An Application of Improved Gap-BIDE Algorithm for Discovering Access Patterns

Algorithm 2

Get large event set.

ALGORITHM: getLargeEventSet (SDB, 𝑡_session,

min_sup_les)

INPUT: (1) SDB: An input sequence database with time, (2)

𝑡_session: the time user session, (3) min_sup_les: the

minimum support threshold of getting large event set.

OUTPUT: LES: large event set.

(7)scan sequence database; find all candidate events [⟨𝐸1⟩,

⟨𝐸2⟩,…,⟨𝐸𝑗⟩]

(8)group sequences by IP address and 𝑡-session; find all

sessions [𝑆1, 𝑆2,…,𝑆𝑚]

(9)for each candidate event 𝐸𝑗 in session 𝑆𝑚

(10)calculate support for 𝐸𝑗

(11)if (support of 𝐸𝑗 ≥ min_sup_les)

(12)output event 𝐸𝑗 to LES

(13)return