Results 251 to 260 of about 9,774 (301)

Computing iceberg concept lattices with Titanic

open access: yesData and Knowledge Engineering, 2002
International audienceWe introduce the notion of iceberg concept lattices and show their use in knowledge discovery in databases. Iceberg lattices are a conceptual clustering method, which is well suited for analyzing very large databases.
Gerd Stumme   +2 more
exaly   +3 more sources

Constraint heterogeneous concept lattices and concept lattices with heterogeneous hedges

Fuzzy Sets and Systems, 2016
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
L'ubomír Antoni   +2 more
openaire   +1 more source

A Generalized Concept Lattice

Logic Journal of the IGPL, 2005
Summary: We describe a new approach to fuzzify a concept lattice and we show that it is a generalization and common platform for already known approaches: the classical crisp Ganter \& Wille [\textit{B. Ganter} and \textit{R. Wille}, Formal concept analysis. Berlin: Springer (1999; Zbl 0909.06001)] case, the fuzzy Pollandt [\textit{S. Pollandt}, in: G.
openaire   +2 more sources

Concept Approximation in Concept Lattice

2007
In this paper we present a novel approach to the concept approximations in concept lattice. Using the similar idea of rough set theory and unique properties of concept lattice, upper and lower approximations of any object or attribute set can be found by exploiting meet-(union-)irreducible elements in concept lattice, the approximations can be ...
Keyun Hu   +4 more
openaire   +1 more source

Decompositions of Concept Lattices

1999
A complex concept lattice can possibly be split up into simpler parts. Here the mathematical model must prove its worth by providing efficacious and versatile methods for the decomposition. Every such decomposition principle can be reversed to make a construction method.
Bernhard Ganter, Rudolf Wille
openaire   +1 more source

Decomposition of Relations and Concept Lattices

Fundamenta Informaticae, 2013
We introduce the decomposition of an arbitrary relation into a sequential composition of three relations, viz. of a mapping with a partial order and then the transpose of a mapping. After presenting some basic properties, we investigate the specific classes of junkfree, irreducible and minimal decompositions and show that for all relations a minimal ...
Rudolf Berghammer, Michael Winter 0001
openaire   +2 more sources

Concept Lattices of Subcontexts of a Context

Fundamenta Informaticae, 2009
As an effective tool for data analysis and knowledge processing, the theory of concept lattices has been studied extensively and applied to various fields. In order to discover useful knowledge, one often ignores some attributes according to a particular purpose and merely considers the subcontexts of a rather complex context.
Xia Wang, Wenxiu Zhang
openaire   +2 more sources

Constructions of concept lattices

1999
A construction method by means of which we obtain from two contexts K1 and K2 a new context, let us say K, can only be a useful construction principle for concept lattices, if it is invariant under reduction. This means that, if the same construction is applied to contexts whose concept lattices are isomorphic to those of K1 and K2, then the concept ...
Bernhard Ganter, Rudolf Wille
openaire   +1 more source

Trees in Concept Lattices

2007
The paper presents theorems characterizing concept lattices which happen to be trees after removing the bottom element. Concept lattices are the clustering/classification systems provided as an output of formal concept analysis. In general, a concept lattice may contain overlapping clusters and need not be a tree.
Radim Belohlávek   +3 more
openaire   +1 more source

Properties of concept lattices

1999
Mathematical lattice theory classifies lattices according to their structural properties. The most important such property, namely distributivity, has already been mentioned in Section 0.3 and has been used several times since then. Now we shall examine it a little more closely. For this purpose, we concentrate on doubly founded lattices, a choice that
Bernhard Ganter, Rudolf Wille
openaire   +1 more source

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