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Publications - 6515

Tensor Product Alternatives for Nonlinear Field-Oriented Control of Induction Machines

Miklós Kuczmann Krisztian Horvath

Publication Name: Electronics Switzerland

Publication Date: 2024-04-01

Volume: 13

Issue: 7

Page Range: Unknown

Description:

The paper presents a nonlinear field-oriented control technique based on the tensor product representation of the nonlinear induction machine model and the solvability of linear matrix inequalities. The nonlinear model has 32 quasi linear parameter-varying equivalent variants, and it is shown that only half of the models result in feasible controller. Two control goals are realized: torque control and speed control. The controller is a nonlinear state feedback controller completed by integral action. A new block diagram is investigated for speed control. The controller gains are designed by the solution of linear matrix inequalities to solve the Lyapunov inequality to obtain a stable and fast response and constraints on the control signal. The presented methods are verified and compared by simulations.

Open Access: Yes

DOI: 10.3390/electronics13071405

Law pertaining to political parties and political pluralism - Freedom of the foundation and functioning of political parties in post-communist Hungary

Péter Smuk

Publication Name: Acta Juridica Hungarica

Publication Date: 2007-03-01

Volume: 48

Issue: 1

Page Range: 71-85

Description:

This paper studies the law pertaining to political parties in Hungary, from the viewpoint of establishing and maintaining of political pluralism. In the period of 1989-1990, the transition from the one-party system to the democratic and pluralistic state of law could be followed up relative to the development of the law pertaining to the political parties, which is based on the rules that foreclose the contingent development of unconstitutional political system. The paper reviews the concept of the political party according to the constitutional law, the normative framework of functioning and the regulations of the internal organization of political parties. The provisions of primary importance concern: a) equality of political parties, b) forbidden purposes and instruments, c) rules of incompatibility, d) state subvention. Rules concerning the internal organization require the openness and the prevailing of democratic will-making also inside the political parties, so contribute to the maintaining the democratic competition of political parties. The author emphasizes the factors that determine multiparty-system, and argues that electoral thresholds and the effective method of state-financing of political parties contest the principle of equality and harm the fair-competition. Thresholds and subvention are both based on the effectiveness of political parties-though being capable to prevent the party system and the parliament from fragmentation, nonetheless, they prefer extensively, if not unconstitutionally, the political parties in the Parliament, so they can be seen as being designed to protect the current political elite. © 2007 Akadémiai Kiadó.

Open Access: Yes

DOI: 10.1556/AJur.47.2007.1.5

Benchmarking methodology for IPv4aaS technologies: Comparison of the scalability of the Jool implementation of 464XLAT and MAP-T

Ádám Bazsó G. Lencse

Publication Name: Computer Communications

Publication Date: 2024-04-01

Volume: 219

Issue: Unknown

Page Range: 243-258

Description:

A novel method is proposed for the performance and scalability measurements of the IPv4-as-a-Service (IPv4aaS) technologies. It works according to the dual Device Under Test (DUT) setup of RFC 8219 and is suitable for benchmarking any of the five IPv4aaS technologies: Combination of Stateful and Stateless Translation (464XLAT), Dual-Stack Lite (DS-Lite), Lightweight 4over6 (Lw4o6), Mapping of Address and Port with Encapsulation (MAP-E), and Mapping of Address and Port using Translation (MAP-T). The method is based on the reduction of the aggregate of Customer Edge (CE) and Provider Edge (PE) devices to a stateful network address translation from IPv4 to IPv4 (stateful NAT44) gateway. The most important advantage of the novel method is that a stateful NAT44 tester can be used instead of a technology-specific tester, which usually does not exist. The proposed method is validated by the examination of the performance and scalability of the Jool implementation of 464XLAT and MAP-T. Scalability is defined by both (1) how performance increases with the number of active Central Processing Unit (CPU) cores; and (2) how performance decreases with the increasing number of concurrent sessions. Maximum connection establishment rate and throughput are used as performance metrics. The scalability of 464XLAT and MAP-T is measured from 1 to 16 CPU cores and from 1 million to 256 million connections. The measurement details and results are fully disclosed and discussed.

Open Access: Yes

DOI: 10.1016/j.comcom.2024.03.007

Effect of Printing Parameters on the Tensile Mechanical Properties of 3D-Printed Thermoplastic Polyurethane †

László Lendvai Sándor K. Jakab

Publication Name: Engineering Proceedings

Publication Date: 2025-01-01

Volume: 113

Issue: 1

Page Range: Unknown

Description:

Thermoplastic polyurethane (TPU) filament was used to fabricate specimens through material extrusion (MEX)-based 3D printing technique with varying printing parameters. Nozzle diameters of 0.4 mm and 0.8 mm were used, while the printing infill orientation (also denoted as raster angle) was either parallel (0°) to the length of the specimens, perpendicular to it (90°), or at a 45° angle with alternating direction in each layer (±45°). Tensile tests were conducted to determine tensile strength, Young’s modulus, and elongation at break of the samples. The highest tensile strength was achieved using a 0.8 mm nozzle diameter and 0° raster angle, reaching 32.5 MPa, with a corresponding Young’s modulus of 145.8 MPa. Meanwhile, the sample with the lowest modulus (100.4 MPa) and tensile strength (17.8 MPa) was the one 3D-printed with a 0.4 mm nozzle and 90° raster angle.

