• 센서학회지
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• 제13권5호
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• pp.378-382
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• 2004

A micromachined fluidic structure for the introduction of liquid samples into a chip-based sensor array composed of individually addressable polymeric microbeads has been developed. The structure consists of a separately attached cover glass, a single silicon chip having micromachined channels and microbead storage cavities, and a glass carver. In our sensor array, transduction occurs via colorimetric and fluorescence changes to receptors and indicator molecules that are covalently attached to termination sites on the polymeric microbeads. Data streams are acquired for each of the individual microbeads using a CCD. One of the key parts of the structure is a passive fluid introduction system driven only by capillary force. The velocity of penetration of a horizontal capillary for the device having a rectangular cross section has been derived, and it is quite similar to the Washburn Equation calculated for a pipe with a circular cross section having uniform radius. The test results show that this system is useful in a ${\mu}$-TAS and biomedical applications.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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• pp.676-683
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• 2003

A laboratory experiment using artificial fracture rocks was used to understand the 3-dimensional dispersion of a tracer and the mixing process in a fractured network. In this experiment, 12cm polystyrene foam cubes with two electrodes for monitoring electric conductivity (EC) were used as artificial fractured rocks. Distilled water with 0.5mS/m was used as a tracer in water with 35mS/m and the difference of EC between the tracer and the water was monitored by a multipoint simultaneous measurement system of electrical resistance. The results showed that even if the fracture arrangement pattern was not straight in the direction of the flow, the tracer did not diffuse along individual fractures and an oval tracer plume, which was the distribution of tracer concentrations, tended to be form in the direction of the flow. The vertical cross section of the tracer distribution showed small diffusivity in the vertical direction. The calculated total tracer volume passing through each measurement point in the horizontal cross section showed while that the solute passed through measurement points near the direction of hydraulic gradient and in other directions, the passed tracer volumes were small. Using Peclet number as a criterion, it was found that the mass distribution at the fracture intersection was controlled in the stage of transition between the complete mixing model and the streamline routing model.

• 대한심미치과학회지
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• 제31권2호
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• pp.56-63
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• 2022

하악 4전치 수복은 치아가 작고 공간도 좁아서 지대주 선택에 어려움이 따른다. 치주적으로 좋지 못한 상황에서 치아를 발거하는 경우가 대부분이고, 이러한 경우 치간공극을 크게 열어주는 것이 구강위생 관리 측면에서 유리하다1. 커스텀 지대주로 아무리 작은 직경으로 포스트 부위를 만든다 해도, 스크류가 들어가는 공간 때문에 작은 직경으로 지대주의 포스트 부위를 만드는 것에는 한계가 있다. One body implant2의 경우, post 부위를 넓은 정면으로 설정하는 것 보다는, 보다 d 얇은 측면(90도 회전면)으로 설정하는 것이 치간공극 형성을 위해 유리하다. Internal bone level implant 활용 시 two piece abutment를 활용하는 것 보다, one-piece abutment를 활용한다면 더 효과적으로 치간공극을 위한 공간을 확보할 수 있다.

• Journal of the Korean Wood Science and Technology
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• 제31권5호
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• pp.65-71
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• 2003

본 연구에서는 몇 가지 새로운 집성재 단면구성 방법을 제안하고, 국산 낙엽송과 합판으로 제조된 집성재의 휨시험을 통해 단면 구성에 따른 집성재의 휨성능을 평가 비교하였다. 수평적층(BH), 수직적층(BVN), 수직으로 합판보강된 수직적층(BVV)과 수평으로 합판보강된 수직적층(BVH)의 총 네가지 형태의 단면구성 방법에 대하여 실험을 실시하였다. 파괴모드를 관찰하고, 실험을 통해 얻어진 하중-변형 곡선으로부터 MOR 및 MOE를 계산하여 이를 바탕으로 각 단면구성 방법의 휨성능 개선효과를 비교하였다. MOR의 경우에는 결함의 분산으로 인해 수직적층에서 수평적층에 비해 23% 정도의 개선효과를 얻을 수 있었으나, MOE의 경우에는 거의 유사한 값을 나타내었다. 수평으로 합판보강된 경우에는 상대적으로 휨성능이 약한 합판이 사용됨에 따라 MOE가 15% 정도 감소하였으나, 수직으로 합판보강된 경우에는 합판이 사용되었음에도 불구하고 MOE의 감소 없이 MOR이 개선되는 효과를 나타내었는데 이는 전단보강의 효과로 생각되며 이러한 효과를 파괴모드의 관찰을 통해서도 확인하였다. 이상의 결과로부터 집성보의 단면 구성시 라미나의 적절한 배치 및 전단보강 등을 통하여 전체적인 휨성능을 향상시킬 수 있음을 확인하였다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1991년도 봄 학술발표회 논문집
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• pp.75-80
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• 1991

