Periodica Polytechnica (Budapest University of Technology and Economics)
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Road Truck Accident Rate in Terms of Major Causes: A Case Study
Get PDFThe aim of this paper is to familiarize the reader with a case study of the main causes of road trucks' (RT) accidents on roads by applying analytical methods and a questionnaire survey. In the introductory part of the paper, the theoretical foundations in the field of road safety from the view of road infrastructure and vehicle construction, which are applied nowadays to prevent and minimize the severity of traffic accidents, are briefly described. Subsequently, the above-mentioned issues are applied in a real environment, when, based on the analysis of registered traffic accidents of RT and a questionnaire survey among professional drivers, the main causes of these accidents were identified and measures were proposed, including the possibility of their implementation in real traffic conditions. In the final part of the paper, a short evaluation of the variants of measures is carried out in terms of the expected impact on the accident rate
Contribution of Certain Enablers to Success Criteria of Science and Technology Parks
Get PDFThe paper aims to cover a research gap in the analysis of certain enablers and their role in the success of science and technology parks (STPs). The goal of the research was to analyse the features of the enablers and point out their potential relationships with various success criteria. The outcomes of the research will help park management better understand STP behaviours. The analysis was done based on the survey data of 113 STPs. After definitions of enabler areas and success criteria plus a literature review, first the interrelations of enabler elements have been analysed using the Association Rule Mining method. Then, their relationship towards eight success criteria measurements have been studied using statistical analysis in order to find the key success drivers. Such a combination has rarely been used for analysing STPs in related research. According to the findings, there are apparent patterns and features within the analysed enabler areas. This is unique feature of the current paper, which highlights the necessity of taking a complex approach towards park services. It underlines the need for research, development and innovation competences and structures in STPs. The statistically relevant enablers as success drivers have revealed the importance of the presence of several factors (like management behaviour, park activities, service elements, etc.). This underlines that balanced development is crucial to successful parks achieving high-level performance
A Nemzeti Kulturális Alap Közgyűjtemények Kollégiuma könyvtári szakterületének nyílt pályázati felhívása
No full textThe Last 5 Years of Maritime Shipping: Special Focus on Trade Relations between Hungary and China
Get PDFToday, it has become unthinkable for a company to produce its products using only local raw materials and semi-finished products. Thus, economic systems depend highly on cheaper raw materials from other continents or semi-finished and finished products. One obvious solution for transporting these raw materials is to use maritime transport. In this research, the trends in sea container transport over the last 5 years have been examined in terms of sea container transport and Hungary's main trading partners, with a special focus on China. As a starting question, the impact of the pandemic period on the value of sea freight trade was formulated. In addition, the volumes of containers handled worldwide were examined, and how the European and Asian regions reacted to the impact of the virus. The research concluded that although the COVID-19 virus has affected and transformed the entire world, in many respects, the maritime transport industry has remained a stable and prominent industry during the period under study. In addition, in terms of trade, although Germany and the European Union are certainly Hungary's main trading partners, the trade relationship with China has been growing in recent years, especially in terms of import values, and it is important to highlight the Republic of Korea in terms of the same trend
Enhancing Carbon Dioxide Separation Efficiency in Mixed Matrix Membranes Using Titania Nanoparticles and Polyether Sulfone
Get PDFMembrane science is an advanced, environmentally sustainable technology that provides distinct advantages over traditional methods for CO2 capture and separation. In this study, mixed matrix membranes were synthesized by incorporating varying concentrations of titania into polyethersulfone using the phase-inversion technique for the separation of CO2/CH4 and CO2/N2 gas mixtures. Thermal, chemical and morphological analysis demonstrated the beneficial impact of TiO2 on the performance of MMMs, particularly when compared to the pristine membrane. Moreover, the TiO2 loading was shown to improve gas separation performance by reducing the thickness of the dense layer and increasing permeability through uniform filler dispersion. The highest value of optimum selectivity (CO2/CH4) was attained with 3 wt% TiO2 loading, which is 22.3% more than that of the pristine membrane. This performance is attributed to strong interfacial interactions between polyethersulfone and TiO2 at this specific loading, as illustrated by the morphological diagram
Probabilistic Stability Analysis of an Open-pit Dolomite Quarry in Hungary
