• 제목/요약/키워드: domain specific knowledge

검색결과 188건 처리시간 0.02초

지식 추상화 계층의 구축과 관리 (Management of Knowledge Abstraction Hierarchy)

  • 허순영;문개현
    • 한국경영과학회지
    • /
    • 제23권2호
    • /
    • pp.131-156
    • /
    • 1998
  • Cooperative query answering is a research effort to develop a fault-tolerant and intelligent database system using the semantic knowledge base constructed from the underlying database. Such knowledge base has two aspects of usage. One is supporting the cooperative query answering Process for providing both an exact answer and neighborhood information relevant to a query. The other is supporting ongoing maintenance of the knowledge base for accommodating the changes in the knowledge content and database usage purpose. Existing studies have mostly focused on the cooperative query answering process but paid little attention on the dynamic knowledge base maintenance. This paper proposes a multi-level knowledge representation framework called Knowledge Abstraction Hierarchy (KAH) that can not only support cooperative query answering but also permit dynamic knowledge maintenance. The KAH consists of two types of knowledge abstraction hierarchies. The value abstraction hierarchy is constructed by abstract values that are hierarchically derived from specific data values in the underlying database on the basis of generalization and specialization relationships. The domain abstraction hierarchy is built on the various domains of the data values and incorporates the classification relationship between super-domains and sub-domains. On the basis of the KAH, a knowledge abstraction database is constructed on the relational data model and accommodates diverse knowledge maintenance needs and flexibly facilitates cooperative query answering. In terms of the knowledge maintenance, database operations are discussed for the cases where either the internal contents for a given KAH change or the structures of the KAH itself change. In terms of cooperative query answering, database operations are discussed for both the generalization and specialization Processes, and the conceptual query handling. A prototype system has been implemented at KAIST that demonstrates the usefulness of KAH in ordinary database application systems.

  • PDF

분류기 성능 향상을 위한 범주 속성 가상예제의 생성과 선별 (Generation and Selection of Nominal Virtual Examples for Improving the Classifier Performance)

  • 이유정;강병호;강재호;류광렬
    • 한국정보과학회논문지:소프트웨어및응용
    • /
    • 제33권12호
    • /
    • pp.1052-1061
    • /
    • 2006
  • 본 논문에서는 베이지안 네트워크를 기반으로 생성하고 평가한 가상예제를 활용하여 범주 속성 데이타에 대한 분류 성능을 향상시키는 방안을 제안한다. 가상예제를 활용하는 종래의 연구들은 주로 수치 속성 데이타를 대상으로 하였고, 대상 도메인에 특화된 지식을 활용하여 특정 학습 알고리즘의 성능을 향상시키는 것을 목표로 하였다. 본 연구에서는 도메인에 특화된 지식을 활용하는 대신 주어진 훈련 집합을 기반으로 만든 베이지안 네트워크로부터 범주 속성 가상예제를 생성하고, 그 예제가 네트워크의 조건부 우도를 증가시키는데 기여할 경우 유용한 것으로 선별한다. 이러한 생성 및 선별과정을 반복하여 적절한 크기의 가상예제 집합을 수집하여 사용한다. 범주 속성 데이타를 대상으로 한 실험 결과, 여러 가지 학습 모델의 성능이 향상됨을 확인하였다.

온톨로지 기반 영상이해 시스템 (Ontology-based Image Understanding Systems)

  • 이인근;서석태;정혜천;손세호;권순학
    • 한국지능시스템학회논문지
    • /
    • 제17권3호
    • /
    • pp.328-335
    • /
    • 2007
  • 온톨로지는 공유된 개념과 그 개념들 사이의 관계로 표현된다. 이러한 온톨로지를 사용하여 인간과 시스템에 대한 지식의 공유에 관한 연구가 활발히 이루어져 왔다. 예를 들면, 온톨로지의 설계 및 구축에 의한 영상이해를 들 수 있다. 그러나 온톨로지에 기반한 영상이해 방식 중 대부분의 기존 방식은 개념적인 연구에 그칠 뿐 구체적인 방법을 제시하지는 못하였다. 본 논문에서는 온톨로지로 표현된 지식에 근거하여 영상을 이해하는 다음과 같은 영상이해 프로세스 및 시스템을 제안한다. i)특정 분야의 지식을 온톨로지로 표현하고, ii)영상 처리 및 분석 과정을 통해 영상을 구성하는 객체들의 특징을 추출하며, iii)객체의 특징으로부터 객체의 개념을 해석하고, iv)온톨로지 추론을 통해 영상 해석 과정에서의 애매성을 줄인다. 제안된 영상 이해 프로세스에 기반하여 영상이해 시스템을 구축하고, 특정 분야에서의 실험을 통하여 제안된 프로세스와 시스템의 효용성을 확인한다.

