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Tytuł:
Testing of the three axis magnetometers for measurements of the earths magnetic field
Autorzy:
Szewczyk, R.
Salach, J.
Bieńkowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/385198.pdf
Data publikacji:
2009
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
magnetic sensors
Helmholtz coils
calibration
Opis:
The paper presents experimental setup for testing of the three axis magnetoresisitive magnetometers for measurements of the magnetic field within the range of Earth's magnetic field. Measuring setup integrates three axis Helmholtz coils controlled by the specialized current source. The accuracy of magnetic field generated by the Helmholtz coils is up to 0.6% for the one direction. Presented experimental setup can be also applied for investigation and calibration of the other magnetometers utilizing magnetoresistive, Hall or fluxgate sensors.
Źródło:
Journal of Automation Mobile Robotics and Intelligent Systems; 2009, 3, 4; 96-98
1897-8649
2080-2145
Pojawia się w:
Journal of Automation Mobile Robotics and Intelligent Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Acoustic Scattering of 3D Complex Systems Having Random Rough Surfaces by Scalar Integral Equations
Autorzy:
Guel-Tapia, J. A.
Villa-Villa, F.
Mendoza-Suárez, A.
Pérez-Aguilar, H.
Powiązania:
https://bibliotekanauki.pl/articles/178120.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
integral equations
Helmholtz equation
acoustic scattering
Opis:
We propose a numerical surface integral method to study complex acoustic systems, for interior and exterior problems. The method is based on a parametric representation in terms of the arc’s lengths in curvilinear orthogonal coordinates. With this method, any geometry that involves quadric or higher order surfaces, irregular objects or even randomly rough surfaces can be considered. In order to validate the method, the modes in cubic, spherical and cylindrical cavities are calculated and compared to analytical results, which produced very good agreement. In addition, as examples, we calculated the scattering in the far field and the near field by an acoustic sphere and a cylindrical structure with a rough cross-section.
Źródło:
Archives of Acoustics; 2016, 41, 3; 461-472
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Incorporation of Resonators Into Plenum Window
Autorzy:
Lee, H. M.
Haris, A.
Lim, K. M.
Xie, J.
Lee, H. P.
Powiązania:
https://bibliotekanauki.pl/articles/176744.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
plenum window
Helmholtz resonators
noise pollution
ventilation
Opis:
A plenum window with incorporation of Helmholtz resonators in between two glass panes was tested in a reverberation room. The effects of jagged flap on reducing strength of diffracted sound was also investigated in the present studies where white, traffic and construction noises were examined Turing each set of experiment. When the noise source was located at the central line of the plenum window, the plenum window with Helmholtz resonators was able to mitigate 8.5 dBA, 8.9 dBA and 8.2 dBA of white, traffic and construction noises, respectively, compared with the case of without window. These amounts of noises that attenuated by the plenum window were slightly higher than the case where noise source was diverged 30° away from the plenum window. The effects of jagged flaps on the acoustical performance of the plenum window were negligible. The Helmholtz resonators had the best performance in the frequency region between 900 Hz to 1300 Hz where in this frequency range, the plenum window with Helmholtz resonators was able to attenuate additional 1.7 dBA, 1.9 dBA and 1.6 dBA of white, traffic and construction noises, respectively, compared with the case of without resonators.
Źródło:
Archives of Acoustics; 2018, 43, 4; 739-746
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Methods for Classification of Tactile Patterns in General Position by Helmholtzs Equation
Autorzy:
Volf, J.
Dvorak, M.
Vlcek, J.
Powiązania:
https://bibliotekanauki.pl/articles/384955.pdf
Data publikacji:
2008
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
pattern recognition
Helmholtz's equation
tactile image
tactile information
Opis:
This paper describes new and original methods of tactile pattern recognition in general position applying the solution of Helmholtz's equation for a tactile transducer. Three groups of methods have been formed, based on: (a) calculation of the A matrix eigen value, with the matrix being formed either from the whole pattern, or from the limit points; (b) the scalar characteristic distribution of the components of the pattern's A matrix; (c) the geometrical properties of the A matrix of the pattern. The patterns have been classified into five groups.
Źródło:
Journal of Automation Mobile Robotics and Intelligent Systems; 2008, 2, 4; 59-63
1897-8649
2080-2145
Pojawia się w:
Journal of Automation Mobile Robotics and Intelligent Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of the CRLC models describing the Helmholtz type cells for the nondestructive photoacoustic spectroscopy
Autorzy:
Chrobak, Ł. B.