Open Access: Yes

DOI: 10.3390/engproc2025113019

Emotion and Reasoning in Hungarian heart Metaphors

No authors available

Publication Name: Language, Expressivity and Cognition

Publication Date: 2023-01-01

Volume:

Issue:

Page Range: 17-35

Description:

Open Access: No

DOI: DOI not available

Determination of Optimal Process Parameters for L-PBF Produced 1.2709 Alloy †

Imre Fekete István Hatos András Lajos Nagy Balázs Lőrincz

Publication Name: Engineering Proceedings

Publication Date: 2025-01-01

Volume: 113

Issue: 1

Page Range: Unknown

Description:

For L-PBF (Laser Powder Bed Fusion) metal additive manufacturing (AM) the choice of available materials is still limited. 1.2709 maraging steel powders are widely used for injection molds and high-quality engineering parts. The quality of the parts produced by L-PBF are significantly affected by the process parameters. The aim of this research was to find optimal process parameters for producing 1.2709 tool steel at a layer thickness of 20 µm and to reveal the possible parameter settings yielding comparable build quality as the “EOS surface” parameter set at a layer thickness of 20 µm. Findings showed that too low or too high input energies produce improper parts. A large range of parameters produce good quality parts, of which the optimum parameters can be chosen.

Open Access: Yes

DOI: 10.3390/engproc2025113017

Measuring the Effectiveness of High-Intensity Virtual Training Programs in Stroke Survivors

Tamás Haidegger József Tollár Bence Csutorás Nándor Prontvai Blanka Törő Szilvia Kóra Petra Kós Barbara Kopácsi Veronika Keresztesy Júlia Kutas Dóra Kozma

Publication Name: Acta Polytechnica Hungarica

Publication Date: 2025-01-01

Volume: 22

Issue: 10

Page Range: 103-123

Description:

The objective of this paper is to determine and compare the effects of two high-intensity virtual training programs, with different frequencies and standard care after stroke. First-time ischaemic stroke patients in subacute stage were randomized into three groups: 1 session/day high-intensity virtual training (VT1; n=20), 2 sessions/day high-intensity virtual training (VT2, n=20), standard care (CON, n=20). Each group performed a 5-week-long training program (1 hour/session, 5 days/week). Results were measured before and after the interventions. Our primary outcome was the modified Rankin Scale (mRS), which indicates the degree of independence in daily activities and the severity of disability at stroke survivors. Secondary outcomes were the Barthel Index (BI), the EuroQoL Visual Analogue Scale (EQ VAS), the Berg Balance Scale (BBS), the 6-minute walking test (6mWT), the Beck Depression Inventory (BDI), and posturograpic examination in four different positions (WEO, WEC, NEO, NEC). VT2 and VT1 groups improved significantly all of the results (all p<0,05). The result of the mRS, BI, BBS, 6mWT, BDI improved significantly (all p <0.05) in CON group, but there was no clinically meaningful changes in EQ VAS, WEO, WEC, NEO, and NEC (all p>0.05).Comparing the groups’ measured 10 results: VT2 in 9 cases (mRS, BI, EQ VAS, BBS, 6mWT, BDI, WEC, NEO, NEC), VT1 in 5 cases (mRS, 6mWT, BDI, WEC, NEC) showed greater extent improvement than CON group, furthermore the improvements of mRS and BI were significantly higher at VT2, than at VT1 (all p<0.05). Our results show that the high-intensity virtual training programs could be good opportunities for subacute ischaemic stroke patients to improve their clinical symptoms, mobility, and quality of life. Furthermore, increasing daily frequency of the training, could also increase the beneficial effects. This research is particularly important because the utilized therapies have the potential to yield significant economic benefits, by reducing long-term healthcare costs and improving overall patient outcomes.

Open Access: Yes

DOI: 10.12700/APH.22.10.2025.10.7

Earthquake-Induced Waste Repurposing: A Sustainable Solution for Post-Earthquake Debris Management in Urban Construction

Nurullah Bektaş M. Shmlls

Publication Name: Buildings

Publication Date: 2024-04-01

Volume: 14

Issue: 4

Page Range: Unknown

Description:

Product sustainability has moved beyond being an elective preference to becoming a certain necessity. However, earthquakes in different regions, particularly Türkiye–Syria, Afghanistan, and Morocco, have produced a substantial amount of construction waste and debris. In the context of green urban initiatives and environmental preservation, theeffective management and reduction of environmental impact (EI) are imperative. This urgency underscores the significance of the study’s focus on a ten-story reinforced concrete (RC) dormitory building in Győr, Hungary, chosen as a case study. The research delves into the incorporation of three distinct concrete compositions through seismic design, aligning with the innovative approach of emphasizing recycled aggregate-based concrete to mitigate the EI. Utilizing AxisVM X7 and Revit software, the study meticulously created and analyzed a detailed building model, revealing a significant percentage (35%) and amount (1519.89 tons) of concrete waste that could be incorporated into construction. The results also showed a reduction in both total carbon emissions and the price of materials by falling 27.5% and 9.13%, respectively. We propose an eco-friendly way to effectively reuse debris from earthquakes, focusing on the case study of the 2023 Türkiye–Syria earthquake and encouraging resource efficiency while also addressing the construction waste problems that arise after an earthquake.

Open Access: Yes

DOI: 10.3390/buildings14040948

Metallographic and magnetic analysis of direct laser sintered soft magnetic composites

Imre Fekete L. K. Varga B. Kocsis

Publication Name: Journal of Magnetism and Magnetic Materials

Publication Date: 2020-05-01

Volume: 501

Issue: Unknown

Page Range: Unknown

Description:

In this present study, soft magnetic composite samples were made from iron-silicon alloys. For the purpose of optimizing 3D printing parameters, preliminary experiments were performed. Metallographic and computed tomography investigations were used to determine the appropriate sintering settings. Besides the microscopic and CT analysis, considering the permeability spectra have been compared to the samples.

Open Access: Yes

DOI: 10.1016/j.jmmm.2020.166425