A more intuitive, easy and powerful representation, access, and retrieval of information is nowadays a necessary feature of information systems that have become a common instrument for a wide class of users in di?erent areas and for the most diversi?ed tasks. The management of imprecision and uncertainty in databases has become an important research area, which has known an impressive growth. This is testi?ed the increasing number of special sessions in international conferences and workshops devoted to this theme. Generally, this topic matured and developed independently within both the traditional database community and the community of researchers on fuzzy sets, and only very recently some joint initiatives have been undertaken. Since the Workshop titled Supporting Imprecision and Uncertainty in Flexible DataBases we organized within the DEXA Conference in Zaragoza on August 2004, our intent is to bring together a wide community of - searchers in the ?eld of databases, Information Retrieval, Spatial Information Systems, knowledge representation and multimedia, to share experiences and methods concerning the management of uncertainty and imprecision in da- bases. This volume collects a selected number of contributions of well known pioneerresearcheswho,atvariouslevels,proposedmodelsandtheapplication ofmethodstorepresentandmanageuncertaintyandimprecisionindatabases. Many approaches have been proposed in the literature on the modelling of uncertainty and imprecision in databases. To o?er a panoramic view of the methods proposed so far to students, researchers and insightful practitioners, we included in the volume survey chapters on classic topics such as ?exible querying in databases, and database models to represent imperfect data.

Selected contributions on the application of heterogeneous methods for managing uncertainty and imprecision in databases

Klappentext

This volume collects selected contributions on the application of heterogeneous methods for managing uncertainty and imprecision in databases. It contains both survey chapters on classic topics such as "flexible querying in databases", and up to date ontributions
on "database models to represent imperfect data". Further, it includes specific contributions on uncertainty management in database integration, and in representing and
querying semistructured and spatial data. These topics are of particular relevance nowadays with the diffusion of the internet since, most of the time, applications require information spread across several information sources and their integration may result in inconsistent information. Semistructured information querying often calls for the application of approximate matching techniques, and spatial information is often incomplete and imprecise. Reading this volume can serve as a guide to students for having a panoramic view of the methods to manage uncertainty and imprecision in databases proposed so far, to researchers to focus on the most up to date research trends, and to practitioners for having examples in which current databases incorporate flexible functionalities for the management of uncertainty and imprecision.

Inhalt
Database Models and Query Languages.- Flexible Query Languages for Relational Databases: An Overview.- Vacuity-Oriented Generalized Yes/No Queries Addressed to Possibilistic Databases.- On the Applicability of Extended Possibilistic Truth Values in Flexible Database Modelling and Querying.- Preference based Quality Assessment and Presentation of Query Results.- Modeling Fuzzy Information in the EER and Nested Relational Database Models.- Database Integration.- Querying Contradictory Databases by Taking into Account Their Reliability and Their Number.- Database Integrations in Distributed Enterprise Information Systems: A Database Model with Imprecise Information and Query Processing.- Integrating Data Doubtfully.- Semistructured Data Management.- An Overview of Imperfection Representation in Semistructured Data.- A Synopsis based Approach for XML Fast Approximate Querying.- Spatial Databases.- Maximum Entropy Inference for Geographical Information Systems.- Storage and Manipulation of Vague Spatial Objects Using Existing GIS Functionality.- Spatial SQL with Customizable Soft Selection Conditions.