• Journal of Korean Society of Forest Science
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• v.104 no.2
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• pp.261-266
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• 2015

This study was conducted to examine the effect of tree density of Pinus koraiensis forest on the thermal comfort and the physiological response of human body in summer season. As the indicators of thermal comfort were used the predicted mean vote (PMV) and predicted percentage of dissatisfied (PPD), while the heart rate variability was used for the physiological indicator of subjects. The subjects were 15 physically healthy men and women in their 20s ($23.7{\pm}1.7$ years old). The subjects sat in each site to measure HRV for 5 minutes and the thermal comfort of each site was measured. As a results, it was proven by PMV and PPD that the Pinus koraiensis forest with 120% tree density was thermally more comfortable than the Pinus koraiensis forest with 80% tree density. In case of the subjects' physiological response, the Pinus koraiensis forest with 120% tree density showed significantly higher HF of HRV than the Pinus koraiensis forest with 80% tree density and significantly lower LF/HF. Therefore, the findings of this study scientifically proved that the Pinus koraiensis forest with 120% tree density is thermally more comfortable and physiologically more relaxing than the Pinus koraiensis forest with 80% tree density.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.6
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• pp.627-639
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• 2014

In respect of the nutrients cycling in coastal environment, regeneration in bottom layer is one of major source of nutrients. We analyzed the bottom water quality at the 14 stations during 9 years from 2004 to 2012 to investigate the characteristics of nutrients at bottom layer in Jinhae Bay. Concentrations of DIN, DIP and DSi showed the large seasonal variation and were higher in summer. Especially, average concentrations of these nutrients were two times higher in hypoxic season than in normoxic season. In summer, high concentrations of DIN, DIP and DSi caused by regeneration were common feature, but spatial distribution of DSi differ from that of DIN and DIP. DIN and DIP were higher in Masan Bay, while DSi was higher in Masan Bay as well as in center of Jinhae Bay. In comparison with DIN and DIP, DSi was significantly affected by nutrients regeneration at bottom layer in whole season. According to time series analysis, DIN concentration was decreased from approximately $14{\mu}M$ to $6{\mu}M$. This result induce that Si:N ratio at bottom layer in Jinhae Bay changed from approximately 1 to 3.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.977-982
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• 2011

This study was conducted to redetermine the rainfall erosion factor (R factor) in USLE for the estimation of soil loss at Korea. The redetermined R factor may be applied more precisely to interpret the changes of regional/yearly/seasonal patterns, including the amount of rainfall and the kinetic energy of rainfall, in Korea. This study calculated the R factors based on 60-minute precipitation data from 60 sites covering the whole country for 30 years from 1981 to 2010. As a result, the annual mean rainfall was $4,147MJ\;mm\;ha^{-1}\;yr^{-1}\;hr^{-1}$ in Korea. Coastal regions of Jeonnam and Gyeongnam, northwest regions of Gyeonggi, and Seoul had the greater values of R factor compared to other regions. The annual mean R factors for every decade were 3,988, 4,085, and $4,370MJ\;mm\;ha^{-1}\;yr^{-1}\;hr^{-1}$ in 1981~1990, 1991~2000, and 2001~2010, respectively. Generally, the R factors had an increasing tendency over and over pest decades. The ratios of summer R factor to total annual mean R factor were 69.8% (1981~1990), 73.7% (1991~2000), and 74.2% (2001~2010). We found that the absolute values and the relative ratios of summer rainfall are gradually increased.

• Journal of Environmental Health Sciences
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• v.47 no.2
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• pp.182-191
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• 2021

Objective: This study was performed to detect indicator bacteria in drinking spring water samples in Gwangju City and to identify their genus using the VITEK-II system. Methods: The subjects were ten drinking spring water sites in Gwangju. Samples of spring water were taken every month from September 2019 to August 2020. We analyzed for the indicator bacteria Yersinia and microorganisms isolated from the spring water. Result: According to the research results on indicator bacteria, general bacteria in st1-st7 with sterilization facilities in the spring and summer were investigated in the range of 0-2 CFU/mL and 0-12 CFU/mL. In st9, where a sterilization facility was not installed, the most general bacteria were detected (160 CFU/mL). Total coliform and fecal coliform showed unsatisfied rates of 16.7 and 11.1% in spring and 14.7 and 11.8% in summer, respectively. The unsatisfied rates of total coliform for the designated and non-designated spring water facilities were 3.8 and 47.1%, respectively, and for the fecal coliform group they were 2.5 and 35.3%. The difference was confirmed according to the presence of a sterilization facility. Yersinia spp. was not detected in all drinking spring water. Forty-one strains in 25 species were isolated from ten sites. The results classified as major dominant species are Pseudomonas spp. 14.6%, Pantoea spp. 9.8%, Serratia spp. 9.8%, Acinetobacter spp. 9.8%, Citrobacter spp. 7.3%, Bordetella spp. 7.3%, Delftia spp. 4.9%, and Enterobacter spp. 4.9%. Conclusions: Based on the result that various species derived from fecal pollution and artificial pollutants were detected in the non-specified public spring water facilities that many people use, the facilities need institutional complements such as continuous management or complete shutdowns.

