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Found 6674 publications

Two operating states-based low energy consumption vehicle control

Istvan Lakatos Erno Horváth Peter Koros Ferenc Szauter

Publication Name: Proceedings of the ASME Design Engineering Technical Conference

Publication Date: 2017-01-01

Volume: 9

Issue: Unknown

Page Range: Unknown

Description:

The current paper presents a realization of a complex vehicle control task. The goal was to consume the lowest possible energy in a less than 100 kg, wheel hub motor-driven vehicle. The realization is based on two distinguishable operating states which states characterizes well the driving cycle of the vehicle. The main contribution of the proposed method is that it reliably estimates the external loads which interacts the vehicle, the controller can adapt to this changes thus it can guarantee the minimal energy consumption. The vehicle described in the paper is a participant at the Shell Eco-marathon Europe competition in Urban Concept - Battery Electric category.

Open Access: Yes

DOI: 10.1115/DETC2017-67978

Massive Open Online Courses (MOOCs) for Ethiopian Educators: Evaluating MOOCs as a global development tool

Seyoum Teffera Mengesha Sándor Remsei Belaynew Asrie Mola Eva Berde

Publication Name: Research in Globalization

Publication Date: 2024-12-01

Volume: 9

Issue: Unknown

Page Range: Unknown

Description:

This study examines how global educational technologies interact with local development priorities through the lens of Massive Open Online Courses (MOOCs) in Ethiopian higher education teacher training. While digital learning platforms promise to democratize education globally, their effectiveness depends critically on alignment with local institutional contexts and development needs. Using survey data from 164 educators across 15 public universities, we investigate how institutional contexts shape technology integration patterns. Our analysis, integrating development theory with technology acceptance models, reveals three critical dimensions: the gap between awareness and participation reflects broader implementation challenges; previous experiences with development initiatives significantly influence adoption patterns; and state support proves crucial for enabling participation. While MOOCs offer potential for professional development in resource-constrained contexts, their effectiveness depends on complex interactions among infrastructure quality, institutional capacity, and material conditions. These findings contribute to the theoretical understanding of how global technological innovations interact with local institutional contexts to produce varied development outcomes, while offering practical insights for educational technology implementation in the Global South.

Open Access: Yes

DOI: 10.1016/j.resglo.2024.100263

An Analytical Method for Determining the Stress–Strain State of a Subgrade with Combined Reinforcement

Szabolcs Fischer Dmytro Kurhan Ahmad Alkhdour Oleksii Tiutkin

Publication Name: Infrastructures

Publication Date: 2024-12-01

Volume: 9

Issue: 12

Page Range: Unknown

Description:

This article presents the fundamentals of an analytical method for determining the stress–strain state of a railway subgrade reinforced with geosynthetic material. The reinforcement described is a combined system where the geosynthetic material forms an open shell containing a layer of compacted crushed stone. The overall stress–strain state is proposed to be viewed as a superposition of two states of the subgrade. The stresses and displacements in the first state refer to the unreinforced subgrade (matrix), while the stress–strain state of the reinforcement element is determined using analytical constructs from composite theory. The dependencies of the overall stress–strain state are applied in a numerical analysis, which confirms the positive effect of reduced subgrade deformations. A small-scale experimental model further validates the accuracy of the analytical approach.

Open Access: Yes

DOI: 10.3390/infrastructures9120240

Full-surface geometric analysis of DMLS-manufactured stainless steel parts after post-processing treatments

Zoltán Weltsch Valentin Szabó

Publication Name: Results in Engineering

Publication Date: 2025-09-01

Volume: 27

Issue: Unknown

Page Range: Unknown

Description:

The study examines the geometric behavior of corrosion-resistant steel components manufactured using the DMLS (Direct Metal Laser Sintering) process after various post-treatment methods. Full-surface 3D optical scanning was used to evaluate geometric deviations before and after three different treatments: stress relief heat treatment, immediate base plate removal, and natural aging. The results showed that heat treatment amplified the distortions caused by existing residual stresses, with elliptical deformation nearly doubling (i.e., deteriorating by approximately 200 %). Immediate removal resulted in asymmetrical, teardrop-shaped distortion that exceeded the ±0.1 mm tolerance limit. Natural aging effectively stabilized the geometry, with circularity deviation remaining within the ±0.1 mm limit. The results highlight the critical role of thermal management and post-processing in ensuring the dimensional accuracy of DMLS parts. The research demonstrates the advantages of full-surface, high-precision optical metrology in the detailed analysis of shape changes occurring during additive manufacturing, with the maximum permissible error of the measuring system limited to 0.01 mm in our measurements.

Open Access: Yes

DOI: 10.1016/j.rineng.2025.106084

Characterisation of Inhomogeneous Plastic Deformation of AlMg Sheet Metals during Tensile Tests

Szabolcs Szalai Dóra Harangozó Imre Czinege

Publication Name: Iop Conference Series Materials Science and Engineering

Publication Date: 2020-08-25

Volume: 903

Issue: 1

Page Range: Unknown

Description:

The Portrevin-Le-Chatelier (PLC) effect was analysed quantitatively in the selected AlMg alloys with Mg-content between 2,8-4,6%. The propagation and characteristics of PLC bands were detected by digital image correlation (DIC) technique and the parameters of the bands were evaluated from strain distributions of tensile test specimens. In parallel, stress-strain curves were analysed evaluating stress serrations. The numerically defined parameters of changes in stress and strain were used for characterising the PLC effect on the behaviour of different sheet metals. General statements of literature were numerically proven for the tested materials and the effect of magnesium content on stress amplitude was analysed in detail.

