Research Article

Prediction of Industrial Network Security Situation Based on Noise Reduction Using EMD

Algorithm 1

Noise reduction.
1. noise_filter(data, n): /parameter n refers to the packet size/
2.  length <- length of data
3.  /group data/
4.  group[ ] <- each group contains n consecutive signals
5.  /filter noise/
6.  noise_filter_data = []
7.  for goup_data in the group do
8.    low_num <- the factor with the ranking percentage of B%
9.    high_num <- the factor with the ranking percentage of A%
10.    temp_data = noise_filter_and_replace(goup_data, low_num, high_num)
11.    noise_filter_data.append(tem_data) /Merge all denoised groups/
12. return noise_filter_data
13.
14. /delete outliers and fill the blank places/
15. noise_filter_and_replace(data, low_num, high_num):
16.  /If the noise points exist in the first position or the last position, they need to be processed separately/
17.  for index <-1 to len(data-1) do
18.    if data[index] is noise point then
19.      Find the nearest two non noise points data[first_weight] and data[second_weight] to the left and right
20.      Calculate the distance x, y to the point
21.      first_weight <- y / (x + y)
22.      second_weight <- x / (x + y)
23.      data[index] <- data[first_weight] first_weight + data[second_weight] second_weight
24. return data