• Korean Journal of Remote Sensing
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• v.28 no.5
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• pp.531-548
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• 2012

To identify Cochlodinium polykrikoides red tide from non-red tide water (satellite high chlorophyll waters) in the South Sea of Korea (SSK), we improved a spectral classification method proposed by Son et al.(2011) for the world first Geostationary Ocean Color Imager (GOCI). C. polykrikoides blooms and non-red tide waters were classified based on four different criteria. The first step revealed that the radiance peaks of potential red tide water occurred at 555 and 680 nm (fluorescence peak). The second step separated optically different waters that were influenced by relatively low and high contributions of colored dissolved organic matter (CDOM) (including detritus) to chlorophyll. The third and fourth steps discriminated red tide water from non-red tide water based on the blue-to-green ratio, respectively. After applying the red tide classification, the spectral response of C. polykrikoides red tide water, which is influenced by pigment concentration as well as CDOM (detritus), showed different slopes for the blue and green bands (lower slope at blue bands and higher slope at green bands). The opposite result was found for non-red tide water. This modified spectral classification method for GOCI led to increase user accuracy for C. polykrikoides and non-red tide blooms and provided a more reliable and robust identification of red tides over a wide range of oceanic environments than was possible using chlorophyll a concentration, or proposed red tide detection algorithms. Maps of C. polykrikoides red tide in SSK outlined patches of red tide covering the area near Naro-do and Tongyeong during the end of July and early of August, 2012 and extending into from Wan-do and Geoje-do during the middle of August, 2012.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.4
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• pp.289-293
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• 2013

The changes of phytoplankton community in downstream of the Nakdong River from 2002 to 2012 was investigated. Phytoplankton biomass (chlorophyll-a concentration) was gradually increased, but dominant species cell number was gradually decreased. In changes of percentage of dominant species cell number from 2002 to 2012, Diatoms was gradually decreased, but blue-green algae was gradually increased. In changes of annual percentage of dominant period, Diatoms showed high percentage from November to May, and dominant period (%) of diatoms was 56%~74% from June to September, also dominant period of diatoms was about 300 days every year. Percentage of dominant species cell number and dominant period of blue-green algae was 68%~94% and 26%~ 36% from June to September, respectively. And green-algae showed low percentage from April to September. In the transition patterns of diatoms and blue-green algae, Stephanodiscus spp. was the highest dominant species, from December to May, and Aulacoseira spp. and Fragilaria spp. were showed high dominant percentage from May to October. In the case of blue-green algae, Microcystis spp. was the highest dominant species, from May to November, also in the case of green algae, Actinastrum spp., Pediastrum spp., Micractinium spp. and Pandorina spp. were dominant species from April to September.

• Journal of Environmental Science International
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• v.21 no.8
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• pp.1015-1021
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• 2012

Formation of disinfection by-products (DBPs) including trihalomethans (THMs), haloacetic acid (HAAs), haloacetonitriles (HANs) and others from chlorination of algogenic organic matter (AOM) of Microcystis sp., a blue-green algae. AOM of Microcystis sp. exhibited a high potential for DBPs formation. HAAs formation potential was higher than THMs and HANs formation potential. The percentages of dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) formation potential were 43.4% and 51.4% in the total HAAs formation potential. In the case of HANs formation potential, percentage of dichloroacetonitrile (DCAN) formation potential was 97.7%. Other DBPs were aldehydes and nitriles such as acetaldehyde, methylene chloride, isobutyronitrile, cyclobutanecarbonitrile, pentanenitrile, benzaldehyde, propanal, 2-methyl, benzyl chloride, (2-chloroethyl)-benzene, benzyl nitrile, 2-probenenitrile and hexanal.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.18 no.2
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• pp.61-67
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• 1982

