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Wyniki wyszukiwania dla: BEE ACOUSTIC
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Magnetosonic Excitation of the Entropy Perturbations in a Plasma with Thermal Conduction Depending on Temperature
PublikacjaNonlinear excitation of the entropy perturbations by magnetosonic waves in a uniform and infinite plasma model is considered. The wave vector of slow or fast mode forms an arbitrary angle (0 B B ) with the equilibrium straight magnetic field, and all perturbations are functions of the time and longitudinal coordinate. Thermal conduction is the only factor which destroys isentropicity of wave perturbations and causes the nonlinear...
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Numerical Model of Surface and Quasi-Spherical Sea Noise and Its Application to Analysis of DIFAR Systems
PublikacjaVarious types of passive sonar systems are used to detect submarines. These activities are complex and demanding. Therefore, computer simulations are most often used at the design stage of these systems. For this reason, it is also necessary to simulate the acoustic ambient noise of the sea. The article proposes a new numerical model of surface and quasi-spherical sea noise and presents its statistical parameters. The results of...
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Quality Evaluation of Speech Transmission via Two-way BPL-PLC Voice Communication System in an Underground Mine
PublikacjaIn order to design a stable and reliable voice communication system, it is essential to know how many resources are necessary for conveying quality content. These parameters may include objective quality of service (QoS) metrics, such as: available bandwidth, bit error rate (BER), delay, latency as well as subjective quality of experience (QoE) related to user expectations. QoE is expressed as clarity of speech and the ability...
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Modelling and Measurement of Folk Guitar: Truss Rod and Strings in Numerical Analysis of Tone
PublikacjaThe study makes an attempt to model a complete vibrating guitar including its non-linear features, specifically the tension-compression of truss rod and tension of strings. The purpose of such a model is to examine the influence of design parameters on tone. Most experimental studies are flawed by uncertainties introduced by materials and assembly of an instrument. Since numerical modelling of instruments allows for deterministic...
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Magnetoacoustic Heating of Plasma Caused by Periodic MagnetosoundPerturbations with Discontinuities in a Quasi-Isentropic Magnetic Gas
PublikacjaThe magnetoacoustic heating of plasma by harmonic or periodic saw-tooth perturbations at a trans-ducer is theoretically studied. The planar fast and slow magnetosound waves are considered. The wavevector may form an arbitrary angleθwith the equilibrium straight magnetic field. In view of variableθand plasma-β, the description of magnetosound perturbations and appropriate magnetosound heatingis fairly difficult. The scenario of...
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On the Consumption of Multimedia Content Using Mobile Devices: a Year to Year User Case Study
PublikacjaIn the early days, consumption of multimedia content related with audio signals was only possible in a stationary manner. The music player was located at home, with a necessary physical drive. An alternative way for an individual was to attend a live performance at a concert hall or host a private concert at home. To sum up, audio-visual effects were only reserved for a narrow group of recipients. Today, thanks to portable players,...
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Subjective and Objective Comparative Study of DAB+ Broadcast System
PublikacjaBroadcasting services seek to optimize their use of bandwidth in order to maximize user’s quality of experience. They aim to transmit high-quality digital speech and music signals at the lowest bitrate. They intend to offer the best quality under available conditions. Due to bandwidth limitations, audio quality is in conflict with the number of transmitted radio programs. This paper analyzes whether the quality of real-time digital...
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Non-Linear Interaction of Harmonic Waves in a Quasi-Isentropic Flow of Magnetic Gas
PublikacjaThe diversity of wave modes in the magnetic gas gives rise to a wide variety of nonlinear phenomenaassociated with these modes. We focus on the planar fast and slow magnetosound waves in the geometryof a flow where the wave vector forms an arbitrary angleθwith the equilibrium straight magnetic field.Nonlinear distortions of a modulated signal in the magnetic gas are considered and compared to thatin unmagnetised gas. The case of...
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Theoretical studies of nonlinear generation efficiency in a bubble layer
PublikacjaCelem pracy jest teoretyczna analiza propagacji fal o dużym natężeniu w warstwie z pęcherzykami. Przedstawiono model matematyczny zjawiska w tym omówiono problem wyznaczania prędkości fazowej, współczynnika tłumienia i częstotliwości rezonansowej pęcherzyków. Badano zmiany amplitud pierwszej i drugiej harmonicznej ciśnienia fali odbitej i bieżącej w funkcji grubości warstwy oraz względnej koncentracji pęcherzyków. Rozważano pęcherzyki...
