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Publications - 6374

Conservative Method for the Calculation of Thermal Forces in Reinforced Concrete Tunnel Wall During Fire

Éva Lublóy Zoltán Major János Szép

Publication Name: Advances in Transdisciplinary Engineering

Publication Date: 2024-01-01

Volume: 59

Issue: Unknown

Page Range: 455-463

Description:

This article builds on the author's existing knowledge of the heating of reinforced concrete tunnel linings and deals with the structural analysis of tunnel linings under fire exposure. Due to space constraints, the issue of designing for earth pressure and surface loads is not address. Since the analysis of thermal stresses due to restrained deformations is insufficient in the available literature, we complement the existing theoretical knowledge with the knowledge provided by the relevant standards for reinforced concrete tunnel linings. In addition, we add our own individual reflections to the theory where we have identified gaps. In determining the additional stresses due to inhibited thermal expansion, we use a numerical model based on our own ideas. The reason for this is that the heating of reinforced concrete tunnel lining during fire is extremely uneven and it is almost impossible to take this into account in the finite element programs commonly used. The other important reason is that this uneven temperature change that causes the colder zones of the wall to inhibit deformation. Thus, a solution implemented in MS Excel environment is presented, which allows an approximate accurate determination of the force effects due to inhibited deformation. The solution used and the values proposed are based on the authors' individual ideas and are not the result of an accepted professional consensus. In all cases where more precise data are required, it is recommended that a more accurate test be carried out. Advanced finite element modelling can provide the necessary support for designers and experts.

Open Access: Yes

DOI: 10.3233/ATDE240579

ASSESSMENT OF TRAFFIC SIGN RETROREFLECTIVITY FOR AUTONOMOUS VEHICLES: A COMPARISON BETWEEN HANDHELD RETROREFLECTOMETER AND LIDAR DATA

Csaba Koren Ziyad N. Aldoski

Publication Name: Archives of Transport

Publication Date: 2024-01-01

Volume: 70

Issue: 2

Page Range: 7-26

Description:

This study investigates the critical role of retroreflectivity in traffic signs, particularly in the context of autonomous vehicles (AVs), where accurate detection is paramount for road safety. Retroreflectivity, influencing visibility and legibility, is essential for ensuring safe road conditions. The study aims to assess traffic sign retroreflectivity using handheld retroreflectometers and LiDAR data, offering a comprehensive comparison of results with a specific focus on the RA1 and RA2 traffic sign classes. In a real-world setting, an AV equipped with LiDAR sensors, GPS units, and a stereo camera collects data on traffic signs, including point cloud attributes such as intensity and density. Simultaneously, a handheld retroreflectometer measures retroreflectivity coefficients from identified traffic signs. While retroreflectometers provide precision, they face limitations regarding time-consuming measurements and handling large or elevated signs. In contrast, LiDAR systems efficiently evaluate retroreflective features for numerous signs without such constraints. Despite both methods consistently yielding accurate retroreflectivity, the study reveals a limited correlation between LiDAR point cloud data and handheld retroreflectivity coefficients. The implications of these findings are significant, particularly in the selection and maintenance of retroreflective materials in traffic signs, with direct repercussions on overall road safety. The results offer valuable insights into leveraging LiDAR technology to enhance AVs' detection capabilities. Recommendations for further research include exploring factors influencing LiDAR intensity, establishing a more accurate relationship between intensity and retroreflectivity, correcting the point cloud during intensity calibration, and testing empirical prediction models with a larger sample size. These endeavors aim to generate a robust regression graph and determine correlation coefficients, providing a more nuanced understanding of the intricate relationship between LiDAR data and handheld retroreflectivity coefficients in the context of traffic sign assessment.

Open Access: Yes

DOI: 10.61089/aot2024.qxy24g93

Enhancing Safety-Critical Brake System Testing with Vector SIL over Complex Vector HIL †

János Májer Balázs István Németh Péter Panyi Félix Tivadar Nagy Denes Fodor

Publication Name: Engineering Proceedings

Publication Date: 2024-01-01

Volume: 79

Issue: 1

Page Range: Unknown

Description:

Advanced vehicle technologies that substitute or assist the driver are crucial and safety-critical elements, including independently acting electronic control units. A key element of vehicle road safety is its behavior on the road, influenced by various factors such as adhesion and physical forces. Self-activating brake systems, including related sensors and processing units, are vital for modern autonomous vehicles. The complexity of software in vehicle electronic control units (ECUs) has significantly increased, making traditional testing methods inadequate. This paper explores the use of Software-in-the-Loop (SIL) and Hardware-in-the-Loop (HIL) testing methods in an automated test environment to enhance software development and testing processes. It can be demonstrated that there is interoperability between the HIL and SIL systems using the same test case implementation in the Vector CANoe simulation environment. As a result, it can be demonstrated that in the case of a safety-critical function, such as an ABS (anti-lock brake system) control intervention, the ECU control software behaves the same in both the HIL and SIL simulation environments.

Open Access: Yes

DOI: 10.3390/engproc2024079034

Optimizing complex building renovation process with fuzzy signature state machines

Gergely Molnarka Laszlo T. Koczy

Publication Name: Lecture Notes in Computer Science Including Subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics

Publication Date: 2014-01-01

Volume: 8835

Issue: Unknown

Page Range: 573-580

Description:

In contrary to recently built office and commercial buildings, the service life of the traditional European residential houses was not calculated. Some estimations exist about the life span of different types of building constructions, however, these estimations may not reassure the owners of urban-type residential houses that were built before the second world war. A thorough and professional renovation may extend the service life of buildings by decades, the question is how to prepare the most effective renovation procedure.As a combination of the fuzzy signature structure and the principles of finite-state machine a new formal method is proposed for generating a tool for supporting the renovation planning, concerning the costs and importance of repair. With the support of information obtained from a given pre-war urban-type residential house, the available technical guides and the contractors’ billing database an optimized renovation process of the roof structure is presented as a case study.

