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The defense date of the thesis is 2005-07-20
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URN etd-0720105-082440 Statistics This thesis had been viewed 1949 times. Download 19 times. Author Yu-ting Lin Author's Email Address email@example.com Department Mechanical Engineering Year 2004 Semester 2 Degree Master Type of Document Master's Thesis Language English Page Count 110 Title Noise Source Identification and Noise Reduction of High Speed CD-ROMs Keyword Taguchi method Noise Source Identification CD-ROM CD-ROM Noise Source Identification Taguchi method Abstract This article is meant to discuss the CD-ROM noise when it is loaded with a disk with 2 noise sources. The first is the noise through flowing and this is exactly the sound pressure value assigned by the CD-ROM makers. The pneumatic noise passing to the ears of users is referred to as aerodynamic noise. This value can be measured under the rotation of CD-ROM. The second one is the noise caused by vibration when the CD-ROM is reading or searching the data. This vibration energy will be directly passed to the chassis shell of PC set and make the chassis become the noise amplifier. How to recognize the source of the sound pressure of the CD-ROM and using Taguchi method and grey relational theory find out the optimum parameter combination will the issues within this research.
In this research, it is confirmed that there are two sources of the sound pressure of the CD-ROM under the high rotational speed. On the 700Hz, the sound pressure is caused by the airflow going though front and back interstices of laser disc machine. On the 1700Hz, the sound pressure is caused by the airflow knocking the internal part of the shell of the laser disc machine. So the noise on 700Hz and 1700Hz belong to the aerodynamic noise. Besides, no matter what Taguchi method and grey relational theory, the optimum parameter combination which is used perforated plate of reducing the total sound pressure can reduce 5.1 dB. And the optimum parameter combination which the distances are changed between the disc and the shell around the laser disc machine of reducing the total sound pressure can reduce 4.8 dB.
Advisor Committee Chao-ming Wang - advisor
Ying-chun Chang - advisor
Yau-sheng Chang - co-chair
Files Date of Defense 2005-07-07 Date of Submission 2005-07-20