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Tinnitus Therapy Based on High-Frequency Linearization Principles - Preliminary Results
PublikacjaThe aim of this work is to present problems related to tinnitus symptoms, its pathogenesis, hypotheses on tinnitus causes, and therapy treatment to reduce or mask the phantom noise. In addition, the hypothesis on the existence of parasitic quantization that accompanies hearing loss has been recalled. Moreover, the paper describes a study carried out by the Authors with the application of high-frequency dither having specially formed...
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Classification of Music Genres Based on Music Separation into Harmonic and Drum Components . Klasyfikacja gatunków muzycznych wykorzystująca separację instrumentów muzycznych
PublikacjaThis article presents a study on music genre classification based on music separation into harmonic and drum components. For this purpose, audio signal separation is executed to extend the overall vector of parameters by new descriptors extracted from harmonic and/or drum music content. The study is performed using the ISMIS database of music files represented by vectors of parameters containing music features. The Support Vector...
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Digital waveguide models of the panpipes
PublikacjaW artykule przedstawiono główne cechy syntezy falowodowej. Omówiono cechy instrumentu fletni Pana. Przedyskutowano cechy zaproponowanych dwóch modeli fletni Pana różniących się złożonością obliczeniową. Pokazano szczegóły implementacyjne tych modeli, a także uzyskane wyniki symulacji dźwięków w modelach. Dokonano porównania dźwięków rzeczywistych i uzyskanych w wyniku syntezy falowodowej.
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Heating caused by a non periodic ultrasound. Theory and calculations on pulse and stationary sources.
PublikacjaPrzedstawiono teorię ewolucji ogrzewania na skutek przejścia fali akustycznej każdego typu. Przedyskutowano obliczenia na podstawie nowych wzorów dla fali impulsowej i uderzeniowej. Wzory zgadzają się z klasycznymi w wypadku fal okresowych.
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Experiments and FE analyses on airborne sound properties of composite structural insulated panels
PublikacjaArtykuł przedstawia wyniki doświadczalne i numeryczne odnośnie właściwości akustycznych paneli budowlanych. Jako panele zastosowano płyty kompozytowe konstrukcyjno-izolacyjne CSIP. Obliczenia numeryczne wykonano MES stosując podejście zaproponowane w pakiecie ABAQUS. Wyniki MES porównano bezpośrednio z doświadczeniami. Zaproponowano różne spsoby poprawy właściwości akustycznych paneli.
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BADANIA ODBIOROWE ŁUKOWEJ KŁADKI DLA PIESZYCH 10T NAD DROGĄ S8 W WARSZAWIE
PublikacjaThe paper presents in situ load testing of the newly build footbridge over S8 expressway in Warsaw. The most characteristic thing for the structure is a shape of arch girders, which correspond with adjacent half-tunnel acoustic baffles. The paper consists of description of the structure, results of the in-situ static and dynamic load testing, results of the numerical simulations, comparative analysis and final conclusions on the...
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Nonlinear Modeling in Time Domain Numerical Analysis of Stringed Instrument Dynamics
PublikacjaMusical instruments are very various in terms of sound quality with their timbre shaped by materials and geometry. Materials' impact is commonly treated as dominant one by musicians, while it is unclear whether it is true or not. The research proposed in the study focuses on determining influence of both these factors on sound quality based on their impact on harmonic composition. Numerical approach has been chosen to allowed independent...
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Wojciech Litwin dr hab. inż.
Osoby1992÷1996 – Studia na Wydziale Mechanicznym Politechniki Gdańskiej1996 – Zatrudniony na Wydziale Oceanotechniki i Okrętownictwa PG2004 – Obrona pracy doktorskiej2014 – obrona rozprawy habilitacyjnej2012 – obejmuje funkcję prodziekan ds. Nauki na Wydziale Oceanotechniki i OkrętownictwaUczestniczył w wielu projektach badawczych oraz pracach zleconych przez przemysł związanych z łożyskowaniem ślizgowym wałów głównych oraz niekonwencjonalnymi...
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Split-Beam Echosounder Data from Puck Bay
PublikacjaThe acoustic data was collected in 2018–2019 in the Bay of Puck in the seasons: autumn, winter, spring. The data was collected during the day and night using three split-beam echosounders with frequencies of 38 kHz, 120 kHz and 333 kHz at a designated study area not far from the city of Hel, while the ship was sailing. To ensure data quality, the echosounders were calibrated and passive noise was measured.