Open Access: Yes

DOI: 10.1007/978-3-319-12640-1_69

Nonlinear Identification of Lateral Dynamics of an Autonomous Car Vehicle †

Dániel Pup György Istenes Ferenc Szauter József Bokor

Publication Name: Engineering Proceedings

Publication Date: 2024-01-01

Volume: 79

Issue: 1

Page Range: Unknown

Description:

In this paper, the nonlinear identification of the lateral dynamics of a road vehicle and the velocity dependence of the dynamics are presented. One of the most useful methods to define the mathematical model is system identification based on measured data. A test vehicle for autonomous driving was constrained to move in a straight line while the vehicle’s steering servo was artificially excited. The input of the system is therefore the sum of the artificial excitation and the control signal of the autonomous function, and the output is the lateral acceleration of the vehicle. The measurements are used to identify Wiener and Hammerstein models of the lateral dynamics at different speeds using nonlinear methods. The aim is to investigate the velocity dependence of the dynamics.

Open Access: Yes

DOI: 10.3390/engproc2024079053

OLD AND NEW CHALLENGES IN REGIONAL DEVELOPMENT – COMPARATIVE ANALYSIS OF EUROPEAN REGIONAL DEVELOPMENT POLICY APPROACHES TO IDENTIFYING BENEFICIARY REGIONS

Katalin Mezei Gábor Mayer

Publication Name: Deturope

Publication Date: 2025-01-01

Volume: 17

Issue: 3

Page Range: 50-74

Description:

Most European countries apply development policy solutions to help disadvantaged regions catch up and seek effective solutions for territorial cohesion. This endeavour has been strongly supported by the European Commission in both the 2013-2020 and 2021-27 programming periods and is likely to remain so in the period after 2028. This is an understandable and logical endeavour, as being 'left behind' in economic, social or geographical terms not only reinforces internal migration flows within the European Community and its Member States but also increases political discontent. A number of approaches have emerged in European countries to identify disadvantaged regions and address their problems. The differences stem partly from the different intervention intentions of individual countries and partly from their different spatial, state and public administration structures. Various development policy solutions have been devised to help disadvantaged regions catch up, taking these factors into account. In Hungary, development policy has placed greater emphasis on the catching up of regions and settlements lagging behind in terms of socio-economic development since the 1980s, but the importance of delimitation in development policy practice has increased since the country's accession to the EU, with the establishment of differentiated support resource allocation mechanisms and targeted support programmes. The methodology currently in use for designating beneficiary regions has been in place since 2014. The socioeconomic changes that have taken place since then have shifted the focus of both scientific and policy interest in recent years towards more location-specific regulatory mechanisms that measure development differences at a lower level and are more sensitive to functional links between settlements. To support efforts in the renewal of the Hungarian regional development toolkit, our study seeks to outline alternative options by analysing Italian and British development policy practices, in addition to presenting Hungarian beneficiary regions. The international examples examined, despite their limitations as presented in the study, provide examples of multi-level governance, development policies based on functional units, and methodologies for measuring development below the settlement level. Current legislation in Hungary allows for changes in this direction, but their incorporation into domestic practice is only possible after careful preparation.

Open Access: Yes

DOI: DOI not available

Egysejt-fehérje előállítása állati takarmányozáshoz fermentációs biotechnológiával

Renato Kalocsai Mukhtar H. Ahmed Judit Molnár Dávid Vasas Tamás Szakál

Publication Name: Elelmiszervizsgalati Kozlemenyek

Publication Date: 2022-06-30

Volume: 68

Issue: 2

Page Range: 3888-3895

Description:

No description provided

Open Access: Yes

DOI: 10.52091/EVIK-2022/2-3-HUN

Domain decomposition method with an interface preconditioner for frictionless contact problem

Lotfi Abdelhakim

Publication Name: Aip Conference Proceedings

Publication Date: 2008-10-22

Volume: 1048

Issue: Unknown

Page Range: 359-363

Description:

The present paper is concerned with the frictionless bilateral or unilateral contact problem between two elastic bodies. An algorithm is introduced to solve the resulting finite element system by a non-overlapping domain decomposition method. This technique enable us to transform the solution of the global problem to the solutions of the elasticity equations for each body separately and the solution of the Schur complement problem on the contact surface. The main goal of this work is the construction of the interface preconditioner for the Schur complement problem. The solution is obtained by using a successive approximation method. Finally, some numerical results of the proposed method are given. © 2008 American Institute of Physics.

Open Access: Yes

DOI: 10.1063/1.2990933

On the development of signatures for Artificial Intelligence applications

Claudiu Radu Pozna Peter Foldesi Radu Emil Precup Laszlo T. Koczy

Publication Name: IEEE International Conference on Fuzzy Systems

Publication Date: 2014-09-04

Volume: Unknown

Issue: Unknown

Page Range: 1304-1310

Description:

This paper illustrates developments of signatures for Artificial Intelligence (AI) applications. Since the signatures are data structures with efficient results in modeling of fuzzy inference systems and of uncertain expert systems, the paper starts with the analysis of the data structures used in AI applications from the knowledge representation and manipulation point of view. An overview on the signatures, on the operators on signatures and on classes of signatures is next given. Using the proto fuzzy inference system, these operators are applied in a new application of fuzzy inference system modeled by means of signatures and of classes of signatures.

Open Access: Yes

DOI: 10.1109/FUZZ-IEEE.2014.6891636