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Wyszukujesz frazę "Moszynski, M." wg kryterium: Autor


Tytuł:
Beam pattern probability density function for multiple echo statistics
Autorzy:
Moszyński, M.
Powiązania:
https://bibliotekanauki.pl/articles/331690.pdf
Data publikacji:
2000
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
When fish target strength is estimated indirectly from single beam echo peak values the inverse techniques of solving the "single-beam integral equation" are recently quite satisfactorily used. This approach needs prior knowledge of beam pattern PDF, as it represents the kernel of the integral equation and is usually estimated under assumption of uniform spatial distribution of fish. However, it may be shown that in some cases this assumption not necessarily must be valid. For instance, when the density of fish is increased one receives multiple echoes from one fish observed in successive transmissions. Moreover, in some situations uniform assumption works properly only for the cases of large number of samples. Taking into account this phenomenon the accuracy of solution may be improved by including fish counting statistics in calculating the beam pattern PDF.
Źródło:
Hydroacoustics; 2000, 3; 149-154
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Specific features of data processing in microcontroller driven miniaturized digital echosounder
Autorzy:
Moszyński, M.
Powiązania:
https://bibliotekanauki.pl/articles/331790.pdf
Data publikacji:
2001
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
Application of the modem VLSI digital technology to the area of portable sonar equipment, like depth sounders, fish finders, short-range sonars etc., provide automatic acquisition and recording of acoustic data, along with communication with various marine equipment, like chart plotter, GPS, or even host computer, using NMEA OJ83 protocol. The paper presents one such application, which constitutes the design of miniaturized microcontroller driven digital echosounder, and in particular (he bathymetric data processing employed in this design. The dedicated software for such a system consists of two parts: one hard-coded in the microcontroller EEPROM memory and the other running on attached equipment. The first one uses unique features of the microcontroller, which allows real-time compression of echo data, implementation of bottom tracking algorithms and communication with host computer, while the latter in general is used for presentation of echo signals and displaying of various echogram graphics along with associate reports.
Źródło:
Hydroacoustics; 2001, 4; 173-176
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On a threshold induced bias in fish target strength estimation
Autorzy:
Moszyński, M.
Powiązania:
https://bibliotekanauki.pl/articles/332238.pdf
Data publikacji:
2003
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
fisheries acoustics
marine organisms
Opis:
In fisheries acoustics the bias introduced by a system threshold in the integration of echoes from fish and other marine organisms has long been recognized. Some simple methods for evaluating such a bias uses Rayleigh assumption applied to fish backscattering length distribution. More adequate methods require that the target strength distribution of the fish and directivity pattern of the transducer be known. The method proposed here uses statistical approach for correction of target strength probability density function (PDF). The theory of conditional target strength PDF and conditional beam pattern PDF is derived. It provides correction not only for mean value of target strength but for whole distribution. The data obtained from simulations are presented and compared with those obtained from single-beam inverse processing.
Źródło:
Hydroacoustics; 2003, 6; 49-52
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On statistical linear inverse problems in fishery acoustics
Autorzy:
Moszyński, M.
Powiązania:
https://bibliotekanauki.pl/articles/332520.pdf
Data publikacji:
2007
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
The paper summarizes several aspects of solving statistical linear inverse problems that occur in the processes related to fish abundance estimation performed on the basis of acoustically acquired data. As the difficulty in solving such problems inherently comes from uncertainty in determination of so called inversion kernel, the paper discusses the key approaches that lead to formulation of statistical relations between acoustic echoes observed from swimming fish in their natural environment and mostly required fish parameter, namely physical length of the fish.
Źródło:
Hydroacoustics; 2007, 10; 131-142
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Indirect fish target strength estimation using adaptive kernel
Autorzy:
Moszyński, M.
Powiązania:
https://bibliotekanauki.pl/articles/332772.pdf
Data publikacji:
2001
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
The typical approach to the problem of indirect fish target strength estimation from data collected using single-beam system is based on inversion of probability density function (PDF) of measured fish echo level. Due to ill-conditioning of most inversion algorithms, small errors in input data, and inaccuracies in the assumed form of the kernel, may result in large errors at the output. Therefore, al! modern inversion algorithms use sophisticated techniques to achieve satisfying results, assuming fixed kernel in the inversion procedure. The paper presents different approach, which uses adaptive construction of the kernel, under assumption of non-negative constraints in the obtained estimate of fish target strength PDF. As a result, the more reliable beam pattern PDF is obtained which leads to unbiased and more accurate estimate offish target strength PDF, than in the conventional (fixed kernel) methods.
