• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.606-609
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• 2008

Traditionally, the feasibility of the private investment is determined by NPV(Net Presented Value) based on DCF(Discounted Cash Flow) and the volume of government's subsidiary without quantifying the effect of overturn share ratio and MRG(Minimum Revenue Guarantee), these variables which can seriously effect on the economic feasibility. One of the most important reasons why these variables are not underestimated is that the quantifying methods are insufficiently or so complicatedly studied to apply practically the real project. Therefore, this study suggests the modified binominal option model to estimate the overturn share ratio and MRG and estimates how much these variables impact the private investment. Also, these results are helpful to estimate how much the government's subsidiary can be reduced.

• Applied Microscopy
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• v.33 no.3
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• pp.187-193
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• 2003

When electron microscope images and selected area diffraction patterns of crystalline materials are being compared, it is important to know for the rotation of the diffraction pattern with respect to the image caused by the magnetic lens in the Electron Microscope. A well-known method to determine this rotation is to use a test crystal of $MoO_3$. But this method of determination of the rotation angle contains an uncertainty of $180^{\circ}$. Thus one has to devise another way to eliminate this uncertainty. In this paper we present a new and simple method of determining this rotation without any complexity. The method involves a process of obtaining LACBED patterns of crystalline materials. For the J2010 electron microscope, the rotation is determined to be $180^{\circ}$ and this angle remains unchanged for changing of the magnification and the camera length.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.1
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• pp.65-69
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• 2008

Purpose: To develop a dot sight device for a sighting shot using the doublet reflector. Methods: We designed the singlet reflector and the doublet reflector by Sigma 2000 program and compared the one to the other. Results: In analysis of finite ray aberration, we could confirm that it has the effective field of view with the free-parallax which is 3.3 times wider than the existing dot sight device using the singlet reflector. If you use the doublet reflector, the central thickness of optical system become more than two times bigger than the existing one. As a result, when the image of a target object is made on the observer's retina, if you make the first side's radius of curvature equal with the second one as the case of the singlet reflector, changes in magnification are appeared. To conquer this problem, we had to make be satisfied with the afocal condition in the case of doublet reflector. Conclusions: we could develop the dot sight device for a sighting shot using the doublet reflector which has the effective field of view with the free-parallax which is 3.3 times wider than the existing dot sight device using the singlet reflector.

• Journal of the Korea Concrete Institute
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• v.14 no.6
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• pp.982-988
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• 2002

Current design equations for shear strength of reinforced concrete columns generally overestimate the shear strength contribution by the circular transverse reinforcement. This is due to the simplification of the discrete distribution of the reinforcement to the continuous one and the imprudent application of the classical truss model to the circular section, which is different in shear-resisting mechanism from the rectangular section. This study presents a rational model for the prediction of shear strength contribution by the circular transverse reinforcement considering the starting location of a diagonal crack, the number of transverse reinforcing bars crossing the main crack and the geometrical strength component of the transverse resistance. It was found that, for lower amount transverse reinforcement, the crack starting point and the number of crack crossing bars greatly influence the shear-resisting capacity. Proposed model leads to a reliable design equation which is derived using a linear regression method and is in good agreement with the lower bound of exact strength curve.

• Korean Journal of Agricultural Science
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• v.9 no.2
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• pp.591-595
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• 1982

In order to know about chemical properties of a commercial organofluoro rodenticide, $Kiratol-F^{(R)}$, this experiment was carried out. Chemicals from different two manufactures were compared with synthetic compound by Gas Chromatograph and NMR-spectrophotometer. The results were as followings; 1. The permitted active ingrdient of Kiratol-F, ${\beta}$-fluoro-ethylacetate, was not identified, but ${\beta}$-fluoroethanol was a new active ingradient. 2. Kiratol-F was a water soluble liquid containing samll amounts of chloroethanol in impurity. 3. Yield of synthetic fluoroethanol was about 50%, but the composition of the reactant was assumed ${\alpha}$- and ${\beta}$-fluoroethanol, and the light condition was better than the dark in yield. 4. It was not become known any breakdown of active ingredient by the different dilutions and time intervals. So, the secondary toxicity of Kiratol-F might be relatively higher than imagination.

