• 한국농림기상학회지
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• 제20권3호
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• pp.252-261
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• 2018

이 연구는 월평균 기상자료를 이용하여 일 최고기온, 일 최저기온을 생성하는 방법을 개발하기 위하여 진행되었다. 전국 23개 기상관서의 과거 30년간의 일기상자료를 분석하여 일 최고기온 및 일 최저기온의 연간 변동 경향을 나타내는 모수(중심값($\hat{U}$), 진폭(C), 편이(T))와 일간 변동을 반영하는 모수(A, B)를 탐색하였다. 그 중 중심값은 지점간의 연 평균자료로부터 도출하였고, 중심값을 제외한 모수들은 전국 평균을 기상생성과정에 적용하였다. 먼저 강우발생 유무에 따라 일 기상자료를 생성한 후 월 자료를 이용하여 보정하고 마지막으로 일 최고기온 및 일 최저기온을 생성하였다. 이 방법으로 전체 23개 지역에 대하여 월별로 생성하였을 때 전체 월별 분포의 95% 이상 관측된 분포와 유사한 일 자료를 생성할 수 있었다. 또 이 방법에 의해 과거 자료와 유사한 생장도일(Growing Degree Day)를 생성할 수 있었고, 조사대상이 아닌 지역에도 충분히 적용할 수 있었다. 이 방법은 기후변화시나리오 등 월 자료가 확보되어 있는 경우에 일기상자료를 생성하는데 유용할 것으로 판단되었다.

• 수산해양기술연구
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• 제52권2호
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• pp.130-140
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• 2016

This study analyzed annual catch trend during 45 years and monthly catch of the least 10 years (2005~2014) for chub mackerel caught in the Korean coastal waters. To determine fishing status of chub mackerel, fork length measurements were conducted at least twice every week for 100 individuals randomly selected at the Busan Cooperative Fish Market from January of 2012 to December of 2014; and biological characteristics and proximate composition (moisture, protein, fat, ash) were analyzed by length class (I~IV) on a monthly basis from January to December of 2014. Monthly catch trend showed low level below 5,000 mt from February to July, whereas high level above 15,000 mt from October to December. For the period between 2012 and 2014, annual average catch proportion of juvenile were relatively high at 68.1%, 53.1% and 53.2% from January to April, before spawning season, while those were low at 21.5%, 20.7% and 29.12% from June to November. As for the change in the proximate composition per 100 g of muscle, protein and ash did not change much by seasons and length class, whereas fat and moisture contents showed large fluctuations and complementary relationship between the two factors. Regardless of length class, monthly average fat content, containing Omega-3, showed the lowest at 7.18 g in April and highest at 19.27 g in December, which exhibited 2.6 times difference from one another. Regardless of fishing seasons, fat content by length class were 19.06 g for the class I and 6.43 g for the class IV, which showed three times difference. Fat contents of the class I were high at 26.97 g and 27.19 g in November and December, while low at 8.37 g and 9.99 g in April and May. Especially, fat contents from January to May were 5.0 g, which was the lowest. Therefore, it is expected that consumer could indirectly contribute fisheries management through their understanding and wise consumption based on fishing status and fluctuation of proximate composition.

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권7호
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• pp.121-134
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• 2015

Spatial and temporal changes in algal population in Yongdam reservoir and ecological factors that induced the changes in the size and composition of algal population were investigated by monthly sampling at ten locations in the reservoir. Nutritional state of the reservoir was identified to be phosphorus-limited with nitrogen to phosphorus (N : P) ratio much greater than 17 in most samples. Algal population was dominated by three taxonomic groups, diatoms, chlorophytes and cyanobacteria. Although explosive algal growth was not observed in the summer, algal population showed transition with time of the dominant algal type from diatoms in the winter to cyanobacteria in the summer. Chlorophyta was not the dominant group in the reservoir although they maintained relatively stable number of cells in the reservoir and showed increase in population from March to May. The application of statistical methods revealed that the factors inducing changes in cell number of each group were water temperature for diatoms and cyanobacteria and phosphorus concentration for chlorophyte. Fluctuation of cyanobacterial population was mainly observed near the inlet of tributaries while diatoms showed higher variation inside the reservoir.

• 수산해양기술연구
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• 제53권2호
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• pp.142-151
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• 2017

The fluctuation in the abundance and species composition of fish was investigated using gape net in Dolsan District of Yeosu Korea from July 2015 to April 2016. A total of 1,331 fishes were sampled and classified into 30 orders, 42 families, and 53 species. The dominant orders are Perciformes including 21 famailies and 24 species, followed by Scorpaeniformes including 7 families and 13 species, and Clueiformes including 6 families and 6 species. Among the 53 fish species collected, Engraulis japonicus was the most frequent species occupying 43.5%, followed by Argyrosomus argentatus (23.8%), and Leiognathus nuchalis (22.4%). The monthly diversity, evenness, and richness index were 1.83-2.90, 0.76-0.95 and 3.06-6.40.

• 환경생물
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• 제21권4호
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• pp.342-351
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• 2003

The southern rough shrimp Trachysalambria curvirostris (Stimpson) was monthly sampled from the coastal area of Yeosu, Korea from June 2000 to May 2001 and its stomach contents were investigated. Mysids and amphipods were the most dominant prey, comprising >40% of the diet in both % occurrence and % abundance. In particular, mysids were most important food without regard to seasons, size classes, or sexes. The abundance and occurrence composition of food items showed a seasonal fluctuation: mysids and amphipods were the predominant prey items in spring (33.8%), summer (41.1%), autumn (43.9%), and winter (49.2%). For small-sized shrimps (＞25 mm CL), mysids and amphipods consist of more than 45% of its food in both % abundance and % occurrence. For large-sized shrimps (>25 mm CL), these were clearly dominant. The quantities and items of food did not differ in both genders, which mainly fed on mysids and amphipods. The trophic diversity and equality of diet varied with seasons and size classes. The diet diversity for smaller shrimps was highest in spring, while that for the larger shrimp lowest in winter. Also, the mandibular structure of Trachysalambria curvirostris indicates that the species is carnivorous.

