• Korean Journal of Environmental Agriculture
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• v.12 no.1
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• pp.19-25
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• 1993

The water quality at Seomjin River stream was surveyed at 8 sites of main stream and 4 sites of tributaries for 6 months from April to September in 1989. The overall results are summarized as follows: 1. Do concentration of main stream ranged from 7.5 to 9.0 ppm. 2. The average $No_3-N$ content of main stream was increased to 3.86 ppm at June, thereafter it was decreased by dilution with rainwater. 3. The water quality of Seomjin River stream was suitable for the irrigation source with the exception of site 8 where the contents of EC, $Cl^-$ and $SO_4\;^{2-}$ were very high according to the influence of sea water. 4. In the influence of tributaries on changes of the water quality along the Seomjin River, the water quality of main stream was deteriorated with inflow of Osu-cheon and Yo-cheon in the middle stream, but thereafter it was recovered with inflow of Boseong River and Hwangjeon-cheon. 5. The Yo-cheon was rapidly polluted by the sewage of Namweon city, that is, contents of COD and $NO_3-N$ were incresed from 0.97 to 7.10 ppm and from 1.86 to 3.11 ppm respectively.

• Ecology and Resilient Infrastructure
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• v.2 no.4
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• pp.305-310
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• 2015

In 2014, the city of Seoul revised the ordinance regarding water-cycle restoration in the Seoul Metropolitan areas by incorporating the 'Low Impact Development (LID)' policy. The new ordinance plan will utilize 630 mm or almost 45 to 50% of annual rainfall until 2050 by means of providing a rainwater management system consisting of infiltration, retention and vegetation. The LID is believed to be the key to achieving the target requirements, specifically in development projects. This research was performed to evaluate the stormwater runoff and pollutant reduction performance of three different LID facilities (water circulation facilities) including an infiltration inlet, bioretention swale, and permeable pavement constructed in Seoul City. Results show that among the water circulation facilities, the permeable pavement achieved the highest runoff reduction as it was able to entirely capture and infiltrate the runoff to the ground. However, in order to attain a long-term performance it is necessary to manage the accumulated sediment and trapped pollutants in the landscape areas through other water circulation techniques such as through soil erosion control. In terms of pollutant reduction capability, the infiltration inlet performed well since it was applied in highly polluted areas. The bioretention facility integrating the physico-chemical and biological mechanisms of soil, microorganisms and plants were able to also achieve a high runoff and pollutant reduction. The water circulation facilities provided not only benefits for water circulation but also various other benefits such as pollutant reduction, ecological restoration, and aesthetic functions.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.1
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• pp.104-110
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• 2006

Growth in population and urbanization has progressively increased the loadings of pollutants from non-point sources as well as point sources. Accordingly, release of contaminants from non-point sources, released with surface runoff of rainwater, is influenced by atmospheric phenomena, geology, and topography. This makes the control of non-point source difficult. Therefore, this study intends to reveal the characteristics of runoff and particle size distribution to observe the fundamental characteristics of runoff. Experiments were carried out at inner road of research center. Average concentration of runoff ranged from 26.8 to 126.4 mg/L for SS and $COD_{Cr}\;15.3{\sim}117.7mg/L,\;TN\;0.07{\sim}5.16mg/L,\;TP\;0.06{\sim}0.49mg/L$ and heavy metals $0.00{\sim}0.29mg/L$. First flush, indicated wash off of pollutant at first rain, was observed for all types of pollutants. Most pollutants revealed a very close correlation with SS ($R^2=0.93{\sim}0.99$). After analyzing characteristics of particle, particle was finer than that from previously examined data.

• Journal of Conservation Science
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• v.18 s.18
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• pp.63-74
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• 2006

All rock materials of the three storied stone pagoda in Seoakri were composed of light gray alkali granite with medium grained and developed with small mialolitic cavities. This stone pagoda is preserving almost archetype except the head part because there was repair work already. But, foundation, basement and roof rocks are serious state by microbial invasion such as lichens. Because there are tree and grass that cause direct effect to stone pagoda surrounding. Therefore, conservation treatment executed the primary dry cleaning and secondary wet cleaning treatment. Stone surface is partly not removed well such as lichens which part removed using cleansing device that use high temperature steam. Some treated part concrete and epoxy resin remove and retreatment with mixing talc and alkali granite powder to epoxy resin. Did color matching at mixing process of epoxy resin and fillers to properties with set the feel of a material. Also, drainage ditched to minimize inflow of rainwater fall from slope that is on the east of stone pagoda, tree and grass in stone pagoda surrounding wished to do remove and control occurrence of lichens hereafter minimizing moisture conteats.

