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Handling Uncertain Information in Vague Databases
PhD Thesis Proposal Defence Title: "Handling Uncertain Information in Vague Databases" by Mr. An LU Abstract: The relational data model has been extensively studied for over three decades in handling crispy data. It is well known that fuzzy database models based on the fuzzy set theory by have been introduced to handle uncertain data, which exist in many real life applications. Essentially, in a fuzzy set (FS) each element is associated with a point-value selected from the unit interval [0,1], which is termed the grade of membership in the set. A vague set (VS) is a further generalization of an FS. Instead of using point-based membership as in FSs, interval-based member- ship is used in a VS. The interval-based membership in VSs is more expressive in capturing vagueness of data. Thus, we extend relational data model by vague set theory to handle uncertain information. In our initial work, we utilize functional dependencies (FDs), which are the most fundamental integrity constraints that arise in practice in relational databases, to maintain the consistency of a vague database by adopting the vague chase (VChase) procedure. We also propose the concept of vague association rule (VAR). VARs address a limitation in the traditional association rule (AR) mining problem, which ignores the hesitation information of items in transactions. For example, in many online shopping applications, the items that are put into the basket but not checked out carry hesitation information. All the above work indicates that the vague set model is an effective means to capture and process uncertain information involved in applications. In this proposal, we also discuss several on-going plans on handling uncertain information in vague databases. Date: Wednesday, 3 September 2008 Time: 10:30a.m.-12:30p.m. Venue: Room 4480 lifts 25-26 Committee Members: Dr. Wilfred Ng (Supervisor) Prof. Qiang Yang (Chairperson) Dr. Ke Yi Dr. Nevin Zhang **** ALL are Welcome ****