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Wyniki wyszukiwania dla: SOUND INTENSITY MEASUREMENTS
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Measurements and Visualization of Sound Intensity Around the Human Head in Free Field Using Acoustic Vector Sensor
PublikacjaThis paper presents measurements and visualization of sound intensity around the human head simulator in a free field. A Cartesian robot, applied for precise positioning of the acoustic vector sensor, was used to measure sound intensity. Measurements were performed in a free field using a head and torso simulator and the setup consisting of four different loudspeaker configurations. The acoustic vector sensor was positioned around...
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Sound intensity distribution around organ pipe
PublikacjaThe aim of the paper was to compare acoustic field around the open and stopped organ pipes. The wooden organ pipe was located in the anechoic chamber and activated with a constant air flow, produced by an external air-compressor. Thus, long-term steady state response was possible to obtain. Multichannel acoustic vector sensor was used to measure the sound intensity distribution of radiated acoustic energy. Measurements have been...
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Acoustic Detector of Road Vehicles Based on Sound Intensity
PublikacjaA method of detecting and counting road vehicles using an acoustic sensor placed by the road is presented. The sensor measures sound intensity in two directions: parallel and perpendicular to the road. The sound intensity analysis performs acoustic event detection. A normalized position of the sound source is tracked and used to determine if the detected event is related to a moving vehicle and to establish the direction of movement....
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Hardness measurements for assessment of cavitation intensity
PublikacjaArtykuł opisuje możliwość zastosowania pomiarów teardości erodowanego materiału do oceny natężenia zjawiska kawitacji. Proponowana metoda zakłada, że cała energia implodujących pęcherzyków kawitacyjnych zamieniana jest na przyrost twardości warstwy wierzchniej materiału
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Numerical modeling of sound intensity distributions around acoustic transducer
PublikacjaThe aim of this research study is to measure, simulate and compare sound intensity distribution generated by the acoustic transducers of the loudspeaker. The comparison of the gathered data allows for validating the numerical model of the acoustic radiation. An accurate model of a sound source is necessary in mathematical modeling of the sound field distribution near the scattering obstacles. An example of such obstacle is a human...
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Estimation of Average Speed of Road Vehicles by Sound Intensity Analysis
PublikacjaConstant monitoring of road traffic is important part of modern smart city systems. The proposed method estimates average speed of road vehicles in the observation period, using a passive acoustic vector sensor. Speed estimation based on sound intensity analysis is a novel approach to the described problem. Sound intensity in two orthogonal axes is measured with a sensor placed alongside the road. Position of the apparent sound...
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3D Acoustic Field Intensity Probe Design and Measurements
PublikacjaThe aim of this paper is two-fold. First, some basic notions on acoustic field intensity and its measurement are shortly recalled. Then, the equipment and the measurement procedure used in the sound intensity in the performed research study are described. The second goal is to present details of the design of the engineered 3D intensity probe, as well as the algorithms developed and applied for that purpose. Results of the intensity...
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Measurement and visualization of sound intensity vector distribution in proximity of acoustic diffusers
PublikacjaIn this work, we would like to present analyses and visualizations of sound intensity distribution measured in proximity of an acoustic diffuser. Such distribution may be used for estimation of basic acoustic parameters of a diffuser. Measurement is performed with the use of a logarithmic sine sweep which allows for the analysis of waves scattered by the diffuser and rejecting the direct sound signal component. Pressure and sound...
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Development of the sound field 3D intensity probe based on miniature microphones
PublikacjaThe engineered measuring probe uses three pairs of miniature microphones coupled. The signals from the microphones after an initial amplification are fed to differential circuits. Due to the required symmetry of the circuit it was necessary to select electronic components very carefully. Moreover, additional digital signal processing techniques were applied to avoid amplitude and phase mismatch. The view of the engineered probe...
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RADIATION OF HIGH INTENSITY SOUND BY CIRCULAR DISC BY MEANS OF THE NUMERICAL METHOD
PublikacjaThe main goal of this paper is to find sound pressure distribution radiated by the circular piezoelectric disc that vibrates with the finite amplitude. There has been presented the pressure distribution close to the radiating surface. Also it is shown the sound pressure distribution in the 3D form. The mathematic modeling was carried out on the base of the nonlinear acoustic equation with the proper boundary condition. The axial...
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3D Sound Intensity Measurement Around Organ Pipes Using Acoustic Vector Sensors
PublikacjaThe aim of the presented paper was to obtain and visualize sound intensity distribution of radiated acoustic energy around the organ pipes. The experimental setup consisted of the multichannel acoustic vector sensor and the specialized Cartesian robot. Measurements were performed in free field with spatial resolution of 0.1 [m]. Two organ pipes, i.e. wooden and metal were measured during the ex-periment. The organ pipes were activated...
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Measurements and visualization of sound field distribution around organ pipe
PublikacjaMeasurements and visualization of acoustic field around an organ pipe are presented. Sound intensity technique was applied for this purpose. Measurements were performed in free field. The organ pipe was activated with a constant air flow, produced by an external compressor, aimed at obtaining long-term steady state responses of generated acoustic signal. Sound energy distribution was measured in a defined fixed grid of points...
