Concepts are the foundation for knowledge acquisition through formal concept analysis.In incom-plete formal contexts,in order to express"jointly must possessing(possessed)"and"jointly might possessing(possessed)"relationships,the extent or intent of concepts is usually expressed in the form of interval set.We refer to such concepts as partially-known formal concepts.From the definition of partially-known formal con-cepts,it can be seen that their essence is related to the least and greatest completions of incomplete formal contexts.Therefore,we consider performing operations on the least and greatest completions of incomplete for-mal contexts to find partially-known formal concepts.We construct two new formal contexts based on the appo-sition and subposition of the least and greatest completions.Their concept lattices are isomorphic to the SE-ISI concept lattice and the ISE-SI concept lattice,respectively.Therefore,the new methods for constructing SE-ISI concept lattice and ISE-SI concept lattice are proposed.For the ISE-ISI concept,we use direct sum opera-tion of the least and greatest completions to construct a new formal context,and propose a method to search for the ISE-ISI concepts.
关键词
不完备形式背景/部分已知概念/并置/叠置/直和
Key words
incomplete formal context/partially-known formal concept/apposition/subposition/direct sum
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