A USB electric fragrant emitting joint comprises an upper casing having emitting holes and USB pattern; a lower casing having a groove at a bottom thereof; a USB connecting terminal being placed in a front end of the upper casing and lower casing; a fragrant rod; an electric heating element. Array configuration allows accurate and repeatable configurations suited to studio and field use. Responsive to the number of same matches exceeding a predetermined threshold, the commercial detection system determines that the media stream has commercial content. A gate electrode fills up the trench having the gate insulation layer formed therein. Related systems, apparatus, and methods are also described.