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Sound Field Intensity Measurements and Visualization around the Human Head Model . Rozkłąd natężenia pola akustycznego w komorze bezechowej obecności sztucznej głowy i w przypadku braku jej obecności
PublikacjaThe main goal of this research study was to measure and visualize sound field intensity distribution in and without presence of the human head model. Measurements were performed in the anechoic chamber with the 5 cm grid. Experimental setup consisted of a multitone generator, two loudspeakers, human head model, intensimetric probe, the Cartesian robot applied for precise positioning of the acoustic sensor, and an analyzer. Based...
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Principles of computing and displaying the results of detection by underwater systems as part of sound velocity measurements.
PublikacjaPraca zawiera szczegółowy opis metodyki prowadzenia obliczeń i ekspozycji wyników przewidywanych warunków detekcji systemów hydroakustycznych w zestawie pomiarowym rozkładów prędkości dźwięku. Podstawa obliczeń są zamierzone rozkłady wartości prędkości propagacji dźwięku w funkcji głębokości akwenu a metodyka polega na kojarzeniu wyliczonego metodą gęstości promieni rozkładu natężenia fali akustycznej w pionowym przekroju akwenu...
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On the possibility of the application of magnetoacoustic emission intensity measurements for the diagnosis of thick-walled objects in the industrial environment
PublikacjaArtykuł przedstawia wyniki pomiarów sygnału emisji magnetoakustycznej (EMA) wykonanych na obiektach grubościennych w środowisku przemysłowym oraz omawia możliwe sposoby jego dalszej analizy. Pomimo tego, ze bezpośredni pomiar sygnału EMA nie pozwala na określenie jego natężenia w artykule wykazano, że możliwa jest separacja użytecznego sygnału od szumów tła albo poprzez analogowe filtrowanie sprzętowe albo poprzez cyfrową analizę...
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Interactions of N-alkyl-N-methylmorpholinium based ionic liquids with acetonitrile studied by density and velocity of sound measurements and molecular dynamics simulations
PublikacjaMorpholinium-based ionic liquids (ILs) and their mixtures with polar co-solvents are an interesting class of emerging electrolytes in electrochemistry that is relatively poorly studied. In this work, densities and sound velocities of four ILs, N-ethyl-N-methylmorpholinium tetrafluoroborate, N-butyl-N-methylmorpholinium tetrafluoroborate, N-octyl-N-methylmorpho-linium tetrafluoroborate and N-decyl-N-methylmorpholinium tetrafluoroborate...
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HYDROACOUSTIC NOISE MEASUREMENTS
PublikacjaThe paper deals mainly with investigation of underwater noise that propagation is in shallow water. In this paper has been presented the experimental investigation results concerning the distribution of the sound field pressure generated by moving ships in the shallow water at the small distance from the ship. The main acoustical characteristics describing features of the field are spectrograms in pseudo 3D system – distance and frequency...
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Multiple sound sources localization in real time using acoustic vector sensor
PublikacjaMethod and preliminary results of multiple sound sources localization in real time using the acoustic vector sensor were presented in this study. Direction of arrival (DOA) for considered source was determined based on sound intensity method supported by Fourier analysis. Obtained spectrum components for considered signal allowed to determine the DOA value for the particular frequency independently. The accuracy of the developed...
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Multiple sound sources localization in free field using acoustic vector sensor
PublikacjaMethod and preliminary results of multiple sound sources localization in free field using the acoustic vector sensor were presented in this study. Direction of arrival (DOA) for considered source was determined based on sound intensity method supported by Fourier analysis. Obtained spectrum components for considered signal allowed to determine the DOA value for the particular frequency independently. The accuracy of the developed...
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Broadening the scope of measurement and analysis of vibrations of an organ pipe employing intensity probe, simulations, and highspeed camera
PublikacjaThis paper shows an integrated approach to measure, analyze, and model phenomena occurring in an organ pipe driven by pressurized air. The aim of this paper is two-fold, i.e., to measure the pressure signal and the intensity field around the mouth by means of an intensity probe and to visualize and observe the motion of the air jet, which represents the excitation mechanism of the system. This is realized through two techniques,...
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Counting and tracking vehicles using acoustic vector sensors
PublikacjaA method is presented for counting vehicles and for determining their movement direction by means of acoustic vector sensor application. The assumptions of the method employing spatial distribution of sound intensity determined with the help of an integrated 3D intensity probe are discussed. The intensity probe developed by the authors was used for the experiments. The mode of operation of the algorithm is presented in conjunction...
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An in-depth look at the tire rubber hardness influence on tire/road noise measurements
PublikacjaWhen assessing the acoustic quality of a road pavement with the close-proximity (CPX) or the on-board sound intensity (OBSI) method, the rubber hardness of the reference tire substantially affects the measurement. Practical experience shows that measurement tires can get significantly harder within a single measurement season. This is why one would like to normalize measurements to a reference rubber hardness. The recently published...
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PHONEME DISTORTION IN PUBLIC ADDRESS SYSTEMS
PublikacjaThe quality of voice messages in speech reinforcement and public address systems is often poor. The sound engineering projects of such systems take care of sound intensity and possible reverberation phenomena in public space without, however, considering the influence of acoustic interference related to the number and distribution of loudspeakers. This paper presents the results of measurements and numerical simulations of the...
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Rough Set Based Modeling and Visualization of the Acoustic Field Around the Human Head
PublikacjaThe presented research aims at modeling acoustical wave propagation phenomena by applying rough set theory in a novel manner. In a typical listening environment sound intensity is determined by numerous factors: a distance from a sound source, signal levels and frequencies, obstacles’ locations and sizes. Contrarily, a free-field is characterized by direct, unimpeded propagation of the acoustical waves. The proposed approach is...
