Abstract: The battery pack includes a cell stack and a battery case. The cell stack is formed by stacking a plurality of battery cells having a substantially rectangular parallelepiped shape. The battery case is formed in a substantially rectangular parallelepiped shape and accommodates the cell stack. The battery case includes a first protrusion protruding from an outer surface of the battery case to an outside of the battery case at a position of a gap between adjacent battery cells in a stacking direction of the cell stack.

Abstract: A result of statistical processing for a set of original data items can be obtained while the risk of leakage of information to be hidden is reduced by avoiding transferring and storing original data. Each of a plurality of data input devices comprises: means for acquiring an original data item to be hidden; and means for dividing the original data item in accordance with a secret ratio where adding up all the partial data items restores the original data item, and outputting a predetermined number of partial data items. Each of a predetermined number of arithmetic devices comprises means for performing a predetermined arithmetic operation based on a plurality of input data items, performs the arithmetic operation using partial data items as the input data items, each partial data item being outputted from each of a plurality of data input devices, and outputs the arithmetic result.