Statistical Analysis of the Equivalent Noise Level

2015 ◽  
Vol 39 (2) ◽  
pp. 195-198 ◽  
Author(s):  
Wojciech Batko ◽  
Bartosz Przysucha
Keyword(s):  
Statistical Analysis ◽  
Probability Density Function ◽  
Normal Distribution ◽  
Probability Density ◽  
Noise Level ◽  
Sound Level ◽  
Uncertainty Calculation ◽  
Measurement Results ◽  
Interval Value

Abstract The authors focus their attention on the analysis of the probability density function of the equivalent noise level, in the context of a determination of the uncertainty of the obtained results in regard to the control of environmental acoustic hazards. In so doing, they discuss problems of correctness in the applicability of the classical normal distribution for the estimation of the expected interval value of the equivalent sound level. The authors also provide a set of procedures with respect to its derivation, based upon an assumption of the determined distribution of the measurement results. The obtained results then create the plane for the correct uncertainty calculation of the results of the determined controlled environmental acoustic hazard coefficient.

scholarly journals Evaluation of Noise Level at the Position of Water Cutter Operator at Selected Enterprise

2019 ◽  
Vol 2 (2) ◽  
pp. 341-349
Author(s):  
Michał Pałęga ◽  
Marcin Kwapisz
Keyword(s):  
Work Environment ◽  
Noise Level ◽  
Noise Exposure ◽  
Sound Level ◽  
Exposure Level ◽  
Basic Information ◽  
Computer Service ◽  
Measurement Results ◽  
The Subject

Abstract The subject of this publication is to assess the exposure of the waterjet operator to the noise hazard. The publication presents basic information about noise in the work environment. Next, the procedure of noise measurement in the work environment was discussed and the results of tests carried out at the waterjet operator’s station for three basic activities were presented, ie: (1) plotter support, supervision of the cutting process, loading and receiving material, (2) auxiliary, transport and cleaning, (3) computer service, keeping documentation, hygienic and social break. The noise level test included the determination of: the maximum sound level A LA max, the peak sound level C LCpeak, the noise exposure level related to the 8-hour work day LEX,8h. Based on the obtained measurement results, it can be stated that the exposure to noise at the station of the waterjet operator is at an acceptable level.

scholarly journals Statistical analysis based on quaternion normal random variables

1985 ◽  
Vol 4 (3) ◽  
pp. 120-127 ◽  
Author(s):  
H. M. Rautenbach ◽  
J. J. J. Roux
Keyword(s):  
Statistical Analysis ◽  
Maximum Likelihood ◽  
Probability Density Function ◽  
Maximum Likelihood Estimation ◽  
Normal Distribution ◽  
Probability Density ◽  
Likelihood Estimation ◽  
Estimation Procedure ◽  
Unknown Parameters ◽  
Quaternion Case

The quaternion normal distribution is derived and a number of characteristics are highlighted. The maximum likelihood estimation procedure in the quaternion case is examined and the conclusion is reached that the estimation procedure is simplified if the unknown parameters of the associated real probability density function are estimated. The quaternion estimator is then obtained by regarding these estimators as the components of the quaternion estimator. By means of a example attention is given to a test criterium which can be used in the quaternion model.

Sound influence on spa park perception in feelings of visitors

2017 ◽  
Author(s):  
Małgorzata Sztubecka ◽  
Maria Mrówczyńska ◽  
Anna Bazan-Krzywoszańska ◽  
Marta Skiba
Keyword(s):  
Human Perception ◽  
Special Kind ◽  
Sound Level ◽  
Health Resort ◽  
Measurement Results ◽  
Noise Measurements ◽  
Permissible Levels ◽  
The One ◽  
The Impact

Noise can have many harmful effects on the recipients, however people exposed to noise on a long-term and regular basis can get used to it, even if the permissible levels are exceeded. In cities, green areas and park systems are provided to create a climate for rest and relaxation. Spa parks are a special kind of such park systems, which – in addition to the above-mentioned features – support therapies offered by spa facilities located there. On the one hand, patients and visitors appreciate various social and entertainment events held there, but – on the other – a multitude of sounds associated with them may reduce the comfort of their stay. The aim of this paper is to analyse the relationship between the results of noise measurements and the human perception of noise within the impact zone. The examined area is a spa park in the health resort district of Inowrocław, where seasonal measurements (taken in summer and winter) provided a basis for the determination of the connection between the measured values of equivalent sound level and the noise level perceived by surveyed people. A statistical analysis was performed to take into account the correlation between the obtained measurement results and the human perception of noise. It shows some differences in the perception of heard sounds. The results allow an evaluation of the soundscape of the analysed area.