• Journal of agricultural medicine and community health
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• v.21 no.2
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• pp.231-241
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• 1996

The estimation of medical care status and the planning of health service program should be done according to each community resident's socio-medical background and public health service. In this point, it is most necessary to be set the exact and new socio-economic statistics data in Nepal, one of the worst countries in national health status. We surveyed 668 house, 3,425 residents in Dolka area, Nepal from January 25th to February 1st, 1995. 1. In personal characteristics, the ratio of men and women was similar, the person who were below 19 years old were 28.1% and the single were 52.4%. The illeterate person were 50.3% and the lower group in economic status which had been estimated by interviewers were 46.9%. 2. In sanitational characteristics, the person who used stream water or rainwater to drink were 42.2% and the person who always boiled water to drink were only 8.3%. The person who had not toilet in their house were 67.3% and the lower group in sanitational status which had been estimated by interviewers were 61.8%. 3. The prevalence rate of illness during the last one month were 8.6% and the chronic were 26.1% and the acute were 72.5%. The distribution of sickness symptom were headache, fever and joint pain in order and the person who took no medical treatment among the sick were 37.0%. The patterns of medical utilization were public health center, hospital and pharmacy in order. 4. Illness prevalence was significantly related to sex, age, merital status and educational experience. The residents who were women, 40 years old or more, married and had not educational experience were apt to take illness. 5. Medical utilization was significantly related to educational experience, job, distance from home to medical facilities and economic status. The person who had educational experience, were officer workers or merchants, lived near by medical facilities and had higher economic status took medical treatment very well.

• Journal of the Korea Computer Graphics Society
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• v.25 no.5
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• pp.1-9
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• 2019

In this paper, we propose a video enhancement method using generative adversarial networks to remove raindrops and restore the background information on the removed region in the coastal wave video imagery distorted by raindrops during rainfall. Two experimental models are implemented: Pix2Pix network widely used for image-to-image translation and Attentive GAN, which is currently performing well for raindrop removal on a single images. The models are trained with a public dataset of paired natural images with and without raindrops and the trained models are evaluated their performance of raindrop removal and background information recovery of rainwater distortion of coastal wave video imagery. In order to improve the performance, we have acquired paired video dataset with and without raindrops at the real coast and conducted transfer learning to the pre-trained models with those new dataset. The performance of fine-tuned models is improved by comparing the results from pre-trained models. The performance is evaluated using the peak signal-to-noise ratio and structural similarity index and the fine-tuned Pix2Pix network by transfer learning shows the best performance to reconstruct distorted coastal wave video imagery by raindrops.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.453-460
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• 2004

To prevent penetration of rainwater into the landfill site is the main purpose of the final cover in landfill sites. Conventional designs of landfill covers uses geotextiles such as geomembrane and GCL, and clay liners to lower the permeability of final covers of landfill sites. However, differential settlement and the variation of temperature in landfill sites cause the development of cracks or structural damage inside the final cover and it is also difficult to obtain clay - the main material of the compacted clay liner in Korea. Thus the former final cover system that suggests geomembrane and GCL or compacted clay liner has several limitations. Therefore, an alternative method is necessary and one of them is the application of SRSL(self-Recovering Sustainable Liner) material. SRSL is two different layers consist of individual materials that react with each other and form precipitates, and with this process lowers the permeability of the landfill final cover. SRSL generally is made up of two layers, so that when a internal crack occurs the reactants of the two layers migrate towards the crack and heal it by forming another liner. In this study the applicability of SRSL material for landfill final cover was examined by performing; (1) jar test to verify the formation of precipitate in the mixture of each reactants, (2) falling head test considering the field stress in order to confirm the decrease of permeability or prove that the hydraulic condctivity is lower than the regulations, (3) compression tests to judge weather if the strength satisfies the restricts for landfills, (4) freeze/thaw test to check the applicability of SRSL for domestic climate. In addition, the application of waste materials in the environmental and economical aspect was inspected, and finally the possibility of secondary contamination due to the waste materials was examined by performing elution tests.