• 생물환경조절학회지
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• 제13권2호
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• pp.96-101
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• 2004

This study was conducted to determine the daily application rate and amount of N and K with fertigation during different growth stages in semi-forcing culture of cucumber plants (Cucumis sativus L. cv. Eunseongbaekdadagi). The diagnostic criteria for N and K also investigated based on petiole sap analysis. The dry weight increased slowly until 30 days after transplanting. The highest dry weights were observed at 60 days after planting, then it decreased. As the plant grew, the contents of N and K in the petiole sap and fruit of cucumber decreased. The daily uptake of N and K were highly correlated with the growing days. The $NO_3$ concentrations in petiole sap were in the range from 3,500 to 4,500 mgㆍ$L^{-1}$ in the early growth stage, but those were in the range from 2,000 to 3,000 mgㆍ$L^{-1}$ after then. However, K concentration in petiole sap were in the rang from 5,000 to 7,000 mgㆍ$L^{-1}$ The fluctuation in petiole sap concentration of K was severe in the monthly fertigation and moderate in the daily fertigation. The fertigation by petiole sap diagnosis forced EC of soil to be low and yield to increase compared to the control.

• 한국환경과학회지
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• 제25권3호
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• pp.447-456
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• 2016

Access to clean and affordable water is one of the fundamental human rights because water is essential to life and a foundation for socioeconomic development of any country in the world. Despite the efforts to secure water supply in Burundi, the amount of water supplied by public utilities does not meet the demand of the population because population keeps increasing with fluctuation of weather conditions. This study selected north Bujumbura that is a sprawling new residential area in the western part of Burundi as a case to investigate the potential of rainwater harvesting in meeting water demand of the country. Based on a long-term average monthly precipitation in the region, the rainwater harvesting potential was assessed as a function of roof sizes, number of households, and runoff coefficients of roof materials. For the entire region of north Bujumbura, the current water supply capacity of the local water company combined with the rainwater harvesting potential resulted in the water surplus of $468,604.1m^3/yr$. Although three communes among them still showed water deficit in dry season, they still got help from rainwater to relieve their water shortage. This suggests that at the regional scale, proper storages and water quality control for harvestable rainwater could contribute to relieving the regional water shortage and allow the population growth.

• 무역상무연구
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• 제75권
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• pp.95-116
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• 2017

The global financial crisis has slowed overall growth in the global economy. In addition, uncertainty is increasing in the world economy due to the Trade protectionism, sluggish world trade, and a rise in the rate of interest caused by expansion of fiscal spending by major countries. In this study, we analyzed various factors affecting the container import and export volume, which has a high correlation with export and import of commodities in international trade. In particular, we will examine how exchange rate fluctuations and domestic and overseas economic conditions affect container imports and exports. For the empirical analysis, monthly time series data were used from January 2000 to January 2017. We use the Error Correction Model (VECM) for the empirical analysis and the GARCH model for the exchange rate fluctuation. As a result, container export and import volume had a negative relationship with exchange rate and exchange rate volatility, which had a positive effect on domestic and international economic conditions. However, the effects are different before and after the financial crisis.

• 수산해양기술연구
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• 제34권2호
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• pp.105-116
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• 1998

This paper, examines the relationship between water temperatures and fishing conditions of common squid by the squid angling fishery from June to September in 1993-1995. The condition of the common squid fishing largely depended on the fluctuation of water temperature in the coastal area of Gampo. Monthly mean water temperatures during June m September in 1993 and 1994 were relatively higher than those in 1995 in Gampo area. But the values between July and August in 1995 were about 5$^{\circ}C$ lower than those in 1993 and 1995. Coefficients of variation (CV) of water temperature showed the lowest value during July ~ September in 1993, however, the highest value was observed in July and August in 1994. Catch per unit effort (CPUE ; kg/angling) showed a peak with 73.7kg in 1993 when the CV was low. On the other hand, the lowest CPUE of 39.6kg was observed in 1994 when the CV was high. It was concluded that the high stability of water temperatures and the weak strength of cold water have caused the good fishing conditions of common squid.

• 한국수산과학회지
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• 제43권5호
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• pp.510-520
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• 2010

This study investigated the community structure and seasonal variation of the fish assemblages on Jangbong tidal flat, Incheon, Korea. Fish were collected monthly using a small otter trawl from November 1999 to January 2001. Thirty-six fish species were recorded, with a mean density of 185 individuals and biomass of 2,594.3 gWWt. The most abundant species by number were Johnius grypotus (23.7%), Acanthogobius hasta (17.8%), and Cynoglossus joyneri (10.7%), while the dominant species by catch weight were Acanthogobius hasta (21.2%), Sebastes schlegeli (16.2%), J. grypotus (14.0%), and C. joyneri (10.8%). Cluster analysis and non-metric multi-dimensional scaling (nMDS) were applied to assess the seasonal fluctuation in the fish assemblages. Based on the result of the cluster analysis and nMDS ordination, the faunal group could be divided into cold- and warm-water specialist groups. The cold-water specialists included A. hasta, Acanthogobius luridus, Triaenopogon barbatus, Tridentiger trigonocephalus, and Liza haematocheila. The warm-water specialists were J. grypotus, C. joyneri, S. schlegeli, and Hexagrammos otakii. In conclusion, the community structure showed a distinct seasonal trend, which seemed to be related to the seasonal fluctuations in water temperature.