Get PDFDue to inherent geological uncertainties, slope stability is a critical factor in open-pit mining operations. These uncertainties affect stability assessments, including spatial variability, weathering, and human factors. The quarry in Vilonya, Hungary, excavates dolomite rock, characterized by fragmentation and variable joint conditions. Post-mining, stability is assessed to determine whether slopes can maintain steeper angles than the standard 45°. This study evaluates the stability of slopes in the Vilonya dolomite quarry using probabilistic methods to account for geotechnical variability and to assess the feasibility of steeper slope angles. A combination of field measurements, laboratory tests, and computational analyses were employed. Joint orientations and roughness were determined through photogrammetry and Barton comb measurements. Statistical analysis of rock parameters were done by software like Analytic Solver. Stability was analyzed using Rocscience software (Dips, RocPlane, SWedge, Slide2) for various failure mechanisms, including planar and wedge sliding, as well as global stability. Kinematic analyses identified critical joint sets that may contribute to slope failure. Probabilistic assessments showed that some joint intersections present failure probabilities as high as 67.42% for wedge failure, while planar sliding risks were negligible. Global stability analysis indicated no critical failures, with safety factors consistently above 1.35 across all slopes. Probabilistic methods reveal significant insights into slope stability that deterministic approaches may overlook. The study confirms the feasibility of maintaining steeper slope angles under controlled risk, optimizing extraction while ensuring stability. Incorporating probabilistic analysis is recommended for reliable slope design in similar geological settings
Automated Graph Theoretic Force Method and its Application in Optimal Design of Frame Structures
Get PDFIn this study, the graph-theoretic force method is applied to the optimal design of frame structures and systematically compared with the conventional displacement method. The optimization is performed using the Water Strider Algorithm (WSA), a recently developed bio-inspired metaheuristic, whose population-based search strategy is integrated with both analysis approaches. To ensure reproducibility, all key WSA parameters are reported, and large-scale highly indeterminate frame examples (up to 292 members) are tested, extending beyond previous benchmark studies. In addition, a counterexample with DKI < DSI is included, demonstrating that the relative efficiency of the two methods is problem-dependent rather than universal. The results show that for large-scale highly indeterminate frames, the graph-theoretic force method combined with WSA significantly reduces computational time while maintaining accuracy comparable to the displacement method. These findings highlight both the scalability and the limitations of the graph-theoretic force method, offering a balanced perspective for its practical application in structural optimization
An Experimental Study on the Topography Effects on the Seismic Response of Combined Piled Raft Foundation
Get PDFThe effect of topography on the amplification of seismic forces has been considered in regulations, and they have deemed the use of the seismic force amplification coefficient in the design of adjacent earth-retaining structures necessary. However, the impact of settlement-reducing or anti-sliding piles under the building foundation on the applied acceleration to the foundation is generally not addressed in regulations, and it is necessary to carefully examine this issue for the optimal design. This study sought to empirically assess the impact of using piles as Combined Piled Raft Foundation (CPRF) positioned on the top of slopes, with different slope angles, on the seismic behavior of slopes, scaled at 1/25th, through shaking table experiments. Six sinusoidal waves were created as input motions to simulate a range of earthquake scenarios, applied to the models to collect data for analyzing the seismic response of the system. No.161 Firouzkooh sand was utilized as the soil in this investigation. The amplification factor (AF) of various locations was used to examine the seismic response of the system. The findings underscore the importance of the amplification factor as a critical parameter in evaluating the seismic response of foundations situated on slope crests. Additionally, Implementing CPRF and longer piles had a mitigating effect on accelerations at most points and improved the seismic response of the slopes, reducing amplification factor and led to less damages. Furthermore, the slope angle was shown to significantly influence the seismic response, with steeper angles generally resulting in higher amplifications at the slope crest
Image Acquisition of Critical Bridge Components Using Vision-guided Autonomous Vehicle
Get PDFThis research proposes a vision-guided autonomous navigation framework for unmanned vehicles performing image acquisition for bridge inspection. The proposed framework integrates visual SLAM with RGB-D image input with semantic segmentation to detect and localize critical structural components like columns. The detected components are converted to the parametric map to generate navigation goals for image collection. The proposed approach is first validated in the synthetic bridge inspection environment using an unmanned ground vehicle. The feasibility of the framework is further studied by the laboratory-scale prototyping and validation using TurtleBot3 equipped with Jetson TX2 onboard computer. In the simulation environment, the proposed framework can achieve autonomous navigation to up to 6 columns and acquisition of image data with 90% success rate for 3 columns. Furthermore, the performance evaluation in the real-world environment shows that the developed hardware-software prototype can navigate and collect image data of up to 2 columns, with more than 60% success rate navigating to the first column. The results indicate the significant potential of achieving autonomous navigation and image acquisition with limited onboard computational resources, contributing to the enhanced efficiency and reliability of bridge management