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The shallow sea experiment with usage of linear hydrophone array
PublikacjaPurpose of this article is to present designed and made linear hydrophone array and the results obtained during in situ trails on Gulf of Gdańsk. The measuring system allowed to localize hydrophones in the selected points and perform measurements in both the horizontal antenna positioning and vertical. Made in this way recordings allow creating accurate 3D imaging of sound intensity/propagation. During research three floating objects...
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Detection of the Incoming Sound Direction Employing MEMS Microphones and the DSP
PublikacjaA 3D acoustic vector sensor based on MEMS microphones and its application to road traffic monitoring is presented in the paper. The sensor is constructed from three pairs of digital MEMS microphones, mounted on the orthogonal axes. Signals obtained from the microphones are used to compute sound intensity vectors in each direction. With this data, it is possible to compute the horizontal and vertical angle of an incoming sound....
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Estimating Traffic Intensity Employing Passive Acoustic Radar and Enhanced Microwave Doppler Radar Sensor
PublikacjaInnovative road signs that can autonomously display the speed limit in cases where the trac situation requires it are under development. The autonomous road sign contains many types of sensors, of which the subject of interest in this article is the Doppler sensor that we have improved and the constructed and calibrated acoustic probe. An algorithm for performing vehicle detection and tracking, as well as vehicle speed measurement,...
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Eulerian motion magnification applied to structural health monitoring of wind turbines
PublikacjaSeveral types of defects may occur in wind turbines, as physical damage of blades or gearbox malfunction. A wind farm monitoring and damage prediction system is built to observe abnormal vibrations of elements of wind turbine: blades, nacelle, and tower. Contactless methods are developed which do not require turbine stopping. In this work, structural health monitoring of a wind turbine is evaluated using a conversion from the captured...
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Automatic sound source localization in disturbing conditions using acoustic vector sensors
PublikacjaA concept, practical realization and applications of a passive acoustic radar to automatic localization and tracking of sound sources in disturbing conditions were presented in the paper. The device consists of the new kind of multichannel miniature sound intensity sensors and a group of digital signal processing algorithms. The sensitivity of the realized acoustic radar was examined in free sound field. Several kinds of sound...
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Application of passive acoustic radar to automatic localization, tracking and classification of sound sources
PublikacjaA concept, practical realization and applications of the passive acoustic radar to automatic localization, tracking and classification of sound sources were presented in the paper. The device consists of a new kind of multichannel miniature sound intensity sensors and a group of digital signal processing algorithms. Contrary to active radars, it does not emit the scanning beam but after receiving surrounding sounds it provides...
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Automatic localization and continous tracking of mobile sound source using passive acoustic radar
PublikacjaA concept, practical realization and applications of the passive acoustic radar for localization and continuous tracking of fixed and mobile sound sources such as: cars, trucks, aircrafts and sources of shooting, explosions were presented in the paper. The device consists of the new kind of multi-channel miniature three dimensional sound intensity sensors invented by the Microflown company and a group of digital signal processing...
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Detection of Water on Road Surface with Acoustic Vector Sensor
PublikacjaThis paper presents a new approach to detecting the presence of water on a road surface, employing an acoustic vector sensor. The proposed method is based on sound intensity analysis in the frequency domain. Acoustic events, representing road vehicles, are detected in the sound intensity signals. The direction of the incoming sound is calculated for the individual spectral components of the intensity signal, and the components...
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Excitation of Non-Wave Modes by Sound of Arbitrary Frequency in a Chemically Reacting Gas
PublikacjaThe nonlinear phenomena in the field of high intensity sound propagating in a gas with a chemical reaction, are considered. A chemical reaction of A → B type is followed by dispersion and attenuation of sound which may be atypical during irreversible thermodynamic processes under some conditions. The first and second order derivatives of heat produced in the chemical reaction evaluated at the equilibrium temperature, density and...
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Evaluation of sound event detection, classification and localization in the presence of background noise for acoustic surveillance of hazardous situations
PublikacjaAn evaluation of the sound event detection, classification and localization of hazardous acoustic events in the presence of background noise of different types and changing intensities is presented. The methods for separating foreground events from the acoustic background are introduced. The classifier, based on a Support Vector Machine algorithm, is described. The set of features and samples used for the training of the classifier...
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Selective monitoring of noise emitted by vehicles involved in road traffic
PublikacjaAn acoustic intensity probe was developed measures the sound intensity in three orthogonal directions, making possible to calculate the azimuth and elevation angles, describing the sound source position. The acoustic sensor is made in the form of a cube with a side of 10 mm, on the inner surfaces of which the digital MEMS microphones are mounted. The algorithm works in two stages. The first stage is based on the analysis of sound...
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Determination of the Vehicles Speed Using Acoustic Vector Sensor
PublikacjaThe method for determining the speed of vehicles using acoustic vector sensor and sound intensity measurement technique was presented in the paper. First, the theoretical basis of the proposed method was explained. Next, the details of the developed algorithm of sound intensity processing both in time domain and in frequency domain were described. Optimization process of the method was also presented. Finally, the proposed measurement...
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Hysteresis curves for some periodic and aperiodic perturbations in gases
PublikacjaEvolution of sound in a medium whose properties irreversibly vary in the course of wave propagation, is studied. For example, a gas that is a particular case of a Newtonian fluid is considered. Hysteresis curves, pictorial representations of irreversible attenuation of the sound energy, in the plane of thermodynamic states are plotted. The irreversible losses in internal energy are proportional to the total attenuation and depend...
