2001 Fiscal Year Final Research Report Summary
The evaluaion of the complexity by the Fractal dimension of the environmental noise.
| Project/Area Number |
10680523
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
環境影響評価(含放射線生物学)
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| Research Institution | Shibaura Institute of Technology |
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Principal Investigator |
SHIBAYAMA Hideo Shibaura Institute of Technology, Professor, 工学部, 教授 (50052866)
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| Co-Investigator(Kenkyū-buntansha) |
FUKUDA Akiteru Shibaura Institute of Technology, lecturer, 工学部, 講師 (50052808)
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| Project Period (FY) |
1998 – 2001
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| Keywords | self-similar / affine transformation / Takens' Theory / iterated function system / fractal dimension / noise control / digital signal processing |
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| Research Abstract |
After advanced economic growth passed, we paid attention to society of taking harmony development from not only the side of the industry but also the point of the quality of the environment. Exceeding the range of prevention of pollution, we understood importance for the preservation of the natural environment and the earth environment. Environmental impact assessment law was carried out in June 1998 in Japan. In this law, equivalent noise level was adopted in place of median of the noise level used so far as an amount of foundation evaluation. But, it doesn't have a clause toward the quality of the environment noise. We know that there is unpleasant sound even if the level of the sound is low. Auditory experiments for psychological effects were done from a viewpoint of the complexity of a sound waveform. Fractal dimension was chosen as a measure of the complexity. A difference in fractal dimension can be recognized as a difference in the sound quality. The self-similar structure analysed by the fractal cording of environmental sound is shown. We consider analyzing self-similarity of time series signal that is transformed into IFS(Iterated Function System) to construct the affine map by the fractal coding. Three kinds of traffic noises that are generated by a bus, a car and a motorcycle were used as the environmental sound. The total sound information at the measuring point is contained in the environmental sound. The acoustic characteristics at the area can be known by analyzing the sound. And, the fractal transform is used for evaluation of the environmental sound structure. The fractal structure of the waveform is examined from the change in the parameters of IFS.
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Research Products
(12 results)
