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Application of the Bootstrap Estimator for Uncertainty Analysis of the Long-Term Noise Indicators

100%
Batko W., Stępień B.
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issue 1
11-16
EN
In the process of environmental noise hazards assessment besides estimation of uncertainty measurement of control results there should be made errors analysis related to estimation processes to long-term noise indicators. the condition of correct quantification of uncertainty budget components in the control process is using proper analysis method. The problem rest on determining density function of probability distribution of long-term noise indicators. in order to several conditioning characteristic for the problem it can not be to solved by classic estimation analysis applied in statistical researches, without different reservations. There was formulated the estimation idea of seeking density function of long-term noise indicators distribution by bootstrap method, which does not generate limitations for form and properties of analyzed statistics. There was presented theoretical basis of the proposed method, and the example of calculation process which make possible determining searching estimators of expected value and variance of long-term noise indicators L_{DEN} and L_{N}. The illustration for indicated solutions and usefulness analysis was continuous monitoring results of a traffic noise recorded on one of the main arteries of Kraków.
2
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Application of the Bayesian Inference for Estimation of the Long-Term Noise Indicators and Their Uncertainty

100%
Batko W., Stępień B.
Acta Physica Polonica A
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2011
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vol. 119
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issue 6A
916-920
EN
The problem of estimation of the environmental noise hazard indicators and their uncertainty is presented in the hereby paper. The main attention is focused on the estimation process of the long-term noise indicators and their type A standard uncertainty defined by the standard deviation of the mean of the measurement results. The rules given in the ISO/IEC Guide 98 are used in the calculations. It is usually determined by means of the classic variance estimators, at the assumption of the normality of measurements results. However, such assumption in relation to the acoustic measurements is rather questionable. This is the reason that the authors indicated the necessity of implementation of non-classic statistic solutions. There was formulated the estimation idea of seeking density function of long-term noise indicators distribution by the Bayesian inference, which does not generate limitations for form and properties of analyzed statistics. There was presented theoretical basis of the proposed method, and the example of calculation process which make possible determining searched estimators of expected value and variance of long-term noise indicators L_{DEN} and L_{N}. The illustration for indicated solutions and usefulness analysis was constant monitoring results of traffic noise recorded on one of the main arteries of Kraków, Poland.
3
Content available remote

Shipping Low Frequency Noise and Its Propagation in Shallow Water

80%
Kozaczka E., Grelowska G.
Acta Physica Polonica A
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2011
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vol. 119
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issue 6A
1009-1012
EN
One 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. The modes constitute wave packet propagating with group speed in the direction parallel to the sea surface. The paper presents results of the experimental investigation concerning the distribution of the sound field created by moving ship in the shallow water, in a small distance from the ship. The main acoustical characteristics, describing features of the field are spectrograms in pseudo-3D system: distance and frequency in geometrical form, and sound intensity in the optical one (color). Results presented in such a way pointed individual features of the sound source known often as acoustical signature of the source (ship).
4
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Sound Pressure Level Analysis of Commercials and Regular Programs

80%
Malecki P., Wiciak J.
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issue 1
118-122
EN
Popularity of television and multitude of commercials during the TV broadcast lead to the analysis of its sound levels. Costs of commercials' time cause producers to make commercials much louder than a regular TV program. The article shows results of commercials and regular program sound level (RMS and FFT) analysis and the difference in sound levels of commercials compared to a regular program. The analysis also shows the difference between public and private TV. The authors of the article suggest a solution to this problem and its effects.
5
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Robust Statistical Procedures in Statistical Analysis of Controllable Noise Indicators

80%
Batko W., Knapik O.
Acta Physica Polonica A
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2013
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vol. 123
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issue 6
1007-1011
EN
The subject of the paper is statistical analysis of noise measurement results in control research of environment which is crucial for the process of identification, estimation, and interpretation of the characteristics of representative noise indicators. The proposed approach is based on robust methods of statistical analysis. In particular, the method of modeling measurement results with the use of autoregressive-moving average (ARMA) time series models is described. The subjects of identification, analysis, and connected matter of verification that occur during proposed mathematical formalization of considered problem are stated. Furthermore, the question of the validity and usability of normal distribution approximation, which is very common in modeling and estimation of the expected value of the equivalent sound level, is addressed. The illustration of the proposed methodology is represented by an example of the noise analysis from the permanent monitoring in the city of Kielce. The obtained results create the background for uncertainty of estimates of calculation concerning controlled noise indicators that describe the state of acoustic environmental threats.
6
Content available remote

Modifications of Computational Formulae of Decibel Algebra Applied in Acoustics

80%
Batko W.
Acta Physica Polonica A
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2011
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vol. 119
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issue 6A
909-912
EN
The analysis of description rules of acoustic effects in decibel algebra was performed in the presented paper. The attention was drawn to the incompatibility between mappings examined on the decibel values set and axioms of the real numbers theory. The consequences of this fact as well as the needs of the necessary modifications of relations describing a cooperation of sound levels from various sources (expressed by adding, subtracting or multiplying) were discussed. The necessary corrections were proposed. The analysis of differences was performed in relation to generally applied rules of processing the decibel measurement results in acoustic examinations.
7
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Quietness in the Soundscape of the Białowieża National Park

70%
Wiciak J., Mleczko D., Ozga A., Wszołek G., Wierzbicki J., Piechowicz J., Małecki P.
Acta Physica Polonica A
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2015
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vol. 128
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issue 1A
A-79-A-84
EN
The quietness, defined as the near or complete absence of sound, in the context of the natural environment protection, may be considered a state in which no undesired of foreign sounds occur, and, by analogy to noise, analyzed in two aspects: that pertaining to measurements and the subjective one. The article discusses the lowest levels of sounds recorded at night in the soundscape of the Białowieża Forest. Due to low levels of the examined sounds and the technical problems that occurred while the sounds were being measured and registered, the acoustic examination of the measurement set-up in an anechoic chamber has also been presented. The research is aimed at defining precisely the concept of quietness prevailing in the nature in the subjective aspect by determining both the range of levels and the characteristics of preferred sounds.
8
Content available remote

Studies on Infrasound Noise Generated by Operation οf Low-Power Wind Turbine

61%
Pierzga R., Boczar T., Wotzka D., Zmarzły D.
Acta Physica Polonica A
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2013
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vol. 124
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issue 3
542-545
EN
Subject matter of this paper deals with issues of the environmental impact of infrasound noise associated with operation of low-power wind turbines. It is now the current and relevant problem for both the cognitive and utilitarian standpoint. There is now a considerable growth in the number of such installations in Poland, Europe and in the world, due to the possibility of locating them on existing building roofs in heavily urbanized areas, and without having to build additional supporting structures. As part of the study, measurements of low frequency acoustic signals generated during operation of micro turbine equipped with a rotor of vertical axis of rotation relative to the wind direction have been performed. Analyses were carried out in order to determine the impact of wind speed and selected meteorological parameters on the level of infrasound signals emitted by the test turbine. In addition, frequency analysis of the recorded signals was performed. Then, the obtained results were subjected to comparative analysis. In summary, the achieved results were referred to the limits of sound pressure intensity level of infrasound signals as specified for the working environment in accordance with the Polish Standard PN-Z-01338.
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