面向模块重用的描述逻辑SHJF本地性规则研究

可重用本体模块的抽取是本体重用的一个关键环节。与传统工程应用中使用的基于本体层次的结构化方法抽取本体模块相比,使用逻辑的方法能充分利用本体提供的语义信息,抽取的本体模块更具完整性和正确性。在研究保守扩展的本体模块理论基础上,根据Grau B C提出的 SHOJQ 本地性规则,提出并证明了描述逻辑SHJF对应的语义本地性规则和句法本地性规则,为基于该规则抽取可重用本体模块提供了理论基础。     

A Rule-Based Object-Oriented OWL Reasoner

In this paper, we describe O-DEVICE, a memory-based knowledge-based system for reasoning and querying OWL ontologies by implementing RDF/OWL entailments in the form of production rules in order to apply the formal semantics of the language. Our approach is based on a transformation procedure of OWL ontologies into an object-oriented schema and the application of inference production rules over the generated objects in order to implement the various semantics of OWL. In order to enhance the performance of the system, we introduce a dynamic approach of generating production rules for ABOX reasoning and an incremental approach of loading ontologies. O-DEVICE is built over the CLIPS production rule system, using the object-oriented language COOL to model and handle ontology concepts and RDF resources. One of the contributions of our work is that we enable a well-known and efficient production rule system to handle OWL ontologies. We argue that although native OWL rule reasoners may process ontology information faster, they lack some of the key features that rule systems offer, such as the efficient manipulation of the information through complex rule programs. We present a comparison of our system with other OWL reasoners, showing that O-DEVICE can constitute a practical rule environment for ontology manipulation.     

Incremental Classification of Description Logics Ontologies

The development of ontologies involves continuous but relatively small modifications. However, existing ontology reasoners do not take advantage of the similarities between different versions of an ontology. In this paper, we propose a collection of techniques for incremental reasoning—that is, reasoning that reuses information obtained from previous versions of an ontology. We have applied our results to incremental classification of OWL ontologies and found significant improvement over regular classification time on a set of real-world ontologies.     

Extracting a justification for OWL ontologies by critical axioms

Extracting justifications for web ontology language (OWL) ontologies is an important mission in ontology engineering. In this paper, we focus on black-box techniques which are based on ontology reasoners. Through creating a recursive expansion procedure, all elements which are called critical axioms in the justification are explored one by one. In this detection procedure, an axiom selection function is used to avoid testing irrelevant axioms. In addition, an incremental reasoning procedure has been proposed in order to substitute series of standard reasoning tests w.r.t. satisfiability. It is implemented by employing a pseudo model to detect “obvious” satisfiability directly. The experimental results show that our proposed strategy for extracting justifications for OWL ontologies by adopting incremental expansion is superior to traditional Black-box methods in terms of efficiency and performance.     

Investigating ontology development for engineering design support

Ontologies are now in widespread use as a means of formalizing domain knowledge in a way that makes it accessible, shareable and reusable. Nevertheless, to many, the nature and use of ontologies are unfamiliar. This paper takes a practical approach - through the use of example - to clarifying what ontologies are and how they might be useful in an important and representative phase of the engineering design process, that of design requirement development and capture.The paper consists of two parts. In the first part ontologies and their use are discussed, and a methodology for developing ontologies is explored. In the second part, three very different types of ontology are developed in accordance with the methodology. Each of the ontologies captures a different conceptual facet of the engineering design domain, described at a quite different level of abstraction than the others. The process of developing ontologies is illustrated in a practical way and the application of these ontologies for supporting the capture of the engineering design requirement is described as a means of demonstrating the general potential of ontologies.     

A Flexible Ontology Reasoning Architecture for the Semantic Web

Knowledge-based systems in the semantic Web era can make use of the power of the semantic Web languages and technologies, in particular those related to ontologies. Recent research has shown that user-defined data types are very useful for semantic Web and ontology applications. The W3C semantic Web best practices and development working group has set up a task force to address this issue. Very recently, OWL-Eu and OWL-E, two decidable extensions of the W3C standard ontology language OWL DL, have been proposed to support customized data types and customized data type predicates, respectively. In this paper, we propose a flexible reasoning architecture for these two expressive semantic Web ontology languages and describe our prototype implementation of the reasoning architecture, based on the well-known FaCT DL reasoner, which witnesses the two key flexibility features of our proposed architecture: 1) It allows users to define their own data types and data type predicates based on built-in ones and 2) new data type reasoners can be added into the architecture without having to change the concept reasoner     

电子商务环境下产品本体构建技术研究

产品本体通过构建产品类层次及其属性描述为交易双方提供了对产品共享的通用的理解。针对目前电子商务中标准产品本体缺乏产品属性描述的问题，根据电子商务网站中产品信息多以表格形式组织和描述的特点，提出以联合国标准产品与服务分类代码（UNSPSC）为核心本体，结合表格处理技术的半自动产品本体构建方法。以Web表格为对象，对Web表格的识别、表格规范化、单元产品本体及全局产品本体建立进行了研究。这种半自动的本体建立方法可以解决电子商务中的产品信息模型因缺乏标准化的属性描述而产生不一致性，实现对核心产品本体的扩展和补充。     

