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Found 6374 publications

Control of underactuated systems based on machine learning model: case studies

Ambrus Zelei

Publication Name: Multibody System Dynamics

Publication Date: 2025-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

Besides traditional modelling approaches, machine learning surrogate models have become widespread. In addition to existing concepts, this work investigates the use of neural networks (NNs) to replace dynamic equations in multibody systems. While physics-informed neural networks (PINNs) dominate recent literature, their constraint enforcement via cost-function penalties poses tuning challenges. This paper proposes an alternative: training NNs on data with intentional constraint violations to implicitly learn stabilisation, avoiding PINN limitations. The proposed concept is applied to the inverse dynamics control of underactuated systems, where the task is defined by servo-constraints. Using Scikit-learn’s MLP Regressor, we demonstrate NN-based surrogate modeling in three levels: 1) forward dynamics of minimum-coordinate models, 2) constrained models, and 3) the inverse dynamics control of underactuated multibody systems via servo-constraints, which is a classical approach not yet combined with NNs. The neural network model is used to represent the inverse dynamics model, for which training data are generated through forward dynamic simulations. The study demonstrates that low-degree-of-freedom planar systems can be approximated by middle-scale neural network models of a few hundred perceptrons, requiring training times of minutes on a personal computer. The proposed control architecture can stabilise the servo-constraints and track trajectories, even for non-collocated underactuated systems where traditional methods might fail. The results highlight a simple, industry-friendly path for NN-based MBD control.

Open Access: Yes

DOI: 10.1007/s11044-025-10116-7

Potential of Green Hydrogen Synthesis from Sewage Sludge: Assessing Emission Factors

Éva V.P. Rácz Gergely Zoltán Macher Dóra Sipos Judit Pécsinger Dalma Bódizs

Publication Name: Chemical Engineering Transactions

Publication Date: 2025-01-01

Volume: 119

Issue: Unknown

Page Range: 559-564

Description:

The study aims to explore the feasibility of synthesizing hydrogen from sewage sludge in EU countries, with a particular focus on assessing associated emission factors. This research is driven by the increasing interest in utilizing wastewater as a valuable resource for clean energy production in the context of the global energy transition. Despite the need for extensive treatment of the resulting sludge, research efforts are focused on the production of clean energy, particularly hydrogen. The research methodology uses statistical approaches to derive potential values from baseline data through emission factors and categorizes study areas based on this information. Europe produces approximately 10 million tons of sewage sludge annually, with Hungary contributing nearly a quarter of a million tons, hence this significant byproduct should be treated as a valuable resource in accordance with the principles of a circular economy. The paper delves into hydrogen generation from sewage sludge, specifically through anaerobic digestion, and thoroughly reviews and contrasts existing systems, examining key factors and prospects influencing hydrogen production efficacy within the EU context. Overall, this study addresses a topic of growing significance, offering insights beneficial for both policy formulation and practice in the spheres of energy management and environmental conservation, with a special emphasis on its application and implications for European Union countries.

Open Access: Yes

DOI: 10.3303/CET25119094

Metamodel-based Optimization of Anisotropic Rotor Axial Flux Permanent Magnet Synchronous Motors

Miklós Kuczmann Attila Nyitrai

Publication Name: Periodica Polytechnica Electrical Engineering and Computer Science

Publication Date: 2025-01-01

Volume: 69

Issue: 1

Page Range: 89-98

Description:

Axial flux motors have some significant advantages over radial flux motors in high torque-density applications. However, the optimization of axial flux permanent magnet synchronous motors is a challenging task; the analysis usually requires 3D finite element analysis or the application of the 2D multi-slice method. In this paper a novel single-surrogate multi-slice method (SS-MSM) is proposed for modeling anisotropic rotor axial flux permanent magnet motors. However, the general methodology can be applied to other axial flux motors as well. A model calibration methodology has been described where the SS-MSM parameters have been determined using a 2D finite element approach as a reference. The SS-MSM was found to be suitable for a fast and reasonably accurate approximation of the motor performance. Based on the described analysis method, an efficient optimization approach is proposed.

