• Journal of the Korean Institute of Rural Architecture
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• v.19 no.1
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• pp.23-34
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• 2017

The purpose of this paper is to suggest the preliminary data for the improvement of the senior centers' indoor environment and the upcoming progress located in rural areas. In wanju county, 81.8% of seniors were enrolled in senior centers, and used the facility everyday. Also, most of the users tended to use the facilities between 12 a.m. and 6 p.m. The majority of users had lunch at the senior centers. The facilities of most senior centers were in poor condition, and some had their restroom outdoor. Also, most senior centers are exposed to high concentrations of carbon dioxide during winter. During this season, the thermal environment in the restroom was bad. However, the users' level of the facilities' satisfaction was positive. Senior centers have been operating the facilities with difficulties, due to the low financial support from the local autonomous organization. The indoor temperature in most centers, especially, was above $30^{\circ}C$ during summer on account of lack of funding for airconditioning. Therefore, it could be recommended that the local autonomous entity start regular check-ups and repairs for the poor indoor environment and facilities, with more financial support and active supervision of the management.

• Journal of Korean Society of Forest Science
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• v.95 no.2
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• pp.168-173
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• 2006

Stem respiration rate ($R_{stem}$) was examined using an open flow system on black locust (Robinia pseudoacacia L.). $R_{stem}$ exponentially increased with increasing air and stem temperature during measurement period and was most closely correlated with stem temperature. It was more closely correlated with stem temperature observed 0.5-2.0 hrs earlier than with current stem temperature, that is, there was time lag between the increase of stem temperature and the efflux of $CO_2$ from stem. $R_{stem}$ gradually increased from spring to summer, and then decreased during autumn. $R_{stem}$ ranged from 0.13 to $4.44{\mu}mol$ $CO_2m^{-2}s^{-1}$. $Q_{10}$ decreased with increasing stem temperature, and varied along position (or diameter) within trees during the same period, especially during the growing season. On the other hand, time lag was shortened with increasing temperature.

• Journal of Environmental Impact Assessment
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• v.15 no.2
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• pp.157-163
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• 2006

The purpose of this study is to understand imperviousness impact for the characteristics of stormwater runoff and water temperature. The land-use map was used to estimate the watershed imperviousness(percent of impermeable area) and the RMS(Remote Monitoring System) was used to evaluate the stormwater runoff of watershed. This study was investigated for two streams(Jiam and Gongji) in Chunchon City. The detailed results of these studies are as follows; The imperviousness(%) of two watersheds(Jiam and Gongji) estimated by spatial analysis which is main function of GIS were 0.24% and 24.16%. So, Gongji watershed as urban area was about 100 times than jiam watershed as forest area. In case of rainfall of low intensity, stormwater runoff flowrate in higher imperviousness area(Gongji) was more than it in forest area(jiam). Also, The time to peak flowrate(Tp) was short in Gongji stream and the water temperature difference between Gongji and Jiam stream was about $4.4^{\circ}C$ in summer.

• Journal of Korean Society on Water Environment
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• v.22 no.2
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• pp.209-214
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• 2006

The purpose of this study is to improve the stream water quality by the experimental hybrid constructed wetland system. It consisted of the water layer, sand bed planted reeds, irises and roses, gravel bed, yellow-soil media bed and a flow shifter (FS) which can reverse top and bottom flow in the middle of the wetland. The organic compounds and nitrogen removal efficiencies varied with the seasons, namely temperature change. In summer, the mean efficiencies of COD and TN in the outflow from this wetland system were 63.4 and 48.0% and shown the highest, respectively, whereas, the suspended solids and phosphorus removal efficiencies seemed to be less affected by temperature. As a result of inspecting the decreasing trend of pollutants, nitrification-denitrification in the wetland was the major removal mechanism for nitrogen, the nitrogen reduction was especially enhanced by the application of a FS in the wetland, and phosphorus reduction was mainly occurred as a consequence of adsorption of the yellow-soil media.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.1092-1099
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• 2009