Optical properties of sea water were studied in the southern sea of Korea, based on ten oceanographic stations in July, 1980. Submarine daylight intensity was measured at intervals of 5m depth in the upper 70m layer by using the underwater irradiameter (Kahlsico # 268 WA 360). The mean absorption coefficients of the sea water were shown as 0.102 (0.066~0.137), 0.119 (0.069~0.154), 0.091 (0.054~.0123), and 0.095 (0.056~0.129) for clear, red, green, and blue color respectively. The transparency ranged from 13 to 25 meters (mean 17.1 m). The mean water color in this area was 3.9 (3-5) in Forel scales. The relation between absorption coefficient (k) and transparency (D) was k=1.17/D, k=2.01/D, k=1.52/D, and k=1.60/D for clear, red, green, and blue color respectively. The rates of light penetration for clear, red, green, and blue color in four different depths were computed with reference to the surface light intensity respectively. The mean rates of light penetration in proportion to depths were as follows; clear : 57.3%(5m), 20.82%(15m), 5.16%(30m), 0.94%(50m). red : 52.2%(5m), 15.99%(15m), 2.99%(30m), 0.39%(50m). green : 60.9%(5m), 24.51%(15m), 7.11%(30m), 1.56%(50m). blue : 59.4%(5m), 22.92%(15m), 6.09%(30m), 1.29%(50m).

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.412-412
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• 2022

지속가능한 물관리를 위해서는 강우, 수문학적 반응의 동적 순환과 생공업 및 농업 기반시설과 같은 관리 조치에 사용되는 물을 포함한 가용수(Available Water)의 시공간적 영향을 파악할 수 있어야 한다. 가용수의 구성요소를 파악하기 위해 블루워터와 그린워터의 개념이 제안되었다. 블루워터는 강수로 인해 형성된 지표수, 지하수 및 호수·저수지의 저류량을 포함하며, 그린워터는 강수로부터 불포화 토양층에 저장된 토양수분과 수역, 초목에서 대기 중으로 방출되는 증발산을 말한다. 블루워터와 그린워터를 산정하기 위해서는 동적 수자원과 인적 요소에 의존되는 수자원을 정확하게 구별해야 하며 물 가용성 평가를 용이하게 하는 통합 기반 개념의 수문학적 모델이 필요하다. 따라서 본 연구에서는 5대강을 대상으로 각 유역의 가용수량의 변화를 파악하기 위해 각 유역별 블루워터와 그린워터를 평가하고자 하였다. 5대강 유역의 장기간 변화와 광범위한 분석을 위해 SWAT(Soil and Water Assessment Tool) 모형의 수문모델링 결과를 활용하였다. SWAT 모형의 신뢰성 있는 수문 검보정을 위해 전체 기간(2005~2020) 중 모형의 보정(2005~2009) 및 검증(2010~2017)기간을 설정하였으며, 각 유역의 다목적댐과 다기능 보의 실측방류량을 이용하여 댐 운영모의를 고려하였다. 검보정된 SWAT 결과를 활용하여 블루워터와 그린워터를 분류하였으며 가용수량을 평가하는 방법을 제시하였다.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.44 no.3
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• pp.174-183
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• 2008

