An image forming apparatus includes an image carrier on which an electrostatic latent image is formed, a rotary developing device having N developer carriers on an rotation orbit and moving the N developer carriers to a development position opposite to the image carrier, and a toner concentration sensor that measures toner concentrations of the developers. The mobile station shifts a state mode to a permitted state mode when the state mode of the mobile station and the permitted state mode included in the broadcast information differ. The control unit controls the wake up signal to comprise a diffuse sound during a first part of the alert period and to comprise a localized sound during a subsequent part of the alert period. The methane is contained beneath and removed from an enclosing cover over the lagoon. The scans, together with geographic, temporal, and user-specific information, are obtained by the server that receives, processes, and records the message.