Consistent data operations for multi-databases in extended possibility-based data models

Handling Missing Data in Extended Possibility-based Fuzzy Relational Databases

“…The measurement of resemblance between tuples is determined by the minimum of the resemblance of each pair values in these two tuples, following the definition in literature [22]. Given tuples ) ,..., , (…”

“…The measurement proposed by [22] adjusts the possibility distributions of attribute values based on Į-proximately equivalent classes of corresponding domains before measuring semantic equivalence of two values. Let C= (1), the resemblance…”

Lossless Join Decomposition for Extended Possibility-Based Fuzzy Relational Databases

“…Liu et al [13] extended the semantic equivalence to ensure that the result of similarity measure lies within [0, 1]. The measurement adjusts the possibility distributions of values based on -proximate equivalent classes of the domain before measuring their similarity.…”

“…Based on Proposition 11, there must bê1 ∈ ( 1 ) and̂2 ∈ ( 2 ) such that̂1 ≅ 1 and̂2 ≅ 2 because 1 = Π ( , ) ( ) and 2 = Π ( , ) ( ). Since ( ) ≈ Π 1 ( ) ⊗ Π 2 ( ) and 1 (13). Also, we let̂1 and 2 be the tuples such that…”

“…Complicating this problem further, most similarity measures [7,13,14] of values in the form of possibility distribution are not transitive. When tuple redundancy is determined by the similarity measures of nontransitivity, the result of eliminating redundant tuples from a decomposed relation might be not unique (or order sensitive 1 ).…”