Search Everything

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

Publications - 6374

Context recognition in mobile robots cooperation using fuzzy signature

Claudiu Radu Pozna Áron Ballagi Ĺaszĺo T. Ḱoczy

Publication Name: International Conference on Theoretical and Mathematical Foundations of Computer Science 2010 Tmfcs 2010

Publication Date: 2010-12-01

Volume: Unknown

Issue: Unknown

Page Range: 110-115

Description:

Robots cooperation means also to define the commune task. In order to understand their cooperation the robots must have complete knowledge about all possible states of the work or to understand the context by extract useful information from observation. Present paper focus on the second possibility. We propose a strategy of information extraction and context understanding based on an original data structure, the fuzzy signature and on a priori knowledge, the robot codebook. The paper starts by presenting the concept of the fuzzy signature and exemplify the idea of cooperation by context understanding.

Open Access: Yes

DOI: DOI not available

Development of comparative investigation method for timing chain wear analysis using oscillating tribometer

Cs Tóth-Nagy Rajmund Kuti J. Rohde-Brandenburger L. Paulovics

Publication Name: Acta Technica Jaurinensis

Publication Date: 2021-11-24

Volume: 14

Issue: 4

Page Range: 406-423

Description:

This paper presents the development of a test procedure to investigate timing chain components under abrasive stress on a tribometer. Engine developers use cost and time expensive engine dynamometer tests to investigate timing chain life expectancy under different conditions. Tribometer tests are fast and cost effective, but these use standardized specimen material and geometry that greatly differ from the original tribological system of the timing chain. Manufacturing specimens from the original chain material using the original technology is complicated; surface quality and hardness properties cannot be guaranteed. The aim of research was to develop a test method for rapid and cost-effective comparison of engine lubricants, timing chain materials or coatings, as well as to assess the wear resistance of the chain to contaminants. Various uncontaminated and carbon black blended lubricants were compared using standard-based ball-on-disc tribometer tests to tribometer tests using actual timing chain components (bush-on-pin test) of a Diesel engine. Lubricants were ranked in terms of coefficient of friction and wear. Results showed that bush-on-pin tests were comparably suitable for testing lubricants when evaluated against standard ball-on-disc tribometer tests.

Open Access: Yes

DOI: 10.14513/actatechjaur.00620

Kornai’s “main line of causality”: The case of socialist Albania and SFR Yugoslavia, with a special focus on their banking sectors’ ownership structure

Eszter Kazinczy

Publication Name: Acta Oeconomica

Publication Date: 2023-11-03

Volume: 73

Issue: Unknown

Page Range: 173-190

Description:

Based on the structure of János Kornai’s ‘main line of causality’, two unique country cases are compared within the former European socialist bloc: Albania and the Socialist Federal Republic of Yugoslavia. The research provides a comparative analysis with an overview of the two countries’ development between World War II and the fall of the socialist regimes. Special attention is paid to the period following the 1970s as the underlying reforms had been implemented in Yugoslavia by then, leading to fundamentally different socialist prototypes. Regarding the differences, the analysis also gives an insight into the structure of the two respective banking systems. Kornai’s ‘main line of causality’ provides the framework for the current research, supplemented by the respective literature. The analysis concludes that despite the fact that all blocks of the causality line differed in the two systems, similar challenges had to be addressed during the transition period. Furthermore, Albania and the successor states of Yugoslavia reflected a range of common characteristics, which implies the relevance of path dependence.

Open Access: Yes

DOI: 10.1556/032.2023.00041

Quantifying Capacity Reductions from Pedestrian Activity at Unsignalized Crosswalks: A Queuing-Based Assessment Across 24 Hungarian Sites

Emese Makó Souvathone Phetoudom

Publication Name: Lecture Notes in Networks and Systems

Publication Date: 2026-01-01

Volume: 1768 LNNS

Issue: Unknown

Page Range: 127-135

Description:

This study applies an approximate queuing framework to analyze pedestrian flow at 24 crosswalks in Hungary. Data on pedestrian and vehicle volumes, crosswalk dimensions, and vehicle speeds were collected. Key parameters such as pedestrian arrival rates, crossing times, and waiting times were estimated using simplified queuing assumptions. The analysis reveals that pedestrian flow and occupancy significantly impact crosswalk capacity, with reductions ranging from 3% to 50%, particularly at locations with high pedestrian volumes and longer crossing durations. Findings highlight the importance of pedestrian flow characteristics in capacity estimation and demonstrate the practicality of this framework for assessing crosswalk performance. This study applies queuing-based flow analysis across multiple real-world sites using low-data, accessible methods. The results provide valuable insights for urban planners seeking to optimize pedestrian safety and improve crosswalk efficiency, emphasizing the need for targeted interventions like signal timing adjustments and crosswalk redesigns. This approach offers a cost-effective tool for preliminary capacity analysis, supporting informed decision-making in urban transportation planning and pedestrian management.

Open Access: Yes

DOI: 10.1007/978-3-032-13898-9_15

ENOUGH FROM THE LAMELLA

Andor Wesselényi-Garay

Publication Name: Metszet

Publication Date: 2024-01-01

Volume: 15

Issue: 3

Page Range: 34-41

Description:

I think there is not a Hungarian architect who has not asked themself at least once what Hungarian architecture is. Therefore, what steps can be taken when invited to redevelop the external appearance of an offi- ce in the centre of Pest. How does one achieve an architecture that in- forms a Hungarian identity? Does the choice of employing external lamella wall systems answer this is terms of aesthetic or even contem- porary technological implementation? Or is the lamella something that should be passed over as it reduces a building to being an identity/na- tionality free shell? The intention is acceptable, but at what cost?