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Automatic audio-visual threat detection
PublikacjaThe concept, practical realization and application of a system for detection and classification of hazardous situations based on multimodal sound and vision analysis are presented. The device consists of new kind multichannel miniature sound intensity sensors, digital Pan Tilt Zoom and fixed cameras and a bundle of signal processing algorithms. The simultaneous analysis of multimodal signals can significantly improve the accuracy...
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Hysteresis curves and loops for harmonic and impulse perturbations in some non-equilibrium gases
PublikacjaEvolution of sound in a relaxing gas whose properties vary in the course of wave propagation, is studied. A relaxing medium may reveal normal acoustic properties or be acoustically active. In the first case, losses in acoustic energy lead to an increase in internal energy of a gas similarly as it happens in Newtonian fluids. In the second case, acoustic energy increases in the course of sound propagation, and the internal energy...
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Shipping Low Frequency Noise and Its Propagation in Shallow Water
PublikacjaOne of the most significant factor influencing acoustical climate of the sea is underwater noise generated by moving ships. If the considered sea area has features of the shallow water, namely the wave frequency fulfils relation f < 10c/h, where c denotes phase speed of sound, and h is depths of the sea, then in certain distance from the wave source specific image of sound pressure distribution in the mean of wave modes appears....
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Acoustic radar employing particle velocity sensors
PublikacjaA concept, practical realization and applications of a passive acoustic radar to automatic localization, tracking of sound sources were presented in the paper. The device consist of the new kind of multichannel miniature sound intensity sensors and a group of digital signal processing algorithms. Contrary to active radars, it does not emit the scanning beam but after receiving surroundings sounds it provide information about the...
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The Proposition of an Automated Honing Cell with Advanced Monitoring
PublikacjaHoning of holes allows for small shape deviation and a low value of a roughness profile parameter, e.g., Ra parameter. The honing process heats the workpiece and raises its temperature. The increase in temperature causes thermal deformations of the honed holes. The article proposes the construction of a honing cell, containing in addition to CNC honing machine: thermographic camera, sound intensity meter, and software for collecting...
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Akustyka sali koncertowej Szkoły Muzycznej w Gdyni - projekt i realizacja
PublikacjaOmówiono zakres współpracy architekta, akustyka i projektanta wnętrza na przykładzie sali koncertowej Szkoły Muzycznej w Gdyni. Wskazano różnice między projektem akustycznym sali i projektem wnętrza. Podano zasady akustycznego projektowanie sali widowiskowej oraz znaczenie rozproszenia dźwięku dla jakości akustycznej sali. Przedstawiono zasady indywidualnego konstruowania ustrojów rozpraszających dźwięk oraz dostępne na rynku ustroje...
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Detection, classification and localization of acoustic events in the presence of background noise for acoustic surveillance of hazardous situations
PublikacjaEvaluation of sound event detection, classification and localization of hazardous acoustic events in the presence of background noise of different types and changing intensities is presented. The methods for discerning between the events being in focus and the acoustic background are introduced. The classifier, based on a Support Vector Machine algorithm, is described. The set of features and samples used for the training of the...
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Noise emitted by SKM Trains in Gdansk
PublikacjaHigh intensity traffic of SKM trains in Gdansk carries a significant level of noise emission. SKM line runs through the central part of the city and therefore in the vicinity of residential areas and recreational facilities. This research was planned and performed to find out what was the real noise emission of SKM trains and to determine whether the measurement noise values are within allowed limits. Individual acoustic events...
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Images of the Seabed of the Gulf of Gdansk Obtained by Means of the Parametric Sonar
PublikacjaThe main goal of this paper is to present results of the experimental investigation of the seabed by means of parametric echosounder in the form of chosen images. The phenomena of nonlinear interaction between two parallel beams of high intensity gives as a results very narrow beam of low frequency wave, that enables to penetrate the sea bottom. The first step of our investigations was calibration of all the elements of the measuring...
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Pomiar naprężeń własnych metodą Barkhausena za pomocą sondy z wirującym polem magnetycznym
PublikacjaW pracy przedstawiono nowy sposób pomiaru naprężeń własnych w elementach konstrukcji z wykorzystaniem polowego efektu Barkhausena. Informację o stanie naprężeń uzyskano z analizy rozkładu kątowego natężenia efektu Barkhausena zmierzonego w sposób automatyczny poprzez sondę z wirującym polem magnetycznym. Przedstawiono zasadę działania i opis układu pomiarowego oraz przykłady wykorzystania tej metody w ocenie stanu naprężenia w...
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Underwater Acoustic Imaging of the Sea
PublikacjaAcoustic waves are a carrier of information mainly in environments where the use of other types of waves, for example electromagnetic waves, is limited. The term acoustical imaging is widely used in the ultrasonic engineering to imaging areas in which the acoustic waves propagate. In particular, ultrasound is widely used in the visualization of human organs - ultrasonography (Nowicki, 2010). Expanding the concept, acoustical imaging...
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Improving the quality of speech in the conditions of noise and interference
PublikacjaThe aim of the work is to present a method of intelligent modification of the speech signal with speech features expressed in noise, based on the Lombard effect. The recordings utilized sets of words and sentences as well as disturbing signals, i.e., pink noise and the so-called babble speech. Noise signal, calibrated to various levels at the speaker's ears, was played over two loudspeakers located 2 m away from the speaker. In...
