Keresés

Keresési eredmények

• Municipal Geothermal Systems: Evaluation of Three Hungarian Cases

  81-93

  Szolga Krisztián

  Árpád István W.

  Kocsis Dénes

  Megtekintések száma:

  62

  Geothermal energy holds great potential for a sustainable future, as it is a clean and weather-independent form of energy. In addition to energy production, it can also serve the population of a region through direct use. In this paper, three municipal geothermal systems (Szarvas, Nagyszénás, Békéscsaba) in the same Hungarian region which have been recently installed or expanded are presented and analysed. Here, the direct usage of geothermal energy for heating purposes is a very important issue. The three systems show several differences and to some extent face different challenges in the various phases of the projects. Particular attention has been paid to engineering solutions to the problems that arise. The challenges, such as technical difficulties during installation, maintenance difficulties, or problems arising during operation are introduced. The strengths, weaknesses, opportunities, and threats of similar geothermal systems were summarized, based on the relevant literature. These points were evaluated by their appearance and characteristics in the examined systems. This study aims to provide insights, based on recently gained experiences, into geothermal projects, thus providing feedback and practical information for researchers and practitioners.

• Analysis of Thermal Degradation in the Annealing Process of Colored Parts Built by Extrusion-Based 3D Printing

  124-133

  Castro Vera Kleber Leonardo

  Santana Leonardo

  Lino Alves Jorge

  Megtekintések száma:

  366

  With the ever-increasing request of light materials, poly lactic (acid) PLA, have got much in consideration. Low-cost PLA materials have risen its use. Those possess some benefits but nevertheless insufficient mechanical strength. The printed PLA objects have a stumbling block for practical applications. Thus, annealing is an interested alternative to make 3D printed objects strong. This thermal treatment can significantly develop investigational studies and offer technical data. Hence the purpose of this paper is study and discuss how to increase the flexural strength through annealing process. Geometry distortions and color degradation will be analyzed. Differential Scanning Calorimetry, Taguchi Method (TM) and variance (ANOVA) were applied as part of the design experiments and analysis. Twenty-seven printed specimens were tested and factors as temperature, time and color were selected.

• Maintenance of Electric and Hybrid Vehicles

  37-46

  De Souza Araujo Paulo Victor

  Komlósi István

  Varga Tamás Zoltán

  Menyhárt József

  Megtekintések száma:

  475

  An electric car is a vehicle powered by one or more electric engines, utilizing energy stored within batteries that are rechargeable. The first register of a usable electrical vehicle dates from 1880s. A hybrid vehicle incorporates two or more different power types, including, e.g., gasoline engines and electric motor. The goal in this work is to present the overall overview of the structure of the electric, hybrid and electric-hybrid vehicles, advantages and disadvantages of these types, the main points to focus when maintaining these and the challenges involved in its production and maintenance.

• Aktuális kihívások a közúti járművek CO2-kibocsátására vonatkozó szabályozások területén

  738-742

  Kocsis Dénes

  Bellér Gábor

  T. Kiss Judit

  Árpád István

  Megtekintések száma:

  181

  Napjainkban a klímaváltozással szemben folytatott küzdelem részeként az üvegházhatású gázok kibocsátásával kapcsolatos szabályozások egyre nagyobb teret nyernek. Munkánk során a közúti járművek szén-dioxid-kibocsátására vonatkozó európai uniós szabályozásra fókuszálunk, különös tekintettel a célértékek változására. Áttekintjük továbbá a CO2 emisszió mérésére vonatkozó mérési metódusok terén bekövetkező változásokat, mint a szabályozások egyik lényeges alappontjait.

• Sustainable Energy in Aviation with Reverse FMEA Analyses

  29-40

  Menyhárt József

  Al-Aghbari N. G. E.

  Megtekintések száma:

  67

  This research aims to identify and evaluate the key challenges and obstacles hindering the adoption of sustainable energy in the aviation industry. The outcomes and insights derived from this research will be synthesized to provide a comprehensive overview of the opportunities and suggestions for the adoption of sustainable energy in the aviation industry. The objective of this study is to help the aviation industry’s shift toward more sustainable energy sources in order to reduce its environmental footprint and mitigate the effects of climate change. 

• Solid-Lattice Stem Optimization Design for Hip Implants

  39-46

  Castro Vera Kleber Leonardo

  Al-Jweijati Mustafa

  Megtekintések száma:

  398

  The 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.