In order to develop the substitutive materials for natural baits of swimming crab pots, the fluorescent characteristics of the baits were analyzed, and the preference of fluorescent dyes were investigated by the mean entrapped catch number to the pots through the water tank experiments and fishing experiments. On the investigation of fluorescent characteristics by the 5 kinds of baits, mackerel, krill, manila clam, pig's fat and chicken's head which were used in substitutive baits for test in the UV long wave(365nm) area, it showed clear blue fluorescence in the skin of mackerel, shell of krill, manila clam and bill of chicken's head, and green fluorescence in the mackerel s muscle and internals, and yellow fluorescence in the pig's fat and chicken's head. On the investigation of fluorescent characteristics by the bait cages in the UV short wave(254nm) and long wave(365nm) area, it showed each green, red and blue fluorescence in the cylinderical or hexahedral red plastic bait cages which were painted each green, red and blue fluorescence dyes, but it showed yellowish green flourescence in the cylinderical or hexahedral red plastic bait cage which was painted yellow fluorescent dye. On the preference investigation of the fluorescent dyes of swimming crabs by the 5 kinds of the bait cages which were put the mackerel in the non-fluorescent red plastic cage($RF_N$), red, yellow, green and blue fluorescent plastic cages(RF, YF, GF, BF) each, nonfluorescent red plastic cage($RF_N$) was entrapped mean 2.0(6.7%), but blue fluorescent plastic cage(BF) was mean 5.0(16.7%) and it was more 2.5 times comparing to $RF_N$, and red fluorescent cage(RF) was same level and green fluorescent cage(GF) was 50% of catch number comparing to $RF_N$, and yellow fluorescent cage(YF) was entrapped nothing(F 46.324, P < 0.05). On the investigation of the entrapped catch number to the pots which were put the mackerel in the blue fluorescent hexahedral plastic cage(HP) and blue fluorescent silicon mackerel model cage(SM), HP was mean 3.4(11.3%) and it was a little more comparing to SM which was entrapped mean 3.2(10.7%)(t 0.775, P > 0.05). Fishing experiments on the preference investigation of swimming crabs by the pots which were put in the non-fluorescent red plastic cage($RF_N$) and blue fluorescent plastic cage(BF) were conducted 3 times. Mean catching number and weight of $RF_N$ were 71.7 ind.(18.3%) and 16.9kg(64.3%), and those of BF were 93.0 ind.(23.1%) and 19.8kg(64.5%), respectively.

• 한국해양학회지
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• v.3 no.2
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• pp.55-62
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• 1968

The distributions of average water color and the transparency in the seas around Korea show two patterns: the one is the East Sea and the South Ses, the other is the Yellow Sea. In the East Sea and the South Sea, the water colors C$\sub$E/ in Forel scales change from green to greenish blue with distance x in miles from the seashore, an average color is bluish green, 3.7 in Forel scales, and the relationship is given by C$\sub$E/ = 5e$\^$-0.056.root.x; an average transparency is 15m and the transparency T$\sub$E/ shows following formula with distance x, E$\sub$E/=0.9.root.x+10. In the Yellow Sea, the water color C$\sub$Y/ changes from green yellow to bluish green with distance, an average color is light green, 5.6 in Forel scales, and the relationship is given by C$\sub$Y/= 8.5e$\^$-0.086.root.x; an average transparency is 7m, the farther it is from the seashore, the deeper transparency T$\sub$Y/ is as following, T$\sub$Y/=1.2 .root.x+1. Along the seashore, the transparency T$\sub$Y/ is only 10% that of the East Sea and the South Sea. The distributions of the water color and the transparency by depth change in values within the continental shelf. The water color in Forel scales decreases with the distance from the seashore and depth; the transparency increases with the distance and depth. They are caused by suspended particles, especially suspended clay, and it is the major factor in the change in color and transparency, particularly in the Yellow Sea. In September, the sea water is the clearest in the seas around Korea, transparency shows the maximum and water color the minimum in forel scales. The water color shows green yellow when transparency is 1m, green at 10m, and greenish blue at 20m. the relationship between the water color and the transparency shows an exponential distribution as following, C=9e$\^$-kT/, k=0.0625m$\^$-1/. This formula agrees with calculated formulas between the water color and the transparency from the emprircal formulas C$\sub$E/ and T$\sub$E/, C$\sub$Y/ and T$\sub$Y.