Open Access: Yes

DOI: 10.3311/PPee.36813

Analysis of financial performance of deposit banks in Turkey using multi-criteria decision-making methods

Judit Petra Koltai Hasan Tutar Batuhan Medetoğlu Yusuf Bahadır Kavas

Publication Name: Journal of International Studies

Publication Date: 2025-01-01

Volume: 18

Issue: 1

Page Range: 196-215

Description:

Financial performance analysis in the banking sector aims to determine the capacity for data-driven decision making. This study evaluates the financial performance of public and private deposit banks in Türkiye. In the study, we used the entropy method to determine performance weights. Then, we used the VIKOR technique, which integrates the entropy method with multi-criteria decision making. This integrated approach evaluates banks according to key dimensions such as profitability, liquidity, asset quality, and capital adequacy. We conducted the study on a sample of three public and eight private deposit banks operating in Türkiye. The data covers financial ratios starting from 2022. The findings show that two public banks have high financial performance, while publicly owned deposit banks have stronger financial performance than their privately owned counterparts. The findings provide valuable insights into the Turkish banking sector's financial stability and competitive positioning. The results of the study can guide bank managers and regulatory authorities.

Open Access: Yes

DOI: 10.14254/2071-8330.2025/18-1/12

Examining gender equality in tourism management for Hungarian regions

Botond Géza Kálmán Kőműves Zsolt Szécsi Gabriella Pálmai László

Publication Name: Statisztikai Szemle

Publication Date: 2025-01-01

Volume: 103

Issue: 11

Page Range: 1094-1110

Description:

This study explores the impact of gender inclusivity on workplace experiences among female leaders in the Hungarian tourism management sector, with a particular focus on perceived discrimination, job insecurity, and family-related obligations. Employing a mixed-methods approach, the research combined structured questionnaire data (n = 102) with qualitative insights derived from thematic content analysis of open-ended responses. Analytical methods included descriptive statistics, ANOVA, regression analysis, and cluster analysis. Findings indicate that 75% of respondents reported gender-based discrimination, especially in promotion processes, while 65% identified family responsibilities as significant barriers to career advancement. Marked regional differences emerged: Central Hungary exhibited a more inclusive work environment, with lower levels of perceived discrimination and greater job security compared to northern regions. Inclusive organizational practices were positively associated with career satis faction and tourism-related performance. The results underscore that advancing gender equality is not only a matter of social justice but also a key determinant of economic performance and regional competitiveness. The study recommends reinforcing family-friendly and inclusive workplace cultu res and calls for regionally differentiated policy interventions.

Open Access: Yes

DOI: 10.20311/stat2025.11.hu1094

A Comprehensive Model for the Assessment of Digitalization Transformation in Supply Chain Management †

László Buics Ngoc Quynh Tran Nguyen

Publication Name: Engineering Proceedings

Publication Date: 2025-01-01

Volume: 113

Issue: 1

Page Range: Unknown

Description:

The rise of Industry 4.0 has made digital transformation a critical element of modern supply chain management, offering organizations a pathway to competitive advantage. While the prior literature has examined aspects of digitalization, few studies present a comprehensive view of the transformation process through to its practical application. This study proposes and aims to validate a digital transformation model developed by the author, based on a systematic literature review of 284 articles from Scopus and Web of Science. The model outlines a progression from data management to the integration of enabling technologies, culminating in enhanced supply chain decision-making. It introduces three key metrics—readiness, adoption, and Digital Maturity—to guide companies through distinct stages of transformation. Validation will be conducted using a mixed-methods approach, combining expert interviews and a quantitative survey with SCM professionals. This study offers both a theoretical framework and practical roadmap to support organizations in evolving their digital transformation strategies.

Open Access: Yes

DOI: 10.3390/engproc2025113064

Evaluating Stakeholder Opinion on Traffic Engineering Devices to Improve Pedestrian Crossing Safety Around Schools in Small Villages

Emese Makó Kurmangaliyev Zhiger

Publication Name: Lecture Notes in Networks and Systems

Publication Date: 2025-01-01

Volume: 1258 LNNS

Issue: Unknown

Page Range: 58-68

Description:

