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Tytuł:
Design, Manufacture and Characterization of an Acoustic Barrier Made of Multi-Phenomena Cylindrical Scatterers Arranged in a Fractal-Based Geometry
Autorzy:
Casteneira-Ibanez, S.
Rubio, C.
Romero-Garcia, V.
Sanchez-Perez, J. V.
Garcia-Raffi, L. M.
Powiązania:
https://bibliotekanauki.pl/articles/176662.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
acoustic arrays
acoustic attenuation
acoustic wave absorption
acoustic wave scattering
phononic crystals
acoustic barrier
physical effect of sound
Opis:
In this work we present the design and the manufacturing processes, as well as the acoustics standard- ization tests, of an acoustic barrier formed by a set of multi-phenomena cylindrical scatterers. Periodic arrangements of acoustic scatterers embedded in a fluid medium with different physical properties are usually called Sonic Crystals. The multiple scattering of waves inside these structures leads to attenuation bands related to the periodicity of the structure by means of Bragg scattering. In order to design the acoustic barrier, two strategies have been used: First, the arrangement of scatterers is based on fractal geometries to maximize the Bragg scattering; second, multi-phenomena scatterers with several noise con- trol mechanisms, as resonances or absorption, are designed and used to construct the periodic array. The acoustic barrier reported in this work provides a high technological solution in the field of noise control.
Źródło:
Archives of Acoustics; 2012, 37, 4; 455-462
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling and Designing Acoustical Conditions of the Interior – Case Study
Autorzy:
Kostek, B.
Laskowski, S.
Mizgier, K.
Powiązania:
https://bibliotekanauki.pl/articles/176652.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
acoustic field analysis
acoustic field modeling
acoustic conditions measurements
acoustic conditions analysis
sound reinforcement system design
Opis:
The primary aim of this research study was to model acoustic conditions of the Courtyard of the Gdańsk University of Technology Main Building, and then to design a sound reinforcement system for this interior. First, results of measurements of the parameters of the acoustic field are presented. Then, the comparison between measured and predicted values using the ODEON program is shown. Collected data indicate a long reverberation time which results in poor speech intelligibility. Then, a thorough analysis is perform to improve the acoustic properties of the model of the interior investigated. On the basis of the improved acoustic model two options of a sound reinforcement system for this interior are proposed, and then analyzed. After applying sound absorbing material it was noted that the predicted speech intelligibility increased from bad/poor rating to good category.
Źródło:
Archives of Acoustics; 2016, 41, 3; 473-484
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Deagglomeration and Coagulation of Particles in Liquid Metal Under Ultrasonic Treatment
Autorzy:
Kudryashova, Olga
Vorozhtsov, Alexander
Danilov, Pavel
Powiązania:
https://bibliotekanauki.pl/articles/176746.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
acoustic field
ultrasonic processing
metal melt
nanoparticles
acoustic coagulation
cavitation
acoustic deagglomeration
Opis:
Ultrasonic processing in the cavitation mode is used to produce the composite materials based on the metal matrix and reinforcing particles of micro- and nano-sizes. In such a case, the deagglomeration of aggregates and the uniform distribution of particles are the expected effects. Although the particles can not only fragment in the acoustic field, they also can coagulate, coarsen and precipitate. In this paper, a theoretical study of processes of deagglomeration and coagulation of particles in the liquid metal under ultrasonic treatment is made. The influence of various parameters of ultrasound and dispersion medium on the dynamics of particles in the acoustic field is considered on the basis of the proposed mathematical model. The criterion of leading process (coagulation or deagglomeration) has been proposed. The calculated results are compared with the experimental ones known from the scientific literature.
Źródło:
Archives of Acoustics; 2019, 44, 3; 543-549
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pressure field in a plane layer
Autorzy:
Baranowska, A.
Powiązania:
https://bibliotekanauki.pl/articles/331904.pdf
Data publikacji:
2010
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
acoustic waves propagation
acoustic waves
waves generation
Opis:
The paper presents results of analytical and numerical investigations of a plane acoustic waves propagation through a plane layer surrounded by another medium. The waves generation problem is discussed. The mathematical model of the pressure propagation in the layer is proposed. Propagated through the layer changes in pressure, the reflected and transmitted waves were studied. Some results of numerical investigations are presented.
Źródło:
Hydroacoustics; 2010, 13; 9-16
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of Vector Sensors to Acoustic Surveillance of a Public Interior Space
Autorzy:
Łopatka, K.
Kotus, J.
Czyżewski, A.
Powiązania:
https://bibliotekanauki.pl/articles/176963.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
sound localization
acoustic vector sensors
acoustic events
Opis:
A method for precise sound sources detection and localization in interiors is presented. Acoustic vector sensors, which provide multichannel output signals of acoustic pressure and particle velocity were employed. Methods for detecting acoustic events are introduced. The algorithm for localizing sound events in the audience is presented. The system set up in a lecture hall, which serves as a demonstrator of the proposed technology, is described. The accurracy of the proposed method is evaluated by the described measurement results. The analysis of the results is followed by conclusions pertaining the usability of the proposed system. The concept of the multimodal audio-visual detection of events in the audience is also introduced.
Źródło:
Archives of Acoustics; 2011, 36, 4; 851-860
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of the Acoustic Suitability of an Open Plan Office Based on STI and DL2 Simulations
Autorzy:
Passero, C. R. M.
Zannin, P. H. T.
Powiązania:
https://bibliotekanauki.pl/articles/178137.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
open plan offices
acoustic evaluation
acoustic improvement
Opis:
Many business offices around the world are organized as open plan offices. Therefore, studies about the acoustic comfort of the people who work in them have become increasingly important. The focus of this work is the acoustic evaluation of an open plan office combining several architectural characteristics and levels of ambient noise. This evaluation was performed through a computational model calibrated from a real office. The rate of spatial decay of sound pressure levels per distance doubling (DL2) and the speech transmission index (STI) were simulated for the acoustic evaluation of the office, allowing for the determination of the radius of distraction (rD). These parameters were simulated for 6 situations using different floor and ceiling covering materials and inserting or withdrawing screens between workstations. In addition, STI and rD were simulated under two conditions of ambient noise. The results indicated that the DL2 and rD are adequate acoustic parameters for the acoustic evaluation and improvement of an open plan office. The DL2 was strongly influenced by the presence or absence of screens between workstations and by the ceiling covering material. The rD was more sensitive to changes in ambient noise.
Źródło:
Archives of Acoustics; 2012, 37, 2; 237-243
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical modeling of transient acoustic field using finite element method
Autorzy:
Koudela, L.
Jansa, J.
Karban, P.
Powiązania:
https://bibliotekanauki.pl/articles/377945.pdf
Data publikacji:
2013
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
acoustic field
finite element method
acoustic wave
Opis:
Numerical solution of acoustic wave equation in the time domain is performed. The appropriate mathematical model is described by the partial differential wave equation supplemented with appropriate boundary conditions. The goal is to obtain the time evolution of the distribution of acoustic pressure, which can serve as the basis for the solution of various subsequent problems. The paper discusses the results of the numerical analysis of a semicircular acoustic diffuser in a free field, realized by a fully adaptive higher-order finite element method implemented in our own codes Agros2D and Hermes. The results are compared with the data obtained by the commercial code Comsol Multiphysics.
