• Title/Summary/Keyword: Web Ontologies

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Ontology Versions Management Schemes using Change Set (변경 집합을 이용한 온톨로지 버전 관리 기법)

  • Yun, Hong-Won;Lee, Jung-Hwa;Kim, Jung-Won
    • Journal of Information Technology Applications and Management
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    • v.12 no.3
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    • pp.27-39
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    • 2005
  • The Semantic Web has increased the interest in ontologies recently Ontology is an essential component of the semantic web and continues to change and evolve. We consider versions management schemes in ontology. We study a set of changes based on domain changes, changes in conceptualization, metadata changes, and temporal dimension. Our change specification is represented by a set of changes. A set of changes consists of instance data change, structural change, and identifier change. In order to support a query in ontology versions, we consider temporal dimension includes valid time. Ontology versioning brings about massive amount of versions to be stored and maintained. We present the ontology versions management schemes that are 1) storing all the change sets, 2) storing the aggregation of change sets periodically, and 3) storing the aggregation of change sets using an adaptive criterion. We conduct a set of experiments to compare the performance of each versions management schemes. We present the experimental results for evaluating the performance of the three version management schemes from scheme 1 to scheme 3. Scheme 1 has the least storage usage. The average response time in Scheme 1 is extremely large, those of Scheme 3 is smaller than Scheme 2. Scheme 3 shows a good performance relatively.

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Applying OWL SameAs to an Ontology in the Semantic Web (시맨틱 웹 온톨로지에서의 OWL sameAs 적용)

  • Kang, In-Su;Jung, Han-Min;Lee, Seung-Woo;Kim, Pyung;Lee, Mi-Kyung;Sung, Won-Kyung
    • Journal of KIISE:Software and Applications
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    • v.34 no.4
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    • pp.359-367
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    • 2007
  • The ontology is the underlying knowledge base to create the semantic web. Prerequisites for the success of the semantic web include widespread uses/sharing/merging of ontologies. In addition, it is very crucial to secure the integrity of ontology instances such as instance-identifying/referring integrity, and attribute domain constraints. In terms of ensuring instance-identifying integrity, OWL provides owl:sameAs property which is used to connect two separate ontology instances in order to represent that the two instances are the same. Recent semantic web works, however, have not sufficiently investigated the issues one may face in applying owl:sameAs to real semantic web applications. This study introduces our experiences of sameAs in developing a semantic web service framework for a research domain.

The SemanticWeb Technology and its Applications (시맨틱웹 기술과 활용방안)

  • 오삼균
    • Journal of the Korean Society for information Management
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    • v.19 no.4
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    • pp.298-319
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    • 2002
  • The Semantic Web is a new technology that attempts to achieve effective retrieval, automation, integration, and reuse of web resources by constructing knowledge bases that are composed of machine-readable definitions and associations of resources that express the relationships among them. To have this kind of Semantic Web in place, it is necessary to have the following infrastructures: capability to assign unchangeable and unique identifier (URI) to each resource, adoption of XML namespace concept to prevent collision of element and attribute names defined by various institutions, widespread use of RDF to describe resources so that diverse metadata can be interoperable, use of RDF schema to define the meaning of metadata elements and the relationships among them, adoption of DAML+OIL that is built upon RDF(S) to increase reasoning capability and expressive power, and finally adoption of OWL that is built upon DAML+OIL by removing unnecessary constructors and adding new ones based on experience of using DAML+OIL. The purpose of this study is to describe the central concepts and technologies related to the Semantic Web and to discuss the benefits of metadata interoperability based on XML/RDF schemas and the potential applications of diverse ontologies.

