Search Everything

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

Publications - 6674

Szekszárd-Palánk and the postglacial recolonization of the Pannonian Basin

György Lengyel Tibor Marton Annamária Bárány Julia Blumenröther Kristóf István Szegedi Gergely Páll-Barna Endre Dobos

Publication Name: Dissertationes Archaeologicae Ex Instituto Archaeologico Universitatis De Rolando Eotvos Nominatae

Publication Date: 2025-01-01

Volume: 3

Issue: 13

Page Range: 321-351

Description:

Szekszárd-Palánk, located in South Transdanubia (Hungary), was discovered in the late 1950s and has yielded several hundred archaeological finds, including lithics and faunal remains. Initially, the site was regarded as ‘the latest Palaeolithic’ site in Hungary; later, it was reclassified as an Early Mesolithic industry bridging the Palaeolithic–Mesolithic transition. More recently, the site was proposed to be evidence for the continuity of Epigravettian hunter-gatherers from the Late Glacial to the Early Holocene. However, recent findings regarding the Late Epigravettian in the Pannonian Basin suggest that these populations vanished with the onset of Greenland Interstadial 1. To address this discrepancy, the authors reassessed the lithic assemblage and archaeozoological remains, obtained new radiocarbon dates, and conducted a new excavation to re-evaluate the stratigraphy and geomorphological processes of the site. Our new absolute dates place the site firmly between 11.6–10.4 ka cal BP, and techno-typo-logical analysis attributes it to the Early Holocene Final Epigravettian. These results indicate that hunter-gatherers largely abandoned the Pannonian Basin during Greenland Interstadial 1 and Greenland Stadial 1. This population vacuum ended at the onset of the Preboreal with the arrival of hunter-gatherers from the Balkans or Adriatic coastlines. The repopulation process appears to have been influenced by palaeoecological factors, with the establishment of the pioneering Early Holocene Final Epigravettian settlement in South Transdanubia coinciding with global sea-level rise Meltwater Pulse Event 1B.

Open Access: Yes

DOI: 10.17204/dissarch.2025.321

Modification of Concrete Railway Sleeper Mix Design, Using a Hybrid Application of Steel Fibers

Guoqing Jing Farshad Astaraki Mohammad Siahkouhi R. M. Movahedi Sashka Uuganbayar Jun Wang

Publication Name: Acta Polytechnica Hungarica

Publication Date: 2022-01-01

Volume: 19

Issue: 3

Page Range: 119-130

Description:

Concrete railway sleepers have been used for years without an update in production and design, to be compatible with demands for increasing train axle loads and speed. In the current research, concrete railway admixture is modified with consuming (0.5% straight-1.5% hooked), (1.5% straight-0.5% hooked) and (1% straight-1% hooked) steel fibers combinations. Three main mechanical experiments as compressive, flexural and splitting tensile strengths and fresh mortar “flowability” were performed. Results showed that the hybrid of 1% straight and 1% hooked steel fibers shows the optimal performance among other hybrid combinations. This hybrid admixture efficiently improves the compressive, flexural and splitting tensile strengths of the concrete railway sleeper mix design.

Open Access: Yes

DOI: DOI not available

Function approximation capability of a novel fuzzy flip-flop based Neural Network

László Gál Rita Lovassy László T. Kóczy

Publication Name: Proceedings of the International Joint Conference on Neural Networks

Publication Date: 2009-11-18

Volume: Unknown

Issue: Unknown

Page Range: 1900-1907

Description:

The function approximation capability of various connectionist systems has been one of the most interesting problems. A method for constructing Multilayer Perceptron Neural Networks (MLP NN) with the aid of fuzzy operations based flip-flops able to approximate single and multiple variable functions is proposed. This paper introduces the concept of fuzzy flip-flop based neural network, particularly by deploying three types of fuzzy flip-flops as neurons. A comparative study of feedbacked fuzzy J-K and two kinds of fuzzy D flip-flops used as neurons, based on fuzzy algebraic, Yager, Dombi, Hamacher and Frank operations is given. Simulation results are presented for several test functions. © 2009 IEEE.

