• Annual Conference on Human and Language Technology
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• 2019.10a
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• pp.175-180
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• 2019

관계 추출은 문서에서 존재하는 트리플(주어, 관계어, 목적어)형식에 해당하는 단어를 추출하는 작업을 뜻한다. 본 논문에서는 멀티헤드 셀프 어텐션을 이용하여 트리플 중 주어나 목적어를 찾는 구조를 제안한다. 한국어 위키피디아와 DBpedia의 관계어를 단어 임베딩을 통해 벡터를 생성하고 입력한다. 초록과 관계어의 어텐션 이후 멀티 헤드 셀프 어텐선 구조를 통해 초록 중 관계어와 관련 있는 단어들의 가중치가 높아 진다. 멀티헤드 셀프 어텐션 과정을 반복하여 주요 단어들의 가중치가 계속해서 높아진다. 이를 입력으로 하여 정답이 될 단어의 시작과 끝을 선택한다. 제안 방법으로 직접 구축한 한국어 관계 추출 데이터셋을 대상으로 F1 0.7981의 성능을 보였다. 제안 방법은 관계어와 같이 단순한 정보만을 이용하고도 초록에서 적절한 정답 단어를 추출할 수 있음을 확인하였다. 관계어의 범위를 확장함으로서 나아가 육하원칙(5W1H)과 같은 이벤트의 추출에도 활용할 수 있을 것이다.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.10a
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• pp.523-524
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• 2016

본 논문에서는 링크드 데이터를 위한 대용량 RDF 저장 및 검색 시스템을 제안한다. 현재 링크드 데이터에 대한 핵심 이슈는 링크드 데이터의 효율적인 저장과 검색, 그리고 활용 애플리케이션 개발이다. 제안 시스템은 저장 관리자, 인덱스 구조, 그리고 질의 처리기로 구성되어 있다. 저장 관리자는 대용량 RDF 데이터를 처리하기 위해 그래프 데이터베이스에 데이터를 분산 저장하며, 인덱스 구조는 다차원 히스토그램, 보조 인덱싱, 그리고 그래프 인덱싱 기법이 구현된다. 질의 처리기는 SPARQL 또는 NoSQL 질의를 사용하여 질의 최적화 및 랭킹기법이 적용된 RDF 트리플 검색을 수행한다.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07b
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• pp.223-225
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• 2005

시맨틱 웹의 구현을 위한 수단으로 RDF 및 기타 기반 기술이 사용되고 있다. 이에 따라, 방대한 RDF 데이터의 효율적인 관리를 위한 연구들이 최근 활발하게 국내외에서 진행 중이다. 기존의 많은 연구들은 관계형 데이터베이스 시스템을 이용하여 트리플 형태의 RDF 데이터의 저장하는 방법을 제안하였다. 이러한 방법은 하나의 대규모 테이블상에 RDF 데이터를 저장하므로 데이터 관리측면에서 장점이 있으나 질의 처리 측면에서 볼 때 항상 테이블 전체를 접근해야 하므로 검색 성능이 저하될 수 있는 문제점이 있다. 본 논문에서는 질의 처리 성능을 높이기 위해 프로퍼티를 기반으로 RDF 데이터를 절러 개의 테이블로 분할 저장하는 기법을 제안한다.

• Proceedings of the Korean Society for Information Management Conference
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• 2013.08a
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• pp.113-117
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• 2013

팀 버너스 리에 의해 '시멘틱 웹'은 1998년 제안되었으나 현재 새롭게 생성되고 있는 데이터 혹은 자연어 형식의 데이터를 시멘틱 검색을 위해 활용하기에는 아직까지 온톨로지 데이터베이스가 따라가지 못하고 있다. 이를 위해 온톨로지 구축의 구성요소인 공리(axiom)를 공공을 위한 데이터로 개발하여 시멘틱 검색에 활용하는 개념적 모델을 제안한다. 공리 데이터베이스는 단일 도메인에서 벗어난 시멘틱 검색을 위한 데이터베이스로서 도메인 온톨로지 구축에 기본적인 요소들을 제공하고, 이용자들이 시멘틱 검색을 통해 보다 만족한 정보검색을 할 수 있도록 한다. 또한 온톨로지 데이터를 확보하기 위해 정보생산자로부터 사전어휘에 대한 온톨로지 트리플을 생성하는 실험을 하였다. 온톨로지 자동구축에 대한 연구와 개발이 활발하지만 보편적 시멘틱 검색을 위해 정보생산자와 정보관리자가 많은 부분 데이터를 생성하고 검증해야할 필요가 있다.

• The Journal of the Korea Contents Association
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• v.15 no.1
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• pp.9-23
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• 2015

In this paper, we propose a new RDF index scheme considering the characteristics of large scale RDF data to improve the query processing performance. The proposed index scheme creates a S-O index for subjects and objects since the subjects and objects of RDF triples are used redundantly. In order to reduce the total size of the index, it constructs a P index for the relatively small number of predicates in RDF triples separately. If a query contains the predicate, we first searches the P index since its size is relatively smaller compared to the S-O index. Otherwise, we first searches the S-O index. It is shown through performance evaluation that the proposed scheme outperforms the existing scheme in terms of the query processing time.