Źródło:
Poznan University of Technology Academic Journals. Electrical Engineering; 2013, 73; 155-160
1897-0737
Pojawia się w:
Poznan University of Technology Academic Journals. Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sources of the variability of acoustic response of clupeoids in the Baltic
Autorzy:
Orlowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/331596.pdf
Data publikacji:
2008
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
Baltic
variability of acoustic response
acoustic information
Opis:
Acoustic information, collected in the form of calibrated measurements of integrated echo energies, has been applied at the Sea Fisheries Institute since 1981 to examine the relationships between clupeoids distribution in the Baltic and the relevant environmental factors. Data were collected during different seasons for each elementary distance unit (EDSU) at standardised depth intervals and compared to the values of selected environmental parameters measured in parallel. Acoustic, biological and hydrological data were correlated temporally and spatially, then transferred to a comprehensive database, thereby enabling the 4D analysis of the factors characterising a wide range of fish behaviour. Selected characteristics describe the variability of environmental factors during the short- and long-term life cycles of clupeoids. Apart from the analysis of abiotic factors, specially prepared cross-sections of the herring in different stages of gonad maturity are presented. The aspects of variability have been described for their inclusion in the measuring and modelling herring and sprat target strength, particularly under the specific circumstances of the Baltic Sea.
Źródło:
Hydroacoustics; 2008, 11; 313-328
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the Nonlinear Distortions of Sound and its Coupling with Other Modes in a Gaseous Plasma with Finite Electric Conductivity in a Magnetic Field
Autorzy:
Perelomova, A.
Powiązania:
https://bibliotekanauki.pl/articles/177768.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
magnetoacoustics
nonlinear wave phenomena
finite electrical conductivity
acoustic dispersion
acoustic heating
acoustic streaming
Opis:
Nonlinear phenomena of the planar and quasi-planar magnetoacoustic waves are considered. We Focus on deriving of equations which govern nonlinear excitation of the non-wave motions by the intense sound in initially static gaseous plasma. The plasma is treated as an ideal gas with finite electrical conductivity permeated by a magnetic field orthogonal to the trajectories of gas particles. This introduces dispersion of a flow. Magnetoacoustic heating and streaming in the field of periodic and aperiodic magnetoacoustic perturbations are discussed, as well as generation of the magnetic perturbations by sound. Two cases, corresponding to magnetosound perturbations of low and high frequencies, are considered in detail.
Źródło:
Archives of Acoustics; 2016, 41, 4; 691-699
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Acoustic seabed classification applied to Baltic benthic habitat studies: a new approach
Autorzy:
Orlowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/48659.pdf
Data publikacji:
2007
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
ecology
bottom habitat
acoustic method
acoustic seabed classification
Baltic Sea
bathymetry
acoustic classification
Źródło:
Oceanologia; 2007, 49, 2
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal Self-Action of Acoustic Beams Containing Several Shock Fronts
Autorzy:
Perelomova, A.
Powiązania:
https://bibliotekanauki.pl/articles/177213.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
thermal self-focusing
acoustic beam
acoustic wave with discontinuity
acoustic shock waves
thermal lens
Opis:
Thermal self-action of an acoustic beam with one discontinuity or several shock fronts is studied in a Newtonian fluid. The stationary self-action of a single sawtooth wave with discontinuity (or some integer number of these waves), symmetric or asymmetric, is considered in the cases of self-focusing and self-defocusing media. The results are compared with the non-stationary thermal self-action of the periodic sound. Thermal self-action of a single shock wave which propagates with the various speeds is considered.
Źródło:
Archives of Acoustics; 2015, 40, 4; 539-546
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimation of Acoustic Impedance for Surfaces Delimiting the Volume of an Enclosed Space
Autorzy:
Piechowicz, J.
Czajka, I.
Powiązania:
https://bibliotekanauki.pl/articles/177215.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
acoustic impedance
acoustic measurements
numerical methods
sound field
Opis:
Several methods can be applied for analyses of the acoustic field in enclosed rooms namely: wave propagation, geometrical or statistical analysis. The paper presents problems related to application of the boundary elements method to modelling of acoustic field parameters. Experimental and numerical studies have been combined for evaluation of acoustic impedance of the material used for the walls of a model room. The experimental studies have been carried out by implementing a multichannel measuring system inside the constructed model of an industrial room. The measuring system allowed simultaneous measurements of the source parameters – the loudspeaker membrane vibration speed, the acoustic pressure values in reception points located inside the model space as well as phase shifts between signals registered in various reception points. The numerical modelling making use of the acoustic pressure values measured inside the analyzed space allowed determination of requested parameters of the surface at the space boundary.
Źródło:
Archives of Acoustics; 2012, 37, 1; 97-102
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ oprzyrządowania pomiarowego na rozkład pola akustycznego
An influence of the measuring instruments on the acoustic field distribution
Autorzy:
Olszewski, R.
Powiązania:
https://bibliotekanauki.pl/articles/250988.pdf
Data publikacji:
2013
Wydawca:
Instytut Naukowo-Wydawniczy TTS
Tematy:
pole akustyczne
pomiary akustyczne
acoustic field
acoustic measurement
Opis:
Artykuł dotyczy badań modelowych wpływu oprzyrządowania pomiarowego na pole akustyczne w którym się znajdują. Przedstawiono wyniki dla dwóch obiektów różniących się kształtem, które są wymieniane jako możliwe do wykorzystania w charakterze urządzenia pozwalającego przemieszczać elementy toru pomiarowego.
The paper concerns a model based research of an impact of a measurement equipment on the acoustic field it is located in. The results for the two objects that differ in shape, and both are possible to use as a device allowing to move the measurement path elements, are presented.
Źródło:
TTS Technika Transportu Szynowego; 2013, 10; 1117-1124, CD
1232-3829
2543-5728
Pojawia się w:
TTS Technika Transportu Szynowego
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Acoustic Metamaterials
Autorzy:
Sztyler, Bartłomiej
Strumiłło, Paweł
Powiązania:
https://bibliotekanauki.pl/articles/2141685.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
acoustic metamaterials
acoustic metasufraces
tunability
3D printing
Opis:
This review article is concerned with metamaterials, i.e. specifically engineered structures with special properties for interaction with sounds. The research on and practical design of these materials have gained momentum in the last decade, when 3D printing techniques provided the possibility to fabricate such geometrically complex structures. We briefly describe the history of research on AMMs and group them into active and passive metamaterials. For each of these groups of AMMs, we discuss the most notable construction achievements and outline the main applications. We conclude this review with a discussion of possible directions for further research and main applications of AMMs such as noise attenuation, acoustic lens, and the cloaking phenomenon.
Źródło:
Archives of Acoustics; 2022, 47, 1; 3-14
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Effects of Trunk Cavity and Air-Gaps in the Acoustic Response of a Passenger Vehicle
Autorzy:
Oktav, A.