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Robust algorithm for active feedback control of narrowband noise
PublikacjaThe problem of active control of narrowband acoustic noise is considered. It is shown that the proposed earlier feedback control algorithm called SONIC (self-optimizing narrowband interference canceller), based on minimization of the L2-norm performance measure, can be re-derived using the L1 approach. The resulting robust SONIC algorithm is more robust to heavy-tailed measurement noise, such as the αlpha-stable noise, than the...
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EXAMINING INFLUENCE OF VIDEO FRAMERATE AND AUDIO/VIDEO SYNCHRONIZATION ON AUDIO-VISUAL SPEECH RECOGNITION ACCURACY
PublikacjaThe problem of video framerate and audio/video synchronization in audio-visual speech recogni-tion is considered. The visual features are added to the acoustic parameters in order to improve the accuracy of speech recognition in noisy conditions. The Mel-Frequency Cepstral Coefficients are used on the acoustic side whereas Active Appearance Model features are extracted from the image. The feature fusion approach is employed. The...
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Diagnosing wind turbine condition employing a neural network to the analysis of vibroacoustic signals
PublikacjaIt is important from the economic point of view to detect damage early in the wind turbines before failures occur. For this purpose, a monitoring device was built that analyzes both acoustic signals acquired from the built-in non-contact acoustic intensity probe, as well as from the accelerometers, mounted on the internal devices in the nacelle. The signals collected in this way are used for long-term training of the autoencoder...
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EXAMINING INFLUENCE OF VIDEO FRAMERATE AND AUDIO/VIDEO SYNCHRONIZATION ON AUDIO-VISUAL SPEECH RECOGNITION ACCURACY
PublikacjaThe problem of video framerate and audio/video synchronization in audio-visual speech recognition is considered. The visual features are added to the acoustic parameters in order to improve the accuracy of speech recognition in noisy conditions. The Mel-Frequency Cepstral Coefficients are used on the acoustic side whereas Active Appearance Model features are extracted from the image. The feature fusion approach is employed. The...
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Akustyczna analiza natężenia ruchu drogowego dla systemów zarządzania ruchem
PublikacjaW pracy przybliżono wybrane zagadnienia z dziedziny zarządzania transportem drogowym w Polsce i na świecie. W tym kontekście pzredstawiono potrzeby rynkowe, wymagania jak i możliwości w zakresie pozyskiwania informacji o aktualnym stanie sieci drogowych. Zaproponowano akustyczną metodę nadzorowania ruchu drogowego i jej możliwości w kontekście systemów zarządzania ruchem. Przedstawiono schemat akwizycji sygnału wraz z danymi odniesienia....
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New 3D printable filaments with nanodiamonds, physicochemical additives characteristics and electrochemical activity
Dane BadawczeThis dataset contains the physicochemical analyses (XRD, Raman spectroscopy, BET analyses) and electrochemical analyses (CV, EIS) for a new 3D-printable composite has been developed dedicated to electroanalytical applications. Two types of diamondised nanocarbons - detonation nanodiamonds (DNDs) and boron-doped carbon nanowalls (BCNWs) - were added...
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Velocity Field Characteristics at the Inlet to a Pipe Culvert
PublikacjaA poorly designed culvert inlet structure causes scouring, which can lead to the collapse of the culvert and significant damage to the neighboring land. A set of laboratory tests was evaluated to examine velocity distribution at the culvert inlet. A three-dimensional acoustic Doppler velocimeterwas used to measure instantaneous flowvelocity upstream of the culvert. The analysis of mean velocities, turbulence strength, and Reynolds...
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Honey as an indicator of heavy metals in the environment
PublikacjaHoney bees collect nectar, pollen and honeydew to produce bee products. One of them is honey, which due to chemical composition and properties is considered by human as a valuable food product. When honey bees collect substrates to produce honey they can bring contaminants to the hive. The presence of xenobiotics in bee products may lower their quality and devalue their properties, and also endanger human health. Many scientists...
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On the mechanism of photocatalytic reactions on CuxO@TiO2 core–shell photocatalysts
PublikacjaTitania (titanium(IV) oxide) is a highly active, stable, cheap and abundant photocatalyst, and is thus commonly applied in various environmental applications. However, two main shortcomings of titania, i.e., charge carrier recombination and inactivity under visible-light (vis) irradiation, should be overcome for widespread commercialization. Accordingly, titania has been doped, surface modified and coupled with various ions/compounds,...
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Dangerous sound event recognition using Support Vector Machine classifiers
PublikacjaA method of recognizing events connected to danger based on their acoustic representation through Support Vector Machine classification is presented. The method proposed is particularly useful in an automatic surveillance system. The set of 28 parameters used in the classifier consists of dedicated parameters and MPEG-7 features. Methods for parameter calculation are presented, as well as a design of SVM model used for classification....