Maliński, M. A.
Powiązania:
https://bibliotekanauki.pl/articles/221397.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
nondestructive testing
photoacoustic spectroscopy
photoacoustic cells
Helmholtz cells
Opis:
The photoacoustic cell is the heart of the nondestructive photoacoustic method. This article presents a new simple lumped-components CRLC model of the Helmholtz type photoacoustic cell. This model has been compared with the well known literature models describing the Helmholtz type cells for photoacoustic spectroscopy. Experimental amplitude and phase frequency data obtained for the two photoacoustic cells have been presented and interpreted in a series of models. Results of the fitting of theoretical curves, obtained in these models, to the experimental data have been shown and discussed.
Źródło:
Metrology and Measurement Systems; 2014, 21, 3; 545-552
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mesh-free approach to Helmholtz equation based on radial basis functions
Autorzy:
Kowalczyk, P.
Mrozowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/309385.pdf
Data publikacji:
2005
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
Helmholtz equation
radial basis functions
meshfree method
cylindrical waveguides
Opis:
Recently, a radial basis functions (RBFs) method, which was originally proposed for interpolation problems, has been developed and applied to solve partial differential equations and eigenproblems. Properties of that method (meshfree algorithm) allows one to use it in many areas, including electromagnetics. In this paper the mesh-free RBF method for solving Helmholtz equation was applied and a new adaptive algorithm for defining the set of interpolation centers was proposed. Using the proposed approach the cutoff wavelengths and the field distribution in cylindrical waveguides of arbitrary cross-section were calculated with a high accuracy.
Źródło:
Journal of Telecommunications and Information Technology; 2005, 2; 71-74
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the Photoacoustic Helmholtz Resonator with Conical-Ended Duct
Autorzy:
Suchenek, M.
Powiązania:
https://bibliotekanauki.pl/articles/227182.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Helmholtz resonator
influence of duct shape
conical duct model
Opis:
The acoustic properties of the photoacoustic Helmholtz cell can be improved by conical modification of the duct ends. The cone profile of the duct ends was studied, and according to the previous work, not all modifications of the parameters provide an increase of the Q-factor of the resonator. The aim of this work is to investigate the influence of the conical modification of the duct using a step-approximated model.
Źródło:
International Journal of Electronics and Telecommunications; 2017, 63, 2; 123-126
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transmission problems for the Helmholtz equation for a rectilinear-circular lune
Autorzy:
Denysenko, V.
Powiązania:
https://bibliotekanauki.pl/articles/255476.pdf
Data publikacji:
2007
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
Helmholtz equation
transmission problem
infinite system of linear algebraic equations
Opis:
The question related to the construction of the solution of plane transmission problem for the Helmholtz equation in a rectilinear-circular lune is considered. An approach is proposed based on the method of partial domains and the principle of reflection for the solutions of the Helmholtz equation through the segment.
Źródło:
Opuscula Mathematica; 2007, 27, 2; 197-203
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An alternating current calibration method for Helmholtz coil constant based on orthogonal calculation principle
Autorzy:
Zhang, Kuankuan
Cao, Mingxing
He, Jian
Gong, Wenjie
Huang, Yunhua
Powiązania:
https://bibliotekanauki.pl/articles/27311758.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
Helmholtz coils constant
alternating current method
induction voltage
orthogonal calculations
Opis:
The Helmholtz coil constant (ℎ) is a crucial standard in magnetic moment measurement devices for permanent magnet materials. To overcome the problem of low accuracy of the direct-current (DC) calibration method, this study used a constant sinusoidal current in the Helmholtz coil and measured the induced voltage of the detection coil with known coil turns and coil area. Subsequently, the ℎ was calculated. The noise signal deduction rate in the induction voltage of the detection coil was greater than 99%, its influence on the induction voltage is less than 0.005%, and the repeatability of the calibration results is 0.003% (1). The results reveal that the alternating current (AC) method and orthogonal calculation (OC) can accurately measure the valid values of the voltage signal under the influence of the spatial stray field during the calibration of ℎ.
Źródło:
Metrology and Measurement Systems; 2023, 30, 3; 549--561
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Noise Elimination of a Multi-tone Broadband Noise with Hybrid Helmholtz Mufflers Using a Simulated Annealing Method
Autorzy:
Chiu, M-C.
