• Title/Summary/Keyword: Knowledge graph

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Verification of Subsumption Anomalies in Hybrid Knowledge Bases : A Meta-graph Approach (혼합 지식 기반 내 포함 이상의 검증 메타 그라프적 접근)

  • Lee, Sun-Ro
    • Asia pacific journal of information systems
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    • v.7 no.2
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    • pp.163-183
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    • 1997
  • As object models and hybrid knowledge are increasingly used in current information systems development, Is-a structures need to be more formally defined, and subsequently subsumption related anomalies need to be detected with minimal declaration of meta knowledge. This paper extends a metagraph in the hybrid environments and demonstrates its utilities for detecting such anomalies that can occur from semantics and dynamics unique to the hybrid knowledge and data structure.

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A Study on Teachers' Knowledge of Mathematics -With Respect to the Concept of Function- (교사의 수학적 지식에 대한 연구 -함수 개념과 관련하여-)

  • 김원경;김용대
    • The Mathematical Education
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    • v.41 no.1
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    • pp.101-108
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    • 2002
  • The purpose of this study is to estimate teachers' knowledge of mathematics via the concept of function. For the purpose, a survey was done to measure their knowledge of mathematics. The result obtained from the survey was as follows With respect to the knowledge on concept of friction, they understood the function as ordered pairs and graph rather than as relation and expression. This study reached the following conclusions from the result : They have the more static cognition than the dynamic one on the concept of unction.

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Automatic Construction of SHACL Schemas for RDF Knowledge Graphs Generated by R2RML Mappings

  • Choi, Ji-Woong
    • Journal of the Korea Society of Computer and Information
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    • v.25 no.8
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    • pp.9-21
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    • 2020
  • With the proliferation of RDF knowledge graphs(KGs), there arose a need of a standardized schema representation of the graph model for effective data interchangeability and interoperability. The need resulted in the development of SHACL specification to describe and validate RDF graph's structure by W3C. Relational databases(RDBs) are one of major sources for acquiring structured knowledge. The standard for automatic generation of RDF KGs from RDBs is R2RML, which is also developed by W3C. Since R2RML is designed to generate only RDF data graphs from RDBs, additional manual tasks are required to create the schemas for the graphs. In this paper we propose an approach to automatically generate SHACL schemas for RDF KGs populated by R2RML mappings. The key of our approach is that the SHACL shemas are built only from R2RML documents. We describe an implementation of our appraoch. Then, we show the validity of our approach with R2RML test cases designed by W3C.

An Extended AND-OR Graph-Based Expert System in Electronic Commerce

  • 이건창;조형래;권순재
    • Proceedings of the Korea Inteligent Information System Society Conference
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    • 1999.10a
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    • pp.281-289
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    • 1999
  • The objective of this paper is to propose a brand new interface mechanism to provide more intelligent decision making support for EC problems. Its main virtue is based on a numerical process mechanism by using an Extended AND-OR Graph (EAOG)-based logic algebra. Using this mechanism, decision makers engaged in electronic commerce (EC) can effectively deal with complicated decision making problems. In the field of traditional expert systems research, AND-OR Graph approach has been suggested as a useful tool for representing the logic flowchart of the forward and/or backward chaining inference methods. However, the AND-OR Graph approach cannot be effectively used in the EC problems in which real-time problem-solving property should be highly required. In this sense, we propose the EAOG inference mechanism for EC problem-solving in which heurisric knowledge necessary for intelligent EC problem-solving can be represented in a form of matrix. Finally, we have proved the validity of our approach with several propositions and an illustrative EC example

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Power Plant Fault Monitoring and Diagnosis based on Disturbance Interrelation Analysis Graph (교란들의 인과관계구현 데이터구조에 기초한 발전소의 고장감시 및 고장진단에 관한 연구)

  • Lee, Seung-Cheol;Lee, Sun-Gyo
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.51 no.9
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    • pp.413-422
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    • 2002
  • In a power plant, disturbance detection and diagnosis are massive and complex problems. Once a disturbance occurs, it can be either persistent, self cleared, cleared by the automatic controllers or propagated into another disturbance until it subsides in a new equilibrium or a stable state. In addition to the Physical complexity of the power plant structure itself, these dynamic behaviors of the disturbances further complicate the fault monitoring and diagnosis tasks. A data structure called a disturbance interrelation analysis graph(DIAG) is proposed in this paper, trying to capture, organize and better utilize the vast and interrelated knowledge required for power plant disturbance detection and diagnosis. The DIAG is a multi-layer directed AND/OR graph composed of 4 layers. Each layer includes vertices that represent components, disturbances, conditions and sensors respectively With the implementation of the DIAG, disturbances and their relationships can be conveniently represented and traced with modularized operations. All the cascaded disturbances following an initial triggering disturbance can be diagnosed in the context of that initial disturbance instead of diagnosing each of them as an individual disturbance. DIAG is applied to a typical cooling water system of a thermal power plant and its effectiveness is also demonstrated.