Open Access: Yes

DOI: 10.1109/IJCNN.2009.5178849

Artificial aging experiments of neat and contaminated engine oil samples

I. Zsoldos A. L. Nagy J. Rohde-Brandenburger

Publication Name: Lubricants

Publication Date: 2021-06-01

Volume: 9

Issue: 6

Page Range: Unknown

Description:

This study highlights how the results from an artificial engine oil aging method compare to used engine oil samples collected from a vehicle fleet. Additionally, this paper presents the effect of contaminating the oil during aging with synthetic fuel alternatives on the physical and chemical properties of artificially aged engine oil samples. A laboratory-scale artificial thermo-oxidative aging experiment was conducted on multiple samples of commercially available formulated fully-synthetic SAE 0W-30 engine oil. The goal of the experiment was to establish the validity of the artificially aged samples as well as the validity of the underlying process in reproducibly fabricating small batches of aged engine oil with comparable chemical and physical properties to real-life used oils. Eight samples were subjected to distinct load cases (temperature, air flow rate, sample volume and aging time). Six additional samples were subjected to an intermediate load case, with five of them contaminated with selected conventional fuels and novel automotive fuel candidates. Conventional oil analysis was conducted on each sample to determine oxidation, residual additive content, kinematic viscosity and total base number. Additionally, analysis results were compared to in-use engine oil samples through PCA. The resulting oil condition after aging is in accordance with independently published results in terms of zinc dialkyldithiophosphate content and kinematic viscosity. Contaminated aging with OME3-5 resulted in a drop in antioxidant content and elevated kinematic viscosity. Based on the comparison with in-use samples, artificial aging of 200 mL engine oil at 180◦ C with 1 L/min air flow for 96 h can produce similar oil conditions as mixed vehicle use for 7000 km.

Open Access: Yes

DOI: 10.3390/lubricants9060063

Combined asymmetric influences of renewable energy consumption and categorical economic policy uncertainty on economic growth in Japan: New insights from QQR and KRLS approaches

Gagan Deep Sharma Magdalena Radulescu D. Balsalobre-Lorente Sanjeet Singh M. Usman

Publication Name: Environment Development and Sustainability

Publication Date: 2025-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

This study focuses on the asymmetric relationship between categorical economic policy uncertainty indices and Japanese economic growth and renewable energy consumption from January 1987 to December 2021. Economic policy uncertainty has multidimensional effects on the global economy. To address non-linearity, Kernel-Based Regularized Least Squares (KRLS) and quantile-on-quantile regression (QQR) are applied to examine the impact of fiscal policy uncertainty, monetary policy uncertainty, trade policy uncertainty, and exchange rate uncertainty on economic growth and renewable energy consumption. The average KRLS results indicate that fiscal and exchange rate policy uncertainty negatively influence economic growth, while uncertainty in monetary and trade policy has a favorable impact in the long-term. A significant decrease in renewable energy consumption is attributed to increasing fiscal and trade policy uncertainty indices, whereas monetary and exchange rate policy uncertainty contributes to the enhancement of renewable energy consumption. The QQR results align with the KRLS findings, with a slight variation for monetary policy uncertainty, which was found to be negligible for economic growth across all quartiles according to QQR approach. Given the recent increase in economic policy uncertainty due to the COVID-19 pandemic and the Ukrainian conflict, our findings support several crucial policy recommendations for promoting economic development and renewable energy consumption in Japan.

Open Access: Yes

DOI: 10.1007/s10668-025-06156-w

Modeling laterally loaded piles

János Szép

Publication Name: Pollack Periodica

Publication Date: 2013-08-01

Volume: 8

Issue: 2

Page Range: 117-129

Description:

Single row pile groups are gaining popularity as foundation system for both buildings and bridges. They are a reasonable and economical solutions for structures with low vertical loads e.g. bridge abutments. The lateral resistance of a pile group is the result of contact pressure between the individual pile shafts and the soil. When designing this kind of structure, the estimation of displacements and bending moments is the main focus of the calculation. In most cases single piles are modeled by assuming a Winkler material. For their calculations, designers typically employ one of the commonly-used structural FEM codes (e.g. AxisVM, Fem-Design). On the other hand, advanced, truly 3D FEM packages (like MIDAS GTS, Plaxis 3D) are available, allowing for realistic modeling of the soil environment and soil-structure interaction. As an intermediate solution, packages based on traditional approaches are also available (GEO5, CGU). In this paper, results obtained using three different calculation methods and packages are compared.

