• 한국기계기술학회지
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• 제13권2호
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• pp.101-106
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• 2011

In this study, the velocity distribution according to upper side coner shape of underwater construction with rectangular cylinder was measured with PIV method and the wake flow characteristics was considered. According to the coner shape, the flow pattern of wake flow was also differed greatly and the step-shaped coner of cut-off ratio B/H=0.06 was similar in the slope shape in result.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 춘계학술대회 논문집
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• pp.490-496
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• 1995

A four-legged mobile robot can move on the plain terrain with mobility and stability, but if there exist any obstacles on the terrain of the motion direction, it takes extra times for a mobile robot to cross those obstacles and the stability should be considered during motion. The main objevtive is the study of a quadruped which can cross obstacles with better mobility, stability and fuel economy than any other wheeled or tracked vehicles. Vertical step, isolated wall and ditch are the basic obstacles and by understanding those three cases perfectly, a quadruped can move on any mixed rough terrain as 4-legged animal moves. Each leg of a determine the crossing capability in a static analysis. A quadruped can be simplified with links and joints. By applying the research method, a quadruped can determine the control procedures as soon as it receives the terrain informations from scanner and finally can be moved as animals move with mobility and stability.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.118-119
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• 2009

This paper presents the feature profile evolution silicon deep trench etching, which is very crucial for the commercial wafer process application. The silicon deep trenches were etched with the SF6 gas & Hbr gas based process recipe. The optimized silicon deep trench process resulted in vertical profiles (87o~90o) with loading effect of < 1%. The process recipes were developed for the silicon deep trench etching applications. This scheme provides vertically profiles without notching of top corner was observed. In this study, the production of SF6 gas based silicon deep trench etch process much more strongly than expected on the basis of Hbr gas trench process that have been investigated by scanning electron microscope (SEM). Based on the test results, it is concluded that the silicon deep trench etching shows the sufficient profile for practical MOS FET silicon deep trench technology process.

• 한국주거학회논문집
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• 제23권2호
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• pp.25-36
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• 2012

The purpose of this study is to find out the commercialization characteristics of 2nd class residential district in innercity railway station area as basic research to protect urban residential area against the pressure of commercialization. Through the research that are based on literature, field survey and urban planning map, it analysed the commercialization characteristic of selected three sites under similar urban condition; to be a nearby subway station and to be a famous commercial street in site, etc. The consequences of this study are summarized as follows; First it finds the commercialized lots in all blocks that adjoin blocks of upper class zoning. Second it is in inverse proportion between the commercialization of lots and the distance from subway station to residential block. Third, the corner lot of a block and the access road directly connected collector road are very important factors to spread commercialization to residential area. Finally, it finds the difference of the commercialization degree of 2nd class residential zone according to arrange main commercial street and the 2nd class residential block; vertical arrangement and horizontal arrangement.

• 대한전자공학회논문지
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• 제26권4호
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• pp.88-97
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• 1989

본 논문에서 제안하는 switch-box 배선기는 greedy poly-jog 배선기와 via 최소화기로 나누어진다. Greedy poly-jog 배선기는 Luk의 greedy swich-box 배선 알고리듬을 기본으로 하며, 수평track에 metal을 수직track에 poly-silicon을 배선하는 제한을 완화하여 필요한 경우에는 수평 track에 poly-silicon을 배선함으로써 배선영역의 수평track을 증가시키지 않고 배선할 수 있다. Via 최소화기는 배선된 wire의 각 corner를 펴거나 wire 선분을 평행이동하거나 metal을 poly-silicon 및 poly-silicon을 metal로 바꿈으로써 via와 배선길이를 줄이는 과정을 수행한다. 본 배선기는 column 방향으로 배선영역을 scan함으로써 배선을 완료하며, 시간복잡도는 O(M(N+ Nnet)) 이다. 여기서, M, N, Nnet은 각각 배선 column의 수, 배선 row의 수, net의 수이다.

• 한국가스학회지
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• 제12권4호
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• pp.34-40
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• 2008

FEM과 다구찌의 설계기법을 이용하여 헬멧의 주름댐퍼에 걸리는 수직방향 변위량, von Mises 응력, 변형률 에너지를 주름댐퍼의 돌출길이와 두께, 주름댐퍼의 상단코너반경과 하단코너반경의 함수로 각각 분석하였다. 주름댐퍼의 형상에 대한 최적의 설계요소는 헬멧에 전달되는 외부의 충격력에 의해 형성되는 충격에너지를 흡수할 수 있는 감쇠용량, 즉 변형률 에너지를 높여줄 수 있다는 측면에서 대단히 중요하다. 본 연구에서 다구찌 설계법에 기반한 최적설계는 주름댐퍼의 돌출길이 L = 20 mm, 두께 t = 2 mm, 상단코너반경 $R_1=4\;mm$, 하단코너반경 $R_2=3\;mm$로 계산되었다. 주름댐퍼의 설계에 가장 큰 영향을 미치는 핵심요소는 주름댐퍼의 두께와 돌출길이고, 이들 설계요소는 헬멧의 충격에너지 흡수용량을 나타내는 변형률 에너지 증가에 대한 기여도가 높다.

