The present invention can print out operating instructions, HELP documents, the latest image forming apparatus information, support and maintenance information, advertisements about new models and services, and the like without incrementing a charging counter. Waste material is injected into a reactor vessel having thermophilic microorganisms to form a volume of bulk liquid in the reactor vessel. To prevent limited access users from gaining access to the intranet by changing addresses, the system continuously performs periodic checks for address changes. As such, forces are directly transferred through the tether to the anchor strap and, ultimately, to the anchor in order to resist forward movement and downward rotation of the driver’s head. Thereafter, the difference between the imported and the corresponding predicted signal-strength is calculated for each measuring point, and a value indicating the correctness of the stored parameters is estimated, based on said calculated signal-strength differences.