별과 우주 단원에 대한 중학교 과학 교사의 주제-특이적 PCK 사례연구 (A Case Study of Middle School Science Teachers' Topic-Specific Pedagogical Content Knowledge on the Unit of Stars and Universe)

  • 이기영;맹승호;박영신;이정아;오현석
    • 한국과학교육학회지
    • /
    • 제34권4호
    • /
    • pp.393-406
    • /
    • 2014
  • PCK는 본질적으로 영역-특이적이며 주제-특이적인 교사 전문성 지식이라는 전제 하에, 이 연구에서는 현직 중학교 과학 교사들을 대상으로 교사 지식 및 실행 측면에서 천문 내용에 대한 주제-특이적 PCK를 분석하였다. 이를 위해 4명의 중학교 과학 교사를 대상으로 8학년 '별과 우주' 단원의 3개 주제(별자리와 별의 위치, 연주시차와 별의 거리, 우주의 팽창)에 대한 수업을 관찰하고 녹화하였으며, 녹화 후 참여교사의 교수학적 생각을 심층적으로 분석하기 위해 비디오 자극 회상면담을 실시하였다. 수업 녹화 및 교사 면담 자료는 모두 전사하여 분석에 활용하였다. 양적 및 질적으로 통합된 수업 분석을 위한 PCK분석 프로토콜을 개발하였으며, 이를 적용하여 PCK 수준과 구성요소별 특징을 분석하였다. 연구 결과, 참여교사들은 주제에 따라 구성요소에 따라 다양한 PCK 수준을 나타내었으며, 과학 교수 지향이 참여교사 PCK의 특징을 형성하는데 중추적인 역할을 한다는 것을 알 수 있었다. 또한, 천문 영역에 특이적인 실행인 천문학적 사고(공간적 및 시스템 사고)가 가르치는 핵심 개념에 적절하게 조합되지 못하는 것으로 분석되었다. 이러한 연구 결과를 토대로 과학 교사 전문성 계발을 위한 PCK 발달과정 연구의 함의를 논의하였다.

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
    • /
    • 제20권2호
    • /
    • pp.125-155
    • /
    • 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.

창의적 문제 해결력 신장을 위한 중학교 과학 교육과정 연구-현행 교육과정과 수업현장 분석을 중심으로- (A Study for the Middle School Science Curriculum to Enhance Creative Problem Solving Abilities-Focusing on the 6th National Curriculum and Classroom Observations-)

  • 최경희;조연순;조덕주
    • 한국과학교육학회지
    • /
    • 제18권2호
    • /
    • pp.149-160
    • /
    • 1998
  • 본 연구는 창의적 문제해결력 신장을 위한 중등 과학 프로그램 개발의 기초연구를 위해 수행된 것이다. 기초 연구로서 제 6차 과학과 교육과정에는 창의적 문제해결력에 관한 내용이 어떻게 반영되고 있으며, 교실현장에서는 창의적 문제해결력 신장을 위한 수업이 이루어지고 있는지에 대하여 알아보았다. 이를 위하여 제 6차 중 학교 과학과 교육과정의 성격, 목표, 방법에 나타난 창의적 문제해결력의 요소를 조사하였으며, 과학 수업 관찰, 교사면담을 실시하였다. 중학교 과학과 교육과정은 특정, 총괄목표, 하위목표 모두 창의성 및 문제해결력이라는 용어를 명시함으로써 창의적 문제해결력을 강조하였다. 그러나 현 중학교 과학교육에 있어 창의적 문제해결력은 교육과정의 성격 및 총괄 목표에만 포괄적으로 기술되어 있을 뿐, 실제적으로는 실시되지 못하고 있음이 드러놨다. 또한 과학 교사들은 창의적 문제해결력에 대하여 대체로 이해하고 있었으나 교과진도 문제, 학급당 과다한 학생수, 지식중심의 교과 내용, 입시와 연관된 평가, 교사의 준비 부족으로 인하여 창의적 문제해결력 배양을 위한 수업은 거의 하지 못하고 있음을 밝혔다.

