Due to rapid progress in medical and medi-care 
technologies, human life has lengthened for the past
decades. The population of elder people is thus
increasing globally. Most developed countries
including European countries and Japan are already so
called society of silver-hairs. Homecare and home
assistance of the elderly have become important issues
of future society. Many researchers have been working
on various assistant devices to allow the elderly still
have an independent living standard for their aging
life. Among many advanced healthcare technologies, a
remote activity monitoring system facilitate assistance
for safety warning and life-saving of the elderly