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Wyszukujesz frazę "Hydroacoustics" wg kryterium: Temat


Tytuł:
Hydroacoustics waves direct-of-arrival estimation using music algorithm - simulations results
Autorzy:
Żak, A.
Powiązania:
https://bibliotekanauki.pl/articles/332842.pdf
Data publikacji:
2009
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
music algorithm
hydroacoustics waves
hydroacoustics
Opis:
Paper presents simulations results of hydroacoustics waves' direction-of-arrival estimation using MUSIC algorithm. Firstly, the research problem is formulated by general description of studied case and release of simplifying assumption. Next the used to direct-of-arrival estimation MUSIC algorithm was discussed. The mathematical formulations, algorithm of calculation and some computational issues were presented. At the end of the paper the simulations results of estimation of direction-of-arrival using MUSIC algorithm for hypothetical situation were presented.
Źródło:
Hydroacoustics; 2009, 12; 249-256
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The examination of position of ships noises sources based on hydroacoustics method
Autorzy:
Listewnik, K.
Powiązania:
https://bibliotekanauki.pl/articles/331584.pdf
Data publikacji:
2008
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
hydroacoustics method
ship’s noises sources
hydroacoustics
Opis:
The paper presents the experimental research associated with the transmission of acoustic energy generated by moving ship into the water. The paper present the methodology of evaluations acoustics energy from the mechanisms of ship into the water environment. For that purpose the research of noise distribution over ship's hull were conducted along with the hydroacoustic field. The hull is source of waves of complex surface shape inducing waves of different amplitudes and phases depending on the position of ship's machinery. As a result of the hull vibrations generated wave distribution depending on the primary sources, as the main propulsion units, generators or other mechanisms. This research allowed to determine position of the main noises' sources of acoustics energy of machinery and propulsion system depending on class of ships.
Źródło:
Hydroacoustics; 2008, 11; 247-253
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Contribution of the IMS global network of hydroacoustic stations for monitoring the CTBT
Autorzy:
Bitnner, P.
Jonathan, E.
Villarroel, M.
Powiązania:
https://bibliotekanauki.pl/articles/331513.pdf
Data publikacji:
2008
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
CTBT
IMS
hydroacoustics
Opis:
The International Monitoring System (IMS) of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) Preparatory Commission, in Vienna operates a global network of 321 monitoring stations and 16 radionuclide laboratories that monitors the earth for evidence of nuclear explosions within the atmosphere, underwater and underground. The IMS uses a network of four verification technologies: seismic, hydroacoustic, infrasound and radionuclide. All the data recorded by the IMS network are transmitted to the International Data Centre (IDC) of the CTBTO in Vienna. The data are then received, processed, resulting data and products distributed and archived by the IDC. This study will give an overview of the contribution of the IMS hydroacoustic network and will highlight that for areas not well covered with the seismic network this part of the IMS can be very valuable for detecting events, improving the location obtained from the seismic network and providing information about the nature of sources.
Źródło:
Hydroacoustics; 2008, 11; 19-26
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of the underwater noise produced by ships by means of intensity method
Autorzy:
Kozaczka, E.
Domagalski, J.
Gloza, I.
Powiązania:
https://bibliotekanauki.pl/articles/258726.pdf
Data publikacji:
2010
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
energy
propagation
hydroacoustics
Opis:
This paper presents results of research on spectral structure of underwater noise acoustic field radiated into water by selected ships moving in shallow waters. Underwater acoustic field of ships in motion is associated with acoustic activity of ship mechanisms and equipment under work. Vibration energy radiated by the mechanisms and devices is transmitted by ship structural elements to surrounding water where it is propagated in the form of acoustic waves of a wide frequency band. In this paper are presented results of the research on propagation of energy of acoustic waves in the near fiel, obtained from acoustic pressure measurements by means of two sensors located close to each other.
Źródło:
Polish Maritime Research; 2010, 3; 26-36
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identification of hydroacoustic wave sources of ship in motion
Autorzy:
Kozaczka, E.
Domagalski, J.
Powiązania:
https://bibliotekanauki.pl/articles/259355.pdf
Data publikacji:
2010
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
identification
propagation
hydroacoustics
Opis:
This paper deals with results of identification tests of acoustic field spectrum of underwater noise generated by ship in motion. The field is connected with acoustic activity of ship mechanisms and devices in operation. Vibration energy generated by the mechanisms and devices is transferred through ship structural elements to surrounding water where it propagates in the form of acoustic waves of a broad band of frequencies. In the publication results of identification tests of underwater noise generated by a ship in motion, are presented.
Źródło:
Polish Maritime Research; 2010, 4; 64-71
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identification of hydro-acoustic waves emitted from floating units during mooring tests
Autorzy:
Kozaczka, E.
Domagalski, J.
Grelowska, G.
Gloza, I.
Powiązania:
https://bibliotekanauki.pl/articles/260463.pdf
Data publikacji:
2007
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
identification
propagation
hydroacoustics
Opis:
Measurements of hydro-acoustic noise emitted from vessels are a.o. a subject of the tests carried out in the control measurement ranges of the Navy. The measurements are performed both on anchored and floating vessels. Acoustic field of vessels is changing along with their speed changing and is associated with acoustic activity of wave sources installed in vessel’s hull (main engines, electric generating sets, reduction gears, pumps, shaft-lines, piping, ventilating ducts etc) as well as hydro-dynamic sources such as screw propellers and water flow around the hull [5, 7]. Vibration energy generated by the onboard devices is transferred through ship structural elements to water where it propagates in the form of hydro-acoustic waves of a wide frequency band.
Źródło:
Polish Maritime Research; 2007, 4; 40-46
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Theoretical problems of the wideband sonar time-spatial filtration
Autorzy:
Janowski, T.
Kotłowski, A.
Porosińska, E.
Powiązania:
https://bibliotekanauki.pl/articles/331819.pdf
Data publikacji:
2003
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
wideband sonar
hydroacoustics
Opis:
The paper presents the synthesis of the time-spatial matched filtration algorithm. First part specifies base for the algorithm-input data. Successively, the matched filtration for continuous junction is depicted. This leads to the canonical form of the time-spatial filter. Consecutively, the decomposition into series connection of the matched and spatial filtration is realized. The next step is the signals approximation by Fourier series due to equivalence between approximation and interpolation on uniformly distributed discrete sampIes. The equation of the spatial filtration - in frequency domain - results from this mathematical operations. Application of the Bluestein's method to solve this equation provides to the final algorithm version. Advantages of the developed algorithm are presented in conclusions.
Źródło:
Hydroacoustics; 2003, 6; 221-228
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sensitivity of echo envelope fractal dimension to bottom type and bottom depth - numerical results
Autorzy:
Łubniewski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/332051.pdf
Data publikacji:
2003
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
acoustic
seafloor
hydroacoustics
Opis:
The presented results are a part of those obtained within the author's latest work on application of normal incidence methods in acoustic seafloor characterisation. The work included both theoretical and experimental studies on selection of appropriate methods of seafloor echo processing and feature extraction for characterisation of the bottom type, especially, the study of the usefulness of several echo parameters like fractal dimension or statistical moments of the echo envelope. In this paper, the simulation results of the echo envelope fractal dimension dependence on bottom type and bottom depth are presented. They show that to same extent, fractal dimension of an echo may be useful for bottom identification even in a case of varying depth, however, more detailed, theoretical as well as experimental studies are needed.
Źródło:
Hydroacoustics; 2003, 6; 195-198
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł

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