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Found 6674 publications

Numerical modelling of a solenoid optimization problem with a superposition-based model order reduction method

Tamas Orosz Kristóf Levente Kiss

Publication Name: Computers and Structures

Publication Date: 2025-09-01

Volume: 316

Issue: Unknown

Page Range: Unknown

Description:

This work investigates the application of a Model Order Reduction technique based on the Cauer ladder network method to the air cored solenoid geometry of the number 35 benchmark problem from the Testing electromagnetic analysis methods series, approaching both source and discrete radius optimization tasks. A projection-based reduced-order model was developed to accelerate the optimization process, achieving an average computational speedup factor of 35 compared to full-order finite element simulations. For discrete radius optimization, the problem was reformulated as a source optimization, enabling effective model order reduction application. The multiport Cauer ladder network approach reduced to a superposition of magnetic fields due to the simplicity of the problem. The reduced order model preserved consistency with the full order model when a small enough element size was chosen in the finite element model during its creation process. The error of the proposed methodology is an order of magnitude lower than the lowest objective function values in the optima, therefore it is suitable for multi-objective optimization.

Open Access: Yes

DOI: 10.1016/j.compstruc.2025.107906

Measurement of Pedestrian Targets in Terms of Radar Cross Section

David Jozsa Leticia Pekk Marton Jagicza Gabor Laszlo Toth Denes Fodor

Publication Name: Saci 2023 IEEE 17th International Symposium on Applied Computational Intelligence and Informatics Proceedings

Publication Date: 2023-01-01

Volume: Unknown

Issue: Unknown

Page Range: 363-368

Description:

In terms of vehicle radars, the most important properties of targets are speed, distance, and radar cross section. Based on the Radar Cross Section (RCS), the type of the object can be identified with a good approximation: pedestrian, bicycle, car, truck even in extreme weather conditions. A radar cross section measures the reflectivity of an object and its numerical value is equal to the area of the cross section of a conducting sphere with the same reflectivity. Its value depends on the material and shape of the object, the angle of illumination, and the ratio between the wavelength and the size of the object. The article presents a measurement system for radar targets, the main component of which is an automotive radar. In addition, the evaluation software for the measurement system, which was created in the MATLAB / SIMULINK environment, will be presented. The measurement system was used to perform various measurements on the ZalaZONE Automotive Proving Ground (Zalaegerszeg, HUNGARY), the evaluation of which will be presented. The purpose of the measurements is to collect information about the radar cross-section values of pedestrians at different distances from the vehicle and dummies simulating them. A comparison of different pedestrians is presented. After that, we will show how even if a puppet is formally similar to a pedestrian, the RCS can show a different value.

Open Access: Yes

DOI: 10.1109/SACI58269.2023.10158601

Residents’ attitudes and behaviours on private green spaces in the suburban areas of Central European countries

Hardi Tamás Ádám Páthy Andrea Pozsgai

Publication Name: Regional Sustainability

Publication Date: 2024-12-01

Volume: 5

Issue: 4

Page Range: Unknown

Description:

Green spaces in urban and suburban areas play a significant role in helping settlements adapt to climate change. The design, quantity, quality, and location of green spaces influence their ability to provide benefits to people and enhance the quality of life. Private green spaces, if adequately managed, can enhance the environmental quality. This study, based on a questionnaire survey and the Motivation/Attitude-Driven Behaviour (MADB) model, investigated how the attitudes and behaviours of residents shape private green spaces in 12 settlements of the 4 city regions (Cluj region, Nitra region, Kecskemét region, and Győr region) in 3 Central European countries (Hungary, Slovakia, and Romania). The results showed that beautiful natural environment, abundance of green spaces, beautiful settlement and streetscape, and village atmosphere were mentioned most often, along with good quality of life, with a mention rate of over 70.00% in the four city regions. Convenience also played a significant role in the management of green spaces, showing that convenience factors (less work, less waste, and cheaper management) more important for those who live in settlements nearer to the cities. The importance of biodiversity and ecology was positively correlated with socio-economic status such as education and financial situation. However, the importance of the utility of green spaces was less prevalent among original villagers and settlers. Moreover, we found that the percentage of green spaces of settlers is slightly higher than that of original villagers. The results of factor analysis revealed that socio-economic status can influence respondents’ attitudes towards green spaces. It suggests to increase ecological awareness of residents, especially for new settlers, and promote good management techniques for green spaces. This study can improve the awareness of urban planners about the importance of green spaces in suburban areas.

