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Publications - 6374

Land-use zone estimation in public transport planning with data mining

Richárd Horváth Balázs Horváth Viktor Nagy

Publication Name: Transportation Research Procedia

Publication Date: 2017-01-01

Volume: 27

Issue: Unknown

Page Range: 1050-1057

Description:

Nowadays, data sets are spreading continually, generated by different devices and systems. The modern GPS based tracking systems and the electronic tickets are producing lots of data, and we could use them, for improving the service level. These data are processable with the modern devices and methods, and we can use them for obtaining information. Thanks to the spread of data mining, these tools are not appearing only in marketing research, but also in the most various kind of scientific areas and they are advertising a new scientific revolution. Although the importance of these data sources is essential it is not widespread in transport planning except in some specific areas. The smart card systems store the number of boarding passengers and in some cases also the alighting values. From the passengers' boarding and alighting information in a stop point we can create a time series, which shows the behavior type of the given stop points presented on graphic curves. With the help of different clustering and classification processes, these curves can be turned into groups and we can observe these groups of stop points which are defining separated zones. This is the basic step in transport modelling and the zones were determined by manual methods usually. In this paper we examine clustering and classification methods compared to each other and check the usability of different distance measurement techniques. This paper shows the usage of these methods in public transportation and presents the background of this kind of zone distribution technic.

Open Access: Yes

DOI: 10.1016/j.trpro.2017.12.145

Sustainable Uses of 3D Printing Applied to Concrete Structures †

Szabolcs Fischer Szabolcs Szalai Hanna Csótár Gusztáv Baranyai

Publication Name: Engineering Proceedings

Publication Date: 2024-01-01

Volume: 79

Issue: 1

Page Range: Unknown

Description:

This study investigates the application of honeycomb-patterned PLA as a reinforcement in concrete structures. The research focused on identifying the optimal 3D printing layout for this reinforcement and examining how the orientation of 3D-printed PLA affects the mechanical properties of the concrete. The study compares the performance of concrete reinforced with 3D-printed PLA to both unreinforced concrete and concrete reinforced with recycled amorphous aggregate from printing waste. The results demonstrate how printing orientation influences concrete strength and the potential for using recycled PLA to enhance sustainability in construction.

Open Access: Yes

DOI: 10.3390/engproc2024079055

Concept of a Novel Energy Management System for Microgrids and Energy Communities

Balázs Vehovszky Zoltán Weltsch Bernadett Rádli-Burján Ferenc Magyar Lóránt Kovács

Publication Name: Chemical Engineering Transactions

Publication Date: 2024-01-01

Volume: 114

Issue: Unknown

Page Range: 919-924

Description:

The green transition of the global energy system presents considerable economic and technological challenges. One of them is the local and temporal difference between available energy sources and energy demand. To overcome this problem, two conceptual solutions can be considered: one is the use of an energy carrier that is suitable for medium- and long-term storage and safe transportation of energy. Carbon-based fuels (or novel alternatives, like hydrogen) or electric energy are the solutions currently used; however, we are facing their environmental or technical limitations. The other one is the synchronisation and intelligent control of sources and consumers, which could significantly decrease the storage and transportation needs. The current article discusses such a solution through a conceptual example. For the conceptual design of an advanced energy management system, the main related system elements shall be defined, and characteristic properties must be assigned to them. Input parameters for the energy management strategy must be given and prioritised. All this information enables the system to calculate and define instantaneous operational optimum. Also, an intelligent control system should take time-dependent processes and parameters into account, which can be deterministic or stochastic. As a result of this study, an energy management system concept that is based on realistic components and use cases is proposed, and its applicability to a local energy community is evaluated.

Open Access: Yes

DOI: 10.3303/CET24114154

Sentinels of Sustainability: Practices of Agricultural Farms Clustered in Hungary’s Farmers’ Markets

Károly Kacz Judit Petra Koltai Szabolcs Troján Tamás Vinkóczi Anita Miklósné Varga

Publication Name: Chemical Engineering Transactions

Publication Date: 2024-01-01

Volume: 114

Issue: Unknown

Page Range: 973-978

Description:

The analysis of local farmers' markets (FMs) is an important part of sustainability issues, as the products they offer can guarantee both the proper functioning of local farms and healthy nutrition for inhabitants. The aim of this research is to identify the most important characteristics of FMs small-scale businesses related to agricultural activities based on a convenience sample in Hungary. The database obtained by the questionnaire survey was compiled based on the answers of a total of 220 farm owners/managers. The results were subjected to analysis using a K-means clustering method, which identified four distinct groups of farms with the highest weighting of turnover from agricultural activity. The clustering distinguished beekeeping, arable crop production, animal husbandry, and vegetable and fruit production, which were treated as a separate cluster. The observed differences between the groups indicate that farms primarily engaged in beekeeping and livestock farming have the highest turnover. These findings may be manifested by the group’s member farms in terms of higher professional representation and high-quality products. A noteworthy distribution-related finding is that livestock products exhibit the greatest average distance from the point of origin to the FM, which can be attributed to the sparse geographical location of the production sites. The results could have a considerable consequence for policymakers in informing them about the design of support opportunities and the identification of beneficiary groups.

