Currently, human-behavior monitoring systems
can be divided into two types. The first type of activity
monitoring system consists of multiple sensors
installed in a room for monitoring the body activities.
Ogawa et al. [1] developed a remote monitoring
system for elderly patients in their domestic house.
Several sensors were installed, including infrared
sensors to detect human movement, magnetic switches
to detect the opening and closing of doors, wattmeters
embedded in wall sockets to detect the use of
household appliances, and a CO2 sensor to detect the
presence of a subject in a room. Noguchi et al. [2] also
developed a system for detecting human behaviors in
a room by several types of sensors embedded in the
room.