Automatic control of the power of the transmitters of a near-end-far-end transceiver pair is achieved by first determining whether the strength of the signals received at near-end and far-end receivers of the near-end-far-end transceiver pair are simultaneously attenuated a prescribed value below received signal strength values measured during clear weather free-space conditions. The transducer elements are carried on a flexible support that allows the transducer elements to be configured to an examination subject. Other embodiments have been claimed and described. The second set of variables is a partition suitable for use in determining an overapproximation of the reachable states of the selected variable.