“…In recent years, discovery of association rules [1,3,14,19,21,31] and sequential patterns [2,5,6,11,12,15,20,[23][24][25][26]32,34] has been a major research issue in the area of data mining and knowledge discovery. Typical association rules usually reflect related events occurring at the same time, and sequential patterns represent commonly occurring sequences that are in a time order.…”