• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5A
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• pp.457-465
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• 2009

This study presents a moving least squares (MLS) finite difference method for solving elastic crack problems with stress singularity at the crack tip. Near-tip functions are intrinsically employed in the MLS approximation to model near-tip field inducing singularity in stress field. employment of the functions does not lose the merit of the MLS Taylor polynomial approximation which approximates the derivatives of a function without actual differentiating process. In the formulation of crack problem, computational efficiency is considerably improved by taking the strong formulation instead of weak formulation involving time consuming numerical quadrature Difference equations are constructed on the nodes distributed in computational domain. Numerical experiments for crack problems show that the intrinsically enriched MLS finite difference method can sharply capture the singular behavior of near-tip stress and accurately evaluate stress intensity factors.

• Journal of The Korean Association For Science Education
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• v.28 no.2
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• pp.159-168
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• 2008

The purpose of this study was to apply the coteaching to the teaching practice of the student-teachers and identify the distinctive characteristics of the communication processes appeared in coteaching. We developed the semiotic analyzing-frame and observed 7 classes of middle schools where the student-teachers cotaught one or two units. Then we analyzed the communication processes on the view of semiotics. We found three patterns of the communication processes. First, when there was a discontinuous communication between the student-teacher and the students, the communication was restarted by the other student-teacher leading to the complete meaning making. Second, when an insufficient communication took place by the student-teacher using inadequate interpretant, the other student-teacher modified the communication by selecting another interpretant including sufficient meaning towards the object. With this new interpretant, students could refine the imperfect private meanings and eventually establish the more objective meanings. Third, the communication was pre-planned between coteachers to help students understand the contents through the successful translation of interpretants. Coteaching provided positive implications to improve the communication processes in science lesson.

• Korean Journal of Social Welfare
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• v.62 no.2
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• pp.109-134
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• 2010

This study is about the experience of committing suicide's family and the purpose of study is to understand the essential structure of their life experience and to erect the grounded data for the restoration of committing suicide's families. The research was conducted by phenomenological case their family by suicide participated to study data were collected by in-depth interview. The authors interpreted the data in terms of Van-Menen's analysis framework. The result as follows: The essential themes of participant 1 were "digging seclusion site", "whirling around cryptograph" and participant 2 were "resuscitational catastrophe", "sowing seed on destroyed land", and participant 3 were "living Anonymous", "pumping priming water", and participant 4 was "taking on the burden of tragedy", and participant 5 was "stopen life time". The typical theme was "living person's life is died person's remaining category".

• The Journal of the Korea Contents Association
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• v.9 no.1
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• pp.407-416
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• 2009

It is evident that a financial feasibility study based on the economic analysis has been theoretically and practically accepted in the aspect of its adequacy. However, it is not easy to apply in the practical business affairs since there exist some difficulties on the economic analysis and the interpretation of the result because of the difficulty of the estimation of the discount rate. This study aims to suggest a method of the financial feasibility study based on the economic analysis. The results of this study are as follows. First, this study can increase the reliance and adequacy of the economic analysis result by suggesting a method of estimating the discount rate by means of the proxy ${\beta}$ method in the practical way. Second, this study can provide the overall frame of the financial feasibility study based on the economic analysis method (namely, Net Present Value Method internal rate of return, profit index method and payback period method)which use discount rate and cash flow. Third, this study can suggest an practical analysis skill required in each step of the financial feasibility study.

• Journal of the Korean School Mathematics Society
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• v.19 no.4
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• pp.441-457
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• 2016

The purpose of this study is to analyze Korean students' mathematics achievement characteristics and draw implications for better math education in schools through comparing the results of three east Asian top level countries, Korea, Singapore, and Japan in PISA 2012 results. As a results, the rate of correct answers of Korea students was relatively low compared with those of Singapore, but relatively higher than Japan. From the results of effect size, similar results from t-test was discovered. As shown in analysis according to sub-elements in math assessment framework, the Korean students had low effect size in every sub-elements than Singapore. and they had high effect size at most of sub-elements than Japan, except "personal" context. In top performing level(above level 5), the Korean students had high effect size at "quantities" in mathematical contents, and "employ" in mathematical processes compared with Singapore. And they had row effect size at 6 sub-elements compared with Japan.

• Journal of the Korea Society for Simulation
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• v.19 no.3
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• pp.45-54
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• 2010

The inherent complexity of semiconductor fabrication processes makes it hard to solve well-known job scheduling problems in analytical ways, which leads us to rely practically on discrete event modeling simulations to learn the effects of changing the system's parameters. Meanwhile, unpredictable disturbances such as machine failures and maintenance diminish the productivity of semiconductor manufacturing processes with fixed scheduling policies; thus, it is necessary to adapt job scheduling policy in a timely manner in reaction to critical environmental changes (disturbances) in order for the fabrication process to perform optimally. This paper proposes an adaptive job control framework for a wafer fabrication process in a control system theoretical approach and implements it based on a DEVS modeling simulation environment. The proposed framework has the advantages in view of the whole systems understanding and flexibility of applying new rules compared to most ad-hoc software approaches in this field. Furthermore, it is flexible enough to incorporate new job scheduling rules into the existing rule set. Experimental results show that this control framework with adaptive rescheduling outperforms fixed job scheduling algorithms.

