• KIEAE Journal
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• 제10권2호
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• pp.63-69
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• 2010

Diverse problems in wind environment has occurred through rapid urbanization and growth of high-rise building numbers, This study aims to propose the CFD (Computational Fluid Dynamics) simulation method and evaluation standard of wind environment in site planning of high rise apartment housing. The CFD simulation method proposed in this study is not existing detail simulation, but it is the method that a designer can correct and develop the design through immediate evaluation of design options in concept design phase. Therefore, the proposed CFD simulation method of wind environment in this study uses the BIM based CFD tool in which the 3D model in concept design phase can be used as for the CFD simulation. In this paper, the study examines existing evaluation standards of comfortableness level in wind environment for pedestrian near buildings, and selects new evaluation method which is possible to apply to the proposed CFD simulation method. In addition, it is to examine calculation time-spending and appropriate mesh division method for finding CFD result which is useful to find the best design options in aspect of wind environment in concept design phase. Furthermore, it proposes the wind environment evaluation method through BIM based CFD simulation.

• 대한기계학회논문집B
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• 제25권12호
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• pp.1793-1801
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• 2001

A study of low NOx atomizer was carried out to reduce nitrogen oxides(NOx) in a liquid fuel burner flame. The basic concept of NOx reduction in this atomizer is the fuel 2-staging combustion which is generated by a single atomizer forming two different stoichiometric flames. Two orifices swirl atomizer was selected and modified to realize this concept, and it was tested to obtain the design process of low NOx atomizer. These experiments were achieved to find out the relationship between the injection pressures and the flow rate, spray angle and drop size of swirl atomizer as well as to confirm the NOx reduction concept in real plant(power boiler). In comparison between experimental and theoretical results, the correct discharge coefficient and spray angle were obtained. In real burning test, NOx reduction rate was reached to above 27% of the case using conventional swirl atomizer.

• Advances in materials Research
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• 제5권2호
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• pp.107-120
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• 2016

The static analysis of the simply supported functionally graded plate under transverse load by using a new sinusoidal shear deformation theory based on the neutral surface concept is investigated analytically in the present paper. No transversal shear correction factors are needed because a correct representation of the transversal shearing strain is given. The mechanical properties of the FGM plate are assumed to vary continuously through the thickness according to a power law formulation except Poisson's ratio, which is kept constant. The equilibrium and stability equations are derived by employing the principle of virtual work. Results are provided for thick to thin plates and for different values of the gradient index k, which subjected to sinusoidal or uniformly distributed lateral loads. The accuracy of the present results is verified by comparing it with finite element solution. From the obtained results, it can be concluded that the proposed theory is accurate and efficient in predicting the displacements and stresses of functionally graded plates.

• 한국수학교육학회지시리즈A:수학교육
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• 제40권2호
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• pp.241-252
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• 2001

Many high school students are having difficulties for studying advanced mathematics concepts. It is more complicated than in junior high school and they are losing interest and confidence. In this paper, advanced mathematics concepts are not just basic concepts such as natural numbers, fractions or figures that can be learned through life experience but concepts that are including variables, functions, sets, tangents and limits are more abstract and formal. For the students to understand these ideas is too heavy a burden and so many of the students concentrate their efforts on just memorizing and not understanding. It is necessary to search for a meaningful method of teaching for advanced mathematics that covers deductive methods and symbols. High school teachers are always asking themselves the following question, “How do we help the students to understand the concept clearly and instruct it in a meaningful way?” As a solution we propose the followings : I. To ensure they have the right understanding of concept image involved in the concept definition. II. Put emphasis on the process of making mental representations and the role of intuition. III. To instruct students and understand them as having many chance of the instructional conversation. In conclusion, we studied the meaningful method of teaching with the theory of Ausubel related to the above proposed methods. To understand advanced mathematics concepts correctly, the mutual understanding of both teachers and students is necessary.

• 대한융합한의학회지
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• 제3권1호
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• pp.15-27
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• 2022

Objectives: This study was conducted to review the overall concept of nutritional evaluation of infants and young children. Methods: Literature search was done to study definition, method and importance of nutritional evaluation of infants and young children. Pubmed and Google scholarship were used in the research. Search words were 'Nutritional evaluation', 'infants' and 'young children'. Results: Nutrition evaluation is mainly used by physical measurement, clinical evaluation, dietary intake survey, and biochemical test depending on the age and disease. The treatment method for 治未病, which is a concept of korean medicine, and 健兒法 for treating the concept of weak children are considered to have very high applicability in solving various problems found through nutrition evaluation in korean medical approach. Conclusion: Infants and children are the fastest growing period of their lives, showing rapid growth in physical, and emotional development along with rapid brain growth. Therefore, inadequate nutrition during this period affects mental and physical growth and development not only during that period but also throughout life. Nutrition evaluation is divided into regular evaluation that includes children in all growing seasons and screening evaluation for problem solving, and follow-up nutritional evaluation that evaluates nutritional status in the long run. For each nutritional evaluation, evaluation is conducted by physical measurement, clinical evaluation, dietary intake survey, and biochemical test. By comprehensively interpreting them, nutritional status is determined. This study provides basic data on the proper nutrition evaluation method to identify and correct nutritional problems such as growth level, nutritional deficiency, and nutritional excess early.

