• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.74-78
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• 2009

Efficient reasoning has become important for improving the performance of ontology systems as the size of ontology grows. In this paper, we introduce a method that efficiently performs reasoning of RDFS entailment rules (i.e., rdfs7 and rdfs9 rules) and OWL inverse rule using views in the DBMS-based triple sotre. Reasoning is performed by replacing reasoning rules with the corresponding view definition and storing RDF triples into the structured triple tables. When processing queries, the views is referred instead of original tables. In this way, we can reduce the time needed for reasoning and also obtain the space-efficiency of the triple store.

• Journal of KIISE:Computer Systems and Theory
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• v.34 no.10
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• pp.474-492
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• 2007

In the protein interaction network, there are many meaningful functional modules, each involving several protein interactions to perform discrete functions. Pathways and protein complexes are the examples of the functional modules. In this paper, we propose a new method for detecting the functional modules based on concept. A conceptual functional module, briefly concept module is introduced to match the modules taking them as its instances. It is defined by the corresponding rule composed of triples and operators between the triples. The triples represent conceptual relations reifying the protein interactions of a module, and the operators specify the structure of the module with the relations. Furthermore, users can define a composite concept module by the counterpart rule which, in turn, is defined in terms of the predefined rules. The concept module makes it possible to detect functional modules that are conceptually similar as well as structurally identical to users' queries. The rules are managed in the XML format so that they can be easily applied to other networks of different species. In this paper, we also provide a visualized environment for intuitionally describing complexly structured rules.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06c
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• pp.78-80
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• 2012

개체 관계(ER) 모델과 확장 개체 관계(EER) 모델은 개념적 데이터베이스 설계분야에서 가장 많이 사용되는 모델이다. 확장 개체 관계 모델은 여전히 객체지향 데이터베이스를 처리하는데 강력하나 최신 객체관계 데이터베이스와 UML과 같은 새로운 데이터베이스 모델링을 처리하기에는 부족함이 많다. 따라서 본 논문에서는 이러한 객체 관계 데이터베이스를 지원하기 위한 확장 개체 관계 기반의 변환 방법을 제안한다. 변환 규칙은 트리플 그래프 문법을 사용하여 정의하고 MOFRON TGG 에디터를 이용하여 표현한다. 트리플 그래프 문법 규칙에 따라 본 제안 방법은 자동 ORDB 개발 프레임워크에 적용할 수 있다.

• Journal of KIISE
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• v.45 no.3
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• pp.224-233
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• 2018

Recently, there are many of studies on SWRL reasoning engine based on user-defined rules in a distributed environment using a large-scale ontology. Unlike the schema based axiom rules, efficient inference orders cannot be defined in SWRL rules. There is also a large volumet of network shuffled data produced by unnecessary iterative processes. To solve these problems, in this study, we propose a method that uses Map-Reduce algorithm and distributed in-memory framework to deduce multiple rules simultaneously and minimizes the volume data shuffling occurring between distributed machines in the cluster. For the experiment, we use WiseKB ontology composed of 200 million triples and 36 user-defined rules. We found that the proposed reasoner makes inferences in 16 minutes and is 2.7 times faster than previous reasoning systems that used LUBM benchmark dataset.

• Journal of KIISE
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• v.42 no.10
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• pp.1195-1206
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• 2015

For the management of a knowledge system, systems that automatically infer and manage scalable knowledge are required. Most of these systems use ontologies in order to exchange knowledge between machines and infer new knowledge. Therefore, approaches are needed that infer new knowledge for scalable ontology. In this paper, we propose an approach to perform rule based reasoning for scalable SHIF ontologies in a spark framework which works similarly to MapReduce in distributed memories on a cluster. For performing efficient reasoning in distributed memories, we focus on three areas. First, we define a data structure for splitting scalable ontology triples into small sets according to each reasoning rule and loading these triple sets in distributed memories. Second, a rule execution order and iteration conditions based on dependencies and correlations among the SHIF rules are defined. Finally, we explain the operations that are adapted to execute the rules, and these operations are based on reasoning algorithms. In order to evaluate the suggested methods in this paper, we perform an experiment with WebPie, which is a representative ontology reasoner based on a cluster using the LUBM set, which is formal data used to evaluate ontology inference and search speed. Consequently, the proposed approach shows that the throughput is improved by 28,400% (157k/sec) from WebPie(553/sec) with LUBM.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10b
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• pp.284-288
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• 2006

본 논문은 시맨틱 웹 기술이 융합된 지식기반 정보유통 플랫폼(OntoFrame-K$^{(R)}$)의 추론 서비스 시스템 (OntoThink-K$^{(R)}$)에서 이용되는 Persistent Model인 DBMS기반의 온톨로지 확장 모델에 대해 설명하고자 한다. OntoFrame-K$^{(R)}$는 대용량의 지식 데이터를 다루기 때문에 기존에 개발된 온톨로지 추론 엔진을 이용할 경우 많은 한계점을 가지게 된다. 따라서 우리는 대용량의 지식 데이터를 안정적으로 처리할 수 있으며 추론의 신뢰성과 정합성을 가지는 온톨로지 확장 모델을 설계, 구현하였다. 본 모듈은 OWL과 인스턴스 데이터를 트리플 형태로 변환하여 입력 받은 후, 온톨로지 스키마 규칙과 사용자 정의 규칙을 이용한 정방향 추론 방법으로 추론 서비스에서 필요한 지식데이터들을 생성하는 역할을 한다. 본 모델은 DBMS를 이용하여 대용량의 지식 데이터를 저장할 수 있으며, 추론 규칙에 따른 정방향 추론을 통해 지식 모델을 확장하기 때문에 데이터의 정합성이 보장된다.

