Search Everything

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

Publications - 6342

Sequential model predictive direct speed control of PMSM

Karol Kyslan Krisztian Horvath Lukáš Pancurák Krisztián Horváth

Publication Name: Scientific Reports

Publication Date: 2026-12-01

Volume: 16

Issue: 1

Page Range: Unknown

Description:

Finite control set model predictive control (FCS-MPC) has emerged as a powerful strategy for permanent magnet synchronous motor (PMSM) drives. However, its performance strongly depends on appropriately chosen weighting factors, which directly affect control quality and, in some cases, may even lead to instability. Despite the crucial role of weighting factors, there is no systematic or generally accepted procedure for selecting their values, which limits the robustness and practical applicability of conventional FCS-MPC methods. To overcome this limitation, this paper presents the experimental validation of a sequential direct speed predictive control strategy for PMSM. The individual cost functions are evaluated sequentially, thereby tuning is simplified and weighting factors are reduced. Experimental results show that the original version of sequential direct speed control, as proposed in the literature, exhibits promising dynamic performance but suffers from instability and current ripples under certain conditions. To address these issues, an enhanced version of the sequential direct speed predictive control is proposed in the paper. It effectively suppresses instabilities and enhances the speed dynamic response of the drive. The proposed approach was experimentally validated using the OP 5600 rapid control prototyping platform running RT-LAB software and a 1.1 kW PMSM machine.

Open Access: Yes

DOI: 10.1038/s41598-026-39256-2

Cloud spot instance price forecasting multi-headed models tuned using modified PSO

Nebojsa Bacanin Dragan Pamucar Luka Jovanovic Miodrag Zivkovic Ali Elsadai Mohamed Salb Vladimir Simic

Publication Name: Journal of King Saud University Science

Publication Date: 2024-12-01

Volume: 36

Issue: 11

Page Range: Unknown

Description:

The increasing dependence and demands on cloud infrastructure have brought to light challenges associated with cloud instance pricing. The often unpredictable nature of demand as well as changing costs of supplying a reliable instance can leave companies struggling to appropriately budget to support a healthy cash flow while maintaining operating costs. This work explores the potential of multi-headed recurrent architectures to forecast cloud instance prices based on historical and instance data. Two architectures are explored, long short-term memory (LSTM) and gated recurrent unit (GRU) networks. A modified optimizer is introduced and tested on a publicly available Amazon elastic compute cloud dataset. The GRU model, enhanced by the proposed modified approach, had the most impressive outcomes with an MAE score of 0.000801. Results have undergone meticulous statistical validation with the best-performing models further analyzed using explainable artificial intelligence techniques to provide further insight into model reasoning and information on feature importance.

Open Access: Yes

DOI: 10.1016/j.jksus.2024.103473

Evaluating Sustainable Online Education: A Cross-Disciplinary Analysis of IT Device Utilization among Slovakian and Hungarian University Students

Ondrej Takáč Nóra Gombköto Iveta Štempeľová

Publication Name: Sustainability Switzerland

Publication Date: 2024-01-01

Volume: 16

Issue: 2

Page Range: Unknown

Description:

By the onset of the 21st century, online presence had become prevalent in higher education, with the COVID-19 pandemic further accelerating this trend. However, the success of online education and its assessment by students can differ significantly from region to region and according to the field of study. This can be influenced by students’ habits of using IT devices, but it can also occur the other way around. In this research, experiences related to online education were examined in the fields of Informatics, Agriculture and Pharmacy education at two higher-education institutions in Slovakia and one in Hungary, considering the environmental and social sustainability implications. In the study, in addition to simple statistical methods, a cross-tabulation analysis was carried out using Cramer’s V method. The results have shown that the students of the investigated institutions confidently navigate the online world; they are conscious users of IT tools without being addicted. A total of 74% of students in Mosonmagyaróvár believe they possess sufficient information about the risks associated with computers, mobile phones, and the Internet, whereas only 34% of students in Košice share the same sentiment. The reason for the differences between these characteristics can be attributed to the specialties of the different majors, and not to those arising from regional differences, raising important questions about the ecological sustainability of online education practices. A relatively great consistency can be observed in the assessment of online learning among students from the three institutions, with approximately 85% expressing overall satisfaction with the online learning experience. The easier availability of study materials and savings on travel are mentioned as advantages, contributing to economic sustainability. However, separation from their mates and the lack of practical training may be regarded as a disadvantage for them, as they seem to have a preference for face-to-face training. Overall, it may be concluded that purely online training in the fields of Informatics, Agriculture, and Pharmacy training is not feasible for the time being, necessitating a balanced and sustainable approach for the future.

