Algorithm 1: GettingSIA

Input:Sq{sq1, sq2,…sqn}, a set of sensor sequence

Sensor, sensor set

Output:SIA, two-dimensional tuple of sensor importance

1. SIA←Ø;

2. fre←Ø;//fre is a key-value map to counts the number of activities begin with a certain sensor

3. for each sq in Sq:

4.    Arr←Ø;//Arr is a tuple that counts whether a sensor is present

5.    sv← getT(sq.s1)+1//getT(sq.s1) is employed to get times t of sq.s1

6.    update(fre,{sq.s1,sv})

7.    for each s in sq:

8.        Arr←◡{(sq.s1, 1)}

9.    end for

10.   St←getDict(SIA,sq.s1)//getDict(SIA,sen) is employed to get dict sen

11.   St←sum(St, Arr)}//sum is add Arr to St

12.   update(SIA,{sq.s1,St})

13. end for

14. SIA←div(SIA, fre)//div is used to calculate SIA divided by fre

15. return SIA