• Journal of KIISE:Databases
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• v.41 no.4
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• pp.242-248
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• 2014

With the rapidly growing amount of information represented in RDF format, efficient querying of RDF graph has become a fundamental challenge. SPARQL is one of the most widely used query languages for retrieving information from RDF dataset. SPARQL is not only simple in its syntax but also powerful in representation of graph pattern queries. However, users need to make a lot of efforts to understand the ontology schema of a dataset in order to compose a relevant SPARQL query. In this paper, we propose a graph query formulation and processing scheme based on ontology schema information which can be obtained by summarizing RDF graph. In the context of the proposed querying scheme, a user can interactively formulate the graph queries on the graphic user interface without making efforts to understand the ontology schema and even without learning SPARQL syntax. The graph query formulated by a user is transformed into a set of class paths, which are stored in a relational database and used as the constraint for search space reduction when the relational database executes the graph search operation. By executing the LUBM query 2, 8, and 9 over LUBM (10,0), it is shown that the proposed querying scheme returns the complete result set.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.4
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• pp.139-144
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• 2009

The leveling of technical internet domain term with its aim to accumulate knowledge that machine can comprehend, which has been used widely in recent years. If stratify domain term weight, we believe that machine can manage and analyze in formation on its own using the ontology. In this paper, we propose an algorithm that allows us to extract properties of ontology weight from structured information already existing in web documents. In particular by stratification of the domain knowledge that is composed of property information, we were able to make the algorithm better and improve the quality of extraction results. In our experiments with 50 thousands targeted documents, we were able to extract property information with 94% confidence.

• Journal of Practical Engineering Education
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• v.15 no.2
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• pp.321-330
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• 2023

In this paper, we propose a method of automatically creating an ontology by extracting various relationships between terms necessary for constructing an ontology of a specific domain. The extracted relationship is constructed as an ontology by encoding it into an axiomatic set in the structure of the ontology. To solve efficiently, we represent the search space of the set as an integer programming problem, and we reduce the matrix by using a simple reduction that eliminates rules that are not very helpful for optimization. In conclusion, this paper proposes a way to generalize patterns using given data, reduce search space while maintaining useful patterns, and automatically generate efficient ontology using extracted relationships by applying algorithms composed of structured ontology.

• Proceedings of the Korean Information Science Society Conference
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• 2007.10c
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• pp.336-340
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• 2007

인터넷 쇼핑몰에서는 다양한 제품이 존재하며 제조회사마다 제품 정보를 표현하는 방식이 다르며, 같은 제품이라도 쇼핑몰마다 제품정보를 표현하는 방식이 다르다. 이런 환경에서 효율적인 제품정보의 수집과 제품정보의 검색이 필요하다. 쇼핑몰의 입장에서 다양한 회사의 다양한 제품 정보 수집 시 정보 수집의 정확성과 효율을 높이고 고객에게는 좀 더 유연한 검색과의 제공을 위한 상품 정보 시스템을 설계한다. 이를 위해서 첫째로, 제품정보에 대한 온톨로지를 구축하고, 온톨로지를 바탕으로 제품 정보를 추출하고, 데이터베이스화한다. 둘째로, 제품 정보에 대한 온톨로지를 이용하여 추론 기능을 이용한 검색 서비스를 적용한다. 본 논문은 MP3 제품에 대해 제품정보 수집과 검색을 위한 온톨로지 구축과 온톨로지를 이용한 정보추출, 추론 기술에 대해서 기술한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2005.05a
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• pp.465-468
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• 2005

본 논문에서는 OWL-S 서비스 온톨로지를 자동으로 생성하는 방법에 대한 연구결과를 제공한다. 자동생성을 위하여 UML 클래스 다이어그램 및 상태차트 다이어그램을 XMI 파일들로 변환한 후 원자 서비스 및 속성들에 대한 정보와 복합 서비스 조합에 대한 정보를 각각 추출한다. 추출된 정보는 UML 상태차트 다이어그램 구성 요소들과 OWL-S 복합 서비스를 위한 구조물들 사이의 매핑 규칙들을 통하여 XSLT 응용에서 OWL-S 서비스 모델 온톨로지를 자동으로 생성시키는데 사용된다. 생성된 온톨로지의 타당성 검증을 위해서 이용 가능한 여럿의 유효성 검사를 수행하였다. 우리의 방법론은 자동적, 효과적 및 일반적일 뿐만 아니라 서비스 온톨로지 생성자인 개발자들에게 매우 친숙한 환경에서 수행된다는 장점들을 가진다.