Open Access: Yes

DOI: 10.3303/CET24114163

Comparison of Extended and Unscented Kalman Filters with and without Using Mechanical Model for Speed Sensorless Control of Induction Machines

Krisztian Horvath

Publication Name: 2023 18th Conference on Electrical Machines Drives and Power Systems Elma 2023 Proceedings

Publication Date: 2023-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

In this work, speed sensorless state estimators are compared for induction machine drives. The studied estimators are based on two widely used state-space models. The first one has five state variables and assumes slowly varying rotor speed. In contrast, the second model is augmented by the equation of motion and the load torque is defined as an additional state variable. Due to the nonlinearities, extended and unscented Kalman filters are applied in the case of both models. To compare the parameter sensitivities and the low speed operation of the four state estimators, simulations and experiments are carried out. In addition, the estimators are also tested in speed sensorless closed-loop control structure.

Open Access: Yes

DOI: 10.1109/ELMA58392.2023.10202302

Expanded scope of traffic-flow analysis: Entity flow-phase analysis for rapid performance evaluation of enterprise process systems

László Muka Gábor Lencse

Publication Name: Esm 2006 2006 European Simulation and Modelling Conference Modelling and Simulation 2006

Publication Date: 2006-01-01

Volume: Unknown

Issue: Unknown

Page Range: 94-98

Description:

This paper describes entity-flow phase analysis (EFA) which is a method for fast performance analysis of organisational process systems. EFA, similarly to traffic-flow analysis for communication systems (TFA), uses the combined approach of simulation and numerical methods. In simulation projects initiated to support the design of Information and Communication Technology (ICT) system and Business Process (BP) system in an organisation the parallel analysis of different systems may be efficient. EFA is a promising evaluation method to be applied for systems with determined BP and ICT subsystems in an organisational environment.

Open Access: Yes

DOI: DOI not available

Fractal geometry-based Klein-Gordon model for heat and mass transfer in a cylindrical cavity with variable thermal conductivity

Abhik Sur Wei Peng Hijaz Ahmad Soumik Das Taha Radwan Vipin Gupta

Publication Name: Propulsion and Power Research

Publication Date: 2026-03-01

Volume: 15

Issue: 1

Page Range: 179-196

Description:

This study presents a generalized framework of vector calculus for non-integer dimensional spaces, motivated by the prevalence of fractals in nature. The work formulates first- and second-order differential operators, including gradient, divergence, and scalar and vector Laplacian, for scalar and rotationally covariant vector functions. This framework is applied to the thermoelastic response of an infinite fractal medium with a cylindrical cavity, a problem that incorporates thermoelastic mass diffusion and variable thermal conductivity through the Kirchhoff transformation. The system is analyzed under combined thermal and chemical shocks at the boundary, with the medium remaining mechanically fixed. The governing equations are solved using the Laplace transform method, and Zakian technique is employed for numerical inversion. The computational results indicate that parameters such as delay time and fractal dimension significantly influence the material's response. The graphical analysis visually examines the effects of different kernel functions, fractal dimension, variable thermal conductivity, nonlocal length and time scales on the thermoelastic response, providing a clear illustration of their impact. Specifically, an increase in fractal dimension leads to a more pronounced reduction in the thermoelastic response near the cylindrical cavity. Furthermore, an examination of different memory-dependent kernel functions reveals that nonlinear kernels demonstrate superior performance compared to linear kernels within this theoretical framework.

Open Access: Yes

DOI: 10.1016/j.jppr.2026.02.007

A distance model for safety-critical systems

Miklós Szijártó Gábor Kallos Dietmár Gröger

Publication Name: Periodica Polytechnica Electrical Engineering

Publication Date: 2001-01-01

Volume: 45

Issue: 2

Page Range: 109-118

Description:

In this paper we introduce a new, theoretical model for safety-critical systems in which the distance from the dangerous conditions can be measured. To describe these systems we use besides the graph model Petri nets, too. We illustrate the theoretical discussion with some simple examples.

Open Access: Yes

DOI: DOI not available

Nitrogen Management in Crop–Soil–Environment Systems: Pathways Toward Sustainable and Climate-Resilient Agriculture

Szilvia Veres Zed Rengel Tarek Alshaal Nevien Elhawat

Publication Name: International Journal of Molecular Sciences

Publication Date: 2026-03-01

Volume: 27

Issue: 5

Page Range: Unknown

Description:

Abiotic stresses including drought, salinity, heat, cold, and heavy metal toxicity severely constrain plant productivity worldwide. Nitrogen (N), beyond its fundamental nutritional role, has emerged as a central regulator of plant stress responses through its involvement in metabolic reprogramming, osmotic adjustment, antioxidant defense, and hormonal signaling. This review synthesizes current advances in understanding how nitrogen availability and form influence plant tolerance to major abiotic stresses. Particular emphasis is placed on nitrogen-mediated modulation of reactive oxygen species (ROS) scavenging systems, nitrogen–carbon metabolic coordination, phytohormonal crosstalk, osmoprotectant biosynthesis, and regulation of stress-responsive gene expression. Recent molecular insights highlight the role of nitrogen transporters, nitrate signaling pathways, and nitrogen-use efficiency in stress adaptation mechanisms. Furthermore, agronomic and biotechnological strategies aimed at optimizing nitrogen management to enhance stress resilience are discussed, including precision fertilization, integrated nutrient management, and genetic approaches targeting nitrogen-responsive regulatory networks. By integrating physiological, biochemical, and molecular perspectives, this review provides a comprehensive framework for understanding nitrogen-driven mitigation strategies under abiotic stress conditions and outlines future research directions for sustainable crop production in changing environments.

Open Access: Yes

DOI: 10.3390/ijms27052477