Keresés
Keresési eredmények
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Prediction of FLD using Abaqus and Gurson Model for Simple Flat Spacemen
32-44Megtekintések száma:82In the past century, in many industries, such as, metal forming industry, it has been important to predict ductile damage and fracture of metals under complex loadings. Regarding damage mechanics, one of the most classical models is the GTN, which was originated from Gurson and later enhanced by Tvergaard and Needleman. The inprovement was achieved by introducing an equivalent void volume fraction f and two more parameters called q1 and q2 into the yield function of Gurson’s model.
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Fogyatékos tanulók szabadidős preferencia- rendszerének elemzése egy kutatás tükrében
98-115Megtekintések száma:671A fogyatékos személyek és a megváltozott munkaképességűek számának növekedésével, valamint a fogyatékossággal élő személyek célcsoportját érintő kutatások az elmúlt évtizedekben vettek lendületet. A kutatások igen sokrétűek, melyek vizsgálják a fogyatékos személyek munkaerőpiaci helyzetét, szabadidő-fogyasztási szokásaikat vagy a sportolásukat támogató és gátló faktorait.
A kérdőíves kutatásunkban a 8-18 éves fogyatékos gyerekek szabadidős és sportfogyasztási szokásait ismertetjük és elemezzük (N=639). Az adatokat spss szoftverrel dolgoztuk fel, ahol alapstatisztikát és összefüggésvizsgálatot végeztünk. Az eredmények azt igazolják, hogy a fogyatékos gyerekek szabadidőeltöltésében is a passzív tevékenységek dominálnak (TV, zenehallgatás). A sportfogyasztás (aktív és passzív) a fiú válaszadók között jelent meg dominánsabban, a lányok preferenciarendszerében kevésbé jelent meg. A sportolás motivációjában az egészségmegőrzés állapotjavítás melleltt a szórakozás, társaság is megjelent.
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Solid-Lattice Stem Optimization Design for Hip Implants
39-46Megtekintések száma:398The goal of this study is analyzed and design a methodology to reduce stem mass, through topology and lattice optimization of a Ti-6Al-4V hip implant, meeting yield stress requirements. Four optimization cases were studied: Topology optimization (1), Lattice design 100% (2), Lattice design 50% (3), Lattice design 25% (4). Five load cases from a study were applied for each optimization cases: Combined (LC1), standing-up (LC2), standing (LC3), going up stairs (LC4), jogging (LC5). The optimized cases design reduced stem mass approximately by 30% (1), 5% (2) ,8% (3) and 2% (4), compared with the total stem hip Ti-6Al-4V implant.
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A tudás iparosítása a Miskolci Egyetemen
61-73Megtekintések száma:183A „tömegesedés” következtében átalakult az egyetemek élete. A képzés költségei növekedtek, az egyetemek nagy létszámú állományt irányítottak. A gazdálkodás elmozdult a vállalatszerű működés felé. Az egyetem vállalkozói egyetemmé vált, a tudomány tudástermeléssé alakult. A tudománypolitika kezdte kiszolgálni az iparvállalatok igényeit. A tudás iparosítása című cikk Miskolci Egyetem kutatásait, fejlesztéseit és innovációját mutatja be. Az egyetem hazai és nemzetközi projektekben vesz részt, a kutatások hasznát fejlesztésekre fordítja, részt vesz az alapkutatásban, az alkalmazott kutatásban és a kísérleti fejlesztésben egyaránt. Az innováció részeseként segítenek a műszaki fejlesztések bevezetésében, új termékek megalkotásában. Működésük tapasztalatai mindenki számára fontosak.
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Business Process Development with the Application of Simulation Technique
109-118Megtekintések száma:137The object of our work to increase production efficiency with the use of cost-efficient development tools at a Hungarian small enterprise. We apply data gathering techniques besides process modelling and diagnostic methods to reduce the total process time of the assembly process so as to induce cost reduction in the production. In this respect we investigate and rank root causes of wastes by cost-effective process development tools, like timebased FMEA (failure mode and effects analysis) as well as the 5 whys method. With the use of Monte-Carlo simulation companies can evaluate the change in the process, therefore, they can decide whether they want to carry out corrective measures or not. The accomplished changes can generate increasing competitive edge in the long run.