Powiązania:
https://bibliotekanauki.pl/articles/950216.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
acoustic coupling
acoustic eigenfrequencies
acoustic modes
acoustic response
air-gap
cabin cavity
Helmholtz resonator
passenger vehicle
trunk cavity
wave number
Opis:
The effects of additional cavities and air-gaps in the acoustic response of a passenger vehicle are investigated. It is observed that the cabin cavity and the trunk cavity of the passenger vehicle are connected through an aperture in the rear seat. In the trunk cavity of the vehicle, there are two more air-gaps which are designed as countermeasures to trunk lid slam noise. It is established that acoustic modes and acoustic eigenfrequencies of the vehicle are altered through the trunk cavity and its air-gaps. To develop an analytical solution, the actual acoustic cavity is simplified into a rectangular shape. In the analytical solution, the coupling of trunk and cabin cavities is considered. It is shown that the computational analysis results match well with the results of the analytical solution proposed. Further, the resonator effect of air-gaps present in the trunk cavity is examined.
Źródło:
Archives of Acoustics; 2017, 42, 3; 433-440
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Normative measurements of noise at CNC machines work stations
Autorzy:
Mika, D.
Józwik, J.
Powiązania:
https://bibliotekanauki.pl/articles/103079.pdf
Data publikacji:
2016
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
noise
noise measurement
acoustic pressure
acoustic absorption
CNC machines
Opis:
Minimisation of noise at a workstation is among fundamental tasks for maintaining safety at work, both in terms of health (the auditory system in particular) as well as work comfort. Thus, it is very important to systematically monitor noise levels by carrying out reliable measurements at a workstation. The method of performing noise measurements at workstations of specific machines is normalised so the results of such measurements for different machines is comparable. This paper presents noise measurements for DMC 635 numerically controlled milling machine, performed in accordance with PN ISO 230-5:2002 norm. The results showed that the level of noise at the operator’s workstation significantly exceeds the norm at certain machining parameters. The results of tests are concluded as detailed recommendation for the CNC machine tool operator to use hearing protection when at work.
Źródło:
Advances in Science and Technology. Research Journal; 2016, 10, 30; 138-143
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Diagnostics of Rotor Damages of Three-Phase Induction Motors Using Acoustic Signals and SMOFS-20-EXPANDED
Autorzy:
Glowacz, A.
Powiązania:
https://bibliotekanauki.pl/articles/177944.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
induction motor
machine
acoustic signal
acoustic emission
fault diagnostics
Opis:
A fault diagnostics system of three-phase induction motors was implemented. The implemented system was based on acoustic signals of three-phase induction motors. A feature extraction step was performed using SMOFS-20-EXPANDED (shortened method of frequencies selection-20-Expanded). A classification step was performed using 3 classifiers: LDA (Linear Discriminant Analysis), NBC (Naive Bayes Classifier), CT (Classification Tree). An analysis was carried out for incipient states of three-phase induction motors measured under laboratory conditions. The author measured and analysed the following states of motors: healthy motor, motor with one faulty rotor bar, motor with two faulty rotor bars, motor with faulty ring of squirrel-cage. Measured and analysed states were caused by natural degradation of parts of the machine. The efficiency of recognition of the analysed states was good. The proposed method of fault diagnostics can find application in protection of three-phase induction motors.
Źródło:
Archives of Acoustics; 2016, 41, 3; 507-515
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Long-Term Comparative Evaluation of Acoustic Climate in Selected Schools Before and After Acoustic Treatment
Autorzy:
Kotus, J.
Szczodrak, M.
Czyżewski, A.
Kostek, B.
Powiązania:
https://bibliotekanauki.pl/articles/177966.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
noise measurement
acoustic climate evaluation
acoustic treatment
noise dose
Opis:
The results of long-term continuous noise measurements in two selected schools are presented in the paper. Noise characteristics were measured continuously there for approximately 16 months. Measurements started eight months prior to the acoustic treatment of the school corridors of both schools. An evaluation of the acoustic climates in both schools, before and after the acoustic treatment, was performed based on comparison of these two periods of continuous measurements. The autonomous noise monitoring stations, engineered at the Multimedia Systems Department of the Gdansk University of Technology were used for this purpose. Investigations of measured noise, especially its influence on hearing sense, assessed on ground of spectral analyses in critical bands, is discussed. Effects of occupational noise exposure, including the Temporary Threshold Shift simulation, are determined. The correlation of the above said measurement results with respective instantaneous noise levels is discussed, and concluding remarks are presented. Some additional indicators such as air pollution or video analysis aiming at the analysis of corridor occupancy are also measured. It should be remembered that excessive noise, or air pollution may be evidence of a dangerous event and may pose health risks.
Źródło:
Archives of Acoustics; 2010, 35, 4; 551-564
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of Lithuanian and Polish Consonant Phonemes Based on Acoustic Analysis – Preliminary Results
Autorzy:
Korvel, Gražina
Kurasova, Olga
Kostek, Bożena
Powiązania:
https://bibliotekanauki.pl/articles/177441.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
acoustic analysis
consonant phonemes
acoustic parameters
machine learning methods
Opis:
The goal of this research is to find a set of acoustic parameters that are related to differences between Polish and Lithuanian language consonants. In order to identify these differences, an acoustic analysis is performed, and the phoneme sounds are described as the vectors of acoustic parameters. Parameters known from the speech domain as well as those from the music information retrieval area are employed. These parameters are time- and frequency-domain descriptors. English language as an auxiliary language is used in the experiments. In the first part of the experiments, an analysis of Lithuanian and Polish language samples is carried out, features are extracted, and the most discriminating ones are determined. In the second part of the experiments, automatic classification of Lithuanian/English, Polish/English, and Lithuanian/Polish phonemes is performed.
Źródło:
Archives of Acoustics; 2019, 44, 4; 693-707
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Technique for Measuring Spatial Distribution of the Surface Acoustic Wave Velocity in Metals
Autorzy:
Mokryy, O.
Tsyrulnyk, O.
Powiązania:
https://bibliotekanauki.pl/articles/177231.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ultrasound
surface acoustic waves
acoustic wave velocity
spatial resolution
Opis:
In this paper a possibility of determining a local velocity of the surface acoustic Rayleigh waves using a transducer, with the rigidly connected emitting and receiving parts, is considered. A problem on spatial resolution of such a transducer for investigation of inhomogeneous specimens is also examined. A high spatial resolution can be obtained due to the transducer displacement by a value less than the distance between the emitting and receiving parts. It is shown that in this case it is not necessary to measure the transducer displacement with a high accuracy for precise determination of the velocity. Such an effect is obtained through measuring the velocity of surface waves in one local region of the specimen with respect to the other. The criterion for optimal spatial resolution selection during spatially inhomogeneous specimens study is also proposed. The proposed criterion use is illustrated on the example of the determination of spatial distribution of the surface acoustic velocity in a steel specimen subjected to inhomogeneous plastic deformation.
Źródło:
Archives of Acoustics; 2016, 41, 4; 741-746
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of nonlinear constants from results of acoustic measurements. Regularization of problem
Autorzy:
Leble, S. B.
