessed as indicator of the technology and design by using a comparative method. We identifed their designing technology methods and associated them with manufacturing centres. All of them made from green forest glass and produced in northwestern and central Europe from around 1000-1700 AD. The Römer glass present dining traditions and habits in the middle ages, furthermore like a personal belongings can be associated with the presentation of social status or individual expression.
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Entrepreneur Willingness in Case of Students of University of Debrecen
181-194Views:179This article is about the entrepeneur willingness in case of the students of University of Debrecen. There was 500 participants in the paper and online based survey who could tell their opinion about entrepreneurship in Hungary, what difficulties are they seeing and which part of the economy is where they see opportunity to start their own business. The aim of this article is to get to know how many of them and with what rate would like to start their own business, while it is examined they are from which faculty of the University, what is their family background and these facts how effects on the individual if his or her family owns some kind of business.
