• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.3
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• pp.437-446
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• 1998

The general pattern of the hydrographic conditions and tidal front of the northern coastal area of Cheju Island is investigated using the CTD observation data and a stratification parameter V ($J/m^3$) in $1991\~1993$. 1. The sea water of the northern coastal area of Cheju Island has a lower temperature and higher salinity than that in the central area of the Strait, and local temperature and salinity fronts appears frequently around this area. It seems that they are caused by the upwelling and the tidal front as well as a local topography. 2. A saddle-like distribution of temperature and salinity is formed in the Cheju Strait almost every month with relation to mixing of the different water masses. 3. In the northern coastal area of Cheju Island the stratification parameter V ($J/m^3$) was ranged from 8.4 to 209.8 $J/m^3$ in June, 201.9 to 634.9 $J/m^3$ in August, 0.18 to 680 $J/m^3$ in September, and $2.7\~462\;J/m^3$ in October, respectively. The tidal front was often formed around the place where the horizontal variation of the depth is very large and the potential energy with 10$J/m^3$ appears roughly along 50 m isobath.

• Journal of Wetlands Research
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• v.19 no.4
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• pp.383-392
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• 2017

In 2013, August and September(early) as summer and October and November as Fall the probe of eutrophication has been done at 22 sampling points from the entrance of Danghang Bay (Jinhae Bay) to Geosan reservoir. In Danghang Bay, total chlorophyll(TChl) concentration of summer was 3.7 times higher than that of fall, and sampling points closer to the center showed 1.8 times higher concentrations than sampling points near the fringe where fresh water encountered. Eutrophication Index(EI) exceeded 1 at all sampling points in Danghang Bay during summer and fall, and if other conditions for algae growth met there was a possibility red tide to bloom at any place. There was a tendency of EI to gradually increase moving up from the entrance of bay to the inner side during summer and fall. Especially there was a sudden increase by 2.3 times higher at sampling points of 13~22 (planned region as Madong reservoir) than at other points during fall. Nitrogen was a limiting nutrient for growth of algae during summer and fall in Danghang Bay, but phosphorus was a limiting nutrient during summer rainy season. During summer and fall, multiple linear regression analysis between EI and COD, DIN, and DIP showed a significant positive relationship and that DIP was the most effective variable. Whereas multiple linear regression analysis between TChl and COD, DIN, DIP, and DSi showed a significant positive relationship and that DIP was also the most effective variable during summer. There was no significant correlation between TChl and the other parameters during fall.

• Korean Journal of Environment and Ecology
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• v.28 no.4
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• pp.472-483
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• 2014

Major cities have strengthened their efforts to improve the environmental function of the urban forest through aspects of quantity and quality. Yet, it is difficult to propose both long-term improvement and management policy direction continuously due to a lack of evaluating method that social needs could be reflected. After all, effective strengthening of the function of an urban forest, composed of social and biotic environments, is essential to create evaluation criteria. Such data reflects a quantity variation and identifies the distribution and habitation of biotic sources as well. An assessment of utilization possibilities presents such values as a green connectivity, an ecological healthiness, and usage and access opportunities. Consequently, this research was executed to create an urban forest sustainability index that proposes a management and policy direction based on the evaluation of quantity and quality aspects. This study was processed by the following steps: a degree of importance of ecological aspect, a sub-classification index choice, and an examination of adequacy. This research was conducted from premises that urban forest had another functions comparisons to a natural forest. As a result, a criteria of sustainability should be considered to evaluate an ecological aspect, as well as the social and management aspects regarding human disturbance. This research is designed to develop an evaluation index for ecological aspect. In order to evaluate the ecological healthiness of an urban forest, a vegetation index considers aspects of related rarity, damage possibility, naturalness, area, and diversity. In a wildbird index-related study, forest duration and area were selected. Finally, a variance analysis is presented, inclusive of stability, naturalness, diversity, potentiality, and possibility of wildlife inhabitation, which is indicative of an urban forest sustainability index.

• Journal of Life Science
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• v.20 no.8
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• pp.1201-1206
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• 2010

We performed a comparative analysis using a Real-time PCR (Polymerase Chain Reaction) and LC/MS (Liquid-Chromatograph/Mass Spectrometer) method in order to detect microcystin in environmental sources. Among the three different primer sets tested for microcystin using three positive strains of Microcystis aeruginosa by Real-time PCR assay, only TOX2P/TOX2M primer pairs were able to detect Microcystis aeruginosa. According to the results of a survey carried out from June 2009 to September 2009, 11 out of 11 (100%) raw water samples were were found to have microcystin when the Real-Time PCR and LC/MS method was used, with total microcystin concentration ranging from 5.98~219.0 ${\mu}g/l$. A microcystin removal treatment process was used to ensure entire removal, by passing it through a BAC filtration step. It was concluded that real-time PCR assay can be used to estimate micrucystin detection more rapidly and easily than the LC/MS method.