Vereshchagin, D. A.
Vereshchagina, I. S.
Powiązania:
https://bibliotekanauki.pl/articles/332067.pdf
Data publikacji:
2003
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
acoustic measurements
regularization
Opis:
The method of nonlinear constants B/A and C/A determination is discussed. It bases on comparison of experimental results of acoustic signal propagation with results of theoretical investigation of this problem. It is shown, that this problem, in general case, is ill-posed. So we use methods of ill-posed problem solution regularization. The values of the constants, which were extracted using this method, are in good accordance with estimations by other authors.
Źródło:
Hydroacoustics; 2003, 6; 159-166
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pressure Level Standard Deviation at Low Frecuencies: Effect of the Wall Vibrational Field
Autorzy:
Navacerrada, M. A.
Diaz, C.
Pedrero, A.
Powiązania:
https://bibliotekanauki.pl/articles/176711.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
building acoustic
uncertainty
Opis:
Knowledge of the uncertainty of measurement of testing results is important when results have to be compared with limits and specifications. In the measurement of sound insulation following standards ISO 140-4 and 140-5 the uncertainty of the final magnitude is mainly associated to the average sound pressure levels L1 and L2 measured. However, the study of sound fields in enclosed spaces is very difficult: there are a wide variety of rooms with different sound fields depending on factors as volume, geometry and materials. A parameter what allows us to quantify the spatial variation of the sound pressure level is the standard deviation of the pressure levels measured at the different positions of the room. Based on the analysis of this parameter some results have been pointed out: we show examples on the influence of the microphone positions and the wall characteristics on the uncertainty of the final magnitudes mainly at the low frequencies regime. In this line, we propose a theoretical calculus of the standard deviation as a combined uncertainty of the standard deviation already proposed in the literature focused in the room geometry and the standard deviation associated to the wall vibrational field.
Źródło:
Archives of Acoustics; 2012, 37, 4; 561-569
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sensitivity of echo envelope fractal dimension to bottom type and bottom depth - numerical results
Autorzy:
Łubniewski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/332051.pdf
Data publikacji:
2003
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
acoustic
seafloor
hydroacoustics
Opis:
The presented results are a part of those obtained within the author's latest work on application of normal incidence methods in acoustic seafloor characterisation. The work included both theoretical and experimental studies on selection of appropriate methods of seafloor echo processing and feature extraction for characterisation of the bottom type, especially, the study of the usefulness of several echo parameters like fractal dimension or statistical moments of the echo envelope. In this paper, the simulation results of the echo envelope fractal dimension dependence on bottom type and bottom depth are presented. They show that to same extent, fractal dimension of an echo may be useful for bottom identification even in a case of varying depth, however, more detailed, theoretical as well as experimental studies are needed.
Źródło:
Hydroacoustics; 2003, 6; 195-198
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The 8AE-PD computer measurement system for registration and analysis of acoustic emission signals generated by partial discharges in oil power transformers
Autorzy:
Witos, Franciszek
Opilski, Zbigniew
Szerszeń, Grzegorz
Setkiewicz, Maciej
Powiązania:
https://bibliotekanauki.pl/articles/220623.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
acoustic emission
partial discharge
multichannel system
acoustic signal detection
acoustic signal processing
signal analysis
voltage preamplifier
Opis:
A computer measurement system, designed and built by authors, dedicated to location and description of partial discharges (PD) in oil power transformers examined by means of the acoustic emission (AE) method is presented. The measurement system is equipped with 8 measurement channels and ensures: monitoring of signals, registration of data in real time within a band of 25-1000 kHz in laboratory and real conditions, basic and advanced analysis of recorded signals. The basic analysis carried out in the time, frequency and time-frequency domains deals with general properties of the AE signals coming from PDs. The advanced analysis, performed in the discrimination threshold domain, results in identification of signals coming from different acoustic sources as well as location of these sources in the examined transformers in terms of defined by authors descriptors and maps of these descriptors on the side walls of the tested transformer tank. Examples of typical results of laboratory tests carried out with the use of the built-in measurement system are presented.
Źródło:
Metrology and Measurement Systems; 2019, 26, 2; 403-418
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sound Behaviour of Concrete Churches. The Church of Santa Cruz de Oleiros
Autorzy:
Bueno, A. M.
Galindo, M.
León, A. L.
Powiązania:
https://bibliotekanauki.pl/articles/177435.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
room acoustics
concrete
worship acoustics
acoustic simulation
acoustic energy
intelligibility
Opis:
The church of Santa Cruz de Oleiros, Spain (1967) shows architect Miguel Fisac’s perception of sacred space after the Second Vatican Council. In this place of worship, the architect responded to the new liturgical guidelines combining geometry and architectural forms with the material of the moment, concrete. However, ordinary religious celebrations reveal acoustic deficiencies for the main use of the building. This fact is corroborated by acoustic measurements in situ. With a methodology that uses simulation techniques for the sound field, the analysis of the current acoustic behaviour of the room will serve as the basis for an acoustic rehabilitation proposal aimed at improving the acoustic conditions and so, the functionality of the church.
Źródło:
Archives of Acoustics; 2018, 43, 2; 297-306
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the Influencing Factors of the Acoustic Performance of the Muffler Considering Acoustic-structural Coupling
Autorzy:
Zhao, Bo
Li, He
Powiązania:
https://bibliotekanauki.pl/articles/31339942.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
acoustic performance
muffler
acoustic-structural coupling
transmission loss
mode
optimisation
Opis:
In the calculation of the acoustic performance of mufflers, the walls of mufflers are usually treated rigidly without considering the acoustic-structural coupling, but the results so calculated differ significantly from the actual situation. Based on the basic equations, the article derives the finite element equations of the muffler system while considering the acoustic-structural coupling effect and theoretically analyses the connection between the acoustic-structural coupling system and the structural and acoustic modes. The structural and acoustic modes of the muffler are calculated and the reasons for the mutation of the transmission loss curve of the muffler when the acoustic-structural coupling is considered are analysed. The results show that the acoustic-structural coupling is the result of the interaction between the structure and the air inside the expansion chamber under acoustic excitation, which manifests mutations in the sound pressure inside the muffler in some frequency bands. Then, using a single-chamber muffler as an example, the transmission loss is used to characterise the performance of the muffler. The effects of different factors such as shell thickness, structure, porous media material lining, and restraint method on the acoustic-structural coupling effect of the muffler are analysed, and the structure of a double-chamber muffler is successfully optimised according to the conclusions.
Źródło:
Archives of Acoustics; 2022, 47, 4; 479-490
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Krzywa rozkładu dźwieku w przestrzeni jako parametr charakteryzujacy akustykę pomieszczenia
Spatial decay curve as characteristic acoustic parameter of room
Autorzy:
Jabłoński, M.
Wątły, J.