• Journal of Environmental Science International
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• v.28 no.3
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• pp.303-320
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• 2019

Water quality is characterized by various complex factors. Therefore, a systematic understanding of water quality trends is required to carry out a proper evaluation. In this study, we analyzed the spatio-temporal water quality characteristics of the Nakdong River using five-year data from 2012 to 2016. Data was collected on the pH, DO, BOD, COD, SS, TN, TP, TOC, WT, EC, $NH_3-N$, $NO_3-N$, $PO_4-P$, Chl-a, rainfall, and total and fecal coliforms. A total of 38 water quality measurement stations, from Andong1 to Gupo, were considered. Statistical analyses including trend, cluster, and factor analyses were conducted to identify the dominant water quality components affecting the Nakdong River. The Nakdong River was spatially classified into three groups for up-stream (Andong1 to Sangju1), mid/up-stream (Donam to Dalseong), and mid/down-stream (Hwawonnaru to Gupo) data collection, and temporally into two groups for summer/fall (7~10), and the rest of the season (11~6) data. The water quality of the entire Nakdong River showed trends similar to the mid/down-stream section, which indicates the importance of water quality management in this section. Suspended solids, phosphorus, and coliform groups were established as important factors to be considered in the summer/fall season across the river, especially in the mid/down-stream section. Nitrogen and organic matter were identified as important factors to be considered in the rest of the season, especially in the mid/up-stream section. This study could help determine the water quality components that should be intensively monitored in the Nakdong River.

• Journal of the Korean Society for Marine Environment & Energy
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• v.13 no.3
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• pp.151-164
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• 2010

Field observations on the seasonal variations of environmental factors and phytoplankton community were carried out four times at 30 stations in the narrow strait between Yeosu and Dolsan Island of the Korean South Sea from September 2005 to May 2006. The ranges of water temperature, salinity and extinction coefficient in the surface waters were 5.6~26.3, 25.36~33.92 psu and 0.13~2.13, respectively. The water temperature measured higher at Gamak Bay in summer and spring. It measured higher at Yeosuhae Bay in autumn and winter. Salinity showed uniformity of distributions in almost all areas, except for an area near a sewage disposal outlet. Extinction coefficient indicated that the turbidity of Gamak Bay and the area near the sewage disposal outlet were higher than that of the Yeosuhae Bay. In the phytoplankton community were identified a total of 99 species belonging to 51 genera. The species composition showed itself to be various in summer and autumn, but poor in winter and spring with a high ratio of centric diatoms all the year round. Seasonal succession of dominant species were Skeletonema costatum and Chaetoceros curvisetus in summer, Eucampia zodiacus in autumn and winter, and Chaetoceros affinis and Thalassionema nitzschioides inspring. Standing crops of phytoplankton and Chlorophyll $\alpha$ concentration were greatly higher at Gamak Bay in summer with ranges of $0.2{\times}10^4\;cells\;L^{-1}$ to $296{\times}10^4\;L^{-1}$, and $1.94\;L^{-1}$ to $22.12\;L^{-1}$, respectively. From the results of principal component analysis (PCA), the northern part of Dolsan Island was divided into two or three regions from the characteristics of marine environment and phytoplankton community.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.143-144
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• 2003

최근 서울을 포함한 수도권지역은 물론 그 지역의 풍하지역에서 조차도 오존오염이 지속적으로 악화되고 있는 실정이다. 이에 대해 보다 정확한 원인 규명 및 그에 따른 대책 수립을 위하여 많은 연구가 진행되고 있다. 광화학모델링은 오존오염의 원인 규명 및 대책수립을 위해 정확도 향상이 요구된다. 본 연구에서는 광화학모델인 MODELS-3/CMAQ(1999)을 적용하여 수도권지역에서 빈번히 발생하는 2002년 하계 오존 고농도 현상을 모사하였다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.11a
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• pp.334-336
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• 2002

최근 이십여년 동안 대기 중에 존재하는 저분자량 카르복실산의 역할에 대한 관심이 증가되어 왔다. 주로 아세트산과 포름산으로 존재하는 저분자량의 카르복실산은 대류권의 여기저기에 기체상으로 존재하거나, 수용액 상이나 혹은 에어로솔이나 입자상물질의 표면에 녹거나 흡착되어 있는 형태로 존재한다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2009.10a
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• pp.616-617
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• 2009

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1999.10a
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• pp.143-144
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• 1999

1950년대 이후 구미 각국에서 수집된 대부분의 독성학적, 역학적 연구조사자료에 따르면 흡연과 관련한 발병률 및 사망률의 주요 원인이 흡연 당사자의 직접흡연에 의한 것으로 보고되어 왔다. .그러나 최근 들어 담배연기에 대한 비흡연자의 비자의적인 노출 즉, 환경담배연기(Environmental Tobacco Smoke, 이하 ETS)로 인한 보건학적 위해성에 대한 논란이 제기되면서 간접흡연은 새로운 사회문제로 대두되고 있다(Repace, 1980; Surgeon General, 1986).(중략)