Results of an experimental investigation of low-rise reinforced concrete shear walls with rectangular cross section under cyclic loads are discussed and evaluated. Two half scale models of test specimens with height to length ratio of 0.75 were experimented. The dimension of all walls is 1500mm wide $\times$ 950 mm high $\times$ 100 mm thick for all specimens and the section of all boundary at both ends is 100 mm $\times$ 200mm. Main variables are : horizontal shear reinforcement ratios and reinforcement details(including crossed diagonal shear reinforcements in SWR2 specimen) In SWR2 specimen, maximum strength and consequently dissipating energy index were 1.15~1.21 and 1.48 times greater than those of SWR1 specimen, respectively.

• 한국구조물진단유지관리공학회 논문집
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• 제26권6호
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• pp.102-111
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• 2022

본 논문의 목적은 팔각형 중공단면 철근콘크리트 교각의 내진성능을 평가하고 축방향철근비가 파괴거동에 미치는 영향을 분석함에 있다. 축소모형 팔각형 중공단면 기둥 실험체 4개를 제작하여 일정한 축력 하에서 반복 횡하중을 가력하는 실험을 수행하였다. 모든 실험체의 횡방향 나선철근 체적비는 0.206%로 일정하고 축방향철근비는 2.36 ~ 4.71%이다. 파괴거동과 내진성능을 분석하였고 겹침이음 실험체를 제외한 3개의 실험체는 최종단계에서 휨-전단 파괴거동을 보였다. 겹침이음 실험체를 제외한 실험결과에서 변위연성도와 누적 에너지소산 능력이 축방향철근비에 반비례하여 감소하는 경향을 나타내었다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.935-940
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• 2006

Numerical methods are developed for solving the elastica and buckling load of cantilever column with constant volume, subjected to a compressive end load. The linear, parabolic and sinusoidal tapers with the regular polygon cross-sections are considered, whose material volume and span length are always held constant. The differential equations governing the elastica of buckled column are derived. The Runge-Kutta method is used to integrate the differential equations, and the Regula-Falsi method is used to determine the horizontal deflection at free end and the buckling load, respectively. The numerical methods developed herein for computing the elastica and the buckling loads of the columns are found to be efficient and reliable.

• 한국산업융합학회 논문집
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• 제6권4호
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• pp.373-378
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• 2003

An experimental investigation was performed to study the characteristics of laminar water flow in a horizontal circular tube by using liquid crystal. A simultaneous measurement technique has been employed to measure the temperature field in a two-dimensional cross section of fluid flow. This study found the temperature distribution for Re =900~1,500 along longitudinal sections and the results appear to be physically reasonable. To determine some characteristics of the laminar flow, 2D PIV technique is employed for temperature measurement and liquid crystal is used for heat transfer experiments in water. The experimental rig was manufactured from an acryle tube. The test tube diameter of 25mm, and a length of 1200mm. The used algorithm is the gray level cross-correlation method by using Kimura et al. in 1986.

• 한국산업융합학회 논문집
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• 제7권1호
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• pp.19-24
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• 2004

An experimental investigation was performed to study the characteristics of laminar water flow in a horizontal circular tube by using liquid crystal. A simultaneous measurement technique has been employed to measure the velocity field in a two-dimensional cross section of fluid flow. This study found the velocity distributions for Re = 1,594 ~ 2,510 along longitudinal sections and the results appear to be physically reasonable. To determine some characteristics of the laminar flow, 2D PIV technique is employed for velocity measurement by using liquid crystal in water. The experimental rig was manufactured from an acryle tube. The test tube diameter of 25mm, and a length of 1200mm. The used algorithm is the gray level cross-correlation method by using Kimura et al. in 1986.

• International Journal of Fluid Machinery and Systems
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• 제4권1호
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• pp.150-160
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• 2011

This study focuses on the Achard turbine, a vertical axis, cross-flow, marine current turbine module. Similar modules can be superposed to form towers. A marine or river hydropower farm consists of a cluster of barges, each gathering several parallel rows of towers, running in stabilized current. Two-dimensional numerical modelling is performed in a horizontal cross-section of all towers, using FLUENT and COMSOL Multiphysics. Numerical models validation with experimental results is performed through the velocity distribution, depicted by Acoustic Doppler Velocimetry, in the wake of the middle turbine within a farm model. As long as the numerical flow in the wake fits the experiments, the numerical results for the power coefficient (turbine efficiency) are trustworthy. The overall farm efficiency, with respect to the spatial arrangement of the towers, was depicted by 2D modelling of the unsteady flow inside the farm, using COMSOL Multiphysics. Rows of overlapping parallel towers ensure the increase of global efficiency of the farm.