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Found 6374 publications

Application of a Novel Methodology for the Detection of Harmonic Vibration in the Acceleration-Time Functions of Vehicle Platforms

Renáta Pidl

Publication Name: Strojnicky Casopis Journal of Mechanical Engineering

Publication Date: 2022-11-01

Volume: 72

Issue: 2

Page Range: 139-148

Description:

In this paper, an attempt is made to determine whether Cepstrum analysis can be applied to detect pure harmonic sine waveform acceleration-time signals in a frequency sub-band from the acceleration-time function of vehicle load platforms. Based on Cepstrum evaluation of specific measurement results at different speeds and under different road conditions, the analysis reveals that no frequency band exhibits full-period pure sinusoidal excitation, which casts doubt regarding usuage of sinusoidal sliding frequency tests for package shaking tests.

Open Access: Yes

DOI: 10.2478/scjme-2022-0024

INVESTIGATION OF TRAFFIC INDUCED DYNAMIC RESPONSE OF A BRIDGE

Zoltán Major Péter Szalai Péter Horváth F. Hajdu Rajmund Kuti M. Brinissat Antal Apagyi Cs Papp

Publication Name: Strojnicky Casopis Journal of Mechanical Engineering

Publication Date: 2023-05-01

Volume: 73

Issue: 1

Page Range: 85-102

Description:

Bridges are special structures that provide a transport connection between areas divided by a physical barrier. Vehicles passing over bridges cause vibrations in the structural elements of the bridge, which can damage these structural elements over time. The aim of our research was to investigate the vibrations generated by vehicles on Hungary's first steel girder welded bridge, which was subjected to the maximum allowable load. In this paper, we describe the measurements we have carried out, analyse the results, present the vehicle-bridge interaction model we have constructed and the computer simulation we have carried out by using it. Our research results are intended to contribute to accident prevention and the safe operation of bridges.

Open Access: Yes

DOI: 10.2478/scjme-2023-0007

Cognitive and spiritual revolution of the tenth century - Constantine porphyrogenitus and his hidden world: Part II. the Great Monarch's hidden world in the great medieval artistic works

Peter Varlaki Péter Baranyi

Publication Name: 8th IEEE International Conference on Cognitive Infocommunications Coginfocom 2017 Proceedings

Publication Date: 2017-07-02

Volume: 2018-January

Issue: Unknown

Page Range: Unknown

Description:

The paper discusses, through a comparative hermeneutical microanalysis, identical and very similar representational (iconographic) and meaning systems of such great medieval art-works as the Limburg Staurotheke, Orthodox Metal Icons and the 'Archangel enamel pictures' of the Holy Crown of St Stephen of Hungary. The basis of the comparison is the discussed hidden mystical writings of the Great Monarch in part I of the paper.

Open Access: Yes

DOI: 10.1109/CogInfoCom.2017.8268294

Innovations in Offshore Wind: Reviewing Current Status and Future Prospects with a Parametric Analysis of Helical Pile Performance for Anchoring Mooring Lines

Ammar N. Alnmr Mais Mayassah

Publication Name: Journal of Marine Science and Engineering

Publication Date: 2024-07-01

Volume: 12

Issue: 7

Page Range: Unknown

Description:

This study examines the current status and future potential of the offshore wind sector. Offshore wind is pivotal in transitioning to a low-carbon society and meeting rising energy demands, despite being capital-intensive. The industry aims to develop larger-scale wind farms in deeper ocean locations, with projections indicating significant cost reductions. To explore deeper ocean areas, specialized foundations like floating platforms moored to the seabed are required. This study proposes helical piles anchored in the seabed as a method to secure mooring lines. Using Plaxis 3D, a parametric examination was conducted on helical piles with two plates: one fixed at the pile’s toe and the other varying in position between 0.5 and 13 m from the seabed surface. Load inclination angles (0, 20, 40, and 60 degrees) were used to simulate mooring line loads. Results indicate the optimal Zh/Z ratios for maintaining load-bearing capacity and stability: 0.12 (10 mm movements), 0.22 (25 mm), and 0.26 (50 mm) for small shaft diameters; and 0.34 (10 mm), 0.38 (25 mm), and 0.46 (50 mm) for large shaft diameters. These findings highlight the importance of specific load inclination angles based on shaft diameter and allowable movement for effective performance.

Open Access: Yes

DOI: 10.3390/jmse12071040

Hamiltonian-Based Control Approach with Pendulum Application

Claudiu Radu Pozna Áron Ballagi Radu Emil Precup

Publication Name: Saci 2024 18th IEEE International Symposium on Applied Computational Intelligence and Informatics Proceedings

Publication Date: 2024-01-01

Volume: Unknown

Issue: Unknown

Page Range: 593-598

Description:

The paper proposes a design method dedicated to control systems, which use a certain energy function (surface), called the Hamiltonian of the system. The plant requires, most of the time, the convergence at different fixed points and at the same time in different ways (different behaviors). This phenomenon is possible by modifying the initial energy surface. Modification of the energy surface can be achieved by external (generalized) forces. The formalism suggested in this paper allows the calculation of generalized forces and, finally, to obtain the mentioned changes.