Powiązania:
https://bibliotekanauki.pl/articles/363034.pdf
Data publikacji:
2007
Wydawca:
Instytut Fizyki Budowli Katarzyna i Piotr Klemm
Tematy:
akustyka pomieszczeń
krzywe rozkładu dźwięku
ciśnienie akustyczne
właściwości akustyczne pomieszczeń
acoustic of room
acoustic pressure
acoustic propertis
Opis:
W artykule przedstawiono wyniki obliczeń symulacyjnych spadku wartości ciśnienia akustycznego w przestrzeni z podwojeniem odległości DL2 sali konferencyjnej i audytorium oraz weryfikację pomiarową tego pararnetru w obiektach rzeczywistych.
This paper presents the results of spatial decay in conference room and auditorium, obtained using numerical techniques. They were compared with measurements data of this parameter in real rooms.
Źródło:
Fizyka Budowli w Teorii i Praktyce; 2007, T. 2; 105-108
1734-4891
Pojawia się w:
Fizyka Budowli w Teorii i Praktyce
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Metrological capabilities of the acoustic testing laboratory - small anechoic chamber at the AGH Department of Mechanics and Vibroacoustics
Autorzy:
Kłaczyński, Maciej
Wszołek, Wiesław
Powiązania:
https://bibliotekanauki.pl/articles/2202424.pdf
Data publikacji:
2022
Wydawca:
Politechnika Poznańska. Instytut Mechaniki Stosowanej
Tematy:
anechoic chamber
acoustic testing laboratories
acoustic wedges
acoustic metrology
komora bezodbiciowa
laboratoria akustyczne
kliny akustyczne
metrologia akustyczna
Opis:
The small anechoic chamber is part of the research facilities of the Department of Mechanics and Vibroacoustics in AGH University of Science and Technology in Krakow and is a room corresponding to a free field, whose walls, ceiling and floor provide both very good sound absorption and isolation from external interference. The dimensions of the free space inside the chamber are 4.4 m x 3.8 m. x 3.6 m. The chamber was commissioned in the mid-1980s and has not undergone upgrades since. In December 2021, the upgrade of the small anechoic chamber was completed. As particularly important was the replacement of 5.5 thousand pieces of acoustic wedges made of polyurethane foam, which due to the aging process lost their sound-absorbing properties, for wedges made of mineral wool with glass fiber, adjustment of lighting inside the chamber to current standards, as well as equipping the chamber with a signal crossover and devices to regulate and monitor meteorological conditions inside the chamber. The paper presents a study of the properties of the small anechoic chamber in accordance with accepted standards for this type of rooms and its current research capabilities in the field of vibroacoustics in technology and medicine.
Źródło:
Vibrations in Physical Systems; 2022, 33, 2; art. no. 2022217
0860-6897
Pojawia się w:
Vibrations in Physical Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Acoustic Rehabilitation of the Church of Santa Ana in Moratalaz, Madrid
Autorzy:
Bueno, A. M.
León, A. L.
Galindo, M.
Powiązania:
https://bibliotekanauki.pl/articles/176614.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
room acoustics
worship acoustics
acoustic simulation
sound-reinforcement
acoustic rehabilitation
Opis:
The church of Santa Ana in Moratalaz, Madrid, Spain (1965–1971), is an emblematic work of the architect Miguel Fisac. In his long career include interventions in the religious field, constituting one of the most important contributions to Spanish religious architecture of the last century. This church is a singular place of worship and architecturally significant, in which the acoustics played an important role in the configuration of the spatiality of the church. This paper studies the acoustic behaviour of the church and its relationship with its unique structural, spatial and coating material characteristics. The analysis of the current acoustic conditions, with high reverberation times (up to 6 seconds) and poor intelligibility on the audience, serve as the basis for making an acoustic rehabilitation proposal that contributes to improving the sound conditions of the building for the intended use, without distorting the spatial, formal and material aspects with which the architect conceived the project.
Źródło:
Archives of Acoustics; 2012, 37, 4; 435-446
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design of Acoustic Tubes Array and Application to Measuring Acoustic Loads in Supersonic Airflow
Autorzy:
Wei, L.
Li, M.
Fu, Q.
Fan, Y.
Yang, D.
Powiązania:
https://bibliotekanauki.pl/articles/176750.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
acoustic load
acoustic tubes array
near field measurement
supersonic airflow
Opis:
In the acoustic fatigue experiment for hypersonic vehicle in simulated harsh service environment on ground, acoustic loads on the surface of test pieces of the vehicle need to be measured. However, for the normal microphones without high temperature resistance ability, the near field sound measurement cannot be achieved. In this work, on the basis of previous researches, an acoustic tubes array is designed to achieve the near field measurement of acoustic loads on the surface of the test piece in the supersonic airflow with high temperature achieved by coherent jet oxygen lance. Firstly, the process of designing this acoustic tubes array is introduced. Secondly, the equality of phase differences at the front and at the end of the tubes is stated and proved using a phase differences test with an acoustic tubes array whose design is presented in this text; therefore, the phase differences of signals acquired by microphones can be directly applied to beamforming algorithm to determine the acoustic load source. Finally, using above mentioned acoustic tubes array, measurement of acoustic load, with and without a test piece in the supersonic airflow made by the coherent jet oxygen lance, is conducted respectively, and the measurements results are analyzed.
Źródło:
Archives of Acoustics; 2014, 39, 3; 395-402
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Using Clustering Methods for the Identification of Acoustic Emission Signals Generated by the Selected Form of Partial Discharge in Oil-Paper Insulation
Autorzy:
Borucki, S.
Łuczak, J.
Zmarzły, D.
Powiązania:
https://bibliotekanauki.pl/articles/177657.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
acoustic emission method
acoustic signals
partial discharges
insulation
power transformer
Opis:
The article presents the results concerning the use of clustering methods to identify signals of acoustic emission (AE) generated by partial discharge (PD) in oil-paper insulation. The conducted testing featured qualitative analysis of the following clustering methods: single linkage, complete linkage, average linkage, centroid linkage and Ward linkage. The purpose of the analysis was to search the tested series of AE signal measurements, deriving from three various PD forms, for elements of grouping (clusters), which are most similar to one another and maximally different than in other groups in terms of a specific feature or adopted criteria. Then, the conducted clustering was used as a basis for attempting to assess the effectiveness of identification of particular PD forms that modelled exemplary defects of the power transformer’s oil-paper insulation system. The relevant analyses and simulations were conducted using the Matlab estimation environment and the clustering procedures available in it. The conducted tests featured analyses of the results of the series of measurements of acoustic emissions generated by the basic PD forms, which were obtained in laboratory conditions using spark gap systems that modelled the defects of the power transformer’s oil-paper insulation.
Źródło:
Archives of Acoustics; 2018, 43, 2; 207-215
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Geographic information system for remote integration of diverse under-water acoustic sensor data
Autorzy:
Chybicki, A.
Kamiński, Ł.
Lubniewski, Z.
Bruniecki, K.
Kulawiak, M.
Dąbrowski, J.
Moszyński, M.
