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Publications - 6383

Convergence of the key algorithm of traffic-flow analysis

László Muka G. Lencse

Publication Name: Journal of Computing and Information Technology

Publication Date: 2006-01-01

Volume: 14

Issue: 2

Page Range: 133-139

Description:

The traffic-flow analysis (TFA) [1] is a novel method for the performance estimation of communication systems. TFA is a combination of simulation and numerical methods. In the first step, TFA distributes the traffic in units of properly chosen size using the actual routing algorithm of the network. In the second step, TFA adjusts the time distribution of the traffic according to the finite capacities of the network. The convergence of the algorithm used in the second step of TFA is proven in this paper. The speed of convergence is also examined.

Open Access: Yes

DOI: 10.2498/cit.2006.02.04

Trematurid mites (Mesostigmata: Uropodina) associated with bark beetles (Coleoptera: Scolytinae) in Mexico

Jenő Kontschán Edith Guadalupe Estrada-Venegas Stacy R. Blomquist Alejandro Rodríguez-Ortega John C. Moser Martha Patricia Chaires-Grijalva Armando Equihua-Martínez Víctor Javier Arriola-Padilla Mauricio Pérez-Silva

Publication Name: Acarologia

Publication Date: 2026-01-01

Volume: 66

Issue: 2

Page Range: 364-376

Description:

Phoretic mites associated with bark beetles (Curculionidae: Scolytinae) play crucial roles in forest ecosystems, yet their diversity and distribution in Mexico remain understudied. This study aims to identify the species of the family Trematuridae (genera Trichouropoda and Oodinychus) associated with bark beetles across major coniferous forests in Mexico and to describe their host specificity and attachment patterns. A total of 1,713 bark beetles belonging to nine species were examined from 24 Mexican states. Mites were collected from the host bodies, galleries, and collection vial sediments. Eleven trematurid species were identified. Mites were recorded in ten states, with Trichouropoda polytricha being the most widespread and generalist species, associated with seven host species. A significant disparity in mite prevalence was observed among hosts, ranging from 1.57% in Dendroctonus mexicanus to 25.58% in D. rhizophagus. Phoretic deutonymphs exhibited a clear preference for specific attachment sites, primarily the ventral surface (29%) and gular area (22%). Furthermore, the presence of mites in both new and old galleries confirms these structures as essential micro-ecosystems for their biological cycle. Our findings highlight a high degree of host plasticity in certain species and a complex symbiotic relationship within the gallery environment. This research provides a fundamental baseline for future studies on the ecological impact of mite-beetle associations in Mexican forest health.

Open Access: Yes

DOI: 10.24349/qznl-uogs

Determining factors for tourist arrivals in Hungary

Ferenc Bakó Marcell Kupi

Publication Name: Journal of Infrastructure Policy and Development

Publication Date: 2024-01-01

Volume: 8

Issue: 8

Page Range: Unknown

Description:

This methodologically focused study examines the relationships between inflation and unemployment rates, political stability, and tourism, with particular emphasis on the impacts on tourist arrivals in Hungary. The research aims to uncover the direct and indirect influences of these macroeconomic indicators on the volume of tourism, specifically international tourist arrivals. The significance of the study lies in the clear correlation between economic stability and labor market conditions with tourism volume, where rising inflation and unemployment rates negatively correlate with the number of tourist arrivals. This relationship is further strengthened by the observation that improvements in political stability enhance tourist numbers over the long term, while political instability, such as conflicts and terrorist acts, negatively affects tourism demand. These correlations are crucial for aligning tourism policy with economic policy, as macroeconomic indicators and the political environment directly influence both domestic and foreign tourists’ willingness to travel. The research methodology focuses on forecasting using Random Forest and neural networks, which enables more accurate predictions of tourism volume and supports informed tourism policy-making. The findings indicate that the development of the tourism sector is closely linked to economic growth and underscore the necessity of boosting tourism to expand employment and maintain economic stability.

