关系模式到XML模式的转换研究

本文首先研究了关系模式的特点,然后针对XML的树型结构特点,研究了基于语义约束的从关系模式到XML模式的转换,最后给出了从关系模式到XML模式转换的算法RTS。     

用于XML模式和DTD规范化设计的层次模式设计

XML模式和DTD(document type definition)规范化设计是给出一个很好地表示数据间依赖关系并消除了冗余的XML模式或DTD的集合.目前在这一方面开展的研究还不多,而且才刚起步.Provost提出将关系数据库理论应用于XML模式规范化设计的思想,这一思想还没有付诸实施.在Provost思想的基础上给出用于XML模式和DTD规范化设计的层次模式设计的算法.首先分析了基于Provost思想的层次分解;然后给出用于消除冗余模式的分解树设计算法;最后给出用于XML模式和DTD规范化设计的层次     

XML Schema中的面向对象思想

XML Schema是—种用来描述信息结构的机制,可用来定义XML文档的结构、数据类型等内容。为了在编写XML实例文档时更具灵活性,可考虑应用XMLSchema中的面向对象思想。     

生成具有层次特征XML模式的简化算法

XML已经广泛地应用于数据描述及数据交换,然而日常数据的大部分依旧存放在关系型数据库里,因此转换关系数据到XML文档的需求日益增长,如何高效生成用户满意的XML模式是其中的关键。NeT&CoT算法2是近年来提出的可根据给定的关系模式生成具有层次特征的XML的自动转换算法,然而它存在效率不高的问题。因此,该文在NeT&CoT算法的基础上提出了简化算法,通过引入四个简化性质,避免了费时的nest操作,提高了转换效率。     

用于XML模式和DTD设计的层次分解

对于XML模式和DTD规范化设计,现在开展的研究不多,而且才刚起步。W.Provost提出将关系数据库理论应用于XML模式规范化设计的思想,这一思想还没有付诸实施。该文给出表示XML模式和DTD的层次模式和用于XML模式和DTD规范化设计的层次分解过程,并对产生的层次模式进行分析。在算法产生的层次模式中,完全MVD和嵌入MVD的集合由给出的MVD集合导出。     

基于模式图的规范化XML模式设计

在给定关系模式的属性集及其函数依赖最小覆盖集的基础上,提出一种基于模式图的规范化XML模式设计方法。定义了模式图,在模式图中增加了Keys的描述信息,给出由函数依赖集构造模式图的算法。该模式图独立于具体的XML模式语言,经分析证明,所设计的模式满足XNF。     

Constructing ontologies by mining deep semantics from XML Schemas and XML instance documents

With the development of the Semantic Web and Artificial Intelligence techniques, ontology has become a very powerful way of representing not only knowledge but also their semantics. Therefore, how to construct ontologies from existing data sources has become an important research topic. In this paper, an approach for constructing ontologies by mining deep semantics from eXtensible Markup Language (XML) Schemas (including XML Schema 1.0 and XML Schema 1.1) and XML instance documents is proposed. Given an XML Schema and its corresponding XML instance document, 34 rules are first defined to mine deep semantics from the XML Schema. The mined semantics is formally stored in an intermediate conceptual model and then is used to generate an ontology at the conceptual level. Further, an ontology population approach at the instance level based on the XML instance document is proposed. Now, a complete ontology is formed. Also, some corresponding core algorithms are provided. Finally, a prototype system is implemented, which can automatically generate ontologies from XML Schemas and populate ontologies from XML instance documents. The paper also classifies and summarizes the existing work and makes a detailed comparison. Case studies on real XML data sets verify the effectiveness of the approach.     

Integration of XML Schemas at various “severity” levels

This paper presents a novel approach for the integration of a set of eXtensible Markup Language (XML) Schemas. The proposed approach is specialized for XML, almost automatic, semantic and “light”. Further, an original peculiarity is that it is parametric w.r.t. a “severity” level against which the integration task is performed. The paper describes the approach in all details, illustrates various theoretical results, presents the experiments we have performed for testing it and, finally, compares it with various related approaches already proposed in the literature.     

XML模式中隐式冗余不存在的充分条件

XML数据库模式规范化设计是产生一组相关联的、能很好地表示数据间依赖关系、而且消除了冗余的XML模式或DTD,以更好地进行信息检索.XML数据库模式中某些数据依赖是冗余存在的原因.因此在XML数据库模式中数据依赖与冗余的性质以及关联是其规范化设计要解决的关键问题.XML数据库模式的数据依赖包括属性间数据依赖和元素间的数据依赖.在以往的工作中,已经给出XML数据库模式中元素间的数据依赖及其所关联的显式冗余的有关性质,并基于此实现和验证相应的XML数据库模式规范化设计算法.分析XML数据库模式中属性间的数据依赖、元素间的数据依赖及其关联,定义XML数据库模式数据依赖及其相关联的隐式冗余,并论证XML数据库模式中隐式冗余不存在的充分条件.     