Using the METHONTOLOGY Approach to a Graduation Screen Ontology Development: An Experiential Investigation of the METHONTOLOGY Framework

  • Park, Jin-Soo;Sung, Ki-Moon;Moon, Se-Won
    • Asia pacific journal of information systems
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    • v.20 no.2
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    • pp.125-155
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    • 2010
  • Ontologies have been adopted in various business and scientific communities as a key component of the Semantic Web. Despite the increasing importance of ontologies, ontology developers still perceive construction tasks as a challenge. A clearly defined and well-structured methodology can reduce the time required to develop an ontology and increase the probability of success of a project. However, no reliable knowledge-engineering methodology for ontology development currently exists; every methodology has been tailored toward the development of a particular ontology. In this study, we developed a Graduation Screen Ontology (GSO). The graduation screen domain was chosen for the several reasons. First, the graduation screen process is a complicated task requiring a complex reasoning process. Second, GSO may be reused for other universities because the graduation screen process is similar for most universities. Finally, GSO can be built within a given period because the size of the selected domain is reasonable. No standard ontology development methodology exists; thus, one of the existing ontology development methodologies had to be chosen. The most important considerations for selecting the ontology development methodology of GSO included whether it can be applied to a new domain; whether it covers a broader set of development tasks; and whether it gives sufficient explanation of each development task. We evaluated various ontology development methodologies based on the evaluation framework proposed by G$\acute{o}$mez-P$\acute{e}$rez et al. We concluded that METHONTOLOGY was the most applicable to the building of GSO for this study. METHONTOLOGY was derived from the experience of developing Chemical Ontology at the Polytechnic University of Madrid by Fern$\acute{a}$ndez-L$\acute{o}$pez et al. and is regarded as the most mature ontology development methodology. METHONTOLOGY describes a very detailed approach for building an ontology under a centralized development environment at the conceptual level. This methodology consists of three broad processes, with each process containing specific sub-processes: management (scheduling, control, and quality assurance); development (specification, conceptualization, formalization, implementation, and maintenance); and support process (knowledge acquisition, evaluation, documentation, configuration management, and integration). An ontology development language and ontology development tool for GSO construction also had to be selected. We adopted OWL-DL as the ontology development language. OWL was selected because of its computational quality of consistency in checking and classification, which is crucial in developing coherent and useful ontological models for very complex domains. In addition, Protege-OWL was chosen for an ontology development tool because it is supported by METHONTOLOGY and is widely used because of its platform-independent characteristics. Based on the GSO development experience of the researchers, some issues relating to the METHONTOLOGY, OWL-DL, and Prot$\acute{e}$g$\acute{e}$-OWL were identified. We focused on presenting drawbacks of METHONTOLOGY and discussing how each weakness could be addressed. First, METHONTOLOGY insists that domain experts who do not have ontology construction experience can easily build ontologies. However, it is still difficult for these domain experts to develop a sophisticated ontology, especially if they have insufficient background knowledge related to the ontology. Second, METHONTOLOGY does not include a development stage called the "feasibility study." This pre-development stage helps developers ensure not only that a planned ontology is necessary and sufficiently valuable to begin an ontology building project, but also to determine whether the project will be successful. Third, METHONTOLOGY excludes an explanation on the use and integration of existing ontologies. If an additional stage for considering reuse is introduced, developers might share benefits of reuse. Fourth, METHONTOLOGY fails to address the importance of collaboration. This methodology needs to explain the allocation of specific tasks to different developer groups, and how to combine these tasks once specific given jobs are completed. Fifth, METHONTOLOGY fails to suggest the methods and techniques applied in the conceptualization stage sufficiently. Introducing methods of concept extraction from multiple informal sources or methods of identifying relations may enhance the quality of ontologies. Sixth, METHONTOLOGY does not provide an evaluation process to confirm whether WebODE perfectly transforms a conceptual ontology into a formal ontology. It also does not guarantee whether the outcomes of the conceptualization stage are completely reflected in the implementation stage. Seventh, METHONTOLOGY needs to add criteria for user evaluation of the actual use of the constructed ontology under user environments. Eighth, although METHONTOLOGY allows continual knowledge acquisition while working on the ontology development process, consistent updates can be difficult for developers. Ninth, METHONTOLOGY demands that developers complete various documents during the conceptualization stage; thus, it can be considered a heavy methodology. Adopting an agile methodology will result in reinforcing active communication among developers and reducing the burden of documentation completion. Finally, this study concludes with contributions and practical implications. No previous research has addressed issues related to METHONTOLOGY from empirical experiences; this study is an initial attempt. In addition, several lessons learned from the development experience are discussed. This study also affords some insights for ontology methodology researchers who want to design a more advanced ontology development methodology.

