We present an application of association rules and fuzzy association rules to find new terms that help the user to search in the web. A first query is made to the web and an initial set of documents is retrieved. Considering the terms of the collection as items, text transactions are constructed and association rules are extracted. Fuzzy association rules are also considered when the presence o...

An extended fuzzy relational database model is proposed. The proposed model uses first-order logic to express both imprecision and uncertainty in data. A method for measuring the quality of answers to Select-Project-Join (SPJ) queries is described. The method of measurement determines the extent to which how much satisfactory information is provided, and how much extra information is required t...

Dynamic invocation of services in O-O execution environments requires identification of server objects which are “fit” to a certain task on the basis of available functional and non-functional information. CORBAcompliant environments store such information in a Trader system which can be browsed or queried by client objects. In this paper a fuzzy data model is proposed as the basis of the desig...

This paper proposes an approach aimed at obviating empty answers for a family of conjunctive queries involving Boolean or fuzzy value constraints. Contrary to the approaches based on a relaxation of the predicates involved in the query, the principle suggested here consists in replacing the query by another one similar which has been processed previously and whose answer is known to be non-empt...

Fuzzy Description Logics (FDLs) generalize crisp ones by providing membership degree semantics. To offer efficient query answering for FDLs it is desirable to extend the rewriting-based approach for DL-Lite to its fuzzy variants. For answering conjunctive queries over fuzzy DL-LiteR ontologies we present an approach, that employs the crisp rewriting as a black-box procedure and treats the degre...

Most query languages are designed to retrieve information from databases containing precise and certain data using precisely specified commands. Application of fuzzy set theory to relational data models has been studied extensively in recent years. This paper presents a calculus for fuzzy queries on a fuzzy entity-relationship model. The paper, first, defines a fuzzy entity-relationship model c...

In this paper, we present a new method for fuzzy query processing for document retrieval based on extended fuzzy concept networks. In an extended fuzzy concept network, there are four kinds of fuzzy relationships between concepts, i.e., fuzzy positive association, fuzzy negative association, fuzzy generalization, and fuzzy specialization. An extended fuzzy concept network can be modeled by a re...

In this paper we present an extension of the XPath query language for the handling of flexible queries. In order to provide ranked answers, our approach proposes fuzzy variants of and, or and avg operators for XPath conditions, as well as two structural constraints, called down and deep, for which a certain degree of relevance is associated. Our proposal has been implemented with a fuzzy logic ...

In information retrieval, the uncertain implication D −→ RQ has been different logical status. In this paper, we propose another way to consider this implication in fuzzy context. We introduce a logical formulation based on logical consequence and an evaluation based on an extension of fuzzy Galois connection. The proposed matching function deals with different semantics associated with terms d...