Uncovering Abnormal Behavior Patterns from Mobility Trajectories

. 2021 May 19;21(10):3520. doi: 10.3390/s21103520

Algorithm 3 Judge wandering behavior.

Input:
Divide the trajectory evenly into a area according to time.

set threshold : $m a x s c a l e, v e c d i s, m a x s u b$ .
Output:
the trajectory if has wandering behavior. )
1:
for $i = 0$ to a do
2:
Calculate the displacement and distance of the user’s movement in each area;
3:
if $d i s p l a c e m e n t - d i s t a n c e > m a x s u b$ then
4:
$v e c d i s = v e c d i s + 1$ ;
5:
end if
6:
end for
7:
if $\frac{v e c d i s}{a} > m a x s c a l e$ then
8:
return true;
9:
else
10:
return false;
11:
end if