Periodica Polytechnica (Budapest University of Technology and Economics)
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Capacity of Single-lane Roundabouts in Hungary
Get PDFRoundabouts are a prevalent type of intersection known for their potential to enhance traffic flow. Ensuring their effective design is crucial for optimizing traffic performance. This study focuses on evaluating the capacity of roundabouts, essential for both planning new installations and assessing existing ones. Field data from thirteen roundabouts in Hungary were analyzed to estimate critical gap and follow-up headway values for each entry. Employing Raff's graphical method, critical gap values were determined, while follow-up headway was calculated by averaging the time taken for two waiting vehicles to accept the same gap over eight instances. The critical gaps and follow-up headway values for all forty-one entries ranged between 2.41–3.46 s and 1.8–2.4 s, respectively. Subsequently, the Highway Capacity Manual (HCM) roundabout capacity equation was calibrated using these gap acceptance parameters. The proposed model yielded higher entry capacity (1,672 PCU/h) compared to the HCM model. Validation against actual field entry capacity values demonstrated a strong correlation (R2 = 0.94), affirming the model's accuracy. Comparisons with international models, such as HCM 2016, Brilon-Wu, and Brilon-Bondzio, revealed the superiority of the proposed model in terms of entry capacity (1,672 PCU/h versus 1,380 PCU/h, 1,241 PCU/h and, 1,218 PCU/h respectively)
Hydrothermal Synthesis and Photocatalytic Efficiency of Turmeric Leaves Biochar/TiO2 Composite for Photooxidation of Congo Red Dye
Get PDFThe hydrothermal synthesis of an eco-friendly photocatalyst using turmeric leaves biochar (TLB) and titanium dioxide nanoparticle composite has been reported for the degradation of Congo Red (CR) dye. The synthesized composite was characterized using various analytical techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) analysis, Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS), confirming its structural and morphological attributes that ensured the uniform dispersion and intimate contact between TLB and TiO2 particles. The degradation performance of the TLB/TiO2 composite was examined by using UV light irradiation as a catalyst. The results demonstrated that the TLB/TiO2 composite exhibited superior photocatalytic activity compared to pristine TiO2, attributed to the enhanced light absorption, improved charge separation, and increased surface area provided by the biochar. The degradation kinetics followed a pseudo-first-order model, with a significant reduction in the dye concentration within a short time frame. The eco-friendly nature, cost-effectiveness, and high photocatalytic efficiency of the TLB/TiO2 composite highlight its potential application in wastewater treatment, thus providing a novel approach to valorize agricultural waste into functional materials for sustainable environmental technologies
Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES): Exploring Versatile Applications in Industrial and Analytical Fields
Get PDFThe first inductively coupled plasma optical emission spectroscopy (ICP-OES) instrument became commercially available more than 50 years ago, in 1974. Over recent decades, it has emerged as a key spectroscopic technique for analyzing numerous elements, offering a powerful tool for elemental analysis at milliparticle (ppm) and parts-per-billion (ppb) levels. This comprehensive review highlights the applications of ICP-OES across various scientific disciplines, with a particular focus on pharmaceutical technology, illustrated through a practical solution
Multi-objective Variants of Water Strider Algorithm for Construction Engineering Optimization Problems
Get PDFMany engineering problems require optimizing multiple conflicting objectives simultaneously, necessitating efficient exploration of the design space for balanced solutions. The Water Strider Algorithm (WSA) is a robust metaheuristic technique that demonstrates superior performance compared to traditional evolutionary algorithms. This study evaluates two multi-objective variants of WSA: the Grid-based Multi-objective Water Strider Algorithm (GMOWSA) and the Non-dominated Sorting Water Strider Algorithm (NSWSA). Both variants incorporate a selection mechanism that archives and prioritizes high-quality solutions, emulating the natural behavior of water striders. The proposed methods are tested on nine multi-objective benchmark functions and three construction engineering optimization problems to assess their effectiveness. Comparative analysis against three state-of-the-art algorithms demonstrates that GMOWSA and NSWSA achieve competitive results, showcasing their potential for solving complex multi-objective optimization challenges in engineering applications
The Aspects of Urban Character in József Kerényi's Works in the Great Hungarian Plain
Get PDFJózsef Kerényi's work at the Bács-Kiskun County Planning Company (BÁCSTERV) between 1964 and 1984 is significant both for the built heritage of the county and its centre, Kecskemét and for the history of Hungarian architecture and urban planning. While several aspects of Kerényi's architectural legacy have been studied, a focus on the urban scale aspects of his oeuvre has been lacking. This study examines his oeuvre from the perspective of urban context and urban character. Additionally, beyond individual buildings, this study incorporates his urban-scale projects into the analysis. The research focuses on Kerényi's interpretation of heritage and his responses to urban character. The study addresses the relationship between historical urban fabric and new developments, the interpretation and evaluation of historical urban fabric, the concept of rehabilitation, and the relationship between architecture and urban planning. The research aims to uncover the planning processes and theoretical approaches that help to understand and contextualise Kerényi's activities in the Great Hungarian Plain. The investigation targets the cityscape and urban structure dilemmas and how city character influenced the answers to these questions. Furthermore, the study seeks to examine how Kerényi's ideas relate to both Hungarian and international trends of the period
The Effect of Stator and Rotor Faults on the Dual-star Induction Motor Behavior
