• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.640-647
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• 2017

The need for an efficient sampling technique to collect aquatic organisms has risen with the increase of interest in rice paddy fields, which have been recognized as important ecosystems supporting biodiversity. In the present study, a submerged funnel trap used with the assistance of attracting agents (fish meal and chemical light) was designed as an easy, objective and quantitative tool for collecting aquatic organisms in the rice paddy fields. The preference for collecting aquatic organisms as a means for attracting agents was analyzed using a generalized linear mixed model. Also, based on the data of previous research, we compared the community composition of the aquatic macroinvertebrates, which were collected using the quadrat method, and newly designed submerged funnel traps, by analyzing non-metric multidimensional scaling. The results showed that the catching efficiency of 18 of the total 65 taxa was affected by the attracting agents. 12 taxa including Pomacea canaliculata, Hippeutis cantori, Austropeplea ollula, Erpobdella lineata, Ostracoda spp. Branchinella kugenumaensis, Hydaticus grammicus, Rhantus pulverosus, Chironomidae spp., Rana nigromaculata, Cobitidae spp. etc., favored fish meal and 6 taxa including Ischnura asiatica, Coenagrionidae spp. Sternolophus rufipes etc., were attracted by chemical light. The submerged funnel trap used as a measurement tool for biodiversity was less applicable than the quadrat method; however, it was more effective for the selective collection of specific taxa. We expect that this newly designed trap can be a simple and quantitative method for collecting aquatic organisms, and could be used for long term and extensive surveys in rice paddy fields in the future.

• Korean Journal of Environmental Agriculture
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• v.8 no.1
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• pp.17-29
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• 1989

This study was conducted to evaluate the behavior in the water and the impact on aquatic organisms following aerial application of two insecticides in the forest, cyfluthrin and trichlorfon, to control the alder leaf beetle. As active ingredients, 25g of cyfluthrin and 536g of trichlorfon per ha were diluted seperately into 30L of tap water, and applied with a helicopter to the study areas. A model stream study was also conducted in a stream located adjacent to the study area in order to confirm the impact of insecticides on aquatic invertebrates. Cyfluthrin residues in water were $0.62{\mu}g/L$ (1st. application) and $78{\mu}g/L$ (2nd application) immediately after spraying. and decreased, to a non-detectable level after one day, while trichlorfon residue increased to $30.7{\mu}g/L$ one day after spraying and fluctuated for 22th day depending on precipitation after spraying. Cyfluthrin application rapidly increased the number of some drifting aquatic invertebrates during 24-hour period immediately after spraying, but had no effects on the other aquatic organisms such as fish and zooplankton. The largest increase in the number of drifting organisms following application of cyfluthrin was shown by Ephemeroptera, and followed by Trichoptera, Coleoptera, and Diptera. However, trichlorfon little affected the number of drifting aquatic invertebrates and zooplankton population.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.1136-1142
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• 2012

The roles of paddy fields are re-evaluated as an artificial wetland. Although 44% of total aquatic invertebrates in South Korea are observed in a rice paddy, information of their distribution and characteristics of habitat use is limited yet. This study was carried out to provide information and characterizing distribution of community of aquatic invertebrates using a rice paddy through the South Korea. Aquatic invertebrates were collected at 284 sites of a rice paddy in South Korea from June to August, 2005, 2006 and 2007. We grouped sampling sites according to its species and population of aquatic invertebrates using a non-metric multidimensional scaling (NMDS). Total 21 orders 60 families 114 species were collected from a rice paddy. Coleoptera (25%), Heteroptera (17%), Diptera (17%) and Odonata (12%) were observed. Aquatic invertebrates were classified into three groups (Group 1: Gangwon, Gyeonggi and Chungbuk; Group 2: Chungnam, Jeonbuk, Jeonnam and Jeju; Group 3: Gyeongbuk and Kyeongnam). In Group 1, Muljarus japonicas distributed mainly Gangwondo and Chungbuk. In Group 2, Sigara nigroventralis and S. substriata were mainly observed. In Group 3, higher density of Daphnia sp. and Chironomidae gen. spp. was found in the southern part of Korea.

• Korean Journal of Ecology and Environment
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• v.41 no.3
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• pp.320-330
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• 2008

For twenty-nine aquatic insect taxa common to mountain headwater streams in central Korean peninsula, body length-dry mass and -ash free dry mass relationships were developed by using a natural log transformed power function. Most of the predicted mass at length of this study was rather similar to those of other studies. Taxa with higher predicted mass at length than predicted by others tend to have soft exoskeleton and move by stretching and contracting their body. Ash rate in average was 10% of dry mass and was not significantly different among functional feeding groups.

• Journal of Forest and Environmental Science
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• v.15 no.1
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• pp.89-97
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• 1999

This study was carried out to obtain basic data on the kinds of aquatic insects and their living conditions in the mountain stream. The investigation was done in Bongmyung stream. Experimental Forest, Kangwon National University on aquatic insects, anions and river-bed materials. The results are as follows. 1. At every plot surveyed, diversity index, richness index and evenness index of aquatic insects appeared higher at upper stream than at lower stream in erosion control dam. 2. Anion concentrations were almost the same in plots A, B, C, D and E, but plot F at the lower stream showed 1.5 to 89 times higher concentration than the others. 3. In river-bed materials analysed, particle diameter was bigger at the upper stream than at the lower stream. At the down stream of erosion control dam showed high pebble composition ratio. 4. The number of aquatic insects showed the negative relation with the anion concentration and the positive one with the size of river-bed materials. Especially, they were affected much by the distribution chart of boulder.