• Annual Conference on Human and Language Technology
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• 2007.10a
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• pp.140-144
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• 2007

시맨틱 웹 기술의 주축을 이루는 온톨로지의 구축시에 인스턴스를 생성하기 위하여 대상 문서를 구성하는 자연어 문장을 텍스트 마이닝 기술을 이용하여 트리플을 추출한다. 인스턴스를 생성할 때 보다 많은 정보를 추출하기 위해서 문장에 나타나는 상호참조 해결이 필요하다. 본 연구에서는 문서에서 많이 나타나는 명사구로 이루어진 대용어를 해석하기 위하여 언어 분석된 다양한 결과 정보를 이용한다. 본 연구에서는 계층적인 의미구조와 청킹을 이용한 규칙기반의 상호참조 해결 방법을 제안하고 실험을 통해 알고리즘의 정확도를 제시한다.

• Journal of Intelligence and Information Systems
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• v.19 no.1
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• pp.19-33
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• 2013

In this research, a proposed Dynamic Virtual Ontology using Tags (DyVOT) supports dynamic search of resources depending on user's requirements using tags from social web driven resources. It is general that the tags are defined by annotations of a series of described words by social users who usually tags social information resources such as web-page, images, u-tube, videos, etc. Therefore, tags are characterized and mirrored by information resources. Therefore, it is possible for tags as meta-data to match into some resources. Consequently, we can extract semantic relationships between tags owing to the dependency of relationships between tags as representatives of resources. However, to do this, there is limitation because there are allophonic synonym and homonym among tags that are usually marked by a series of words. Thus, research related to folksonomies using tags have been applied to classification of words by semantic-based allophonic synonym. In addition, some research are focusing on clustering and/or classification of resources by semantic-based relationships among tags. In spite of, there also is limitation of these research because these are focusing on semantic-based hyper/hypo relationships or clustering among tags without consideration of conceptual associative relationships between classified or clustered groups. It makes difficulty to effective searching resources depending on user requirements. In this research, the proposed DyVOT uses tags and constructs ontologyfor effective search. We assumed that tags are extracted from user requirements, which are used to construct multi sub-ontology as combinations of tags that are composed of a part of the tags or all. In addition, the proposed DyVOT constructs ontology which is based on hierarchical and associative relationships among tags for effective search of a solution. The ontology is composed of static- and dynamic-ontology. The static-ontology defines semantic-based hierarchical hyper/hypo relationships among tags as in (http://semanticcloud.sandra-siegel.de/) with a tree structure. From the static-ontology, the DyVOT extracts multi sub-ontology using multi sub-tag which are constructed by parts of tags. Finally, sub-ontology are constructed by hierarchy paths which contain the sub-tag. To create dynamic-ontology by the proposed DyVOT, it is necessary to define associative relationships among multi sub-ontology that are extracted from hierarchical relationships of static-ontology. The associative relationship is defined by shared resources between tags which are linked by multi sub-ontology. The association is measured by the degree of shared resources that are allocated into the tags of sub-ontology. If the value of association is larger than threshold value, then associative relationship among tags is newly created. The associative relationships are used to merge and construct new hierarchy the multi sub-ontology. To construct dynamic-ontology, it is essential to defined new class which is linked by two more sub-ontology, which is generated by merged tags which are highly associative by proving using shared resources. Thereby, the class is applied to generate new hierarchy with extracted multi sub-ontology to create a dynamic-ontology. The new class is settle down on the ontology. So, the newly created class needs to be belong to the dynamic-ontology. So, the class used to new hyper/hypo hierarchy relationship between the class and tags which are linked to multi sub-ontology. At last, DyVOT is developed by newly defined associative relationships which are extracted from hierarchical relationships among tags. Resources are matched into the DyVOT which narrows down search boundary and shrinks the search paths. Finally, we can create the DyVOT using the newly defined associative relationships. While static data catalog (Dean and Ghemawat, 2004; 2008) statically searches resources depending on user requirements, the proposed DyVOT dynamically searches resources using multi sub-ontology by parallel processing. In this light, the DyVOT supports improvement of correctness and agility of search and decreasing of search effort by reduction of search path.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.3
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• pp.221-225
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• 2009

