dc.contributor | 資科系 | en_US |
dc.creator (作者) | 陳良弼 | zh_TW |
dc.creator (作者) | Tseng,Frank S.C.;Chen,Arbee L.P.;Yang,Wei-Pang | en_US |
dc.date (日期) | 1993-12 | en_US |
dc.date.accessioned | 28-八月-2014 10:15:36 (UTC+8) | - |
dc.date.available | 28-八月-2014 10:15:36 (UTC+8) | - |
dc.date.issued (上傳時間) | 28-八月-2014 10:15:36 (UTC+8) | - |
dc.identifier.uri (URI) | http://nccur.lib.nccu.edu.tw/handle/140.119/69387 | - |
dc.description.abstract (摘要) | 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. | en_US |
dc.format.extent | 129 bytes | - |
dc.format.mimetype | text/html | - |
dc.language.iso | en_US | - |
dc.relation (關聯) | Data & Knowledge Engineering,11(3),299-316 | en_US |
dc.subject (關鍵詞) | Imprecise data; partial values; refinement; referential integrity; functional dependency; multivalued dependency; multidatabase systems | en_US |
dc.title (題名) | Refining imprecise data by integrity constraints | en_US |
dc.type (資料類型) | article | en |