• 제목/요약/키워드: Approach theory

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A Co-Evolutionary Computing for Statistical Learning Theory

  • Jun Sung-Hae
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제5권4호
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    • pp.281-285
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    • 2005
  • Learning and evolving are two basics for data mining. As compared with classical learning theory based on objective function with minimizing training errors, the recently evolutionary computing has had an efficient approach for constructing optimal model without the minimizing training errors. The global search of evolutionary computing in solution space can settle the local optima problems of learning models. In this research, combining co-evolving algorithm into statistical learning theory, we propose an co-evolutionary computing for statistical learning theory for overcoming local optima problems of statistical learning theory. We apply proposed model to classification and prediction problems of the learning. In the experimental results, we verify the improved performance of our model using the data sets from UCI machine learning repository and KDD Cup 2000.

Theory and Prediction of Turbulent Transition

  • Dou, Hua-Shu;Khoo, Boo-Cheong
    • International Journal of Fluid Machinery and Systems
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    • 제4권1호
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    • pp.114-132
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    • 2011
  • We have proposed a new approach based on energy gradient concept for the study of flow instability and turbulent transition in parallel flows in our previous works. It was shown that the disturbance amplitude required for turbulent transition is inversely proportional to Re, which is in agreement with the experiments for imposed transverse disturbance. In present study, the energy gradient theory is extended to the generalized curved flows which have much application in turbomachinery and other fluid delivery devices. Within the frame of the new theory, basic theorems for flow instability in general cases are provided in details. Examples of applications of the theory are given from our previous studies which show comparison of the theory with available experimental data. It is shown that excellent agreement has been achieved for several configurations. Finally, various prediction methods for turbulent transition are reviewed and commented.

Performance Analysis of VaR and ES Based on Extreme Value Theory

  • Yeo, Sung-Chil
    • Communications for Statistical Applications and Methods
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    • 제13권2호
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    • pp.389-407
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    • 2006
  • Extreme value theory has been used widely in many areas of science and engineering to deal with the assessment of extreme events which are rare but have catastrophic consequences. The potential of extreme value theory has only been recognized recently in finance area. In this paper, we provide an overview of extreme value theory for estimating and assessing value at risk and expected shortfall which are the methods for modelling and measuring the extreme financial risks. We illustrate that the approach based on extreme value theory is very useful for estimating tail related risk measures through backtesting of an empirical data.

사서의 직업사회화 경험의 통합 요인 - 질적 다방법 연구 - (Integrated Factors Related to Occupational Socialization of Librarians: A Qualitative Multimethod Study)

  • 김갑선
    • 한국도서관정보학회지
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    • 제41권4호
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    • pp.99-126
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    • 2010
  • 본 연구는 질적 다방법을 적용하여 복합 현상인 직업 사회화 경험의 실체이론을 구성하는 요인들을 통합 도출한 것이다. 순차적으로 이루어진 일련의 3개 질적 선행연구의 총 참여자는 이론적 표집에 의한 42명의 현직 사서 및 사서교사들이다. 질적 다방법 접근의 최종 통합방법으로서 근거이론 접근을 적용하여 3개의 선행연구 결과 및 심층면담자료의 최종분석과 비교, 재검토, 통합이 이루어졌다. 그 결과 도출된 통합 구성요인은 다음과 같다: 전공 공감, 주변부 인식 극복하기, 사회적 몰이해, 열악함, 업무 공감, 사회 변화, 이용자에 대한 인식, 도서관 조직문화, 조직인간관계, 지속교육과 교류, 전문성 추구, 업무 전략, 대인관계 전략, 슬럼프와 위기 대응 전략, 개인 성장 및 발전도모전략, 조직 대응 및 몰인식 대응 전략, 사서직과 자아일치, 자아 불일치.

