• 한국해양학회지
• /
• v.29 no.2
• /
• pp.145-151
• /
• 1994

Investigations on distributions of bacterial abundance and production in the mideast part of the Yellow Sea were made in August and October, 1991 as a part of study of "The Exploitation Research of Marine Resources on the Yellow Sea". Here, we report spatial and temporal characteristics of distributions of bacteria in the mideast part of the Yellow Sea including data reported by Son (1989) for the same area. During the whole study period, bacterial abundance ranged from 0.5${\times}$10/SUP 8/ 1/SUP -1/ to 19${\times}$10/SUP 8/ 1/SUP -1/. Seasonal changes and the difference between two studies in bacterial abundance were less than 3.5 fold ar each station in the study area, except October, 1991. An interesting result was that bacterial abundances except October, 1991 were generally lower than those expected from the established relationship between chlorophyll and bacterial abundance in the oceans. For the bacterial abundance observed in October 1991, controlling factor(s) of bacteria might be different from the rest of study period. Bacterial production (0.1∼2.9ug C 1/SUP -1/ d/SUP -1/) comprised a small fraction (18${\pm}$11%) of primary production. Though data are limited, low bacterial abundances compared to chlorophyll concentration and low values of bacterial production to primary production seemed to occur in the mideast part of the Yellow Sea. Unravelling the causes of these phenomena would be necessary to understand the ecology of bacteria in the region.

• 한국해양학회지
• /
• v.22 no.2
• /
• pp.105-118
• /
• 1987

A series of anchor stations were occupied along the Keum EAstuary during six different periods of tidal and fluvial regimes. The results clearly show that the formation and evolution of the turbidity maximum play an important role in the sedimentary processes in this environment. The turbidity maximum in the Keum Estuary is primarily related to the tidal range at the mouth and is caused by the resuspension of bottom sediments. In this estuary, the turbidity maximum is not a permanent feature and shows semidiurnal, fortnightly and seasonal variations. Repetition of deposition and resuspension of fine sediments occur in response to the variation in current velocity associated with semidiurnal tidal cycles. The core of turbidity maximum shifts landward or seaward accordion to the flood-ebb succession. The turbidity maximum also shows a fortnightly variation in response to the spring-neap cycles. Thus, the turbidity maximum degenerates during neap-tide and regenerates during spring-tide. The freshwater discharge is also an important factor in the formation and destruction of the turbidity maximum. The increase in freshwater discharge in rainy season can create an ebb-dominant current pattern which enhances the seaward transport of suspended sediments, resulting in the shortening of residence time of suspended materials in the estuary. Thus, under this high discharge condition, the turbidity maximum exists only during spring-tide and starts to disappear as the tidal amplitude decreases.

• Korean Journal of Environment and Ecology
• /
• v.33 no.5
• /
• pp.587-595
• /
• 2019

This study analyzed the influence of the environmental factor of each vegetation type in an urban, mountainous park (Tangeumdae Park in Chungju) on air ion. The measuring points were divided according to the tree species, diameter at breast height, crown density, and layered structure, and the meteorological factors and the air ion were measured. The results of the measurement showed the average generation of positive ions of $610.90{\pm}50.27ea/cm^3$, the average generation of negative ions of $723.58{\pm}64.25ea/cm^3$, and the air ion index of $1.19{\pm}0.10$. The results of the analysis, according to the vegetation type, are as follows. Firstly, the air ion varied according to the species, the chest diameter at breast height, and the layered structure, and was analyzed to be statistically significant. Secondly, the air ion and the vegetation type showed a positive correlation with the species, diameter at breast height, crown density, and layered structure. The cation showed a negative correlation with the species, diameter at breast height, and the crown density, and the anion showed a positive correlation with the species, the diameter at breast height, crown density, and layered structure. Thirdly, the ion index in ridges had a higher correlation with the vegetation type than the meteorological factors. In detail, the correlation was higher in the species > layered structure > crown density > diameter at breast height. This study had the limitation of evaluating air ions in the ridge. Therefore, future studies on air ion should consider both terrain structure and vegetation type and analyze the seasonal changes and comparison.

