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    政大機構典藏 > 理學院 > 資訊科學系 > 期刊論文 >  Item 140.119/69387
    Please use this identifier to cite or link to this item: http://nccur.lib.nccu.edu.tw/handle/140.119/69387

    Title: Refining imprecise data by integrity constraints
    Authors: 陳良弼
    Tseng,Frank S.C.;Chen,Arbee L.P.;Yang,Wei-Pang
    Contributors: 資科系
    Keywords: Imprecise data;partial values;refinement;referential integrity;functional dependency;multivalued dependency;multidatabase systems
    Date: 1993-12
    Issue Date: 2014-08-28 10:15:36 (UTC+8)
    Abstract: Uncertain data in databases were originally denoted as null values, which represent the meaning of ‘values unknown at present.” Null values were generalized into partial values, which correspond to a set of possible values, to provide a more powerful notion. In this paper, we derive some properties to refine partial values into more informative ones. In some cases, they can even be refined into definite values. Such a refinement is possible when there exist range constraint on attribute domains, or referential integrities, functional dependencies, or multivalued dependencies among attributes.Our work actually eliminates redundant elements in a partial value. By this process, we not only provide a more concise and informative answer to users, but also speedup the computation of queries issued afterward. Besides, it reduces the communication cost when imprecise data are requested to be transmitted from one site to another site in a distributed environment.
    Relation: Data & Knowledge Engineering,11(3),299-316
    Data Type: article
    Appears in Collections:[資訊科學系] 期刊論文

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