A sliding door repair apparatus to facilitate horizontal sliding movement of a preinstalled sliding door having one or more defectively sliding wheel being supported on a lower track. A method for receiving data in a wireless communication system according to one aspect of the present invention is configured such that a base station receives, from a mobile station, a signal including information and data on the transmission mode which the mobile station has selected in accordance with a channel status, and decodes the data in accordance with the transmission mode. If the device user is identified as a customer engineer, the system control part displays operations not permitted to be performed by the customer engineer in a manner different from permitted operations on an operations display part. Rather, it records the addressnode ID andor other information in order to identify its neighbor, and uses an alternative mechanism to either record the adjacency separately in order to populate or verify its topology database) or communicate an out-of-band control message to the neighbor. The laser beam machining method irradiates laser light while positioning a focus point at the inside of a machining target to thereby form a treated area based on multiphoton absorption along a planned cutting line of the machining target inside the machining target and also form a minute cavity at a predetermined position corresponding to the treated area in the machining target. Based on the seat conditions, the control module generates one or more control signals to compensate, enable, disable, or otherwise modify the safety system.