• Animal Bioscience
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• v.36 no.5
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• pp.731-739
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• 2023

Objective: This study was to evaluate the interaction of three different light-emitting diode (LED) light colors (white, green, and blue) and three intensities (5, 10, and 15 lx) on slaughter performance, meat quality and serum antioxidant capacity of broilers raised in three-layer cages. Methods: A total of 648 (8-days-old) male broiler chicks (Cobb-500) were randomly assigned in 3×3 factorially arranged treatments: three light colors (specifically, white, blue, and green) and three light intensities (namely, 5, 10, and 15 lx) for 35 days. Each treatment consisted of 6 replicates of 12 chicks. The test lasted for 35 days. Results: The semi-eviscerated weight percentage (SEWP) in 5 lx white was higher than that in 15 lx (p<0.01). The eviscerated weight percentage (EWP) (p<0.05) and water-loss percentage (WLP) (p<0.01) decreased in 10 lx white light than those in green light. Under blue light, the content of hypoxanthine (Hx) in muscle was lower than that under white and green light (p<0.01). The content of malondialdehyde (MDA) in 15 lx blue light was higher than that in 10 lx green light (p<0.05). Light color had an extremely significant effect on thigh muscle percentage, WLP, Hx, and crude protein content (p<0.01). Light intensity had a significant effect on SEWP (p<0.05), EWP (p<0.05), lightness (L^*) value (p<0.05), WLP (p<0.01), and the contents of superoxide dismutase (p<0.05), MDA (p<0.01), glutathione peroxidase (p<0.01). Conclusion: Using white LED light with 10 lx light intensity can significantly improve the chicken quality of caged Cobb broilers, improve the content of inosine acid in chicken breast and enhance the antioxidant capacity of the body. We suggest that the broiler farm can use 10 lx white LED light source for lighting in 8 to 42 days.

• Journal of Korean Society on Water Environment
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• v.38 no.4
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• pp.177-189
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• 2022

Nature-based Solutions (NbS) are defined as practical and technical approaches to restoring functioning ecosystems and biodiversity as a means to address socio-environmental challenges and provide human-nature co-benefits. This study reviews NbS-related literature to identify its key characteristics, techniques, and challenges for its application in climate-adaptive water management. The review finds that NbS has been commonly used as an umbrella term incorporating a wide range of existing ecosystem-based approaches such as low-impact development (LID), best management practices (BMP), forest landscape restoration (FLR), and blue-green infrastructure (BGI), rather than being a uniquely-situated practice. Its technical form and operation can vary significantly depending on the spatial scale (small versus large), objective (mitigation, adaptation, naturalization), and problem (water supply, quality, flooding). Commonly cited techniques include green spaces, permeable surfaces, wetlands, infiltration ponds, and riparian buffers in urban sites, while afforestation, floodplain restoration, and reed beds appear common in non- and less-urban settings. There is a greater lack of operational clarity for large-scale NbS than for small-scale NbS in urban areas. NbS can be a powerful tool that enables an integrated and coordinated action embracing not only water management, but also microclimate moderation, ecosystem conservation, and emissions reduction. This study points out the importance of developing decision-making guidelines that can inform practitioners of the selection, operation, and evaluation of NbS for specific sites. The absence of this framework is one of the obstacles to mainstreaming NbS for water management. More case studies are needed for empirical assessment of NbS.

• Korean Journal of Ecology and Environment
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• v.56 no.1
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• pp.14-35
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• 2023

Freshwater and brackish blue-green algae were collected at 43 freshwater and brackish sites (including lakes, ponds, swamps, streams, and rivers and estuaries) throughout South Korea from March 2017 to October 2018, and were identified using light microscopy. A total 223 taxa in freshwater and 230 taxa in brackish waters in 2017 and 274 taxa in fresh and brackish waters in 2018 were identified and among them, 20 taxa were unreported taxa of blue-green algae in Korea; The new recorded taxa were Aphanocapsa marina, Calothrix fusca f. durabilis, Calothrix littoralis, Calothrix parva, Chamaesiphon minimus, Chroococcidiopsis cubana, Chroococcidiopsis fissurarum, Coelosphaerium aerugineum, Dolichospermum mendotae, Eucapsis alpine, Gomphosphaeria cordiformis, Gomphosphaeria natans, Merismopedia danubiana, Lynbya aestuarii var. gaditana, Tolypothrix tenuis, Pseudocapsa maritima, Pseudocapsa sphaerica, Pseudophormidium tenue, Trichodesmus sp. and Woronichinia elorantae.