Search in Publications

Found 6427 publications

Analysis of a vector hysteresis measurement system

Miklós Kuczmann

Publication Name: Journal of Optoelectronics and Advanced Materials

Publication Date: 2008-01-01

Volume: 10

Issue: 7

Page Range: 1823-1827

Description:

The paper deals with the numerical analysis of a vector hysteresis measurement system which is now under construction. The measurement set up consists of an induction motor which rotor has been removed, and its windings have been replaced to a special two phase one which can generate homogeneous magnetic field inside the motor. A round shaped specimen can be inserted into the arrangement. The two orthogonal components of the magnetic field intensity and of the magnetic flux density vectors can be measured by H-coils and B-coils, respectively. The Finite Element Method (FEM) with the T, Φ - ΦD potential formulation has been applied in the simulations. The vector hysteresis property of the specimen has been approximated by the vector Preisach model, finally the nonlinear problem has been solved by the convergent fixed point technique. The aim of the present work is to focus on the design aspects of this kind of measurement system.

Open Access: Yes

DOI: DOI not available

OLD AND NEW CHALLENGES IN REGIONAL DEVELOPMENT – COMPARATIVE ANALYSIS OF EUROPEAN REGIONAL DEVELOPMENT POLICY APPROACHES TO IDENTIFYING BENEFICIARY REGIONS

Katalin Mezei Gábor Mayer

Publication Name: Deturope

Publication Date: 2025-01-01

Volume: 17

Issue: 3

Page Range: 50-74

Description:

Most European countries apply development policy solutions to help disadvantaged regions catch up and seek effective solutions for territorial cohesion. This endeavour has been strongly supported by the European Commission in both the 2013-2020 and 2021-27 programming periods and is likely to remain so in the period after 2028. This is an understandable and logical endeavour, as being 'left behind' in economic, social or geographical terms not only reinforces internal migration flows within the European Community and its Member States but also increases political discontent. A number of approaches have emerged in European countries to identify disadvantaged regions and address their problems. The differences stem partly from the different intervention intentions of individual countries and partly from their different spatial, state and public administration structures. Various development policy solutions have been devised to help disadvantaged regions catch up, taking these factors into account. In Hungary, development policy has placed greater emphasis on the catching up of regions and settlements lagging behind in terms of socio-economic development since the 1980s, but the importance of delimitation in development policy practice has increased since the country's accession to the EU, with the establishment of differentiated support resource allocation mechanisms and targeted support programmes. The methodology currently in use for designating beneficiary regions has been in place since 2014. The socioeconomic changes that have taken place since then have shifted the focus of both scientific and policy interest in recent years towards more location-specific regulatory mechanisms that measure development differences at a lower level and are more sensitive to functional links between settlements. To support efforts in the renewal of the Hungarian regional development toolkit, our study seeks to outline alternative options by analysing Italian and British development policy practices, in addition to presenting Hungarian beneficiary regions. The international examples examined, despite their limitations as presented in the study, provide examples of multi-level governance, development policies based on functional units, and methodologies for measuring development below the settlement level. Current legislation in Hungary allows for changes in this direction, but their incorporation into domestic practice is only possible after careful preparation.

Open Access: Yes

DOI: 10.32725/det.2025.019

Bioactivity assessment, micropollutant and nutrient removal ability of Tetradesmus obliquus cultivated outdoors in centrate from urban wastewater

Gergely Lakatos Tereza Černá Tomáš Grivalský Marta Barceló-Villalobos João Artur Câmara Manoel Karolína Ranglová Francisca Suárez Estrella Vince Ördög Jiří Masojídek

Publication Name: Journal of Applied Phycology

Publication Date: 2022-12-01

Volume: 34

Issue: 6

Page Range: 2955-2970

Description:

