• Proceedings of the KIEE Conference
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• 1997.07c
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• pp.764-766
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• 1997

This paper presents a DSM Monitoring Methodology which is able to evaluate the impact of DSM programs under processing. For an effective assessment of DSM programs, it is foremost necessary to examine the market characteristics on the specific end-use appliance according to the customer's adoption of DSM programs. The Proposed Monitoring system contains a diffusion process of high efficient end-use considering major factors of DSM impact such as, price, price elasticity and lifetime of end-use apparatus or appliance. The case study shows the propriety and necessity of DSM monitoring in order to diagnose the current state and provide a baseline of DSM policy

• Journal of Korea Water Resources Association
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• v.30 no.2
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• pp.119-129
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• 1997

A three-dimensional numerical model for the simulation of meso-scale local circulation is developed and it is applied to the land and sea breezes which take place around Ulsan. The surface temperature and moisture on the land are determined by means of the surface heat budget with a layer of vegetation considered. The vertical diffusion coefficients of momentum, heat and specific humidity at the surface layer are obtained by the lever-2 model of the turbulence closure proposed by Yamada (1982). This model proved to be effective in simulating the structure of the land and sea breezes around Ulsan.

• Journal of Magnetics
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• v.12 no.4
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• pp.152-155
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• 2007

Spin dependent transport was investigated in lateral $Py(Ni_{81}Fe_{19})/Au/Py$ spin valve devices. Clear spin valve effect was observed in conventional four-terminal measurement geometry. Higher resistance was found in antiparallel magnetization field of two Py electrodes which is determined by anisotropy magnetoresistance (AMR) measurements. The rectangular shape of spin signal together with good agreement of switching field convinces observed spin valve signal is resulted from effective spin injection and detection. The magnetoresistance ratio decays exponentially with channel length by which spin diffusion length of Au channel was estimated to be 76 nm.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.5
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• pp.422-430
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• 2001

In the present study, an evaporative generation process of ammonia-water solution film on the vertical plate was analysed. For the utilization of waste heat, hot water of low temperature was used as the heat source. The continuity, momentum, energy and diffusion equations for the solution film and vapor mixture were formulated in integral forms and solved numerically. Counter-current solution-vapor flow resulted in the refrigerant vapor of the higher ammonia concentration than that of co-current flow. Eve the rectification of refrigerant vapor was observed near the inlet of solution film in counter-current flow. For the optimum operation of generator using hot water, numerical experiments, based on the heat exchange and generation efficiencies. revealed the inter-relationships among the Reynolds number of the solution film and hot water, and the length of generator. Enhancement of heat and mass transport in the solution film was found to be very effective for the improvement of generation performance, especially at high solution flow rate.

• Journal of the Korea Society for Simulation
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• v.8 no.2
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• pp.13-28
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• 1999

The main purpose of this paper is to design and implement forest fire information system (FOFIS) for effective prevention of forest fire using GIS, database, 3-D graphics, and simulation techniques. In contrast to conventional fire information systems that are mostly based on the 2-D graphics and analytic modeling approaches, we have proposed the cell-based modeling approaches, i.e., spatial, data, and simulation modeling approaches. The cell-based spatial modeling is proposed by eliminating the cliff effect of the typical elevation model so that it can provide realistic 3-D graphics of the forest fire. The cell-based data modeling of geography, meteorology, and forestry information is also proposed. The cell-based dynamic modeling for forecasting of the fire diffusion is developed using the variable structure modeling techniques. Several simulation tests of FOFIS performed on a sample forest area of Chungdo, Kyungsangbukdo will demonstrate our approaches.

