Classical ontologies are not suitable to represent imprecise or vague pieces of information, which has led to fuzzy extensions of Description Logics. In order to support an early acceptance of the OWL 1.1 ontology language, we present DeLorean, the first reasoner that supports a fuzzy extension of the Description Logic SROIQ, closely equivalent to it. It implements some interesting optimization...

Ontologies play a central role in semantic applications: by providing semantics to the given data, they support the integration and automated processing of knowledge. Systems for ontology-based data access do however not take into account both the fuzzy and the temporal nature of the knowledge, which is often inherent in realworld data. In this paper, we propose an approach for temporal query a...

In this work we propose a fuzzy technique to compare XML documents belonging to a semi-structured flow and sharing a common vocabulary of tags. Our approach is based on the idea of representing documents as fuzzy bags and, using a measure of comparison, evaluating structural similarities between them. Then we suggest how to organize the extracted knowledge in a class hierarchy, choosing a techn...

For reasoning over streams of data ontology-based data access is a common approach. The method for answering conjunctive queries (CQs) over DL-Lite ontologies in this setting is by rewritings of the query and evaluation of the resulting query by a data base engine. For streambased applications the classical expressivity of DL-Lite lacks means to handle fuzzy and temporal information. In this pa...

Situation awareness is a more holistic and promising version of context awareness, which is a key to making Ambient Intelligence systems more adaptive and intelligent. A situation-aware computing system needs to represent context information, identify relevant situations based on the context, and then take appropriate actions according to situations. However, two main kinds of uncertainty need ...

This paper shows how a Fuzzy Ontology based approach can improve semantic documents retrieval. After formally defining a Fuzzy Knowledge Base, it is discussed a special type of new non-taxonomic fuzzy relationships, called (semantic) correlations. These correlations, first assigned by experts, are updated after querying, or when a document has been inserted into a database. It is then introduce...

Knowledge management in a structured system is complicated task that requires common, standardized methods are acceptable to all actors system. Ontology, this regard, primary element and plays central role knowledge management, interoperability between various departments, better decision making. The ontology construction for systems comprises logical structural complications. Researchers have ...

The well known Aristotelian syllogistic system consists of 256 moods. We have found earlier that 136 moods are distinct in terms of equal truth ratios that range in τ=[0,1]. The truth ratio of a particular mood is calculated by relating the number of true and false syllogistic cases the mood matches. A mood with truth ratio is a fuzzy-syllogistic mood. The introduction of (n-1) fuzzy existentia...

Ontologies represent a method of formally expressing a shared understanding of information, and have been seen by many authors as a prerequisite for the “Semantic web”. A mapping between query terms and members of an ontology is usually a key part of any ontology enhanced searching tool. However the relative importance of a particular mapping to an overloaded term may be different for different...