Top-k is the most important query type in OLAP, the most common data warehouses model. Recently, OLAP was extended to represent data ambiguity, specifically imprecision and uncertainty. However, how to deal with top-k queries in uncertain OLAP still remain an unanswered question. This project introduces a complete solution for top-k query in uncertain OLAP including query semantic definition, q...

Abstract Ontology-mediated querying (OMQ) provides a paradigm for query answering according to which users not only records at the database but also implicit information inferred from ontology. A key challenge in OMQ is that may be infinite, cannot stored and queried by off -the -shelf engine. The commonly adopted technique deal with infinite entailments rewriting, which, however, comes cost of...

Point Estimation Using the Kullback-Leibler Loss Function and MML p. 87 Single Factor Analysis in MML Mixture Modelling p. 96 Discovering Associations in Spatial Data An Efficient Medoid Based Approach p. 110 Data Mining Using Dynamically Constructed Recurrent Fuzzy Neural Networks p. 122 CCAIIA: Clustering Categorical Attributes into Interesting Association Rules p. 132 Selective Materializati...

Resolving object references, or reference materialization, is a fundamental operation in object query evaluation. Existing reference materialization techniques fall into two categories: pointer-based and value-based. We identify several drawbacks of existing techniques, and propose a hybrid technique that combines the advantages of each category. This technique relaxes the limitations of valueb...

Representation of context dependent knowledge in the Semantic Web is becoming a recognized issue and a number of DL-based formalisms have been proposed in this regard: among them, in our previous works we introduced the Contextualized Knowledge Repository (CKR) framework. In CKR, contexts are organized hierarchically according to a broader-narrower relation and knowledge propagation across cont...