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Structural Analysis of Carbon Fiber-reinforced Thermoset Composite
36-46Megtekintések száma:181Materials are usually stronger in fibrous form than in bulk form. Composites are made from bonding two materials, where the reinforcement contributes with the outstanding natural properties and the matrix supports the fibers by transferring the loads between them, besides protecting the fiber from the environment hazards. Consequently, creating a strong composite that can be used in various applications and situations. In this academic work it is going to be analyzed how the composite made from carbon fiber and epoxy thermoset matrix behaves in specific situations, by making them in two different manufacturing methods. In addition, the analysis is going to be made in the laboratories of the university and then compared with computer analysis. So, the first phase of this academic work is being presented and highlighted below.
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Analysis of Conceptual Solutions of Universal Helical Geared Reducers
64-72Megtekintések száma:136Geared reducers are mechanisms designed to reduce the number of revolutions using geared elements and nowadays they present one of the most commonly used types of mechanical transmissions in mechanical engineering. Due to the different shapes of geared elements, there are different types of geared transmissions: helical, bevel, worm, special and combined transmissions. This paper analyses only helical geared transmissions, since there is a great extent of whole this matter. Helical transmissions are analysed only with external helical gearing, since internal geared pairs represent a special and very large group of gears. Within the external helical geared transmissions, only torque transmissions are analysed, while the transmissions of motion are not analysed and they represent another large group of transmissions. Only universal gear reducers with axial, or almost-axial, parallel shafts are considered (two-stage and three-stage transmissions). Although, single-stage gear reducer produced with parallel shafts are not considered by the paper in order to reduce the area of researching. Gear reducers are most commonly delivered to customer with electric motor, known as motor geared reducer, and they are studied here extensively. Gear reducer can be also delivered without motor, only with input shaft. The basic aim of this paper is to present all characteristics and specificities of motor geared reducer in one place.
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Sportokkal foglalkozó civil szervezetek jellegzetességei, különös tekintettel a foglalkoztatásra
701-711Megtekintések száma:414A cikk célja a Magyarországon és Romániában működő civil szervezetek sajátosságainak összehasonlítása, különös tekintettel a sportokkal foglalkozó civil szervezetek foglalkoztatásban betöltött szerepére. Vizsgálatunkban megállapítottuk, hogy a két ország civil szervezeti szektora számos hasonlóságot mutat, ezek között pedig azt is meg kell említeni, hogy hasonlóan jelentős a lemaradása a nyugat-európai civil szférától. A civil szervezetek foglalkoztatási jellegzetességére jellemző, hogy körükben kifejezetten nagy az önkéntes munkavállalók szerepének jelentősége, azonban a fizetett munkavállalók jelenléte is megfigyelhető.
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A Literature Review: Artificial Intelligence Impact on the Recruitment Process
108-119Megtekintések száma:10839This paper aim is to review the implementation of artificial intelligence (AI) in the Human Resources Management (HRM) recruitment processes. A systematic review was adopted in which academic papers, magazine articles as well as high rated websites with related fields were checked. The findings of this study should contribute to the general understanding of the impact of AI on the HRM recruitment process. It was impossible to track and cover all topics related to the subject. However, the research methodology used seems to be reasonable and acceptable as it covers a good number of articles which are related to the core subject area. The results and findings were almost clear that using AI is advantages in the area of recruitment as technology can serve best in this area. Moreover, time, efforts, and boring daily tasks are transformed to be computerized which makes a good space for humans to focus on more important subjects related to boosting performance and development. Acquiring automation and cognitive insights as well as cognitive engagement in the recruitment process would make it possible for systems to work similarly to the human brain in terms of data analysis and the ability to build an effective systematic engagement to process the data in an unbiased, efficient and fast way.
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Production of Liquid Hydrocarbons from Plastic Wastes
345-350Megtekintések száma:119Thermal pyrolysis of HDPE, LDPE, PP and PS plastic wastes were performed in a batch reactor and the yields of pyrolysis oils and liquid transportation fuels prepared by atmospheric distillation were determined. The gasoline fractions were tested in a traditional spark-ignition engine without any modifications or fuel blending. Fuel consumption and exhaust gas emission (NOx, CO) were measured and compared to a commercial fuel (RON = 95). PS generated 70.5% gasoline range hydrocarbons from the solid waste, followed by PP with 42.1%, LDPE with 40.8% and HDPE with 37.3%. The fuel consumption was reduced by 9.1-9.4% in the case of PS compared to reference measurement. Reduction in fuel consumption was noticeable at HDPE, LDPE and PP as well. PS gasoline decreased by 91-96%, while HDPE, LDPE and PP more likely increased the CO emission of the engine compared to commercial gasoline. The results show that pyrolysis of plastic wastes is a promising method to generate value added liquid transportation fuels and reduce the footprint of waste accumulation in landfills.
