A bearing structure reduces friction between a roller and a bearing under a pressure. The assembly comprising an auxiliary magnetic field generating magnets arranged to be adjustably positionable relative to the stator to generate an auxiliary magnetic field to modify the primary magnetic field to thereby cause the armature member interacting with the modified magnetic field to operate at a targeted output characteristic. A user intervention policy is created to evaluate which data should be moved to a destination database. The slave clock may correlate received signals with a representation of the expected synchronization signal to produce a correlation sample sequence at a first sample rate which is related as n times the slave clock rate.