• Developing a Financial Sustainability Model of the Performance Indicators Applied by Jordan Water Company (Miyahuna)

  75-87

  Owais Lubna

  T. Kiss Judit

  Megtekintések száma:

  244

  Jordan is now facing real challenges to satisfy the current population water needs due to limited resources. Moreover, unfortunately, as a result of the increased demand for water in developing countries, water resources become scarce, thus, the sustainable management of water resources is very important everywhere and especially in these areas. The Ministry of Water and Irrigation in Jordan is aiming to improve both its quality of service and financial sustainability, therefore, it started to apply the performance measurement system developed by the International Water Association (IWA) to monitor its performance towards achieving these goals. In this article, a model connecting a financial sustainability indicator (operating cost coverage ratio) with other performance indicators applied by the ministry is developed. To assess the performance indicators and to build the model secondary data are collected from the targeted company, the data are analyzed using SPSS and Excel computer programs. Non-revenue water (NRW), speed of repair of bursts, and training per employee are found to be the indicators that have a major impact on Miyahuna’s financial sustainability, the NRW is found to have a negative relationship with the financial sustainability, whereas the other two indicators have a positive relationship. As a conclusion, reducing the NRW and increasing both the speed of repair and training per employee are recommended, by applying some methods that continuously diagnose problems in the water systems and defining clear and strict policies to control the water theft. Furthermore, using Active Leakage Control (ALC) methods, providing the needed equipment, tools and resources, and adopting new methods for training.

• LSI with Support Vector Machine for Text Categorization – a practical example with Python

  18-29

  Gomes Da Costa Cavalcanti Joao Henrique

  Menyhárt József

  Megtekintések száma:

  355

  Artificial intelligence is becoming a powerful tool of modernity science, there is even a science consensus about how our society is turning to a data-driven society. Machine learning is a branch of Artificial intelligence that has the ability to learn from data and understand its behavers. Python programming language aiming the challenges of this new era is becoming one of the most popular languages for general programming and scientific computing. Keeping all this new era circumstances in mind, this article has as a goal to show one example of how to use one supervised machine learning method, Support Vector Machine, and to predict movie’s genre according to its description using the programming language of the moment, python. Firstly, Omdb official API was used to gather data about movies, then tuned Support Vector Machine model for Latent semantic indexing capable of predicting movies genres according to its plot was coded. The performance of the model occurred to be satisfactory considering the small dataset used and the occurrence of movies with hybrid genres. Testing the model with larger dataset and using multi-label classification models were purposed to improve the model.

• Water Shortage in Jordan

  277-286

  Odeh Omar

  Megtekintések száma:

  398

  Water shortage in Jordan is considered to be one of the main challenges that face the country throughout the years. In this manuscript all aspects of this issue will be highlighted.  In this article, first, the water situation inputs, contests and outputs will be discussed. Secondly, there will be a detailed study about the ‘WADI AL-ARAB’ Project which is funded by the European Investment Bank and managed by the Yarmouk Water Company, its missions, assets and workflow. Finally, the Improvement of Energy Efficiency in the water sector, project aims, framework, and the major findings expected as a result of these analysis will be highlighted. This document presents the essential elements of a work that required a long time, an enormous effort and a hard work to collect all the data from several sources such as the Jordanian Ministry of Water and Irrigation (MWI), the Water Authority of Jordan (WAJ) and the European Commission (EU Official Website) and analyze them. Also, all the information listed about “WADI AL ARAB” Project was collected from multiple site visits.

• Six Sigma az előregyártásban: esettanulmány a betonacél megmunkálásnak fejlesztéséről

  49-60

  Pap Réka Zsófia

  Szűcs Edit

  Megtekintések száma:

  59

  A lean folyamatfejlesztések kulcsfontosságúak a termelési hatékonyság javítása érdekében. Kutatásunkban a DMAIC módszertan alkalmazásával vizsgálom az MEP üzem fejlesztését a lean six sigma jegyében. Kiemelve az előregyártott vasbeton gyártás kihívásait, a tanulmányom részletezi, hogyan segít a lean menedzsment a folyamatok hatékony tervezésében és méréseiben. A lean six sigma módszertan bevezetése folyamatok standardizálásával és hatékony fejlesztésével járul hozzá az üzem hatékonyságához.

• Building Information Modelling: Present realities and Future possibilities

  377-394

  Pogorelskiy Sergey

  Alava Diego

  Megtekintések száma:

  122

  BIM (Building Information Modelling), a term that is drawing the attention worldwide in the construction industry and governments, is a complex concept that involves management effort, tools and applications for enhancing information flow and therefore productivity for projects. This article pretends to briefly explain BIM, its advantages, challenges and potentialities while considering the current adoption of the concept in some countries. Furthermore, the article includes suggestions for the implementation of BIM in an organization as well as in projects and a list with some useful tools for this purpose.

