Search in Publications

Found 6515 publications

Effect of junction type on the vibroacoustic response of a system of plates

Dániel Feszty Marcell Treszkai

Publication Name: Proceedings of Inter Noise 2021 2021 International Congress and Exposition of Noise Control Engineering

Publication Date: 2021-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

Modelling of junctions is one of the most challenging tasks in vibroacoustics, especially for Statistical Energy Analysis (SEA), where the results heavily depend on the damping (DLF) and coupling loss factors (CLF). Also, it is an interesting question to determine that to what extent does the DLF or CLF contribute to the overall vibroacoustic characteristics of a structure? The aim of this paper is to investigate via measurements and SEA simulations the effect of the ratio of DLF and CLF on the response of a system for various junctions, such as riveting, bolting, line and point welding, between two steel plates. Loss matrices are determined experimentally by the Power Injection Method in the 200-1600 Hz frequency range. The simulation was performed in the ESI VA One software by using its analytical CLF formulations and compared to experimental data. For the reference case, a bended plate structure was considered, representing an ideal junction between two subsystems. This was equipped with damping foils to ensure the same weight and then compared to the results from other joints. Results showed that increasing the CLF could be more effective than focusing on increasing the DLF.

Open Access: Yes

DOI: 10.3397/IN-2021-2565

A Localized Multi-Level Method of Fundamental Solutions Applied to Steady Heat Transfer Problems

Csaba Gáspár

Publication Name: Key Engineering Materials

Publication Date: 2025-01-01

Volume: 1033

Issue: Unknown

Page Range: 93-104

Description:

A special localization technique is presented for solving steady heat transfer problems, in which the thermal conductivity may depend on space variables. The original problem is split into several subproblems defined on much smaller subdomains. The subproblems are solved using the Method of Fundamental Solutions, which is a truly meshless method. This leads to a Seidel-like iterative technique, which mimics the classical Schwarz overlapping method. The problems associated with large, dense and ill-conditioned matrices are avoided. The method is embedded into a multi-level context, which significantly reduces the computational complexity.

Open Access: Yes

DOI: 10.4028/p-NN3rBx

A long-distance runner in the colours of two clubs. Kálmán Kulcsár is eighty

Károly Varga

Publication Name: Tarsadalomkutatas

Publication Date: 2008-01-01

Volume: 26

Issue: 2

Page Range: 131-141

Description:

We greet a scholar, politician and researcher of major format on the occasion of his eightieth birthday. During his life full of work Kálmán Kulcsár has introduced new disciplines in Hungary, as a science politician he made major efforts for the establishment and consolidation of the institutions of sociology and political science. As a professor he taught the theory of the state and of law, and the sociology of law to generations, as a politician and Minister of Justice he did a great deal for the legal preparation of the change of the political system. As a diplomat he represented our country in Ottawa to the satisfaction of all. Above all he is an extremely prolific researcher who publishes his interesting writings to this day. His interest extends over theoretical questions to the development of individual societies, from Europe to Asia, his profundity is legendary; his clear-cut style makes his writings enjoyable to the reader. We hope that he would surprise his associates, disciples and the Hungarian academic life with several new works to come. © 2008, Akadémiaí Kiadó.

Open Access: Yes

DOI: 10.1556/Tarskut.26.2008.2.1

Simulations of poroelastic materials in a complex acoustic system using frequency-dependent parameters in the mid-frequency range

Dániel Feszty Janos Kun

Publication Name: Proceedings of Inter Noise 2021 2021 International Congress and Exposition of Noise Control Engineering

Publication Date: 2021-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

Efficiency requirements prompt manufacturers to develop ever lighter acoustic packages in vehicles. Poroelastic materials are essential to achieve the desired interior noise level targets and thus the simulation of their effects is of utmost importance in NVH analyses. However, it is challenging to achieve good validation between finite element method (FEM) based simulation results and measurements in the mid-frequency range (400-1000 Hz). One possible reason could be the lack of using frequency-dependent Biot-paremeters describing the poroelastic materials (PEM) characteristics of trims. The present research aims to employ frequency-dependent Biot-parameters for the PEM materials to investigate the acoustic response of a scaled car-like steel structure composed of flat plates and U-section stiffeners enclosing an air cavity. Porous acoustic material is applied to the walls of the cavity. The focus of the study is to understand the effect of applying frequency-dependent Young's modulus and damping values for the PEM parameters in the 100-1000 Hz range. Simulation results obtained from ESI VPS FEM solver are compared with measurements, with particular focus on the interior sound pressure levels. The simulation methodology, including discretization techniques, structural damping and fluid damping applications are described in detail.

Open Access: Yes

DOI: 10.3397/IN-2021-2869

On the topology of two dimensional generalized cell systems

Ibolya Zsoldos J. Janik Tamás Réti

Publication Name: Recent Advances in Multidisciplinary Applied Physics

Publication Date: 2005-12-01

Volume: Unknown

Issue: Unknown

Page Range: 559-564

Description:

No description provided

Open Access: Yes

DOI: 10.1016/B978-008044648-6.50085-9

First Report of Saffron Latent Virus in Crocus sativus from Hungary

László Palkovics Réka Sáray János Ágoston Dóra Pinczés Asztéria Almási Katalin Salánki

Publication Name: Plant Disease

Publication Date: 2024-02-01

Volume: 108

Issue: 2

Page Range: 540

Description:

