• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.12
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• pp.2287-2297
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• 1992

The Formulation of a new Hermite straight beam element to eliminate the shear locking is presented. All the kinematic variables in Timoshenko beam are reinterpreted by the consideration of equilibrium equations together. It shows that when the modified transverse displacement field is used the Timoshenko beam looks apparently the same as the Euler beam. The element is formulated for the modified transverse displacement field to have the same interpolation scheme as that in the Hermite element. Transformation Matrix which relates a modified nodal vector with nonmodified one is also introduced to deal with general boundary conditions. Several examples are demonstrated and discussed for the purpose of verification of the concepts employed. The solutions obtained reveal that the element describes of the beam quite correctly, showing no locking and that it is also applicable to the analysis of both thin and thick beams.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.1918-1923
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• 2009

결정질 암반에서 지하수의 수리적 특성을 파악하기 위해 수행되고 있는 수리시험 방법은 정률법, 정압법, 순간주입(회복)법 등 세 가지로 구분할 수 있다. 본 연구에서 다루는 정압주입시험 (Constant Head Injection Test, CHIT)은 위의 정압법의 한 종류로 토목공학, 지질공학 분야에서 대상 구간의 투수계수 추정을 위해 널리 쓰이는 수리 시험이며, 이는 단일 패커나 이중패커를 이용하여 시험 구간을 격리하고, 격리된 구간에 일정한 압력으로 물을 주입하여 주입되는 물의 양을 파악함으로써, 시험 구간의 수리전도도(Hydraulic conductivity)를 산출하는 전통적인 수리시험이다. 본 연구에서는 수치실험을 통해 시험 구간 및 주입 압력의 크기 등 인위적인 요인에 의해 도출되는 투수계수가 어떻게 달라지는지에 대해 평가해 보았다. 일반적으로 단열 암반에서 수행한 정압주입시험의 해석에 있어 매질을 균질, 등방성 다공질이라는 가정으로 구간별 투수량계수를 산출하기 때문에, 다공성 매질의 지하수 유동을 모사하는 MODFLOW를 수치모사 코드로서 이용하였다. 시험구간의 크기 및 주입압력에 대한 민감도 분석 결과, 시험구간의 크기에 상관없이 수치모의에서 입력한 수리전도도 값에 비해 낮은 수리전도도 값이 산출되었으며, 주입 압력이 클수록 산출되는 수리전도도 값이 매질의 수리전도도 값과 차이가 났다. 민감도 분석 결과 현장수리시험에서 정압 주입시험에 의한 구간별 수리전도도 산출함에 있어 시험구간의 크기와 주입 압력 값에 대하여 고려해야 한다고 판단된다.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.317-320
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• 2004

정압주입시험(Constant Head Injection Test, CHIT)은 결정질 암반의 구간별 수리전도도 및 투수계수를 구하는 전통적인 수리시험방법이다. 본 연구에서는 Visual Modflow 수치코드를 사용하여 정압주입시험에 대한 부정류 모의를 수행하였다. 수치모의 결과 주입공에서 매질로 시간별 주입되는 유량은 30분이 경과한 후부터 거의 일정하게 유지되는 양상을 확인할 수 있는데, 현장에서 정압주입시험을 할 때 적어도 30분 이상의 시첩을 실시해야 함을 알 수 있었다. 시험구간에 따른 수리전도도 값은 시험구간의 크기에 상관없이 거의 일정한 값을 보이고 있어, 시험구간의 크기는 정압주입시험에서 크게 유의하지 않아도 된다고 판단된다. 그러나, 시험구간별 주입 압력에 따른 수리전도도 값의 변화를 살펴본 결과, 시험 구간의 크기와 주입 압력 값이 클수록 산출되는 수리전도도 값이 매질의 수리전도도 값과 차이가 나는데, 현장조사에서 시험구간과 주입 압력 값에 대한 고려가 있어야 함을 지시한다. 매질의 수직적 이방성에 따른 모의결과 $K_{zz}$ / $K_{xx}$ and $K_{yy}$ 값이 작아질수록 수리전도도 값이 작아지는데, 현장조사 결과를 해석함에 있어 매질의 수직적 이방성은 주의를 기울여야 한다.