Powiązania:
https://bibliotekanauki.pl/articles/332542.pdf
Data publikacji:
2009
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
geographic information system (GIS)
acoustic sensor data
under-water acoustic
Opis:
Maritime and port areas throughout the world are exposed to many different hazards, like pollution, terrorism and natural disasters. Early detection, identification and preparation of appropriate response strategies is especially important in the case of semi-enclosed basins like the Baltic Sea, mainly due to the marine ecosystems' continuous absorption of pollutants including oil, heavy metals and chemicals. Many of those agents are characterised by great toxicity and cause devastation of the natural environment. The huge development in the information technology provides the means and possibilities for much faster and more efficient access to survey data, allowing their remote, nearly real-time management, processing and visualisation. Several approaches and techniques of measurements are available in marine environment monitoring. These consist of direct sampling, airborne and satellite imagery, hydrological measurements using CTD probes, remote sensing with the use of electromagnetic waves, acoustic methods based on the data acquired by multibeam systems, side-scan sonars and singlebeam echosounders.
Źródło:
Hydroacoustics; 2009, 12; 17-24
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Problemy związane z jakością akustyczną pomieszczeń typu „open space”
Problems with the quality of acoustic for open-plan offices
Autorzy:
Jabłoński, M.
Kruczek, A.
Powiązania:
https://bibliotekanauki.pl/articles/362559.pdf
Data publikacji:
2015
Wydawca:
Instytut Fizyki Budowli Katarzyna i Piotr Klemm
Tematy:
open space
jakość akustyczna
parametry akustyczne
acoustic quality
acoustic parameters
Opis:
W pracy przeanalizowano problemy związane z jakością akustyczną biur typu „open space” w obiektach użyteczności publicznej. Przedstawiono wartości głównego parametru związanego z jakością akustyczną jakim jest czas pogłosu. Następnie oceniono komfort w analizowanym biurze na podstawie takich wskaźników jak: zanik przestrzenny dźwięku wraz z podwojeniem odległości D2,S (Spatial Decay Rate of Speech), poziom dźwięku mowy w odległości 4m od źródła LP,A,S,4m (A-weighted Sound Pressure Level of Speech at a distance of 4m), promień dekoncentracji rD (Distraction Distance), promień komfortu akustycznego rC (Distance of Comfort) oraz promień prywatności rP (Privacy Distance).
This paper analizys acoustics problems in open plan offices. The main room acoustics parameter, which is the reverberation time, was analyzed. Then, comfort of this office was rated based on such indicators as Speech Transmission Index STI, A-weighted Sound Pressure Level SPL(A), Spatial Decay Rate of Speech D2,S, A-weighted Sound Pressure Level of Speech at a distance of 4m Lp,A,S,4m, Distraction Distance rD, Distance of Comfort rC and Privacy Distance rp.
Źródło:
Fizyka Budowli w Teorii i Praktyce; 2015, T. 7, nr 3, 3; 23-28
1734-4891
Pojawia się w:
Fizyka Budowli w Teorii i Praktyce
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Direction Estimation and Tracking of Coherent Sources Using a Single Acoustic Vector Sensor
Autorzy:
Wajid, Mohd
Kumar, Arun
Bahl, Rajendar
Powiązania:
https://bibliotekanauki.pl/articles/176542.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
acoustic intensity
acoustic vector sensor
DOA
Direction of Arrival
FEM
Finite Element Method
tracking of acoustic source
Opis:
A single acoustic vector sensor (AVS) cannot be used to find the direction-of-arrival (DOA) of two or more coherent (fully correlated) sources. We have proposed a technique for estimating DOAs (in 2D geometry) of two simultaneous coherent sources using single AVS under the assumption that acoustic sources enter in the field sequentially. The DOA estimation has been investigated with two different configurations of AVS, each consisting of three microphones in a plane. The technique has been also applied in tracking (a) an acoustic source in the presence of stationary interfering coherent source and (b) two coherent sources when the sources are changing their locations alternatively. The experimental environment has been generated using the Finite-Element Method tool viz. COMSOL to corroborate the proposed scheme.
Źródło:
Archives of Acoustics; 2020, 45, 2; 209-219
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Creating Acoustic Maps Employing Supercomputing Cluster
Autorzy:
Czyżewski, A.
Kotus, J.
Szczodrak, M.
Powiązania:
https://bibliotekanauki.pl/articles/177400.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
noise pollution
acoustic noise monitoring
noise propagation model
supercomputing
acoustic maps
Opis:
The implemented online urban noise pollution monitoring system is presented with regard to its conceptual assumptions and technical realization. A concept of the noise source parameters dynamic assessment is introduced. The idea of noise modeling, based on noise emission characteristics and emission simulations, was developed and practically utilized in the system. Furthermore, the working system architecture and the data acquisition scheme are described. The method for increasing the speed of noise map calculation employing a supercomputer is explained. The practical implementation of noise maps generation and visualization system is presented, together with introduced improvements in the domain of continuous noise monitoring and acoustic maps creation. Some results of tests performed using the system prototype are shown. The main focus is put on assessing the efficiency of the acoustic maps created with the discussed system, in comparison to results obtained with traditional methods.
Źródło:
Archives of Acoustics; 2011, 36, 2; 395-418
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Systematic error of acoustic particle image velocimetry and its correction
Autorzy:
Mickiewicz, W.
Powiązania:
https://bibliotekanauki.pl/articles/221013.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
particle image velocimetry
acoustic measurement
acoustic particle velocity
sound field analysis
Opis:
Particle Image Velocimetry is getting more and more often the method of choice not only for visualization of turbulent mass flows in fluid mechanics, but also in linear and non-linear acoustics for non-intrusive visualization of acoustic particle velocity. Particle Image Velocimetry with low sampling rate (about 15Hz) can be applied to visualize the acoustic field using the acquisition synchronized to the excitation signal. Such phase-locked PIV technique is described and used in experiments presented in the paper. The main goal of research was to propose a model of PIV systematic error due to non-zero time interval between acquisitions of two images of the examined sound field seeded with tracer particles, what affects the measurement of complex acoustic signals. Usefulness of the presented model is confirmed experimentally. The correction procedure, based on the proposed model, applied to measurement data increases the accuracy of acoustic particle velocity field visualization and creates new possibilities in observation of sound fields excited with multi-tonal or band-limited noise signals.
Źródło:
Metrology and Measurement Systems; 2014, 21, 3; 447-460
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wokół idei ekologii akustycznej. Koncepcje i praktyki
Around the idea of acoustic ecology. Concepts and practices
Autorzy:
Losiak, Robert
Powiązania:
https://bibliotekanauki.pl/articles/667062.pdf
Data publikacji:
2017
Wydawca:
Wydawnictwo Uniwersytetu Śląskiego
Tematy:
acoustic ecology (sound ecology)
soundscape
noise
acoustic design
Raymond Murray Schafer
Opis:
The idea of acoustic ecology emerged in the sixties of the twentieth century with the work of Raymond Murray Schafer and his school of soundscape studies. The starting point was the concern for the sound environment resulting from the sense of threat from progressive civilization changes and the increase of noise. In his project work, Schafer gave emphasis to education as well as to the development of ecological acoustic design. What was another important element of the program was the research activity aimed at, among others, documenting and analysing contemporary landscapes. The ecological importance of this research arises from increasing social awareness about the cultural value of the sound environment.