• Journal of Environmental Science International
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• v.27 no.5
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• pp.291-297
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• 2018

Vertical farming systems offer many advantages in urban spaces. They have also been proposed as an engineering solution to increase the productivity per unit area of cultivated land by extending crop production in the vertical dimension. However, soil water retention is a major constraint affecting the plant environment. This study analyzed the effects of growth environment of Tropaeolum majus and Fragaria spp., on the vertical farming system, by using four different types of cover material types including sphagnum moss (Control), a shading net (S.N.), multi-layered fabric (M.L.F.), and non-woven fabric (N.W.F.). The volumetric soil moisture contents and plant characteristics were investigated from May to September 2014. Plant materials were individually cultivated in hanging baskets measuring $30{\times}17{\times}17cm$, filled with a mixture of soil and perlite, and placed at 1.5m height. Each treatment was performed in quadruplicate and consisted of five plants, amounting to a total of 20 plants. The analysis indicated that different covers were associated with multiple functions and soil water retention improvements may have a positive impact on the vertical farming system. The difference in soil water retention increased in the following order: M.L.F. > Control > N.W.F. > S.N.. Furthermore, the differences in plant height and survival rate increased in the following order: M.L.F. > Control > N.W.F. > S.N. Therefore, M.L.F yielded satisfactory good response for the vertical farming system of cover materials. Our results clearly demonstrate that vertical spaces represent an attractive alternative to urban farming and suggest that further increases in yield may be achieved via different cover materials in vertical farming using hanging baskets.

• Economic and Environmental Geology
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• v.30 no.1
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• pp.25-33
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• 1997

The purpose of this study is to examine the feasibility of using stable isotopes as a hydrologic tracer, and to elucidate the groundwater circulation system and the source of S component dissolved in thermal water of the Chonju Jukrim thermal spring district based on the O, H and S isotopic variabilities of environmental materials including bedrock, rainwater, surface water, shallow subsurface water and thermal spring water. The ${\delta}^{18}O$ and ${\delta}D$ of subsurface waters and surface water show highly restricted range and plotted on the same meteoric water line as a ${\delta}D=8{\delta}^{18}O+19$ line, and derivate from the mean annual isotopic composition of the rain water but are analogous to those of rain waters precipitated during winter season, indicating that ground waters are originated from the meteoric water and are strongly affected by the seasonal variation of air mass. Thermal spring waters are more depleted in ${\delta}^{18}O$ and ${\delta}D$ than those of shallow ground water and surface water. It can be explained by the difference of recharge area. The hydrochemical properties of subsurface waters and surface water devide into two groups: $Ca(HCO_3)_2$ type including shallow subsurface water and surface water, and $Na(HCO_3)$ type of thermal spring waters. The ${\delta}^{34}S$ values of thermal spring water show very high positive and quitely distinct from those of shallow subsurface water and surface water that are similar to those of bed rocks, indicating that sulfate dissolved in thermal spring water has not only a terrigenic origin, but also originates partially from the foreign source containing very heavy ${\delta}^{34}S$ component such as an ancient sea water. However, the presence of $H_2S$ can not be ignore the affact of the isotopic fractionation to explaine the heavy ${\delta}^{34}S$ of thermal spring water. Overall, the Oxygen and Hydrogen stable isotopes can identify the source and the circulation system of the natural waters and the S-isotopes can provide a crucial clue on tracing the dissolved material transports in the circulation system of the natural water.

• Korean Journal of Ecology and Environment
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• v.35 no.1 s.97
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• pp.36-44
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• 2002

The spatial and temporal trends of water qualities in Lake Soyang was statistically analyzed in this study. The water qualities include nutrients, ionic contents and chlorophyll-a (Chl-a) measured during 1993${\sim}$2000. The rainfall intensity and runoff from the catchment appeared to play an important role in water quality trends in the lake. According to seasonal Mann-Kendall test, conductivity, TP, and Ctl-a did not show any trends of increase or decrease over the 8 year period, while TN declined slightly. It was found that the variation of TP was a function of interannual inflow and rainfall. In the analyses of spatial trend, conductivity, based on the mean by site, showed a downlake decline over the eight year period. Minimum conductivity was found in the headwaters during summer monsoon of July to August and near the dam during October. This result indicates a time-lag phenomenon that the headwater is diluted by rainwater immediately after summer monsoon rain and then the lake water near the dam is completely diluted in October. During summer period, TP and TN had an inverse relation with conductivity values. Concentrations of TP peaked during July to September in the headwaters and during September in the downlake. Also, TN increase during the summer and was more than 1.5 mg/L regardless of season and location, indicating a consistent eutrophic state. Values of Chl-a varied depending on location and season, but peaked in the midlake rather than in the headwaters during the monsoon. Regression analyses of log-transformed seasonal Chl-a against TP showed that value of $R^2$ was below 0.003 in the premonsoon and monsoon seasons but was 0.82 during the postmonsoon, indicating a greater algal response to the phosphorus during the postmonsoon. In contrast, TN had no any relations with Chl-a during all seasons.