Interval valued intuitionistic fuzzy sets
Fuzzy Sets and Systems
More on intuitionistic fuzzy sets
Fuzzy Sets and Systems
Vague sets are intuitionistic fuzzy sets
Fuzzy Sets and Systems
Fuzzy Sets and Systems
Intuitionistic Fuzzy Sets: Theory and Applications
Intuitionistic Fuzzy Sets: Theory and Applications
SQLf: a relational database language for fuzzy querying
IEEE Transactions on Fuzzy Systems
Maintaining consistency of vague databases using data dependencies
Data & Knowledge Engineering
Mining vague association rules
DASFAA'07 Proceedings of the 12th international conference on Database systems for advanced applications
Mining hesitation information by vague association rules
ER'07 Proceedings of the 26th international conference on Conceptual modeling
Handling inconsistency of vague relations with functional dependencies
ER'07 Proceedings of the 26th international conference on Conceptual modeling
An improved fuzzy support vector machine for credit rating
NPC'07 Proceedings of the 2007 IFIP international conference on Network and parallel computing
Fuzzy clustering based on vague relations
FSKD'06 Proceedings of the Third international conference on Fuzzy Systems and Knowledge Discovery
Preference functional dependencies for managing choices
ER'06 Proceedings of the 25th international conference on Conceptual Modeling
A novel intuitionistic fuzzy clustering method for geo-demographic analysis
Expert Systems with Applications: An International Journal
Vague Correlation Coefficient of Interval Vague Sets
International Journal of Fuzzy System Applications
Risk analysis of combustion system using vague ranking method
Journal of Intelligent & Fuzzy Systems: Applications in Engineering and Technology
Hi-index | 0.00 |
In the real world there are vaguely specified data values in many applications, such as sensor information. Fuzzy set theory has been proposed to handle such vagueness by generalizing the notion of membership in a set. Essentially, in a Fuzzy Set (FS) each element is associated with a point-value selected from the unit interval [0,1], which is termed the grade of membership in the set. A Vague Set (VS), as well as an Intuitionistic Fuzzy Set (IFS), is a further generalization of an FS. Instead of using point-based membership as in FSs, interval-based membership is used in a VS. The interval-based membership in VSs is more expressive in capturing vagueness of data. In the literature, the notions of IFSs and VSs are regarded as equivalent, in the sense that an IFS is isomorphic to a VS. Furthermore, due to such equivalence and IFSs being earlier known as a tradition, the interesting features for handling vague data that are unique to VSs are largely ignored. In this paper, we attempt to make a comparison between VSs and IFSs from various perspectives of algebraic properties, graphical representations and practical applications. We find that there are many interesting differences from a data modelling point of view. Incorporating the notion of VSs in relations, we describe Vague SQL (VSQL), which is an extension of SQL for the vague relational model, and show that VSQL combines the capabilities of a standard SQL with the power of manipulating vague relations. Although VSQL is a minimal extension to illustrate its usages, VSQL allows users to formulate a wide range of queries that occur in different modes of interaction between vague data and queries.