The concept of a bipolar query is studied in the framework of the flexible fuzzy querying of databases. The focus is on the aggregation of the negative and positive conditions forming a bipolar query. Three formal logical representations of such an aggregation are proposed and analyzed taking into account various possible interpretations of fuzzy logical connectives. The relation to other appro...

We present an overview of the most important proposals for human-oriented query languages for relational databases, based on fuzzy sets theory. To highlight important issues concerning communication with databases, we propose two taxonomies: the first taxonomy deals with flexible query languages in crisp relational databases and the second deals with flexible query languages in fuzzy relational...

Data is often partially known, vague or ambiguous in many real world applications. To deal with such imprecise information, fuzziness is introduced in the classical model. SQLf is one of the practical language to deal with flexible fuzzy querying in Fuzzy DataBases (FDB). However, with a huge amount of fuzzy data, the necessity to work with synthetic views became a challenge for many DB communi...

We present an image retrieval system which permits the user to submit a coarse initial query and continuously re®ne it. The user's relevance feedbacks is modeled by fuzzy sets, and is used to discover and use the more discriminatory features for the given query. The proposed system uses a dissimilarity measure based on the fuzzy integral.

This paper presents results from a study, where fuzzy string matching techniques were used as the sole query translation technique in Cross Language Information Retrieval (CLIR) between the closely related languages Swedish and Norwegian. It is a novel research idea to apply only fuzzy string matching techniques in query translation. Closely related languages share a number of words that are cr...

Topological relationships between spatio-temporal objects are the most fundamental elements in spatio-temporal database systems, GIS, and image database systems. The research issue of modeling topological relationships has increasingly attracted attention, especially for querying of spatio-temporal objects and reasoning of topological relationships. Currently, topological relationship operating...

With the development of cloud computing and big data, data privacy protection has become an urgent problem to solve. Data encryption is the most effective way to protect privacy; however, it will change the data format and result in: 1. database structure and application software will be changed; 2. structured query language (SQL) operations cannot work properly, especially in SQL-based fuzzy q...

Answering complex First-Order Logical (FOL) queries on large-scale incomplete knowledge graphs (KGs) is an important yet challenging task. Recent advances embed logical and KG entities in the same space conduct query answering via dense similarity search. However, most operators designed previous studies do not satisfy axiomatic system of classical logic, limiting their performance. Moreover, t...

Recently years, the nearest neighbor (N-N) query in the spatial database contracts much public attentions and is studied widely. Because of the kinds of the query objects, there are generally three types, point to point (p-p), point to segment (p-s) and segment to segment (s-s). Most of them are precise data, and related documents are rich. However, the research about querying fuzzy objects wit...