Patent ID: 11934563
Assignee: NEC CORPORATION
Field: Computer technology (Electrical engineering)
Classification: CPC G  H | IPC G

Claim 8:
9. A non-transitory computer readable medium storing a program executable by a computer to perform an anomaly detection process comprising:
creating a first binary tree structure for dividing a plurality of data pieces into a plurality of groups;
creating a second binary tree structure for further dividing the data pieces divided into the plurality of groups for each of the plurality of groups;
calculating a score indicating an anomaly level of the plurality of data pieces using a depth from a root node to a leaf node of the second binary tree structure; and
detecting an anomaly based on the calculated score, wherein
the plurality of data pieces are unbalanced data including a majority data group and a minority data group,
the first binary tree structure is created such that the minority data group is included in a predetermined group that is a leaf node of the first binary tree structure, and
usage of the first and second binary tree structures in calculation of the score provides for detection of the anomaly even though the plurality of data pieces are unbalanced.