After introducing the lowest common ancestor, the
semantic distance calculation method and the semantic
similarity calculation method are given in Formula (6)
and (7) respectively.
dist (x1, x2)=(·
wvk+(Nx1+Nx2)/(Nx1+Nx2+2Nh)) (6)
simpp(x1, x2)= · (1/edist(x1, x2)) (7)
Herein,
wvk is the sum of weighted distances of
each edge between concepts, Nxi represents the distance
from the node i to the lowest common ancestor, Nh
represents the distance from the lowest common ancestor
to the root node, and are regulatory factors.