Źródło:
Studia Etnologiczne i Antropologiczne; 2017, 17; 115-126
1506-5790
2353-9860
Pojawia się w:
Studia Etnologiczne i Antropologiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetoacoustic Heating of Plasma Caused by Periodic Magnetosound Perturbations with Discontinuities in a Quasi-Isentropic Magnetic Gas
Autorzy:
Perelomova, Anna
Powiązania:
https://bibliotekanauki.pl/articles/176914.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
non-linear magnetoacoustics
shock waves
adiabatical instability
acoustic activity
acoustic heating
Opis:
The magnetoacoustic heating of plasma by harmonic or periodic saw-tooth perturbations at a transducer is theoretically studied. The planar fast and slow magnetosound waves are considered. The wave vector may form an arbitrary angle θ with the equilibrium straight magnetic field. In view of variable θ and plasma-β, the description of magnetosound perturbations and appropriate magnetosound heating is fairly difficult. The scenario of heating depends not only on plasma-β and θ, but also on a balance between nonlinear attenuation at the shock front and inflow of energy into a system. Under some conditions, the average over the magnetosound period force of heating may tend to a positive or negative limit, tend to zero, or may remain constant when the distance from a transducer tends to infinity. Dynamics of temperature specifying heating differs in thermally stable and unstable cases and occurs unusually in the isentropically unstable flows.
Źródło:
Archives of Acoustics; 2020, 45, 2; 241-251
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Application of Selected Hierarchical Clustering Methods for Classification the Acoustic Emission Signals Generated by Partial Discharges
Autorzy:
Borucki, Sebastian
Łuczak, Jacek
Lorenc, Marcin
Powiązania:
https://bibliotekanauki.pl/articles/2097707.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
acoustic emission method
acoustic signals
partial discharges
power transformer
clustering method
Opis:
The paper presents the results of the application of the hierarchical clustering methods for the classification of the acoustic emission (AE) signals generated by eight basic forms of partial discharges (PD), which can occur in paper-oil insulation of power transformers. Based on the registered AE signals from the particular PD forms, using a frequency descriptor in the form of the power spectral density (PSD) of the signal, their representation in the form of the set of points on plane XY was created. Next, these sets were subjected to analysis using research algorithms consisting of selected clustering methods. Based on the suggested numeric performance indicators, the analysis of the degree of reproduction of the actual distribution of points showing the particular time waveforms of the AE signals from eight adopted PD forms (PD classes) in the obtained clusters was carried out. As a result of the analyses carried out, the clustering algorithms of the highest effectiveness in the identification of all eight PD classes, classified simultaneously, where indicated. Within the research carried out, an attempt to draw general conclusions as to the selection of the most effective hierarchical clustering method studied and the similarity function to be used for classification of the selected basic PD forms.
Źródło:
Archives of Acoustics; 2021, 46, 3; 409-417
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An acoustic sea glider for deep-sea noise profiling using an acoustic vector sensor
Autorzy:
Sun, Qindong
Zhou, Hongkun
Powiązania:
https://bibliotekanauki.pl/articles/32889290.pdf
Data publikacji:
2022
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
acoustic sea glider
acoustic vector sensor
ambient sea noise
target detection
Opis:
An acoustic sea glider has been developed for ambient sea noise measurement and target detection through the deployment of an acoustic vector sensor (AVS). The glider was designed with three cabins connected in sequence and it can dive to depths exceeding 1200m. The AVS fixed on the glider measure acoustic pressure and particle velocities related to undersea noise, and the inner attitude sensors can effectively eliminate the estimation deviation of the direction of arrival. The inherent self-noises of the acoustic sea glider and AVS are presented respectively in respect to the Knudsen spectra of sea noise. Sea trial results indicate that the AVS could work well for undersea noise measurement when the glider is smooth sliding, and the target azimuth estimated by AVS after correction is remarkably consistent with the values measured by the GPS, and direction-finding errors are less than 10 degrees. The research in this paper shows that the acoustic sea glider is able to undertake tasks such as a wide range of underwater acoustic measurement and detection.
Źródło:
Polish Maritime Research; 2022, 1; 57-62
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Global Index of Acoustic Assessment of Machines—Results of Experimental and Simulation Tests
Autorzy:
Pleban, D.
Powiązania:
https://bibliotekanauki.pl/articles/90747.pdf
Data publikacji:
2011
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
acoustic assessment
machinery
noise
Opis:
A global index of machines was developed to assess noise emitted by machines and to predict noise levels at workstations. The global index is a function of several partial indices: sound power index, index of distance between the workstation and the machine, radiation directivity index, impulse and impact noise index and noise spectrum index. Tests were carried out to determine values of the global index for engine-generator; the inversion method for determining sound power level was used. It required modelling each tested generator with one omnidirectional substitute source. The partial indices and the global index were simulated, too. The results of the tests confirmed the correctness of the simulations.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2011, 17, 3; 277-286
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of propagation of acoustic wave generated by a moving ship
Autorzy:
Gloza, I.
Domagalski, J.
Powiązania:
https://bibliotekanauki.pl/articles/331561.pdf
Data publikacji:
2003
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
acoustic wave
moving ship
Opis:
A moving ship is a source of acoustic perturbations resulting from her complex hull being a surface of irregular shape and from a rotational source - the propellers. The sources generate acoustic waves in wide frequency band. In case of a shallow sea the prapagation of the acoustic waves for varying source-detector distances and different frequencies are described applying the modes and ray theory.
Źródło:
Hydroacoustics; 2003, 6; 183-188
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ekran akustyczny w zabudowie miejskiej
Acustic screen in urban built-up areas
Autorzy:
Dziwisz, K.
Lebiedowska, B.
Powiązania:
https://bibliotekanauki.pl/articles/363068.pdf
Data publikacji:
2005
Wydawca:
Instytut Fizyki Budowli Katarzyna i Piotr Klemm
Tematy:
ekran akustyczny
acoustic screen
Opis:
Konieczność przestrzegania przepisów Komisji Europejskiej w zakresie hałasu wymaga nie tylko wykonania map hałasu dla dużych aglomeracji miejskich, lecz także przedstawienia programu działań technicznych dla poprawienia warunków akustycznych. Artykuł prezentuje możliwości zastosowania ekranów akustycznych w zabudowie miejskiej na przykładzie dwóch łódzkich skrzyżowań, dla których stwierdzono przekroczenie dopuszczaillych norm.
The European Commission noise regulations oblige various national stakeholders not only to map large urban agglomeritions but also to devise a programme of technical measures aimed at improving acoustic conditions in cities. This presentation discusses possible applications of acoustic screens in urban built-up areas. Two crossroads in the city of Łódź, central Poland, where permissible norm s are exceeded are analysed as case studies.
Źródło:
Fizyka Budowli w Teorii i Praktyce; 2005, T. 1; 55-65
1734-4891
Pojawia się w:
Fizyka Budowli w Teorii i Praktyce
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Acoustic Diagnostics Applications in the Study of Technical Condition of Combustion Engine
Autorzy:
Deptuła, A.
Kunderman, D.
Osiński, P.
Radziwanowska, U.
Włostowski, R.