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An efficient molecular docking using conformational space annealing
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Maciej Tomasz Solarczyk mgr inż.
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Guitar String Sound Retrieved from Moving Pixels
PublikacjaThe aim of this study was to develop a method of visual recording and analyzing the vibrations of guitar strings using high-speed cameras and dedicated video processing algorithms. The recording of a plucked string reveals the way in which the deformations propagate, composing the standing and travelling wave. The paper compares the results for a few selected models of classical and acoustic guitars, and it involves processing...
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Backscattering properties of southern Baltic herring
PublikacjaReliable TS(L) relationship is required to improve acoustic algorithms of abundanceestimation of Baltic herring. The relationships, empirically obtained in different parts of theBaltic Sea, produce up to 8 dB – difference in the herring TS. In order to develop an accurateTS(L) relationship, it is important to analyze factors controlling the TS variability. Thepossible impact of the regional difference...
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The development of an underwater telephone for digital communication purposes
PublikacjaThe underwater telephone HTL-10 has been designed to provide voice and data communication between helicopter and submarines using acoustic waves. It works in a half-duplex mode and uses analogue power-efficient modulation in the form of a single side-band, suppressed carrier, in a wide range of frequencies. It generates the transmitted signal, and processes the received signals. It is implemented with the use of digital signal...
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An Attempt to Create Speech Synthesis Model That Retains Lombard Effect Characteristics
PublikacjaThe speech with the Lombard effect has been extensively studied in the context of speech recognition or speech enhancement. However, few studies have investigated the Lombard effect in the context of speech synthesis. The aim of this paper is to create a mathematical model that allows for retaining the Lombard effect. These models could be used as a basis of a formant speech synthesizer. The proposed models are based on dividing...
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The conception of energetic investigations of the multisymptom fatigue of the simple mechanical systems' constructional materials
PublikacjaThe article presents the basic assumptions of the research project aimed, as the main scientific purpose, an identification of the slow-changeable energy processes surrounding the high-cycle fatigue of constructional materials within the plain mechanical system, especially the marine one, for diagnostic purposes. There is foreseen an application of alternative diagnostic methods based on energetic observations of the multi-symptom,...
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Adam Bolt dr hab. inż.
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Robot Eye Perspective in Perceiving Facial Expressions in Interaction with Children with Autism
PublikacjaThe paper concerns automatic facial expression analysis applied in a study of natural “in the wild” interaction between children with autism and a social robot. The paper reports a study that analyzed the recordings captured via a camera located in the eye of a robot. Children with autism exhibit a diverse level of deficits, including ones in social interaction and emotional expression. The aim of the study was to explore the possibility...
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Description of symmetrical prolate ellipsoid (sphere) magnetic signature parameters-Be = 50 mT, I = 70 deg, z = -10 m, a =4 m, e = 1, mr = 100
Dane BadawczeThe Earth magnetic field (Fig.1): BE – total magnetic flux density, BEx – x component of the Earth magnetic flux density, BEy = 0 y component of the Earth magnetic flux density, BEz – z component of the Earth magnetic flux density, I – inclination of the Earth magnetic field.
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Description of symmetrical prolate ellipsoid (sphere) magnetic signature parameters-Be = 50 mT, I = 70 deg, z = -100 m, a =4 m, e = 1, mr = 100
Dane BadawczeThe Earth magnetic field (Fig.1): BE – total magnetic flux density, BEx – x component of the Earth magnetic flux density, BEy = 0 y component of the Earth magnetic flux density, BEz – z component of the Earth magnetic flux density, I – inclination of the Earth magnetic field.
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Description of symmetrical prolate ellipsoid (sphere) magnetic signature parameters-Be = 50 mT, I = 70 deg, z = -50 m, a =4 m, e = 1, mr = 100
Dane BadawczeThe Earth magnetic field (Fig.1): BE – total magnetic flux density, BEx – x component of the Earth magnetic flux density, BEy = 0 y component of the Earth magnetic flux density, BEz – z component of the Earth magnetic flux density, I – inclination of the Earth magnetic field.
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Description of symmetrical prolate ellipsoid (sphere) magnetic signature parameters-Be = 50 mT, I = 70 deg, z = -10 m, a =4 m, e = 1, mr = 100
Dane BadawczeThe Earth magnetic field (Fig.1): BE – total magnetic flux density, BEx – x component of the Earth magnetic flux density, BEy = 0 y component of the Earth magnetic flux density, BEz – z component of the Earth magnetic flux density, I – inclination of the Earth magnetic field.
