Fuzzy databases

The objective of the thesis: Mining association rules with time-interval between events in temporal quantitative databases called fuzzy time-interval association rules; mining sequential patterns with time-interval between events in temporal quantitative sequential databases called fuzzy sequential patterns with fuzzy time intervals; mining common sequential rules with time-interval between events in temporal quantitative sequential databases called fuzzy common sequential rules with fuzzy time intervals.

27p beloveinhouse01 15-08-2021 15 4   Download

In this paper, we present a definition of fuzzy multivalued dependencies in fuzzy databases with linguistic data based on similarity relation which is built by partitioning the domain of attribute values corresponding to an appropriate hedge algebra. Some properties of fuzzy multivalued dependencies are studied. Finally, the set of inference rules is shown to be sound and complete for a relation scheme class when it satisfies some specified conditions.

15p binhminhmuatrenngondoithonggio 09-06-2017 52 1   Download

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.

12p binhminhmuatrenngondoithonggio 09-06-2017 27 2   Download

In this paper, we introduced a method to approximate data on domain of fuzzy attributes in relation of fuzzy databases based hedge algebra. Because, domain of fuzzy attributes can except values are number, linguistic values, thus we have to effect and simply on method to approximate data.

12p binhminhmuatrenngondoithonggio 09-06-2017 39 4   Download

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.

15p binhminhmuatrenngondoithonggio 09-06-2017 34 3   Download

In this paper, we propose a new approach to overcome the limitations of the approach that is based on hedge algebra structure for building fuzzy object-oriented databases model. Some operators fuzzy object-oriented relation algebra are proposed corresponding with the model. Finally,we propose a method of fuzzy object-oriented query processing flexibly.

13p binhminhmuatrenngondoithonggio 09-06-2017 40 3   Download

Bài báo tập trung nghiên cứu phụ thuộc mờ giữa các thuộc tính và giữa thuộc tính với phương thức trong một lớp đối tượng mờ dựa trên xấp xỉ ngữ nghĩa theo cách tiếp cận đại số gia tử (ĐSGT). Tương tự như trong cơ sở dữ liệu (CSDL) quan hệ rõ/mờ, bài báo đưa ra các định nghĩa phụ thuộc thuộc tính mờ và phụ thuộc phương thức mờ.

13p dieutringuyen 07-06-2017 44 2   Download

This paper proposes a method for mining fuzzy association rules using compressed database. We also use the approach of Hedge Algebra (HA) to build the membership function for attributes instead of using the normal way of fuzzy set theory. This approach allows us to explore fuzzy association rules through a relatively simple algorithm which is faster in terms of time, but it still brings association rules which are as good as the classical algorithms for mining association rules.

12p dieutringuyen 07-06-2017 41 3   Download

Trong bài báo này, chúng tôi tiếp tục nghiên cứu một số dạng chuẩn mờ. Các khái niệm khóa mức K, siêu khóa mức K và dạng chuẩn F1NF, KF2NF, KF3NF, KFBCNF trong cơ sở dữ liệu mờ chứa dữ liệu ngôn ngữ được định nghĩa. Phép tách một lược đồ cơ sở dữ liệu về dạng chuẩn KF3NF bảo toàn các phụ thuộc hàm mờ cũng như tách về dạng chuẩn KFBCNF bảo toàn thông tin được quan tâm nghiên cứu.

10p dieutringuyen 07-06-2017 67 6   Download

In this paper, we describe a hedge algebras based approach to modelling uncertainty in fuzzy object-oriented databases. Membership value reflects the degree of fuzziness existing in the data values and uncertainty is extended to the class definition level and is the basis for the determination of the membership of an object in a class.

13p dieutringuyen 07-06-2017 52 2   Download