Powiązania:
https://bibliotekanauki.pl/articles/176773.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
acoustic diagnostics
combustion engine
Opis:
The paper presents the possible applications of using acoustic diagnostics in inspecting the technical condition of an internal combustion engine with autoignition on the example of the Fiat drive unit with common rail system. As a result of measuring the sound pressure level for specific faults and comparing the noise generated by the motor running smoothly, the detailed maps of changes in the acoustic spectrum are possible to generate. These results may be helpful in the future diagnostics of internal combustion engines. In the paper, the results of scientific work in the area of research, design and operation of internal combustion engines, conducted at the Department of Automotive Engineering, in cooperation with the Laboratory of Hydraulic Drives & Vibroacoustics of Machines at the Wroclaw University of Technology are included.
Źródło:
Archives of Acoustics; 2016, 41, 2; 345-350
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Managing the acoustic climate in local government units – a new approach
Zarządzanie klimatem akustycznym w jednostkach samorządu terytorialnego – nowe podejście
Autorzy:
Paszkowski, W.
Powiązania:
https://bibliotekanauki.pl/articles/1205782.pdf
Data publikacji:
2013
Wydawca:
STE GROUP
Tematy:
acoustic climate
acoustic comfort
acoustic environment
soundscape
entropy
stimuli
klimat akustyczny
komfort akustyczny
środowisko akustyczne
entropia
bodźce
krajobraz dźwiękowy
Opis:
The paper presents a new approach to shaping acoustic comfort as a process of managing the acoustic environment in urbanised areas. The research in this area focuses on the psychoacoustic aspect of shaping acoustic comfort in an urban environment. This approach permits, depending on the purpose of land, not only to reduce the noise to the allowable limits but also to evaluate the acoustic quality of sounds originating in different sources. In this context, a review was performed of the research carried out on identifying soundscapes as a way of shaping acoustic comfort in the urban environment. In this paper it is suggested that the entropy method be used for the assessment of auditory sound perception. The research carried out by the author shows that linking the relationship between the quality of perceived sounds with the elements/factors which shape the acoustic environment can be used to valorise soundscapes.
W artykule przedstawiono nowe podejście do kształtowania komfortu akustycznego jako procesu zarządzania środowiskiem akustycznym na terenach zurbanizowanych. Rozwijane badania w tym obszarze opierają się na uwzględnieniu psychoakustycznego aspektu kształtowania komfortu akustycznego w środowisku miejskim. Skutkiem takiego podejścia, w zależności od przeznaczenia terenu, jest nie tylko redukcja hałasu do wartości dopuszczalnych, ale ocena jakości akustycznej dźwięków pochodzących z różnych źródeł. W tym kontekście przeprowadzony został przegląd podjętych badań nad identyfikacją krajobrazów dźwiękowych jako sposobu kształtowania komfortu akustycznego w środowisku miejskim. Zaproponowano w artykule wykorzystanie metody entropii dla potrzeb oszacowania percepcji słuchowej dźwięków. Z podjętych badań własnych wynika, że powiązanie relacji jakości postrzeganych dźwięków z elementami/czynnikami kształtującymi środowisko akustyczne może zostać wykorzystane do waloryzacji krajobrazów dźwiękowych.
Źródło:
Management Systems in Production Engineering; 2013, 1 (9); 19-25
2299-0461
Pojawia się w:
Management Systems in Production Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Die Welt der Töne und Geräusche. Über den Zusammenhang von Tonsignalen, der Konzeptualisierung und Versprachlichung von Emotionen. Eine Analyse am deutschen und polnischen Sprachmaterial aus semantisch-kognitiver Perspektive
The World of Tones and Sounds. On the Relation between Sound Signals, Conceptualization and, Making Emotions Lingual. An Analysis of German and Polish Language Material from the Semantic-Cognitive Perspective
Autorzy:
Kaczmarek, Hanna
Powiązania:
https://bibliotekanauki.pl/articles/458683.pdf
Data publikacji:
2020-06-20
Wydawca:
Uniwersytet Wrocławski. Oficyna Wydawnicza ATUT – Wrocławskie Wydawnictwo Oświatowe
Tematy:
emotion
conceptualization
acoustic signals
Opis:
Emotions as abstract phenomena are not easy to verbalize. On the lexical level, they are most frequently thematized or expressed through imagery. The article aims at elucidating a rarely discussed problem of making emotions lingual employing sound phrasemes. Sounds and noises of animate as well as inanimate nature are in the centre of the cognitive explorations. The sounds and noises are metaphorically mapped on the abstract, hard-to-reach target domain of emotions. The analyses will be conducted on German and Polish phrasemes.
Źródło:
Linguistische Treffen in Wrocław; 2020, 17; 129-139
2084-3062
2657-5647
Pojawia się w:
Linguistische Treffen in Wrocław
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Acoustics of Orthodox Churches in Poland
Autorzy:
Małecki, P.
Wiciak, J.
Nowak, D.
Powiązania:
https://bibliotekanauki.pl/articles/176358.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
orthodox churches
room acoustic
Opis:
An Orthodox church as a building expresses the Eastern Orthodox spirituality – all the details and general aspects have a deep and philosophical meaning. The architecture, being an illustration of the character of the Orthodox Church liturgy, has become a natural component of the cultural landscape of Poland and Eastern Europe. Acoustic research into Orthodox churches has so far been marginalized. Up to now, only a few churches of this type have been studied. The article is a review of the acoustic environment of churches in Poland. Churches, differing in terms of size, architectural style and other quantities, were chosen and acoustic measurements were made. The results of the measurements have been analyzed and collated. In particular, a detailed analysis and comparison was made for reverberation time as a function of frequency, due to the largest differences in this parameter between the rooms.
Źródło:
Archives of Acoustics; 2017, 42, 4; 579-590
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal lenses caused by any acoustic source
Autorzy:
Perelomova, A.
Powiązania:
https://bibliotekanauki.pl/articles/332019.pdf
Data publikacji:
2003
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
thermal lens
acoustic source
Opis:
The modern theory concerning to the heating cased by powerful sound source is presented. In contrast to the well-known approach allowing to calculate slowly varying heating due to periodic ultrasound, any acoustic sources may be treated. Subtle temporal structure of thermal lens forming may be traced. Formulae governing the forming of the thermal lens by arbitrary (including non-periodic) source are presented. The process is illustrated by some figures.
Źródło:
Hydroacoustics; 2003, 6; 171-176
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Acoustic streaming in focal and post focal region
Autorzy:
Grelowska, G.
Kozaczka, E.
Powiązania:
https://bibliotekanauki.pl/articles/332394.pdf
Data publikacji:
2003
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
acoustic streaming
focal area
Opis:
The paper presents concise theoretical description of mechanism of acoustic streaming in the field of finite amplitude wave. Special attention was concentrated on acoustic streaming in focal area into a beam produced by a bowl shaped source. A set up used in experimental investigation is also shown. The measurement was carried out at fixed conditions. Its result was compared to the result of calculation based on theory derived from the reasoning presented by W. Nyborg et al.
Źródło:
Hydroacoustics; 2003, 6; 125-130
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
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