• Innovation, Artificial Intelligence in Contingent Work-Force Management

  571-590

  Matonya Michael M.

  Megtekintések száma:

  608

  In recent years, the global use of contingent workers is rapidly increasing despite the increasing quantity of artificial intelligence applications in business. The question is "how these companies leverage the use of artificial intelligence to enhance contingent workforce's management?". The ideal goal of this paper is to develop a purely conceptual application of innovation, artificial intelligence (AI) adjacent to contingent workforce management(CWM). The researcher used qualitative information gathered from various authors and observations to reinforce the usage of AI. One of the critical tools to integrate with contingent workforce management for reduction of time spent on human resource administrative tasks is AI. There must be a transformation of thinking, accepting positive organizational change, utilization of technology and openness to new technology to foster  AI. Along with that, integrating contingent workforce management with AI reduces risks and costs, increases efficiency and quality of work. Innovation and Artificial intelligence have been used in five pillars performance of contingent workforce management to mitigate the challenges associated with it.

• Examination of the Relationship between Renewable Energy and Economic Performance

  234-243

  Boubou Hayyan

  T. Kiss Judit

  Megtekintések száma:

  189

  Many countries are making considerable efforts to achieve solutions to environmental problems that we face today and developing renewable energy resources is one of the potential long-term solutions that constitute an absolute priority from a sustainable development perspective. The usage of renewable energy is one of the critical future challenges to reduce greenhouse gas emission and decrease energy dependency at the same time. Thus, replacing traditional energy sources with renewable ones, like Hydropower and wind power to produce electricity instead of fossil fuel. The objective of this study is to find a relationship between renewable energy consumption, macroeconomic factors, and the environment. There is a reliable and significant (at 1% significant level) association between REC with GHG and GDP and a relatively strong association with EC.

• Micromechanical Model of Dry Friction Hybrid Polymer Composite Clutch Facings

  335-340

  Biczó Roland

  Kalácska Gábor

  Megtekintések száma:

  88

  Modelling the complex coupled thermomechanical and tribological contact of a dry friction clutch system between cast iron flywheel and scatter-wound hybrid composite clutch facing requires a thought through investigation of the friction material properties and behaviour. Challenges of the creation of a mechanical stiffness matrix for such a complex material are described in this paper along with simplification ideas and solutions.

• Trends and Challenges of Databases

  71-75

  Princz Mária

  Megtekintések száma:

  71

  The database management, using relational databases, is part of curriculum in the Hungarian high schools. The aim of this paper is to present how we can show for students the challenges facing data processing, data retrieval, beyond the relational database management taught in high school.

• Fémhabstruktúrák elemzése és geometriai modellezése

  145-152

  Varga Tamás Antal

  Mankovits Tamás

  Megtekintések száma:

  121

  A mérnöki kutatások egyik nagy kihívása a mára már széles körben alkalmazott fémhabok geometriai modellezése, valamint a megalkotott 3D-s modell numerikus szilárdságtani vizsgálata. A fémhab struktúrája meglehetősen bonyolult, így a valóságot jól megközelítő CAD modell előállítása önmagában is komoly mérnöki feladat, annak adott terhelésre történő végeselemes szimulációja pedig a kutatások középpontjában áll. A projekt ezen részének célja az előzőekben tárgyalt témakörökre vonatkozó nemzetközi szakirodalom kritikai elemzése és az eredmények adaptálási lehetőségei, továbbá egy térfogatelemzési eljárás bemutatása a fémhab celláival kapcsolatban.

• Fémhabok képi elemzése és geometriai modellezése

  89-92

  Varga Tamás Antal

  Mankovits Tamás

  Megtekintések száma:

  101

  A mérnöki kutatások egyik nagy kihívása a mára már széles körben alkalmazott fémhabok geometriai
  modellezése, valamint a megalkotott 3D-s modell numerikus szilárdságtani vizsgálata. A fémhab struktúrája
  meglehetősen bonyolult, így a valóságot jól megközelítő CAD modell előállítása önmagában is komoly mérnöki
  feladat, annak adott terhelésre történő végeselemes szimulációja pedig a kutatások középpontjában áll. A projekt
  ezen részének célja az előzőekben tárgyalt témakörökre vonatkozó nemzetközi szakirodalom kritikai elemzése és az
  eredmények adaptálási lehetőségei, továbbá egy térfogatelemzési eljárás bemutatása a fémhab celláival
  kapcsolatban.