A transmission direction switching device for a half-duplex communication apparatus includes a data transmission detector connected to a universal asynchronous receiver transmitter via a sending line and a direction-switching rule executor connected to a half-duplex communication interface driver having a signal subtraction function via a direction control line. By reading the GUI window, the user can know what the recognizable grammar and vocabulary are for spoken input at any moment in the dialog. The actuator includes a piston moveably disposed in a casing, and a piston rod assembly that is connected to the other one of the vibrating component or the support structure. 0Heat stability: not more than about 50\xb0 C. The process according to the present invention comprises the following procedural steps: green glass is manufactured; the green glass is placed in a suspended state on a levitation substrate by supply of levitation gas; the green glass is heated in the suspended state by IR radiation until such time as the desired ceramising has set in.