• Journal of Korean Society of Water and Wastewater
• /
• v.35 no.5
• /
• pp.323-334
• /
• 2021

Pilot-scale coagulation and sedimentation processes were operated to investigate the T-P (Total phosphorus) removal efficiency. A multiple regression model was also derived to predict the water quality improvement effect with river water characteristics. The inflow rates for the pilot-scale facility were 157-576 m³/day, and the coagulant doses were in the range of 13.7-58.5 mg/L (average 38.9 mg/L) for PAC (Poly alum chloride) and 16.5-62.1 mg/L (average 36.0 mg/L) for alum. The results found that the influent BOD (Biochemical oxygen demand) and T-P concentrations were 4.9 mg/L and 0.115 mg/L, and the removal efficiencies were 52.7% and 59.4%, respectively. T-P removal efficiencies on wet weather days were higher by 10% than dry weather days because influent solids influenced T-P's coagulation process. The pH of river water was 6.9-7.8, and the average pH was 7.3. Although the pH variation was not significant, the trend showed that the treatment efficiency of T-P and PO₄-P removal increased. Thus, the pH range considered in this study seems to be appropriate for the coagulation process, which is essential for phosphorous removal. The T-P removal efficiencies were 19.6-93.3% (average 59.2%) for PAC and 16.4-98.5%(average 55.9%) for alum; thus, both coagulants showed similar results. Furthermore, the average coagulant doses were similar at 42.4 mg/L for PAC and 41.3 mg/L for alum. When the T-P concentration of the effluent was compared by the [Al]/[P] ratio, the phosphorus concentration of the treated water decreased with an increasing [Al]/[P] ratio, and the lowest T-P concentration range appeared at the [Al]/[P] ratio of 10-30. A seasonal multiple regression analysis equations were derived from the relationships between 10 independent and dependent variables (T-P concentration of effluent). This study could help lake water quality maintenance, reduce eutrophication, and improve direction settings for urban planning, especially plans related to developing waterfront cities.

• Journal of Wetlands Research
• /
• v.21 no.3
• /
• pp.191-198
• /
• 2019

High impervious surfaces increase the surface runoff during rainfall and reduces the underground infiltration thereby leading to water cycle distortion. The distortion of water cycle causes various urban environmental problems such as urban flooding, drought, water pollutant due to non-point pollution runoff, and water ecosystem damage. Climate change intensified seasonal biases in urban rainfall and affected urban microclimate, thereby increasing the intensity and frequency of urban floods and droughts. Low impact development(LID) technology has been applied to various purposes as a technique to reduce urban environmental problems caused by water by restoring the natural water cycle in the city. This study evaluated the contribution of hydrologic characteristics and water cycle recovery after LID application using long-term monitoring results of various LID technology applied in urban areas. Based on the results, the high retention and infiltration rate of the LID facility was found to contribute significantly to peak flow reduction and runoff delay during rainfall. The average runoff reduction effect was more than 60% at the LID facility. The surface area of the LID facility area ratio(SA/CA) was evaluated as an important factor affecting peak flow reduction and runoff delay effect.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
• /
• v.32 no.3
• /
• pp.116-135
• /
• 2019

Objectives : The purpose of this study is to analyze how purpura and vasculitis have been treated with Korean medicine and potentially to present with future direction of research and treatment. Methods : We searched clinical studies from the Korean databases including Oriental medicine Advanced Searching Integrated System(OASIS), Korean Traditional Knowledge Portal(KTKP), National Discovery for Science Leader(NDSL), Research Information Sharing Service(RISS), using keywords related to "Purpura" and "Vasculitis" from January 2000 to May 2019. Results : A total of 20 studies were selected for analysis. More than half of the patients provided with detailed information were under 19 year-olds, and upper respiratory infection, stress and fatigue, seasonal factor were among the most frequently stated as predisposing factors. Among many treatment modalities, herbal medicine was the most frequently used, followed by acupuncture and herbal acupuncture. 23 basic herbal medicine formulas were retrieved from 20 articles, most frequently used being Guibi-tang(歸脾湯加味), Samul-tang(四物湯加味) and Yukmijihwang-tang(六味地黃湯加味). In total, 122 Korean medicine herbs were used, most frequently used herbs being Glycyrrhizae Radix et Rhizoma(甘草), Angelicae Gigantis Radix(當歸), Poria Sclerotium(茯?) and Paeoniae Radix(芍藥). By its category, herbs were mostly classified into Tonyfying and replenishing medicinal(補益藥), Heat-clearing medicinal(淸熱藥) and Exterior-releasing medicinal(解表藥). Patients with total treatment period of 3 months or under were 2/3 of all cases provided with detailed information. Follow up periods were short in general with only 6 cases of over 6 months. The primary motive of patients to receive Korean medicine treatments was unresponsiveness or adverse effects of western medication. Conclusion : Through this literature review, we could find out tendencies of Korean medicine treatments of purpura and vasculitis up to date and some points that may have clinical significance.

