This work is supported by the Hungarian Scientific Research Fund (OTKA), grant T042706.
Current methods of database schema design are usually based
on modeling the real world as entity (or object) classes with relationships
among them. Properties of relationships can be described by semantical
database constraints. One of them is functional dependency, which has a
key role in traditional database design. The three basic types of binary relationships
that can be described by functional...
There are limitations in recent research undertaken on attribute reduction in incomplete decision systems. In this paper, we propose a distance-based method for attribute reduction in an incomplete decision system. In addition, we prove theoretically that our method is more effective than some other methods.
Sequential pattern mining is an important subject in data mining with broad
applications in many different areas. However, previous sequential mining
algorithms mostly aimed to calculate the number of occurrences (the support)
without regard to the degree of importance of different data items.
In this paper, we propose to explore the search space of subsequences
with normalized weights. We are not only interested in the number
of occurrences of the sequences (supports of sequences), but also concerned
about...
In fuzzy granular computing, a fuzzy granular structure is the collection of
fuzzy information granules and fuzzy information granularity is used to
measure the granulation degree of a fuzzy granular structure.
In general, the fuzzy information granularity characterizes discernibility ability
among fuzzy information granules in a fuzzy granular structure. In recent years,
researchers have proposed some concepts of fuzzy information granularity based
on partial order relations. However, the existing...
In recent years, rough set approach computing issues concerning
reducts of decision tables have attracted the attention of many researchers.
In this paper, we present the time complexity of an algorithm
computing reducts of decision tables by relational database approach. Let
DS = (U, C ∪ {d}) be a consistent decision table, we say that A ⊆ C is a
relative reduct of DS if A contains a reduct of DS. Let s = <C ∪ {d} , F>
be a relation schema on the attribute set C ∪ {d}, we say that A ⊆ C...
Download Results (CSV)