• KSBB Journal
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• v.27 no.4
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• pp.227-231
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• 2012

Whole plants of Zostera asiatica were extracted twice with acetone/methylene chloride (A+M) and methanol (MeOH) in turn. The combined crude extracts were evaporated in vacuo and then the residue was partitioned between water and methylene chloride. The aqueous layer was fractionated into $H_2O$ and n-butanol and then the organic layer was also fractionated into 85% aq. MeOH and n-hexane, successively. The crude extracts and their solvent fractions were evaluated for their inhibitory effect on growth of human cancer cells AGS, HT-29, MCF-7, and HT-1080 cells by MTT reduction assay. Among samples tested, 85% aq. MeOH and n-hexane fractions showed strong cytotoxic effect against AGS, HT-29, and MCF-7 cells. On the other hand, for HT-1080 cell, 85% aq. MeOH fraction exhibited the strongest cytotoxic effect.

• Journal of Environmental Science International
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• v.20 no.9
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• pp.1105-1114
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• 2011

In this study, thermal environment improvements throughout public design improvement project on the urban street space were compared and evaluated. Thermo-Render 3.0, 3D-CAD based thermal environment simulation program, had been used for thermal environment improvement evaluations. Followings are the results. First, clayey blocks which have low heat transfer rate and cool island effect by trees and roof gardens brought cooling effects for buildings and surface of streets. Seconds, MRT values showed low levels because of low radiant mulching materials. Thirds, roof gardens contributed to reduce heat island effect since HIP levels were affected by decreasing heat storage effect of buildings from roof gardens. As a result, reducing heat storage effect throughout selecting and arranging proper materials which would not increase heat island potentials should be performed to improve heat island effects.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.54 no.7
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• pp.366-374
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• 2005

The purpose of this study is to find out main factors affecting public enterprise's environment , which improves the performance of public enterprise. In detail, under the premises of keeping publicity in Korea Electricity Industry, the main target of this study is to seek after factors enhancing entrepreneurship and deals with publicity which is related with entrepreneurship. Questionnaires are distributed to the employee of public enterprise, public servants, and civil corps. A total of 553 copies are collected. The main contents of questionnaires are related with the effect of publicity and entrepreneurship by government control, competitive environment and shareholding structure in Korea Electricity Power Corporation(KEPCO). The results of this survey are as follows : First government control is negatively related to the entrepreneurship while it is positively related to the Publicity. Second, this suey shows that competitive environment has a Positive influence on promoting both publicity and entrepreneurship. Third this survey in connection with shareholding structure indicates that present structure in KEPCO has a positive effect on publicity but negative effect on entrepreneurship. According to this empirical results, it is verified that the main issues on the performance of KEPCO ue related with the level of government control and competitive environment in its industry.

• Journal of Environmental Science International
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• v.17 no.6
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• pp.623-631
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• 2008

Many recent studies have concentrated upon the radiative effects of atmospheric aerosols. Though their scattering and absorption of radiation, aerosols can also induce some other important environment effects. In this study, new radiation code and aerosol data within Atmosphere General Circulation Model (AGCM) is used to assess the aerosol radiative forcing and to analyze relative climate effects. The new Kangnung National University AGCM Stratospheric-15 (KNU AGCM ST15) was integrated by using two sets of radiative effect of aerosols: CTRL as not a radiative effect of aerosols and AERO as a radiative effect of aerosols. Two cases show the difference of net shortwave radiation budget at top-of-atmosphere (TOA) is found to be about $-3.4Wm^{-2}$, at the surface (SFC) is about $-5.6Wm^{-2}$. Consequently the mean atmospheric absorption due to aerosol layer in global is about $2.2Wm^{-2}$. This result confirms the existence of a negative forcing due to the direct effect of aerosols at the surface and TOA in global annual mean. In addition, it is found that cooling over at the surface air temperature due to radiative effect of aerosols is about $0.17^{\circ}C$. It is estimated that radiative forcing of the net upward longwave radiation taken as the indirect effect of aerosol is much smaller than that of the direct effect as there is about $0.2Wm^{-2}$ of positive forcing both at TOA and at SFC. From this study, It made an accurate estimation of considering effect of aerosols that is negative effect. This may slow the rate of projected global warming during the $21^{st}$ century.

• Journal of Korean Society on Water Environment
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• v.31 no.2
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• pp.87-93
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• 2015

In this study, the inhibitory effect of toxic metals was investigated on the activated sludge of the municipal sewage treatment plant. The allowable concentration of toxic metals was also estimated for the stable operation of the biological treatment process. The single and mixture toxicity of $Cu^{2+}$, $Al^{3+}$ and $Zn^{2+}$ were evaluated for the activated sludge microorganisms. As a result, nitrifying microorganisms were more susceptible than heterotrophic microorganisms. $IC_{10}$ (Inhibition Concentration of 10%) of $Cu^{2+}$, $Al^{3+}$ and $Zn^{2+}$ for the nitrifying microorganisms was 3 mg/L, 7 mg/L and 25 mg/L, respectively. The mixture toxicity showed three times more sensitive than the single toxicity. The concentrations of $Cu^{2+}$, $Al^{3+}$ and $Zn^{2+}$ to minimize the inhibitory effect on organic matter removal and nitrification in batch experiments were found to be 1.3 mg/L, 2.5 mg/L and 6.3 mg/L.

