tailieunhanh - Phụ thuộc dữ liệu trong cơ sở dữ liệu quan hệ với thông tin ngôn ngữ

On this new viewpoint, in the present paper a notion of “fuzzy” functional dependencies in these databases will be defined reasonably. These new dependencies will be examined in the context of traditional functional dependencies, which play as syntaxtical constraints of the databases under consideration. Relationship between these two kinds of such dependencies will also be considered. | ’ Tap ch´ Tin hoc v` Diˆu khiˆn hoc, , (2007), 164–178 ı e e . . a ` . . ’ . ˜. ˆ ˆ ˜. ˆ ˆ PHU THUOC DU LIEU TRONG CO SO DU LIEU QUAN HE . . . . . ˆ ˆ ˜ ´.I THONG TIN NGON NGU. VO ˜ ˆ ˘ NGUYEN VAN LONG Khoa Cˆng nghˆ Thˆng tin, Dai hoc Giao thˆng Vˆn tai H` Nˆi o e o o a ’ a o . . . . . Abstract. Relational databases with linguistic data based on hedge algebras - based semantics were introduced and investigated in [3], in which the evaluation of queries containing linguistic data was transformed into that of traditional queries. On this new viewpoint, in the present paper a notion of “fuzzy” functional dependencies in these databases will be defined reasonably. These new dependencies will be examined in the context of traditional functional dependencies, which play as syntaxtical constraints of the databases under consideration. Relationship between these two kinds of such dependencies will also be considered. ´ ´ . ´ ’ a T´m t˘t. CSDL ngˆn ng˜. v´.i ng˜. ngh˜ trˆn c´ch tiˆp cˆn dai sˆ gia tu. d˜ nghiˆn c´.u o a o u o e a e a e u u ıa . . . o . gi´ c´c truy vˆ n liˆn quan dˆn thˆng tin ngˆn ng˜. vˆ viˆc ´ ´ e ` e o e e o o u trong [3], trong d´ viˆc lu . a a a e . . . . gi´ kinh diˆn. Trˆn co. so. d´, phu thuˆc h`m m`. trong CSDL ngˆn ng˜. s˜ dinh ’ ’ o a o u e e e o a o thao t´c lu . a . . . . ’ ’ u u e a o a o u ’ o o a ngh˜ v` nghiˆn c´.u trong ng˜. canh v´.i phu thuˆc h`m kinh diˆn v` c´ r`ng buˆc CSDL o. m´.c c´ ıa a e u . . . ´i quan hˆ gi˜.a hai loai phu thuˆc n`y c˜ ng xem x´t. e o a u ph´p. Mˆ a o e u . . . . . ’. A ˆ 1. MO D` U ´ ’ u e Co. so. d˜. liˆu (CSDL) quan hˆ m`. d˜ nghiˆn c´.u ph´t triˆ n t`. cuˆi nh˜.ng n˘m 70 e o a e u a e’ u o u a . . . . d´ d˜ dung ([1, 2, 17, 21, 22]) dˆ giai quyˆt c´c b`i to´n tiˆn ˜ ´ ´ e thˆ ky XX v` t` o a e’ ’ a u e’ ’ e a a a . . . .`.ng thˆng tin m`., khˆng ch˘c ch˘n. Nh˜.ng dung hˆ thˆng CSDL trong ´ ´ ´ trong mˆi tru .