Nutrient and micropollutant removal, and bioactivity were studied in cultures of the green microalga Tetradesmus obliquus MACC-677 grown in centrate from municipal wastewater (WW). Two outdoor units, a thin-layer cascade (TLC) and a thin-layer raceway pond (TL-RWP), were tested for microalgal culturing in batch and semi-continuous regimes where their photosynthetic performance was monitored. The results revealed that the T. obliquus cultures grew well, showing a high specific growth rate µ of 0.31 day−1 and 0.25 day−1 when grown in WW in TLC and TL-RWP, respectively. The cultivation trials showed high nutrient removal efficiency for ammonium nitrogen (98.5%) as well as orthophosphate (89%), the most abundant forms of N and P occurring in municipal WW. The removal of selected pharmaceuticals and endocrine disruptors (e.g., ibuprofen, amitriptyline, bisphenol A, etc.) was also assessed. Ibuprofen was the most abundant micropollutant detected in the centrate, with concentrations up to 5000 ng L−1 and fast removal during the cultivation. The biomass produced in the centrate revealed antimicrobial activity against plant pathogens, including fungi, oomycota, and bacteria. These findings have shown that the culturing of T. obliquus can be considered a suitable way to contribute to a circular economy, to remove nutrients and micropollutants from municipal WW from which biomass extracts can be further used for plant protection in agriculture.

Open Access: Yes

DOI: 10.1007/s10811-022-02828-6

Combination of Simulation and Machine Learning to Mitigate Traffic Emissions

Ferenc Erdos Enas Elshebli

Publication Name: 2022 13th IEEE International Conference on Cognitive Infocommunications Coginfocom 2022

Publication Date: 2022-01-01

Volume: Unknown

Issue: Unknown

Page Range: 41-46

Description:

Nowadays, traffic congestion and air pollution in urban areas become huge challenges to transportation engineering. On the other hand, technologies have evolved, and simulation and artificial intelligence have become important tools to face these challenges. In this paper, a review of this research field is done, and a possible combination of simulation and machine learning to mitigate traffic emissions is proposed. The long-term goal of the research is to establish an effective emission mitigation model for some specific crossings.

Open Access: Yes

DOI: 10.1109/CogInfoCom55841.2022.10081682

Best approximation of OWA Olympic weights under predefined level of orness

Lucian Coroianu Istvan A. Harmati Robert Fuller

Publication Name: Fuzzy Sets and Systems

Publication Date: 2022-11-05

Volume: 448

Issue: Unknown

Page Range: 127-144

Description:

An ideal type of OWA aggregation operator is the one constructed on the so-called Olympic weights. The orness of this operator is 1/2. Therefore, sometimes we need a trade-off between the desire of having an OWA aggregation operator with weights as close as possible to the Olympic ones and the desire of having a predefined level of orness. In this paper, we choose these optimal weights by minimizing the Euclidean distance to the Olympic weights vector under the constraint of preserving a given level of orness. First, in the case n=4, we propose an iterative algorithm where the optimal solution is given for all possible values of the orness, values that are grouped along a partition of the unit interval. This iterative algorithm will inspire us to deduce the optimal weights in the general case. Consequently, we will obtain the analytical solution of the optimal weights as a function depending on the orness level.

Open Access: Yes

DOI: 10.1016/j.fss.2022.07.009

Effect of Sleeper-Ballast Particle Contact on Lateral Resistance of Concrete Sleepers in Ballasted Railway Tracks

Majid Movahedi Rad Jafar Chalabii Ebrahim Hadizadeh Raisi Reza Esfandiari Mehni

Publication Name: Materials

Publication Date: 2022-11-01

Volume: 15

Issue: 21

Page Range: Unknown

Description:

Although a sleeper makes a great contribution to the lateral resistance of ballasted tracks, in this regard, limited studies have been carried out on the effect of its contact surface with ballast aggregates. The current paper is dedicated to evaluating the effect of sleeper shape on the lateral resistance of ballasted track through discrete element modelling (DEM). For this purpose, firstly, a DEM model was validated based on the experimental results. Then, a sensitivity analysis was undertaken on the effect of the different contact areas that a standard concrete sleeper faces with the crib, shoulder and underlying ballast aggregates on lateral resistance of a single sleeper. As the main result of the current study, a high accurate regression equation for constant weight 319.2 kg and constant density 2500 kg/m3 of the sleepers was fitted between different sleeper contact areas and the maximum lateral resistance of a concrete sleeper for 3.5 mm lateral displacement in ballasted railway tracks. The obtained results showed that the effect of the sleeper’s head area compared to the underlying area of the sleeper and the head area of the sleeper compared to the sleeper’s side area in terms of lateral resistance are 8.2 times and 14.5 times more, respectively.