Open Access: Yes

DOI: 10.1109/SACI60582.2024.10619844

On Enhancement of Efficiency of Three Kinds of Rectangular DRA Antennas by Optimizing Geometrical Properties

Hussein Turki Alateewe Szilvia Nagy

Publication Name: 2023 58th International Scientific Conference on Information Communication and Energy Systems and Technologies Icest 2023 Proceedings

Publication Date: 2023-01-01

Volume: Unknown

Issue: Unknown

Page Range: 65-68

Description:

DRA antennas have several favorable characteristics such as small size, low cost and desirable radiation pattern. These advantages make companies use this antenna in different fields in communication. Our aim is to enhance some properties of the rectangular antenna such as gain, bandwidth, S-parameter, VSWR and directivity. Therefore, three kinds of rectangular DRA antenna designs were selected and their geometrical and material parameters were systematically changed to enhance their performance. Also, the effect of adding more layers into the DRA design to get higher gain and to enhance the efficiency at frequency 28 GHz was studied. The designing and simulating of the DRA antenna were carried out by using the framework of CST.

Open Access: Yes

DOI: 10.1109/ICEST58410.2023.10187334

Path planning for mobile robots by bacterial memetic algorithm

János Botzheim Yuichiro Toda Naoyuki Kubota

Publication Name: IEEE Ssci 2011 Symposium Series on Computational Intelligence Riiss 2011 2011 IEEE Workshop on Robotic Intelligence in Informationally Structured Space

Publication Date: 2011-08-12

Volume: Unknown

Issue: Unknown

Page Range: 107-112

Description:

The goal of the path planning problem is to determine an optimal collision-free path between a start and a target point for a mobile robot in an environment surrounded by obstacles. This problem belongs to the group of hard optimization problems which can be approached by modern optimization techniques such as evolutionary algorithms. In this paper the bacterial memetic algorithm is proposed for path planning of a mobile robot. The representation used in the paper fits well to the algorithm. Memetic algorithms combine evolutionary algorithms with local search heuristics in order to speed up the evolutionary process. The bacterial memetic algorithm applies the bacterial operators instead of the genetic algorithm's crossover and mutation operator. One advantage of these operators is that they easily can handle individuals with different length. The proposed algorithm is tested in real environment. © 2011 IEEE.

Open Access: Yes

DOI: 10.1109/RIISS.2011.5945787

Emerging Importance of Supply Chain Attitudes

Péter Németh Andrea Rankl

Publication Name: Chemical Engineering Transactions

Publication Date: 2024-01-01

Volume: 114

Issue: Unknown

Page Range: 1015-1020

Description:

The nature of relationships within supply chains and understanding the dynamics of interactions between the supply chain members are key factors in today's globalised economy, where speed, efficiency and flexibility in the flow of goods and information are crucial. Improving the efficiency of supply chains and managing their inherent risks has become one of today's most pressing economic challenges, directly affecting not only the competitiveness of companies but also the achievement of sustainability goals. To better understand those relations among companies, a deeper understanding of the attitudes of the different supply chains is inevitable. This paper is the inaugural work towards this research. Analysing attitudes towards relationships within supply chains is a critical aspect of understanding interactions between companies and the performance of networks. Digital transformation, depth of customer integration, relationship engagement, and efficiency in joint problem-solving are factors that have a significant impact on supply chain flexibility and performance. To achieve sustainability and resilience, companies need to adopt adaptive and proactive strategies that can address environmental, social and economic challenges and anticipate and respond to future market changes. The projected aim is to understand the attitude of the organisation as an independent entity, not as an attitude generated by the individuals of the management.

Open Access: Yes

DOI: 10.3303/CET24114170

DETECTION PROCESS OF ENERGY LOSS IN ELECTRIC RAILWAY VEHICLES

Szabolcs Fischer Szabolcs Kocsis Szurke

Publication Name: Facta Universitatis Series Mechanical Engineering

Publication Date: 2023-04-01

Volume: 21

Issue: 1

Page Range: 81-99

Description:

The paper deals with the detection process of energy loss in electric railway hauling vehicles. The importance of efficient energy use in railways and cost-effective rail transport tendency toward regenerative braking energy are considered. In addition, the current situation and improvement opportunities to achieve efficient energy use are examined. Seven measurement series were performed with scheduled Railjet trains between Hegyeshalom and Győr railway stations in Hungary. This railway section is related to the Hungarian State Railways' No. 1 main railway line (between Budapest-Kelenföld and Hegyeshalom state board), which is a part of the international railway line between Budapest and Vienna (capitals of Hungary and Austria, respectively). This double-track, electrified railway line with traditional ballasted superstructures and continuously welded rail tracks is important due to the international passenger and freight transport between Germany, Austria, and Hungary. The value of the regenerative braking energy can be even 20-30% of the total consumed energy. This quite enormous untapped energy can be used for several aims, e.g., for comfort energy demand (air conditioning, heating-cooling, lighting, etc.) or energy-intensive starts. The article also investigates the optimization of regenerative braking energy by seeking the energy-waste locations and the reasons for the significant consumption. The train operator's driving style and habit have been identified as one of the main reasons. Furthermore, train driver assistance systems are recommended to save energy, which is planned for future research.

Open Access: Yes

DOI: 10.22190/FUME221104046F