Open Access: Yes

DOI: 10.1088/1757-899X/903/1/012023

Residual stresses in carburised, carbonitrided and case-hardened components (Part 2)

Tamás Réti

Publication Name: Heat Treatment of Metals

Publication Date: 2004-03-11

Volume: 31

Issue: 1

Page Range: 4-10

Description:

An overview is given of the significant progress in research focused on the assessment of residual stress effects in case-hardened components. Focus is on relevant computational models intended to simulate stress evolution during heat treatment.

Open Access: Yes

DOI: DOI not available

Modelling of virtualized servers

Ákos Kovács Gabor Lencse

Publication Name: 2015 38th International Conference on Telecommunications and Signal Processing Tsp 2015

Publication Date: 2015-10-09

Volume: Unknown

Issue: Unknown

Page Range: 421-425

Description:

The virtualized systems are one of the key elements of the next generation IT infrastructures. Modeling it will prevent mistakes, and oversized management. Opennebula is one of the most current open source cloud management solutions. Together with Haizea, they are a powerful tool to model and manage a virtualized infrastructure trough the API of Openebula. Haizea has multiple scheduler algorithms that are more effective than that of Opennebula. We performed several experiments to compare simulation and measurement capabilities of Haizea and we highlighted some difference between them which can be reduced if required.

Open Access: Yes

DOI: 10.1109/TSP.2015.7296296

Reinforcement of RC Two-Way Slabs with CFRP Laminates: Plastic Limit Method for Carbon Emissions and Deformation Control

Oveys Ghodousian Marco Domaneschi Zahraa Saleem Sharhan R. M. Movahedi Raffaele Cucuzza

Publication Name: Buildings

Publication Date: 2024-12-01

Volume: 14

Issue: 12

Page Range: Unknown

Description:

Carbon-fiber-reinforced polymer (CFRP) laminates have gained attention for their potential to reduce carbon emissions in construction. The impact of carbon-fiber-reinforced polymer (CFRP Laminate) on carbon emissions and the influence of elasto-plastic analysis on this technique were studied in this research. This study focuses on how CFRP can affect the environmental footprint of reinforced concrete structures and how elasto-plastic analysis contributes to optimizing this strengthening method. Four flat RC slabs were created to evaluate this technique in strengthening. One slab was used as a reference without strengthening, while the other three were externally strengthened with CFRP. The slabs, which were identical in terms of their overall (length, width, and thickness) as well as their flexural steel reinforcement, were subjected to concentrated patch load until they failed. The strength of two-way RC slabs was analyzed using a concrete plastic damage constitutive model (CDP). Additionally, CFRP strips were applied to the tension surface of existing RC slabs to improve their strength. The load–deflection curves obtained from the simulations closely match the experimental data, demonstrating the validity and accuracy of the model. Strengthening concrete slabs with CFRP sheets reduced central deflection by 17.68% and crack width by 40%, while increasing the cracking load by 97.73% and the ultimate load capacity by 134.02%. However, it also led to a 15.47% increase in CO2 emissions. Also, the numerical results show that increasing the strengthening ratio significantly impacts shear strength and damage percentage.

Open Access: Yes

DOI: 10.3390/buildings14123873

Randomized, double-blind, placebo-controlled, proof-of-concept study of the cortical spreading depression inhibiting agent tonabersat in migraine prophylaxis

M. D. Ferrari P. J. Goadsby J. G. Mills Attila Csanyi J. Olesen

Publication Name: Cephalalgia

Publication Date: 2009-07-01

Volume: 29

Issue: 7

Page Range: 742-750

Description:

Tonabersat is a novel putative migraine prophylactic agent with an unique stereospecific binding site in the brain. Tonabersat has been shown, in animal models, to inhibit experimentally induced cortical spreading depression, the likely underlying mechanism for migraine aura, and cerebrovascular responses to trigeminal nerve stimulation. The aim was to study the potential for tonabersat as a migraine preventive. A randomized, double-blind, placebo-controlled, multicentre, parallel group study recruited patients with migraine with and without aura experiencing between two and six migraine attacks per month. After a 1-month baseline they received tonabersat 20 mg daily for 2 weeks and 40 mg daily for a further 10 weeks. The primary end-point was the change in mean number of migraine headache days between the third month and the baseline period in the intention-to-treat population comparing the placebo (n = 65) and tonabersat (n = 58) groups. At the primary end-point there was a 1.0-day (95% confidence interval -0.33, 2.39; P = 0.14) difference in reduction in migraine days between tonabersat and placebo. There were 10 secondary efficacy end-points, of which two were statistically significant. In month 3 of treatment, the responder rate, defined as a 50% reduction in migraine attacks, was 62% for tonabersat and 45% for placebo (P < 0.05), and the rescue medication use was reduced in the tonabersat group compared with placebo by 1.8 days (P = 0.02). Placebo responses were particularly high for all end-points. At least one treatment-emergent adverse event was reported in the tonabersat group in 61% of patients compared with 51% in the placebo group; none was worrisome. Placebo responses were unexpectedly high in this trial, complicating straightforward interpretation of the study results. The good tolerability and promising efficacy results support further exploration of higher doses of tonabersat in larger controlled trials. © Blackwell Publishing Ltd.

Open Access: Yes

DOI: 10.1111/j.1468-2982.2008.01804.x