• Journal of Korean Philosophical Society
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• v.131
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• pp.245-272
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• 2014

이 논문은 풍우란(馮友蘭:1895~1990)의 신리학적 철학과학관을 해명하는 것이다. 풍우란은 과학의 역할과 중요성을 긍정하면서도, 철학의 독자적인 역할을 인정한 철학자이다. 그에 따르면 과학은 실제세계에 대한 구체적 적극적 지식을 추구하고, 철학은 '인생경지(경계(境界))의 고양'을 추구하며 나아가 정신의 '자유와 불멸'을 목표로 하는 학문이다. 과학과 철학은 학문의 대상 방법 목표가 상이한 별개의 학문이다. 그는 신실재론의 논리분석방법을 빌어 중국전통철학을 재해석하여 신리학적 철학체계를 수립함으로써 그 혼동을 정리하려했다. 과학은 구체적 객관세계[기(器)] 즉 실제(實際)에 관한 학문이고, 철학은 추상적 보편세계[이(理)] 즉 진제(眞際)에 대한 학문이라는 것이다. 그래서 과학은 구체적인 실제세계에 대한 적극적[긍정적] 지식의 축적을 목표로 하고, 철학은 보편적 세계에 대한 이지적 분석 종합 해석을 목표로 한다. 가장 철학적인 철학인 형이상학은 인생의 경지를 드높이는 것을 추구한다. 철학은 최고의 인생경계 즉, 천지경계(天地境界)의 도달을 목표한다. 이를 위해 철학은 진제에 대한 개념적 논리적 분석을 통해 실제를 초월하는 네 가지 형이상학적 관념을 얻어 천지경계에 도달할 수 있다. 천지경계에 도달하는 형이상학적 방법은 두 가지이다. 하나는 정(正)의 방법으로 논리분석법인데, 경험에 대해 논리적 분석 종합 해석을 하는 것이다. 다른 하나는 부(負)의 방법으로 중국화(中國畵)의 '홍운탁월(烘雲托月)'처럼 말할 수 없는 것을 말하는(불가사의(不可思議), 불가언설(不可言說)) 방법이다. 형이상학은 이를 통해 인간의 삶에 자유와 불멸을 가져다줄 수 있다. 이런 형이상학적 활동은 과학이 목표로 하지도 않고 할 수도 없다는 것이 풍우란의 견해이다. 이로서 풍우란은 참과 거짓을 밝힐 수 없는 무의미한 명제의 추방을 주장한 논리실증주의와 대립되는 철학관에 도달했다.

• Journal of the Korean Society of Earth Science Education
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• v.15 no.2
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• pp.158-170
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• 2022

The purpose of this study is to understand the characteristics of Aristotle's view of nature that is, the static view of the universe, and find implications for education. Plato sought to interpret the natural world using a rational approach rather than an incomplete observation, in terms of from the perspective of geometry and mathematical regularity, as the best way to understand the world. On the other hand, Aristotle believed that we could understand the world by observing what we see. This world is a static worldview full of the purpose of the individual with a sense of purposive legitimacy. In addition, the natural motion of earthly objects and celestial bodies, which are natural movements towards the world of order, are the original actions. Aristotle thought that, given the opportunity, all natural things would carry out some movement, that is, their natural movement. Above all, the world that Plato and Aristotle built is a static universe. It is possible to fully grasp the world by approaching the objective nature that exists independently of human being with human reason and observation. After all, for Aristotle, like Plato, their belief that the natural world was subject to regular and orderly laws of nature, despite the complexity of what seemed to be an embarrassingly continual change, became the basis of Western thought. Since the universe, the metaphysical perspective of ancient Greece and modern philosophy, relies on the development of a dichotomy of understanding (cutting branches) into what has already been completed or planned, ideal and inevitable, so it is the basis of traditional teaching-learning that does not value learner's opinions.

