| Project/Area Number |
15K05857
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Dynamics/Control
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| Research Institution | The University of Electro-Communications |
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Principal Investigator |
Kamakura Tomoo 電気通信大学, 産学官連携センター, 客員教授 (50109279)
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| Project Period (FY) |
2015-04-01 – 2018-03-31
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| Project Status |
Completed (Fiscal Year 2017)
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| Budget Amount *help |
¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000)
Fiscal Year 2017: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2016: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
Fiscal Year 2015: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
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| Keywords | 超音波 / 非線形音響 / パラメトリックスピーカ / ハイレゾリューション / パラメトリックアレイ / 自己復調 / ハイレゾルーション音源 / 超指向性スピーカ / 非線形性 / 大音響化 / 飽和現象 / 自己復調現象 / 歪み低減 |
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| Outline of Final Research Achievements |
This study introduces theoretical and experimental attempts for the improvement of conversion efficiency from electric to acoustic power in driving parametric loudspeakers. In line with the fact that parametric sound pressure is generally increased by decreasing primary frequencies, a 25-kHz ultrasonic emitter is fabricated in order to realize a long distance acoustic alert system. Incidentally, audio signals pass through three processes when parametric loudspeaker is driven. These are the amplitude-modulation process, emitting process of ultrasound waves, and self-demodulation process. To find clues to improve the features of parametric loudspeaker, the study demonstrates that the above three processes are mathematically modeled and are successfully connected via computer simulation of using high resolution source signals with 96 kHz sampling frequency and 16-bit quantization.
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