A stochastic evaluation for non-stationary random noise over a long time period based on local statinarity and its application to actual acoustics environment

A non-stationary environmental noise fluctuations can be treated as some composition of local state strips having arbitrary fluctuating pattern in a locally stationary time period. Its non-stationary characteristics can be seen in the form of its changing stage from a locally stationa...

Full description

Saved in:
Bibliographic Details
Main Authors: K. Nashimura, M. Ohta
Format: Article
Language:English
Published: Institute of Fundamental Technological Research Polish Academy of Sciences 2002-01-01
Series:Archives of Acoustics
Online Access:https://acoustics.ippt.pan.pl/index.php/aa/article/view/425
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A non-stationary environmental noise fluctuations can be treated as some composition of local state strips having arbitrary fluctuating pattern in a locally stationary time period. Its non-stationary characteristics can be seen in the form of its changing stage from a locally stationary state to another one by means of its temporal change of probability distribution. For a non-stationarity with continuously slow temporal change, the noise evaluation method is derived by considering the temporal change of moment statistics or distribution parameters. On the other hand, for a non-stationarity with stepwise rapid variation like an ON/OFF operation of machine, the noise evaluation method is derived by considering in principle the occurring probability of each of locally stationary state based on the mutually exclusive property. In the experimental consideration, the above contrastive two evaluation methods have been applied to actual cases with slowly changing environmental noise and rapidly changing machine noise.
ISSN:0137-5075
2300-262X