Landslide researches are divided to a method of interrelationship for various factors, method of predicting landslide possibility, and method of estimating landslide risk which are occurring landslides in the natural slope. Most of landslides occurred in natural slope are caused by a heavy rainfall in summer season. Weathered soil layer located in upper side of rock mass was occurred. As well as, they are announced to have an influence to geometry, geology, soil characteristics, and precipitation in the natural slope. In order to investigate and interpret the variety of landslides from field investigation to risk analysis, landslide analysis process due to geotechnical and geological opinions are systematically demanded. In this research, the study area is located in Macheon area, Gyeongsangnam-do and performed the landslide investigation. From the results of landslide investigation and analysis, optimized standard model based on natural landslide is proposed to high technical method of landslide investigation and interpretation.

• 한국태양에너지학회:학술대회논문집
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• 2011.11a
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• pp.202-207
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• 2011

This study has measured indoor temperature and relative humidity and evaluated it for one year by selecting Chungnam's rural areas for improving indoor environment of rural housing in the circumstance that the environment of housing is poor due to deterioration of rural housing. As a result of its evaluation, the indoor temperature difference by household appeared to be more than $13^{\circ}C$, and it was measured that the indoor temperature was mostly low. A difference of more than 40% in case of relative humidity occurred, so the difference of the indoor environment by household was clear. In case of the thermal comfort zone, the number of households that are distributed to more than 50% of a thermal comfort criterion in the winter was only 3 households, rather than the summer.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.2
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• pp.83-90
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• 2018

This study was conducted to investigate the living environment of semi-basement housing units in multi-household houses. It analyzed measurements of temperature and humidity obtained from the housing units. For this study, temperature and humidity sensors were installed in 10 semi-basement housing units to measure interior temperature and humidity for 13 months. A survey was conducted to get information about the occurrence of dew condensation and mildew and to investigate residents' satisfaction level with the residential environment. According to the result, all the housing units under study had dew condensation and mildew. The average summer temperature of the 10 housing units was $27.84^{\circ}C$, and average humidity was 64.91%RH, while the average winter temperature was $20.6^{\circ}C$, and the average humidity was 40.12%RH. Depending on the condition of each housing unit, deviation was big. Residents' average level of satisfaction with the living condition was 2.03 which shows a low satisfaction (on a scale of 1-5 with 5 being completely satisfied.).

• Journal of Korean Society for Atmospheric Environment
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• v.31 no.3
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• pp.269-286
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• 2015

24-hr integrated $PM_{2.5}$ measurements were performed between December 2013 and October 2014 at an urban site in Gwangju and the collected samples were analyzed for organic carbon (OC), elemental carbon (EC), ionic species, and elemental species. Objectives of this study were to identify $PM_{2.5}$ pollution episodes, to characterize their chemical components, and to examine their probable origins. Over the course of the study period, average $PM_{2.5}$ concentration was $37.7{\pm}23.6$ $(6.0{\sim}121.5){\mu}g/m^3$. Concentrations of secondary ionic species; $NH_4{^+}$, $NO_3{^-}$, and $SO_4{^{2-}}$ was on average $5.54{\mu}g/m^3$ (0.28~ 20.86), $7.60{\mu}g/m^3$ (0.45~ 33.53), and $9.05{\mu}g/m^3$ (0.50~ 34.98), accounting for 13.7% (4.6~ 22.7), 18.6% (2.9~ 44.8), and 22.9% (4.9~ 55.1) of the $PM_{2.5}$ concentration, respectively. Average OC and EC concentrations were $5.22{\mu}g/m^3$ and $1.54{\mu}g/m^3$, taking possession of 4.6 and 22.2% (as organic mass) of the $PM_{2.5}$, respectively. Frequencies at which 24-hr averaged $PM_{2.5}$ exceeded a 24-hr averaged Korean $PM_{2.5}$ standard of $50{\mu}g/m^3$ (termed as an "episode" in this study) were 30, accounting for 21.3% of total 141 measurements. These pollution episodes were mostly associated with haze phenomenon and weak surface wind speed. It is suggested that secondary formation of aerosol was one important formation mechanism of the episodes. The episodes were associated with enhancements of organic mass, $NO_3{^-}$ and $SO_4{^{2-}}$ in winter, of $NO_3{^-}$ and $SO_4{^{2-}}$ in spring, and of $SO_4{^{2-}}$ in summer. Potential source contribution function results indicate also that $PM_{2.5}$ episodes were likely attributed to local and regional haze pollution transported from northeastern China in winter, to atmospheric processing of local emissions rather than long-range transport of air pollutants in spring, and to the $SO_4{^{2-}}$ driven by photochemistry of $SO_2$ in summer.

