Abstract: According to one embodiment, a semiconductor storage device includes a plurality of electrode films on a substrate, spaced from one another in a first direction. A charge storage film is provided on a side face the electrode films via a first insulating film. A semiconductor film is provided on a side face of the charge storage film via a second insulating film. The charge storage film includes a plurality of insulator regions contacting the first insulating film, a plurality of semiconductor or conductor regions provided between the insulator regions and another insulator region.

Abstract: A defrosting control unit for providing centralized control of the defrosting a showcase having showcase units with defrosting devices includes an environmental informer ion signal generation portion and a defrosting control portion. The signal generation portion generates a signal reflecting at least one environmental parameter such as whether it is daytime or nighttime, the difference in air temperature measured at different places in a showcase unit, the deviation of the temperature difference with respect to a steady-state value, and the temporal variation of the deviation. The defrosting control portion receives the environmental information signal from the signal generation portion and sends a defrosting start signal and a defrosting end signal to the defrosting devices at a time interval . The signal generation portion may include a fuzzy reasoning portion, membership functions, and rules so that an inference on the optimal time for starting a defrosting operation can be made.