On Armstrong relations for strong dependencies

The strong dependency has been introduced and axiomatized in [2], [3], [4], [5]. The aim of this paper is to investigate on Armstrong relations for strong dependencies. We give a necessary and sufficient condition for an abitrary relation to be Armstrong relation of a given strong scheme. We also g...

Teljes leírás

Elmentve itt :
Bibliográfiai részletek
Szerzők: Thi Vu Duc
Nguyen Hoang Son
Dokumentumtípus: Cikk
Megjelent: 2006
Sorozat:Acta cybernetica 17 No. 3
Kulcsszavak:Számítástechnika, Kibernetika
Tárgyszavak:
Online Access:http://acta.bibl.u-szeged.hu/12780
Leíró adatok
Tartalmi kivonat:The strong dependency has been introduced and axiomatized in [2], [3], [4], [5]. The aim of this paper is to investigate on Armstrong relations for strong dependencies. We give a necessary and sufficient condition for an abitrary relation to be Armstrong relation of a given strong scheme. We also give an effective algorithm finding a relation r such that r is Armstrong relation of a given strong scheme G = (U,S) (i.e. Sr = S+, where Sr is a full family of strong dependencies of r, and S+ is a set of all strong dependencies that can be derived from S by the system of axioms). We estimate this algorithm. We show that the time complexity of this algorithm is polynomial in |U| and |S|.
Terjedelem/Fizikai jellemzők:521-531
ISSN:0324-721X