Źródło:
Hydroacoustics; 2001, 4; 177-180
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nuclear techniques in homeland security
Autorzy:
Moszyński, M.
Powiązania:
https://bibliotekanauki.pl/articles/147942.pdf
Data publikacji:
2005
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
border monitoring
nuclear techniques in border monitoring
Opis:
Selected methods for border monitoring, utilizing nuclear techniques are discussed, with a particular emphasis on those developed with the contribution of our Institute. It covers a basic inspection of the borders against smuggling of radioactive materials, as well as known systems using linear accelerators of electrons for inspection of large trucks by X-ray radiography. More advanced active methods based on tagged neutron inspection systems to monitor explosives and methods based on photofission to detect fissile materials are presented, too.
Źródło:
Nukleonika; 2005, 50,suppl.3; 53-58
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The beam pattern PDF in target strength estimation - theoretical and practical approach
Autorzy:
Moszyński, M.
Stepnowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/331912.pdf
Data publikacji:
1997
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
The knowledge of beam pattem probability density function (PDF) plays a crucial role in target strength estimation when using indirect methods. The paper describes the theoretical and practical aspects of approximations applied in calculating the PDF of this deterministic function from a probabilistic point of view. The solution of differential equation presented in the paper leads to a unified approach to approximations and has a elear interpretation.
Źródło:
Hydroacoustics; 1997, 1; 31-26
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Using concentrated spectrogram for analysis of audio acoustic signals
Autorzy:
Czarnecki, K.
Moszyński, M.
Powiązania:
https://bibliotekanauki.pl/articles/332421.pdf
Data publikacji:
2012
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
The paper presents results of time-frequency analysis of audio acoustic signals using the method of Concentrated Spectrograph also known as "Cross-spectral method" or "Reassignment method". Presented algorithm involves signal's local group delay and channelized instantaneous frequency to relevantly redistribute all Short-time Fourier transform lines in time-frequency plain. The main intention of the paper is to compare various guitar playing techniques including legato, staccato, vibrato, glissando, slide and bending. Additionally, the advantages of concentrated spectrograms especially high energy concentration in comparison with classical spectrogram based directly only on Short-time Fourier transform are presented. Moreover, the vibrato playing technique is considered also for another musical instruments: flute and violin.
Źródło:
Hydroacoustics; 2012, 15; 27-32
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The estimation of norwegian cod size distribution from acoustic data
Autorzy:
Moszyński, M.
Stepnowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/332441.pdf
Data publikacji:
2006
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
The paper presents an algorithm for estimation the fish length distribution from acoustic target strength data. The theory of scattering from a tilted cylinder is used for modelling the fish directivity pattern of swimbladdered fish. The model allows for formulating the dependence of target strength on two main components; the maximum target strength and the fish directivity pattern. As both terms depend on fish length, the inverse technique used when processing is performed on introduced conditional distributions. The effect of fish tilt angle is in this way removed, or deconvolved from the target strength distribution.. The resulting fish maximum target strength distribution is further converted into fish length distribution using equivalent parameters for swimbladder morphology. The method is verified on actual data acquired during the Lofoten 2004 survey on spawning grounds of North East Arctic cod (Gadus morhua).
Źródło:
Hydroacoustics; 2006, 9; 133-138
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kalman filtering for 3d real time data visualization of multibeam sonar records
Autorzy:
Demkowicz, J.
Moszyński, M.
Powiązania:
https://bibliotekanauki.pl/articles/331515.pdf
Data publikacji:
2003
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
Kalman filtering
sonar records
visualization
Opis:
For the last decade multibeam sonars have been increasingly used for mapping and visualization of the bottom surfaces to provide the 'physical bases' for environmental studies due to theirs unprecedentedly high resolution mapping ability. However, the raw sonar records are subject to systematic errors, random noise and outliers. In this paper Kalman filtering approach to generating optimal estimates of bottom surface from a noisy raw sonar records is presented. The experiment on the surface indicates that after applying the Kalman filtering technique the outliers of raw records can be efficiently detected and removed. Moreover in the same time, the two-step Kalman filtering method is applied, which aims to filter every multibeam sonar swath and enable 3D seabed visualization in real time. The 3D bottom relief before, and after the filtering method application is also presented.
Źródło:
Hydroacoustics; 2003, 6; 189-194
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling the seafloor 3D relief and its reconstruction from multibeam sonar data
Autorzy:
Łubniewski, Z.
Moszyński, M.
Powiązania:
https://bibliotekanauki.pl/articles/331622.pdf
Data publikacji:
2001
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
The simple, real-time procedure for seafloor relief reconstruction and simultaneous seabed type identification using echo data from hypothetical multibeam sonar system was proposed. The algorithm was tested using artificially generated relief and seabed type data. In the first stage, 3D surface of seafloor was generated, using the inverse Fourier transformation of the 2D spatial frequency spectrum of power law form. In the second stage, the generation. of the set of multibeam sonar data, which simulated echoes collected from seabed, was performed with account for the distances from transducer to particular surface elements, scattering coefficient and the angles of insonification. Finally, the spatial form of seabed was reconstructed using the simulated data, while bottom type was identified simultaneously using estimated angular dependence of backscattering coefficient. The obtained results showed the good performance of the proposed reconstruction procedure for artificial data and suggested verification of the algorithm using real data.
Źródło:
Hydroacoustics; 2001, 4; 153-156
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A spice equivalent circuit for modeling the performance of dual frequency echo-sounder
Autorzy:
Moszynski, M.
Lis, W.
Powiązania:
https://bibliotekanauki.pl/articles/331762.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
The paper presents novel network equivalent circuit of piezoceramic circular disc transducer that takes into account thickness and radial mode of vibrations. The starting point of the analysis is 4-port description of circular disc element representing the solution of wave equation set in radial and thickness directions. The approximate solution for harmonic case is represented in the form of 4x4 matrix, which is synthesized and implemented in circuit analysis software. The network is extended with acoustical port that allows for pressure calculations in the similar manner as when measuring echo-sounder transmitting and receiving parameters. The model is especially useful for simulating complete electronic circuit of dual frequency echo-sounders based on single circular disc transducer.
Źródło:
Hydroacoustics; 2011, 14; 165-170
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The use of numerical methods for the analysis of phase phenomena in multi-element antennas
Autorzy:
Lis, W.
Moszyński, M.
Powiązania:
https://bibliotekanauki.pl/articles/331910.pdf
Data publikacji:
2003
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
numerical methods
antenna signals
acoustics
Opis:
The article describes an analysis of the effects of mutual impedance on the phase of multi-element antenna signals. The calculations were made using a substitute model of a Mason ultrasonic transducer. The effects of self and mutual impedance on the phase of multielement antenna signals were considered.
Źródło:
Hydroacoustics; 2003, 6; 215-220
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The statistics of fish echo traces - models and validation
Autorzy:
Moszynski, M.
Stepnowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/332758.pdf
Data publikacji:
2000
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
Beam pattern probability density function (PDF) plays important role in indirect fish target strength estimation methods as it constitutes the kernel of any form of a "single-beam integral equation" that should be solved for unknown target strength PDP. Typically, the beam pattern PDF is calculated under the assumption of uniform spatial distribution of fish targets in beam pattern cross-section. However, in some cases this assumption can not be justified due to fish or vessel movement, and different number of fish echoes in fish traces. In the paper, two different models of fish traces statistics were investigated: one assuming the vessel movement with stationary fish and the other with stationary vessel and moving fish. Both approaches were modelled numerically and later verified experimentally using data obtained from a dual-beam system.
Źródło:
Hydroacoustics; 2000, 3; 155-160
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
3D reconstruction of seafloor from side-scan records
Autorzy:
Bikonis, K.
Moszyński, M.
Powiązania:
https://bibliotekanauki.pl/articles/332770.pdf
Data publikacji:
2005
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
The modern underwater acoustic equipment, like multibeam sonar, is able to provide the data which allows for unambiguous localization and also 3D visualisation of targets of different kinds, including wrecks, mines and other submerged objects. The large amount of information that seems to be useful for this purpose, could also be extracted from side-scan sonar data, which has been collected over years within different survey regions. In this context, the paper concerns the development of side-scan data processing method for 3D reconstruction of seafloor and its imaging. In this paper, two novel approaches are proposed. The first utilises the more accurate models of backscattering, including the differences in signatures of several types of objects. The second is based on definition and investigation of some quantitative descriptors of geometric features expected to be found in images of localised objects of artificial origin. The preliminary results obtained by application of these techniques to side-scan sonar data processing will be discussed in this paper.
Źródło:
Hydroacoustics; 2005, 8; 9-14
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł

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