Automatic extraction of OWL ontologies from UML class diagrams: a semantics-preserving approach

Full implementation of the Semantic Web requires widespread availability of OWL ontologies. Manual ontology development using current OWL editors remains a tedious and cumbersome task that requires significant understanding of the new ontology language and can easily result in a knowledge acquisition bottleneck. On the other hand, abundant domain knowledge has been specified by existing database schemata such as UML class diagrams. Thus developing an automatic tool for extracting OWL ontologies from existing UML class diagrams is helpful to Web ontology development. In this paper we propose an automatic, semantics-preserving approach for extracting OWL ontologies from existing UML class diagrams. This approach establishes a precise conceptual correspondence between UML and OWL through a semantics-preserving schema translation algorithm. The experiments with our implemented prototype tool, UML2OWL, show that the proposed approach is effective and a fully automatic ontology extraction is achievable. The proposed approach and tool will facilitate the development of Web ontologies and the realization of semantic interoperations between existing Web database applications and the Semantic Web.     

面向Web信息资源的领域本体模型自动构建机制的研究

领域本体的构建是本体工程研究与应用的重要内容。面向网络Web信息资源,获取领域相关文本信息,通过对文本的概念分析,构建领域本体模型。提出一套本体自动构建机制,该本体构建基于数据挖掘和机器学习技术,内容主要包括基于贝叶斯(Bayes)分类原理;提出多个分类器方式的概念分类过程和算法;提出概念关联分析和概念自学习算法,建立本体原型;提出面向OWL本体模型的转换映射机制,构建基于OWL的本体模型。此外,还提出了从网络资源获取、领域本体建模到本体实施应用的一套完整的本体构建和应用实施的解决方案。     

Comparing relationships in conceptual modeling: mapping to semantic classifications

Much of the research that deals with understanding the real world and representing it in a conceptual model uses some form of the entity-relationship model as a means of representation. This research proposes an ontology for classifying relationship verb phrases based upon the domain and context of the application within which the relationship appears. The classification categories to which the verb phrases are mapped were developed based upon prior research in databases, ontologies, and linguistics. The usefulness of the ontology for comparing relationships when used in conjunction with an entity ontology is discussed. Together, these ontologies can be effective in comparing two conceptual database designs for integration and validation. Empirical testing of the ontology on a number of relationships from different application domains and contexts illustrates the usefulness of the research.     

Agent-based ontology mapping and integration towards interoperability

Abstract: Interoperability is an important issue in ontology research. In this paper, a novel agent-based framework for managing ontologies in a dynamic environment is developed. The framework has several key characteristics such as flexibility and extensibility that differentiate this research from others. Based on the proposed framework, ontology mapping and integration are investigated. It is believed that inter-ontology processes like ontology mapping with logical semantics are foundations of ontology-based applications. Accordingly, several types of semantic relations are proposed and corresponding mapping mechanisms are developed. Based on mapping results, ontology integration is developed to provide abstract views for participating organizations in the presence of a variety of ontologies. A prototype is built to demonstrate the design and functionalities and is applied to beer ontologies. The prototype shows that the framework is not only flexible but also practical. All agents derived from the framework exhibit their behaviours as expected.     

A methodology for constructing of philosophy ontology based on philosophical texts

An ontology is a crucial factor for the success of the Semantic Web and other knowledge-based systems in terms of share and reuse of domain knowledge. However, there are a few concrete ontologies within actual knowledge domains including learning domains. In this paper, we develop an ontology which is an explicit formal specification of concepts and semantic relations among them in philosophy. We call it a philosophy ontology. Our philosophy is a formal specification of philosophical knowledge including knowledge of contents of classical texts of philosophy. We propose a methodology, which consists of detailed guidelines and templates, for constructing text-based ontology. Our methodology consists of 3 major steps and 14 minor steps. To implement the philosophy ontology, we develop an ontology management system based on Topic Maps. Our system includes a semi-automatic translator for creating Topic Map documents from the output of conceptualization steps and other tools to construct, store, retrieve ontologies based on Topic Maps. Our methodology and tools can be applied to other learning domain ontologies, such as history, literature, arts, and music.     

