• Proceedings of the Korea Contents Association Conference
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• 2014.06a
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• pp.83-84
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• 2014

For hydrologic applications, lake levels is very important. As a first step in developing a remote-sensing based approach, lake stage estimation using remote sensing was proposed with the SRTM data from February 2000, which was providing a one-time snapshot. After several steps using contouring, masking, and CED, it was found that iterative contour fitting to a lake outline provided the outstanding result with the operator's decision. If the lake size is large enough, a constant meter of the difference removal due to bias found by Bhang et al. (2007) might be useful for more accurate estimations for the methods. A lake-level snapshot using SRTM data could provide estimates within 0.5 m level of accuracy for large lakes (> $10km^2$) with contouring. Also, even if the processing algorithm is complex, the accuracy was reliable. Overall, we confirmed that this study would provide useful information to ameliorate the quality of the SAR-derived DEMs specifically for water areas and if more expanded, SAR images can fruit result in water monitoring.

• Journal of Ecology and Environment
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• v.37 no.4
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• pp.257-270
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• 2014

In a survey of periphytic and benthic diatoms in Korea, diatoms of genus Stauroneis were found to be widely distributed over freshwaters, rivers and streams, lakes and reservoir, wetlands in lowland and mountain areas, and even subaerial terrestrial habitats. However, it is clear that Stauroneis diatoms prefer peatlands, which can be more or less acidic or oligotrophic environments in freshwaters. In this study, Staurones diatoms were collected mainly from mountain peatlands. Twenty five taxa were confirmed to be species, while some specimens remain unidentified. Approximately twenty species have been reported in Korea in the past, but these are largely S. anceps Ehremberg sensu lato, S. phoenicenteron (Nitzsch) Eherenberg sensu lato, and their infraspecies variety or forma. Sixteen of the twenty five Stauroneis taxa found in this survey are reported for the first time in Korea.

• Journal of Ecology and Environment
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• v.37 no.4
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• pp.365-378
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• 2014

This study was carried out on freshwater chlorococcal green algae in ponds, swamps, reservoirs, lakes and rivers (290 sites) from May 2012 to January 2014. The family Radiococaceae was identified and classified into 3 genera, 12 species and 1 variety at 23 sites. These taxa were Eutetramorus. nygaardii, E. tetraporus, E. planctonicus, E. fottii, E. globosus, E. polycoccus, Coenocystis planctonica, C. planctonica var. hercynica, C. micrococca, C. subcylindrica, Gloeocystis baneergattensis, G. papuana, and G. polydermatica. These taxa may or not had remnants of the cell wall in the colonial gelatinous envelope for a short time. Of these, 2 taxa are newly recorded in Korea from this study: 1) C. micrococca and 2) G. polydermatica.

• Journal of Ecology and Environment
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• v.37 no.4
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• pp.351-363
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• 2014

A study on fresh-water green coccoid algae was carried out at ponds, swamps, reservoirs, lakes and rivers (290 sites) from May 2011 to January 2014. In this study, 4 genera and 13 taxa of the family Radiococaceae having the remnants of cell wall existing for a long time in the colonial gelatinous envelope are classified and identified from 24 sites. Many taxa of this family, however, have not been recorded in Korea yet. Of these 13 taxa, 5 taxa are newly recorded in Korea by this study: 1) Schizochlamydella solitaria, 2) Thorakochloris planktonica, 3) Radiococcus bavaricus, 4) R. nimbatus, and 5) R. planktonicus.

• Korean Journal of Environmental Biology
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• v.35 no.3
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• pp.305-318
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• 2017

Freshwater algae (green algae, blue-green algae and flagellated algae) were collected at 103 freshwater sites (including lakes, ponds, swamps, streams, and rivers) throughout South Korea March 2015-October 2016, and were identified using light microscopy. A total of 345 taxa in 2015 and 329 taxa in 2016 were identified and among them, 6 taxa in 2015 and 8 taxa in 2016 were new recorded species in Korea; The new recorded species were Characiopsis malleolus in Xanthophyceae, Phacus mammillatus in Euglenophyceae, Epipyxis utriculus and Lagynion ampullaceum in Chrysophyceae, Bicosoeca planctonica in Bicosoecophyceae and Salpingoeca frequentissima in Choanoflagellatea in 2015, and were Ankistrodesmus bernardii and Quadrigula korsikovii in Chlorophyceae, Didymocystis planctonica in Treubouxiophyceae, Spirulina nodosa, Raphidiopsis curvata and Geitlerinema claricentrosum in Cyanophyceae and Lagynion macrotrachelum in Chrysophyceae, Bicosoeca oculata in Bicosoecophyceae and Salpingeoca rosetta in Choanoflagellatea in 2016.

