• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.457-460
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• 1998

단 채널 MOSFET 소자의 드레인 전압-드레인 전류 특성을 예측하기 위해서 caughey-thomas 이동도 모델을 수치적으로 구현하는 방법을 제안한다. 구현된 caughey-thomas 모델의 정확한 특성을 검증하기 위해서 0.5[.mu.m]의 설계규칙을 가즌 ASIC용 공정으로 n-MOSFET과 p-MOSFET을 제작하였다. 전자 및 정공의 포화속도 값이 각각 6.2*10/sup 6/[cm/sec] 과 1.034*10/sup 7/[cm/sec]인 경우에 채널길이가 0.5[.mu.m] 이상인 n-MOSFET과 p-MOSFET의 드레인 전압-드레인 전류특성의 모의실험 결과는 측정값에 비하여 10% 이내의 상대오차를 보였다.

• Clean Technology
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• v.20 no.2
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• pp.166-170
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• 2014

The continuous experiments were carried out using fixed-bed column packed with strong-acid cation exchange resin for the removal of lithium ions from aqueous solution. The parameters such as bed height, flow rate and inlet concentration were investigated. Breakthrough time ($t_{0.05}$), saturation time ($t_{0.95}$), and total amount of lithium ion removed (mtotal) were obtained from the breakthrough curves. The results showed that $t_{0.05}$ and $t_{0.95}$ decreased with decreasing bed height, and decreased with increasing inlet concentration and flow rate. mtotal increased with increasing inlet concentration and bed height, but decreased with increasing flow rate. Thomas model and Yoon-Nelson model equations were applied to the experimental data, the results showed that the breakthrough data gave a good fit to Thomas model equation.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.709-710
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• 2002

Cancer angiogenesis is simulated using a two dimensional model. Governing equation of angiogenesis is a TAE (Tumor angiogenesis factor) conservation equation in time and space. A stochastic process model is utilized to simulate vessel formation, proliferation, and migration to a cancer pellet. Numerical results are presented especially in case of growing cancer.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.5
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• pp.535-541
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• 2005

Peat humin(p-Humin) extracted from Canadian Sphagnum peat moss was packed in a column and removal of heavy metal ions such as Cd, Cu and Pb from aqueous solution under flow conditions was studied. The metal ions were removed not only from single-element solutions but also from a multi-metal solution. Column kinetics for metal removal were described by the Thomas model. For single-component metal solutions, the maximum adsorption capacities of the p-Humin for Pb, Cu and Cd were 138.8, 44.66 and 41.61 mg/g, respectively. The results of multi-component competitive adsorption showed that adsorption affinity was in the order of Pb $\gg$ Cu > Cd. The adsorbed metal ions were easily deserted from the p-Humin with 0.05 N $HNO_3$ solution. It is apparent that 95% of the heavy metal ions were recovered from the saturated column. This investigation provides possibility to clean up heavy-metal contaminated waste waters by using the natural biomass, p-Humin as an environmentally friendly and cost-effective new biosorbents.

• Geotechnical Engineering
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• v.8 no.1
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• pp.81-102
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• 1992

Landslides on hillside slopes with shallow soil cover over a sloping bedrock are frequently caused by increases in porewater pressures following of heavy rainfall and it is one of the most important factors of assessing the risk of landslide to predict the groundwater level fluctuations in hillslopes. This paper presents the comparative study of three unsaturated flow models developed by Sloan et al., Reddi, L.N., and Thomas, H.A., Jr., respectively, which are used to predict the increase of groundwater levels in hillside slopes. The parametric study for each of models is also presented. The Kinematic Storage Model(KSM) developed by Sloan et at. is utilized to predict the saturated groundwater flow. They are applied to the two sites in Korea so as to examine the possibility of use in the groundwater flow model. The results show that two unsaturated models developed by Sloan et al. and Reddi, L. N. are largely affected by the uncertain parameters like saturated permeability and saturated water content : the abed model has the potential of use in unsaturated flow model with the optimal estimates of model parameters utilizing available optimization techniques. And it is also found that the KSM must be modified to account for the time delay effect in the saturated zone. The results of this paper are able to be utilized in developing the predictive model of groan dwater level fluctuations in a hillslope.

