• Korean Journal of Plant Resources
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• v.22 no.5
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• pp.412-424
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• 2009

The flora and vegetation of Chuncheon area were investigated from March, 2006 to September, 2008. Vascular plants of investigated regions were composed of 118 families, 496 genera, 894 species, 2 subspecies, 132 varieties, and 38 forms, totally 1,066 taxa, and the Pteridophyta index (Pte-Q) was 1.17. Forty two taxa including endemic genus Hanabusaya and Echinosophora among the 1,066 taxa were Korean endemic. Thirty three rare and endangered plants and 119 specially designated plants by Ministry of Environment were also investigated. The naturalized plants were 71 taxa, and percent of naturalized plant species were 6.66%. The vegetation of Chuncheon area were classified into five communities such as Quercus mongolica community, Pinus densiflora-Quercus mongolica community, Quercus mongolica-Acer mono community, Quercus mongolica-Quercus variabilis community and Quercus mongolica-Betula davurica community.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.1233-1237
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• 2010

강변여과는 지표수와 지하수가 각기 갖는 장점과 제약점을 상호 보완하여 수질이 양호한 상수원수를 대량 확보하기 위한 실제적 대안이다. 자연적인 여과작용에 의해 수질이 개선되는 효과가 있어 경제적이고 안정적으로 확보할 수 있지만, 장기간 취수는 지하수위의 저하를 가져 올 수 있으므로 유역의 수문분석을 통한 기저유출량 산정에 관한 연구가 필요하다. 대상지역으로는 현재 강변여과를 개발중인 창원시 대산정수장 취수장 지역이며, 대상지역의 기저유출량을 산정하기 위해 대상지역 상류에 위치한 낙동강 본포교의 낙동강 유량을 기초로 기저유출량을 산정하여 지하수 함양율을 평가하였다. 수문곡선 분리는 여러 방법 중 다른 방법보다 상대적으로 간편하고 실무에서 많이 사용되는 방법인 수평직선분리법을 사용하여 적정 취수 가능량을 산정하기 위한 최소 기저유출량을 산정하고자 한다. 이에 따라, 보유 자료 중 연 평균 최저 유출량을 보인 2008년 가을 갈수기의 시작(2008년 10월)부터 2009년 가을 갈수기의 시작(2009년 10월)까지의 자료를 분석했다. 본포교 유량 자료는 8일부터 10일 간격으로 측정되고 있기 때문에 결측치는 최인접 두 지점 사이의 선형보간법으로 보완했다. 다소 많은 양의 결측치에 대한 보정과 해당 유역의 연간 유출 특성을 파악하기 위해서 이동평균(moving average)을 적용했으며, 적용 결과 관측 주기에 해당하는 10일 이동평균 유출수문곡선이 가장 적합한 것으로 나타났다. 10일 이동평균에 의한 유출수문곡선에 의하면 상승부의 기점은 2009년 6월 12일로 나타났으며 유출량은 47.87cms로 나타났다. 따라서 총 기저유출량은 상승부 기점의 유출량으로 111일 동안 발생하는 것을 알 수 있었으며 그 총량은 약 45,900만$m^3$으로 나타났다. 본 연구에서의 결과 본포교를 유역출구로 하는 이 유역에는 임의 유출이 생기는 호우사상 시, 기저유출량은 총 유출량의 6.38%를 최소한 기대할 수 있음을 알 수 있다.

• Korean Journal of Plant Resources
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• v.25 no.4
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• pp.416-432
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• 2012

This study was carried out to investigate the distribution and characteristics of plant resources in Mt. Heungjeong (Pyeongchang-gun, Gangwon-do) from April, 2009 to May, 2011. The vascular plants based on voucher specimens were summarized as 403 taxa, including 78 families, 238 genera, 343 species, 3 subspecies, 47 varieties, and 10 forms. Among the investigated 403 taxa, 8 Korean endemic, 1 endangered, and 16 rare plants were included. 71 species of specially designated plant by the Ministry of Environment were also investigated. The naturalized plant were 20 taxa, and the percent of naturalized plant species was estimated as 5.0%. The usefulness of the plants of the 403 taxa listed consists of 175 taxa (43.4%) of edible plants, 126 taxa (31.3%) of medicinal plants, 65 taxa (16.1%) of pasture plants, 52 taxa (12.9%) of ornamental plants, 12 taxa (3.0%) of timber and fiber plants, 3 taxa (0.7%) of industrial plants.

• Membrane Journal
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• v.4 no.4
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• pp.197-204
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• 1994

In this study, permeation characteristics of pure $CH_4,\;CO_2$ and $CH_4/CO_2$ gas mixture were examined by permeation experiments through hollow fiber membrane module and experimental results were compared with simulation results. Permeation rate of pure gas increased with increaseing temperature in Arrhenius type. Activation energy was 6.61 kJ/mol for $CO_2$ and 25.26 kJ/mol for $CH_4$. In the permeation experiment of gas mixture, permeate flow rate and $CO_2$ concentration in permeate decreased and $CH_4$ concentration in reject increased with the increase of cut. Separation factor was in the range of 20~40 at 5~20 atm and 20% cut and it increased with pressure and against temperature Experimental values corresponded to numerical values with the deviation of 8% in permeate flow rate and $CO_2$ concentration in permeate and 15% in $CO_2$ concentration in reject.