Open Access: Yes

DOI: 10.3390/ma15217508

Fast meshless techniques based on the regularized method of fundamental solutions

Csaba Gáspár

Publication Name: Lecture Notes in Computer Science Including Subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics

Publication Date: 2017-01-01

Volume: 10187 LNCS

Issue: Unknown

Page Range: 334-341

Description:

A regularized method of fundamental solutions is presented. The method can handle Neumann and mixed boundary conditions as well without using a desingularization technique. Instead, the approach combines the regularized method of fundamental solutions with traditional finite difference techniques based on some inner collocation points located in the vicinity of the boundary collocation points. Nevertheless, the resulting method remains meshless. The method avoids the problem of singularity and can be embedded in a natural multi-level context. The method is illustrated via a numerical example.

Open Access: Yes

DOI: 10.1007/978-3-319-57099-0_36

Digital Transformation in Taiwan’s Insurance Industries for MABAC Technology Based on Circular Modified Fuzzy Choquet Frank Network Data Envelopment Analysis

Dragan Pamucar Zeeshan Ali

Publication Name: International Journal of Analysis and Applications

Publication Date: 2025-01-01

Volume: 23

Issue: Unknown

Page Range: Unknown

Description:

Fuzzy set theory has significant and dominant applications in Taiwan’s insurance industry, especially in fields involving decision-making, uncertainty, and risk assessment. Providing the complexity and problems in assessing factors, for instance, natural disaster risks, customer creditworthiness, or health conditions, traditional binary logic often falls short. Taiwanese insurers have adopted fuzzy logic systems to enhance fraud detection, premium pricing, and privilege evaluations by catching the indistinctness characteristic in human ruling and imperfect data. The Taiwan insurance industry is a dynamic and spirited module of the commercial sector, contributing meaningfully to risk management and economic stability. For this, we study to propose an assessment of the proficiency of insurance enterprises using Network Data Envelopment Analysis. Toward this end, the frank operational laws for circular Pythagorean fuzzy (CPF) uncertainty are applied. Moreover, the CPF Choquet Frank averaging (CPFCFA) operator and CPF Choquet Frank geometric (CPFCFG) operator with three dominant properties for each operator have been studied. The study deliberates the multi-attributive border approximation area comparison (MABAC) model and verifies it with the help of numerical examples. This study enhances the industry’s efficiency to offer adapted insurance products and handle risks precisely, aligning with Taiwan’s push toward intelligent financial services and digital transformation. In the following, we establish the decision-making performance for assessing the proficiency of insurance enterprises using the network data envelopment analysis (NDEA) technique. Finally, we examine the ranking values of offered representations to compare them with the ranking values of prevailing models to show the capability and efficacy of the originated approaches.

Open Access: Yes

DOI: 10.28924/2291-8639-23-2025-245

Development of a multibody model for go-karts considering frame flexibility

Ambrus Zelei Krisztián Horváth

Publication Name: Pollack Periodica

Publication Date: 2024-10-16

Volume: 19

Issue: 3

Page Range: 66-73

Description:

This study focuses on the optimization dynamics of racing go-karts, which is heavily influenced by the frame's stiffness. Lacking suspensions and differentials, go-karts rely on the frame stiffness for wheel balancing and skid prevention by lifting the inner rear wheel during turns. Utilizing a rigid-flexible model in MSC Software ADAMS View, validated by frame deformation measurements, this research integrates finite element analysis with multibody techniques. The model, leverages computer aided design files for frame geometry and employs finite element analysis for frame validation. It facilitates evaluating go-kart dynamics through simulations, aiding in maneuver testing and design optimization. This approach provides a comprehensive framework for advancing go-kart designs.

Open Access: Yes

DOI: 10.1556/606.2024.01050