Open Access: Yes

DOI: 10.3390/su16020699

The Assessment of Economic Performance in the Sustainability Reports of Financial Institutions

Katatlin Vargáné Kiss

Publication Name: Chemical Engineering Transactions

Publication Date: 2023-01-01

Volume: 107

Issue: Unknown

Page Range: 511-516

Description:

Sustainability reporting has gained worldwide importance for corporations over the past decade. This required the development of frameworks and standards for consistent disclosure. Non-financial or triple-bottom-line reporting reveals how firms, in general, incorporate SDGs in their reports and in what way they are assessed in terms of importance. While earlier sustainability issues were an integral part of the CSR activities published in the annual reports, these days, they are issued as separate reports due to the increased attention of stakeholders. Regarding financial institutions, the focus has gradually shifted from profitability issues to responsible investment and sustainable finance. Based on the content analysis of the most recent sustainability reports of the largest commercial banks in Hungary, including also the subsidiaries of foreign parent banks, the paper aims to provide a comprehensive overview of their economic impacts. Comparing the reports based on qualitative content analysis, the paper attempts to illustrate to what extent they comply with the GRI standards, what material topics are given priority in their reporting, and which sustainable development goals (SDGs) enjoy preference. The results obtained underpin the fact that, as opposed to sectors other than finance, sustainability endeavours related to economic growth are at the forefront compared to social and environmental issues.

Open Access: Yes

DOI: 10.3303/CET23107086

Magnetic equivalent circuit and finite element modelling of anisotropic rotor axial flux permanent magnet synchronous motors with fractional slot distributed winding

Miklós Kuczmann Attila Nyitrai

Publication Name: Iet Electric Power Applications

Publication Date: 2023-05-01

Volume: 17

Issue: 5

Page Range: 709-720

Description:

Axial flux motors have been in the focus of many research work due to their promising properties when compared to conventional radial flux machines. Axial flux permanent magnet synchronous motors (AFPMSM) studied in the literature were mostly limited to surface-mounted permanent magnet machines (SPMSM), excluding only a few studies about axial flux internal permanent magnet (AFIPM) or permanent magnet-assisted synchronous reluctance (AFPMaSynRM) machines. Since numerous rotor topologies have been proposed and investigated in case of radial flux motors, analogous design methodologies can be developed in case of axial flux motors with rotor saliency. The parametrisation and modelling of a magnetically anisotropic rotor axial flux motor are presented. This approach is described generally and the method is applied to an example motor geometry. The results were validated by FEA (Finite Element Analysis), using the 2D multi-slice and 3D modelling approaches. The modelling error was calculated and the analytical and numerical methods were compared. It was found that the proposed model was suitable for calculating important parameters of the anisotropic rotor axial flux permanent magnet synchronous motor (AnR-AFPMSM) during the design process.

Open Access: Yes

DOI: 10.1049/elp2.12298

The Forerunner UAV Concept for the Increased Safety of First Responders

No authors available

Publication Name: International Conference on Vehicle Technology and Intelligent Transport Systems, VEHITS - Proceedings

Publication Date: 2021-01-01

Volume: 2021-April

Issue:

Page Range: 362-369

Description:

This paper proposes a novel Forerunner UAV concept to increase the safety of first responders by monitoring the road in front of their emergency ground vehicle (EGV) and notifying the driver about any violation of his/her right of way or approaching danger. The developments are conducted in an R&D project in Hungary. The proposed UAV for the planned urban demonstration is a hexacopter with triple redundant architecture applying a gimbaled camera to monitor the surroundings. In the cooperative control of the EGV and UAV the UAV must fly in front of the EGV which is possible through wireless communication of route data and velocity. Besides the real system a computer simulation representation is also applied including CARLA and Matlab to make exhaustive tests of the system capabilities. Increased attention is devoted to the possible wireless communication solutions as these are safety critical parts of the system. The article ends with the lists of planned simulation and real test scenarios to evaluate the system.

