In many applications, spatial data is often prone to uncertainty and imprecision. To model this, fuzzy regions have been developed. Our initial model was a fuzzy set over a two dimensional domain, allowing for fuzzy regions and fuzzy points to be modelled. The model had some limitations: all points where...

An approach to deal with user preference relations, instead of absolute ratings, in recommender systems is discussed. User’s preferences are then ratings expressed qualitatively by using linguistic terms. This is a suitable technique when preferences are imprecise and vague. On the other hand, to avoid...

Web information extraction typically relies on a wrapper, i.e., program code or a configuration that specifies how to extract information for certain fields for a specific website. Manually creating and maintaining wrappers for all target websites is a cumbersome and error-prone task. It may even be...

In this work we propose the use of partially supervised fuzzy clustering to create a two-level indexing structure useful for enabling efficient shape retrieval. Similar shapes are grouped by a fuzzy clustering algorithm that embeds a partial supervision mechanism exploiting domain knowledge expressed...

The paper presents an approach to manage Volunteered Geographic Information (VGI) to point out anomalous conditions of the environment. This can help administrators in charge of the governance and maintenance activities of the territory to plan mitigation and safeguard interventions. To this end, a system...

Fusion functions are important data integration tools that map a multiset of objects (i.e., the sources) onto a single object (i.e., the solution). Traditionally, it is assumed that the objects of interest are single-valued. In this paper, it will be assumed that each object has a multi-valued data structure,...

Information systems model parts of reality by representing properties of real-world objects or concepts. As real objects or concepts often have temporal aspects, temporal notions such as time intervals are often represented. However, these may contain imperfections like uncertainties, complicating their...

Querying a database in an intuitive way is becoming more important. Users expect their tools to present an easy-to-use interface that can interpret complex search criteria. These criteria can be optional, mandatory, unwanted or grouped together, according to what the developer of a tool wishes to offer...

We propose a conceptually new type of bipolar queries meant as those in which a required condition, to be necessarily satisfied, and desired condition, to be satisfied if possible, are included. In the new type of bipolar queries, termed compound bipolar queries, both the required and desired conditions...