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[jmrplens]

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[mwp4444]

I am a Ph.D. student in mechanical engineering. We are going to measure noise reduction based on aerogel developed by us during nanocomposite material research. I feel a lot of gratitude for A-Lab. Thanks to this, it seems that noise reduction research can be conducted. I have an inquiry during the measurement.

Based on the impedance tube, sound absorption was measured, and the measured value was negative. The sample file you attached also has a negative number.
It is known that a value between 0 and 1 should be obtained for the sound options coefficient value. (Refer to the paper)
Matlab determines that modification is necessary mathematically, and I am also looking at the code from the beginning.
Please tell me if I'm going in the wrong direction.
Measurement_of_the_Acoustic_Absorption_Coefficient.pdf