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Publications - 6374

Numerical Modeling of Multi-Pass Arc Welding Processes: Integration with Experimental Validation for Distortion analysis and Characterization

János Szép Marco Domaneschi Majid Movahedi Rad Raffaele Cucuzza Daniel Gosztola Péter Grubits

Publication Name: Advances in Transdisciplinary Engineering

Publication Date: 2024-01-01

Volume: 59

Issue: Unknown

Page Range: 248-254

Description:

The increasing significance of numerical simulations in the welding industry arises from their capacity to improve manufacturing conditions, ensuring greater effectiveness and precision. The utilization of the finite element method (FEM) enables comprehensive and focused calculations of mechanical and material structural alterations induced by the welding process. Acquiring knowledge of these parameters not only serves to augment the quality of the manufacturing process but also yields consequential benefits, such as reducing adverse effects like base plate distortion. Consequently, enhancing structural performance and prolonging lifespan becomes achievable, aligning with overarching sustainability goals. To accomplish this objective, this paper involves the numerical simulation of a welding process based on experimental tests, with a focus on investigating the deformations caused by the heat generated during welding as the primary parameter of interest. Advanced modeling techniques are employed to assess the results as part of a comprehensive thermo-mechanical analysis framework, examining and characterizing the impact of the temperature distribution. In the finite element analysis (FEA), a total of 12 welding cycles were systematically modeled to align with experimental conditions, incorporating cooling intervals and preheating considerations. The outcomes of this research exemplify the potential of numerical simulation in the welding industry, demonstrating a diverse range of results achieved through FEA to enhance the quality of structures.

Open Access: Yes

DOI: 10.3233/ATDE240552

Workflow Development of AI Based Spectrogram Analysis with Real-time Out of Distribution Detection

Zoltán Weltsch Lóránt Szabó

Publication Name: Proceedings of the 2024 25th International Carpathian Control Conference Iccc 2024

Publication Date: 2024-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

The aim of this paper is to investigate possible workflows for OOD pattern recognition in AI-based spectrogram analysis, applied in industrial manufacturing environment. First, we attempt to identify and articulate the challenges associated with OOD recognition in the context of spectrogram analysis, where the acoustic sources are subtle and often complex signals. These deserve particular attention, since the effectivity of OOD detection algorithms are acceptable in case of significant deviations, however, it is questionable for fine anomalies. In addition, it is also discussed here, how OOD records can affect the accuracy and reliability of AI models in terms of equipment failure identification and process inefficiencies. Last, methodes are proposed for OOD-pattern recognition. The integrability of these methods into existing manufacturing workflows in terms of practicality, adaptability and effectiveness are also investigated.

Open Access: Yes

DOI: 10.1109/ICCC62069.2024.10569262

Possibilities of porous-structure representation – an overview

Balázs Vehovszky H. Szűcs

Publication Name: Acta Technica Jaurinensis

Publication Date: 2021-11-24

Volume: 14

Issue: 4

Page Range: 553-576

Description:

Porous media can be found in all areas of scientific life, such as medicine, civil engineering, material science, fluid dynamics. Computing has achieved high efficiency and computational capacity – so far. However, three-dimensional Computational Fluid Dynamics (CFD) simulations of microstructure remain significant challenges. Pore-scale simulations can help understand the physical processes and determine macroscopic parameters such as the high-frequency limit of dynamic tortuosity, viscous, and thermal characteristic lengths. Independent of whether the computational problem is two or three-dimensional, the geometry as input parameter must be prepared. For this reason, geometry representation methods play a crucial role in the analysis at the pore-scale, especially in numerical simulations. In this article, an insight into microstructures’ visualization capabilities is provided essentially for CFD simulations.

Open Access: Yes

DOI: 10.14513/actatechjaur.00591

Applying bacterial memetic algorithm for training feedforward and fuzzy flip-flop based neural networks

János Botzheim László Gál António E. Ruano Laszlo T. Koczy

Publication Name: 2009 International Fuzzy Systems Association World Congress and 2009 European Society for Fuzzy Logic and Technology Conference Ifsa Eusflat 2009 Proceedings

Publication Date: 2009-12-01

Volume: Unknown

Issue: Unknown

Page Range: 1833-1838

Description:

In our previous work we proposed some extensions of the Levenberg-Marquardt algorithm; the Bacterial Memetic Algorithm and the Bacterial Memetic Algorithm with Modified Operator Execution Order for fuzzy rule base extraction from input-output data. Furthermore, we have investigated fuzzy flip-flop based feedforward neural networks. In this paper we introduce the adaptation of the Bacterial Memetic Algorithm with Modified Operator Execution Order for training feedforward and fuzzy flipflop based neural networks. We found that training these types of neural networks with the adaptation of the method we had used to train fuzzy rule bases had advantages over the conventional earlier methods.

