159 citations
- Hasselt UniversityBE2 papers
- Indiana University BloomingtonUS2 papers
- University of Alabama at BirminghamUS2 papers
- Humboldt-Universität zu BerlinDE1 paper
- Instituto Tecnológico de Buenos Aires (ITBA)AR1 paper
- Massachusetts Institute of TechnologyUS1 paper
- Universidad de Buenos AiresAR1 paper
- University of AntwerpBE1 paper
- University of WarsawPL1 paper
- Utrecht UniversityNL1 paper
- Vrije Universiteit BrusselBE1 paper
5 papers · 1 filter
Spatial Aggregation: Data Model and Implementation
Leticia Gomez, Sofie Haesevoets, Bart Kuijpers +1
Data aggregation in Geographic Information Systems (GIS) is only marginally present in commercial systems nowadays, mostly through ad-hoc solutions. In this paper, we first present…
The semijoin algebra and the guarded fragment
Dirk Leinders, Jerzy Tyszkiewicz, Jan Van den Bussche
The semijoin algebra is the variant of the relational algebra obtained by replacing the join operator by the semijoin operator. We discuss some interesting connections between the…
Well-Definedness and Semantic Type-Checking in the Nested Relational Calculus and XQuery
Jan Van den Bussche, Dirk Van Gucht, Stijn Vansummeren
Two natural decision problems regarding the XML query language XQuery are well-definedness and semantic type-checking. We study these problems in the setting of a relational fragme…
Relational Association Rules: getting WARMeR
Bart Goethals, Jan Van den Bussche
In recent years, the problem of association rule mining in transactional data has been well studied. We propose to extend the discovery of classical association rules to the discov…
Mining All Non-Derivable Frequent Itemsets
Toon Calders, Bart Goethals
Recent studies on frequent itemset mining algorithms resulted in significant performance improvements. However, if the minimal support threshold is set too low, or the data is high…