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Missing value semantics and absent value semantics for incomplete information in object-oriented rough set models. (English) Zbl 1144.68378
Bello, Rafael (ed.) et al., Granular computing: At the junction of rough sets and fuzzy sets. Several papers based on the presentations at the 1st international symposium of fuzzy and rough sets (ISFUROS 2006), Santa Clara, Cuba, December 5–8, 2006. Berlin: Springer (ISBN 978-3-540-76972-9/hbk). Studies in Fuzziness and Soft Computing 224, 3-21 (2008).
Summary: We consider the “missing value” semantics and the “absent value” semantics in object-oriented rough set models proposed by the authors. The Object-Oriented Rough Set model (OORS) is an extension of rough set theory by introducing object-oriented paradigm, and treats semi-structured objects and hierarchies among objects based on is-a and has-a relationships. We propose null value objects of OORS and revise Kryszkiewicz’s tolerance relations, which characterize “missing value” semantics in OORS as incompleteness by “lack of parts”. Moreover, we discuss connections between “absent value” semantics and is-a relationship in OORS, and revise similarity relations proposed by Stefanowski and Tsoukias, which characterize “absent value” semantics in OORS as incompleteness by difference of architecture of objects.
For the entire collection see [Zbl 1132.68003].
68T30 Knowledge representation