• Journal of KIISE
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• v.43 no.4
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• pp.450-459
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• 2016

Every year, RDFS data tends further toward scalability; hence, the manner of SPARQL processing needs to be changed for fast query. The query processing method of SPARQL has been studied using a scalable distributed processing framework. Current studies indicate that the query engine based on the scalable distributed processing framework i.e., Hadoop(MapReduce) is not suitable for real-time processing because of the repetitive tasks; in addition, it is difficult to construct a query engine based on an In-memory Distributed Query engine, because distributed structure on the low-level is required to be considered. In this paper, we proposed a method to construct a query engine for improving the speed of the query process with the mass triple data. The query engine processes the query of SPARQL using the SparkSQL, which is an In-memory based, distributed query processing framework. SparkSQL is a high-level distributed query engine that facilitates existing SQL statement. In order to process the SPARQL query, after generating the Algebra Tree using Jena, the Algebra Tree is required to be translated to Spark Algebra Tree for application in the Spark system, and construction of the system that generated the SparkSQL query. Furthermore, we proposed the design of triple property table based on DataFrame for more efficient query processing in the Spark system. Finally, we verified the validity through comparative evaluation with the query engine, which is the existing distributed processing framework.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.11 no.2
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• pp.183-195
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• 2016

Although we have faced substantial public interests on the issues of small-business, the lack of effective solutions corresponding to them should be worried. This paper introduces findings from the application of Triple Helix to counseling activities for small-business stores with diagnosing problems and suggesting alternatives. The findings of this paper are based on counseling projects conducted by Gyunggi Small-medium Business Corporation, universities in the region, and multiple small-business stores together from June to November in 2015. The application of Triple Helix was positive for increasing the effectiveness of counseling, and this key finding was obtained from action research cycles. It was also confirmed that cooperation from three different entities including company, university and government institute was beneficial in increasing problem identification capabilities by students and providing opportunities for testing knowledge and skills, which means Triple Helix application to small-business helps management education to be more practical. Contributions of this study supplies substantial insights to academic audience, and practitioners can learn positive effects of Triple Helix and potential issues for implementation in the context of small-business counseling.

• Journal of KIISE:Databases
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• v.33 no.5
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• pp.476-485
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• 2006

The Resource Description Framework(RDF), which emerged with the semantic web, is settling down as a standard for representing information about the resources in the World Wide Web Hence, a lot of research on storing and query processing RDF documents has been done and several RDF storage systems, such as Sesame and Jena, have been developed. But the research on updating RDF documents is still insufficient. When a RDF document is changed, data in the RDF triple store also needs to be updated. However, current RDF triple stores don't support incremental update. So updating can be peformed only by deleting the old version and then storing the new document. This updating method is very inefficient because RDF documents are steadily updated. Furthermore, it makes worse when several RDF documents are stored in the same database. In this paper, we propose an incremental update algorithm on RDF, documents in triple stores. We use a text matching technique for two versions of a RDF document and compensate for the text matching result to find the right target triples to be updated. We show that our approach efficiently update RDF documents through experiments with real-life RDF datasets.

• Journal of KIISE:Databases
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• v.36 no.6
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• pp.422-433
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• 2009

As an effort to secure Semantic Web, in this paper, we introduce an RDF access authorization model based on an ontology hierarchy and an RDF triple pattern. In addition, we apply the authorization model to RDF query validation for approved access authorizations. A subscribed SPARQL or RQL query, which has RDF triple patterns, can be denied or granted according to the corresponding access authorizations which have an RDF triple pattern. In order to efficiently perform the query validation process, we first analyze some primary authorization conflict conditions under RDF subsumption inference, and then we introduce an efficient query validation algorithm using the conflict conditions and Dewey graph labeling technique. Through experiments, we also show that the proposed validation algorithm provides a reasonable validation time and when data and authorizations increase it has scalability.

• Journal of the Korea Society of Computer and Information
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• v.14 no.11
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• pp.21-30
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• 2009

Semantic web uses ontology languages such as RDF, RDFS, and OWL to define the metadata on the web. There have been many researching efforts in the semantic web technologies based on an agent for extracting triple and relation about concept of ontology. But the extraction of relation and triple about the concept of ontology based on an agent ends up writing a limited query statement as characteristics of an agent. As for this, there is the less of flexibility when extracting triple and relation about the other concept of ontology. We are need a query tool for flexible information retrieval of ontology that is can access the standard ontology and can be used standard query language. In this paper, we propose a SPARQL query tool that is can access the OWL ontology via HTTP protocol and it can be used to make a query. Query result can be output to the soap message. These operations can be support the web service.