Open Access: No

DOI: DOI not available

Effect of Spirulina platensis on the content values of wheat bread

Székelyhidi Rita Beatrix Sik G. Takács

Publication Name: Scientific Reports

Publication Date: 2026-12-01

Volume: 16

Issue: 1

Page Range: Unknown

Description:

Due to their nutritional composition, algae are promising ingredients in the development of new foods. The aim of our work was to prepare bread containing Spirulina platensis (new name Arthrospira platensis) in different percentages (0.5, 1.0, 2.5%) within the framework of the MSZ 6369/8-1988 standard, and to determine its content (dry matter, ash, fat, protein/nitrogen, fiber content, carbohydrate content, and polyoxide, color), as well as its texture and color. Furthermore, we assessed consumer opinions through a sensory evaluation. We found that increasing the width and shape fraction while decreasing the height. The results showed that the antioxidant and polyphenols properties of Spirulina-enriched breads increased. The protein, nitrogen, fibre content increased and carbohydrate, energy value properties of Spirulina-enriched breads decreased with increasing concentration of algae. Spirulina powder increased the greenness of the bread and decreased the lightness of the crumb. The hardness, cohesiveness and springiness increased with the addition of Spirulina to bread, while the gumminess and chewiness values became lower compared to the control. Consumer acceptability results showed that the addition of Spirulina at a concentration of 2.5% significantly reduced overall acceptance. Our results indicated that Spirulina cyanobacteria, can be a suitable raw material for making bread, also from the point of view of healthier and sustainable nutrition.

Open Access: Yes

DOI: 10.1038/s41598-026-43788-y

Probabilistic Topology Optimization of Steel I-Beam Web Configurations Under Varied Load Positions

Majid Movahedi Rad Muayad Habashneh

Publication Name: Advances in Transdisciplinary Engineering

Publication Date: 2024-01-01

Volume: 59

Issue: Unknown

Page Range: 30-36

Description:

This study investigates the impact of uncertain load positions through an innovative optimization technique. It seamlessly integrates reliability-based design into the optimization of the structural topology, with a specific focus on the web portion of steel I-beams and including geometrical imperfection analysis. The study operates under the premise that the applied load is randomly positioned, engaging in a comprehensive probabilistic analysis. This methodology extends its considerations to additional factors, such as material properties, volume fraction, and geometric imperfections. The assumption of a normal distribution for each of these parameters aids in quantifying uncertainties. Moreover, the proposed work leverages the notion of plastic ultimate load multipliers to illustrate how the algorithm can improve the performance of steel beams. To evaluate the algorithm, the results of a benchmark problem were meticulously analyzed. While exploring the probabilistic nature of externally applied force positions, a numerical example was conducted involving a steel I-beam within the context of reliability-based imperfect geometry topology optimization. The outcomes of the proposed method underscore that the integration of probabilistic design significantly influences the topology optimization process.

Open Access: Yes

DOI: 10.3233/ATDE240523

SCHEDULING OF WASTE WOOD PROCESSING FACILITIES WITH OVERLAPPING JOBS

No authors available

Publication Name: Proceedings of the 16th International Symposium on Operational Research in Slovenia, SOR 2021

Publication Date: 2021-01-01

Volume:

Issue:

Page Range: 321-326

Description:

An important phase in most waste wood value chains is the processing of bulk waste from various sources, usually by means of shredding. This paper presents a method for scheduling the machines in such a waste wood processing facility, where incoming deliveries of different types of wood are processed by a series of treatment and transformation steps to produce shredded wood. A mathematical model is presented for the problem, that allows overlaps between consecutive steps to optimize resource flow through the system. The efficiency of the model is presented on randomly generated instances.

Open Access: No

DOI: DOI not available