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Tools to Develop End-User Programming Skills from Primary School to Higher Education
30-40Megtekintések száma:113Some years ago at the MIDK2013 Conference [16] we presented a concept regarding the use of a new generation of computer programming novice languages (in fact, an environment, called ‘block languages’). We showed how we imagine the use of this kind of language for different ages and at different levels of education. Now we would like to present the results of our projects related to this concept and our psychological and pedagogical experiences. Furthermore we would like to present further tools to develop end-user programming skills from primary school to higher education.
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Debreceni csoportos órát tartó fitnesz termek szolgáltatás kínálatának felmérése
35-48Megtekintések száma:292A fitnesz szektor gazdasági és társadalmi jelentősége folyamatosan növekszik. A fitnesztermek által nyújtott szolgáltatások skálája egyre bővül és ezzel együtt a fitneszklubok népszerűsége is gyorsan nő a lakosság körében. A fitnesz szolgáltatók által kínált edzések bárki számára igénybe vehetők, könnyen elérhetőek, számtalan típusú, méretű fitneszközpont áll a sportolni vágyók rendelkezésére, amelyet azért is szükséges kihangsúlyozni, mert a mindennapos testmozgás fontos színterei lehetnek ezek a sportlétesítmények. Azt, hogy mi alapján választanak a fitnesz fogyasztók edzőtermet, számos tényező befolyásolhatja, kiemelt szerepet játszanak ebből a szempontból a szektorban dolgozó fitnesz szakemberek. Kutatásunk több részből tevődik össze, amelyben olyan debreceni fitnesz termeket elemeztünk, ahol csoportos óra is elérhető. Megvizsgáltuk alap és mellékszolgáltatásait, interjúkat készítettünk a termek edzőivel és gazdasági elemzést is végeztünk. Ebben a tanulmányban feltérképeztük a termek földrajzi elhelyezkedését a városon belül. Vizsgálatuk a fitnesztermek adottságait, a honlapon található információkat, közösségi oldalon való megjelenésüket. Eredményeink tizenegy debreceni fitneszteremről kapott információink alapján levont következtetéseinket tükrözik. Ezek szerint a fitneszklubok száma folyamatosan változik, évről évre zárnak be és nyitnak meg vagy alakulnák át a fitneszközpontok, amelyek mérete és a kínált szolgáltatások száma alapján széles skálán mozognak. Minden fitnesz terem biztosít a diákok számára kedvezményeket, egyes termek célcsoportjai kimondottan az egyetemi hallgatók. A bankkártyás fizetés minden teremben elérhető szolgáltatás, a SZÉP kártyát a termek nagy része elfogadja fizetőeszköznek. Az elmúlt években a TRX, alakformáló és spinning óratípusok voltak a legnépszerűbbek. A közösségi oldalon népszerűbb termek folyamatosan, napi rendszerességgel osztanak meg híreket, ajánlásokat. Annak ellenére, hogy a vizsgált termek próbálják követni az éppen aktuális trendet, mégis vannak elmaradások, minőségi és mennyiségi különbségek a termek szolgáltatásai között.
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A Debreceni Egyetem vezetés és szervezés mesterszakos hallgatóinak tanulási motivációra irányuló vizsgálata
69-79Megtekintések száma:120Tanulmányunk célja a felnőttkori tanulás témakörének bemutatása. Ennek érdekében először meghatározzuk a tanulás definícióit és fontosságát az ember életében. Ezt követően kitérünk a felnőtt korban történő tanulás történelmi hátterére és alakulására. Bemutatásra kerül a felnőttkori tanulás motivációja különböző motivációs elméletek függvényében. A tanulmány második felében egy kezdeti kutatás kerül bemutatásra, melynek középpontjában a felnőttkori tanulás motivációja áll. Kutatásunk alanyai fiatal felnőttek, akik a Debreceni Egyetem Gazdaságtudományi Karának vezetés és szervezés mesterszakán folytatják tanulmányaikat. Arra szeretnénk válaszokat kapni, hogy a különböző tényezők milyen mértékben motiválják a fiatal felnőtteket tanulmányaik során. Az eredményekkel képet szeretnénk adni mind az oktatók, mind a versenyszférában dolgozó humánpolitikai szakembereknek arról, hogy miképp jellemezhető a vizsgált hallgatók tanulási motivációja. A kutatást a későbbiekben nagyobb mintára is kívánjuk majd kibővíteni.
