Extensions and intentions in the rough set theory
Information Sciences: an International Journal
Relational interpretations of neighborhood operators and rough set approximation operators
Information Sciences—Informatics and Computer Science: An International Journal
Rules in incomplete information systems
Information Sciences: an International Journal
Rough Sets: Theoretical Aspects of Reasoning about Data
Rough Sets: Theoretical Aspects of Reasoning about Data
A comparative study of some generalized rough approximations
Fundamenta Informaticae
A Generalized Definition of Rough Approximations Based on Similarity
IEEE Transactions on Knowledge and Data Engineering
Approximation Spaces Based on Relations of Similarity and Dissimilarity of Objects
Fundamenta Informaticae - Special Issue on Concurrency Specification and Programming (CS&P)
Relationship between generalized rough sets based on binary relation and covering
Information Sciences: an International Journal
A comparison of two types of rough sets induced by coverings
International Journal of Approximate Reasoning
Incomplete data and generalization of indiscernibility relation, definability, and approximations
RSFDGrC'05 Proceedings of the 10th international conference on Rough Sets, Fuzzy Sets, Data Mining, and Granular Computing - Volume Part I
Characteristic relations for incomplete data: a generalization of the indiscernibility relation
Transactions on Rough Sets IV
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Unit operations are some special functions on sets. The concept of the unit operation originates from researches of U. Wybraniec-Skardowska. The paper is concerned with the general properties of such functions. The isomorphism between binary relations and unit operations is proved. Algebraic structures of families of unit operations corresponding to certain classes of binary relations are considered. Unit operations are useful in Pawlak's Rough Set Theory. It is shown that unit operations are upper approximations in approximation space. We prove, that in the approximation space (U, R) generated by a reflexive relation R the corresponding unit operation is the least definable approximation if and only if the relation R is transitive.