Research Article

A Detection Method for Abnormal Transactions in E-Commerce Based on Extended Data Flow Conformance Checking

Algorithm 2

Abnormal order detection.
Input:
1. The outlier sequence set is composed of the transition set in Algorithm 1;
2. The set of user’s history transaction behavior patterns and the normal patterns , and its transition sets is represented by ;
3. The weight set of each activity is sequence , where ;
4. The weight of each normal pattern is sequence , where ;
5. is the set of all normal behavior patterns ;
6. is the set of matching results of each activity;
Output: the path to be selected by the system.
1. Calculate the matching results between and and store it in , initial ;
2. While the elements of the set N are not all traversed Do
   select from ;
  While the elements of the set are not all traversed Do
   select from ;
  IfThen
   ;
  Else
   ;
  End
End
3. Calculate each matching results under the current normal behavior patterns by formula (2);
4. Calculate the final anomaly detection result by formula (3);
 4.1 IfThen
  ;
 4.2 Else
  ;