SHMUC Use Case class B
Anomaly in Time Of Occurrence

SHMUC prototype  >  B_Time_Of_Occurrence_Use_Cases

The start time is a meaningful factor in smart home monitoring: an inappropriate activity start time could imply illness or even dementia. It is possible that a forgetful person can be reminded of activities that should have taken place.

B1 Variation in Shower Start Time

B2 Taking Medicine After Midnight

B3 Late for Church

B4 The Missed Visit

Discussion

As with the abnormal duration, the abnormal start times presented in the three preceding use cases seem easy to detect. However, there are context and other issues that affect things:

i) While some people have regular schedules and fixed activity start times, others are more variable in their timings. There are also some behaviours that, even amongst the most regular people, move from their normal times due to some sudden reasons such as in use case B2. For this problem, it may be that behaviours will need to be categorised into regular and irregular ones. However, the problem in use case B2 is still hard to avoid and we almost have to accept it.

ii) The variation in activity start time is affected not only by inhabitant’s preference but also by the other context factors. Identifying those factors may help to increase the detection accuracy . For example, without context information, the start time of Mary’s shower should be from 0800 to 0830 after Debbie’s feedback. However, it would be more accurate if it can distinguish between summer time (0800 to 0820) and winter time (0830, which may be updated as more situations are observed); this requires the system to be able to consider contextual information.

iii) As with duration, there is a question about how long the system should wait before issuing an alert. Related to this is the question about what is a suitable output. For example, if the system could interact with Mary rather than just raising an alarm, then it could ask her if she had forgotten to go to church, or issue other reminders.