Abstract: Devices and techniques are generally described for automatic volume leveling of an audio signal. An audio signal may be received and a first portion of the audio signal may be stored in a buffer. A root mean square (RMS) estimate of a level of the first portion of the audio signal may be determined based at least in part on a second portion of the audio signal previous to the first portion. A modified audio signal may be generated by multiplying the first portion of the audio signal in the buffer by a variable gain. The variable gain may be based at least in part on the RMS estimate. The modified audio signal may be sent to a loudspeaker.

Abstract: Provided are an apparatus and a method for controlling the heating of the base within a chemical vapour deposition chamber, which apparatus is applicable to an MOCVD reaction chamber.

Abstract: A system capable of directing audio output to a portion of a shared acoustic environment. For example, the system may divide the environment into two or more sound zones and may generate audio output directed to one or more sound zones. The system may distinguish between target sound zones and quiet sound zones and may determine a set of global filter coefficients with which to direct the audio output. The system may generate a first set of filter coefficients that increase audio volume in the target sound zones and a second set of filter coefficients that increase a ratio of audio volume between the target sound zones and the quiet sound zones. The system may generate the set of global filter coefficients using a combination of the first set and the second set. The system may also direct audio from multiple audio sources in different directions.

Abstract: Provided are an apparatus and a method for controlling the heating of the base within a chemical vapour deposition chamber, which apparatus is applicable to an MOCVD reaction chamber.

Abstract: Provided are an apparatus and a method for controlling the heating of the base within a chemical vapour deposition chamber, which apparatus is applicable to an MOCVD reaction chamber.

Abstract: A method for MOCVD gas showerhead pretreatment, which includes: providing a reaction chamber, an evacuating system located at bottom of reaction chamber and a gas showerhead fixed on top of reaction chamber. The gas showerhead includes the cooling plate at the bottom and gas supplying system on the top; the processing steps include filling high-pressure pretreatment gas into reaction chamber-exhausting pretreatment gas-filling air-exhausting air and many other procedures; circulating above procedures until accomplishment of pretreatment on gas showerhead in the reaction chamber and other exposed components.

Abstract: Provided are an apparatus and a method for controlling the heating of the base within a chemical vapour deposition chamber, which apparatus is applicable to an MOCVD reaction chamber.