Despite the greater attention and investment in pedestrian safety measures typically allocated to urban areas, rural villages are frequently overlooked in this respect. A school zone typically applied in urban contexts, refers to a road network surrounding a school where younger pedestrians are likely to be present. The research objective was to gain insight into the traffic preferences of key stakeholders, including teachers, pupils, parents, and representatives of the road authority, regarding the safety of pedestrian crossings in the vicinity of small village schools. A survey was conducted at selected primary schools with relatively high traffic volumes and a high risk of pedestrian accidents. The survey evaluated six different types of designated pedestrian crossings equipped with different traffic engineering devices. The results of the Spearman rank correlation analysis indicate a high degree of alignment between the perspectives of parents and school pupils. At the same time, those of road professionals diverge significantly from those of parents. The teachers’ perspectives exhibit moderate alignment with those of school pupils and road professionals, positioning them in a middle ground between these two groups. The findings demonstrate that the traffic engineering measures deemed safe by road users do not always correspond with those preferred by road professionals. A discrepancy between perceived and actual safety is frequently observed. To address this discrepancy, it is crucial to educate pedestrians about the advantages of safety devices that engineers have identified as effective. Concurrently, it would be prudent for those responsible for the management of roadways to give due consideration to the preferences of pedestrians during their planning activities.

Open Access: Yes

DOI: 10.1007/978-3-031-81799-1_6

INDUSTRY 5.0 AS A HUMAN-CENTRIC DIRECTION FOR SOCIAL AND LABOR ENTITIES TRANSFORMATIONS

Leonid Melnyk Oleksandr Kubatko Lyudmila Kalinichenko Sándor Remsei

Publication Name: Problems and Perspectives in Management

Publication Date: 2025-01-01

Volume: 23

Issue: 4

Page Range: 290-300

Description:

The interaction of humans with artificial intelligence and cyber-physical systems opens the way to understanding the role of humans in modern industrial ecosystems. The research purpose is to examine the roles and functions of humans in implementing Industry 5.0 through the analysis of personality transformations in social and labor entities. A structured review methodology that synthesizes existing research on Industry 5.0 as a human-centric direction using systematic and transparent procedures (framing the question, identifying relevant publications in the Scopus database, summarizing the evidence, and interpreting the findings) is used. Within Industry 5.0, the physiological needs of a bio-human (needs for food, water, living conditions, etc.) and the technocratic interests of a labor-human (the desire to earn money, career growth, prestige, etc.) are overwhelmed in terms of time and effort by the socio-human personality needs (intellectual development, the realization of creative abilities, and obtaining knowledge). In complex technical tasks and strategic decision-making processes, humans continue to play a key role, emphasizing that full automation is not possible in all areas, and a human-centric approach remains the basis of production systems. Among the key personality skills needed for Industry 5.0 are analytical and creative thinking, the ability to design technology, critical thinking, ability to solve complex problems, leadership skills, emotional intelligence, and generating new ideas. Industry 5.0 promotes the consumption of mainly information and services dictated by the informational (spiritual) nature of the personality and relatively depresses the use of materials and services, dictated by the material nature of the human-bio.

Open Access: Yes

DOI: 10.21511/ppm.23(4).2025.21

Q-Fractional Hesitant Fuzzy Sets and Their Correlation Coefficients: Multi-Criteria Decision Making Technique for Selection of Agricultural Land to Cultivate Apples Crops

Dragan Pamucar Khizar Hayat Nadeem Ajaib Kamran Kausar

Publication Name: IEEE Access

Publication Date: 2025-01-01

Volume: 13

Issue: Unknown

Page Range: 134057-134069

Description:

The q-Fractional Fuzzy Sets (q-FrFSs) offers information in Membership Grade (MG) and Non-membership Grade (NMG) of an object; however, both grades have the hesitancy factor because complex information usually does not give single MG and single NMG. Therefore, in this study we initiate the concept of q-Fractional Hesitant Fuzzy Sets (q-FrHFSs) and its basic properties. In q-FrHFSs not only hesitancy factor is taken into account but it also consider all possible values of uncertainties in {0,1}× {0,1}. Thus Correlation Coefficients (CCs) on q-FrHFSs are necessary to cope uncertain information with hesitancy, MGs and NMGs. In this study we introduce two types of CCs namely CCs on q-FrHFSs and weighted CCs on q-FrHFSs. We investigate underlying properties of these CCs and give a MCDM method on q-FrHFSs environment. We consider an application of our method to agricultural land selection across a set of cities for cultivation of apples crop. At the end, we compare our method of q-FrHFSs to some existing frameworks.

Open Access: Yes

DOI: 10.1109/ACCESS.2025.3582884