A see-through-the-wall imaging system uses a plurality of geographically separated positioning transmitters to transmit non-interfering positioning signals. In one embodiment, a starting model of seismic velocity is assumed. The pinch housing in its transition region from the web wall to that sidewall which is distant from the annular notch of the pinch roller is provided with an inner, elongate side guide surface for the flexible tubing. Simultaneously pivoting the cams forcibly moves the sliding window pane between a closed position wherein the sliding window pane is in a first plane substantially flush with an outer surface of the fixed window panes and an open position wherein the outside surface of the sliding window pane is in a second plane substantially parallel to and offset from the first plane. The gas sensor can be widely applied for monitoring the safety of a working environment, securing the safety of workers, alerting potential hazard in a factory, inspecting harmful materials in a specific area, testing leakage of a pipeline, inspecting waste gas exhausted from automobilemotorcycle, and monitoring the living quality of household environment. The method according to an embodiment includes monitoring a usage of at least one resource, and performing a memory arrangement in the mobile terminal when the usage of the monitored at least one resource falls within pre-set conditions for performing the memory arrangement.