  In this paper, we investigate qualitative integrals (generalizations of
Sugeno integral) acting on recently introduced Dragonfly algebras. These
algebras are designed for applications in data analysis (based on fuzzy
relational compositions) when some data are unknown (e.g., missing). Unknown
data are represented by the additional dummy value. Definitions of operations
on Dragonfly algebras follow lower estimation strategy, i.e., results of
operations can be interpreted as lower estimations of results obtained when
unknown values are replaced by known ones. We define qualitative integrals on
Dragonfly algebras and show their monotonicity. We also prove results
characterizing when these integrals return known (or unknown) values. We also
present an illustrative example and hint directions of further research.
