A Collaborative Filtering Method for Operation Maintenance Behavior in Power Monitoring Systems

Algorithm 2

Workflow of computing user and resource models by alternating least squares method.

Input: Behavior frequency matrix P_M×N of resource access by users

Output: User matrix X_M×X and resource matrix Y_N×k

1 Construct the loss function Loss

2 Randomly initialize user model X and resource model Y

3while (Loss does not converge)

4   for i from 1 to M

5      for j from 1 to N

6        if (p_i,jis recorded in the training set)

7           e = X_iY_j - p_i,j /Predictive value of model- Corresponding value of training set/

8        end if

9x_i,j = x_i,j-2 alpha(ey_i,j+lambadax_i,j)/alpha represents the learning rate/

10y_i,j = y_i,j-2 alpha(ex_i,j+lambaday_i,j) /delta represents the regular terms/

11end for

12end for

13 Output X_i and Y_jas user matrix X_M×k and resource matrix Y_N×k