• Journal of the Korean Society for Nondestructive Testing
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• v.25 no.2
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• pp.74-80
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• 2005

A new dimension measuring method for the measurement of diameter of an object has been developed using laser triangulation. The 3D data of an object was calculated from the 2 dimensional image information obtained by the laser stripe using the laser triangulation. The system that use existing theory can measure the diameter of hole not only in a normal plane but also ill an incline plane. However, in the existing theory, since the lens with fixed feral length was used, the area of measurement was fixed. The simplest way to solve this problem is to change distance between a CCD camera and object. Other way is to use a zoom lens having variable focal length. In this paper, the zoom lens with variable focal length was used. Therefore, we ran experiment with magnification that is optimized according to size of object using zoom lens with variable focal length.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.156-156
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• 1999

자성박막에 존재하는 자기구역의 형상 및 동력학은, 자성박막의 학문적 연구와 응용기술 개발의 핵심을 제공하는 매우 중요한 분야의 하나로서, 최근 크게 관심이 고조되고 있다. 본 연구에서는 차세대 광자기 재질로 각광받고 있는 Co/Pd 다층박막에서의 자기구역 형상 및 자기구역 동력학을 연구하였다. 전자빔 진공증착 시스템을 사용하여, Co 층의 두께와 Pd층의 두께, 그리고 전체 층수가 변화하는 일련의 Co/Pd 다층박막 시료를 제작하였다. 제작된 모든 시료가 명목두께에 대하여 4%의 정밀도로 제작되었음을 확인하였고, 제작된 시료의 자기 및 광자기 성질은 자기이력곡선 등을 측정하였다. 또한 고성능 광자기 Kerr 현미경 시스템을 이용하여 자성박막에 존재하는 자기구역의 형상 및 자기구역 동력학을 관찰하였다. 이 장비는 1,000배의 배율에서 0.3$\mu\textrm{m}$의 공간분해능을 가지며 실시간 자기구역 영상을 CCD 카메라를 통해 컴퓨터에 저장함으로써, 자지구역 거동현상을 관찰할 수 있다. 자성다층박막에 존재하는 자기구역의 형상을 이론적으로 예측하기 위하여, 다층박막 구조에서의 정자기 에너지를 일반적으로 계산할 수 있는 이론을 유도하였다. 이 이론을 통해 다층박막의 자성층의 두께가 두꺼워짐에 따라, 자기구역의 형상이 단일 자기구역 형상에서 줄무늬 자기구역 형상으로 천이함을 예측할 수 있었고, 이러한 지구구역 천이현상을 Co-Pd 다층박막의 자화역전현상을 연구하였고, 새로운 자구동력학 정량분석기술을 개발하여 Co/Pd 다층박막에 적용함으로써 자화역전의 자구벽 이동속도와 핵형성 확률을 각각 정량적으로 구하였다. 이러한 관찰 및 분석기술을 통하여, Co/Pd 다층박막의 층구조에 따라 대조적인 자화역전현상이 존재함을 관찰하였다. 이러한 대조적인 자화역전현상을 결정짓는 요인을 연구하기 위해서 나노자성학이온을 이용한 자화역전현상을 결정짓는 요인을 연구하기 위해서 나노자성학이온을 이용한 자화역전모델을 개발하였으며, 이를 통하여 자성박막의 거시적 자기성질에 의해 이러한 대조적인 자화역전모델을 개발하였으며, 이를 통하여 자성박막의 거시적 자기성지에 의해 이러한 대조적인 자화역전현상이 결정될 수 있음을 설명하였다. 또한, 미시적 자기이력곡선 측정을 통하여 자성박막구조에 따른 국소적인 구조불균일성을 관찰하였고, 이러한 구조불균일성 또한 대조적인 자화역전현상을 결정하는 큰 요인임을 논의하였다.