• Journal of The Korean Association For Science Education
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• v.28 no.5
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• pp.359-382
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• 2008

There are so many research literatures on conceptual change theory and the nature of concepts such as p-prims, mental model, ontological belief, and cognitive structure. Conceptual change means learning (Vosniadou, 1999; Duit;1999). It is necessary to review and elaborate existing conceptual change theories in order to explain the learning process and its implications. Therefore, we derived from reviewing literatures that learners construct new conceptual structure in response to given contexts at the same time activating their beliefs. We reviewed some mental theories that integrated cognitive and affective components and were based on framework/specific theory or information processing theory. We suggest learners' framework of conceptual structure and conflict model of conceptual structure. We expect to obtain effective ways of science teaching and learning and implications for cognitive conflict and conceptual change from using conceptual structure later.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05b
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• pp.285-290
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• 1998

KALIMER 고속로의 기본 핵연료인 U-l0Zr 핵연료봉의 노내 성능시험을 위해, 러시아의 BR-10 연구용 고속원자로에서 핵연료노내조사 Program이 1997년부터 수행되고 있다. 1 차년도에는 핵연료 시편의 설계 및 제조와 금속합금 핵연료의 균질도, 밀도, 열전도도 등의 노외 특성 시험이 수행되었다. U-l0Zr 핵연료심은 Arc 용해로 제조되었는데, 합금의 구성 원소들은 비교적 균일하게 분포되었다. 핵연료 시편은 2 개가 제작되었는데, BR-10 원자로에서 각각 연소도 1.08 % 및 2.15 %까지 연소된 후, 조사 후 검사가 수행될 것이다. 금속핵연료는 대개 낮은 연소도에서 급격한 변화틀 보이기 때문에, 본 핵연료 노내조사시험 Program의 결과는 금속핵연료봉의 성능해석 모델 개발에 활용될 수 있을 것이다.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.05a
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• pp.617-622
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• 1997

격납건물내 소격실에서의 수소혼합 정도를 파악하고 격실내 균일한 혼합을 좌우하는 인자의 영향을 분석하기 위하여 소규모 혼합실험을 수행했다. 본 연구에서는 해석적으로 수립된 3차원 혼합 모델의 검증을 위하여 3차원 모사가 가능하도록 실험 장치를 구성하였다. 격납용기 내에서 수소 생성의 주원인이 되는 노심으로부터의 수소거동을 분석하기 위한 기초 실험(실험 A)과 안전주입 탱크 격실에서의 수소거동을 분석하기 위해 원형 혼합 chamber를 구상했다. 기초실험 A에서는 혼합 chamber내 축 방향으로 대칭적인 오리피스형 장애물을 설치하고 실험했고 안전주입 탱크 격실을 모사한 실험 B는 영광 3&4호기를 바탕으로 축소시켜 안전주입탱크 격실내 존재하는 두충과 안전 주입 탱크 사이의 틀을 통한 혼합체의 거동을 분석했다. 실험결과 오리피스형 장애물을 설치한 기초실험에서는 원형 띠모양의 장애물이 혼합체의 거동에 큰 영향을 주지 않는 것이 관측됐지만 안전주입탱크격실 실험에서는 격실내 장애물로 존재하는 두충이 혼합체의 거동에 큰 영향을 주는 것이 관측됐다.

• Korean Architects
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• s.557
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• pp.66-79
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• 2015

흔히 예술은 사회적 생산물이라고 말한다. 표층에 들어난 현상의 배후에 그 어떤 것이 존재한다는 것이다. 파도 깊은 곳에 격랑을 일으키는 거대한 물줄기가 있듯이 문화예술의 현상 속에는 시대적 상황과 사회문화적 배경이 존재한다. 하나의 건축물에도 시대적 배경과 담론이 존재하고, 건축사의 과업 속에는 치열한 몸부림이 동반된다. 건축 속에 담긴 심층적 의미를 찾아 떠나는 본 연재는 불후의 건축이 탄생되는 바로 그 순간 그 현장을 탐침하게 된다. 현상의 해석을 위해 때로는 건축주를 찾아 나설 것이며, 때로는 경계를 넘어 미술과 음악같은 인접예술 분야의 현상도 끼어들 것이다. 세잔의 다시점 회화처럼 건축을 다양한 시각에서 바라볼 것이다. 우리 사회에서 건축에 대한 문화적 인식이 높아졌다고는 하나 경직된 틀에서 벗어나지 못하고 있다. 물리적 실체가 아닌 문화적 텍스트로 건축을 이해하는데 본 연재가 도움이 되길 바란다.