Open Access: Yes

DOI: 10.1016/j.regsus.2024.100180

Developing a Consistent and Transparent Corporate Sustainability Rating System with a Sector-Agnostic Approach

Robert Rickards Bence Lukács

Publication Name: Journal of Sustainability Research

Publication Date: 2025-09-01

Volume: 7

Issue: 3

Page Range: Unknown

Description:

Background: Development of objective, quantitative sustainability reporting scores for international companies has to be based on legal, regulatory, and public policy standards as well as focused exclusively on environmental, social, and governance (ESG) issues. The key performance indicators (KPIs) developed here differ from traditional agencies’ rating schemes in that they are equally applicable across industrial sectors. They measure performance in terms of several environmental Global Reporting Initiative (GRI) indicators. The KPIs quantify performance by systematically linking corporate revenues with sustainability metrics, thereby yielding readily comparable, numerical scores. Methods: This report illustrates their utility with data on carbon dioxide (CO2) emissions from leading companies within the S&P Global ESG ranking for 2023. Results: The findings reveal significant gaps in managing Scope 3 emissions, which dominate the value chain and present the greatest challenge for corporate sustainability. These disparities highlight the need for improved data transparency and harmonized reporting standards to ensure consistent and actionable sustainability assessments. Conclusions: By bridging these gaps, the KPIs enable more equitable comparisons across industries and encourage better alignment of corporate strategies with global climate objectives. The additional transparency and insights in turn afford investors, managers, policy makers, and other stakeholders’ better information for their decision making.

Open Access: Yes

DOI: 10.20900/jsr20250054

Comparison of Data Visualization Platforms Through European Traffic Data

Eniko Nagy Gombos Tamas Ferenc Gyorgy Molnar

Publication Name: Iccc 2024 IEEE 11th International Conference on Computational Cybernetics and Cyber Medical Systems Proceedings

Publication Date: 2024-01-01

Volume: Unknown

Issue: Unknown

Page Range: 43-48

Description:

The most important and valuable resource in the 21st century is data. The age of the internet brought us an era in which humans, within a foreseeable time, are unable to process the vast amount of data that we produce. It's important to understand the data and statistics we have because it can help a company make a well thought out decision on a given dilemma, which is based on reality and data. When choosing a data visualisation platform, the purpose of the application, the type of data and the user needs are also key factors. For the visualisation of traffic data in Europe, a number of established platforms can be considered and are referred to in this paper. This article compares data visualisation platforms currently available and used in industrial environments with open source free platforms, using European traffic data.

Open Access: Yes

DOI: 10.1109/ICCC62278.2024.10582968

Study on Adult Chinchilla (Chinchilla lanigera) Preferences for Cages of Different Sizes

Zsolt Gerencsér Zsolt Matics Stanisław Łapiński Zsolt Szendrő

Publication Name: Animals

Publication Date: 2024-12-01

Volume: 14

Issue: 23

Page Range: Unknown

Description:

The study aimed to investigate adult chinchillas’ preferences when choosing between cages with different floor areas, heights, or both. The size of the cages with a larger floor area was double that of the standard-sized cages in the farms (0.25 and 0.50 m2), while their height was 2.4 times that of the standard-sized cages (0.4 and 1 m). The chinchillas (10–14 in each cohort) were housed in blocks of cages where they could move freely between the smaller and larger cages. The chinchillas’ location preferences were monitored continuously over five days using infrared video recording. The chinchillas were observed in the cages with smaller floor areas 1.9 and 2.7 times more frequently than in the larger ones (p < 0.001) during the dark (active) and light (resting) periods of the day, respectively. When the cage height was 0.4 m, they chose it 3.4 and 6.7 times more frequently, respectively, than the cage that was 1 m high (p < 0.001). When both the floor size and the height were increased, the chinchillas still favored the smaller and lower cages (p < 0.001). The study findings suggest that adult chinchillas show a preference for smaller and shorter cages when the small and large cages are not environment enrichment barren, especially during the rest period of the day, even when the floor area, height, or both are increased. In the future, it would be important to investigate different forms of cage enrichment.