• Composites Research
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• v.17 no.3
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• pp.45-50
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• 2004

The dynamic properties of short-fiber reinforced chloroprene rubber with different interphase conditions and fiber contents have been studied as functions of frequency, amplitude and temperature. The loss factor(LF) slightly increased more than 1.33% of strain and the dynamic ratio(DR) rapidly decreased with increasing strain amplitude. The LF rapidly decreased with increasing frequency especially more than 50Hz. The DR showed the lower when it compared to virgin material with increasing frequency. The LF showed the maximum at $65^{\circ}$ and rapidly decreased after that temperature. The DR showed the lower when it compared with virgin rubber with increasing temperature. Generally, the better interphase condition showed the lower LF and DR at the same testing condition. Therefore, the short-fiber reinforced rubber could have the better isolation when the frequency ratio is more than $\sqrt{2}$ compared with frequency ratio less than $\sqrt{2}$.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.327-331
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• 2010

충남 당진에 위치한 1,200만$m^2$의 석문 국가산업단지의 개발에 따라 용수수요는 $5m^3/m^2$/년를 적용하면 6,000만$m^3$/년 정도 예상된다. 충남 서북부의 다른 산업단지에서 요구되는 용수수요로 물 확보가 크게 대두되고 있으며, 석문 담수호가 조성돼 있지만 수질관리와 용수를 위해 자체유역에 추가로 수원을 확보할 필요가 있다. 석문 담수호는 유효저수량 910만 $m^3$, 총저수량 1,461만 $m^3$, 만수위 EL.-1.70 m, 사수위 EL.-3.00 m, 수혜면적 1,546 ha, 유역면적 $252.2km^2$이며, 당진읍의 인구 4만 6천명의 생활용수 회귀수와 유역의 농업용수 회귀수를 고려하여 유입량을 모의하고 담수호의 일별 저수량 변화를 분석한 결과 공업용수를 연간 3,500만 $m^3$ 공급할 수 있으며 2,500만 $m^3$이 부족한 것으로 분석되었다. 또한 상류에 유효저수량 937만 $m^3$, 총저수량 972만 $m^3$, 만수위 EL.86.90 m, 사수위 EL.64.60 m, 수혜면적 1,293.8 ha, 유역면적 $25.9km^2$인 고풍 저수지가 위치하고 있으며, 증고에 의해 총저수량을 1,946만 $m^3$로 증가시켜도 석문 담수호의 용수공급능력은 거의 증가되지 않는 것으로 분석되었다. 고풍저수지의 유역배율이 2배 정도가 돼, 증고에 의한 하류 하천 유량은 거의 증가되지 않는 것으로 분석되었으며, 고풍저수지를 이용한 석문 자체유역의 수원확보는 타당하지 않은 것으로 밝혀졌다. 따라서 다른 수원확보를 위한 면밀한 검토가 절실히 요구된다.

• Journal of Biomedical Engineering Research
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• v.19 no.2
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• pp.113-118
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• 1998

By their rapid and periodic actions, the cilia of the human respiratory tract play an important role in clearing inhaled noxious particles. Based on the automated image-processing technique, we studied the method analyzing ciliary beat frequency (CBF) objectively and quantitatively. Microscopic ciliary images were transformed into digitized gray ones through an image-grabber, and from these we extracted signals for CBF. By means of a FFT, maximum peak frequencies were detected as CBFs in each partitioned block for the entire digitized field. With these CBFs, we composed distribution maps visually showing the spatial distribution of CBFs. Through distribution maps of CBF, the whole aspects of CBF changes for cells and the difference of CBF of neighboring cells can be easily measured and detected. Histogram statistics calculated from the user-defined polygonal window can show the local dominant frequency presumed to be the CBF of a cell or a crust the region includes.