Fuzzy databases with linguistic data based on hedge algebras were introduced, where the evaluation of queries containing linguistic data was transformed into that of traditional queries. On this new viewpoint, in this paper a notion of linear functional dependencies in these databases will be defined reasonably. The problems related to increasingly and decreasingly linear functional dependencies will be considered. | ’ Tap ch´ Tin hoc v` Diˆu khiˆn hoc, , (2008), 20–31 ı a ` e e . . . . . ’ . ˜. ˆ ˆ ˆ `. PHU THUOC DO N DIEU TRONG CO SO DU LIEU MO . . . . ´ ’ ´ ’. ˆ ´ ˆ ˆ ˜. ˆ THEO CACH TIEP CAN NGU NGH˜ LAN CAN CUA DAI SO GIA TU IA ˆ . . . ˜ ` ˜ ˆ ´ ˆ ˆ ˆ ` NGUYEN CAT HO1 , NGUYEN CONG HAO2 1 Viˆn e . Cˆng nghˆ thˆng tin, Viˆn Khoa hoc v` Cˆng nghˆ Viˆt Nam o e o e e e . . . a o . . 2 Dai hoc khoa hoc Huˆ ´ e . . . Abstract. Fuzzy databases with linguistic data based on hedge algebras were introduced in [1, 6, 15], where the evaluation of queries containing linguistic data was transformed into that of traditional queries. On this new viewpoint, in this paper a notion of linear functional dependencies in these databases will be defined reasonably. The problems related to increasingly and decreasingly linear functional dependencies will be considered. ´ ´ . ´ ’ u e ’ a T´m t˘t. Co. so. d˜. liˆu m`. v´.i ng˜. ngh˜ trˆn c´ch tiˆp cˆn dai sˆ gia tu. d˜ nghiˆn c´.u o a o o u ıa . e a e a e u . . o . . gi´ c´c truy vˆn liˆn quan dˆn thˆng tin ngˆn ng˜. ´ ´ o a e e o o u trong [1, 6, 15], trong d´ c´c viˆc lu . a a a e . . ’ ` e ’ o vˆ viˆc thao t´c gi´ kinh diˆn. Trˆn co. so. d´, trong b`i b´o n`y kh´i niˆm phu thuˆc h`m e . a a e e a a a a e o a . . . . ´ e ´ ’ u e diˆu trong co. so. d˜. liˆu m`. s˜ dinh ngh˜ v` nghiˆn c´.u. C´c vˆn dˆ liˆn quan dˆn phu e o e ıa a e u a a ` e e . . . . . ’ thuˆc h`m diˆu t˘ng v` phu thuˆc h`m diˆu giam c˜ ng xem x´t. o a e a a o a e u e . . . . . . ’. A ˆ 1. MO D` U ´ e ` a ’ u e ’ Co. so. d˜. liˆu (CSDL) m`. v` c´c vˆ n dˆ liˆn quan d˜ nhiˆu t´c gia trong v` ngo`i o a a a ` e a e a a . . .´.c quan tˆm nghiˆn c´.u v` d˜ c´ nh˜.ng kˆt qua d´ng kˆ [1, 6 − 9, 11 − 15]. C´ nhiˆu c´ch ´ ` a ’ a nu o a e u a a o u e e’ o e ´ . ´ . ´ . ´ ’ a tiˆp cˆn kh´c nhau nhu. c´ch tiˆp cˆn theo l´ thuyˆt tˆp m`. [9, 13], theo l´ thuyˆt kha n˘ng e a a a e a y e a o y e . tu. [8, 12,