Powiązania:
https://bibliotekanauki.pl/articles/176674.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
multiple tones
hybrid
Helmholtz
four-pole transfer matrix method
SA method
Opis:
Noise control is essential in an enclosed machine room where the noise level has to comply with the occupational safety and health act. In order to overcome a pure tone noise with a high peak value that is harmful to human hearing, a traditional reactive muffler has been used. However, the traditional method for designing a reactive muffler has proven to be time-consuming and insufficient. In order to efficiently reduce the peak noise level, interest in shape optimization of a Helmholtz muffler is coming to the forefront. Helmholtz mufflers that deal with a pure tone have been adequately researched. However, the shape optimization of multi-chamber Helmholtz mufflers that deal with a broadband noise hybridized with multiple tones within a constrained space has been mostly ignored. Therefore, this study analyzes the sound transmission loss (STL) and the best optimized design for a hybrid Helmholtz muffler under a space- constrained situation. On the basis of the plane wave theory, the four-pole system matrix used to evaluate the acoustic performance of a multi-tone hybrid Helmholtz muffler is presented. Two numerical cases for eliminating one/two tone noises emitted from a machine room using six kinds of mufflers (muffler AF) is also introduced. To find the best acoustical performance of a space-constrained muffler, a numerical assessment using a simulated annealing (SA) method is adopted. Before the SA operation can be carried out, the accuracy of the mathematical model has been checked using the experimental data. Eliminating a broadband noise hybridized with a pure tone (130 Hz) in Case I reveals that muffler C composed of a one- chamber Helmholtz Resonator and a one-chamber dissipative element has a noise reduction of 54.9 (dB). Moreover, as indicated in Case II, muffler F, a two-chamber Helmholtz Resonator and a one-chamber dissipative element, has a noise reduction of 69.7 (dB). Obviously, the peak values of the pure tones in Case I and Case II are efficiently reduced after the muffler is added. Consequently, a successful approach in eliminating a broadband noise hybridized with multiple tones using optimally shaped hybrid Helmholtz mufflers and a simulated annealing method within a constrained space is demonstrated.
Źródło:
Archives of Acoustics; 2012, 37, 4; 489-498
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dirichlet/Dirichlet and Dirichlet/Dirichlet-Neumann/Neumann non-overlapping iterative domain decomposition methods
Autorzy:
Kubacki, S.
Bogusławski, A.
Powiązania:
https://bibliotekanauki.pl/articles/1933184.pdf
Data publikacji:
2008
Wydawca:
Politechnika Gdańska
Tematy:
non-overlapping domain decomposition method
parallel computing
spectral methods
Helmholtz equation
Opis:
A new iterative non-overlapping domain decomposition method is proposed for solving the one- and two-dimensional Helmholtz equation on parallel computers. The spectral collocation method is applied to solve the Helmholtz equation in each subdomain based on the Chebyshev approximation, while the patching conditions are imposed at the interfaces between subdomains through a correction, being a linear function of the space coordinates. Convergence analysis is performed for two applications of the proposed method (DDLC and DDNNLC algorithms - the meaning of these abbreviations is explained below) based on the works of Zanolli and Funaro et al. Numerical tests have been performed and results obtained using the proposed method and other iterative algorithms have been compared. Parallel performance of the multi-domain algorithms has been analyzed by decomposing the two-dimensional domain into a number of subdomains in one spatial direction. For the one-dimensional problem, convergence of the iteration process was quickly obtained using the proposed method, setting a small value of the ? constant in the Helmholtz equation. Another application of the proposed method may be an alternative to other iterative schemes when solving the two-dimensional Helmholtz equation.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2008, 12, 1-2; 85-104
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Acoustic System of Determining the Instantaneous Volume of the Blood Part of the Ventricular Assist Device POLVAD-EXT
Autorzy:
Konieczny, G.
Pustelny, T.
Opilski, Z.
Gawlikowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/176599.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
acoustic Helmholtz’s
resonator
blood volume estimation
VAD
ventricular assist device
Opis:
The paper presents the results of investigations concerning the noninvasive method of estimating the actual volume of the blood chamber of the POLVAD-EXT type ventricular assist device (VAD) during its operation. The proposed method is based on the principle of Helmholtz’s acoustic resonance. Both the theory, main stages of the development of the measurement method as well as the practical implementation of the proposed method in the physical model of the POLVAD-EXT device are dealt with. The paper contains the results of static measurements by means of the proposed method (conducted at the Department of Optoelectronics, Silesian University of Technology) as well as the dynamic measurements taken at the Foundation of Cardiac Surgery Development (Zabrze, Poland) with the professional model of the human cardiovascular system. The results of these measurements prove that the proposed method allows to estimate the actual blood chamber volume with uncertainties below 10%.
Źródło:
Archives of Acoustics; 2014, 39, 4; 541-548
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kalibracja małej anteny pętlowej
The calibration of small loop antenna
Autorzy:
Szczupak, Paweł
Powiązania:
https://bibliotekanauki.pl/articles/2015053.pdf
Data publikacji:
2020
Wydawca:
Politechnika Rzeszowska im. Ignacego Łukasiewicza. Oficyna Wydawnicza
Tematy:
antena pętlowa
kalibracja anteny
cewka Helmholtza
loop antenna
antenna calibration
Helmholtz coil
Opis:
W artykule przedstawiono przykłady kalibracji małej anteny pętlowej, która może być wykorzystana do pomiarów składowej magnetycznej pola elektromagnetycznego. Źródłem takiego pola może być na przykład wyładowanie atmosferyczne. Istnieje wiele metod kalibracji anteny pętlowej. Poniżej przedstawiono dwie - przy użyciu skalibrowanej anteny probierczej o znanych parametrach, oraz używając jednorodnego pola magnetycznego wytworzonego przy pomocy cewki Helmholtza. Pomiary przy użyciu pierwszej metody zostały przeprowadzone w komorze bezodbiciowej laboratorium kompatybilności elektromagnetycznej.
The article presents examples of calibration of a small loop antenna, witch can be used to measure the magnetic component of the electromagnetic field. The source of such a field may be, for example, lightning. There are many methods of calibration a loop antenna. Two of them are presented below - using test antenna with is calibrated and with known parameters, and using a homogenous magnetic field generated inside Helmholtz coil. Measurements using the first method were carried out in the anechoic chamber of the EMC laboratory.
Źródło:
Zeszyty Naukowe Politechniki Rzeszowskiej. Elektrotechnika; 2020, 38 [301], 1-2; 109-116
0209-2662
2300-6358
Pojawia się w:
Zeszyty Naukowe Politechniki Rzeszowskiej. Elektrotechnika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the robustness of the topological derivative for Helmholtz problems and applications
Autorzy:
Leugering, Günter
Novotny, Antonio André
Sokolowski, Jan
Powiązania:
https://bibliotekanauki.pl/articles/2183490.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
topological derivative
shape optimization
inverse problems
Helmholtz problem
numerical methods
complex variables
Opis:
We consider Helmholtz problems in two and three dimensions. The topological sensitivity of a given cost function J(uɛ) with respect to a small hole Bɛ around a given point x0ɛ ∈ Bɛ ⊂ Ω depends on various parameters, like the frequency k chosen or certain material parameters or even the shape parameters of the hole Bɛ. These parameters are either deliberately chosen in a certain range, as, e.g., the frequencies, or are known only up to some bounds. The problem arises as to whether one can obtain a uniform design using the topological gradient. We show that for 2-d and 3-d Helmholtz problems such a robust design is achievable.
Źródło:
Control and Cybernetics; 2022, 51, 2; 227--248
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of Novel method of spherical aberration correction for enhanced spherical hybrid reflector antennas
Badanie nowej metody korekcji aberacji sferycznej dla wzmocnionych sferycznych anten hybrydowych
Autorzy:
Ponomarev, O. P.
Powiązania:
https://bibliotekanauki.pl/articles/118542.pdf
Data publikacji:
2010
Wydawca:
Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:
spherical aberration
hybrid reflector antennas
Helmholtz equation
aberracja sferyczna
anteny hybrydowe
równanie Helmholtza
Źródło:
Zeszyty Naukowe Wydziału Elektroniki i Informatyki Politechniki Koszalińskiej; 2010, 2; 77-92
1897-7421
Pojawia się w:
Zeszyty Naukowe Wydziału Elektroniki i Informatyki Politechniki Koszalińskiej
Dostawca treści:
Biblioteka Nauki
Artykuł
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