Here we use the semantic correlations defined in Section 3 to derive the semantic relationship between t j and any other term t k .
: For each pair (t j ,t k ), k=1,..n, set For all t k with Link(t j ,t k )=1, we form a semantic group centered around t j denoted by: Here t j is the main keyword of node G j and is denoted by main(G j )=t j .