A Study on the Thesaurus-based Ontology System for the Semantic Web (시소러스를 기반으로 한 온톨로지 시스템 구현에 관한 연구)

  • Jeong, Do-Heon;Kim, Tae-Su
    • Journal of the Korean Society for information Management
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    • v.20 no.3
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    • pp.155-175
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    • 2003
  • The purpose of the study was to construct a system based on the semantic web environment's ontology by utilizing the ontology schema derived from the facet-type Art and Architecture Thesaurus(AAT). The aforementioned ontology schema is based on the Web Ontology Language(OWL), which is being widely considered the standard ontology language for the W3C-centered semantic web environment. Also, the concepts were limited to terms within AAT'S Furniture Facet, and the system was tested using the Chair concept, which is a lower-level facet that has a diverse conceptual relationship and broad vocabulary base. The ontology system is capable of searching for concepts, while controlling the search results by always providing a 'Preferred term' for synonymous terms. In addition, the system provides the user with first, a relationship between the terms centered around the inquiry, and second, related terms along with their classification properties. Also, the system is presented as and application example of the ontology system that constructs a information system that intakes an Instance value and reproduces it into a RDF file. During this process, utilization of multiple ontologies was introduced, and the stored Instance value's meta-data elements were used.

Trends of Semantic Web Services and Technologies : Focusing on the Business Support (비즈니스를 지원하는 시멘틱 웹서비스와 기술의 동향)

  • Kim, Jin-Sung;Kwon, Soon-Jae
    • Journal of Intelligence and Information Systems
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    • v.16 no.4
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    • pp.113-130
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    • 2010
  • During the decades, considerable human interventions to comprehend the web information were increased continually. The successful expansion of the web services made it more complex and required more contributions of the users. Many researchers have tried to improve the comprehension ability of computers in supporting an intelligent web service. One reasonable approach is enriching the information with machine understandable semantics. They applied ontology design, intelligent reasoning and other logical representation schemes to design an infrastructure of the semantic web. For the features, the semantic web is considered as an intelligent access to understanding, transforming, storing, retrieving, and processing the information gathered from heterogeneous, distributed web resources. The goal of this study is firstly to explore the problems that restrict the applications of web services and the basic concepts, languages, and tools of the semantic web. Then we highlight some of the researches, solutions, and projects that have attempted to combine the semantic web and business support, and find out the pros and cons of the approaches. Through the study, we were able to know that the semantic web technology is trying to offer a new and higher level of web service to the online users. The services are overcoming the limitations of traditional web technologies/services. In traditional web services, too much human interventions were needed to seek and interpret the information. The semantic web service, however, is based on machine-understandable semantics and knowledge representation. Therefore, most of information processing activities will be executed by computers. The main elements required to develop a semantic web-based business support are business logics, ontologies, ontology languages, intelligent agents, applications, and etc. In using/managing the infrastructure of the semantic web services, software developers, service consumers, and service providers are the main representatives. Some researchers integrated those technologies, languages, tools, mechanisms, and applications into a semantic web services framework. Therefore, future directions of the semantic web-based business support should be start over from the infrastructure.

Implementation and Design of College Information Retrieval System Based On Ontology (온톨로지 기반 대학정보 검색 시스템의 설계 및 구현)

  • Park, Jong-Hoon;Kim, Chul-Won
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.2
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    • pp.296-301
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    • 2012
  • Currently, in order to develop an intelligent search engine to help users retrieve information effectively, many metodes have been used. The effective retrieval methods of these methods use ontology technology. Ontology technology is the core of the Semantic Web. In the Semantic Web, ontology technology can be used to retrieve related information through the inference engine more accurately and simply on the Semantic Web. In this paper, we implement and design college information retrieval based on ontology to retrieve college class, graduate school class and person class. We have collected the hierarchy structure about the College, graduate school and person informations, and we have used protege editor of the ontology developing tool to design some ontologies with the College informations collected. We also tested the designed ontology with the Inference Engine(Pellet) of protege editor, and implemented college information retrieval system using Inference Engine(Jena) for web services.