• Journal of Environmental Impact Assessment
• /
• v.27 no.6
• /
• pp.704-716
• /
• 2018

The aim of this study is to examine the characteristics analysis of the discharge and water quality based on TPLMS (Total Pollution Load Management System) in the Jinwi River unit basin, and to propose a management plan by selecting the point that needs improvement of water quality in order to achieve the target water quality. We evaluated the discharge and water quality characteristics, statistical analysis, daily delivery load and daily delivery density, grade classification, for 14 total pollution load site's from 2014 to 2016 year in Jinwi river unit basin. The average discharge of Jinwi river unit basin is $22.411m^3/s$ and discharge of Hwangguji River is 32.8% and the water quality characteristics along the tributary river were clarified spatially. As the result, it was analyzed that Seongeun River is an indirect indicator of organic pollutants, Gwanri River is a seasonal factor, Osan River and Hwangguji River both affect water quality. Estimation of delivered pollutant loads at the HG-3 site was 6,470.4 BOD kg/day, 6,846.7 TN kg/day and delivered pollutant loads density increased to $220.9BOD\;kg/day/km^2$, $22.4TP\;kg/day/km^2$ at the HG-4 site. This result demonstrates that the total pollution load site needed to improve water quality of the Jinwi River unit basin was HG-3 site.

• Particle and aerosol research
• /
• v.14 no.4
• /
• pp.135-144
• /
• 2018

Based on a two-year measurement data, major sources for the ambient carbonaceous aerosols at the Anmyeon Global Atmosphere Watch (GAW) station were identified by using the Positive Matrix Factorization (PMF) model. The particulate matter less than or equal to $2.5{\mu}m$ in aerodynamic diameter (PM2.5) aerosols were sampled between June 2015 to May 2017 and carbonaceous species including ~80 organic compounds were analyzed. When the number of factors was 5 or 6, the performance evaluation parameters showed the best results, With 6 factor case, the characteristics of transported factors were clearer. The 6 factors were identified with various analyses including chemical characteristics and air parcel movement analysis. The 6 factors with their relative contributions were (1) anthropogenic Secondary Organic Aerosols (SOA) (10.3%), (2) biogenic sources (24.8%), (3) local biomass burning (26.4%), (4) transported biomass burning (7.3%), (5) combustion related sources (12.0%), and (6) transported sources (19.2%). The air parcel movement analysis result and seasonal variation of the contribution of these factors also supported the identification of these factors. Thus, the Anmyeon Island GAW station has been affected by both regional and local sources for the carbonaceous aerosols.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.21 no.4
• /
• pp.158-174
• /
• 2018

The leaf area index (LAI) is a major factor explaining the photosynthesis of vegetation, evapotranspiration, and energy exchange between the earth surface and atmosphere, and there have been studies on accurate and applicable LAI estimation methods. This study aimed to investigate the relationship between the actual LAI data, UAV image-based vegetation index, canopy height and satellite image (Sentinel-2) LAI and to present an effective LAI estimation method using UAV. As a result, among the six vegetation indices in this study, NDRE ($R^2=0.496$) and CIRE ($R^2=0.443$), which contained red-edge band, showed a high correlation. The application of the canopy height model data to the vegetation index improved the explanatory power of the LAI. In addition, in the case of NDVI, the saturation problem caused by the linear relationship with LAI was addressed. In this study, it was possible to estimate high resolution LAI using UAV images. It is expected that the applicability of such data will be improved if calibration and correction steps are carried out for various vegetation and seasonal images.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.40 no.1
• /
• pp.51-66
• /
• 2022

SST (Sea Surface Temperature) is based on the atmosphere-ocean interaction, one of the most important mechanisms for the Earth system. Because it is a crucial oceanic and meteorological factor for understanding climate change, gap-free grid data at a specific spatial and temporal resolution is beneficial in SST studies. This paper examined the production of daily SST grid maps from 137 stations in 2020 through the ordinary kriging with variogram optimization and their accuracy assessment. The variogram optimization was achieved by WLS (Weighted Least Squares) method, and the blind tests for the interpolation accuracy assessment were conducted by an objective and spatially unbiased sampling scheme. The four-round blind tests showed a pretty high accuracy: a root mean square error between 0.995 and 1.035℃ and a correlation coefficient between 0.981 and 0.982. In terms of season, the accuracy in summer was a bit lower, presumably because of the abrupt change in SST affected by the typhoon. The accuracy was better in the far seas than in the near seas. West Sea showed better accuracy than East or South Sea. It is because the semi-enclosed sea in the near seas can have different physical characteristics. The seasonal and regional factors should be considered for accuracy improvement in future work, and the improved SST can be a member of the SST ensemble around South Korea.