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WYKORZYSTANIE TESTU MUSHRA W BADANIU KORZYŚCI UŻYTKOWANIA PROTEZ SŁUCHOWYCH
PublikacjaOcena jakości dopasowania aparatów słuchowych w kontekście korzyści, jakie może przy-nieść proteza jest złożonym zagadnieniem. Obiektywne parametry aparatów, które można wy-znaczyć (np. wzmocnienie czy pasmo przenoszenia) nie zawsze mają bezpośredni i decydujący wpływ w subiektywnej ocenie jakości dopasowania protezy słuchowej przez pacjenta. Pomiary efektywności aparatu słuchowego mogą dotyczyć wielu aspektów, między innymi kompensacji...
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Calibration of acoustic vector sensor based on MEMS microphones for DOA estimation
PublikacjaA procedure of calibration of a custom 3D acoustic vector sensor (AVS) for the purpose of direction of arrival (DoA) estimation, is presented and validated in the paper. AVS devices working on a p-p principle may be constructed from standard pressure sensors and a signal processing system. However, in order to ensure accurate DoA estimation, each sensor needs to be calibrated. The proposed algorithm divides the calibration process...
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Vertical vibration reduction and audible sound analysis in surface grinding with electroplated tools
PublikacjaOne of the first approaches to the development of a grinding process monitoring system based on audible sound sensors is presented in the paper. Electroplated diamond tools (abrasive D64 and D107) were used in a modified single-disc lapping machine configuration for flat grinding of ceramics (Al2O3). The main aim of the machine modification was to reduce the vertical vibration in order to decrease the tool wear and to increase...
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Akustyczna analiza parametrów ruchu drogowego z wykorzystaniem informacji o hałasie oraz uczenia maszynowego
PublikacjaCelem rozprawy było opracowanie akustycznej metody analizy parametrów ruchu drogowego. Zasada działania akustycznej analizy ruchu drogowego zapewnia pasywną metodę monitorowania natężenia ruchu. W pracy przedstawiono wybrane metody uczenia maszynowego w kontekście analizy dźwięku (ang.Machine Hearing). Przedstawiono metodologię klasyfikacji zdarzeń w ruchu drogowym z wykorzystaniem uczenia maszynowego. Przybliżono podstawowe...
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The nonlinear effects of sound in a liquid with relaxation losses
PublikacjaThe nonlinear effects of sound in electrolyte with a chemical reaction are examined. The dynamic equations that govern non-wave modes in the field of intense sound are derived, and acoustic forces of vortex, entropy, and relaxation modes are determined in the cases of low-frequency sound and high-frequency sound. The difference in the nonlinear effects of sound in electrolyte and in a gas with excited vibrational degrees of molecules,...
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Improving automatic surveillance by sound analysis
PublikacjaAn automatic surveillance system, based on event detection in the video image can be improved by implementing algorithms for audio analysis. Dangerous or illegal actions are often connected with distinctive sound events like screams or sudden bursts of energy. A method for detection and classification of alarming sound events is presented. Detection is based on the observation of sudden changes in sound level in distinctive sub-bands...
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generation of the vorticity mode by sound in a bingham plastic
PublikacjaThis study investigates interaction between acoustic and non-acoustic modes, such as vorticity mode,in some class of a non-newtonian fluid called Bingham plastic. The instantaneous equations describinginteraction between different modes are derived. The attention is paid to the nonlinear effects in the fieldof intense sound. The resulting equations which describe dynamics of both sound and the vorticity modeapply to both periodic...
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Application of two-dimensional intensity maps in high-accuracy polarimetry
PublikacjaWe propose the analysis of 2D intensity contour maps which is based on the optical transmission function for the polarizer-specimen-analyzer system. A small modification of the high-accuracy universal polarimeter (HAUP) technique was used to measure the intensity maps (HAUP maps) and determine the phase retardation, linear dichroism (LD) parameters, and multiple light reflection contribution in uniaxial crystals. We have performed...
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Adaptive Personal Tuning of Sound in Mobile Computers
PublikacjaAn integrated methodology for enhancing audio quality in mobile computers is presented. The key features are adaptation of the characteristics of their acoustic track to changing acoustic conditions of the environment and to users’ individual preferences. Signal processing algorithms are introduced that concern: linearization of frequency response, dialogue intelligibility enhancement, and dynamics processing tuned up to the users’...
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Sound engineering as our commitment to its creators in Poland
PublikacjaSound engineering is an interdisciplinary and rapidly expanding domain. It covers many aspects, such as sound perception, studio and sound mastering technology, music information retrieval including content-based search systems and automatic music transcription frameworks, sound synthesis, sound restoration, electroacoustics, and other ones constituting multimedia technology. Moreover, machine learning methods applied to the topics...
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Measurements and Simulations of Engineered Ultrasound Loudspeakers
PublikacjaSimulation and measurement results of the sound emitted from an ultrasound custom-made system with high spatial directivity are presented. The proposed system is using modulated ultrasound waves which demodulate in nonlinear medium resulting in audible sound. The system is aimed at enhancing the users’ personal audio space, therefore the measurements are performed using the Head and Torso Simulator which provides realistic reproduction...