Constructing an ontology using a mass corpus begins with an automatic semantic relation extraction. A general method regards words appearing between terms as patterns which are used to extract semantic relations. However, previous approaches consider only one sentence to extract a pattern, so they cannot extract semantic relations for terms in different sentences. This paper proposes a semantic relation extraction method using pairs of patterns sharing a term, where each pattern is extracted using one of the seed term pair satisfying the target relation. In our experiments, we achieved the accuracy 83.75% improving previous methods by 7.5% in is-${\alpha}$ relation and the accuracy 83.75% improved by 5% in part-of relation. We also present a possibility of improving the recall by the relative recall.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06c
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• pp.307-310
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• 2011

최근 멀티미디어 데이터의 급속한 증가는 그를 대상으로 하는 다양한 컴퓨팅 기술의 발전을 가져왔다. 이러한 기술이 인간과의 상호 작용에서 그 양적 범위와 질적 깊이를 더해감에 따라, 멀티미디어 데이터 특히 그 중 가장 대표적이라 할 수 있는 이미지 데이터를 의미적으로 이해할 수 있는 방법의 필요성이 대두되고 있다. 이미지의 의미를 이해하기 위해 저수준(low level)의 시각 정보만을 이용하는 경우 인간과의 상호 작용에서 의미 격차(conceptual gap) 문제가 발생할 수 있다. 이미지 객체의 시각 정보들을 가공해서 온톨로지(ontology)와 같은 형태의 지식 베이스(knowledge base)와 연동하여 보다 고수준의 의미를 부여하는 경우에는 해당 도메인을 벗어난 새로운 환경에 대해 적응력과 강인함이 떨어진다. 이러한 문제를 근본적으로 해결하기 위해서는 지식 베이스가 없는 상태에서 이미지 데이터의 형태로 주어진 대상 객체로부터 의미를 부여할 수 있는 정보들을 추출해, 구조적으로 지식 베이스를 형성해 나가고 이를 토대로 대상 이미지 객체의 의미를 이해할 수 있는 시스템이 필요하다. 본 논문에서는 발달 심리학 이론들을 바탕으로 시각과 관련된 인간의 생득적 능력을 찾고, 이를 기반으로 우선 주어진 이미지 객체로부터 의미 정보를 효과적으로 추출할 수 있는 방법을 제안한다.

• KIPS Transactions on Software and Data Engineering
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• v.7 no.8
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• pp.281-286
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• 2018

With recent increase in complexity and variety of information and massively available information, interest in and necessity of ontology has been on the rise as a method of extracting a meaningful search result from massive data. Although there have been proposed many methods of extracting the ontology from a given text of a natural language, the extraction based on most of the current methods is not consistent with the structure of the ontology. In this paper, we propose a method of automatically creating ontology by distinguishing a term needed for establishing the ontology from a text given in a specific domain and extracting various relationships between the terms based on the pattern-based method. To extract the relationship between the terms, there is proposed a method of reducing the size of a searching space by taking a matching set of patterns into account and connecting a join-set concept and a pattern array. The result is that this method reduces the size of the search space by 50-95% without removing any useful patterns from the search space.