• Proceedings of KOSOMES biannual meeting
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• 2006.05a
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• pp.129-135
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• 2006

This study was performed to characterize the seasonal variation of water quality and sediment environment from May, 2004 to February, 2006 in 21 stations of Gwangyang bay. Gawngyang bay is located in the middle of south coast of Korea and semi-dosed with Yeosu peninsula, Gwangyang-city and Namhea-do. Water quality at the west coast of Myo-do were highly deteriorated than other stations. At summer season(July 2005), the concentration of the most analytical items were highly detected than other seasons and the lowest concentration was at the winter season(January 2005, February 2006). Especially, DIP and TP were highly detected around the coast of Yeosu industrial complex. N/P ratio were higher than 16 of Redfield ratio in the spring(May 2005) and winter(February 2006) at the surface layer. While at other seasons and most stations were lower than 16 of Redfield ratio. In the survey of sediment environment, ignition loss(IL), chemical oxygen demand(COD) and acid volatile sulfide(AVS) were in the range of $2.51\sim22.10%,\;2.65\sim48.41mg/g-dry\;and\;0.01\sim8.95mg/g-dry$, respectively. COD in surface sediment was highest at summer season AVS was highest at autumn. In sediment, the corelationship coefficients between COD and IL, COD and AVS were 0.65 and 0.44, respectively.

• Journal of Environmental Science International
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• v.19 no.11
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• pp.1407-1421
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• 2010

This study was carried out to elucidate the relation between water quality and structure of the aquatic ecosystem in the agriculture reservoir Otae-ji from January to December in 2009. The proportion of forest was 46.98%, which means that non-point sources are major contributor of water pollution in this area. The annual mean COD(Chemical Oxygen Demand) in Otae-ji was $3.6mgL^{-1}$, indicating, level II of environmental standards and the trophic state was mesotrophic. Although total phosporus concentration in the reservoir was high in August due to large inflow of nutrients from outside the reservoir during monsoon season, there was no break out of significant algal bloom in the summer. The seasonal succession of phytoplankton showed that the dinophyta dominated in the the spring, chlorophyta in the summer, chrysophyta and chlorophyta in the autumn and chrysophyta in the winter. In case of zooplankton, rotifers dominated in the most seasons, but cladoceran(Bosmina longirostris) dominated in June and copepod(Nauplii) in August. The macrophyte plants showed diverse species compositon consisted of 3 varieties, 24 species, 23 genera, 15 families and 14 orders. The macroinvertebrates also showed various FFG(Functional Feeding Groups) such as GC(Gathering-Collector), P(Predator), SH(Shedder), FC(Filter-Collector) and PP(Plant-Piercer). Ecosystem stability analysis using aquatic insects was classified as Group I, which has high resilience and resistance indices. A total of 14 species of fish was collected but exotic species such as Lepomis macrochirus and Micropterus salmoides were not found in Otae-ji. In conclusion, the preservation of healthy food wed in the reservoir ecosystem is closely related to water quality management as well as effective prevention of algal bloom by helping good material circulation in aquatic ecosystems.