• Journal of Korea Multimedia Society
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• v.6 no.7
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• pp.1286-1301
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• 2003

This paper introduces segmentation based environment modeling method and integration method using multiple environment map for constructing the realtime image-based panoramic navigation system. The segmentation-based environment modeling method is easy to implement on the environment map and can be used for environment modeling by extracting the depth value by the segmentation of the environment map. However, an environment model that is constructed using a single environment map has the problem of a blurring effect caused by the fixed resolution, and the stretching effect of the 3D model caused when information that does not exist on the environment map occurs due to the occlusion. In this paper, we suggest environment models integration method using multiple environment map to resolve the above problem. This method can express parallax effect and expand the environment model to express wide range of environment. The segmentation-based environment modeling method using multiple environment map can build a detail model with optimal resolution.

• The Journal of Information Systems
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• v.15 no.4
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• pp.23-53
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• 2006

The main purpose of this paper is to setup a integrated model and verify the integrated model for a customer loyalty in the internet shopping environments. The results of a structural equation model (SEM) using AMOS and LISREL include: First, hypothesis that Internet environment characteristics in outside factors has a positive effect on satisfaction, trust and commitment is partially supported. However, mutual communication to satisfaction, community to commitment and open-ubiquity to trust did not reveal a positive effect. Second, hypothesis that Internet showing mall environment has a positive effect on satisfaction is partially supported. However, transaction to commitment and transaction to trust did not reveal a positive effect. Third, hypothesis that relational benefits has a positive effect on both satisfaction and commitment is partially supported. However, confident honest to commitment and economic honest to trust did not reveal a positive effect. Forth, satisfaction trust and commitment have a strong effect upon loyalty. Fifth, satisfaction has a positive effect on trust and commitment. However, trust did not show a positive effect on commitment. Outside factors(Internet environment characteristics, showing mall characteristics, and relational benefit) partially revealed a positive effect on satisfaction trust, and commitment. Mediating variables such as satisfaction, trust, and commitment again have positive effect on loyalty. But, the relationship for trust to commitment did not reveal the significant effect in this study while other studies revealed significant effect.

• Macromolecular Research
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• v.12 no.5
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• pp.484-489
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• 2004

We have prepared a phenothiazine-based nonlinear optical (NLO) chromophore that displays a fairly high microscopic nonlinearity through intramolecular charge transfer. The phenothiazine unit plays important roles of contributing its high electron donating ability and connecting the resonance pathway through a conjugative effect in the cyclized ring adjacent to the aromatic ring. Theoretical calculations and an absorption spectroscopic study provided useful information concerning the microscopic nonlinearity of the chromophores. We investigated the electro-optic (EO) properties of the guest-host systems in amorphous polycarbonate containing the synthesized chromophores at different concentrations under different poling temperatures. A real-time pole and probe method provided a much greater amount of information regarding how the EO properties can arise and how they can be optimized.

• Journal of the Korea Safety Management & Science
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• v.18 no.4
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• pp.73-80
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• 2016

This study highlights the main effect of job demand, work shift, work environment and stressors on the railway traffic controller's health, and the moderating effect of work0life balance. The result of empirical analysis based on questionnaires received from 328 traffic controllers working at 10 railway operating companies indicates that job demand, work shift, work environment and stressors have significant effect on their health, among which stressors is a major factor. In the respect of moderating effect, WLB showed no significance except for job demand. This result implies that controller's health can not be enhanced through their individual family or leisure life. Therefore, effective countermeasures and policy to mitigate their health problems and heal their symptoms are urgent.

• Journal of Korean Society on Water Environment
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• v.27 no.3
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• pp.357-363
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• 2011

In spite of numerous advantages in railroads such as mass transportation, high reliability, and environmental soundness etc., the value of railroad construction is relatively underestimated compared to road. This is because the current method of evaluation focuses mainly on economic effect. In this study, considering recent research results, the environmental value of railroad construction was assessed by calculating the effect of reduction of emissions and water contamination. With these two benefits, the environmental effect produced by railroads and road construction was calculated and compared to each other using EMME/3. As a result, the senario 4 which considers 'Hot/Cold start' condition and water contamination had highest benefits. Furthermore, the environmental effect produced by railroad is 55~101% higher than road construction. If the suggested method is used in the current appraisal system, the environment-friendly mode like railway would be highly valued, much more than before.