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
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
基金The National Basic Research Program of China under contract No.2009CB723903the National Natural Science Foundation of China under contract Nos 40901194 and 40801162+2 种基金the Director Foundation of CEODECASunder contract No.Y2ZZ06101B
文摘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.
文摘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.