• 전기의세계
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• v.43 no.1
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• pp.13-19
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• 1994

전자식 안정기는 최근 에너지 절약 정책과 관련하여 조명기기분야의 관심의 대상이 되었고, 절전 효율이 높은 고품질의 전자식 안정기에 대한 연구 개발 및 보급이 점점 더 확대되고 있는 추세이다. 일반적으로 전자식 안정기는 수십 KHz의 고주파에서 형광등을 구동시킴으로써 빛의 깜박거림과 가청잡음이 없으며, 저주파(60Hz)에서 사용하는 재래식 안정기(choke coil 방식)에 비해 높은 절전 효과를 얻을 수 있다[1-4]. 특히, 빌딩 사무실의 경우 낮에도 창가의 형광등이 켜져 있어서 막대한 전력을 낭비하고 있는 실정이므로, 일조량에 따른 자동 전력 조절이 가능한 전자식 형광등의 출현이 기대되고 있다. 전자식 안정기의 보급 확대를 위해서는 절전 효과 뿐만 아니라, 품질 문제, 수명 문제등을 고려하여야 하는 바, 예를 들면 순간 점등으로 방전초기의 sputtering 현상에 의한 lamp의 수명 단축, 미소 입력전압 변동에 따른 급격한 광출력의 변화로 절전 효과의 상실과 이상동작에 의한 스위칭 소자의 파괴 현상, 고주파 스위칭시 발생되는 전력손실과 noise등에 대한 대책이 요구되고 있다. 이러한 점을 개선하기 위해 추가되는 회로는 전자식 안정기 시스템을 더욱 복잡하게 만들고, 경제적으로 원가 부담을 주기 때문ㅇ 고품질의 전자식 안정기를 보급하는데 어려운 점으로 부각되고 있다. 본 고에서는 이러한 문제를 해결하기 위하여 조광기능을 포함한 다양한 제어회로와 보호회로를 조광기능을 포함한 다양한 제어회로와 보호회로를 1 chip에 수용하는 고품질의 전자식 안정기 제어용 집적회로에 대해서 기술하고자 한다.되어 나아갈 기술의 조류에도 부합하는 형태라 하겠다. 그러나 이 방식은 기 언급한 바와 같이 분산처리를 관장하는 운영체계의 개발에 상당한 고전이 따르리라 보여지며, 또한 보다 상세한 연구가 선행되어야 하겠지만 개발된 상용의 통신 프로토콜로서는 병렬처리의 성능을 극대화 하기에는 여러가지 제약이 있을 것으로 예측된다.기기들이 어떻게 응용되고 있는지 살펴보기로 하자. real informations would be available. Results are compared with those of optimal power flows.기능시험을 완료했으며 실제 line-of-sight(LOS) 시스템 구현에 적용중이다. 시대를 살아 갈 회원들이다. '컨텐츠의 시대'가 개막되는 것이며, 신세기통신과 SK텔레콤은 선의의 경쟁 과 협력을 통해 이동인터넷 서비스의 컨텐츠를 개발해 나가게 될 것이다. 3배가 높았다. 효소 활성에 필수적인 물의 양에 따른 DIAION WA30의 라세미화 효율에 관하여 실험한 결과, 물의 양이 증가할수록 그 효율은 감소하였다. DIAION WA30을 라세미화 촉매로 사용하여 아이소옥탄 내에서 라세믹 나프록센 2,2,2-트리플로로에틸 씨오에스터의 효소적 DKR 반응을 수행해 보았다. 그 결과 DIAION WA30을 사용하지 않은 경우에 비해 반응 전환율과 생성물의 광학 순도는 급격히 향상되었다. 전통적 광학분할 반응의 최대 50%라는 전환율의 제한이 본 연구에서 찾은 DIAION WA30을 첨가함으로써 성공적으로 극복되었다. 또한 고체 염기촉매인 DIAION WA30의 사용은 라세미화 촉매의

• Ecology and Resilient Infrastructure
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• v.7 no.1
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• pp.72-81
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• 2020

Blooms of the small centric diatom Stephanodiscus is quite occasional in winter season in temperate freshwater ecosystems. Often, it leads to degradation of water quality and affects quality of supplied drinking water. In previous studies, naphthoquinone (NQ) compounds have been shown to be effective and selective for controlling winter bloom species Stephanodiscus hantzschii. We conducted a 5 ton scale mesocosm experiment to investigate the effects of NQ on native Stephanodiscus sp. collected from Nakdonggang River in water. After treatment with NQ 4-6 compound (0.2 μM), the cell density of Stephanodiscus sp. was rapidly reduced from 5 × 10³ cells mL^-1 to 0.2 × 10³ cells mL^-1 for 10 days. Additionally, NQ 4-6 compound did not affect physicochemical factors (water temperature, dissolved oxygen, pH, conductivity, nutrients) and biological factors (bacteria, heterotrophic nanoflagellates, zooplankton). Therefore, these findings suggest that the NQ 4-6 compound has potential as an alternative algicidal substances to effectively mitigate natural Stephanodiscus sp. blooms, and the application of NQ 4-6 compound will restore the healthy aquatic ecosystems.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.3
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• pp.364-372
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• 1995