Get PDFDual-star induction machines (DSIMs) are widely used in automated production systems that require uninterrupted service. As they mostly operate under dynamic real-time conditions, faults can significantly accelerate the degradation of critical components in variable-speed and load regimes. Therefore, robust monitoring algorithms are essential to assess damage levels and failure modes as faults evolve. For this purpose, a proposed approach leverages the Hilbert envelope spectrum to extract fault-related frequency components from stator current signals, providing a basis for identifying both broken rotor bar (BRB) and inter-turn short circuit (ITSC) faults. A key feature of this methodology is the use of a health indicator, derived from the current envelope spectrum to address challenges associated with damage level and load conditions from a signal processing perspective. Crucially, the relationship between the health indicator, fault severity, and load variations is statistically modeled using surface fitting. The stator current signals required for evaluating the approach are gathered from different simulations of the DSIM, subjected to various levels of damage and load conditions. The results obtained suggest that the third-order polynomial could be sufficient to model the relationship. These comprehensive analyses conclusively demonstrate the efficacy and practical applicability of the proposed fault detection approach, thus contributing significantly to the understanding of electrical machine reliability and fault mitigation
A New Hybrid Water Cycle Algorithm for Path Planning with Obstacle Avoidance for Indoor Assistant Autonomous UAV Navigation
Get PDFAssisting elderly individuals in indoor environments is crucial, as they often encounter mobility and safety challenges. Autonomous Unmanned Aerial Vehicles (UAVs) navigation offers a transformative solution, significantly enhancing safety, efficiency, and quality of life. These UAVs can perform tasks such as monitoring, delivering essential items, and responding to emergencies, providing invaluable support and promoting greater independence for elderly individuals. To achieve effective assistance, autonomous UAV navigation relies on robust path planning with obstacle avoidance to ensure optimal performance. A newly developed path planning, based on a new hybrid Water Cycle Algorithm (WCA), stands out by addressing the challenge of avoiding obstacles while adhering to non-holonomic constraints and conserving energy in complex, cluttered indoor environments. In Population-Based Algorithms (PBAs), the initial population plays a crucial role, as it greatly impacts the algorithm’s efficiency in exploring the search space and its rate of convergence. The new developed hybrid algorithm, called WCA-HS, is based on using the Harmony Search (HS) algorithm to identify the optimal initial population for the WCA. The results indicate that the hybrid WCA-HS outperforms classical WCA and other metaheuristic algorithms, such as HS, Firefly Algorithm (FA), Cuckoo Search (CS), Genetic Algorithm (GA), Differential Evolution (DE), Ant Colony Optimization (ACO), and Artificial Bee Colony (ABC), over 20 independent runs, highlighting the effectiveness of the population initialization technique. Additionally, the developed indoor path planning system was evaluated in highly cluttered and low-light environments, showcasing its robustness and real-world applicability, making it highly effective for assisting elderly individuals in complex indoor environments
Parametric Analysis of Facade Characteristics and Natural Ventilation Strategies in a Budapest Office Building
Get PDFThis study investigates the impact of window glazing, window-to-wall ratio (WWR), natural ventilation strategies, and shading on energy efficiency and lighting performance in a case study office building in Budapest, Hungary. Using DesignBuilder software for building performance simulation, various configurations of double and triple glazing, with and without shading, are analyzed across WWRs of 10% and 50%. The study evaluates heating, cooling, and lighting energy consumption to identify design strategies that optimise energy performance and visual comfort. Results indicate that triple glazing with shading and a 50% WWR delivers the most efficient performance by reducing electricity consumption through effective solar heat gain control and enhanced daylighting. In contrast, unshaded large glazing areas lead to higher cooling demand, decreasing overall efficiency despite improved daylight access. Additionally, the study examines three natural ventilation strategies for summer: (1) constant ACH of 0.5 during day and night, (2) high daytime ACH with minimized nighttime ACH, and (3) continuous high ACH. Findings show that the second strategy provides the best thermal comfort but results in the highest energy use, while the first scenario achieves the lowest energy consumption at the expense of comfort. The third approach offers a balanced compromise between comfort and energy performance. These findings highlight the importance of combining façade design elements with appropriate ventilation strategies to maintain thermal comfort and reduce energy consumption in office buildings
Neural Networks Approach to Remodel Capacity on Urban Road and Street Network
Get PDFThe growing number of cars and trucks in cities leads to traffic jams and accidents. To solve this problem, cities have to use smart transportation systems powered by artificial intelligence models and machine learning techniques. An important parameter of transportation systems showing the effectiveness of using existing urban infrastructure is the capacity of the planned route. The paper is devoted to the modeling of urban route capacity based on the capacities of its elements, namely stretches and intersections. The approach to create such a model is Mathematical Remodeling, where feed-forward neural network is chosen as a unified class to substitute models of different heterogeneous classes during modeling. It is proposed to use index of route capacity to form data sets for model fitting. The given numerical examples show how the proposed approach can be applied. The capacities of three planned routes are estimated and the best route is chosen, the efficiency criterion is traffic flow volume to capacity ratio. The prospective issue of the presented study is analyzing sensitivity of the created model to identify the parameters of route elements that most capacity and to control them increasing the total efficiency of the system
Nicholas Mazza Irodalomterápia című könyvének magyar nyelvű kiadásáról – recenzió
No full textKönyvismertetőMazza, N. (2025) Irodalomterápia. Elmélet és gyakorlat. Ford. Béres, J., Multiverzum Kiadó, Budapest, p. 304. ISBN: 978-615-666-213-