• 한국해양공학회지
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• 제13권4호통권35호
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• pp.151-158
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• 1999

A model harbour with Plan scale of $1.08{\times}1.08m$ is built on a tidal tank using a Froude relationship from a real harbour($432{\times}432m$). Velocity components are measured by a ultrasonic velocity meter and flow structure is then predicted using a 2-D depth integrated hydrodynamic model. In the finite difference model implemented in this study, various wall boundary conditions, i.e. no-slip, free-slip, partial-slip and semi-slip are used to represent turbulent diffusion terms, e.g. ${\partial}^2U_{ij}/{\partial}x^2\;or\;{\partial}^2U_{ij}/{\partial}y^2$. These conditions are focused to investigate their influence on the flow structure along the wall and basin of the harbour with aspect ratio of unity, i.e. Length/Breadth. Numerical experiments are compared with the measurements and used to analyse flow patterns in the basin during tidal cycles. It is shown from the results that no-slip closed boundary condition is the most appropriate method with respect to the location of the eddy centre, although the condition underestimates velocity components along the wall.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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• pp.267-270
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• 2004

A silver indium sulfide($AgInS_2$) epilayer was grown by the hot wall epitaxy method, which has not been reported in the literature. The grown $AgInS_2$ epilayer has found to be a chalcopyrite structure and evaluated to be high qualify crystal. From the photocurrent measurement in the temperature range from 30 K to 300 K, the two peaks of A and B were only observed, whereas the three peaks of A, B, and C were seen in the PC spectrum of 10 K. These peaks. are ascribed to the band-to-band transition. The valence band splitting of $AgInS_2$ was investigated by means of the photocurrent measurement. The crystal field splitting, $\ddot{A}cr$, and the spin orbit splitting, $\ddot{A}so$, have been obtained to be 0.150 eV and 0.009 eV at 10 K, respectively. And, the energy band gap at room temperature has been determined to be 1.868 eV. Also, the temperature dependence of the energy band gap, $E_g(T)$, was determined.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2009년 춘계학술대회논문집
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• pp.368-376
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• 2009

Studies on the effect of the wall-ion, wall-water, water-ion and ion-ion interaction on properties of water and ions in nano-channels have been performed through the use of different kinds of ions or different models of potential energy between wall-ion or wall-water. On this paper, we address the effect of water-wall interaction potential on the properties of confined aqueous solution by using the molecular dynamics (MD) simulations. As the interaction potential energies between water and wall we employed the models of the Weeks-Chandler-Andersen (WCA) and Lennard-Jones (LJ). On the MD simulations, 680 water molecules and 20 ions are included between uniformly charged plates that are separated by 2.6 nm. The water molecules are modeled by using the rigid SPC/E model (simple point charge/Extended) and the ions by the charged Lennard-Jones particle model. We compared the results obtained by using WCA potential with those by LJ potential. We also compared the results (e.g. ion density and electro-static potential distributions) in each of the above cases with those provided by solving the Poisson-Boltzmann equation.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.123-124
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• 2007

A silver indium sulfide ($AgInS_2$) epilayer was grown by the hot wall epitaxy method, which has not been reported in the liteniture. The grown $AgInS_2$ epilayer has found to be a chalcopyrite structure and evaluated to be high quality crystal. From the photocurrent measurement in the temperature range from 30 K to 300 K, the two peaks of A and B were only observed, whereas the three peaks of A, B, and C were seen in the PC spectrum of 10 K. These peaks are ascribed to the band-to-band transition. The valence band splitting of $AgInS_2$ was investigated by means of the photocurrent measurement. The temperature dependence of the energy band gap of the $AgInS_2$ obtained from the photocurrent spectrum was well described by the Varshni's relation, $E_g(T)=\;E_g(0)\;eV-(7.78\;{\times}\;10^{-4}\;eV/K)T^2/(T\;+\;116\;K\;K)$. Also, Eg(0) is the energy band gap at 0 K, which is estimated to be 2.036 eV at the valence band state A and 2.186 eV at the valence band state B.