Open Access: Yes

DOI: 10.24294/jipd.v8i8.5862

Toward Sustainable 3D Printing: Tensile Mechanical Comparison of PLA/PBAT Biopolymer Blend and TPU in MEX Additive Manufacturing †

László Lendvai Sándor K. Jakab

Publication Name: Engineering Proceedings

Publication Date: 2025-01-01

Volume: 113

Issue: 1

Page Range: Unknown

Description:

A biopolymer blend of poly(lactic acid) (PLA) and poly(butylene adipate-co-terephtalate) (PBAT) in a 60/40 weight ratio was investigated as a potential green alternative to thermoplastic polyurethane (TPU) for material extrusion (MEX)-based additive manufacturing. A comparison of the two materials was conducted based on their tensile mechanical properties, evaluated using 3D-printed specimens fabricated with three distinct infill raster orientations (0°, ±45°, and 90°). The results showed that the tensile strengths of the two materials were relatively similar, ranging from 14.7 to 34.8 MPa, depending on the raster angle. However, the stiffness of PLA/PBAT was considerably higher than that of TPU, as reflected by Young’s modulus values an order of magnitude greater. While the elongation at break was comparable at 0° infill orientation (214% for PLA/PBAT and 265% for TPU), TPU exhibited better tolerance to increasing raster angles, with elongation only decreasing to 134% at 90°. In contrast, PLA/PBAT dropped drastically to 2%.

Open Access: Yes

DOI: 10.3390/engproc2025113022

Wear behaviour of ceramic particle reinforced atmospheric plasma spray coatings on the cylinder running surface of internal combustion engines

Ibolya Zsoldos Alexander Dudás András Lajos Nagy Gabor Laki Barna Hanula Dirk Bartel

Publication Name: Wear

Publication Date: 2022-08-15

Volume: 502-503

Issue: Unknown

Page Range: Unknown

Description:

Atmospheric plasma spray coatings can provide a solution for corrosion and wear resistant cylinder coating surfaces in hybrid powertrains. This article presents experimental results from a model study of metal matrix composite coating samples of chromium steel with varied ceramic content, in order to characterize the effect of hard particles and porous coating structure on friction and wear. Experiments were conducted on a high-frequency reciprocating rig with coated cast-iron cylinder segments and hard chromium coated piston ring segments. Samples were investigated under continuous and scarce lubrication conditions. A ceramic content of 35 wt% was found to be ideal in terms of friction and wear. Coatings with a higher ceramic content exhibited severe abrasive wear, whereas a ceramic content under 35 wt% allowed for increased adhesion between the ring and cylinder surfaces. A detailed investigation of focused ion beam milled sections of the coated cylinder wall segments revealed a stabilizing effect of the ceramic particles, which reduces the delamination of the coating structure.

Open Access: Yes

DOI: 10.1016/j.wear.2022.204373

Cognitive Classifier of Hand Gesture Images for Automated Sign Language Recognition: Soft Robot Assistance Based on Neutrosophic Markov Chain Paradigm

Áron Ballagi Oday Ali Hassen Saad M. Saad Muslem Al-Saidi

Publication Name: Computers

Publication Date: 2024-04-01

Volume: 13

Issue: 4

Page Range: Unknown

Description:

In recent years, Sign Language Recognition (SLR) has become an additional topic of discussion in the human–computer interface (HCI) field. The most significant difficulty confronting SLR recognition is finding algorithms that will scale effectively with a growing vocabulary size and a limited supply of training data for signer-independent applications. Due to its sensitivity to shape information, automated SLR based on hidden Markov models (HMMs) cannot characterize the confusing distributions of the observations in gesture features with sufficiently precise parameters. In order to simulate uncertainty in hypothesis spaces, many scholars provide an extension of the HMMs, utilizing higher-order fuzzy sets to generate interval-type-2 fuzzy HMMs. This expansion is helpful because it brings the uncertainty and fuzziness of conventional HMM mapping under control. The neutrosophic sets are used in this work to deal with indeterminacy in a practical SLR setting. Existing interval-type-2 fuzzy HMMs cannot consider uncertain information that includes indeterminacy. However, the neutrosophic hidden Markov model successfully identifies the best route between states when there is vagueness. This expansion is helpful because it brings the uncertainty and fuzziness of conventional HMM mapping under control. The neutrosophic three membership functions (truth, indeterminate, and falsity grades) provide more layers of autonomy for assessing HMM’s uncertainty. This approach could be helpful for an extensive vocabulary and hence seeks to solve the scalability issue. In addition, it may function independently of the signer, without needing data gloves or any other input devices. The experimental results demonstrate that the neutrosophic HMM is nearly as computationally difficult as the fuzzy HMM but has a similar performance and is more robust to gesture variations.