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정보체계 탐구.평가의 철학적 분석 모델과 그 방법론적 활용: 비판 실재론적 접근 (A Study on the Philosophical Analysis Model and its Methodological Application of Information Systems Research.Evaluation - A Critical Realist Approach -)

  • 고창택
    • 한국정보시스템학회지:정보시스템연구
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    • 제16권4호
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    • pp.131-155
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    • 2007
  • The purpose of this thesis is to study on the philosophical analysis model and its methodological application of information systems research evaluation from critical realist perspective. Fist of all, I examine ontological epistemological methodological assertions of critical realism. Because the philosophy of critical realism is an opportunity for information systems study. I examine Dobson and Mutch's critical realist perspective on actors-structure model. I suggest a critical realist actors-praxis-structure model. This model provides the potential for a new approach to social investigations in its provision of an ontology for the analytical separation of structure and agency. Of most importance might be the incorporation of non-humans into the analysis of social interaction and of technology into the elaboration of structures. I also examine Tsoukas's critical realistic meta-theory of management. I suggest a critical realist IS management model. This model elucidate the nature of management and delineate the scope of applicability of various perspectives on management. The causal powers of management reside in the real domain and, taken together, their logics are contradictory, the effects of their contradictory composition are contingent upon prevailing contingencies. I analyze Carlsson's theory of design knowledge. His framework builds on that the aim of IS design science research is to develop practical knowledge for the design and realization of different classes of IS initiatives, where IS are viewed as socio-technical systems and not just IT artefacts. The framework proposes that the output of IS design science research is practical IS design knowledge in the form of field-tested and grounded technological rules. The IS design knowledge is developed through an IS design science research cycle. In conclusion, I think that IS actors-praxis-structure model, meta-theoretical IS management model, and IS design knowledge model according to critical realistic approach are very useful for IS research evaluation. Nevertheless, important problems are left not resolved.

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비평면 양력면 이론과 반복적 캠버변형 기법을 이용한 날개의 실속 특성 예측 (Stall Prediction of Wing Using the Nonplanar Lifting Surface Theory and an Iterative Decambering Approach)

  • 조정현;조진수;조연우
    • 한국항공우주학회지
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    • 제34권10호
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    • pp.1-6
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    • 2006
  • 본 연구에서는 3차원 날개의 실속 특성을 예측하였다. 날개의 실속 특성을 해석하기 위해 반복적 캠버변형 기법을 비평면 양력면 이론에 도입하였다. 반복적 캠버변형 기법은 기지의 2차원 에어포일 데이터를 이용하여 3차원 날개의 실속 특성을 해석한다. 날개의 한 단면에서의 캠버변형이 날개의 다른 단면에 미치는 영향은 다차원 뉴턴 반복법을 사용하여 고려하였다. 해석 결과는 실험값과 타 전산해석 결과와 비교하여 일치되는 결과를 보였다. 본 기법은 비틀림 또는 조종면을 갖는 어떠한 날개에도 적용이 가능하며 또한 날개와 날개의 상호 작용이 있을 때의 실속 특성도 예측 가능하다.

Development of a Simulator by Assimilating Survey Approach with Computational Theory for the Research of Organizational Activities

  • Nakamura, Yoshiki
    • Industrial Engineering and Management Systems
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    • 제9권4호
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    • pp.312-322
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    • 2010
  • An enterprise must achieve both a sound organizational management and effective development of individual members while maintaining a balanced approach. Relative to this, there is a research field dubbed as Organizational Activation. However, there is a necessity to clarify various factors required for organizational activation and to propose a methodology for organization management. This study is an attempt to create a model from an organization-a University Seminar Class-and agents therein-the Students and the Teacher-with an assumed goal of advancing together toward the students' self-growth. The model is expressed on two dimensional planes with vectors through a computer. Vectors are composed of the growth, demand, member, hindrance and student vectors. These vectors provide data to the mathematical model for a simulation. Each agent provided the individual information from the questionnaire-conducted to 169 university students. From the analysis data and extrapolations, this study was able to craft a guideline for future seminar activity. It also examines the possibility of assimilation of the Questionnaire Approach and that of the Computational Organization Theory approach. Finally, this study discusses the future possibility of application of the Assimilated Method for research and development, and for project management.

A New Approach to Case Theory

  • Alam, Yukiko Sasaki
    • 한국언어정보학회:학술대회논문집
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    • 한국언어정보학회 1994년도 The Proceedings of the 1994 Kyoto Conference
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    • pp.49-62
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    • 1994
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