• Journal of Ecology and Environment
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• v.36 no.4
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• pp.267-271
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• 2013

To examine the density effect and food concentration in the competitive output of two Bosmina species, the population growths of Bosmina fatalis were investigated by manipulating the density of B. longirostris and the concentration of algae. The B. fatalis density did not increase in conditions with abundant B. longirostris regardless of the food concentrations. The B. fatalis increased only at low densities of B. longirostris with high food concentrations. Based on the current results, a possible mechanism underlying the seasonal shift from B. longirostris to B. fatalis in Japanese eutrophic lakes will be explored below.

• Animal Systematics, Evolution and Diversity
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• v.3 no.2
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• pp.175-207
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• 1987

A taxonomic Study was carried out on the freshwater cladocerans from Korea during the period from August 1985 to May 1987. Materials consist of both the specimens deposited at Department of Zoology, College of Natural Sciences, Seoul National University and those collected at the freshwater regions such as rivers, lakes, ponds, bogs, rice fields, etc. During the period. As a result of examining the speciemens collected at the 123 locations in South Korea, 31 species of 7 families were identified and classified. In this paper, the authors submit the figures of the 31 species, of which the following 13 species were descirbed as hitherto unrecorded species in Korea : Diaphanosoma Leuchtenbergianum Fisher, 1858 : Simocephalus vetulus 9O.F.Mller, 1776) ; S. esxpinosus (koch, 1841); Ceriodaphnia reticulata (Jurine, 1820) ; Scapholeberis mucronata (O.F. Mller, 1785) ; Moina weismanni Ishikawa, 1896 : Ilyocryptus agilis Kurz, 1878 ; Biapertura affinis (Leydig, 1860) : Camptocercus rectirostris Schodler, 1862 ; alona costata Sars, 1862 ; Disparalona rostrata (Koch, 1841); Pseudochydorus globosus (Barird, 1843) ; Leptodora kindtii(Focke, 1844)

• Animal Systematics, Evolution and Diversity
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• v.5 no.2
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• pp.159-171
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• 1989

Tardigrades were collected in freshwater habitats, such as rivers, streams , lakes , ponds and rice paddies at 19 different localities in Korea, during the period of May 1986 -January 1988, and seven species were identified. Dactylobiotus dispar, Macrobiotus hufellandi, M. richtersi, Hypsibius convergnes, H. dujardini, Isohypsibius granulifer, and Pseudobiotus megalonix, Five species of these except D. disparand H. dujardini, are new to Korea, which are fully described and illustrated.

• Journal of Korean Society of Water and Wastewater
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• v.12 no.2
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• pp.59-66
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• 1998

The feasibility of usage of sludge from water treatment plant and chalk from schools and institutes was investigated to remove the phosphorus in the lakes which induce the eutrophication every year. In this study phosphorus removal efficiencies of sludge and chalk were investigated by changing various factors. Higher phosphorus removal efficiency using larger particle size of chalk was observed which means that the surface area is not an important factor in removing phosphorus in aqueous phase. The proper shaking time and temperature were 2 hours and $25^{\circ}C$, respectively. The removal efficiency using sludge from water treatment plant was almost 100%, which is similar to those of CaO and $Ca(OH)_2$. It means that sludge can be reused in removing phosphorus. It was also found that chalk was better in removing phosphorus under alkaline condition and sludge was better under acidic condition. About 75% phosphorus removal efficiency was observed using sludge from the water sample in Lake Sihwa.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.247-253
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• 2006

본고는 주요 댐호수의 휴양가치를 댐호수의 특성별로 도출하고자 실제로 댐호수를 선택한 행위를 분석하고, 아울러 선택실험을 통해 가상적으로 설정된 특성을 가진 댐을 방문할지를 선택하도록 하여 그 결과를 분석하기도 하였다. 또한 현시선호된 선택과 진술선호선택을 모두 결합하여 분석하는 기법도 사용하였다. 분석결과 진술선호자료와 현시선호자료간의 이질성이 상당한 것으로 나타났으나 두 자료를 결합함으로써 모든 특성변수들이 만족도에 미치는 영향이 직관과 부합되도록 도출되었다. 댐호수의 수량과 수질 모두가 레크리에이션 가치에 영향을 미치는 것으로 나타났으나, 특히 수질개선의 편익 증가효과가 매우 크다는 것이 확인되었다. 그 외에도 홍보관, 주변 숙박시설 및 음식점, 인근 휴양지와의 연계성 등도 휴양가치 증가에 영향을 미치는 주요 변수로 파악되었다.