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Investigation on Double Oxide Film Initiated Pore Formation in Aluminum Casting Alloys
141-153Megtekintések száma:330The most common, and in fact, the most deleterious defects of aluminum casting alloys are the so-called double oxide films or bifilms, which have a central role in porosity formation, as they can easily unfurl and inflate into pores during the solidification of the alloys. Sr addition is generally used in the foundry industry for the modification of the eutectic Si phase of hypoeutectic Al-Si alloys. However, Sr microalloying usually leads to an increased pore formation tendency. As bifilms are preferred sites for pore formation, it should be expected that Sr additions have a significant effect on the number and/or the structure of double oxide films present in the melt. In this work, the relationship between Sr-concentration and the susceptibility to pore formation has been investigated through the evaluation of melt quality of melts which had different levels of Sr. The bifilm content of the melts was investigated by the analysis of K-mold specimens and X-ray computed tomography (CT) of reduced pressure test (RPT) samples. It was found that liquid alloys with a higher Sr concentration had a significantly greater tendency to pore formation, which can be explained by the presence of a larger number of bifilm defects in the liquid alloy.
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Ultrasonic Powder Atomization for Additive Manufacturing
69-75Megtekintések száma:158The following article presents a special case of metal powder production, ultrasonic metal atomization. In this case, ultrasound technology is based on the capillary wave phenomenon. We verify the suitability of the produced powders for 3D metal printing with various tests. In the case of prints with a metal powder bed fusion (PBF), the properties of the raw material of the powder are extremely important. The main results of the tests carried out in the article (SEM images, EDS composition analysis, sieve analysis) were described.
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Efficiency of the Machining Process of Circular Shapes by Electrical Discharge Technology
53-61Megtekintések száma:90Due 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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Investigating the Impact of Nature in Designing Cultural Environments for Children
244-256Megtekintések száma:184There is a tendency to communicate with nature in human beings as a set of emotional experiences. This study investigates the impact of organic architecture in creating cultural spaces for children. The concepts of nature, naturalist architecture and children educational psychology, from the perspective of scholars and researchers in this area are investigated. The children’s perception of nature and their feelings were assessed and one hundred forty respondents among the instructors of cultural centres in different regions of Tehran have answered the questionnaires. To investigate the hypotheses, Univariate T - test and F - test were applied. The results showed that the stimulation of the natural environment has a positive and meaningful effect on curiosity, participation, and fantasy in children, while they show their impressions of nature indirectly. Therefore, designing applicable spaces according to children’s physics, using appropriate colours and furniture as well as more environmentally-related spaces, can have positive effects on social participation, intuitive and verbal skills of the children.
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Adaptability of Powdered Activated Carbon Production from Ground Catering Waste Pyrolysis Coke
162-171Megtekintések száma:120Three mixture of catering waste was pyrolyzed at 650, 725 and 900 °C and the solid residue (coke) was examined for powdered activated carbon production. For this, the carbon content, iodine number, particle size distribution and scanning electron microscopic images were analysed. Based on the carbon content, these cokes are suitable for activated carbon production, which were 60-85 wt.% (depending on the base material and pyrolysis temperature). The studied cokes showed slightly porous structure with smooth surfaces. Because of this, the iodine number was mostly small (13-30). Based on the grinding experiments, 10 minutes of grinding was found to be optimal. After this grinding time, the reached iodine number of powdered activated carbon was 350-610.
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Surface Quality of Carbide Metal After Electrical Discharge Machining
31-38Megtekintések száma:103Recently, the requirements for machining shape-complex products made of hard-to-machine materials, including carbide, have been increasing significantly. However, their machining is rather problematic. Additionally, a high-quality standard of the machined surface is generally required, not only in terms of roughness but also in terms of the geometric accuracy of the machined surface. All this while maintaining a high level of economy in the machining process. However, meeting these demanding requirements in real technical practice is not always an easy task. Moreover, in combination with modern machining processes, only a limited number of production technologies can meet this requirement. Therefore, due to the high demands placed on today's modern production and the required high standard of the machined surface, progressive EDM technology is increasingly finding its application. And it is through this progressive technology that it is possible to achieve relatively good success in carbide machining. The aim of this paper was therefore to describe in detail the results of an experimental investigation aimed at identifying the quality of the machined surface achieved in terms of the roughness parameters of the machined surface in the electrical discharge machining of selected types of carbides using a wire tool electrode.
