Table 2: List of notations.

NotationExplanationNotationExplanation

RThe CPS dataset , The atypical data records
SThe sensor set , The sensors
TThe time period , The time windows
SFThe spatial featureTFThe temporal feature
The severity measure The total severity
The atypical events The spatial region
The analytical query The atypical clusters
The agg. severity by The agg. severity by
The time threshold The distance threshold
The severity threshold The similarity threshold