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Found 6407 publications

The atypical approach to the development process of tertiary education

Enikő Baróti Attila Mészáros Attila

Publication Name: Advances in Intelligent Systems and Computing

Publication Date: 2017-01-01

Volume: 498

Issue: Unknown

Page Range: 1199-1208

Description:

The environment of the 21st century adult and tertiary education has changed at several places. The obstacles of information flow have disappeared and the educational environment has been virtualized. At the same time, the learning habits of students have also changed radically. These changes should be followed by tertiary and adult education as well. By accepting these phenomena workers of tertiary and adult education have to face a lot of fresh challenges. It is very important for them to adjust to the trends mentioned above Even those people who are not certified teachers need information, pedagogical and psychological knowledge to be able to find their way in the pedagogy of adult and tertiary education.

Open Access: Yes

DOI: 10.1007/978-3-319-42070-7_108

Comparative study of metaheuristics on optimal design of gravity retaining wall

Edina Koch Shaymaa Alsamia Hanaa Shihab Hamadi

Publication Name: Pollack Periodica

Publication Date: 2023-07-11

Volume: 18

Issue: 2

Page Range: 35-40

Description:

Retaining walls are typical geotechnical engineering applications analyzed extensively in the literature. However, the optimal design of these walls is still unsolved due to the optimization problem's complexity and the unrecognized best solver that can be used. Most similar works present a single optimizer for this problem. This work used six metaheuristics to formulate and solve the optimal gravity retaining wall problem design. The comparative study was achieved among particle swarm optimization, grey wolf optimizer, artificial bee colony, dynamic differential annealed optimization, fertilization optimization algorithm, and whale optimization algorithm. The problem and its results were discussed in detail within the respective sections.

Open Access: Yes

DOI: 10.1556/606.2023.00826

Airflow Resistivity Measurements of Acoustic Poroelastic Materials and their Influencing Factors

Dániel Feszty Balázs Vehovszky Attila Schweighardt

Publication Name: Manufacturing Technology

Publication Date: 2025-01-01

Volume: 25

Issue: 5

Page Range: 678-688

Description:

In the automotive sector, poroelastic materials (PEMs) are used as trim elements to achieve the desired interior acoustics of a vehicle. This study examines the effect of manufacturing as well as measurement techniques on airflow resistivity. This property plays a key role in the acoustic behavior of PEMs. First, the importance of engineering acoustics and poroelastic materials in vehicle industry is reviewed, followed by the introduction of the most important properties and their measurement techniques. Next, the theory and the measurement techniques used to determine resistivity via direct method are detailed. Then the factors influencing the results and their quantified effects are presented. More than 10 influencing factors are identified and examined, from which the inhomogeneity, resulting from the production technology proved to be the most significant. The results obtained with direct and inverse methods are compared for validation purposes and to determine the achievable accuracy of the inverse method. The average difference between the two methods is 4.54%, which means that the inverse method can provide a good approximation. Finally, conclusions are drawn and suggestions are made for the future.

Open Access: Yes

DOI: 10.21062/mft.2025.075

Production and Testing of 3D Printed PLA Structures with DIC Technology for the Reinforcement of Concrete Elements

Szabolcs Fischer Szabolcs Szalai Brigitta Fruzsina Szívós Hanna Csótár

Publication Name: Lecture Notes in Networks and Systems

Publication Date: 2025-01-01

Volume: 1258 LNNS

Issue: Unknown

Page Range: 175-187

Description:

3D printing technologies are now extensively utilized across numerous industries and scientific fields due to their ability to facilitate the practical testing of various design concepts cost-effectively and sustainably. This research focuses on PLA-based materials, known for their ease of recyclability. FDM printing technology was employed to identify the optimal printing layout for 3D-printed reinforcement elements in concrete, as this is not a standard parameter. Various material compositions and layout structures were analyzed using multiple printing strategies to find the most effective combination for innovatively enhancing the stiffness and strength of concrete structures. The GOM Aramis 5M DIC system, coupled with FDM printing technology, was used in this investigation, marking a novel approach in civil engineering.

Open Access: Yes

DOI: 10.1007/978-3-031-81799-1_17

Finite element modelling and indirect tensile strength of SBS and CR modified asphalt mixtures

Richárd Nagy Mohammad Fahad

Publication Name: Discover Applied Sciences

Publication Date: 2025-01-01

Volume: 7

Issue: 1

Page Range: Unknown

Description:

Different modifications in asphalt mixtures can be employed to improve the performance of asphalt pavements in terms of rutting and fatigue damage resistance enhancement. Performance of asphalt mixtures can be further enhanced with the use of different proportions of modifiers added to bitumen, however the optimum proportion of the modifiers added require further experimentation in terms of indirect tensile strength of asphalt mixtures. This research consists of selection of different proportions of Polymer (SBS—Styrene Butadiene Styrene) and CR (Crumb Rubber) modifiers, that have been used in various amounts at 7% CR, 15% CR, 20% CR, 4% SBS, 7% SBS to base bitumen and the performance has been compared with base asphalt mixture. Indirect tensile strength for each mixtures type has been evaluated in the lab with varying rise time. Furthermore, stiffness moduli of each mixture have been evaluated at four different frequency values of 1.2 Hz, 1.9 Hz, 3.5 Hz and 5 Hz at 20 °C. Moreover, tensile strength for each mixture type and its progression with varying loading rates from 10 MPa/s to 70 MPa/s has been evaluated. A 2D finite element software, ABAQUS has been used to perform microstrain analysis for each mixture type. Fatigue and rutting damage models have been used to evaluate performance of each mixture type. Results show superior performance of SBS-7 and CR-20 mixtures in terms of rutting and fatigue damage resistance when compared to base asphalt. SBS-7 and CR-20 show 28% better performance in terms of fatigue damage resistance when compared to base asphalt. SBS-7 outperforms CR-20 in terms of rutting resistance by 22%.

