Search Everything

Tip: Search using "First Name + Last Name", e.g.
János Kiss instead of Kiss János.

Publications - 6515

Optimal Elasto-Plastic Analysis of Reinforced Concrete Structures under Residual Plastic Deformation Limitations

Szabolcs Fischer Majid Movahedi Rad Sarah Khaleel Ibrahim

Publication Name: Acta Polytechnica Hungarica

Publication Date: 2023-01-01

Volume: 20

Issue: 1

Page Range: 45-62

Description:

In this study, an investigation regarding optimal elastic-plastic analysis method of different reinforced concrete (RC) structures is held by applying the residual plastic deformations limitations on the steel bars inside the reinforced concrete. Where different structures, including simple beam and slab, are selected as benchmarks and modelled numerically using ABAQUS in order to calibrate their experimental behaviour according to laboratory tests. Furthermore, concrete damage plasticity (CDP) constitutive model was applied to represent concrete behaviour in the numerical models considered. Then, an objective function was established for optimizing the applied plastic loads for each structure where the process of controlling plastic deformations was carried out by applying constraints on the complementary strain energy of the residual internal forces initiated inside the steel bars. This methodology was applied by authors by writing MATLAB code and linking it with ABAQUS to determine the corresponding applied plastic load for each entered complementary strain energy. Generally, applying optimization problem for each model showed that the complementary strain energy of the residual forces reflects the general behaviour of the structures and may be assumed as a constraint controlling the plastic behaviour of the structures whereas the obtained results indicated how structures acted differently when possessing different complementary strain energy values turning from elastic into elasto-plastic condition and then reaching plastic state.

Open Access: Yes

DOI: 10.12700/APH.20.1.2023.20.4

Digital data (protection) Security - A contestable and fair digital market ecosystem

Norbert Mozsonyi

Publication Name: ACM International Conference Proceeding Series

Publication Date: 2024-09-12

Volume: Unknown

Issue: Unknown

Page Range: 247-251

Description:

The topicality of the thesis is given by the new interoperability provisions of the recently enacted legislation on contestable and fair markets. In interpreting the role of interoperability, the study takes as a conceptual starting point the ability of different IT-based systems to work together, bearing in mind that in digital markets interoperability is a direct economic determinant of interoperability between platforms and third-party access. Gatekeepers as digital platforms have become a dominant phenomenon in our world, which may be extremely heterogeneous, but almost without exception they can be identified as having a number of interdependent technological, economic and social dimensions of coordination. It is true that the last few decades have seen the recurrence of legal issues relating to the management of data, but these are primarily constitutional approaches in the context of the individual's right to self-determination. Furthermore, it is a fact that enforcement and regulation have not kept pace with the development of extreme market concentration, nor with the achievement of transparency or accountability. The thesis takes a novel approach in several respects. On the one hand, it takes a power approach to the new world of digital sovereignty that has emerged in the last decade, and on the other hand, it uses the latest findings in systems theory and data science to present a specific approach that, in the current state of technological development, self-determination is no longer necessarily adequate to protect our data. We all have to come to grips with the idea that our data, traces of our behaviour, have become an asset that may be being processed and analysed by someone, somewhere. That does not make privacy 'dead' as many people think - it is simply that the focus may be on the rules for handling personal data rather than protecting it.

Open Access: Yes

DOI: 10.1145/3670243.3674223

The impact of irrigation with harvested rainwater containing asbestos cement matrix on the germination characteristics of Solanum lycopersicum

Gergely Zoltán Macher Dóra Beke

Publication Name: Acta Phytopathologica Et Entomologica Hungarica

Publication Date: 2024-09-06

Volume: 59

Issue: 1

Page Range: 63-73

Description:

The study aims to investigate how the transfer of matrix materials from eroded asbestos cement products induces stress responses in plants. The paper evaluates the exposure and risk factors of plants, water, and soil to asbestos cement materials. Additionally, the experimental results provide empirical evidence for plant stress responses based on physiological and germination parameters. Contamination of irrigation water with asbestos cement raises environmental concerns due to its potential toxicity to plants and soil quality. Asbestos in irrigation water can lead to toxic stress for plants, affecting germination processes and growth. The paper analyzes the effects of preset doses of irrigation water containing asbestos cement matrix on the germination process and physiological parameters of Solanum lycopersicum in a controlled experiment setting. This research proposes methodological developments that could be valuable for environmental plant protection professionals.