Open Access: Yes

DOI: 10.33268/Met.2024.3.4

Population genetic features of calving interval of the Limousin beef cattle breed in Hungary

Szabolcs Bene Eszter Szabó Márton Szűcs Judit Márton Ferenc Szabó Péter J. Polgár

Publication Name: Acta Veterinaria Hungarica

Publication Date: 2022-07-06

Volume: 70

Issue: 2

Page Range: 113-120

Description:

Variance, covariance components, heritability, breeding values (BV) and genetic trends in calving interval (CI) of the Limousin population in Hungary were evaluated. A total of 3,008 CI data of 779 cows from three herds in 1996-2016 were processed. For influencing effects GLM method, for population genetic parameters and BV estimation BLUP animal model, for trend analyses linear regression was applied. The average CI obtained was 378.8 ± 3.1 days. The variance distribution components of the phenotype were as follow: age of cow at calving 34.30%, season of calving 26.09%, year of calving 23.00%, sire 7.45%, herd 3.23%, sex of calf 0.33% and type of calving 0.30%. The heritability of CI proved to be low (h2 d = 0.04 ± 0.02 and 0.03 ± 0.02; h2 m = 0.01 ± 0.02). The repeatability was low (R = 0.03 ± 0.02). Based on the phenotypic trend calculation, the CI of cows decreased by an average of 0.60 days per year (R 2 = 0.19; P < 0.05). In case of genetic trend calculation, the average BV of sires in CI increased 0.07 and 0.17 days per year (R 2 = 0.23 and 0.27; P < 0.05).

Open Access: Yes

DOI: 10.1556/004.2022.00008

Sensitivity analysis of tooth microgeometric modifications on vibroacoustic behaviour in helical gears with harmonically distributed variations

Ambrus Zelei Krisztián Horváth

Publication Name: Journal of Physics Conference Series

Publication Date: 2026-01-01

Volume: 3190

Issue: 1

Page Range: Unknown

Description:

The virtual acoustic testing of gear drives has gained growing importance. Fundamentally, the transmission error (TE) is predicted, since it directly affects the vibration and noise characteristics. In this study, the effect of the harmonically distributed tooth microgeometric variations on the TE is investigated via elastic multibody simulations of a helical gear pair. The sensitivity analysis focused on the tip relief, the root relief and the barrelling. The model considered different degrees of linear-, quadratic- and cubic-harmonically distributed variations. The results showed that barrelling with quadratic harmonic micro-geometry had the most significant effect on TE. In addition, if harmonic distributions accidentally coincide in the pairing of the gears, the TE is significantly amplified, leading to a pronounced excitation of the system dynamics.

Open Access: Yes

DOI: 10.1088/1742-6596/3190/1/012005

Investigation of the Applicability of Y2O3–ZrO2 Spherical Nanoparticles as Tribological Lubricant Additives

Máté Zs Leskó D. Tóth I. Szabó Hajnalka Hargitai

Publication Name: Lubricants

Publication Date: 2022-07-01

Volume: 10

Issue: 7

Page Range: Unknown

Description:

Long-term environmental goals will motivate the automotive industry, component suppliers, and lubricating oil developers to reduce the friction of their tribosystems to improve overall efficiency and wear for increased component lifetime. Nanoscale ceramic particles have been shown to form a protective layer on components’ surface that reduces wear rate with its high hardness and chemical resistance. One such ceramic is yttria (Y2O3), which has an excellent anti-wear effect, but due to its rarity it would be extremely expensive to produce engine lubricant made from it. Therefore, part of the yttria is replaced by zirconia (ZrO2) with similar physical properties. The study presents the result of the experimental tribological investigation of nanosized yttria–zirconia ceramic mixture as an engine lubricant additive. Yttria-stabilized zirconia (YSZ) nanoparticle was used as the basis for the ratio of the ceramic mixture, so that the weight ratio of yttria–zirconia in the resulting mixture was determined to be 11:69. After the evaluation of the ball-on-disc tribological measurements, it can be stated that the optimal concentration was 0.4 wt%, which reduced the wear diameter by 30% and the wear volume by 90% at the same coefficient of friction. High-resolution SEM analysis showed a significant amount of zirconia on the surface, but no yttria was found.

Open Access: Yes

DOI: 10.3390/lubricants10070152

Evaluation of Optimal Visible Wavelengths for Free-Space Optical Communications

Hussein Taha Modar Dayoub

Publication Name: Telecom

Publication Date: 2025-09-01

Volume: 6

Issue: 3

Page Range: Unknown

Description:

Free-space optical (FSO) communications have emerged as a promising complement to conventional radio-frequency (RF) systems due to their high bandwidth, low interference, and license-free spectrum. Visible-light FSO communication, using laser diodes or LEDs, offers potential for short-range data links, but performance is highly wavelength-dependent under varying atmospheric conditions. This study presents an experimental evaluation of three visible laser diodes at 650 nm (red), 532 nm (green), and 405 nm (violet), focusing on their optical output power, quantum efficiency, and modulation behavior across a range of driving currents and frequencies. A custom laboratory testbed was developed using an Atmega328p microcontroller and a Visual Basic control interface, allowing precise control of current and modulation frequency. A silicon photovoltaic cell was employed as the optical receiver and energy harvester. The results demonstrate that the 650 nm red laser consistently delivers the highest quantum efficiency and optical output, with stable performance across electrical and modulation parameters. These findings support the selection of 650 nm as the most energy-efficient and versatile wavelength for short-range, cost-effective visible-light FSO communication. This work provides experimentally grounded insights to guide wavelength selection in the development of energy-efficient optical wireless systems.

Open Access: Yes

DOI: 10.3390/telecom6030057