Open Access: Yes

DOI: 10.1556/Pollack.8.2013.2.13

The impact of financial development and economic complexity on energy and carbon intensity: evidence of the top 10 complex countries

Irum Shahzadi Herick Fernando Moralles Diogo Ferraz Buhari Doğan Irum Shahzadi

Publication Name: Energy Sources Part B Economics Planning and Policy

Publication Date: 2025-01-01

Volume: 20

Issue: 1

Page Range: Unknown

Description:

This paper explores the impact of economic complexity and financial development on energy efficiency through two indicators: energy intensity and carbon intensity, within the top 10 complex economies. Other control variables, such as economic growth, urbanization, and human capital, are also included in the models. Random and fixed-effects estimators with heteroskedasticity-consistent standard errors were used. Clustered random and fixed-effects estimators were considered to handle within-group (cluster) dependence. The study utilized the Driscoll-Kraay (DK) method to address non-spherical disturbances and ensure consistent standard errors and robustness against dependence. Feasible Generalized Least Squares (FGLS) considered entity-specific autocorrelation, and System Generalized Method of Moments (Sys-GMM) accommodated unobserved panel-level effects, were also employed. Our findings reveal that economic complexity is crucial in reducing carbon and energy intensity, highlighting the significance of fostering technological sectors to diversify and sophisticate the productive structure. However, the influence of financial development on these intensity measures remains ambiguous and necessitates further exploration. We propose policy implications aimed at boosting technological sectors, facilitating a green transition in the economy, and advancing the adoption of renewable energy technologies.

Open Access: Yes

DOI: 10.1080/15567249.2025.2516447

Verilog-A Implementation of a Nonlinear Permanent Magnet Synchronous Machine Model for Sensorless Polarity Detection

Istvan Szalay Ferenc Péter Speiser Denes Fodor

Publication Name: Edpe 2025 37th International Conference on Electrical Drives and Power Electronics and 12th Joint Croatia Slovakia Conference

Publication Date: 2025-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

In this paper, we present the implementation process of a novel extended PMSM model in Verilog-A. The extended PMSM model is based on a quadratic flux-current function that describes the machine's rotor position-dependent and polaritydependent characteristics, enabling the development of signal injection-based sensorless polarity detection algorithms. The Verilog-A module was compiled using OpenVAF, simulated with Ngspice, and integrated via the Qucs-S frontend. Validation was carried out through comparison of simulations and corresponding measurements of non-modulated square-wave and modulated sinusoidal signal injection, two commonly used carrier signals in sensorless control. Simulation results showed good agreement with measurements. The implemented PMSM model is open source. The code and related data are available on GitHub.

Open Access: Yes

DOI: 10.1109/EDPE66853.2025.11224147

Auditory representations of a graphical user interface for a better human-computer interaction

György Wersényi

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

Publication Date: 2010-12-01

Volume: 5954 LNCS

Issue: Unknown

Page Range: 80-102

Description:

As part of a project to improve human computer interaction mostly for blind users, a survey with 50 blind and 100 sighted users included a questionnaire about their user habits during everyday use of personal computers. Based on their answers, the most important functions and applications were selected and results of the two groups were compared. Special user habits and needs of blind users are described. The second part of the investigation included collecting of auditory representations (auditory icons, spearcons etc.), mapping with visual information and evaluation with the target groups. Furthermore, a new design method for auditory events and class was introduced, called "auditory emoticons". These use non-verbal human voice samples to represent additional emotional content. Blind and sighted users evaluated different auditory representations for the selected events, including spearcons for different languages. Auditory icons using environmental, familiar sounds as well emoticons are received very well, whilst spearcons seem to be redundant except menu navigation for blind users. © 2010 Springer-Verlag Berlin Heidelberg.

Open Access: Yes

DOI: 10.1007/978-3-642-12439-6_5