• 한국전산구조공학회논문집
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• 제34권3호
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• pp.167-174
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• 2021

최근 국내 원자력발전소의 격납건물 벽체와 Containment Liner Plate(CLP) 사이에서 다양한 크기의 공극이 발견됨에 따라 원전 격납건물의 보수를 위해 내부 공극의 분포와 크기를 정밀하게 평가할 수 있는 진단기법의 개발이 요구되고 있다. 이에 따라 이 연구에서는 격납건물 벽체에서의 탄성파 전파거동을 계산하는 2차원 유한요소해석 기법을 제시한다. 격납건물 벽체를 기반으로 해석영역을 구성하고 경계면에서의 반사파를 제거하기 위해 수치적 파동흡수 경계층인 perfectly matched layer를 도입하였다. Galerkin 기반 혼합유한요소법을 이용해 2차원 유한영역에서 탄성파 파동방정식의 해를 구하여 충격하중에 대한 격납건물 벽체의 변위와 응력을 계산하였다. 제시한 수치적 기법을 이용하여 격납건물 콘크리트 벽체의 CLP 부착 유무와 공동의 위치 및 크기 변화에 따른 탄성파 전파거동을 살펴보았다. 이 연구의 결과는 원전 격납건물 내부의 공동을 진단하는 탄성파 전체파형 역해석 기법 개발에 활용될 수 있다.

• Structural Engineering and Mechanics
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• 제81권2호
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• pp.243-258
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• 2022

In this paper, tensile behavior of joint filling has been investigated under experimental test and numerical simulation (particle flow code). Two concrete slabs containing semi cylinder hole were prepared. These slabs were attached to each other by glue and one cubic specimen with dimension of 19 cm×15 cm×6 cm was prepared. This sample placed in the universal testing machine where the direct tensile stress can be applied to this specimen by implementing a special type of load transferring device which converts the applied compressive load to that of the tensile during the test. In the present work, two different joint filling thickness i.e., 3 mm and 6 mm were prepared and tested in the laboratory to measure their direct tensile strengths. Concurrent with experimental test, numerical simulation was performed to investigate the effect of hole diameter, length of edge notch, filling thickness and filling length on the tensile behavior of joint filling. Model dimension was 19 cm×15 cm. hole diameter was change in four different values of 2.5 cm, 5 cm, 7.5 cm and 10 cm. glue lengths were different based on the hole diameter, i.e., 12.5 cm for hole diameter of 2.5 cm, 10 cm for hole diameter of 5 cm, 7.5 cm for hole diameter of 7.5 cm and 5 cm for hole diameter of 10 cm. length of edge notch were changed in three different value i.e., 10%, 30% and 50% of glue length. Filling thickness were changed in three different value of 3 mm, 6 mm and 9 mm. Tensile strengths of glue and concrete were 2.37 MPa and 6.4 MPa, respectively. The load was applied at a constant rate of 1 kg/s. Results shows that hole diameter, length of edge notch, filling thickness and filling length have important effect on the tensile behavior of joint filling. In fixed glue thinks and fixed joint length, the tensile strength was decreased by increasing the hole diameter. Comparing the results showed that the strength, failure mechanism and fracture patterns obtained numerically and experimentally were similar for both cases.

• 한국멀티미디어학회논문지
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• 제11권2호
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• pp.206-213
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• 2008

애니메이션에는 다양한 연속 이미지로 구성되는 형태와 배경이 있다. 형태로 인식되는 캐릭터가 배경이미지 보다 가치와 의미가 있기에 많은 문헌 연구들이 발견되고 있다. 그러나 배경이미지도 애니메이션을 완성 하는데 중요한 요소임에 틀림없지만. 실제로는 배경이미지에 대한 학문적 연구 결과가 발견되지 않고 있다. 배경이미지는 환경과 분위기를 의미하며 이야기가 일어나는 장소를 설명하므로 캐릭터가 움직이고 말하며 자신을 표현하는 곳이다. 본 연구를 통해 애니메이션의 지적 경계를 확충하는 학문적 노력의 일환으로 배경이미지에 대한 의미 있는 연구와 제안이 될 것이다. 연구의 목적은 배경이미지에 대한 구분을 세가지 요소로 나누고 이를 회화적 카메라 기법적으로 나타낸다. 이를 위해 인지심리학과 회화와 카메라에 대한 기본이론이 활용되어 빈도, 활용, 사실성, 정보량, 투시도, 역할 등을 분석한다. 본 연구는 위의 주제를 통해 배경이미지의 시각적 구분하여 애니메이션 제작과 연구에 기초적 이론을 제공한다.