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Features of Nonlinear Sound Propagation in Vibrationally Excited Gases
PublikacjaWeakly nonlinear sound propagation in a gas where molecular vibrational relaxation takes place is studied. New equations which govern the sound in media where the irreversible relaxation may take place are derived and discussed. Their form depends on the regime of excitation of oscillatory degrees of freedom, equilibrium (reversible) or non-equilibrium (irreversible), and on the comparative frequency of the sound in relation to...
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Comparison of sound of organ pipes in contemporary and historical instruments
PublikacjaThe aim of this research is to examine the differences in the timbre of organ pipes’ sound between a historical and a contemporary organ instrument. The historical instrument is the Oliwa organ from Gdansk, Poland, and the contemporary one is from Kartuzy, Poland. Recordings are made of single notes played by an open labial pipe that belongs to the Principal rank. The analyses and comparison of several sound features compatible...
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Analysis of Lombard speech using parameterization and the objective quality indicators in noise conditions
PublikacjaThe aim of the work is to analyze Lombard speech effect in recordings and then modify the speech signal in order to obtain an increase in the improvement of objective speech quality indicators after mixing the useful signal with noise or with an interfering signal. The modifications made to the signal are based on the characteristics of the Lombard speech, and in particular on the effect of increasing the fundamental frequency...
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Online Sound Restoration for Digital Library Applications
PublikacjaA system for sound restoration was conceived and engineered having the following features: no special sound restoration software is needed to perform audio restoration by the user, the process of restoration employs automatic reduction of noise, wow and impulse distortions performed in the online mode, no skills in digital signal processing from the user are needed. The principles of the created system and its features as well...
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New applications of sound and vision engineering
PublikacjaMultimedia, Sound & Vision Engineering are relatively new fields within the area of science and technology, but teaching and research in this area has been carried out at Gdansk University of Technology (Gdansk, Poland) for nearly 5 decades. Current project carried-out in the Multimedia Systems Department are in the scope of the paper.
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New Aspects of Virtual Sound Source Localization Research—Impact of Visual Angle and 3-D Video Content on Sound Perception
PublikacjaThe influence of image on virtual sound source localization, called the “image proximity effect” or the “ventriloquism effect”, is a well known phenomenon. This paper focuses on other aspects related to this effect, namely the impact of the visual angle of the presented object and 3D video content on sound perception. The research conducted confirmed that the visual angle of the presented object determines the image proximity effect...
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Gesture-controlled Sound Mixing System With a Sonified Interface
PublikacjaIn this paper the Authors present a novel approach to sound mixing. It is materialized in a system that enables to mix sound with hand gestures recognized in a video stream. The system has been developed in such a way that mixing operations can be performed both with or without visual support. To check the hypothesis that the mixing process needs only an auditory display, the influence of audio information visualization on sound...
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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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A Comparison of STI Measured by Direct and Indirect Methods for Interiors Coupled with Sound Reinforcement Systems
PublikacjaThis paper presents a comparison of STI (Speech Transmission Index) coefficient measurement results carried out by direct and indirect methods. First, acoustic parameters important in the context of public address and sound reinforcement systems are recalled. A measurement methodology is presented that employs various test signals to determine impulse responses. The process of evaluating sound system performance, signals enabling...
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Stochastic resonance in measurements
PublikacjaNoise is usually associated with the negative phenomenon, hampering the measurements data and their analysis. This view has been broken in the '80s when the phenomenon of stochastic resonance (Stochastic Resonance - SR) was discovered. It is a phenomenon that occurs in nonlinear dynamic measurement systems when the selected input noise can optimize system performance. SR became a way to improve efficiency of weak signals detection....
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Sound quality metrics applied to road noise evaluation
PublikacjaRoad noise monitoring systems typically measure sound levels in specific time periods. The more insightful approach suggests to measure also the nature of noise. Sound quality of sounds such as car noise can be objectively evaluated by several parameters. One of them is psychoacoustic annoyance, described by loudness, tone color, and the temporal structure of sound. In this paper the assessment of several sound quality parameters, such...
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The vortex flow caused by sound in a bubbly liquid
PublikacjaGeneration of vorticity in the field of intense sound in a bubbly liquid in the free half-space is considered. The reasons for generation of vorticity are nonlinearity, diffraction, and dispersion. Acoustic streaming differs from that in a Newtonian fluid. Under some conditions, the vortex flow changes its direction. Conclusions concern streaming induced by a harmonic or an impulse Gaussian beam.
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Individual Characteristics and Cognitions of Students with Different Levels of Entrepreneurial Intensity
PublikacjaRESEARCH OBJECTIVE: The objective of the current paper is to verify in what way university students who declare high individual level of entrepreneurial intensity differ from those who are characterized by its intensity level. THE RESEARCH PROBLEM AND METHODS: A statistical analysis of obtained survey results was conducted. The group of research participants included 413 business students. Following statistical methods were used...
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Localization of sound sources with dual acoustic vector sensor
PublikacjaThe aim of the work is to estimate the position of sound sources. The proposed method uses a setup of two acoustic vector sensors (AVS). The intersection of azimuth rays from each AVS should indicate the position of a source. In practice, the result of position estimation using this method is an area rather than a point. This is a result of inaccuracy of the individual sensors, but more importantly, of the influence of a source...
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Automatic sound recognition for security purposes
PublikacjaIn the paper an automatic sound recognition system is presented. It forms a part of a bigger security system developed in order to monitor outdoor places for non-typical audio-visual events. The analyzed audio signal is being recorded from a microphone mounted in an outdoor place thus a non stationary noise of a significant energy is present in it. In the paper an especially designed algorithm for outdoor noise reduction is presented,...