• Journal of the Korean Society for information Management
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• v.11 no.1
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• pp.167-187
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• 1994

This project is to design and to implement an cornputenzed acquisition system by structured analysis technique for the Yomi university library. In result of desgmng, we added three subsystems, whlch are accession control, account, and print out system, to DOBIS/E acquisition system because we found that our DOBIS/E acquision system is able to use as we do ordenng and receiving in traditional process. DOBIS/E system and three added subsystems is closely related, and allow acquisition librarians to work more efficiently than before.

• Proceedings of the Korean Society for Information Management Conference
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• 2005.08a
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• pp.205-212
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• 2005

본 연구의 목적은 전문도서관인 공무원교육원 도서관의 공동수서정책을 위해 이용자의 요구를 인용문헌분석을 통해 파악하고자 하였다. 이을 위해 3개 공무원교육원의 주이용자인 장기교육생의 인용문헌을 자료의 유형분석, 자료의 최신성 분석, 인용문헌수 분석, 외국문헌 이용현황과 핵심자료를 파악하고자 하여 공무원교육원 도서관의 공동수서정책에 반영하고자 하였다. 그 결과 형태별로는 연구보고서의 인용율이 가장 높았으며, 평균인용건수를 분석한 결과, 교육수료보고서의 1인당 평균인용건수는 29.42권으로 조사되었다. 발행시기별로 분석한 결과, 출판 후2${\sim}$5년 내의 자료를 40.6%로 가장 많이 인용하는 것으로 조사되었으며, 언어별 분석 결과, 국내서로 기술된 문헌의 인용율은 90.1%로 조사되었다. 핵심자료를 파악한 결과 단행본의 최대 피인용문헌빈도(3회 이상)는 155권 이었으며, 학술지는 112종, 통계자료는 34권이었다.

• Journal for History of Mathematics
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• v.18 no.3
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• pp.1-24
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• 2005

Although indeterminate equations were dealt in Jiu zhang suan shu and then in Sun zi suan fing and Zhang Giu Jian suan Jing in China, they did not get any substantial development until Qin Jiu Shao introduced da yan shu in his great book Shu shu jiu zhang which solves goneral systems of linear congruences. We first investigate his da yan shu and then study the history of indeterminate equations in Chosun Dynasty. Further, we compare Qin's da yan shu with that in San Hak Jung Eui written by Chosun mathematician Nam Byung Gil.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.235-235
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• 2019

감조하천 구간에서의 수면경사 및 유속분포 등 흐름특성은 조석의 영향으로 자연하천과 달리 매우 복잡하고 다양한 형태를 보이고 있다. 또한 하류에서 상류로 조류 유입시 해침으로 인한 염분도 상승으로 수서생물은 담수종에서 기수종 및 해수종으로 천이되고 있다. 섬진강 하구의 대표적인 수서생물인 재첩은 염분도 상승에 따라 폐각을 닫고 모래층으로 이동하는 특성을 보이고 있다. 이러한 관점에서 본 연구는 감조하천 구간에서의 취수장의 취수 규모에 따른 염분도 변화특성을 살펴보고, 하구 수서생물생활환경에 적합한 염분도를 유지할 수 있는 합리적인 취수장 운영방안을 마련하는 데 있다. 이를 위해 과거 취수장 상류의 유출량에 따른 취수규모별 하구 염분도 변화 특성을 분석하였다.

• Korean Journal of Environment and Ecology
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• v.22 no.4
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• pp.420-426
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• 2008

This study compared and analyzed EPT ratio, EPT richness and EPT number(number of species and individuals) of a total of 9 selected sites individually using EPT-group of aquatic insects in Musim stream, also compared similarity ratio between the sampling sites using UPGMA(Unweighted Paired Group Method using Arithmetic average) based on analysis subsequent to species structure of aquatic insects, and compared and analyzed a functional feeding groups(FFGs) of aquatic insects based on stream order. As a result, the aquatic insect group of 2,269 individuals is classified as 71 species, 36 families, and 8 orders, and EPT ratio and EPT richness at sites 3(0.72 and 3.89, respectively) were found to be relatively higher than those at the other sites; by contrast, those at site 9(0.03 and 0.09, respectively) were relatively low. EPT number of species and individuals was found to be lowest at site 9. As a result of UPGMA analysis, the sampling sites in Musim stream were divided into three groups, including A1(site 1, 7, 8), A2(site 2, 3, 4, 5, 6) and B(site 9). According to the results of FFGs, there was not shown specific difference in the number of functional feeding groups by each sites; however, there appeared a little more shredders and scrappers in the upper and mid stream comparing to other sampling sites while collector-filterers and collector-gatherers were found to be dominant in number in the lower stream. According to this research result, the sampling sites in Musim stream were found to have an effect on not only EPT richness, EPT ratio, and EPT number but also FFGs structure.