Virtual damper position data, simulatively representing a position of a damper member provided for suppressing vibration of a string in a physical tone generating mechanism of the acoustic piano, is generated on the basis of key-on data, key-off data, released key position data, damper pedal position data, sostenute pedal-on data and sostenute pedal-off data. A user, for example, the user experiencing the highest interference, is selected from a plurality of users using the radio access cell. A wafer transfer arm may be located near the wafer cassette. As the piston moves further, sealing structure seals gas coming through the aperture thereby isolating the compressed air in the outer chamber from the inner chamber. That section is functionally connected to the said switching element or circuit system in such fashion that applying pressure on the housing or bending or deforming the elastic section triggers a switching operation of the switching element or circuit system. The apparatus may further includes a base station that allows the equipment to operate while the base station receives the authorization signal from the biometric scanner, and which prevents the equipment from operating shoortly after the authorization signal is no longer received from the biometric scanner.