Research Article

Characterizing Network Anomaly Traffic with Euclidean Distance-Based Multiscale Fuzzy Entropy

Algorithm 1

EDM-fuzzy algorithm.
Inputs:
  Time series: .
  Time scale: .
  Vector dimension: .
  Tolerance coefficient: .
  Standard deviation of time series X : SD.
Output:
  EDM-Fuzzy entropy value of time series X at time scale τ.
(1)for to
(2)  ;
(3)  for to
(4)   Coarse-graining the time series ;
(5)  end for
(6)end for
(7)for to
(8)  for to
(9)   Calculate the mean of each vector
     ;
(10)   Move the vectors
      ;
(11)  end for
(12)  for to
(13)   for to
(14)    Calculate the Euclidean distance of the two
      vectors and :
       ;
(15)    Calculate the similarity between and vectors
       ;
(16)   end for
(17)   Calculate the average similarity between vector
       and the other vectors
       ;
(18)  end for
(19)   Compute the average of , that is,
      ;
(20)   Set dimensional length of vectors to and repeat step 8∼19 to calculate average similarity between each pair of points vectors in coarse-grained time series; you can get and
(21)    ;
(22)    ;
(23)   Compute the Euclidean distance based on fuzzy
    sample entropy value for every ,
      ;
(24)end for
(25)Compute the fuzzy sample entropy value for the original time series at time scale
    .