Search in Publications

Found 6278 publications

Numerical Simulation of Coupled Electromagnetic and Thermal Problems in Permanent Magnet Synchronous Machines

Lotfi Abdelhakim Daniel Marcsa V. Chabannes C. Prudhomme Zoltán Horváth

Publication Name: Lecture Notes in Computational Science and Engineering

Publication Date: 2021-01-01

Volume: 139

Issue: Unknown

Page Range: 693-701

Description:

The main objective of our task is to develop mathematical models, numerical techniques to analyse the thermal effects in electric machines, to implement the developed algorithm in multiprocessor or multi-core environments and to apply them to industrial use cases. In this study, we take into account coupled character of the electromagnetic and thermal features of the physical process. Both thermal and electromagnetic processes are considered transient, solved by means of the FEM method on independent meshes and the time-discretization is realized using time operator splitting. Two examples are presented to assess the accuracy of the developed coupled solvers and the numerical results are compared with the experimental ones, which are obtained from a prototype machine.

Open Access: Yes

DOI: 10.1007/978-3-030-55874-1_68

A simple and accurate contactless frequency and amplitude meter

Tolnai László Marczy László

Publication Name: Review of Scientific Instruments

Publication Date: 1997-01-01

Volume: 68

Issue: 2

Page Range: 1303-1306

Description:

This study describes a measuring instrument based on the Michelson interferometer. It is able to measure the amplitude-time function or the resonance curve in a wide frequency range simultaneously depending on the amplitude of the vibration without any kind of mechanical contacts. Compared with other instruments based on similar principles, it has the advantage of not being a heterodyne interferometer, that is of using only the phenomenon of classic interference instead of the frequency of Doppler shift of the reflected light. The reflective surface of the oscillating object or the mirror glued thereon may turn, which is often the case. The software performs a correction to the errors arising from the turning of the mirror. In the realized instrument the allowed maximum angle of rotation of the mirror is ±5°, measuring range of the amplitude is 5 micron to 1 mm, measuring range of the frequency is 1 Hz to 5×104 Hz depending on the amplitude. © 1997 American Institute of Physics.

Open Access: Yes

DOI: 10.1063/1.1147888

The impact of migration of highly skilled workers on the country’s competitiveness and economic growth

Laszlo Vasa Yuriy Bilan Halyna Mishchuk Olena Oliinyk Oleksandr Akimov

Publication Name: Montenegrin Journal of Economics

Publication Date: 2021-01-01

Volume: 17

Issue: 3

Page Range: 7-19

Description:

The links between the migration of highly skilled workers and economic growth (in terms of GNI per capita) and the competitiveness of countries have been studied. The study is based on statistics from developed countries and using correlation-regression analysis and modelling, as well as cluster analysis using the package of processing and analysis of statistical information STATISTICA. The analysis found that the immigration of workers with higher education has a significant impact on strengthening the competitiveness and economic development of countries – this is confirmed by the impact of talent migration, which is assessed by the values of case studies (‘The Human Flight and Brain Drain’ sub-index Fragile States Index and ‘Brain gain’ sub-index’ in the Global Talent Competitiveness Index and ‘Highly educated workers’ sub-index in the OECD indicators of talent attractiveness). Their impact on macroeconomic indicators is higher compared to the links with social development indicators. Of course, this does not mean that such links should not be seen as important in public economic development management, as they illustrate the level of efficiency achieved in creating favourable conditions for realizing the potential of highly skilled workers, including pull-factors for their immigration. But in the macroeconomic management of a competitive economy, according to our research, actions aimed at attracting highly skilled migrants have the most significant and obvious impact. Other links can be taken into account and used in modelling for the development of institutional support for proactive migration policy for highly qualified workers.