Open Access: Yes

DOI: 10.3390/computers13040106

A novel approach of quenchant evaluation by applying quality functions

Imre Czinege B. Smoljan Imre Felde Rafael Colas

Publication Name: Materials Science Forum

Publication Date: 2007-01-01

Volume: 537-538

Issue: Unknown

Page Range: 513-518

Description:

A novel numerical approach for testing and evaluation of quenching media and quenching systems is outlined. The technique proposed is based on determination of heat transfer coefficient from temperature signals recorded and applying it as input for simulation of quenching process. The evaluation method is based on the calculated microstructural and mechanical properties of cylindrical samples.

Open Access: Yes

DOI: 10.4028/0-87849-426-x.513

Optimal Plastic Reliable Design of Reinforced Concrete Beams Considering Steel Bars Volume Probability

Majid Movahedi Rad Sarah Khaleel Ibrahim

Publication Name: Mathematics

Publication Date: 2023-05-01

Volume: 11

Issue: 10

Page Range: Unknown

Description:

This paper aims to investigate the plastic response of reinforced concrete tapered beams when subjected to random steel reinforcement volumes, using both deterministic and probabilistic analyses, with the complementary strain energy as a boundary in the first case, and the reliability index as a boundary in the second. The first step in this study was to use a previously studied model and perform a deterministic analysis, assuming that the complementary strain energy is a limiting factor and controller of the plastic behaviour. Next, a probabilistic analysis is applied, with the reliability index as a limitation. At the same time, the volume of the reinforcement steel used, and the complementary strain energy were treated as probabilistic variables with mean values and specific standard deviations. This novel method highlighted the plastic behaviour limiting procedure and provided results that highlighted the nature of the model’s changed behaviour when the complementary strain energy was controlled and when applying probabilistic properties with reliability index limitation.

Open Access: Yes

DOI: 10.3390/math11102349

Mechanism of directed technological investment on energy productivity and energy structure: A unified theoretical framework

Yee Van Fan Xiaojun Sun Yalin Lei Ting Pan Petar Sabev Varbanov

Publication Name: Energy Economics

Publication Date: 2024-12-01

Volume: 140

Issue: Unknown

Page Range: Unknown

Description:

The mechanisms and effects of technological investment on energy productivity and energy structure in the petrochemical industry remain unclear due to the directional nature of technological progress. This study proposes a unified theoretical framework for the impact of directed technological investment on energy productivity and energy structure by incorporating energy factors into the theory of technological progress bias. The aim is to elucidate the impact of technological progress on energy productivity and energy structure, and to unravel the underlying effect mechanisms. A fixed effects model that includes moderating effects is also developed to support the assessment. The study found that the petrochemical industry's technological investment in China was initially biased towards enhancing labour-augmenting technological progress. The mechanism analysis revealed that technological investment, under the moderating effects of price and environmental governance, preferred a capital-energy bias, leading to insignificant improvements in energy productivity but a substantial increase in labour productivity. In addition, the technological investment, influenced by the moderating effect of environmental governance, led to some improvement in the energy structure during the sample period. This study integrates the mechanisms of directed technological investment on energy productivity and energy structure into a unified analytical framework, systematically investigating the reasons, effect mechanisms, and consequences of bias, while providing empirical evidence that supports low-carbon development in the petrochemical industry.

Open Access: Yes

DOI: 10.1016/j.eneco.2024.107943