The semiconductor device includes an active region, a stepped recess channel region including vertical channel structures, a gate insulating film, and a gate structure. The product exits the coiler at a reduced velocity and is delivered to and progressively accumulated on a cylindrical drum as a helical formation of rings. A modified Maximum Flow Algorithm that satisfies the network constraints is applied to the Network Flow Problem to generate a solution to said constrained pin-to-probe assignment problem. The selected estimated reciprocal term and the selected reciprocal error term correspond to at least a portion of a divisor.