Figure 11.

An example of false detection by the scale-adaptive clustering method. The GPS points reflect an indoor staying activity (duration is approximately seventeen hours) inside the building on the lower right corner. However, the algorithm identified two sub-locations: one corresponds to the true activity location (shown inside the red circle) and the other points to a location (shown in the blue circle) that the subject had not been to during the observation period. The false activity location were observed when the subject was staying in the basement where there was substantial GPS signal shielding.