• Resources Recycling
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• v.25 no.5
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• pp.57-63
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• 2016

This study were carried out sulfation roasting and selective leaching test for the effective recovery of copper component in concentrate obtained by froth floatation of Autrallian low grade copper ore. The optimum conditions of sulfation roasting were temp. $450^{\circ}C$, $Na_2SO_4$ 2 mole ratio and time 1.5 h, and then selective leaching were room temperature and $H_2O$ or 1M $H_2SO_4$ solutions. Leaching efficiency of optimum sulfation product were 90 wt.% of copper, 20 wt.% of iron and 15wt.% of nickel elements. In this results, it was possible to selective decomposition leaching of the copper component under optimum conditions in this research.

• Resources Recycling
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• v.13 no.4
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• pp.39-45
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• 2004

Solvent extraction experiments of Nd from chloride solution were studied with PC88A. Solvent extraction reaction of Nd with PC88A and the equilibrium constant were evaluated from the extraction experimental data and extraction conditions. Nd$aq^{3+}$ + 1.5 $H_2$$A_2$,org = $NdA_3$,org + 3H/sun $aq^{+}$ , K=0.25 The predicted distribution coefficients of Nd agreed well with the experimental results. The effect of saponification of PC88A on the extraction of Nd and on the change of equilibrium pH was investigated. Saponified PC88A present as a monomer in the organic reaction and enhanced the distribution coefficient of Nd. The initial extraction conditions had a great effect on the equilibrium pH.

• Resources Recycling
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• v.13 no.4
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• pp.11-16
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• 2004

In this study, treatment conditions for monazite concentrate in Hong-Cheon area deposit were studied with NaOH fritting decomposition and HCl leaching experiments. At condition of NaOH fritting decomposition, it was appropriate to adopt particle size of -200 mesh monazite, reaction temperature of about $460^{\circ}C$ and NaOH/TREO mole ratio of 6. In case of HCl leaching for decomposed product, it was appropriate to use hydrochloric acid of above 8N with leaching temperature of above $80^{\circ}C$, leaching time of 2 hrs and pulp density of about 10%. A rate of decomposition and leaching for monazite was above 90% under optimum conditions. Sodium phosphate compound was effectively recovered from NaOH decomposed solution, and mixed rare earth chloride solution was prepared with HCl leaching of decomposed product.

• Resources Recycling
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• v.21 no.2
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• pp.17-33
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• 2012

In order to review the recent technological progress and issues on the urban mine resources recycling in Japan and Korea, recycling process of the ELV(End of Life Vehicles) and E-waste(WEEE) were studied. Although technological level for processing of the ELV and E-waste is almost similar in both countries, the treatment of hazadous materials of ELV such as freon, air bag and ASR is unsufficient in Korea. In the E-waste recycling, the technological level is deeply different according to the enterprise size in Korea. Finally, the big R&D project on recycling of urban mine resources sponsored by government in both countries were discussed.

• Environmental and Resource Economics Review
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• v.30 no.1
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• pp.27-48
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• 2021

We extend and modify the canonical epidemiology model of Eichenbaum, Rebelo and Trabandt (2020) to investigate the general equilibrium effects of COVID-19 spread in the Korean economy when vaccine, treatment and social distancing are available. Particularly, we develop a SIR-macro model which considers possibility of moral inattention of the overconfident agents through which people is more likely to be infected. Our model implies that people's decision to cut back on consumption and work reduces the severity of the epidemic and thus exacerbate the size of the economic recession caused by the epidemic. Another finding is that the average 13 weeks to develop the vaccine and treatment will lead to 2% drop of consumption.

• The Journal of the Korea Contents Association
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• v.22 no.4
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• pp.609-619
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• 2022

This study was performed to research the influencing factor of COVID-19 preventive behavior focused on people in their 20s and 30s who recently have a high infection rate of COVID-19. The online survey was conducted through structural questionnaire aimed at 210 people in their 20s and 30s of metropolitan area from July 10th to 19th in 2021. The results are as follows. First, as a result of analyzing the relation between health belief and COVID-19 preventive behavior, as perceived seriousness, perceived vulnerability, perceived disability and perceived benefit, COVID-19 preventive behavior is well conducted. Second, as perceived benefit of health belief get higher, the subjective norm is well observed. Third, as subjective norm and perceived behavioral control become higher, COVID-19 preventive behavior is well conducted. Fourth, the subjective norm and perceived behavioral control have a mediating effect in the relation between subjective norm.