Open Access: Yes

DOI: 10.1556/038.2024.00207

GPS Based Navigation and Mobile Base Station of a Mobile Robot Platform

Rudolf Krecht Norbert Boros Dániel Eredits

Publication Name: Chemical Engineering Transactions

Publication Date: 2023-01-01

Volume: 107

Issue: Unknown

Page Range: 385-390

Description:

One of the central challenges of today is to increase the degree of automation of the available systems and equipment in a sustainable way. This paper presents the development of an outdoor mobile robot platform navigation method, including an on-board unit and a mobile base station to support the operation of the ZalaZone Automotive Proving Ground in Zalaegerszeg, Hungary, by precise, automated deployment of traffic cones. Currently, traffic cone handling is a time- and labor-intensive job. Its automation saves a significant amount of human resources. As a first step, the technical requirements of the problem have been defined. Then, the navigation system that met the pre-defined requirements has been implemented. This paper presents the detailed development of this navigation system, including a description of the test phases as well. As part of the development process, the operation of a Global Navigation Satellite System (GNSS) receiver corrected by Real-Time Kinematic (RTK) is presented, supported by a small, low-power mobile base station, followed by a description of the applied hardware and software components, alongside with the alignment and further development of these components to achieve centimeter-accurate positioning. The Network Transport of Radio Technical Commission for Maritime Services (RTCM) via Internet Protocol (NTRIP) server facilitates the communication between the onboard unit and the base station via a 5G network. This work is continued by a detailed description of the autopilot system on the robotic platform, including the tools and software used for this purpose. The calibration process of the navigation system is described as well. Finally, the results and observations gained during the test are summarized and analyzed. These results have shown that the addition of an RTK system has highly increased the accuracy of a general GNSS receiver. In addition, these results underline the crucial role of 5G networks in the case of automated mobile applications.

Open Access: Yes

DOI: 10.3303/CET23107065

Numerical Examination of a Forest Area Fire

László Környei Csaba Hajdu Flóra Hajdu Rajmund Kuti Dóra Beke

Publication Name: Chemical Engineering Transactions

Publication Date: 2023-01-01

Volume: 107

Issue: Unknown

Page Range: 61-66

Description:

An important task of sustainability is the protection of Earth's forests and the prevention of forest fires. In this paper, the numerical examination of a typical Hungarian ash forest fire is presented. The connection between sustainability and forest fire simulations is also discussed. For the simulation, a Fire Dynamics Simulator was selected, and a particle-based model was used. The simulation setup, which includes a random location of trees following Poisson distribution, is also explained. Then, the simulation of a 10x10 m area of ash forest is presented. It was found that in case of arson, the fire spreads rapidly among the trees, and there will be a high-intensity fire in which the forest area burns down in 4 min. The mass loss rate, the temperature, and the heat release rate also increased fast (above 50 kg/s, above 2,000 °C and above 800,000 kW). The aerosol concentration reached a high pollutant concentration (1.3x10-6), and the carbon dioxide concentration also increased significantly (above 14,000 ppm). These changes have a direct effect on climate change. Therefore, it is important to examine them in a simulation environment. The simulation was compared to a pine tree forest simulation, and it could be observed that in the case of the pine tree, the values are similar, but phenomena occur faster. With the computer simulation, it is easier to determine the areas affected by the fire, which also helps fire prevention and firefighting. The aim of the research is to contribute to the prevention and more efficient extinguishment of wildfires and the sustainability of the Earth.

Open Access: Yes

DOI: 10.3303/CET23107011

Transfer Learning-Based Steering Angle Prediction and Control with Fuzzy Signatures-Enhanced Fuzzy Systems for Autonomous Vehicles

Áron Ballagi Ahmet Mehmet Karadeniz Laszlo T. Koczy

Publication Name: Symmetry

Publication Date: 2024-09-01

Volume: 16

Issue: 9

Page Range: Unknown

Description:

This research introduces an innovative approach for End-to-End steering angle prediction and its control in electric power steering (EPS) systems. The methodology integrates transfer learning-based computer vision techniques for prediction and control with fuzzy signatures-enhanced fuzzy systems. Fuzzy signatures are unique multidimensional data structures that represent data symbolically. This enhancement enables the fuzzy systems to effectively manage the inherent imprecision and uncertainty in various driving scenarios. The ultimate goal of this work is to assess the efficiency and performance of this combined approach by highlighting the pivotal role of steering angle prediction and control in the field of autonomous driving systems. Specifically, within EPS systems, the control of the motor directly influences the vehicle’s path and maneuverability. A significant breakthrough of this study is the successful application of transfer learning-based computer vision techniques to extract respective visual data without the need for large datasets. This represents an advancement in reducing the extensive data collection and computational load typically required. The findings of this research reveal the potential of this approach within EPS systems, with an MSE score of 0.0386 against 0.0476, by outperforming the existing NVIDIA model. This result provides a 22.63% better Mean Squared Error (MSE) score than NVIDIA’s model. The proposed model also showed better performance compared with all other three references found in the literature. Furthermore, we identify potential areas for refinement, such as decreasing model loss and simplifying the complex decision model of fuzzy systems, which can represent the symmetry and asymmetry of human decision-making systems. This study, therefore, contributes significantly to the ongoing evolution of autonomous driving systems.