• Journal of the Korean Wood Science and Technology
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• 제44권1호
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• pp.75-84
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• 2016

건물에너지 저감에 효과적으로 기여하는 건축 재료를 이용하는 목조주택을 기반으로 단열 성능이 향상되고 있다. 그러나 고단열 고기밀화로 인한 습기 제어가 어려워져 외벽의 결로 및 곰팡이 발생으로 인하여 성능이 저하될 수 있다. 이에 열 습기 시뮬레이션 프로그램을 이용하여 선정한 5가지 형태의 목조주택 외벽의 열 습기 성능, 결로 발생 및 곰팡이 성장 위험을 평가하였다. 목조주택은 농촌주택 표준설계도 '10과 '14, $2^{{\prime}{\prime}}{\times}6^{{\prime}{\prime}}$형, EIFS 그리고 목조형 패시브 하우스로 선정하였고, 각 벽체 레이어를 구성에 따라 벽 A, B, C, D, E로 구분하였다. 벽체의 열관류율은 각각 0.171, 0.172, 0.221, 0.150, $0.079W/m^2K$이다. 벽 A와 C의 OSB 절대함수량은 기준치 20%를 초과하는 값이 나타났고, 결로 평가를 통하여 단열재 내부 표면에서 겨울철에 결로가 발생할 수 있음을 확인하였다. 벽 D와 E는 외단열 벽체로 다른 벽체에 비하여 함수량 평가와 결로 평가에서 우수한 결과를 보여주었다. 그러나 곰팡이 성장 위험 평가에서 5가지 형태의 벽체 모두 곰팡이 성장 위험성이 있음을 확인하였다. 이에 따라 외벽의 열 습기 성능의 차이는 열적 성능에 의한 발생보다는 레이어 구성에 따른 차이가 발생하는 것으로 판단되었다. 모든 벽체는 비슷한 열적 성능을 가지고 있으나 레이어에 따라 동일한 조건에서의 적합성이 다르게 나타나는 것을 확인하였다.

• 한국동물위생학회지
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• 제27권1호
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• pp.41-52
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• 2004

To establish the differential diagnosis and functional status in ovarian cystic cows, progesterone(P$_4$) and estrogen(E$_2$) level of cystic follicular fluid, ultrasonography for measuring the cystic diameter and thickness of cystic wall, and histological findings were investigated in cystic ovaries from slaughtered Korean native cows. Ovarian follicles were classified as systic if the diameter was greater than 25 mm by ultrasonography. Ovarian cysts < 3 mm of cystic wall thickness, < 10 ng/ml P$_4$ concentration and >10 ng/ml E$_2$ concentration were classified follicular cyst, ovarian cysts 3 mm of cystic wall thickness, 10 ng/ml P$_4$ concentration and <10 ng/ml E$_2$ concentration were classified luteal cyst, and ovarian cysts 3 mm of cystic wall thickness, < 10 ng/ml P$_4$ concentration and <10 ng/ml E$_2$ concentration were classified non-functional ovarian cyst, respectively. Also ovarian cysts were classified 8 types by anatomical and hisctological findings. Ovarian cysts with corpus luteum were 3 of 73 cows and ovarian cysts without corpus luteum were 70 cows. The incidence rates of 8 various types of ovarian cysts were as follows; 2Aa 56.2%, 2Ba 20.5% and 2Ab 15.1%, respectively. The incidence rates of ovarian cysts without corpus luteum were follicular cyst 76.7% and luteal cyst 19.2%. The thickness of cystic wall were lAb 3.9 mm, 2Ab 3.3 mm and 2Bb 3.2 mm, and the cystic fluid P$_4$ concentrations were above 10.0 ng/ml in lAb, 2Ab and 2Bb, respectively. There was significantly correlations between the thickness of cystic wall and cystic fluid P$_4$ concentration in ovarian cysts(p<0.05). The ovarian cyst was classified follicular cysts, luteal cyst and non-functional ovarian cyst by hormone analysis. The luteal cyst was accuratly dignosed by cystic wall thickness. But follicular cysts was misdiagnosed 13 cows of 56 cystic cows. The 13 cystic cows was determined as had non-fuctional ovarian cysts. The cystic fluid P$_4$ concentration was 3.3 ng/ml in follicular ovarian cysts and 30.1 ng/ml luteinized ovarian cysts. There was significantly positive correlations between thickness of cystic wall and serum P$_4$ concentration in follicular(r$^2$ =0.59, p<0.001) and luteal cysts(r$^2$=0.65, p<0.001). These results indicated that ovarian cysts had various stages of degeneration and luteal cyst was accuratly diagnosed measurement of cystic wall thickness by ultrasonography, but follicular cysts was not diagnosed only cystic diameter and cystic wall thickness. In conclusion, it is suggest that ovarian cysts was diagnosed by combination of clinical sign and anatomical cystic features.

