A disk array controller is made up of multiple disk array control units for implementing the data readwrite operation and each having channel IF units, disk IF units, cache memory units and shared memory units. The ferroelectric body can be formed by chemical-mechanical polishing of a ferroelectric film. The rounded portions are located proximate to important structural support areas of an intended wearer’s foot on either or both sides of the shoe sole or the middle portion of the shoe sole, or at various combinations of these locations.