No description provided

Open Access: Yes

DOI: 10.1094/PDIS-09-23-1765-PDN

Progress in diagnostics of the COMPASS tokamak

V. Weinzettl R. Paprok A. Podolnik J. Seidl M. Peterka P. Vondracek M. Stano T. Krizsanoczi P. Bilkova M. Dimitrova N. Vianello M. Sos M. Tomes M. Varavin J. Varju M. Hron J. Zajac F. Zacek M. Berta T. Markovic A. Devitre O. Grover M. Komm P. Hacek E. Gauthier E. Matveeva J. Mlynar D. Naydenkova K. Kovarik M. Rabinski J. Adamek J. Horacek J. Stockel R. Pánek R. Dejarnac J. Havlicek A. Havranek R. Gomes M. Vlainic A. Silva S. Zoletnik P. Bohm J. Cavalier O. Ficker M. Imrisek G. Anda D. Dunai D. Refy T. Pereira Tsv Popov D. Sarychev G. P. Ermak J. Zebrowski M. Jakubowski J. Krbec S. Nanobashvili M. Spolaore O. Bogar K. Mitosinkova K. Malinowski D. Fridrich J. P. Gunn

Publication Name: Journal of Instrumentation

Publication Date: 2017-12-07

Volume: 12

Issue: 12

Page Range: Unknown

Description:

The COMPASS tokamak at IPP Prague is a small-size device with an ITER-relevant plasma geometry and operating in both the Ohmic as well as neutral beam assisted H-modes since 2012. A basic set of diagnostics installed at the beginning of the COMPASS operation has been gradually broadened in type of diagnostics, extended in number of detectors and collected channels and improved by an increased data acquisition speed. In recent years, a significant progress in diagnostic development has been motivated by the improved COMPASS plasma performance and broadening of its scientific programme (L-H transition and pedestal scaling studies, magnetic perturbations, runaway electron control and mitigation, plasma-surface interaction and corresponding heat fluxes, Alfvenic and edge localized mode observations, disruptions, etc.). In this contribution, we describe major upgrades of a broad spectrum of the COMPASS diagnostics and discuss their potential for physical studies. In particular, scrape-off layer plasma diagnostics will be represented by a new concept for microsecond electron temperature and heat flux measurements - we introduce a new set of divertor Langmuir and ball-pen probe arrays, newly constructed probe heads for reciprocating manipulators as well as several types of standalone probes. Among optical tools, an upgraded high-resolution edge Thomson scattering diagnostic for pedestal studies and a set of new visible light and infrared (plasma-surface interaction investigations) cameras will be described. Particle and beam diagnostics will be covered by a neutral particle analyzer, diagnostics on a lithium beam, Cherenkov detectors (for a direct detection of runaway electrons) and neutron detectors. We also present new modifications of the microwave reflectometer for fast edge density profile measurements.

Open Access: Yes

DOI: 10.1088/1748-0221/12/12/C12015

The Cognitive Mobility Concept

Peter Baranyi Máté Zöldy

Publication Name: Infocommunications Journal

Publication Date: 2023-01-01

Volume: 2023

Issue: Unknown

Page Range: 35-40

Description:

Mobility is the engine of our society in the third millennium. Rapid technical development makes it possible to increase cognitive ability in various fields; mobility is one of the most affected. Mobility has become a multidimensional concept in our interpretation; in addition to transportation, it also appears in the digital space, among other dimensions. The 21st century has brought unprecedented challenges, such as the covid-19 virus and the Russian war in Ukraine. These highlight bottlenecks in mobility systems and prompted us to explore the concept of cognitive mobility. This paper intends to refine the CogMob approach, which co-manages human and machine capabilities in mobility. New achievements within CogMob's domain match the new challenges of war and viruses. This article aims to outline the field of cognitive mobility. It presents CogMob's definition and examples that clarify the combinations of cognitive levels of different mobilities.

Open Access: Yes

DOI: 10.36244/ICJ.2023.SI-IODCR.6

Comparative 3-dimensional visualization of the equine petrosal bone

Petneházy Örs Rácz Bence Pomsár Miklós Baksa Gábor Kozma István Czeibert Kálmán

Publication Name: Magyar Allatorvosok Lapja

Publication Date: 2018-01-01

Volume: 140

Issue: 12

Page Range: 737-744

Description:

Background: The petrosal bone is one of the smallest and most complex among the bones of the equine skull. Its irregular surface, several projections and channels, and hidden inner structures make its visualization challenging. Textbooks usually show this bone on different drawings and photographs, where the structures' relationship and their spatial organization cannot be properly understood. Objectives: We wanted to create high-resolution surface models of certain petrosal bone structures in order to study them separately or in connection with the originál one. Materials and methods: First we captured photos from a skull and its left petrosal bone. The isolated bone was scanned with a microfocus CT (FOV: 1024x1024, size of a voxel: 0.06 x 0.06 x 0.06 mm) and DICOM images were exported. Image volume was analysed with FEI Amira 6.0 for LifeSciences software; during seg-mentation individually labelled fields were generated to the following structures: surface model of the petrosal bone, malleus, incus, os lenticulare, stapes, inner ear and the channel of the facial nerve. 3-dimensional models were made from the label fields, and after refinement STL (stereolithography) models were made. Results and discussion: Changing the opacity of the surface models gave a unique possibility to compare the inner structure of the same bone seen on photographs and on the 3D-model in different aspects. Enlarging and labelling the inner ear and the auditory ossicles were also performed. In order to show the outer and the inner structure more interactively, three short video animations were created which present the outer aspects, the middle ear cavity, the inner ear and the channel of the facial nerve (like a virtual endoscopy). Finally, the STL-model of the auditory ossicles associated with the inner ear was 3D-printed and colorized according to the surface models. In conclusion, the 3D-visualization (modelling, augmented and virtual reality, 3D-printing) can be an immense aid not only in the educational, but also in clinical and research fields.

Open Access: Yes

DOI: DOI not available