Open Access: Yes

DOI: 10.3390/sym16091180

Beta-Casein Genotyping in Dairy Cow Herds in Győr-Moson-Sopron County

Károly Tempfli Henrietta Buzás Sárvári Loretta Csilla Zsofia Meszaros László Gulyás

Publication Name: Chemical Engineering Transactions

Publication Date: 2023-01-01

Volume: 107

Issue: Unknown

Page Range: 451-456

Description:

The main objective of this study was to determine the beta-casein A1/A2 polymorphism status of animals in two Holstein Friesian dairy cow herds in Győr-Moson-Sopron County, Hungary. The A1/A2 status of cattle is determined by the beta-casein gene on the sixth chromosome. The analysed single nucleotide polymorphism is non-synonymous; A1 and A2 variants of bovine beta-casein differ at position 67 of the amino acid chain: A1 variant codes for histidine and A2 codes for proline, which may affect the milk protein degradation process. The analysed polymorphism leads to key conformational changes in the secondary protein structure of beta-casein. Beta-casomorphin (known as BCM7) is released only from A1-type milk and cannot be completely degraded by enzymes during digestion. DNA isolation was performed from whole blood, and a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method with agarose gel electrophoresis was applied in order to determine individual genotypes. The results from the two dairy farms demonstrate that a high proportion of cows (86.08 and 90.74 %) carry the A2 gene variant without targeted selection. At farm „A”, beta-casein polymorphisms were determined in 599 cows and 148 heifers. The genotype distribution of the cows was 47.25 % heterozygous, 38.83 % homozygous A2, whereas 14.02 % of the cows carried the A1A1 genotype. In heifers, A2A2 was already present in a remarkably high frequency (91.89 %), whereas the prevalence of heterozygotes was 7.43 %, and A1A1 animals made up only 0.67 % of the analysed heifer population. In Hungary, a growing number of dairy farms are using verified A2 homozygous breeding bull semen. The introduction of homozygous A2 sperm on the farm „A” remarkably increased A2 frequency in the heifer population. In total, 324 cows were genotyped on farm „B”, where the A2A2 genotype was observed in 30.55 % of the animals. The second most common genotype was A1A2, with a genotype frequency of 60.19 %, whereas A1A1 homozygotes occurred with a 9.26 % frequency. The growing popularity of A2 milk due to potential health benefits is driving Hungarian stakeholders towards the targeted selection of dairy populations; animal genotyping is an evident approach to facilitate this transition.

Open Access: Yes

DOI: 10.3303/CET23107076

Tribological investigation of the effect of nanosized CuO and TiO2 on a base oil containing Komad 323 dispersant

I. Szabó Márk Marsicki Hajnalka Hargitai

Publication Name: Jurnal Tribologi

Publication Date: 2024-09-01

Volume: 42

Issue: Unknown

Page Range: 103-128

Description:

This article investigates the impact of copper(II) oxide (CuO) and titanium dioxide (TiO2) nanoparticles in Group III base oil with 8 wt% Komad 323 dispersant. Nanoparticles underwent ethyl oleate surface modification. Tribological properties were assessed using a linear oscillating tribometer, continuously monitoring static friction. Friction integral values were derived from extensive data acquisition. Wear analysis employed digital optical and confocal microscopy, complemented by scanning electron microscopy for wear-type characterization and energy-dispersive X-ray spectroscopy for additive quantification in the wear track. Results indicate CuO nanoparticles' poor compatibility with Komad 323, resulting in increased friction (2-13%) and substantial wear reduction (39-50%) at low CuO concentrations (≤0.3 wt%). Higher concentrations (≥0.4 wt%) reduced friction (21-35%) but led to surface fatigue and increased wear rates. Elemental composition analysis of the wear track revealed that the surface contains 1.43-3.17 norm.wt% copper. Conversely, TiO2 in synergy with the dispersant, formed a boundary layer, exhibiting lower friction by 11-14%. TiO2 formed a high wear resistance boundary layer at titanium concentrations of 0.33-0.39 norm.wt%, which resulted in 44% wear volume reduction. Applying both nanoparticles reduced the wear scar diameter of the test specimens by 3-12%.

Open Access: Yes

DOI: DOI not available

Exploring Purchase Decisions in Virtual Reality: A Systematic Review and Future Research Directions

Boglárka Eisingerné Balassa Réka Koteczki

Publication Name: 2023 IEEE 2nd International Conference on Cognitive Aspects of Virtual Reality Cvr 2023

Publication Date: 2023-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

Virtual reality is becoming more widespread around the world and many industries are beginning to recognise its potential. In this paper, we have explored the relevant issues between virtual reality and marketing, based on which we have addressed the topic of virtual reality and retail. The methodology of the present paper is a Systematic Literature Review using the PRISMA model. Based on the SLR, 20 academic articles were found to be relevant to the research topic and are described in the paper. A further objective of the study was to design a future research plan, which was based on the SLR. Based on the research plan, future research will aim to investigate how the decision making process takes place in a 3D virtual shop and how it differs from 2D web shops.

Open Access: Yes

DOI: 10.1109/CVR58941.2023.10395641