On the outbreak of paralytic shellfish poisoning in April 1993 in most of shellfish harvesting areas in Jinhae Bay, Korea, to clarify the toxin production of causative organism Alexandrium species, 19 axenic clonal isolates established from the benthic resting cysts in three different stations of those culture grounds were subjected to PSP toxin analysis by HPLC. Individual toxin content per cell was highly variable among the strains isolated from a sampling area and originated from an individual cyst. Average toxin contents in those areas revealed higher values of 54-70 fmol/cell. Toxin profiles included C1/C2(epiGTX8/GTX8), GTX1/GTX4 and neoSTX as the major components, and GTX2/GTX3, GTX5, C4, dcSTX and STX as the minor or sporadic ones. neoSTX on the dominant toxins showed not only most diverse compositional changes comprising $5-54 mol\%$ ranges but also no detection on the half of the strains examined, which were implicated in arising of heterogeneity with a genetic trait within a geographical region. When average toxin composition was compared, carbamate toxins comprised large proportions of $57\%,\;54\%\;and\;67\%$ as total toxin in St. 1, St. 2 and St. 4, respectively. These results suggested that an extensive paralytic shellfish toxification in Jinhae Bay could be largely due to the production of highly potent carbamate toxins in the causative dinoflagellate Alexandrium species.

• Archives of design research
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• v.19 no.4 s.66
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• pp.111-120
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• 2006

These days, contemporary people's interest in culture is higher than ever, and in response to such a current trend, each country is making efforts to search for its identity in various areas, and conducting research to compare its culture with that of other countries. The culture of a region does not develop independently or spontaneously, but it changes and evolves in connection with neighboring countries or cultures. Thus, in order to understand our own cultural characteristics properly, we need not only to make an in-depth study in our own culture but also to compare it with other cultures and understand their similarities and differences dearly. From old times, Korea, China and Japan have had great influences on one another through active socio cultural exchange and at the same time they have their own unique cultural characteristics. Unfortunately, however, the distinguished identity of Korean culture has not been recognized properly. The present study purposed to classify Korean, Chinese and Japanese traditional furniture from the $14th{\sim}19th$ century by type, and compare their characteristics by type as well as their general formative characteristics. This research is expected to improve our objective understanding of our own culture. Furthermore, it will provide a ground for reinterpreting our culture to distinguish Korean culture from Oriental culture.

• Journal of Life Science
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• v.18 no.12
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• pp.1671-1678
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• 2008

We investigated the effect of the turbid water on the phytoplankton community in the 4 sites of Imha reservoir. The turbidity of water was proportional to the concentrations of $SiO_2$-Si. Therefore, as the turbidity of water grow, the concentration of $SiO_2$-Si increased. And the both the turbidity of water and the concentrations of $SiO_2$-Si were increased as the water run deep. The concentration of chlorophyll-a decreased as the depth of water increased. Seventy phytoplankton taxa were identified and the most abundant group was Chlorophyceae consisting of 32 taxa (46%), and Cyanophyceae and Bacillariophyceae consisted of 12 taxa (17%). And Euglenophyceae, Synulophyceae, Cryptophyceae and Dinophyceae consisted of 6 taxa (9%), 4 taxa (6%), 3 taxa (4%) and 1 taxon (1%), respectively in Imha reservoir. The concentrations of phytoplankton were increased according to the turbidity of water because of the high amount of organic nutrition which is presented with turbid water. And especially, the concentrations of nitrogen increased easily because of the weak binding to the soil particle. In conclusion, total nitrogen and $SiO_2$-Si flowed into the Imha reservoir with soil particle, and these inorganic nutritions affect the growth of algae.

• Korean Journal of Ecology and Environment
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• v.42 no.3
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• pp.404-406
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• 2009

This study note wished to introduce special-purpose ship for algae removal that is developed by core technology of our country. The ship is consisted of main frame and adjuvant that can attach and detach as cross (+) shape of a character. The characteristics of ship are super light weight and low draft. That is consisted of four devices as suction, collection, filtration and recovering units. Among these, filtration used screen filter (mesh size 30 ${\mu}m$). Also, can separate and remove water and algae by compression air participle notion. Percentage of moisture content of concentrated algal particle was 85%. Water parted with algae finally is exhausted to water area. Removal efficiency that compare by chlorophyll-$\alpha$ concentration was about 57% (inflow: 83.2 ${\mu}g\;L^{-1}$, outflow: 35.8 $[\mu}g\;L^{-1}$) without physical and chemical pretreatment. Forward, need to achieve effect test in various conditions (algal biomass, flow etc.) for efficiency and technological elevation of exclusion device. We wished to contribute in presuppression system construction of massive algal development that manage blue-green algae occurrence area effectively, and prevents spread as lower part of reservoir.