• 대한건축학회논문집:구조계
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• 제35권7호
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• pp.171-178
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• 2019

Auto Climbing Formwork System (ACS) for construction of high-rise building is a construction method for automatically lifting the formwork system supported by the anchor on the pre-constructed concrete wall. It has excellent construction speed and quality, but it has the possibility of structural failure depending on the quality of concrete and also has low economical efficiency due to the use of foreign technology. In order to overcome these problems, this study conducted an optimum design for the development of a new concept of Corner Supported Auto Climbing System (CS-ACS) in conjunction with the development of corner steel-reinforced concrete core wall system. For the design the formwork system, the basic module and structural member compositions were planned, and the structural analysis program was used to analyze the optimum member's cross section and spacing. As a result, the horizontal displacement and the stress of the horizontal members were influenced by the spacing more than the cross-section of the member. On the other hand, vertical members did not affect the displacement and stress of the formwork system. The form tie was very effective in controlling the displacement when adjusting the spacing of the horizontal members, but when the spacing of the form tie is more than 1,500mm, it is analyzed that form tie is yielding in basic module. When the span of the formwork system is more than 30m, it is analyzed that the basic module needs to be changed because of the increase of overall displacement.

• 한국측량학회지
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• 제28권1호
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• pp.153-160
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• 2010

향후 구축될 3차원 수치지도의 정확도 검증을 위해서는 기준점 또는 검사점 역할을 할 수 있는 건물 모서리와 같은 대상점에 대한 정확한 3차원 좌표값이 반드시 필요하다. 건물 모서리 점에 대한 좌표는 GPS를 이용하여 결정한 지상기준점으로부터 거리 또는 각을 이용한 지상측량의 방법으로 결정할 수 있는데, 지상기준점의 오차는 지상측량을 통해서 최종적으로 건물 모서리좌표에 영향을 미치므로 이는 반드시 고려되어야 한다. 본 연구에서는 GPS 등으로 결정한 지상기준정의 오차정보가 지상측량을 통해 최종적인 미지수인 건물 모서리 점의 추정값에 미치는 영향에 대해서 수학적으로 분석하고 시뮬레이션 데이터틀 통해 수치적으로 테스트 했다. 지상기준점의 오차는 수평방향 1-4cm 수직방향 2-8cm에 대해서 각각 테스트 했으며 GPS 위치결정의 특성상 수칙방향의 오차가 수평방향의 오차의 두 배가 되도록 했다. 위치결정을 위한 지상측량 방법은 거리측량을 기준으로 테스트했으며, 추정된 건물 모서리점의 정밀도는 지상기준점의 오차에 거의 선형적으로 비례함을 알 수 있었다. 또한 건물 모서리 점의 최종 추정좌표는 관측장비의 정밀도에 따라 부여한 랜덤오차에 따라 달라지지만 추정 정밀도는 거의 일정함을 알 수 있었다.

• 대한치과보철학회지
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• 제31권4호
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• pp.643-659
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• 1993

This study was performed for the purpose of evaluating the stress distributions around five different types of implants according to their structures. The stress distribution around the surrounding bone was analysed by two-dimensional photoelastic method. Five epoxy resin models were made, and vertical and lateral forces were applied to the models. A circular polariscope was used to record the isochromatic fringes. The results of this study were summerized as follows : 1. Threaded type implants showed more even stress distribution patterns than cylinderical type implants when vertical and lateral forces were applied. 2. The stress concentrated patterns were observed at the neck portion and middle portion of the cylindrical type implants comparing with threaded type implants when vertical force was applied. 3. Model 1 and model 4 which are tthreaded type implants showed similar stress distribution patterns at the middle and apical portions and more stress was concentrated at the neck porion of model 1 comparing with model 4 when vertical force was applied. The stresses around model 1 were more evenly distributed when lateral force was applied. 4. More stress was concentrated at the neck and middle portion of cylindrical type implants than threaded type implants when lateral force was applied. 5. Model 1 showed the most even stress distribution patterns when lateral force was applied and stress distribution did no occured at the apical portion of modedl 2 when lateral force was applied. 6. There were almost no differences in stress concentrated patterns with or without having hollow design. And the stress concentrated patterns were observed at the corner of apex in model 5 which has hollow design when vertical force was applied.

• Journal of Advanced Marine Engineering and Technology
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• 제36권1호
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• pp.94-100
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• 2012

본 연구는 벽면 근처에 놓인 정방형주의 모서리에 수직 분할판을 부착하여 유체력 제어 효과를 양항력 측정실험 및 PIV에 의한 가시화 실험으로 조사한 것이다. 분할판의 폭은 정방형주 폭의 10% 로 했다. 실험변수로서는 수직 분할판의 부착 위치 및 벽면과 사각주 사이의 간격으로 하였다. 정방형주 중심에서 후류방향으로 3.0B(B: 정방형주 한 변 길이) 떨어진 곳에서 와도의 변화가 가장 명확했다. 수직 분할판의 위치 및 유무와 관계없이 간격비 0.4~0.6에서 평균양력계수 및 Strouhal 수의 변곡점이 나타났다. 정방형주 윗면의 뒷 모서리에 수직 분할판을 설치한 경우 항력이 감소하였으며 각 간격비 평균 5.0%의 항력 저감 효과를 얻었다. 정방형주 윗면 박리영역의 크기는 앞쪽 모서리에 수직 분할판을 설치한 경우가 가장 컸고, 원형의 정방형주, 뒷쪽 모서리에 수직 분할판을 설치한 순서로 작았으며, 평균항력계수는 이 박리영역의 크기에 비례했다.