• 한국산학기술학회논문지
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• 제19권3호
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• pp.130-140
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• 2018

U형 강재보를 근간으로 콘크리트 슬래브와 합성을 위하여 A형의 덮개형 강재앵커를 검토하여 AU합성보를 연구하였다. 이는 노출형의 H형강 강재보에 비해 내부 평면의 자율성을 높일 수 있고 공기 단축과 더불어 층고 절감이 가능하며 튜브구조로서 내부에 콘크리틀 충전하여 휨 강도과 휨 강성를 높였다. 본 연구에서는 AU합성보의 휨실험을 통해 성능을 평가하였다. 실험 결과, 하중 초기에 선형적으로 하중이 증가하면서 콘크리트 슬래브의 파괴에 의해 최대 강도에 도달하고 최대 내력의 85% 이상을 발휘하며 연성적 거동을 하였다. 또한, 덮개형 강재앵커를 통해 합성효과를 발휘하였으며 모든 실험체가 최대 내력에 도달할 때까지 완전 합성거동으로 안정적이었다. 그리고 U형 단면의 강판 두께를 증가시켰을 경우에도 휨 강도와 휨 강성이 증가하였고, U형 단면의 하부에 고강도 강판을 용접 부착하였을 경우에도 성능이 개선되었다. AU합성보의 휨강도는 건축구조기준에 따라 제안된 휨 강도식을 적용할 수 있을 것으로 판단되었다.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제21권3호
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• pp.69-77
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• 2015

Purpose: Under a trend of hospitals that repeated expansion in line with fast increasing factors of medical demands in the past, medical buildings where clinic businesses have regularly gathered in one building have exponentially increased since separation of prescribing and dispensing in 2000. Thus, this study aims at analyzing characteristics of architectural plan of the current medical buildings, identifying strengths and weaknesses through Post Occupancy Evaluation and suggesting an architectural planning method of medical buildings to be planned in the future. Methods: Scope of study has been limited to 23 medical buildings that are registered in the building register as medical buildings out of the Class 1 neighborhood facilities build as 5 floors or more in Cheongju region since 2000 and being actually used for the usage. Study method is to define concepts of the medical buildings through literature review and advanced researches, analyze characteristics of architectural plan through drawing analysis and site survey. Results: General characteristics of architectural plans for the medical buildings in Cheongju have been analyzed. There are the most frequencies in general commercial area and semi-residential area, most of them are reinforced concrete structure and the Class 1 neighborhood facilities. Average land area is $482.68m^2$, gross floor area $3720.8m^2$, the number of underground floors level 1.16, the number of floors level 7.76, total number of floors 8.92, the building-to-land ratio 67.28%, floor area ratio 452.6%, height 31.44m, and the number of parked vehicles 24.16. Implications: This research will contribute to the establishment of the planning methods which increase the quality of Medical Buildings in Cheongju.

• 한국강구조학회 논문집
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• 제18권4호
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• pp.491-502
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• 2006

본 논문은 중력하중의 지배를 받는 CFT기둥-RC 무량판 접합부의 실물대 실험결과를 요약한 것이다. CFT구조는 여러 가지 구조및 시공상의 장점으로 인하여 국내 건설 현장에서 상대적으로 짧은 시간에 폭넓게 수용되고 있다. 주차장 용도로 주로 사용되는 지하층은 철근콘크리트 무량판으로 시공하여 경제성을 도모하는 것이 국내에서 일반적으로 요구되는 시공관행이다. 그러나 CFT기둥-R C 무량판 접합부의 효율적인 디테일은 아직 국내 외적으로 제시된 바가 없어서 이 분야의 연구가 매우 필요한 실정이다. 현장 시공시 경제성을 극대화할 수 있는 몇 가지 전략을 기초로 해서, 여러가지 접합 상세를 제안하였고 실험을 통하여 검증하엿다. 실험결과 본 연구에서 제시된 CFT기둥-RC 무량판 접합 상세의 펀칭강도 및 강성이 RC 무량판 접합부와 동등하거나 이를 상회하는 것을 확인할 수 있었다. CFT기둥-RC 무량판 접합부의 초기 탄성거동에서 펀칭파괴이후 휨철근의 국부 현수작용에 이르기까지의 모델링 방안을 제시하고 본 연구의 실험결과를 기초로 5개의 모델링 변수를 캘리브레이션하였다. 또한 무량판구조의 연쇄붕괴방지 설계에 본 연구의 결과를 응용하는 방안을 사례를 통하여 예시하였다.

• Journal of Community Nutrition
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• 제3권2호
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• pp.103-109
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• 2001