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Effect of excitation intensity on slope stability assessed by a simplified approach
PublikacjaThe paper concerns the selection of a design accelerograms used for the slope stability assessment under earthquake excitation. The aim is to experimentally verify the Arias Intensity as an indicator of the excitation threat to the slope stability. A simple dynamic system consisting of a rigid block on a rigid inclined plane subjected to horizontal excitation is adopted as a slope model. Strong ground motions recorded during earthquakes...
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Nonlinear increase in bubbles radii caused by sound in a bubbly liquid
PublikacjaThe nonlinear interaction of acoustic and entropy modes in a bubbly liquid is considered. The reasons for interaction are both nonlinearity and dispersion. In the field of intense sound, a decrease in the mixture density is predicted. That corresponds to the well-established growth of bubbles volumes due to rectified diffusion. The nonlinear interaction of modes as a reason for a bubble to grow due to sound, is discovered. The...
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Art of Space – Art in Space / The Role of Sound Art in Public
PublikacjaThe article presents a discussion of the crossroad between art and architecture. It sketches out the theoretical and practical aspects of space revitalisation and improving its quality in the context of multisensory dimension of public spaces. The unique manifestation of art and creativity in public space could be detected and stimulated using participatory architecture, for instance interactive installations, projects related...
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"Ash" [æ] sound then and now: an overview of the current state of knowledge
PublikacjaThe objective of this article is to review the existing studies on the British Received Pronunciation “ash” [æ] sound, as well as its variations outside the United Kingdom. It starts with a short analysis of sociolinguistic aspects of the Received Pronunciation accent, then it points out the most conspicuous differences between the Received Pronunciation and General American vowel systems. Then, it presents the early beginnings...
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Non-Wave Variations in Temperature Caused by Sound in a Chemically Reacting Gas
PublikacjaA weakly nonlinear generation of non-acoustic modes in the field of sound in a gas is considered. An exotericchemical reaction of A->B type, which takes place in a gas, may be reversible or not. Two types of sound areconsidered, low-frequency and high-frequency as compared with the characteristic time of a chemical reaction.For both these cases, the governing equations of non-acoustic modes are derived and conclusions of the efficiencyof...
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Vortex flow caused by periodic and aperiodic sound in a relaxing maxwell fluid
PublikacjaThis paper concerns the description of vortex flow generated by periodic and aperiodic sound in relaxing Maxwell fluid. The analysis is based on governing equation of vorticity mode, which is a result of decomposition of the hydrodynamic equations for fluid flow with relaxation and thermal conductivity into acoustical and non-acoustical parts. The equation governing vorticity mode uses only instantaneous, not averaged over sound...
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Acoustic streaming caused by some types of aperiodic sound. Buildup of acoustic streaming
PublikacjaThe analysis of streaming caused by aperiodic sound of different types (switched on at transducer sound or sound determined by initial conditions) is undertaken. The analysis bases on analytical governing equation for streaming Eulerian velocity, which is a result of decomposition of the hydrodynamic equations into acoustic and non-acoustic parts. Its driving force (of acoustic nature) represents a sum of two terms; one is the...
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Light intensity analysis of photovoltaic parameters for perovskite solar cells
PublikacjaThe number of publications on perovskite solar cells (PSC) continues to grow exponentially. Although the efficiency of PSC is exceeded 25.5%, not every research laboratory can reproduce this result or even pass the border of 20%. Unfortunately, it is not always clear which dominating mechanism is responsible for the performance drop. Here, we develop a simple method of light intensity analysis of JV parameters allowing the understanding...
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Nonlinear Influence of Sound on the Vibrational Energy of Molecules in a Relaxing Gas
PublikacjaDynamics of a weakly nonlinear and weakly dispersive flow of a gas where molecular vibrational relaxation takes place is studied. Variations in the vibrational energy in the field of intense sound is considered. These variations are caused by a nonlinear transfer of the acoustic energy into energy of vibrational degrees of freedom in a relaxing gas. The final dynamic equation which describes this is instantaneous, it includes a...
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Studies of Nonlinear Sound Dynamics in Fluids Based on the Caloric Equation of State
PublikacjaThe sound speed and parameters of nonlinearity B/A, C/A in a fluid are expressed in terms of coefficients in the Taylor series expansion of an excess internal energy, in powers of excess pressure and density. That allows to conclude about features of the sound propagation in fluids, the internal energy of which is known as a function of pressure and density. The sound speed and parameters of nonlinearity in the mixture consisting...
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Nonlinear phenomena of small-scale sound in a gas with exponential stratification
PublikacjaThe nonlinear dynamics of perturbations, quickly varying in space, with comparatively large characteristic wavenumbers k: k>1/H, is considered. H is the scale of density and pressure reduction in unperturbed gas, as the coordinate (H is the so-called height of the uniform equilibrium gas). Coupling nonlinear equations which govern the sound and the entropy mode in a weakly nonlinear flow are derived. They describe the dynamics...
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Histogram of Gradients with Cell Average Intensity for Human Detection
PublikacjaThe modification of the descriptor in human detector using Histogram of Oriented Gradients and support vector machine is presented. The proposed modification requires inserting the average cell intensitiesresulting with the increase of the length of the descriptor from 3780 to 4200 values, but it is easy to compute and instantly gives 14-26% of miss rate improvement at 10^-4 False Positives Per Window (FPPW). The modification...
