Uncertainty extensively exists in data and knowledge intensive applications, in which fuzzy
information processing plays a crucial role. Fuzzy sets have been extensively used to …

This comprehensive, bird's view research note combines the state of the art, a brief
presentation of the history and some original solutions, and position like views of some …

This introductory chapter first provides the reader a motivation of the pertinence of the fuzzy
classification approach in the fields of information systems, customer relationship …

In this chapter, we present the Soft-SQL project whose goal is to define a rich extension of
SQL aimed at effectively exploiting flexibility offered by fuzzy sets theory to solve practical …

Nowadays several works have been proposed that allow users to perform fuzzy queries on
relational databases. But most of these systems based on an additional software layer to …

In a previous paper, we presented an approach to calculate relational division in fuzzy
databases, starting with the GEFRED model. This work centered on dealing with fuzzy …

This chapter presents an introduction to fuzzy logic and to fuzzy databases. With regard to
the first topic, we have introduced the main concepts in this field to facilitate the …

In this paper a model of soft aggregation of preferences in flexible database querying is
proposed, based on the vector p-norm operator. The model allows aggregating conditions …

Many years of research related to fuzzy logic and fuzzy set theory extensions to relational
databases have not lead to stable implementations, standardized languages or fuzzy …

This chapter introduces a way to extend the relational model with mechanisms that can
handle imprecise, uncertain, and inconsistent attribute values using fuzzy logic. It describes …