• Annual Conference on Human and Language Technology
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• 2015.10a
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• pp.41-45
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• 2015

무제한 정보추출은 주로 영어를 대상으로 연구가 진행 되었지만, 최근에는 영어가 아닌 다른 언어에 대한 적용이 시도되고 있다. 본 논문에서는 관계 어휘의 유형을 동사형과 명사형 2가지로 정의하고, 각 유형별로 구문 분석 결과 기반의 서로 다른 방법론을 적용하는 한국어 대상 무제한 정보추출 시스템을 소개한다. 동사형 관계 어휘에 대해서는 의존 관계 기반의 추출 규칙을 적용하고, 명사형 관계 어휘에 대해서는 대량의 말뭉치로부터 자동으로 학습한 의존 관계 구조 기반의 추출 패턴을 적용한다. 임의의 100개 문장에 대해서 수행한 결과는 산출된 전체 트리플에 대해 0.8이상의 정밀도를 보임으로써 본 논문에서 제안하는 방법의 효용성을 증명하였다.

• Journal of KIISE
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• v.44 no.4
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• pp.383-391
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• 2017

As we enter a new era of Big Data, the amount of semantic data has rapidly increased. In order to derive meaningful information from this large semantic data, studies that utilize the SWRL(Semantic Web Rule Language) are being actively conducted. SWRL rules are based on data extracted from a user's empirical knowledge. However, conventional reasoning systems developed on single machines cannot process large scale data. Similarly, multi-node based reasoning systems have performance degradation problems due to network shuffling. Therefore, this paper overcomes the limitations of existing systems and proposes more efficient distributed inference methods. It also introduces data partitioning strategies to minimize network shuffling. In addition, it describes a method for optimizing the incremental reasoning process through data selection and determining the rule order. In order to evaluate the proposed methods, the experiments were conducted using WiseKB consisting of 200 million triples with 83 user defined rules and the overall reasoning task was completed in 32.7 minutes. Also, the experiment results using LUBM bench datasets showed that our approach could perform reasoning twice as fast as MapReduce based reasoning systems.

• Annual Conference on Human and Language Technology
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• 2012.10a
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• pp.53-57
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• 2012

본 논문은 소셜 미디어 기반 의사결정 지원 시스템인 '소셜위즈덤'에 포함된 이벤트 템플릿 추출에 대해서 소개한다. 의사결정 지원 시스템은 경제적, 사회적 중요사항을 결정할 수 있도록 관련 정보와 인사이트(Insight)를 제공하는 정보시스템을 이른다. 기존 시스템은 단지 특정 키워드 빈도나 공기하는 키워드들의 관계만을 제공하였다. 그러나, 소셜위즈덤은 이벤트로 정의되는 주체(Subject), 이벤트 속성(Event-Property), 객체(Object)의 트리플(Triple) 집합인 템플릿을 추출하여 이를 기반으로 이벤트 정보를 함께 제공한다. 템플릿 추출은 고정밀 언어분석의 관계추출 기술과 온톨로지에 기반한 템플릿 제약 및 필터링 규칙을 이용하였다. 수작업으로 구축한 평가데이터로 평가한 결과, 템플릿 추출 성능(F-Score)은 뉴스 0.544, 블로그 0.3386, 트위터 0.3251이고 전체 통합 성능은 0.4648이었다. 필터링 성능(Accuracy)은 뉴스 0.7257, 블로그 0.6122, 트위터 0.6207이고 전체 통합 성능은 0.722이었다.

• The KIPS Transactions:PartB
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• v.18B no.5
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• pp.295-304
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• 2011

To effectively manage research information in the field of national defense, metadata about the information should be managed systematically, and an integrated system to help convergence and management of the information should be implemented based on the metadata. In addition, the system should provide the users with effective integrated search services in a mobile environment, because searching via the use of mobile devices is increasing. The objective of this paper is to suggest a MSISS (Mobile Semantic Integrated Search System), which satisfies the requirements for effective management of the national defense research information. Specifically, we defined national defense research ontologies and national defense research rules after analyzing the Dublin Core metadata and database information of the major military research institutions. We implemented a prototype system for MSISS to demonstrate the use of the ontologies and rules for semantic integrated searching of the military research information. We also presented a triple-based search service to support semantic integrated search in a mobile environment and suggested future mobile semantic integrated search services.