Document type definition ( dtd ) should be defined before building urban geographic information system based on xml 要建立基于xml的城市地理信息系統,首先要定義它的文檔類型定義( documenttypedefinition , dtd ) 。
In order to manipulate the data among the databases each other it is required to comply with the uniform xml documents of document type definition ( dtd ) . there are three aspects are involved in this model mainly 數據庫之間的數據應遵守統一的文擋類型定義( adocumenttypedefinition , dtd )的xml文擋進行交換,以有利于互操作。
Dkow is capable of modeling and reasoning static domain knowledge , including domain structures , concepts and properties of the concepts , and the relations among concepts , etc . in order to apply the power of domain ontology to express the semantic information of web data , the author presents an algorithm named dtd generating from domain ontology ( dtdgdo ) that maps a given ontology to a document type definition ( dtd ) based on the transformation rules 作者提出了一種基于領域本體的web數據語義信息的表示方法,設計了dkow構建的形式化領域本體到相應dtd的生成算法dtdgdo 。作者在屬性定義方面增強了現有ecfgs方法對dtd模型的定義,設計了生成算法dtdgdo的三類轉換規則:重組規則、變換規則、基數規則。
In technique , the key is to implement the exchange of the mode of relational database and xml . that is mapping between them . the data structure is denoted by xml document type definition ( dtd ) and the content is denoted by xml document . so that keep consistent with each other in during of exchanging 在技術上,關鍵是實現關系數據庫與xml模式的互相轉換,即兩者之間的映射。數據庫存儲的元數據由xmldtd ( documenttypedefinition )表示,而數據信息由xml文檔表示。這樣,兩種模式在互相轉換的過程中就可達到一致性。