An Extended AND-OR Graph-based Simulation and Electronic Commerce

  • Lee, Kun-Chang;Cho, Hyung-Rae
    • Proceedings of the Korea Society for Simulation Conference
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    • 1999.04a
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    • pp.242-250
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    • 1999
  • The objective of this paper is to propose an Extended AND-OR Graph (EAOG)-driven inferential simulation mechanism with which decision makers engaged in electronic commerce (EC) can effectively deal with complicated decision making problem. In the field of traditional expect systems research, AND-OR Graph approach cannot be effectively used in the EC problems in which real-time problem-solving property should be highly required. In this sense, we propose the EAOG inference mechanism for EC problem-solving in which heurisric knowledge necessary for intelligent EC problem-solving can be represented in a form of matrix. The EAOG method possesses the following three characteristics. 1. Realtime inference: The EAOG inference mechanism is suitable for the real-time inference because its computational mechanism is based on matrix computation.2. Matrix operation: All the subjective knowledge is delineated in a matrix form, so that inference process can proceed based on the matrix operation which is computationally efficient.3. Bi-directional inference: Traditional inference method of expert systems is based on either forward chaining or based on either and computational efficiency. However, the proposed EAOG inference mechanism is generically bi-directional without loss of both speed and efficiency.We have proved the validity of our approach with several propositions and an illustrative EC example.

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A Study Nuenal Model of Concept Retrieval (개념 검색의 신경회로망 모델에 관한 연구)

  • Kauh, Yong-Hoon;Park, Sang-Hui
    • Proceedings of the KIEE Conference
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    • 1990.11a
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    • pp.450-456
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    • 1990
  • In this paper, production system is implemented with the inferential neural network model using semantic network and directed graph. Production system can be implemented with the transform of knowledge representation in production system into semantic network and of semantic network into directed graph, because directed graphs can be expressed by neural matrices. A concept node should be defined by the state vector to calculated the concepts expressed by matrices. The expressional ability of neunal network depends on how the state vector is defined. In this study, state vector is overlapped and each overlapping part acts as a inheritant of concept.

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A Natural Language Query Framework for the Semantic Web

  • Kim, Jin-Sung
    • Journal of the Korean Institute of Intelligent Systems
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    • v.18 no.1
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    • pp.127-132
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    • 2008
  • This study proposes a Natural Language Query Framework (NLQF) for the semantic web. It supports an intelligent inference at a semantic level. Most of previous researches focused on the knowledge representation on the semantic web. However, to revitalize the intelligent e-business on the semantic web, there is a need for semantic level inference to the web information. To satisfy the need, we will review the knowledge/resource representation on the semantic web such as RDF, Ontology and Conceptual Graph (CG), and then discuss about the natural language (NL) inference. The result of this research could support a natural interface for the semantic web. Furthermore, we expect that the NLQF can be used in the semantic web-based business communications.

An Approach to Constructing Knowledge Graph for Recommender Systems based on Object Relations (객체 간 관계 정보를 포함하는 지식 그래프 구축 기법 및 추천 시스템에서의 활용 방안)

  • Park, Sung-Jun;Bae, Hong-Kyun;Chae, Dong-Kyu;Kim, Sang-Wook
    • Proceedings of the Korea Information Processing Society Conference
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    • 2020.11a
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    • pp.759-760
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    • 2020
  • 최근 사용자, 상품, 그리고 상품의 메타 정보 사이의 관계를 표현한 지식 그래프 (knowledge graph) 가 추천 시스템 분야에서 많은 관심을 받고 있으며 활발히 이용되고 있다. 하지만 기존의 지식 그래프는 각 노드 (사용자, 상품, 메타 정보 등) 사이의 단순한 사실 관계만을 표현하고 있으며, 이는 사용자의 선호도를 정확히 파악하는 데 한계가 있다. 본 논문에서는 지식 그래프의 정보 부족 문제를 보완하기 위해 각 상품에 남겨진 텍스트 리뷰를 감정 분석 (sentiment analysis) 하고, 이를 각 노드 간의 선호도 정보로 활용하여 지식 그래프를 구축하는 방법을 제안한다.

Knowledge Graph Embedding Methods for Political Stance Prediction: Performance Evaluation (뉴스 기사의 정치적 성향 판단을 위한 지식 그래프 임베딩 기법의 효과 분석)

  • Seongeun Ryu;Yunyong Ko;Sang-Wook Kim
    • Proceedings of the Korea Information Processing Society Conference
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    • 2023.05a
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    • pp.519-521
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    • 2023
  • 온라인 뉴스 플랫폼의 발전은 에코 챔버(echo chamber) 효과와 정치적 양극화를 심화시키며, 이를 완화하기 위한 선행 연구로 뉴스 기사의 정치적 성향을 판단하는 연구가 필요하다. 기존 연구는 외부 지식 그래프를 활용하여 뉴스 기사의 텍스트 정보를 더욱 풍부하게 표현한다. 그러나, 외부 지식을 임베딩하는 지식 그래프 임베딩(knowledge graph embedding, KGE) 방법은 다양하며, 각 KGE 방법이 정치적 성향 예측 정확도에 미치는 효과에 대해서 충분히 연구되지 않았다. 본 논문에서는 정치적 성향 예측에 외부 지식의 활용을 최대화하기 위한 다양한 KGE 방법들의 효과를 분석한다. 실험 결과, 외부 지식 그래프 내의 개체들 간 복잡한 관계를 간단하고 정확하게 표현 가능한 ModE 방법을 활용하는 것이 정치적 성향 예측에 가장 효과적이라는 것을 확인하였다.