With a continuous and steep increase in life expectancies, Korean society is expected to enter the aged society by year 2020. And as the number of elderly increases, the burden of medical and health care expenses for them becomes greater in every developed society. Hence, the preventive approach for chronic degenerative diseases remains to be the best solution for the above-mentioned problem and warranting optimal nutrition would be one of the most important approaches. We performed a nutrition survey on 585 older adults of 50 years of age and older, residing in 3 metropolitan areas including Daejun, Daeku and Kwangju. Anthropometry, including body composition analysis based on the bioelectrical impedance analysis using InBody 3.0 and dietary intake survey by semi-quantitative flood frequency questionnaires, were used in collecting data. As one of the most important factors affecting the health and nutritional status of the elderly, we focused on living arrangements. Analyses were performed on the data from 550 subjects only, after excluding statistical outliers. Three hundred and sixty-eight of them(66.9%) were female and the number of elderly(65 years of age and older) was 485. According to the statistical analyses, the female elderly were more vulnerable to malnutrition than the male elderly. And the older they befame, the less adequate they were in nutrient intake. In addition to this, the elderly living alone showed the poorest patterns of nutrient intake and anthropometry. Although the exact effect of living alone could differ among different sex-age groups, the fact that the elderly living alone is vulnerable to malnutrition would remain concrete. This raises the utmost necessity of nutrition intervention to be devised and directed to the targeted population, namely the living-alone elderly from the government level. The intervention may include nutrition education, nutrition counseling and support In forms of meal service by networking the efforts of central as well as local governments to ensure the good health of the Korean elderly.

• Structural Engineering and Mechanics
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• 제58권2호
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• pp.277-300
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• 2016

Cold-formed steel (CFS) sections are becoming an increasingly popular solution for constructing floors in residential, healthcare and education buildings. Their reduced weight, however, makes them prone to excessive vibrations, increasing the need for accurate prediction of CFS floor modal properties. By combining experimental modal analysis of a full-scale CFS framed building and its floors and their numerical finite element (FE) modelling this paper demonstrates that the existing methods (based on the best engineering judgement) for predicting CFS floor modal properties are unreliable. They can yield over 40% difference between the predicted and measured natural frequencies for important modes of vibration. This is because the methods were adopted from other floor types (e.g., timber or standard steel-concrete composite floors) and do not take into account specific features of CFS floors. Using the adjusted and then updated FE model, featuring semi-rigid connections led to markedly improved results. The first four measured and calculated CFS floor natural frequencies matched exactly and all relevant modal assurance criterion (MAC) values were above 90%. The introduction of flexible supports and more realistic modelling of the floor boundary conditions, as well as non-structural $fa{\c{c}}ade$ walls, proved to be crucial in the development of the new more successful modelling strategy. The process used to develop 10 identified and experimentally verified FE modelling parameters is based on published information and parameter adjustment resulting from FE model updating. This can be utilised for future design of similar lightweight steel floors in prefabricated buildings when checking their vibration serviceability, likely to be their governing design criterion.

• 대한지구과학교육학회지
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• 제6권3호
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• pp.174-184
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• 2013

The purpose of this study was to investigate the awareness of elementary school teachers on the socio-scientific issues. Fukushima Nuclear Power Plant Accident was used by concrete issue connected with SSI for this study. Participants in this study were twelve elementary school teachers studying at K University Graduate School of Education, located in the central region, who underwent a semi-structured interview. The study method was the phenomenological research method which is one of the qualitative research methods, and the interview papers had been examined by three scientific experts. As a result of the study, it was divided into twenty six themes, eight theme clusters, and two categories, and considered the thoughts on the Fukushima nuclear power plant accident, its influence on Korea, the relationship between science and society as a result of the Fukushima nuclear power plant accident, interested in social issues related to science, application in class, response from students and the influence on students. Teachers had a general understanding of science-related social issues, but did not have much interest in the subject. However, they mentioned that to apply the issues in the curriculum would have a positive influence and encourage scientific motivation in students and, furthermore, helped them to develop the awareness of science in their surroundings. A greater interest in socio-scientific issues need to require from teachers and, through including these issues in the curriculum, we should have positive influence in developing science education.

• Ocean Systems Engineering
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• 제3권1호
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• pp.35-53
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• 2013

In this study, a hybrid floating structure with cylinder was introduced to reduce the hydrodynamic motions of the pontoon type. The hybrid floating structure is composed of cylinders and semi-opened side sections to penetrate the wave impact energy. In order to exactly investigate the hydrodynamic motions and structural behavior of the hybrid floating structure under the wave loadings, integrated analysis of hydrodynamic and structural behavior were carried out on the hybrid floating structure. Firstly, the hydrodynamic analyses were performed on the hybrid and pontoon models. Then, the wave-induced hydrodynamic pressures resulting from hydrodynamic analysis were directly mapped to the structural analysis model. And, finally, the structural analyses were carried out on the hybrid and pontoon models. As a result of this study, it was learned that the hybrid model of this study was showed to have more favorable hydrodynamic motions than the pontoon model. The surge motion was indicated even smaller motion at all over wave periods from 4.0 to 10.0 sec, and the heave and pitch motions indicated smaller motions beyond its wave period of 6.5 sec. However, the hybrid model was shown more unfavorable structural behavior than the pontoon model. High concentrated stress occurred at the bottom slab of the bow and stern part where the cylinder wall was connected to the bottom slab. Also, the hybrid model behaved with the elastic body motion due to weak stiffness of floating body and caused a large stress variation at the pure slab section between the cylinder walls. Hence, in order to overcome these problems, some alternatives which could be easily obtained from the simple modification of structural details were proposed.