• 한국지반신소재학회논문집
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• 제5권3호
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• pp.1-7
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• 2006

1960년대 초 오스트리아에서 개발된 그린월(green wall) 공법은 독립식 콘크리트 보형식의 옹벽으로, 전, 후면 가로보와 세로방향으로 버팀보를 연속적으로 쌓아 올려 내부에 다짐성토를 시행, 구조체가 일체 거동하도록 강성벽체(rigid body)를 형성시키는 옹벽 구조물이다. 국내의 경우, 옹벽 전면 가로보 사이의 공간에 식생이 가능한 친환경적 장점이 있어, 1999년 이후 국내실정을 고려 원지반의 토공량을 최소화할 수 있도록, 쏘일네일 등으로 보강하여 절토 공사현장에 다양하게 적용되고 있는 추세이다. 그러나 그린월 옹벽과 배면에 보강된 쏘일네일이 합벽시공될 경우, 네일에서의 토압분담효과 등에 대한 영향을 고려하지 않고 일반적인 Rankine 토압으로 설계, 시공하여 이중으로 보강공사비용이 투입되고 있는 실정이다. 따라서 본 연구에서는 G$\ddot{a}$ssler(1988)가 제안한 'Two-Body Translation Mechanism(TBTM)'을 이용한 안정해석기법을 수정하여, 네일의 토압 분담효과를 반영할 수 있는 설계기법을 제시하였으며, 본 연구에서 제안한 설계기법을 적용하여 그린월의 보수, 보강공사 비용을 상당부분 감소한 현장설계 사례를 소개하고자 한다. 아울러 본 연구에서 제시한 설계기법을 토대로 계산된 토압을 수치해석 결과와 비교, 검토해 보았다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.985-994
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• 2004

The application of the reinforced retaining wall has increased in the last 10 years in Korea. The height of reinforced wall is generally limited to less than 15m. It has been reported that the reinforced wall higher than 10m should have higher strength reinforcement or should reduce the lateral earth pressure of the reinforced wall to secure the stability of the wall. In this study, the reinforced retaining wall was constructed 14m high, backfilled by a mixture of soil and cement and instrumented on the reinforcement elements. The instrumented reinforced wall was monitored during and after construction. Field monitoring result shows that a backfill by a mixture of soil and cement reduced the tensile stress developed on the reinforcing elements and the reinforced wall backfilled by a mixture of soil and cement performed successful.

• 대한기계학회논문집B
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• 제24권2호
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• pp.224-232
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• 2000

Four turbulent $k-{\varepsilon}$ models (i.e., standard model, modified models with streamline curvature modification and/or preferential dissipation modification) are applied in order to analyze the turbulent flow of wall-attaching offset jet. For numerical convergence, this paper develops a method of slowly increasing the convective effect induced by skew-velocity in skew-upwind scheme (hereafter called Partial Skewupwind Scheme). Even though the method was simple, it was efficient in view of convergent speed, computer memory storage, programming, etc. The numerical results of all models show good prediction in first order calculations (i.e., reattachment length, mean velocity, pressure), while they show some deviations in ·second order (i.e., kinetic energy and its dissipation rate). Like the previous results obtained by upwind scheme, the streamline curvature modification results in better prediction, while the preferential dissipation modification does not.

• 한국결정성장학회지
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• 제14권6호
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• pp.244-252
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• 2004

$CuISe_2$ 단결정 박막은 수평 전기로에서 합성한 $CuInSe_2$ 다결정을 증발원으로하여, hot wall epitaxy(HWE) 방법으로 증발원과 기판(반절연성-GaAs(100))의 온도를 각각 $620^{\circ}C$, $410^{\circ}C$로 고정하여 단결정 박막을 성장하였다. 이때 단결정 박막의 결정성은 광발광 스펙트럼과 이중결정 선 요동곡선(DCRC) 으로 부터 구하였다. Hall 효과는 van der Pauw 방법에 의해 측정되었으며, 293K에서 운반자 농도와 이동도는 각각 $9.62\times10^{16}/\textrm{cm}^3$, 296 $\textrm{cm}^2$/Vㆍs 였다. $CuAlSe_2$/Si(Semi-Insulated) GaAs(100) 단결정 박막의 광흡수와 광전류 spectra를 293k에서 10K까지 측정하였다. 광흡수 스펙트럼으로부터 band gap $E_g$(T)는 Varshni 공식에 따라 계산한 결과 1.1851 eV-($8.99\times10^{-4} eV/K)T^2$/(T+153k)였다. 광전류 스펙트럼으로 부터 Hamilton matrix(Hopfield quasicubic mode)법으로 계산한 결과 crystal field splitting Δcr값이 0.0087eV이며 spin-orbit Δso값은 0.2329 eV임을 확인하였다. 10K일 때 광전류 봉우리들은 n = 1일때 $A_1-, B_1$-와 $C_1$-exciton봉우리임을 알았다.