• Journal of Intelligence and Information Systems
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• v.21 no.1
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• pp.15-28
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• 2015

As personal devices and pervasive technologies for interacting with networked objects continue to proliferate, there is an unprecedented world of scattered pieces of contextualized information available. However, the explosive growth and variety of information ironically lead users and service providers to make poor decision. In this situation, recommender systems may be a valuable alternative for dealing with these information overload. But they failed to utilize various types of contextual information. In this study, we suggest a methodology for context-aware recommender systems based on the concept of contextual boundary. First, as we suggest contextual boundary-based profiling which reflects contextual data with proper interpretation and structure, we attempt to solve complexity problem in context-aware recommender systems. Second, in neighbor formation with contextual information, our methodology can be expected to solve sparsity and cold-start problem in traditional recommender systems. Finally, we suggest a methodology about context support score-based recommendation generation. Consequently, our methodology can be first step for expanding application of researches on recommender systems. Moreover, as we suggest a flexible model with consideration of new technological development, it will show high performance regardless of their domains. Therefore, we expect that marketers or service providers can easily adopt according to their technical support.

• The Journal of Korean Association of Computer Education
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• v.12 no.6
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• pp.33-39
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• 2009

Abstract characteristic of algorithm may disturb improving learners' motivation and learning. Therefore, a design of teaching and learning method requires to minimize the learner's intrinsic cognitive load and to maximize the learning motivation. We developed an algorithm learning program by playing to enhance learning motivation and achievement for vocational high school students. And then, we implemented the developed program in vocational high school classes and analysed the educational effects of the developed program. We found that the developed program was helpful in enhancing learners' learning motivation and achievement level. It means that doing the activities, such as playing games, helps learners to acquire an algorithm concept that has abstract nature and is difficult to understand.

• Journal of the Korea Society of Computer and Information
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• v.20 no.5
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• pp.151-159
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• 2015

The algorithm in computer science includes skills to design a problem solving process for solving problems efficiently and effectively. Therefore all learners who learn computer science have to learn algorithm. Education for algorithm is effective when learners acquire skills to design algorithm as well as ability to use appropriate design skills solving problems. Especially since it is heightened people awareness to cultivating informatics gifted students who have potential of significant impact on society, many studies on how to teach them have been in progress. Therefore in this study we adopted puzzles to help informatics gifted students learn skills to design algorithm and how to use them to solve problems. The results of pre and post test compared to traditional algorithm learning, we identified that puzzled based algorithm learning gave a positive impact to students. Students had various problem solving experience applying algorithm design skills in puzzle based learning. As a result, students of learning and learning transfer has been improved.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.612-620
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• 2019

The increasing use of curved beams in buildings, vehicles, ships, and aircraft has results in considerable effort being directed toward developing an accurate method for analyzing the dynamic behavior of such structures. The stability behavior of elastic curved beams has been the subject of a large number of investigations. Solutions of the relevant differential equations have traditionally been obtained by the standard finite difference. These techniques require a great deal of computer time as the number of discrete nodes becomes relatively large under conditions of complex geometry and loading. One of the efficient procedures for the solution of partial differential equations is the method of differential quadrature. The differential quadrature method(DQM) has been applied to a large number of cases to overcome the difficulties of the complex algorithms of programming for the computer, as well as excessive use of storage due to conditions of complex geometry and loading. In this study, the in-plane extensional vibration for asymmetric curved beams with linearly varying cross-section is analyzed using the DQM. Fundamental frequency parameters are calculated for the member with various parameter ratios, boundary conditions, and opening angles. The results are compared with the result by other methods for cases in which they are available. According to the analysis of the solutions, the DQM, used only a limited number of grid points, gives results which agree very well with the exact ones.

• Cartoon and Animation Studies
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• s.41
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• pp.407-427
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• 2015

This thesis is research about the development and application of the panorama image in contemporary artwork, focusing on sculpture and installation. The samples of artworks are a selection of representatives from numerous examples of works that cannot be introduced without exceeding a reasonable scope of the thesis. A brief outline of the historical concepts of the perspective will describe the development of the panorama in itself. Some technical explanations and the practical use of the panorama with its link to 3-dimensional applications should bridge the explanation gap between the 2nd and 3rd dimensional usage of the panorama in contemporary artwork. Furthermore, some philosophical statements are proposed in the discussion. One of the main interests and initial motivation of this study was my personal believe that there is always a relationship between social philosophical values and the way a society sees or encounters visual structures. In other words the contemporary understanding of space and perspective is mirroring the actual zeitgeist and creates an exemplary visual aesthetics.