Open Access: Yes

DOI: 10.14254/1800-5845/2021.17-3.1

Microalgal and cyanobacterial biostimulants used in wheat and maize production

I. Gergely G. Takács Vince Ördög Wendy A. Stirk Johannes van Staden

Publication Name: Biostimulants for Improving Reproductive Growth and Crop Yield

Publication Date: 2025-01-01

Volume: Unknown

Issue: Unknown

Page Range: 169-218

Description:

Wheat and maize are staple cereals that are each cultivated on about 200 million hectares globally. Microalgae and cyanobacteria have potential to be developed as biostimulants for wheat and maize production. This review focuses on biostimulating effects of various microalgae and cyanobacteria on seed priming, soil and foliar treatments applied in pot experiments and field trials. Two case studies on wheat and maize field trials are included. Seed priming with selected microalgal extracts is a promising method to promote plant growth but still needs validation in field trials. Soil biofertilizers based on living N2-fixing cyanobacteria (algalization) applied alone or in combination with plant growth promoting rhizobacteria modulate soil microbial composition and enhance nutrient uptake. However, this requires application of tens or hundreds kg/ha biomass to substitute for N-fertilizers so is not yet an economically viable option. The case studies indicated that a single foliar treatment of wheat at tillering and maize at the V6 growth stage with Chlorella vulgaris or Tetracystis sp. suspensions (0.1–1g DW/L applied at 400L/ha) increased grain yield, grain protein content and improve stress tolerance. These results indicated that certain microalgae could be effective biostimulants. However, producing sufficient microalgae biomass on a commercial scale is still a challenge. Monoalgal mass production in closed photobioreactors is expensive. A promising approach is the cultivation of mixed algal cultures in nutrient rich wastewater using open raceway reactors.

Open Access: Yes

DOI: 10.1016/B978-0-443-13207-0.00011-1

Adopting RFID in supply chains

Tamás Hartványi Lajos Tóth P. Németh

Publication Name: 2006 IEEE International Conference on Mechatronics Icm

Publication Date: 2006-12-01

Volume: Unknown

Issue: Unknown

Page Range: 263-266

Description:

Within the framework Interreg IIIC REGINS (Regional standardized Interfaces for a better integration of regional SMEs in the European Economy - http://www.regins.org) the Department of Logistics and Forwarding at the Széchenyi István University in Gyor, Hungary started a project with the title "Promotion of RFId (Radio Frequency Identification)". The project started in June 2005, and ended in May 2006. Our partners are situated in Upper Austria, Stuttgart Region, and Lombardy Region. Our project screens the state of the art and the ongoing development of RFId technology and processes. Special focus is on the needs of SMEs. This paper is the first in a series of publications regarding this topic, screening the state-of-the-art of RFId systems and the challanges and possibilities of the introduction to various supply chains. © 2006 IEEE.

Open Access: Yes

DOI: 10.1109/ICMECH.2006.252535

Hygrothermal behavior of ultralightweight polystyrene concrete

Máté Orosz Balázs Nagy Elek Tóth

Publication Name: Pollack Periodica

Publication Date: 2017-08-01

Volume: 12

Issue: 2

Page Range: 53-66

Description:

The aim of the paper is to investigate the hygrothermal properties of a newly developed ultra-lightweight polystyrene concrete, based on laboratory measurements. It describes the measuring process of thermal conductivities, and determines the declared thermal conductivity. The temperature and moisture conversion coefficients are determined, and new approximate functions are introduced. The paper describes the sorption and desorption isotherms, and gives polynomial approximate functions. The paper also investigates the temperature dependency of sorption curves. It determines the water absorption coefficient and the free water saturation. Furthermore, it describes the measuring process of the water vapor permeability. The water vapor resistance factor and water vapor diffusion-equivalent air layer thickness are calculated.

Open Access: Yes

DOI: 10.1556/606.2017.12.2.5

Potentials and challenges of augmented reality smart glasses in logistics and supply chain management: a systematic literature review

Horst Treiblmaier John G. Keogh Abderahman Rejeb G. Keong Leong

Publication Name: International Journal of Production Research

Publication Date: 2021-01-01

Volume: 59

Issue: 12

Page Range: 3747-3776

Description:

This study investigates the potentials and challenges of applying augmented reality (AR) smart glasses in logistics and supply chain management (SCM). A systematic literature review on AR smart glasses was conducted to provide a comprehensive synthesis of what has been published in the literature to capture the dynamics surrounding this technology and identify areas deserving of further academic attention. To summarise the latest developments in this field, eighty-two (82) publications were selected and thoroughly analysed. In terms of research findings, four main clusters of potential benefits were identified: visualisation, interaction, user convenience, and navigation. In contrast, the challenges posed by smart glasses in the logistics field were clustered around technical, organisational, and ergonomic considerations. The accumulation of knowledge and actionable insights in this study will benefit both academics and practitioners interested in this emerging wearable technology segment. As the first attempt to explore the importance of smart glasses in logistics and SCM activities, this study offers significant contributions to the literature by codifying extant knowledge on AR smart glasses and setting forth an agenda for future research.