Open Access: Yes

DOI: 10.1007/s42452-025-06463-x

Investigation of the Track Gauge in Curved Sections, Considering Hungarian Railway Lines

Szabolcs Fischer Henriett Horváth Dalma Németh

Publication Name: Infrastructures

Publication Date: 2023-04-01

Volume: 8

Issue: 4

Page Range: Unknown

Description:

In this paper, the authors examined the change in track gauges in curves for several railway lines with low and high traffic in Hungary (i.e., secondary lines and main lines). They covered the processing of raw data as well as statistical calculations. The considered curved sections were transition curves (TCs) and circular curves (CCs), as well as—in some cases—entire curves (ECs), including TCs and CCs, but not dividing them into parts. The change of track gauge parameter as a function of elapsed time was analyzed based on the distribution functions by calculating the Vaszary-type shape number. A statistical test with the Kolmogorov–Smirnov test was performed, in which the question as to whether the measurement data of the railway lines followed a normal or lognormal distribution was examined; additionally, the skewness and kurtosis parameters were calculated and analyzed. The authors also took into account the impact of the track system and the sleepers. For the selected curves, the authors observed how the average track gauge changes and categorized them according to tolerances. In presenting and summarizing the tests, the authors formulated a conclusion for each study fulfilled. Despite higher traffic loads, the value of track degradation over time is lower for mainline curves than for secondary line curves. It is because the main line has stricter tolerances due to the higher speeds allowed, and more maintenance work is carried out on these lines. The authors concluded that the type of the track system and the sleeper type also influence the change in track gauges in curves. The accurate deterioration ratios for all analyses are contained in the paper.

Open Access: Yes

DOI: 10.3390/infrastructures8040069

Functional and environmental impacts of the use of reclaimed asphalt pavement materials and of foamed asphalt

A. Saleh László Gáspár

Publication Name: Acta Technica Jaurinensis

Publication Date: 2021-05-26

Volume: 14

Issue: 2

Page Range: 212-227

Description:

Environmental safety related to asphalt mixing plants has been a growing concern due to the high temperature of asphalt mixture production resulting in a lot of energy used and much air pollutants released. Asphalt mixtures with foamed bitumen and RAP can reduce this problem. This paper deals with their functional and environmental effects. In the paper, it was introduced that the hot mix asphalt mixtures bound by foamed bitumen and containing RAP materials provides a good workability, in comparison to “traditional” hot mix asphalt mixtures. However, producing foamed bitumen needs special technological steps before using it as asphalt binder. The use of RAP materials reduces environmental harm and construction costs, besides it preserves the limited resources of stone, sand and gravel.

Open Access: Yes

DOI: 10.14513/actatechjaur.00590

Visibility studies at roundabouts entries

Csaba Koren Zsófia Magyari

Publication Name: Pollack Periodica

Publication Date: 2019-01-01

Volume: 14

Issue: 3

Page Range: 63-74

Description:

Most accidents in roundabouts occur at the entries, partly due to poor visibility. To analyse this problem a sample roundabout with some visibility obstacles was measured by laser scanner and data were put into a 3D model. The fields of view were studied from the viewpoint heights of car and truck drivers as well. To assess the results, three indicators were defined: the hidden sight distance, the hidden sight triangle area and the angle of hide. These indicators were measured in the point cloud model. Through these indicators the adequacy of visibility conditions can be assessed.

Open Access: Yes

DOI: 10.1556/606.2019.14.3.7

Green supply chain awareness in the hungarian automotive industry

Zoltan Szegedi Ilona Papp Monika Gabriel

Publication Name: Polish Journal of Management Studies

Publication Date: 2017-01-01

Volume: 16

Issue: 1

Page Range: 259-268

Description:

The integration of the disciplines of both the green operation and the complex supply chain (including purchasing, production and logistics) came into focus in the 1990s. In the literature review the focus of the researchers of this cross-sectional field was the automotive industry. It seems obvious that these closely-knit systems with high OEM dominance will offer more concrete results: it is difficult to resist when a given OEM starts to involve its first-, second- and third tier suppliers into its environmental schemes and processes. The Hungarian automotive sector can be characterized as somewhat one-sided: it consists of by few large international OEM’s (Audi, Mercedes-Benz, Opel, Suzuki, Raba), but by a large number of small-medium enterprises as 3rd (or even 4th!) tier suppliers. The aim of the paper was to find out whether companies acting as a member of more advanced chains show also better results in their “green” supply-chain-behavior. As a study description, in our empirical research, we have created a toolkit, and examined whether companies, which are using more sophisticated inter-organizational cooperation-tools, are more environmentally cautious, and if yes to what extent. As a result, discussion it can be stated that companies with a higher developed traditional Supply Chain have also a more developed green supply chain management system.

Open Access: Yes

DOI: 10.17512/pjms.2017.16.1.22