Open Access: Yes

DOI: DOI not available

Can multifarious types of green bonds be accused of greenwashing with a durative analysis? Insights from a permanent causality vs. temporary causality phenomenon

Laszlo Vasa Lubos Smutka Mohammad Nasr Isfahani Syed Ali Raza Mahdi Ghaemi Asl

Publication Name: Environment Development and Sustainability

Publication Date: 2025-09-01

Volume: 27

Issue: 9

Page Range: 21425-21449

Description:

Green bonds are useful monetary tools that can finance sustainable endeavors to bolster an eco-friendly economy. This research inspects the frequency-domain causal relationship between diverse green bond types and the green economy from June 30, 2014 to August 3, 2023. The goal is to understand both permanent and temporary causal phenomena between them. The findings reveal that only pioneering green bonds display a robust bidirectional causal link with an eco-efficient economy. Meanwhile, other green bond types, like conventional, municipal, and currency-dominated green bonds, may be susceptible to greenwashing due to the absence of a thorough permanent causal tie with an ecologically sustainable economy. Additionally, enhancing pioneering green bonds by integrating ESG (Environmental, Social, and Governance) stocks can transform the cause-and-effect dynamic between specific green bonds and the green economy. It shifts from a bilateral cause to a unilateral one stemming from the environmentally friendly economy and extending to distinguished green bonds. This phenomenon persists whether the 5% annual fee for sustaining and managing the index combining green bonds and ESG equities is considered or not. Interestingly, an environmentally conscious economy, in both persistent and transient associations, consistently affects ecological bonds with diverse traits. This highlights the importance of the overall state of an environmentally responsible economy in enhancing green bonds. These discoveries provide novel perspectives for green market regulators and policymakers to design improved standards for green assets.

Open Access: Yes

DOI: 10.1007/s10668-024-04501-z

Occurrence and distribution of polycyclic aromatic hydrocarbons in surface water and sediments of the Danube River and its tributaries, Hungary

István Vass Andrea Szabó Nagy János Szabó

Publication Name: Journal of Environmental Science and Health Part A Toxic Hazardous Substances and Environmental Engineering

Publication Date: 2014-08-24

Volume: 49

Issue: 10

Page Range: 1134-1141

Description:

Polycyclic aromatic hydrocarbons (PAHs) were identified and quantified in surface water and sediments from 9 sites in the Hungarian upper section of the Danube River and its tributaries in autumn 2012. The total PAH concentrations (sum of the concentrations of 17 individual PAH compounds) in water samples ranged from 67 to 96 ng L-1, which were predominated by two- and three-ring PAHs. The total PAH concentrations in sediments ranged from 35.2 to 288.3 ng g-1 dw. Four-ring PAHs including fluoranthene and pyrene were the dominant species in sediment samples. The spatial distribution of PAHs in sediments was site-specific. The highest benzo[a]pyrene equivalent concentration was determined at the site located near a hazardous waste incinerator. However, the comparison of the total PAH concentrations determined with other sections of the Danube River and the environmental quality standards revealed that the PAH concentrations are relatively low in the Hungarian upper section. A selected number of concentration ratios of specific PAH compounds reflected a pattern of pyrogenic input as a major source of PAHs. Copyright © Taylor & Francis Group, LLC.

Open Access: Yes

DOI: 10.1080/10934529.2014.897155

The Concept of BENIP – Built Environment Information Platform

Balázs Horváth János Szép Attila Borsos

Publication Name: Infocommunications Journal

Publication Date: 2023-01-01

Volume: 2023

Issue: Unknown

Page Range: 29-34

Description:

The built environment and its components require a continuous and uninterrupted flow of information between its various players. In this paper a conceptual framework is proposed describing the role of these players as well as the nature of the links between them. The authors introduce a new term, a conceptual framework which can be used as a platform called BENIP (Built ENvironment Information Platform).

Open Access: Yes

DOI: 10.36244/ICJ.2023.SI-IODCR.5

Structure Selection and LPV Model Identification of a Car Steering Dynamics⁎

Gábor Rödönyi Zoltán Szabó Péter Korös Dániel Pup Alexandros Soumelidis József Bokor

Publication Name: Unknown

Publication Date: 2018-01-01

Volume: 51

Issue: 15

Page Range: 1086-1091

Description:

A Linear Parameter-Varying (LPV), discrete-time black box model of an electric power assisted steering system of a passenger car is identified from open-loop step response measurement data. The goal is to provide a nominal model for control design and analysis that is able to describe the principal characteristics of the system in the whole region of steering angle and speed range of 3 to 30 km/h. Examining a set of experimental data by using classical linear time-invariant black box modeling and validation techniques, the structure of the LPV model is determined. The parameters of the model are identified based on minimizing a quadratic error criterion by nonlinear optimization algorithms.

Open Access: Yes

DOI: 10.1016/j.ifacol.2018.09.049

Calculation of Heating of Reinforced Concrete Tunnel Wall During Fire

Éva Lublóy Zoltán Major János Szép

Publication Name: Advances in Transdisciplinary Engineering

Publication Date: 2024-01-01

Volume: 59

Issue: Unknown

Page Range: 366-374

Description:

In this article, we present the thermal parameters of reinforced concrete tunnel lining materials and their changes during fire exposure. After describing the material properties, we present a test method to investigate the heating of reinforced concrete tunnel linings. As the presented method can only be considered as partially standard, we validate it on the basis of the available literature and our Excel program based on the presented theory. During the validation, it has been demonstrated that the method is suitable for solving practical professional tasks and that it is able to provide sufficiently accurate results. Since the results presented can be used not only for design purposes but also as an initial step in fire diagnostics to determine the extent of damage in fire-loaded tunnel walls, we also construct novel curves for the analysis of reinforced concrete walls, which can be used effectively for fire curves with cooling phase, where the accumulated temperature inside the wall further heats the zones inside and further residual strength loss may occur due to chemical processes in the zones. Based on the results of the model presented in this paper, designers can take into account the changes in the temperature distribution of the reinforced concrete tunnel wall, which have a decisive influence on the evolution of the internal forces due to external influences, and can calculate the magnitude of the stresses due to inhibited thermal expansion by using approximate models.

Open Access: Yes

DOI: 10.3233/ATDE240568