• YAKHAK HOEJI
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• v.47 no.3
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• pp.154-158
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• 2003

Lincomycin, a selective tyrosinase blocker, has been thought to be effective in the treatment of melanogenesis, ephelis, post inflammatory pigmentation, and facial discoloration. In an attempt to develop a transdermal perparation for lincomycin, this study was designed to examine the appropriate contents of various surfactants and ethanol in the cream preparation. Frans type diffusion cell was used to investigate permeation efficiency of the preparation, and lincomycin in the receptor phase was measured by HPLC. After having a 1.5 hrs of leg time, the permeability of lincomycin was rapidly increased by adding surfactants, and varied with different types of surfactants after 10 hrs, the permeability of Brij 56$^{(R)}$ preparation (501.4$\pm$45 $\mu\textrm{g}$/mι) was greater than that either of Labrasol$^{(R)}$ (263.9$\pm$33.7 $\mu\textrm{g}$/mι) or Tween$^{(R)}$20(386.2$\pm$26.7 $\mu\textrm{g}$/mι). Ethanol also increased the permeability of lincomycin.mycin.

• Korean System Dynamics Review
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• v.14 no.4
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• pp.37-62
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• 2013

The purpose of this paper is to find out some clues about effectiveness and implementing timing of the control measures against Foot-and-Mouth Disease (FMD) in Korea. To do that, the case of FMD, which broke out during November 2010 in Korea, is examined and constructed as a system dynamics simulation model. The implications of simulation result are as follows. First of all, it is most effective measure to prevent the movement of vehicle from infected farmhouse to other noninfected farmhouses, which are located far away, in the early stage of FMD diffusion. Secondly, earlier vaccination can be adopted as a reliable means to control the epidemic when FMD spreads widely. Finally, reducing the time to vaccinate the whole noninfected livestock is a little help to restrain the additional infections of FMD.

• Journal of Korean Society for Atmospheric Environment
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• v.6 no.2
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• pp.161-167
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• 1990

The reaction of sulfur dioxide with cupric oxide supported on zeolite was investigated over a temperature range of $250{\sim}450^{{\circ}C$. After the completion of the $SO_2$ removal reaction, the cupric sulfate produced was regenerated to copper by hydrogen or LPG. The experimental results showed that the removal efficiency of $SO_2$ was improved with temperature increase and with $SO_2$ inlet concentration decrease. The reaction of $SO_2$ with CuO/Zeolite was well explained by the shrinking unreacted core model using first order chemical reaction control and diffusion control. THe reaction rate constant and the effective diffusivity were respectively as follows: 1k (cm/s) = 2.519 exp[-10991 (cal/mol)/RT] $De(cm^2/s) = 2.06 \times 10^{-5} exp[-8380 (cal/mol)/RT]$

• Journal of ILASS-Korea
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• v.23 no.1
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• pp.1-8
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• 2018

In this study, the effects of variation in cam phasing and valve lift of exhaust valves by using Cam-in-Cam system on combustion and emission characteristics for diesel engine were investigated under GT-POWER simulation environment. This paper showed analytic result of combustion characteristics and diesel exhaust valve's control with GT-Power 1-D detail model. As a result, it was found that volumetric efficiency and IMEP were decreased as the exhaust valve opening and closing timing is advanced due to its internal EGR effects. Also, it was found that NOx emission were decreased as EVC timing was retarded. These show that the retarding the exhaust valve closing and opening while keeping the duration at constant can be effective for controlling AFR and mixing rate in diffusion combustion of diesel engine.

• Journal of Environmental Science International
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• v.20 no.11
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• pp.1437-1445
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• 2011

The adsorption performance of lead ion was studied using five zeolites (Na-P1, sodalite (SOD), analcime (ANA), nepheline hydrate (JBW), cancrinite (CAN)) synthesized from Jeju scoria. The adsorption performances of lead ion decreased in the order of Na-P1 > SOD > ANA > JBW > CAN. These results showed that the synthetic zeolite with a higher cationic exchange capacity showed a higher adsorption performance. The uptake of lead ion by synthetic zeolites were described by Freundlich model better than Langmuir model. The adsorption kinetics of lead ion by synthetic zeolites fitted the pseudo 2nd order kinetics better than pseudo 1st order kinetics. The effective diffusion coefficients of lead ion by synthetic zeolites were ten times higher than the zeolite A synthesized from coal fly ash.