• 한국수학교육학회지시리즈C:초등수학교육
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• 제20권2호
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• pp.163-175
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• 2017

본 연구는 평면 도형의 도형 분류하기 과제를 제시할 때 길이와 각의 표기 여부가 도형의 개념 이해에 어떤 영향을 주는지 알아보는데 목적이 있다. 이를 위해, 초등학교 4학년 학생 33명을 대상으로 분류하기 과제 해결 과정을 Eye-tracker를 통해 녹화하고 정답률과 Gaze Duration을 중심으로 분석하였다. 그 결과, 이등변삼각형과 정삼각형의 분류하기에서는 길이를 제시하였을 때 정답률이 증가하고 Gaze Duration은 감소하였다. 예각삼각형과 둔각삼각형 과제에서도 직각을 표기했을 때 정답률이 증가하고 Gaze Duration이 감소하였다. 이러한 결과로 볼 때, 평면도형을 분류하는 과제를 제시할 때는 길이와 각을 표기하여 학생들이 어림하여 도형을 분류하기 보다는 도형의 개념 이해를 바탕으로 분류하는 것을 측정하는 데 초점을 두어야 할 것이다.

• 구강회복응용과학지
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• 제17권2호
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• pp.107-112
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• 2001

The prosthodontic treatment of severely resorbed edentulous patients has been one of the frustrating areas due to extensive loss of tissues. The integrated neuromuscular balance among tongue, lip, and cheek is compromised. The retention, stability, and support are the three major factors to influence the clinical outcome. Fish described a denture as having three surface, with each surface playing an independent and important role in the over all fit, stability, and comfort of the denture. He recommended that the polished surface should be a series of inclines so that pressure from muscular activity will retain dentures. Within the denture space there is an area that has been termed the neutral zone. The neutral zone is that area in the mouth where, during function, the forces of the tongue pressing outward are neutralized by the forces of the cheeks and lips pressing inward. According to Jacobson and Krol, neuromuscular control interacts to provide retention and the relationship of polished surface of denture base to the surrounding muscular structure of orofacial capsule facilitates the stability and retention. This neutral zone concept has been demonstrated with various modification by a number of authors. The theory used to develop the denture base contours is based on the belief that the muscle should functionally mold not only the border but the entire polished surface. Lott and Walsh reported the clinical success on complete mandibular dentures with application of neutral zone concept. A number of studies demonstrated that denture stability and retention are more dependent on correct position of the teeth and correct contour of external surfaces of the denture in a severely resorbed alveolar ridge. This article presents a prosthodontic approach to treatment of a edentulous patient using neutral zone technique to improve the retention and stability of the prosthesis.

• 한국초등수학교육학회지
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• 제18권2호
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• pp.237-255
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• 2014

본 연구의 목적은 초등학생들의 소수 개념에 대한 이해 정도와 소수 연산에 대한 수행 능력을 분석하여 소수 지도에 대한 교수학적 시사점을 얻고자 함이다. 이를 위해 조사연구를 실시하였고, 156명의 6학년 학생들을 대상으로 하였다. 결과 분석은 각 문항별 정답률과 오류가 많이 발생하는 요소를 살펴보았다. 검사 결과, 초등학생들의 소수 개념과 그 연산에서 85.64%의 정답률을 나타냈고, 소수 개념(89.23%), 덧셈(89.84%), 뺄셈(89.56%) 영역보다 소수의 곱셈(80.73%)과 나눗셈(78.85%) 영역에서 낮은 이해도를 보였다. 소수 개념과 그 연산에 대한 학습이 진행될수록 학습 격차가 더 커진다는 것을 알 수 있었기에 낮은 학년에서부터 점진적으로 학습결손을 줄여주려는 노력이 필요하다. 이에 학습 결손을 해소하기 위한 프로그램이 필요하며, 소수의 교수 학습도 개념과 원리를 중시하는 방향으로 바뀌어야 할 것이다.

• 한국컴퓨터산업학회논문지
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• 제3권7호
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• pp.831-836
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• 2002

인터넷상에는 다양한 정보 자원들이 존재하고 있으며 최근에는 XML에 대한 관심이 날로 증가하고 있다. XML은 정보의 구조를 자유롭게 정의할 수 있기 때문에 동일한 응용영역을 표현하는 문서들은 상호 이질적이므로 문서들의 특성에 맞는 각각의 응용프로그램이 필요하다. 만일, 특정 정보를 표현하는 XML문서에 적용되는 DTD가 개념정보를 포함하고 있다면 문서의 구조에 자유롭게 적용될 수 있으므로 상호 이질적인 문제를 극복할 수 있다. 본 연구에서는 개념정보가 포함된 포괄적 DTD를 자동으로 생성하기 위하여 DTD생성기를 개발하였다. 또한 응용영역을 개념화하여 포괄적 DTD를 생성하는데 사용하였다. 포괄적 DTD는 개념정보를 포함하고 있으므로 동일 응용영역 표현하는 다른 구조의 XML 문서에 모두 적용될 수 있으며, 문서의 유효성을 검증하고, 유연한 응용프로그램의 접근이 가능하게 하였다.