中文摘要：

DTDs（或XML Schema）的一致性是XML研究中的一个重要课题.一个DTD是一致的当且仅当存在有效的XML文档遵循这个DTD.然而一个一致性成立的DTD仍有可能存在一致性不成立的不合理子结构,同一致性不成立的DTDs一样,DTDs中一致性不成立的子结构同样应该尽量避免.为解决这一问题,对“元素在DTD中的一致性”、“DTDs完全一致性”等概念进行了定义和分析,并给出了一种新的DTDs完全一致性判断算法,该算法的最坏时间复杂度是O（n）,具有较高的效率.

英文摘要：

A document type definition （DTD） describes the structure of a set of similar XML documents and serves as the schema for XML documents. Consistency of DTDs is an important topic in XML research. A DTD is consistent if and only if there is some valid XML document conforming to the DTD, while a DTD is inconsistent if there is no XML document conforming to it. Inconsistent DTDs are of no use and should be avoided as well as possible. However, a consistent DTD may have inconsistent sub-structures that no valid XML data could conform to. This kind of DTDs should be avoided as well as inconsistent DTDs. In order to solve this problem, a new notion of ＂element consistency in a DTD＂ is put forward in this paper. Based on ＂element consistency in a DTD＂, notion of ＂absolute consistent DTDs＂ , which means consistent DTDs with no inconsistent sub-structures, is discussed. Furthermore, a new DTDs absolute consistency checking algorithm, with which a DTD can be determined absolute consistent or not consistent quickly, is also offered. The worst time complexity of the new DTDs absolute consistency checking algorithm is O（n）.