• 제목/요약/키워드: system theory

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러프집합을 이용한 통합형 채권등급 평가모형 구축에 관한 연구 (A Hybrid Credit Rating System using Rough Set Theory)

  • 박기남;이훈영;박상국
    • 한국경영과학회지
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    • 제25권3호
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    • pp.125-135
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    • 2000
  • Many different statistical and artificial intelligent techniques have been applied to improve the predictability of credit rating. Hybrid models and systems have also been developed by effectively combining different modeling processes or combining the outcomes of individual models. In this paper, we introduced the rough set theory and developed a hybrid credit rating system that combines individual outcomes in terms of rough set theory. An experiment was conducted to compare the prediction capability of the system with those of other methods. The proposed system based on rough set method outperformed the others.

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Control of voltage collapse in an electrical power system using center manifold theory

  • 이병준
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1996년도 추계학술대회 논문집 학회본부
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    • pp.88-90
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    • 1996
  • In this paper center manifold theory is reviewed and its application to the control of bifurcations is explored. When applying the theory to a sample power system, we study the stabilization of bifurcation points using controls depending only on the rotor angular velocity of a generator. Under such a control it is shown that the system is not locally stabilizable when control is applied through mechanical power, and the system is locally stabilizable when the control is applied to the capacitor compensator.

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사회과학 분야 사회적 체계 이론 연구의 지식 시각화와 매핑 - Niklas Luhmann을 중심으로 - (Knowledge Visualization and Mapping of Studies on Social Systems Theory in Social Sciences: Focused on Niklas Luhmann)

  • 박성우;홍소람
    • 한국문헌정보학회지
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    • 제56권1호
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    • pp.253-275
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    • 2022
  • Niklas Luhmann은 사회학 이론가들 중 가장 논쟁적이고 난해한 학자이면서 동시에 근 10년간 후속연구가 증가하고 있는 학자이다. 이 연구의 목적은 Luhmann의 후속연구들이 Luhmann의 난해한 개념을 어떻게 사용하고 있는지를 관찰하는 것이다. 이 연구는 선행연구와 달리 분석의 단위를 논문이 아니라 키워드로 채택하였다. 키워드는 개념을 관찰 가능하게 만드는 언어적 구성물이기 때문이다. Web of Science의 검색결과 나온 139편의 사회과학 분야 논문의 키워드를 동시출현빈도 분석하였다. 연구 결과는 다음과 같다. 첫째, 가장 중요한 키워드가 Luhmann의 이름과 이론의 이름이었다. 둘째, 클러스터링은 사회적 체계 이론, 일반체계이론, 법 체계와 정치체계, Luhmann 이론의 사회이론적 의의 등 4가지로 묶였다. 셋째, 핵심어가 'systems theory(일반체계이론)', 'communication(소통)', 'Autopoiesis(자기생산)', 'risk(위험)', 'legal system(법 체계)', 'functional differentiation(기능적 분화)', 'environment(환경)', 'social theory(사회적 이론)', 'sociological theory(사회학적 이론)', 'structural coupling(구조적 연결)', 'systems(체계들)', 'evolution(진화)'로 도출되었다. 이 연구의 의의는 다음과 같다. 첫째, 핵심어를 도출해내 Luhmann의 이론을 처음 접근하는 사람들에게 유용한 접근점을 제공하였다. 둘째, 난해한 이론적 연구의 동향 분석에도 키워드 네트워크를 통한 내용분석이 가능함을 증명하였다.

시스템적 사고에 기반한 사회 시스템의 이해와 응용 : Cellular Automata를 이용한 협력모형을 중심으로 (Understanding and application of the social system based on the system thinking : Focus on the cooperation model using Cellular Automata)

  • 고길곤
    • 한국시스템다이내믹스연구
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    • 제1권1호
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    • pp.133-157
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    • 2000
  • This paper deals with the social system from the point of system thinking consisting the fundamental construct of system dynamics. The Bertalanffy's general system theory, having been criticized because of its ambiguity, and the complex science theory, emerging system theory, are integrated by using the system thinking which is characterized with three concepts, 'feedback thinking', 'dynamic thinking', 'operational thinking'. In the integration, system thinking suggests the dynamic pattern of the social system have not only an equilibrium status but also complex status. The science of complexity gives an implication to system dynamics the important of the uncertainty and complexity if we interpret the social system as an open system. To show more concrete description, I simulate the cooperation model based on the iterated prisoner dilemma. The simulation results show the diverse patterns of cooperation and betrayal. Especially the sensitivity of initial payoff will cause the chaotic strategic landscapes as the game gose on. These results mean that we should not give the hasty prescription to control social system artificially. Because social system retains the self-organizing force in itself.

