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Marine spatio-temporal process semantics and its applications-taking the El Nio Southern Oscilation process and Chinese rainfall anomaly as an example 被引量:4
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作者 XUE Cunjin DONG Qing XIE Jiong 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2012年第2期16-24,共9页
Spatio-temporal semantics based on "object views" or "event views" has few abilities to represent and model the continuity and gradual oceanic phenomena or objects, which seriously limits the specific marine appli... Spatio-temporal semantics based on "object views" or "event views" has few abilities to represent and model the continuity and gradual oceanic phenomena or objects, which seriously limits the specific marine applications and knowledge discovery and data mining, so this paper proposes a hierarchical abstraction semantics with "marine spatio-temporal process-life span phases-evolution sequences--state units" and process objects included by level with "marine process objects--phase objects--sequence object---state objects" with the oceanic process characteristics into the marine process semantics. In addition, this paper designs the storage and representation of marine process objects using the backus normal forms (BNF) and abstract data type (ADT). Base on E1 Nifio Southern Oscilation (ENSO) index and Chinese rain gauging station data, this paper also gives a case of study. The spatio-temporal analysis between ENSO process and Chinese rainfall anomalies shows that the marine spatio-temporal semantics not only can illustrate the spatial distribution of Chinese rainfall anomalies in different time scales at ENSO process, life span phases and state units, but also analyze the dynamic changes of Chinese rainfall anomalies in different life span phases or state units within ENSO evolution. 展开更多
关键词 marine process semantics hierarchical abstraction and inclusion by level ENSO proc ess rainfall anomalies
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Translational Semantics for a Conceptual Level Query Language
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作者 Hock C. Chan(Department of Information Systems and Computer Science, National University ofSingapore, Lower Kent Ridge Road, Singapore 0511) 《Journal of Computer Science & Technology》 SCIE EI CSCD 1995年第2期175-187,共13页
A conceptual level database language for the entity relationship (ER) modelimplicitly contains integrities basic to ER concepts and special retrieval seman-tics for inheritances of attributes and relationships. Prolog... A conceptual level database language for the entity relationship (ER) modelimplicitly contains integrities basic to ER concepts and special retrieval seman-tics for inheritances of attributes and relationships. Prolog, which belongs tothe logical and physical level, cannot be used as a foundation to directly definethe database language. It is shown how Prolog can be enhanced to under-stand the concepts of entities, relationships, attributes and is-a relationships.The enhanced Prolog is then used as a foundation to define the semantics of adatabase query language for the ER model. The three basic functions of modelspecification, updates and retrievas are defined. 展开更多
关键词 Conceptual level query language SEMANTICS logic entityrelationship model abstraction level ER calculus
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