384 Chapter 8 Fuzzy InFormatIon retrIeval
Relational division is another way to handle fuzzy query processing. A
relation of a certain degree is divided by a relation of smaller degree. The
relational division operator is extended to the fuzzy division operator to
process fuzzy queries. An alpha-cut threshold defines a minimum degree of
membership value. Without it, the amount of information retrieved by the
query processor can be enormous. It minimizes the amount of unneces-
sary information since any membership values less than the threshold are
excluded from the candidate list. A restricted set of more reliable informa-
tion is obtained by establishing an appropriate alpha-cut threshold to define
a boundary between useful and ...