How ontologies are made: Studying the hidden social dynamics behind collaborative ontology engineering projects

Traditionally, evaluation methods in the field of semantic technologies have focused on the end result of ontology engineering efforts, mainly, on evaluating ontologies and their corresponding qualities and characteristics. This focus has led to the development of a whole arsenal of ontology-evaluation techniques that investigate the quality of ontologies as a product. In this paper, we aim to shed light on the process of ontology engineering construction by introducing and applying a set of measures to analyze hidden social dynamics. We argue that especially for ontologies which are constructed collaboratively, understanding the social processes that have led to their construction is critical not only in understanding but consequently also in evaluating the ontologies. With the work presented in this paper, we aim to expose the texture of collaborative ontology engineering processes that is otherwise left invisible. Using historical change-log data, we unveil qualitative differences and commonalities between different collaborative ontology engineering projects. Explaining and understanding these differences will help us to better comprehend the role and importance of social factors in collaborative ontology engineering projects. We hope that our analysis will spur a new line of evaluation techniques that view ontologies not as the static result of deliberations among domain experts, but as a dynamic, collaborative and iterative process that needs to be understood, evaluated and managed in itself. We believe that advances in this direction would help our community to expand the existing arsenal of ontology evaluation techniques towards more holistic approaches.     

ComR: a combined OWL reasoner for ontology classification

Ontology classification, the problem of computing the subsumption hierarchies for classes (atomic concepts), is a core reasoning service provided by Web Ontology Language (OWL) reasoners. Although general-purpose OWL 2 reasoners employ sophisticated optimizations for classification, they are still not efficient owing to the high complexity of tableau algorithms for expressive ontologies. Profile-specific OWL 2 EL reasoners are efficient; however, they become incomplete even if the ontology contains only a small number of axioms that are outside the OWL 2 EL fragment. In this paper, we present a technique that combines an OWL 2 EL reasoner with an OWL 2 reasoner for ontology classification of expressive SROIQ. To optimize the workload, we propose a task decomposition strategy for identifying the minimal non-EL subontology that contains only necessary axioms to ensure completeness. During the ontology classification, the bulk of the workload is delegated to an efficient OWL 2 EL reasoner and only the minimal non- EL subontology is handled by a less efficient OWL 2 reasoner. The proposed approach is implemented in a prototype ComR and experimental results show that our approach offers a substantial speedup in ontology classification. For the wellknown ontology NCI, the classification time is reduced by 96.9% (resp. 83.7%) compared against the standard reasoner Pellet (resp. the modular reasoner MORe).     

Combining ontologies to automatically generate temporal perspectives of geospatial domains

This paper describes an approach for automatically combining geospatial and temporal ontologies such that a geospatial domain can be analyzed over multiple temporal granularities. Terms from a geospatial ontology are combined with terms from a temporal ontology to form cross products that provide an integrated spatiotemporal framework. This framework is multi-granular, highlighting elements from the geospatial ontology at different domain times. We show how pairs of ontologies represented in Protégé can be used as the input for deriving cross products and how the results of this technique can be used as a basis for querying and retrieving new perspectives on geospatial domains. Visualizations of cross product spaces highlight the geospatial–temporal combinations of terms as well as the different relations that link these terms and improve the understanding of the structure of the spatiotemporal framework. Methods for filtering terms from the cross products are also investigated in order to prune the resulting frameworks and remove irrelevant or unnecessary terms.     

Efficient retrieval of ontology fragments using an interval labeling scheme

Nowadays very large domain ontologies are being developed in life-science areas like Biomedicine, Agronomy, Astronomy, etc. Users and applications can benefit enormously from these ontologies in very different tasks, such as visualization, vocabulary homogenizing and data classification. However, due to their large size, they are often unmanageable for these applications. Instead, it is necessary to provide small and useful fragments of these ontologies so that the same tasks can be performed as if the whole ontology is being used. In this work we present a novel method for efficiently indexing and generating ontology fragments according to the user requirements. Moreover, the generated fragments preserve relevant inferences that can be made with the selected symbols in the original ontology. Such a method relies on an interval labeling scheme that efficiently manages the transitive relationships present in the ontologies. Additionally, we provide an interval’s algebra to compute some logical operations over the ontology concepts. We have evaluated the proposed method over several well-known biomedical ontologies. Results show very good performance and scalability, demonstrating the applicability of the proposed method in real scenarios.     

基于用例的领域业务服务本体建模

业务服务本体的作用是规范化描述领域业务活动及其之间关系,形成领域业务的基本知识体系。如何让涉众参与本体的设计,是目前联合本体工程研究的热点问题。通过将概念建模时常用的用例图与迭代式本体构建方法相结合,一方面使用领域本体建立规范的业务模型,另一方面基于用例,从用户视角优化本体模型。该建模方法有助于对领域业务的全面理解,所得到的本体模型可满足不同涉众需求。