• Proceedings of the KAIS Fall Conference
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• 2012.05a
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• pp.122-124
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• 2012

한국을 찾는 외국인에게 한류는 무형의 문화상품이며 새로운 자극을 원하는 외국인 수용자에게 지속적인 한류상품 개발이 요구되고 있다. 화장품 산업이 한류라는 문화적 현상을 긍정적으로 수용하고 산업적으로 재해석하여 해외 현지에 성공적으로 안착하는 과정을 살펴보고 방향성을 진단하려는 의도에서 시작되었다. 한류가 화장품 산업에 미치는 영향과 실제로 구현되는 사례를 통하여 한류의 모델이 브랜드 확장의 한 축으로 영향력을 보여주고 브랜드 자산을 키우고 있다는 것을 알 수 있다. 문화가 성공적으로 입성한 곳에 산업이 무혈입성하는 과정을 화장품 산업은 선두에서 보여주고 있다.

• Digital Contents
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• no.5 s.96
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• pp.30-31
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• 2001

'사람들은 인터넷상의 콘텐츠에 대한 최초의 모델인 거대한 수평 포털들이 미래의 열쇠라고 생각하지만, 사실은 그렇지 않다.'고 internet.com Corporation의 사장겸 CEO인 Alan M. Meckler는 말했다. '나의 이론, 나는 이것이 입증되고 있는 중이라고 생각하는데, 어쨌든 내 이론은 인터넷 전체가 수직의 웹사이트들로 이동하고 있다는 것이다. 인터넷은 매우 크고 매우 넓게 정렬되고 있으며 지수함수적으로 증가하고 있다. 이를 따라잡을 수평 웹사이트는 존재하지 않는다. 그러므로 여러분은 수직으로 가야만 한다. 이는 거대한 도서관과 같다. 도서관은 주제 영역들이 있는데, 바로 그런 식으로 인터넷이 펼쳐지고 있는 것이다.'

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.5
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• pp.837-846
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• 2004

This paper presents a screening technique for greatly reducing the computation involved in determining the optimal location and types of Flexible AC Transmission System (FACTS) devices in a large power system. The first-order sensitivities of the generation cost for various FACTS devices are derived. This technique requires solving only one optimal power flow (OPF) to obtain sensitivities with respect to FACTS device control variables for every transmission line To implement a sensitivity-based screening technique, we used a new UPFC model, which consists of an ideal transformer with a complex turns ratio and a variable shunt admittance. A S-bus system based on the IEEE 14-bus system was used to illustrate the technique.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.4
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• pp.1-8
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• 2013

Constitutive modeling of constituent materials is very important for reinforced concrete (RC) frames. Cyclic constitutive behavior of unconfined concrete, confined concrete and reinforcing steel should be well defined in fiber-based discretization of RC sections. This study performs nonlinear dynamic analyses of RC frame structures to investigate the sensitivity of seismic behavior of such frames to different constitutive models of constituent materials. The study specifically attempts to examine confinement effects in concrete modeling and degrading effects in steel modeling, which substantially affects the monotonic, cyclic and seismic responses of RC members and frames. Based on the system level analysis, it is shown that the response of non-ductile frames is less sensitive to confined concrete models while the modeling of reinforcing steel is quite influential to the inelastic response of both non-ductile and ductile frames.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.9
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• pp.505-512
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• 2017

The adsorption characteristics of Sr ion in aqueous solution was examined using zeolite NaA powder (Z-PA) and pellets (Z-BA). In batch experiment, the adsorption of Sr ions by Z-BA and Z-PA was well expressed by pseudo-second-order kinetic model than psedo-first-order kinetic model. Experimental isotherm results was well fitted to Langmuir isotherm model and the maximum adsorption capacities obtained from Langmuir isotherm model were 233.32 mg/g for Z-PA and 164.60 mg/g for Z-BA, respectively. The continuous experiment results showed that the total Sr ion uptake (q) increased, but the breakthrough time, effluent volume ($V_{eff}$) and total removal (R) of Sr ion decreased with the Sr ion concentration. The breakthrough curves obtained from the experiment was modeled by Thomas model.