The invention provides a data output system which can control a printer in accordance with the position of a user without providing a mobile terminal and the printer with special devices, which can reduce the processing load on the mobile terminal, which can ensure the convenience of the user when using the printer, and which avoids inconvenience as a result of incorrect settings by the user. In preferred embodiments, concentrated solar radiation is received and converted to heat at varying depths in the receiver such that multiple layers of surface are used to heat the working fluid. The locking linkage preferably includes two locking members arranged to make locking engagement with the base of the claims at locations rearward of the locations where the chair’s rocker cams are supported. The net loop gain is between zero and one. If the user is a key contact for the operation or is otherwise required or allowed to be associated with a role in the operation, the user also associates with a role from the list of roles in the role-specific directory instance.