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Nt1310 Unit 10 Utility List

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Definition 10: Utility-list.: [6] The utility-list of an itemset X in a database D is a set of tuples such that there is a tuple (tid; iutil; rutil) for each transaction Ttid containing X. The iutil is the utility of X in Ttid. i.e., u(X; Ttid). The rutil is remaining utility of element X in that transaction. Two known properties of HUIs are used in this algorithm[6]. Property 1: A High Utility itemset may contain items with negative external utilities. In our example, items A, B has an external utility of -4, -3. Property 2: A HUI must contain at least one item with a positive external utility. This is because if all items re negative utility, then there will not be any HUI.

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