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유아사 야스오(탕천태웅(湯淺泰雄))의 경락학설(經絡學說)에 대(對)한 소고(小考) (A Study on Yuasa Yasuo's Meridian Theory)

  • 송석모;이상룡
    • Korean Journal of Acupuncture
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    • 제27권4호
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    • pp.25-34
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    • 2010
  • Objective : This paper introduces a unique meridian theory developed by Japanese philosopher Yuasa Yasuo. Method : His meridian theory is well organized in his philosophy, so we systematically review his major works and philosophy from which we systematize his meridian theory. And we critically examine it with current studies. Results and Conclusions : He tried to overcome Cartesian mind-body dualism by Eastern thought and newly developing neurophysiology. He articulated "body scheme" from human information systems, primarily nervous system and meridian system, which regulate physiological functions. It consists of 1st external sensory motor circuit, 2nd circuit of coenesthesis, 3rd emotion-instinct circuit and 4th circuit of unconscious quasi-body. Meridian system is the 4th circuit, through which he thought various affect(emotion) flows. Based on the relationship of emotion-autonomic nervous system- meridian-skin, he tried to confirm the existence of meridian system. His theory illuminates mind-body problem and emotion-meridian relationship in traditional East Asian medicine.

The use of network theory to model disparate ship design information

  • Rigterink, Douglas;Piks, Rebecca;Singer, David J.
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제6권2호
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    • pp.484-495
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    • 2014
  • This paper introduces the use of network theory to model and analyze disparate ship design information. This work will focus on a ship's distributed systems and their intra- and intersystem structures and interactions. The three system to be analyzed are: a passageway system, an electrical system, and a fire fighting system. These systems will be analyzed individually using common network metrics to glean information regarding their structures and attributes. The systems will also be subjected to community detection algorithms both separately and as a multiplex network to compare their similarities, differences, and interactions. Network theory will be shown to be useful in the early design stage due to its simplicity and ability to model any shipboard system.

일차 Dynamic을 갖는 계통에 대한 가변구조 제어기의 설계 (The Design of Variable Structure Controller for the Systems Having the First Order Dynamic)

  • 박귀태;최종경;김동식
    • 대한전기학회논문지
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    • 제41권4호
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    • pp.392-399
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    • 1992
  • This paper will describe the application of variable structure control theory to the first order dynamic system and verify its robustness. The study on the first order dynamic system control which has been essential part for the control of servo motor (AC,DC) systems has been excluded in the study of variable structure control system(VSCS) because this first order system was not applicable to the previous variable structure control theory. So, for the robustness control of first order dynamic system with variable structure control theory, we propose modified switching function synthesis which guarantees the advantages of conventional VSCS and removes reaching phase which is regarded as shortcomings in VSCS. And we demonstrate the practical potential of implementation about this theory by simulation results of AC motor variable speed control.

일차 dynamic을 갖는 계통에 대한 가변구조 제어기의 설계 (The design of variable structure controller for the systems having the first order dynamic)

  • 박귀태;최중경;강윤관
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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    • pp.179-184
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    • 1991
  • This paper will describe the application for variable structure control theory to the first order dynamic system and verify it's robustness. The study on the first order dynamic system control which has been essential part for the control of servo motor (AC, DC) systems has been excluded in the study of variable structure control system(VSCS) because this first order system was not applicable to the previous variable structure control theory. So, for the robustness control of first order dynamic system with variable structure control theory, we propose modified switching function synthesis which guarantees the advantages of conventional VSCS and removes reaching phase which regards as shortcomings in VSCS. And we demonstrate the practical potential of implementation about this theory by simulation results of AC motor variable speed control.

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능동전력필터를 위한 확장된 전류 동기 검출 알고리즘 (Algorithm of Extended Current Synchronous Detection for Active Power Filters)

  • 정영국
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2000년도 전력전자학술대회 논문집
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    • pp.111-114
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    • 2000
  • Harmonics and fundamental reactive power of nonlinear loads in serious unbalanced power condition are compensated by current synchronous detection(CSD) theory which is also acceptable for single phase power system, but the CSD theory is not suitable any more in case of controlled independently harmonics and reactive component. Therefore a new algorithm the extended current synchronous detection (ECSD)theory for a three phase active power filter based on decomposition of fundamental reactive distorted components is proposed in this paper. The proposed ECSD theory is simulated and tested comparison with a few power theories under asymmtrical condition in power system.

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자연어 질의가 가능한 퍼지 기반 지능형 전자상거래 검색 에이전트 (Fuzzy Theory based Electronic Commerce Navigation Agent that can Query by Natural Language)

  • 김명순;정환묵
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2001년도 춘계학술대회 학술발표 논문집
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    • pp.270-273
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    • 2001
  • In this paper, we proposed the intelligent navigation agent model for successive electronic commerce management. For allowing intelligence, we used fuzzy theory. Fuzzy theory is very useful method where keywords have vague conditions and system must process that conditions. So, using theory, we proposed the model that can process the vague keywords effectively. Through the this, we verified that we can get the more appropriate navigation result than any other crisp retrieval keywords condition.

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