A lockable media storage box includes a base and a lid connected to the base with at least one hinge. In one embodiment, the system includes: a check code generator that transforms the interface of the dynamically linkable component into an interface identifier representing the interface and couples the interface identifier to the dynamically linkable component and a interface verifier that employs the interface identifier to determine a compatibility of the dynamically linkable component. If an input signal level of the orthogonal modulator within the transmitter circuit lowers, this variable attenuator circuit is operated so as to lower the bias of the orthogonal modulator to reduce the amount of occurrence of carrier leak, and to prevent the signal during low output level and carrier leak ratio from being deteriorated. An analysis is performed over the computer program file to find out possible values of the parameters of the calls. And the amplitude of the charge potential detected by the detecting unit is monitored by a data processing unit, thereby making it possible to accurately identify not only the state of the road surface but also an internal pressure state of the tire, a wear state of the tire, and the like during vehicular travel.