  • PDF

The Citizen Advisory Model for E-Government Service

  • Varavithya, Wanchai;Esichaikul, Vatcharaporn
    • 한국디지털정책학회:학술대회논문집
    • /
    • 한국디지털정책학회 2004년도 International Conference on Digital Policy & Management
    • /
    • pp.233-246
    • /
    • 2004
  • This paper proposes a design of a citizen advisory model under the consideration of the unique characteristics of the government, namely complex structure of goals, predominance by laws, knowledge driven organization, and the good governance objectives. The legal knowledge-based technology is explored with the aims to facilitate citizens in accessing e-government services in five phases: search, intake, decision-making, explanations, and objection and appeal phases. The design of the citizen advisory model consists of four components: specific service advice, customized form fill-in service, decision-making services, and a statement of reasons service. The prototype of the citizen advisory model is illustrated using the Thai Anti Dumping and Countervailing Act 1999 as a legal domain and e-government services example.

  • PDF

4, 5세 아동의 기수성 발달과 인지 발달의 관계 : 분석과 처리통제 이론을 중심으로 (Relationship between Understanding of Cardinality and Development of Cognitive Processing in 4- to 5-Year-Olds)

  • 이귀옥;이혜련
    • 아동학회지
    • /
    • 제26권2호
    • /
    • pp.43-53
    • /
    • 2005
  • The purpose of this study was to investigate children's acquisition of cardinality in terms of a framework that isolates two cognitive components, analysis of knowledge and control of processing. The subjects were 30 4-and 5- year-olds who were asked to solve three problems that required an understanding of cardinality. The problems were designed to place different demands on these processing components on the tasks than the 4-year-olds and correlastion among scores on the three tasks show that there is no correlation between the tower task assessing control and the two tasks that assessed analysis. The implications of the results are that aspects of symbolic development may be a broadly based process that extends beyond domain-specific boundaries.

  • PDF

퍼지추론을 이용한 연삭가공조건 설정용 전문가 시스템의 개발

  • 신상룡;김남경;송지복
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 1992년도 추계학술대회 논문집
    • /
    • pp.121-125
    • /
    • 1992
  • Grinding is considered as a very effective machining technology to attain the good surface quality of a components. However, the grinding operation still needs the skill and experience of an operator because of a lack of scientific and engineering principles. Therefore, recent development focus on expert systems which deal with domain specific knowledge in order to solve this problem. This paper describes an expert system for selecting the optimism grinding wheel by using the fuzzy reasoning and operation conditions in grinding. By the system unskilled workers will be able to make use of the knowledge and experience of skilled workers. The system is consist of programs that, (1) selection of the best wheel form among avairable wheel by using fuzzy reasoning, (2) determine wheel depth of cut, feed and wheel speed for grinding, work speed, and dressing condition. The developed system perform in using the CLIPS as a software tool and run under the IBM PC/AT as a hardware tool.

볼트의 자동공정계획수립을 위한 CBR시스템의 개발 (Developing CBR System for Bolt's CAPP)

  • 김진백
    • Asia pacific journal of information systems
    • /
    • 제9권2호
    • /
    • pp.19-37
    • /
    • 1999
  • Computer aided process planning(CAPP) is a key for implementing CIM. It is bridge between CAD and CAM and translates the design information into manufacturing instructions. Generally, manufacturing is an area where intelligent systems will not be able to rely on methods requiring formalized knowledge. Manufacturing lacks a body of knowledge that is specific, formalized, and rigorous, and which can be coded as rules or procedures. Thus expertise in manufacturing is developed over a period of many years. Case-based reasoning(CBR) offers a new approach for developing intelligent system. In the case-based approach the problem solving experience of the experts is encoded in the form of cases. CBR's retrieval process can be divided to two step. The first step is matching step, and the second step is selection step. For selecting base case, new preference heuristics were introduced using similarity concept. Similarity concept has three has three dimensions, i.e. entity similarity, structural similarity, and goal similarity. In this paper, bolt's process planning was selected an application domain. Following the test result, the new preference heuristics were approved as a useful procedure in CAPP.

  • PDF