Carlos Manuel Rodrigues Machado Autonomic Ubiquitous Computing

The events capture per day have a calculated a mean value of 5431 events, with a standard
deviation of 2158 events. These simple statistical measurements can be used to create a common-
day-index which is useful to augment the confidence in pattern recognition based on a statistical
measure algorithms.
The histogram presented in Figure 33 shows the distribution of the accumulated events per
day. It shows that 44% of the day has accumulated events between 4000 and 7000. The figure also
divides the classes into the 4 quarters of the years. This division allows detecting that the days from
the 1 st and the 2 nd quarters of the year accumulate less events compared to those from the 3 rd and
4 th quarters. This indicates that the accumulated events per day change along the year, pointing out
that the behaviour of the users change throughout time.
Days
180
160
140
120
100
80
60
40
20
0
4th Quarter
3rd Quarter
2nd Quarter
1st Quarter
1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 11000 12000 13000 14000
Intervals of accumulated events
Figure 33 – Histogram distribution for the accumulated events/day (during 2 years)
- 143 -