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The Impact of labor Turnover on The Service Quality of Hotels
98-105Megtekintések száma:363This study aimed to know the dimensions of labor turnover (low morale, poor employees training, payment, job satisfaction) and study the effect of these dimensions on the quality of service in hotels. The results of multiple regression show that there is an effect of dimensions labor turnover on quality of service. Correlation between labor turnover and tangibility was the strongest and there is a moderate relationship between labor turnover and each of responsibility, reliability, assurance, and empathy.
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Structural Investigation of Granular Composites by Modern Methods
179-185Megtekintések száma:141Structural investigations of polymer-based particulate composites were carried out using modern test methods. We had composite sheets with different compositions and different injection molding speeds. In the polypropylene matrix, three types of glass beads were mixed in three weight percentages. In our investigations, the granular composites were studied with a widely used examination equipment, scanning electron microscope (SEM) and industrial computer tomography (CT) as a modern diagnostic tools. The purpose of the study was to investigate the distribution and interfacial adhesion of glass beads.
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Present and Future of Industrial Robotisation
1-12Megtekintések száma:70The following paper analyzing the installation of industrial robotisation in sectors and regions, in addition carry out forcastings on historical data. In recent years, automation and the use of industrial robotics have increased exponentially in the manufacturing sector. Given that companies prioritize enhanced production efficiency, quality assurance, and safety, it is evident that substantial investment and implementation of automation continue to occur in manufacturing facilities worldwide. The number of industrial robots globally has been growing steadily since 2010. However, the rate of growth has slowed from 2020 onwards. The impact of the Covid-19 epidemic was still felt in 2020, but the deployment of industrial robots increased significantly in 2021. Global industrial robot deployment is projected to continue to grow in the coming years, although the rate of increase may vary between regions and countries. The analysis showed a number of differences between regions in the number and growth rate of industrial robot deployments. Asia and Australia are the largest markets for robots and the number of robots deployed is expected to continue to grow in the future. Europe is the second largest market and, although growing at a slower rate, industrial robot deployment is also increasing steadily. In the Americas, growth is slower than in other regions, but still increasing. Global growth trends suggest that there will be further growth in the coming years and that the deployment of industrial robots will become more widespread in different parts of the world.
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The Effect of Fluxes on the Melt Quality of AlSi7MgCu Alloy
372-380Megtekintések száma:192The presence of inclusions such as oxides, carbides or refractory particles can be harmful to the mechanical and surface characteristics of castings. Inclusion-rich metals result in lower fluidity and feeding capability during casting. Nowadays, solid fluxes are widely used in foundries in order to reduce the inclusion content of aluminium melts. In this study, the effect of four different fluxes on the melt quality was studied. First, the inclusion content of the flux-treated melt, and then the properties of the fluxes (i.e. chemical composition and melting temperature) were examined.
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Mixing Power Requirement Determination in Agitated Drum Using Dimensional Analysis
76-88Megtekintések száma:134The mixing of granular materials in an agitated drum can be characterized by the dimensionless power equation. The equation was created by dimensional analysis, for which the parameters affecting the mixing power requirement were collected based on the literature. The most important of these are the rotational speed, the drum loading factor, the geometric and physical properties of the mixing drum and the granular materials. The dimensionless power equation is used to estimate with reasonable accuracy the Power number within the given range of applicability , which has been validated by measurements. From the Power number, the mixing power requirement of the mixed granular material can be calculated, which can be used as operational data for selecting the mixing motor.
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The Mechanical Properties of 3D Printed CuZn28 Brass Specimens with Different Orientations
253-259Megtekintések száma:217In this paper, the properties of CuZn28 brass raw material were presented. The 3D printed metal specimens are made from this material with different orientations. Their mechanical properties (tensile strength, yield strength) and elongation were investigated according to MSZ EN 6892-1: 2012 standard. The strength of the different printing directions is analyzed and it is determined which printing direction is the most favourable. Finally, the effect of the different printing directions upon the structure of the material is studied.