Open Access: Yes

DOI: 10.1080/00207543.2021.1876942

Impact of measurement and test parameters on the rpm-sweep test accuracy of e-motors

Balázs Vehovszky Zoltán Gazdagh D. Acs

Publication Name: 54th International Congress and Exposition on Noise Control Engineering Internoise 2025

Publication Date: 2025-01-01

Volume: 4

Issue: Unknown

Page Range: 70-77

Description:

The electrification of the vehicle industry has led to a significant increase in the demand for innovative vibration testing. The RPM-sweep experiments of e-motors and e-drives are considered to be fundamental, as they provide valuable vibration and durability data for further analysis. The aim is to model the behavior of rotating-dynamic systems throughout their life cycles. However, inaccuracies in the definition of measurement and test parameters can result inaccurate transfer functions, ultimately reducing the accuracy and reliability of the test results. This paper focuses on two critical parameters: frequency resolution and RPM-sweep rate. Both of these parameters have a significant impact on the amplitude response of the system and can lead to substantial distortion of the FRFs. In this study, we characterize these distortions and propose a method to ensure that the error introduced by the chosen frequency resolution and RPM-sweep rate remains below a predefined threshold value. In addition to the theoretical derivation, we demonstrate the application of this method using real measurement data. This research aims to address the challenges associated with NVH testing in the context of the electrification of the vehicle industry, providing a valuable contribution to the development of more accurate and reliable testing methodologies.

Open Access: Yes

DOI: 10.3397/IN_2025_1062472

Resilience-oriented seismic retrofit of heritage masonry minarets using hybrid base isolation and supplemental damping

Said Elias Mustafa Ergun Zeliha Tonyali Adnan Kiral

Publication Name: Structures

Publication Date: 2026-01-01

Volume: 83

Issue: Unknown

Page Range: Unknown

Description:

Historic masonry mosques represent a highly vulnerable class of cultural heritage structures whose seismic fragility stems from their complex geometries, heterogeneous material composition, and rigid load-transfer mechanisms. This study presents a resilience-oriented seismic performance improvement of the historic masonry minaret of the Bayburt Grand Mosque, a structure with limited lateral deformation capacity that challenges the applicability of conventional strengthening measures. To address this limitation, a hybrid retrofitting strategy is introduced, integrating lead rubber bearings (LRBs) with supplemental viscous dampers (VDs) at the foundation level. This combined system—implemented for the first time in a historic masonry minaret—aims to enhance energy dissipation and displacement control through a minimally invasive and architecturally compatible approach. Finite element analyses (FEA), coupled with MATLAB-supported optimization routines, were used to calibrate isolator stiffness and damper coefficients. Three configurations were evaluated: fixed-base, LRB-isolated, and hybrid LRB–VD systems. Nonlinear time-history analyses (NTHAs) using the 1992 Erzincan (Otlukbeli) earthquake record quantified displacements, stress–strain responses, and damage progression. Results show that while base isolation mitigates seismic demand, it remains insufficient under restricted deformation capacity. The proposed hybrid system reduces peak horizontal displacements from 22 cm to 12 cm, limits drift ratios below 0.17 %, and lowers maximum tensile stresses from 4.890 MPa to 0.490 MPa—well below the masonry tensile strength of 0.880 MPa. Two iterative analytical design methodologies are additionally introduced to derive effective isolator stiffness and viscous damping coefficients, enabling systematic integration into resilience-focused evaluation frameworks. Overall, the study advances reliability-based, conservation-compatible retrofitting practices for historic masonry minarets and supports sustainable strategies for seismic risk mitigation.

Open Access: Yes

DOI: 10.1016/j.istruc.2025.110893