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Sound Art and Architecture: New Horizons for Architecture and Urbanism
PublikacjaThe article discusses the crossroad between art and architecture. It sketches out the theoretical and practical aspects of involving art into architecture and multisensory dimensions of space. The analysis is based on examples of innovative experimental activities for architecture: educational projects such as workshops, seminars and courses, combining art and architecture, with special emphasis on sound art, and the consequences...
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Acceleration of decision making in sound event recognition employing supercomputing cluster
PublikacjaParallel processing of audio data streams is introduced to shorten the decision making time in hazardous sound event recognition. A supercomputing cluster environment with a framework dedicated to processing multimedia data streams in real time is used. The sound event recognition algorithms employed are based on detecting foreground events, calculating their features in short time frames, and classifying the events with Support...
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Import Intensity of Production, Tasks and Wages: Microlevel Evidence for Poland.
PublikacjaObjective: This article relates to recent literature on labour market consequences of production fragmentation within Global Value Chains, analysed in the presence of workers’ heterogeneity and differences in the task content of jobs. The main aim is to assess if there is a relationship between wages of Polish workers and the degree of Polish production dependence on imported inputs. Research Design & Methods: Using microdata from...
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Method of Monitoring of the Grinding Process with Lapping Kinematics Using Audible Sound Analysis
PublikacjaUtilising microphones as audible sound sensors for monitoring a single-side grinding process with lapping kinematics is presented in the paper. The audible sound generated during grinding depended on the cutting properties of electroplated tools with D107 diamond grains and different thicknesses of the nickel bond. The tool wear affected the obtained technological effects such as material removal rate and the surface roughness...
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Comparison of two methods of sound extraction from guitar string video recordings
PublikacjaA comparison of two sound extraction methods from guitar string video recordings is presented in the paper. A brief overview of highframe rate camera technology and possible applications are included. The method using the image analysis from two such cameras is presented. The cameras are placed at the angle of 90 degrees for recording the image in three planes. The results achieved...
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Acoustic Streaming Induced by Periodic and Aperiodic Sound in a Bubbly Liquid
PublikacjaThe vortex ow which follows intense sound propagating in a bubbly liquid, is considered. The reasons for acoustic streaming are both nonlinearity and dispersion. That makes streaming especial as compared with that in a Newtonian uid. Conclusions concern the vortex ow induced in a half-space by initially harmonic or impulse Gaussian beam. The vortex ow recalls a turbulent ow with increasing in time number of small-scale vortices...
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Field measurements
PublikacjaThe article presents the scope and methodologies used in the course of geodetic measurements accompanying archaeological excavations in the area of the Wisłoujście Fortress in Gdańsk
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Higher harmonics of the intensity modulated Photocurrent/Photovoltage spectroscopy response - a tool for studying photoelectrochemical nonlinearities
PublikacjaIn this work, a higher harmonic analysis (HHA) of the intensity modulated photocurrent/photovoltage (IMPS/IMVS) spectroscopy data is proposed as a potent tool for studying nonlinear phenomena in photoelectrochemical and photovoltaic systems. Analytical solutions of kinetic equations were constructed for cases of single and double resonance accounting for various sources of higher harmonics. These sources correspond to the physical...
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Research of the changeability of the vessels traffic intensity of inland waterways – case study for Lower Vistula
PublikacjaThe article presents an analysis of the changeability of traffic intensity of inland waterway vessels in the Vistula Delta. The concept of traffic intensity was defined, traffic flows and disturbances were identified in the studied area. The characteristics of the inland waterway traffic model are presented. The results of the analysis indicate the need to carry out modernization of inland waterways for the needs of inland waterway...
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Advanced sensitivity analysis of the impact of the temporal distribution and intensity of rainfall on hydrograph parameters in urban catchments
PublikacjaKnowledge of the variability of the hydrograph of outflow from urban catchments is highly important for measurements and evaluation of the operation of sewer networks. Currently, hydrodynamic models are most frequently used for hydrograph modeling. Since a large number of their parameters have to be identified, there may be problems at the calibration stage. Hence, sensitivity analysis is used to limit the number of parameters....
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A Regular Expression Matching Application with Configurable Data Intensity for Testing Heterogeneous HPC Systems
PublikacjaModern High Performance Computing (HPC) systems are becoming increasingly heterogeneous in terms of utilized hardware, as well as software solutions. The problems, that we wish to efficiently solve using those systems have different complexity, not only considering magnitude, but also the type of complexity: computation, data or communication intensity. Developing new mechanisms for dealing with those complexities or choosing an...
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Sacral sound-engineering
PublikacjaOrganologic and campanologic acoustical problems due to applications to sacral objects are characterized on ground of numerous reviewed publications and engineering reports. Participations of several involved research centres, mostly Polish, at solving these problems are evaluated. Some desirable future developments are indicated. Appendices bring examples of documentation on selected investigated objects.
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THE EFFECT OF DRYING INTENSITY ON THE COLOR CHANGES OF PINE WOOD (PINUS SYLVESTRIS L.)
PublikacjaThe effect of the selection of drying process parameters on the color change of Scots pine wood (Pinus Sylvestris L.) is presented. In this work the experimental studies have been performed. The research focused on the influence of drying intensity on the changes of color after drying process. Intensity of drying process was determined on the basis of the average drying gradient. To determine the color of wood before and after...