A semiconductor memory device includes a supporting substrate including semiconductor materials. At least one of the plurality of nodes receives sensor data from a sensor. In order to solve the above problems, the present invention provides an improved electric motor comprising an armature having a core formed by a magnetic material and having a coil wound around the core; and a secondary disposed within the armature with a clearance formed therebetween and supported to be relatively movable with respect to the armature. Part or the entirety of the renewable hearth which was degraded during operation is renewed, and the hearth material for forming a new renewable hearth is fed.