Embodiments of the present disclosure provide a calculating apparatus and method for nonlinear weighting coefficient. A hard-disk drive includes one or more electronic components configured to divide a track, of a plurality of concentric tracks on a magnetic-recording disk, into a plurality of portions, and write data to each of the plurality of portions at a recording density that is independent of the recording density used for any of the other portions. First and second traces are included on the top and bottom surfaces. and second implanting said SOI layer to achieve predetermined dopant concentrations in a polycrystalline semiconductor gate conductor and in source and drain regions disposed adjacent to the poly gate, wherein a maximum depth of the first implanting is greater than a maximum depth of the second implanting.