Open Access: Yes

DOI: 10.3390/ani14233368

Two new species of Oribatella (Acari, Oribatida, Oribatellidae) from Guatemala

Sergey G. Ermilov Jenő Kontschán

Publication Name: International Journal of Acarology

Publication Date: 2024-01-01

Volume: 50

Issue: 6

Page Range: 515-521

Description:

Two new species of oribatid mites of the genus Oribatella (Oribatida, Oribatellidae)—O. paradechambrierisp. nov. and O. parastrinatiisp. nov.—are described, based on adults collected from rainforest litter in Guatemala. Oribatella paradechambrierisp. nov. is similar to O. dechambrieri but differs by the smaller body size, the length of the teeth of the lamellae, the relative length of the free distal and fixed mediobasal parts of the lamella, the size of the trapezoid region in basal part of the prodorsum, and the length of the interlamellar seta. Oribatella parastrinatiisp. nov. is similar to O. strinatii but differs by the smaller body size, the morphology of the rostrum, the morphology of the tutorial cusp, the presence of large dense foveolae in the centrodorsal part of the notogaster and between the genital and anal apertures, and dense short transverse ridges on the medioposterior part of the notogaster, and the number of genital setae. Oribatella dechambrieri is the first record of the species for Guatemala. The belonging of O. paradechambrieri to the genus Fenestrobates is discussed. http://www.zoobank.org/urn:lsid:zoobank.org:pub:5F474B0F-7E2B-42CC-9252-E5C41D17FE96.

Open Access: Yes

DOI: 10.1080/01647954.2024.2373983

Exploring the impact of compressibility on reconstructed porous materials: A numerical study

H. Szűcs

Publication Name: Journal of Engineering Research Kuwait

Publication Date: 2025-09-01

Volume: 13

Issue: 3

Page Range: 1987-2003

Description:

This study underscores fluid density's significance in CFD simulations for porous materials, addressing its impact on accuracy and computational efficiency. The paper proposes a tailored form of Navier-Stokes equations that accounts for fluid density's influence on CFD analyses of porous materials in industrial contexts, including cases where the solid phase is deformable. Numerical analyses demonstrate fluid density's significance (ρ≠constant) and explore the importance of the energy equation in governing equations. The energy equation is essential in setting up the governing equations, as it calculates thermal characteristic length based on cell temperatures. By examining various porous material samples, the study suggests a streamlined approach: employing a single coupled CFD-FEM simulation to directly determine each geometrical parameter. Additionally, the study investigates the capability to accurately simulate turbulent fluid motion at the pore scale and analyze the flow field characterization within porous media. Computational cost analyses underscore the advantages of coupled simulations, establishing their profitability over separate parameter-specific simulations.

Open Access: Yes

DOI: 10.1016/j.jer.2024.07.018

Head Checks and the Useful Life of Rails

Zoltán Major Ferenc Horvát Róbert Horváth

Publication Name: Chemical Engineering Transactions

Publication Date: 2023-01-01

Volume: 107

Issue: Unknown

Page Range: 295-300

Description:

Transport systems, including railways, are an important part of everyday life in modern societies. Whether it is passenger or freight transport, railways are an environmentally friendly solution with their robust throughput capacity and modern electrified lines. The significant changes in transport needs over the last fifty years have partly modified its role, increasing both track speed and axle load. Head Checks (HC) appeared on the MÁV (Hungarian Railway Corporation) network in the early 2010s. This phenomenon had been an unknown problem in Hungary before. Several cases abroad (e.g., a train derailment at Hatfield station in 2000 with four fatalities) have highlighted the extreme danger of this phenomenon. Materials and railway track experts at Széchenyi University have been working on the subject of HC defects in rail heads for several years. The results of research work carried out for MÁV Zrt. form the base of this article. The novelty of this article is the complexity consideration. Not only the structural changes of the rail material were investigated, but also the time/traffic load-dependent crack evolution was mathematically described. Based on the strategy outlined in the report of the research work, MÁV has taken up the fight against HC cracks, which were initially proliferating. The modern laboratory test in this article is based on the tests of Csizmazia and Horvát (2014). The stresses causing damage were investigated previously by Horváth and Major (2023). The economic analysis is based on Róbert Horváth's own calculation results.

Open Access: Yes

DOI: 10.3303/CET23107050