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Description of symmetrical prolate ellipsoid (sphere) magnetic signature parameters-Be = 50 mT, I = 70 deg, z = -20 m, a =4 m, e = 1, mr = 100
Dane BadawczeThe Earth magnetic field (Fig.1): BE – total magnetic flux density, BEx – x component of the Earth magnetic flux density, BEy = 0 y component of the Earth magnetic flux density, BEz – z component of the Earth magnetic flux density, I – inclination of the Earth magnetic field.
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Generation of the vorticity Mode by Sound in a Relaxing Maxwell Fluid
PublikacjaPraca dotyczy nowej teorii akustyki nieliniowej badającej związki modu akustycznego z modem wirowym w płynach z relaksacją maxwellowską. Wyprowadzone zostało równanie ewolucyjne dla modu wirowego wywołanego dźwiękiem, które można stosować zarówno do dźwięków okresowych, jak i aperiodycznych. Przedstawiono przykłady generacji modu wirowego w płynie maxwellowskim z relaksacją wywołanego okresową i aperiodyczną falą dźwiękową.
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Multimedia System for Environmental Noise Monitoring. [Multimedialny System Monitorowania Hałasu Środowiskowego]
PublikacjaIntroductionNumerous reports relating to noise threats in Poland indicate that they occur commonly. The noise has an enormous impact on the health and life quality of the human beings. Noise pollution in Poland is greater than in others UE countries, moreover it has been increased recently. Taking into account 2002/49/WE directive related to the control and assessment of environmental noise a necessity of monitoring these threats...
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Combined spline wavelet decomposition for 3d seafloor imaging from multibeam sonar echoes
PublikacjaThe paper proposes combined spline-wavelet approach to the raw echoes seaflor imaging from Multibeam Sonar System (MBSS) records. Wavelet representation is closely related to image representation, due to its unique approximations properties. Splines have the best approximation properties among all known wavelets of a given order, so they are best suited for approximating of smooth seafloor surface. Additionaly, wavelet bases have...
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Broadband Sonar with a Cylindrical Antenna
PublikacjaSkutkiem wzrostu szerokości widma sygnałów w sonarach z płaskimi antenami jest wzrost szerokości odchylanych wiązek, jeżeli beamformer dokonuje kompensacji faz tylko na częstotliwości środkowej widma. W artykule przedstawiono wyniki obliczeń, które odpowiadają na pytanie, czy podobny efekt występuje w szerokopasmowych sonarach z anteną cylindryczną. Obliczenia przeprowadzono dla anten nadawczych o szerokich wiązkach i anten odbiorczych...
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Instantaneous Heating and Cooling Caused by Periodic or Aperiodic Sound of Any Characteristic Duration in a Gas with Vibrational Relaxation
PublikacjaThermodynamic relaxation of internal degrees of a molecule's freedom in a gas occurs with some characteristic time. This makes wave processes in a gas behave differently depending on the ratio of characteristic duration of perturbations and the relaxation time. In particular, generation of the secondary non-wave modes by intense sound in a nonlinear flow dependens on frequency. These kinds of interaction are considered in this...
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Seabed characterisation using spectral moments of the echo signal
PublikacjaZbadano użyteczność zastosowania momentów spektralnych obwiedni echa w rozpoznawaniu i klasyfikacji dna morskiego. Przeprowadzono obliczenia momentów spektralnych dla około 15000 ech od dna zarejestrowanych w rejonie Bałtyku Południowego i potwierdzono tezę, że wartości tych momentów skorelowane są silnie z typem dna i rodzajem osadów.
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Application of splines and wavelets along with TIN decimation to 3D imagingof seafloor from multibeam sonar data
PublikacjaW pracy przedstawiono dwie metody reprezentacji danych batymetrycznych otrzymanych z pomiarów z użyciem sonaru wielowiązkowego. Reprezentacja przy pomocy funkcji sklejanych jest odpowiednia dla baz danych, podczas gdy reprezentacja z wykorzystaniem funkcji falkowych posiada dobre właściwości kompresyjne.
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Indirect Methods of Fish Target Strenght Estimation in Absolute and Logarithmic Domain
PublikacjaW artykule przedstawiono wyniki estymacji zasobów ryb realizowane w dziedzinie absolutnej (jako estymacja rozproszenia wstecznego) oraz w dziedzinie logarytmicznej (estymacja siły celu).