Abstract
In order to develop a watching system for an aged single person by grasping his or her usage of electricity, we hatched out a method to infer whether a resident directly operated electric appliances or not from total load current of the household. Then we developed a prototype of the watching system and carried out a demonstration test for 11 actual aged single persons for 1 year in cooperation with a local government. The results of the test are showing the effectiveness of the system. We also have hatched out a method to automatically determine proper numerical values of parameters required for watching. It is absolutely necessary for the system to watch a great number of household simultaneously.
