Novel Span Measure, Spanning Sets and Applications
  Rough Set based Spanning Sets were recently proposed to deal with
uncertainties arising in the problem in domain of natural language processing
problems. This paper presents a novel span measure using upper approximations.
The key contribution of this paper is to propose another uncertainty measure of
span and spanning sets. Firstly, this paper proposes a new definition of
computing span which use upper approximation instead of boundary regions. This
is useful in situations where computing upper approximations are much more
convenient that computing boundary region. Secondly, properties of novel span
and relation with earlier span measure are discussed. Thirdly, the paper
presents application areas where the proposed span measure can be utilized.