A filter with a guaranteed asymptotic performance

1993 ◽  
Vol 441 (1911) ◽  
pp. 33-57
Keyword(s):  
Kalman Filter ◽  
Probability Density Function ◽  
Probability Density ◽  
Density Function ◽  
Extended Kalman Filter ◽  
Noise Level ◽  
Low Noise ◽  
The State ◽  
Optimal Probability ◽  
Expected Values

In the case of low noise levels the optimal probability density function summarizing the available information about the state of a system can be accurately approximated by the product of a gaussian function and a linear function. The approximation preserves the ability to estimate to an accuracy of O ( λ -2 ) the expected value of any twice continuously differentiable function defined on the state space. The parameter λ depends on the noise level. If the noise level in the system is low then λ is large. A new filtering method based on this approximation is described. The approximating function is updated recursively as the system evolves with time, and as new measurements of the system state are obtained. The updates preserve the ability to estimate the expected values of functions to an accuracy of O ( λ -2 ). The new filter does not store previous measurements or previous approximations to the optimal probability density function. The new filter is called the asymptotic filter, because the definition of the filter and the analysis of its properties are based on the theory of asymptotic expansion of integrals of Laplace type. An analysis of the state propagation equations shows that the asymptotic filter performs better than a particular widely used suboptimal approximation to the optimal filter, the extended Kalman filter. The extended Kalman filter does not, in general, preserve the ability to estimate expected values to an accuracy of O ( λ -2 ). The computational cost of the asymptotic filter is comparable to that of the iterated extended Kalman filter.

The Combined Closed Form-Perturbation Approach to the Analysis of Mistuned Bladed Disks

1993 ◽  
Vol 115 (4) ◽  
pp. 771-780 ◽  
Author(s):  
M. P. Mignolet ◽  
C.-C. Lin
Keyword(s):  
Probability Density Function ◽  
Probability Density ◽  
Density Function ◽  
Approximate Solutions ◽  
Forced Response ◽  
Perturbation Approach ◽  
Perturbation Techniques ◽  
Step Method ◽  
Bladed Disk

A two-step method is presented for the determination of reliable approximations of the probability density function of the forced response of a randomly mistuned bladed disk. Under the assumption of linearity, an integral representation of the probability density function of the blade amplitude is first derived. Then, deterministic perturbation techniques are employed to produce simple approximations of this function. The adequacy of the method is demonstrated by comparing several approximate solutions with simulation results.

Evaluation of Noise Characteristics of Drainage and Water Supply Systems in Apartment Bathrooms

2014 ◽  
Vol 1025-1026 ◽  
pp. 987-990
Author(s):  
Jun Oh Yeon ◽  
Kyoung Woo Kim ◽  
Kwan Seop Yang ◽  
Byung Kwon Lee
Keyword(s):  
Water Supply ◽  
Noise Level ◽  
Drainage System ◽  
Low Noise ◽  
Sound Level ◽  
Water Supply Systems ◽  
Apartment Building ◽  
Noise Characteristics ◽  
Measurement Results ◽  
Supply Systems

We have developed a low-noise drainage system, which was installed in bathrooms of apartment building units as well as in a mock-up test building, to evaluate the noise level in order to reduce the noise produced in the bathrooms of multiunit dwellings. The drainage system installed in the mock-up building consists of six types of detachable drains, and the level of noise produced during toilet use in the upper unit was measured in the lower unit. The measurement results showed that low-noise drainage 4 exhibited the Leq(equivalent continuous sound level) at 34.7 dB(A). The noise measurement results of various types of low-noise drains installed in an apartment building showed that the Leqduring toilet use was 46.7 dB(A) on average, and the Leqduring sink use was 40.5 dB(A) on average.

scholarly journals Perbaikan Tingkat Kebisingan pada Ruang Produksi Yessy’s Collection dengan Pendekatan Ergonomi

2017 ◽  
Vol 16 (2) ◽  
Author(s):  
Afgan Suffan Aviv ◽  
Bambang Suhardi ◽  
Pringgo Widyo Laksono
Keyword(s):  
Work Environment ◽  
Noise Level ◽  
Threshold Value ◽  
Sound Level ◽  
Physical Work ◽  
Level Measurement ◽  
Measurement Results ◽  
Physical Work Environment ◽  
Level Meter ◽  
Physical Environmental Factors

<p><em>Implementation of ergonomics is generally a design or redesign. One of them may include the design of the physical work environment. Ergonomic work environment conditions are provide comfort and security for workers. Physical environmental factors that can affect the comfort and safety of noise level.  A good physical work environment will increase work capability or labor productivity. In a work environment, workload assessment can also be carried out to measure worker conformity and comfort. Workload assessment is carried out simultaneously with measurement of noise level . </em></p><p><em>Whose problematic noise, the industry is located in Tawangsari RT 03 RW 34 Mojosongo, Jebres, Surakarta named Yessy's Collection. Measurement of noise level to improve worker comfort, so that productivity increases. The methode used is measurement using 4 in 1 Environment on sound level meter function illustrated with Software Surfer 11.</em></p><em> The noise level measurement results are below the specified threshold value except at 1 coordinate in swabing station (stasiun penyesekan),that is  at above threshold value. To proposed improvements as noise control is engineering control, administrative control and use of PPE</em>

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