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1
Content available remote

Numerical Errors - Numerical Uncertainty - in the Identification and Estimation of Vibroacoustic Processes

100%
Batko W.
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issue 1
7-10
EN
Problems of numerical errors in the identification and estimation procedures of vibroacoustic phenomena are discussed in the hereby paper. The main attention is focussed on problems of errors generated by different algebras governing experimentally recognisable vibroacoustic effects and the algebra applied in the utilisation of procedures of their processing. Assessment of errors for elementary operations: adding, subtracting, multiplying and raising to a power - is derived. The problem of their presence in the current model solutions as well as in the implications for processes: cognitive, experimental (testing conditions) and their implementation is discussed. The postulate of the necessity of supplementing assessments of the measurement uncertainty in vibroacoustic examinations with assessments of the numerical uncertainty - are formulated. Various ways of looking for solving this problem are outlined. References to Author's and co-authors' own investigations - in this field - are also done.
2
Content available remote

Modifications of Computational Formulae of Decibel Algebra Applied in Acoustics

100%
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.
3
Content available remote

Uncertainty Evaluation in Modelling of Acoustic Phenomena with Uncertain Parameters Using Interval Arithmetic

64%
Batko W., Pawlik P.
Acta Physica Polonica A
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2012
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vol. 121
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issue 1A
A-152-A-155
EN
Uncertainty assessment in modelling of acoustic phenomena with uncertain parameters using interval arithmetic on the example of the reverberation time estimation, are presented in the paper. The application of the classical interval analysis formalism as well as its expansions are shown. Statistical methods of estimation of the reverberation time are based on parameters, which are related, among others, to the geometry of the analysed room, characteristics of sound absorption, and interior transmission. Values of these parameters are usually difficult to determine, which has a significant influence on the modelling result. The interval analysis allows to determine the variability interval of the parameter being estimated. The authors determined the influence of the input parameters uncertainty on the estimated reverberation time, calculated according to the Sabine, Eyring-Norris and Millington-Sette formulae. The uncertainty analysis was performed for the literature data, related to the reverberation time calculations of the room of a certified acoustics.
4
Content available remote

Uncertainty Assessment of Index M

64%
Batko W., Przysucha B.
Acta Physica Polonica A
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2012
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vol. 121
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issue 1A
A-156-A-159
EN
Administrative decisions, related to the selection of the priority of activities minimising acoustic effects in the analysed areas, are determined by the index M values. This index is also known as the noise protection agents demand. A form of its function is determined by variables describing the number of residents and the level of exceeding the permissible noise in these inhabited regions. Uncertainty of decisions resulting from such assessments is conditioned by numerical measures: inaccurate measurements of exceeding permissible noise indicators as well as errors in the estimation of the number of residents exposed to them, formulated in probabilistic categories and interpreted in an interval way. Thus, the uncertainty assessment of index M, being the function determined by means of those variables, requires the determination of the density of probability distribution function of its occurrence. The method of its determination constitutes the contents of the presented hereby paper. The study concentrates on the derivation of the density of probability distribution function of index M, at the assumption that the distribution of variable errors is in a form of the normal cut distribution. The computational algorithm, allowing to perform necessary numerical calculations assigned to the uncertainty assessment process of index M, is presented. The obtained results are illustrated by the example.
5
Content available remote

Random Distribution of Long-Term Indicators of Variable Emission Conditions

64%
Batko W., Przysucha B.
Acta Physica Polonica A
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2011
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vol. 119
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issue 6A
1086-1090
EN
This study is dedicated to the problem of estimating uncertainties of long-term noise indicators, when differences in the sound level emission at various time periods of the calendar year are taken into consideration. This task is defined by referring their influence values - in the determined time intervals - to the year period. Due to the limited possibilities of a total monitoring of parameters necessary for the precise estimation of the long-term sound levels, this estimation process is often limited (in accordance with the EU environmental recommendations) to two condition classes. They are defined by two sound levels occurring with probabilities (frequencies) p and 1-p, in the analyzed reference period. In this paper we present a method of calculating uncertainties of this procedure assuming that frequency of determined events are known. The probability distribution for the estimated value was assessed. The developed model formalism of the estimation of uncertainties of long-term sound levels together with algorithms assigned to it, was analyzed. The proposed solution was illustrated by examples of uncertainty calculations of the averaged sound levels in acoustic assessments of environmental hazards.
6
Content available remote

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

64%
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.
7
Content available remote

Robust Statistical Procedures in Statistical Analysis of Controllable Noise Indicators

64%
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.
8
Content available remote

New Method of Uncertainty Evaluation of the Sound Insulation of Partitions

64%
Batko W., Pawlik P.
Acta Physica Polonica A
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2013
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vol. 123
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issue 6
1012-1015
EN
The analysis of uncertainty related to evaluation of sound insulation of partitions performed according to standard solutions recommended in The Guide to the Expression of Uncertainty in Measurement (GUM) by ISO/IEC-1998 and according to the new method based on the interval analysis - is presented in the paper. Both methods are compared and their application advantages presented. Limitations of the current solutions based on the law of propagation of uncertainty are shown. The method of the estimate derivation for the sound insulation based on interval arithmetic related to the measurement data is presented. The influence of the input parameters uncertainty on the calculation results of the sound insulation of partitions is determined. The considerations are illustrated by numerical examples.
9
Content available remote

The Spectral Response of Hand-Arm System

64%
Barański R., Batko W.
Acta Physica Polonica A
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2011
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vol. 119
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issue 6A
913-915
EN
Recently we have used better solution to protect hand tool operators. In spite of our good intentions there is still endanger on high level vibration. For that reason we need to improve protection constantly. One of the most important properties of hand-arm system is knowledge about spectral response. In this article we try to obtain spectral response in narrow band-pass filters in accordance with IEC 1260:1995 and ANSI S1.11-2004 standards (implemented in LabVIEW software). To measure signals we used accelerometer placed on a wrist and on a tool. Of course the vibrations are attenuated by hand (cartilage, muscular tissue) but the question was what the shape of envelope in measurement range is. Our research used measurement on two different systems. The one was based on vibration inductor (laboratory environment), the second one used drill (real environment). This research is a part of a wider project to make virtual model of hand-arm system.
10
Content available remote

Application of the Bayesian Inference for Estimation of the Long-Term Noise Indicators and Their Uncertainty

64%
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.
11
Content available remote

Model of the Gears Based on Multibody System and Its Validation by Application of Non-Contact Methods

51%
Dąbrowski D., Batko W., Cioch W., Plascencia-Mora H.
Acta Physica Polonica A
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2013
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vol. 123
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issue 6
1016-1019
EN
In the paper an application of laser measurements for validation of the gears dynamic model have been presented. The model of the gears was compared with an experimental data in case of diagnostics of manufacturing failures. The comparison was done on the basis of vibration signals generated by the model and the real object. In the experiment correct work as well as incorrect one of the gears was studied. Purpose of the paper is to compare the model with the experimental data; to this end, the Multibody model of the gears was build in MSC ADMS software. The model consists of two gears and two shafts, with both gears and shafts treated as rigid bodies, but contact surfaces between them are flexible. To conclude, in the study comparison of acceleration signals estimates behavior due to other gears faults in the experiment and in the model has been presented. For optimal model validation, laser measurements on the shaft in the experiment were conducted.
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