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Dissertation
A Self-Organising Multi-Agent Knowledge Base
(2021-12)
Digitale Städte sind zunehmend auf IT- und Kommunikationsinfrastruktur angewiesen. Sie können als große verteilte Systeme betrachtet werden, die aus heterogenen und autonomen Teilnehmern bestehen. Besonders in Notfall- und Krisensituationen muss kritisches Wissen, beispielsweise über verletzte Personen oder beschädigte Infrastruktur, zuverlässig auch unter eingeschränkter Kommunikation erreichbar sein. In einer solchen Umgebung würde eine zentrale Verwaltung des kritischen Wissens einen Engpass verursachen. Daher ...
Aufsatz
Hierarchies of conceptual scales
(1999)
Formal Concept Analysis allows to derive conceptual hierarchies from data tables. Formal Concept Analysis is applied in various domains, e.g., data analysis, information retrieval, and knowledge discovery in databases. In order to deal with increasing sizes of the data tables (and to allow more complex data structures than just binary attributes), conceputal scales habe been developed. They are considered as metadata which structure the data conceptually. But in large applications, the number of conceptual scales ...
Preprint
Efficient data mining based on formal concept analysis
(2002)
Formal Concept Analysis is an unsupervised learning technique for conceptual clustering. We introduce the notion of iceberg concept lattices and show their use in Knowledge Discovery in Databases (KDD). Iceberg lattices are designed for analyzing very large databases. In particular they serve as a condensed representation of frequent patterns as known from association rule mining. In order to show the interplay between Formal Concept Analysis and association rule mining, we discuss the algorithm TITANIC. We show that ...
Aufsatz
On-line analytical processing with conceptual information systems
(1998)
A conceptual information system consists of a database together with conceptual hierarchies. The management system TOSCANA visualizes arbitrary combinations of conceptual hierarchies by nested line diagrams and allows an on-line interaction with a database to analyze data conceptually. The paper describes the conception of conceptual information systems and discusses the use of their visualization techniques for on-line analytical processing (OLAP).
Aufsatz
A geometrical heuristic for drawing concept lattices
(1995)
Concept lattices are used in formal concept analysis to represent data conceptually so that the original data are still recognizable. Their line diagrams should reflect the semantical relationships within the data. Up to now, no satisfactory automatic drawing programs for this task exist. The geometrical heuristic is the most successful tool for drawing concept lattices manually. It ueses a geometric representation as intermediate step between the list of upper covers and the line diagram of the lattice.
Preprint
Efficient mining of association rules based on formal concept analysis
(2005)
Association rules are a popular knowledge discovery technique for warehouse basket analysis. They indicate which items of the warehouse are frequently bought together. The problem of association rule mining has first been stated in 1993. Five years later, several research groups discovered that this problem has a strong connection to Formal Concept Analysis (FCA). In this survey, we will first introduce some basic ideas of this connection along a specific algorithm, TITANIC, and show how FCA helps in reducing the ...