An Exploratory Study on Applications of Semantic Web through the Technical Limitation Factors of Knowledge Management Systems (지식경영시스템의 기술적 한계요인분석을 통한 시맨틱 웹의 적용에 관한 탐색적 연구)

  • Joo Jae-Hun;Jang Gil-Sang
    • The Journal of Society for e-Business Studies
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    • v.10 no.3
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    • pp.111-134
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    • 2005
  • Knowledge management is a core factor to achieve competitive advantage and improve the business performance. New information technology is also a core factor enabling the innovation of knowledge management. Semantic Web of which the goal is to realize machine-processable Web can't help affecting the knowledge management. Therefore, we empirically analyze the relationship between user's dissatisfaction and barriers or limitations of knowledge management and present methods allowing Semantic Web to overcome the limitations and to support knowledge management processes. Based on a questionnaire survey of 222 respondents, we found that the limitations of system qualities such as user inconvenience of knowledge management systems, search and integration limitations, and the limitations of knowledge qualities such as inappropriateness and untrust significantly affected the user dissatisfaction of knowledge management systems. Finally, we suggest a conceptual model of knowledge management systems of which components are resources, metadata, ontologies, and user & query layers.

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Semantic search of web documents using ontology (온톨로지를 이용한 웹문서의 시맨틱 검색)

  • Oh, Sung-Kyun;Kim, Byung-Gon
    • Journal of Digital Contents Society
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    • v.15 no.5
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    • pp.603-612
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    • 2014
  • To provide efficient and correct search results, ontology which use the structure of information, is considered as a main mechanism in the semantic web. Therefore, recent research in information retrieval and data construction have emphasized the use of ontologies as a data representation and search mechanism. In this paper, we propose a semantic search method using ontology to improve search ability in web environment. Ontology and knowledge base is used to represent semantic meaning of the data and provide related web documents and facts as results. Also, search result ranking mechanism is proposed. The mechanism use cardinality of the keyword in the contents and structural information of ontology. Experimental results with several query processing indicate that different coefficient value in the expression gives different results in sample ontology system and we propose appropriate values of the coefficient.

Dependency Label based Causing Inconsistency Axiom Detection for Ontology Debugging (온톨로지 디버깅을 위한 종속 부호 기반 비논리적 공리 탐지)

  • Kim, Je-Min;Park, Young-Tack
    • Journal of KIISE:Software and Applications
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    • v.35 no.12
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    • pp.764-773
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    • 2008
  • The web ontology language(OWL) has become a W3C recommendation to publish and share ontologies on the semantic web. In order to check the satisfiablity of concepts in OWL ontology, OWL reasoners have been introduced. But most reasoners simply report check results without providing a justification for any arbitrary entailment of unsatisfiable concept in OWL ontologies. In this paper, we propose dependency label based causing inconsistency axiom (CIA) detection for debugging unsatisfiable concepts in ontology. CIA is a set of axioms to occur unsatisfiable concepts. In order to detect CIA, we need to find axiom to cause inconsistency in ontology. If precise CIA is gave to ontology building tools, these ontology tools display CIA to debug unsatisfiable concepts as suitable presentation format. Our work focuses on two key aspects. First, when a inconsistency ontology is given, it detect axioms to occur unsatisfiable and identify the root of them. Second, when particular unsatisfiable concepts in an ontology are detected, it extracts them and presents to ontology designers. Therefore we introduce a tableau-based decision procedure and propose an improved method which is dependency label based causing inconsistency axiom detection. Our results are applicable to the very expressive logic SHOIN that is the basis of the Web Ontology Language.