XML文档的范式

给出了 XML函数依赖、部分函数依赖和传递函数依赖的概念 ,然后据此提出了三种 XML范式 :1XNF、2 XNF和 3XNF.提出了 DTD无损联接分解的概念 ,给出了两个把 DTD无损联接地分解成 2 XNF和 3XNF的算法     

XML的规范化与范式

给出了XML间接函数依赖和传递函数依赖的概念,据此提出了以DTD为模式的XML文档的一种范式XMLNF,它可以消除XML文档中由于间接函数依赖和传递函数依赖所引起的数据冗余,给出了把DTD无损联接地分解成XMLNF的规范化方法.     

On the minimization of XML Schemas and tree automata for unranked trees

Automata for unranked trees form a foundation for XML Schemas, querying and pattern languages. We study the problem of efficiently minimizing such automata. First, we study unranked tree automata that are standard in database theory, assuming bottom-up determinism and that horizontal recursion is represented by deterministic finite automata. We show that minimal automata in that class are not unique and that minimization is np-complete. Second, we study more recent automata classes that do allow for polynomial time minimization. Among those, we show that bottom-up deterministic stepwise tree automata yield the most succinct representations. Third, we investigate abstractions of XML schema languages. In particular, we show that the class of one-pass preorder typeable schemas allows for polynomial time minimization and unique minimal models.     

Semantic and structural similarities between XML Schemas for integration of ubiquitous healthcare data

Currently, a lot of recent electronic health records are based on XML documents. In order to integrate these heterogeneous XML medical documents efficiently, studies on finding structure and semantic similarity between XML Schemas have been exploited. The main problem is how to harvest the most appropriate relatedness to combine two schemas as a global XML Schema for reusing and referring purposes. In this paper, we propose the novel resemblance measure that concurrently considers both structural and semantic information of two specific healthcare XML Schemas. Specifically, we introduce new metrics to compute the datatype and cardinality constraint similarities, which improve the quality of the semantic assessment. On the basis of the similarity between each element pair, we put forward an algorithm to calculate the similarity between XML Schema trees. Experimental results lead to the conclusion that our methodology provides better similarity values than the others with regard to the accuracy of semantic and structure similarities.     

Relax NG技术特点及其相对于DTDs和W3C XML Schemas的优越性

根据作者在使用XML工具从事应用软件开发工作中的体会,分析了一种新的XML模式语言——RELAXNG的特点和优越性;并通过实例,将它在语义模型、属性和元素的一致性、数据类型、信息集增加等方面与DTDs和W3C XML Schemas技术进行了比较。     

Algorithm and Tools for Constructing Canonical Forms of Linear Semi-Algebraic Formulas

The results of testing formula simplification tools are presented in the first part of this paper. In the second part, an algorithm for constructing canonical forms of linear semi-algebraic formulas is described. The main result of the study is the definition of the canonical form of a linear semi-algebraic formula that has the property of uniqueness and other useful properties. An algorithm for constructing such a formula is described.     

Integrating E-Business XML Business Forms and Rule-Based Agent Technologies

This study investigates the role of extensible mark-up language (XML) business forms and agent-based computing to support negotiation, management and implementation of inter-organization business processes. We explore recently proposed standards for representing artificial agent exchanges through rule-based inference. An XML representational syntax for standard business forms is developed and applied to augment rule-based agents. A prototype investigates ways to combine knowledge-based agents and business forms to assist business and customers in Web-based conference registration. The implementation helps guide customer decisions and the combination of business forms and rules promotes understandability, testability and adaptability of the registration system.     

Heuristic Algorithms for Determination of Canonical Forms and Grammatical Characteristics of Words

Algorithms are developed that determine canonic forms and grammar categories from individual words and the vocabulary of a text. Algorithms are proved to be highly efficient. The accuracy of determination directly depends on the length of the text.     

Canonical Forms and Algorithms for Steiner Trees in Uniform Orientation Metrics

We present some fundamental structural properties for minimum length networks (known as Steiner minimum trees) interconnecting a given set of points in an environment in which edge segments are restricted to λ uniformly oriented directions. We show that the edge segments of any full component of such a tree contain a total of at most four directions if λ is not a multiple of 3, or six directions if λ is a multiple of 3. This result allows us to develop useful canonical forms for these full components. The structural properties of these Steiner minimum trees are then used to resolve an important open problem in the area: does there exist a polynomial time algorithm for constructing a Steiner minimum tree if the topology of the tree is known? We obtain a simple linear time algorithm for constructing a Steiner minimum tree for any given set of points and a given Steiner topology.