Image retrieval with a multi-modality ontology

Ontologies represent domain concepts and relations in a form of semantic network. Many research works use ontologies in the information matchmaking and retrieval. This trend is further accelerated by the convergence of various information sources supported by ontologies. In this paper, we propose a novel multi-modality ontology model that integrates both the low-level image features and the high-level text information to represent image contents for image retrieval. By embedding this ontology into an image retrieval system, we are able to realize intelligent image retrieval with high precision. Moreover, benefiting from the soft-coded ontology model, this system has good flexibility and can be easily extended to the larger domains. Currently, our experiment is conducted on the animal domain canine. An ontology has been built based on the low-level features and the domain knowledge of canine. A prototype retrieval system is set up to assess the performance. We compare our experiment results with traditional text-based image search engine and prove the advantages of our approach.     

Ontology Evolution: Not the Same as Schema Evolution

As ontology development becomes a more ubiquitous and collaborative process, ontology versioning and evolution becomes an important area of ontology research. The many similarities between database-schema evolution and ontology evolution will allow us to build on the extensive research in schema evolution. However, there are also important differences between database schemas and ontologies. The differences stem from different usage paradigms, the presence of explicit semantics and different knowledge models. A lot of problems that existed only in theory in database research come to the forefront as practical problems in ontology evolution. These differences have important implications for the development of ontology-evolution frameworks: The traditional distinction between versioning and evolution is not applicable to ontologies. There are several dimensions along which compatibility between versions must be considered. The set of change operations for ontologies is different. We must develop automatic techniques for finding similarities and differences between versions.     

Methodology and intermediate layer for the automatic creation of ontology instances stored in relational databases

In this paper, we introduce our solution for mapping local ontologies to relational and object‐oriented representations. This solution is part of the GeoNis framework for the interoperability of geo‐information systems applications in a local community environment. The GeoNis framework is based on a hybrid ontology approach for data integration. Therefore, a very important subject in our research on semantic data integration is the creation of mapping between a spatial information source and its local ontology. We developed the OWL2RDB mapping language to create an intermediate layer between a relational database and the OWL ontology. This intermediate layer contains rules (expressed in the OWL2RDB language) for mapping between the structural elements of a relational database and the concepts of OWL ontologies. We also present a system that uses the OWL2RDB intermediate layer to create classes that can handle ontology instances stored in relational databases. We have developed a prototype for a tool that uses this proposed approach for the automatic generation of translator/wrapper components in the GeoNis interoperability environment. Copyright © 2012 John Wiley & Sons, Ltd.     

关系数据库模式和本体间映射的研究综述

关系数据库模式和本体问映射是语义网研究中的一个重要问题.首先,给出关系数据库模式和本体间映射的形式化定义,并从建模思想和应用场景两个方面分析问题的难点.根据3个不同角度,即模型转换的途径、映射策略的适用范围以及映射结果的表达形式,调研当前存在的多种解决途径.在此基础上,进一步介绍并比较6个具有代表性的关系数据库模式和本体间映射的工具.最后,讨论存在的挑战,并指出未来可能的研究方向.     

从ER模式到OWL DL本体的语义保持的翻译

提出了一种从ER模式到OWL DL本体的语义保持的翻译方法.该方法在形式化表示ER模式的基础上,建立ER模式和OWL DL本体之间精确的概念对应,通过一个翻译算法按照一组预定义的映射规则实现模式翻译.理论分析表明,该方法是语义保持的和有效的;算法实现和案例研究进一步证实,完全自动的机器翻译是可实现的.该文方法是原创性的,为Web本体的开发以及数据库和语义Web之间语义互操作的实现开辟了一条有效途径.