An index structure for fuzzy databases

Fuzzy querying involves more complex processing than ordinary querying does. In addition, a larger number of tuples will possibly be selected by fuzzy conditions compared to the crisp ones. The current index structures are inefficient in representing and dealing with uncertain and fuzzy data. In this paper we extend one of the multi-dimensional data structures, namely Multi Lever Grid File (Whang and Krishnamurty, 1991) for an efficient access to both crisp and fuzzy data. In order to take advantage of the indexing data structure proposed here, we first partition uncertain data in a way that accessing such data in a database is reasonably efficient. Therefore, we also focus on the issue of preparation of uncertain data before building the access structure. Then we compare the one proposed here with sequential access along with experimental results.
Proceedings of IEEE 5th International Fuzzy Systems


Halıcı, Uğur (1991-07-01)
An optimistic scheme, called ODL, which uses dummy locks to test the validity of a transaction for concurrency control in distributed database systems, is suggested. The dummy locks are long-term locks; however, they do not conflict with any other lock. By the use of long-term dummy locks, the need for the information about the write sets of validated transactions is eliminated and during the validation test only the related sites are checked. Also, the transactions to be aborted are immediately recogniz...
A complete axiomatization for fuzzy functional and multivalued dependencies in fuzzy database relations
Yazıcı, Adnan (1996-09-11)
In this paper we first introduce a new definition for the conformance of tuples existing in a fuzzy database relation. Then we give the formal definitions of fuzzy functional and multivalued dependencies on the basis of the conformance values presented here. Secondly, we list the inference rules after showing that both fuzzy functional and multivalued dependencies are consistent, that is, they reduce to those of the classic functional and multivalued dependencies when crisp attributes are involved. Finally,...
An indexing technique for similarity-based fuzzy object-oriented data model
Yazıcı, Adnan; Koyuncu, M (2004-01-01)
Fuzzy object-oriented data model is a fuzzy logic-based extension to object-oriented database model, which permits uncertain data to be explicitly represented. One of the proposed fuzzy object-oriented database models based on similarity relations is the FOOD model. Several kinds of fuzziness are dealt with in the FOOD model, including fuzziness between object/class and class/superclass relations. The traditional index structures are inappropriate for the FOOD model for an efficient access to the objects wi...
A Survey on cryptographic protocols using pairing-based cryptography
Fetvacı, Şeyma; Cenk, Murat; Department of Cryptography (2019)
With the thousands of works on pairing-based cryptography, the purpose of using pairings in the protocols/schemes have changed. Before, they were used just to attack the systems. Nowadays, they have been used to design such new cryptosystems that there were no applicable methods before for these protocols like Joux's key agreement scheme. The main purpose of this thesis is to analyze how some of these protocols use pairings-based cryptography in their schemes and what they achieve with these schemes. We fur...
Using fuzzy Petri nets for static analysis of rule-bases
Bostan-Korpeoglu, B; Yazıcı, Adnan (2004-01-01)
We use a Fuzzy Petri Net (FPN) structure to represent knowledge and model the behavior in our intelligent object-oriented database environment, which integrates fuzzy, active and deductive rules with database objects. However, the behavior of a system can be unpredictable due to the rules triggering or untriggering each other (non-termination). Intermediate and final database states may also differ according to the order of rule executions (non-confluence). In order to foresee and solve problematic behavior...
Citation Formats
A. Yazıcı, “An index structure for fuzzy databases,” New Orleans, LA, USA, 1996, p. 1375, Accessed: 00, 2020. [Online]. Available: