• Korean Journal of Remote Sensing
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• v.37 no.5_2
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• pp.1307-1315
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• 2021

The Changjiang Diluted Water (CDW) spreads over the East China Sea every summer and significantly affects the sea surface salinity changes in the seas around Jeju Island and the southern coast of Korea peninsula. Sometimes its effect extends to the eastern coast of Korea peninsula through the Korea Strait. Specifically, the CDW has a significant impact on marine physics and ecology and causes damage to fisheries and aquaculture. However, due to the limited field surveys, continuous observation of the CDW in the East China Sea is practically difficult. Many studies have been conducted using satellite measurements to monitor CDW distribution in near-real time. In this study, an algorithm for estimating Sea Surface Salinity (SSS) in the East China Sea was developed using the Geostationary Ocean Color Imager (GOCI). The Multilayer Perceptron Neural Network (MPNN) method was employed for developing an algorithm, and Soil Moisture Active Passive (SMAP) SSS data was selected for the output. In the previous study, an algorithm for estimating SSS using GOCI was trained by 2016 observation data. By comparison, the train data period was extended from 2015 to 2020 to improve the algorithm performance. The validation results with the National Institute of Fisheries Science (NIFS) serial oceanographic observation data from 2011 to 2019 show 0.61 of coefficient of determination (R²) and 1.08 psu of Root Mean Square Errors (RMSE). This study was carried out to develop an algorithm for monitoring the surface salinity of the East China Sea using GOCI and is expected to contribute to the development of the algorithm for estimating SSS by using GOCI-II.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.22 no.4
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• pp.151-171
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• 2017

Most of oceanic current maps in the secondary school science and earth science textbooks have been made on the base of extensive in-situ measurements conducted by Japanese oceanographers during 1930s. According to up-to-date scientific knowledge on the currents in the Yellow Sea and the East China Sea (YES), such maps have significant errors and are likely to cause misconceptions to students, thus new schematic map of ocean currents is needed. The currents in the YES change seasonally due to relatively shallow water depths, complex terrain, winds, and tides. These factors make it difficult to construct a unified ocean current map of the YES. Sixteen major items, such as the flow of the Kuroshio Current into the East China Sea and its northward path, the origin of the Tsushima Warm Current and its path into the Korea Strait, the path of Taiwan Warm Current, the Jeju Warm Current, the runoff pattern of the Yangtze River flow, the routes of the northward Yellow Sea Warm Current, the Chinese Coastal Current, and the West Korea Coastal Current off the west coast of the Korean Peninsula, were selected to produce the schematic current map. Review of previous scientific researches, in-depth discussions through academic conferences, expert discussions, and consultations for three years since 2014 enabled us to produce the final ocean current maps for the YES after many revisions. Considering the complexity of the ocean currents, we made seven ocean current maps: two representative current patterns in summer and winter, seasonal current maps for upper layer and lower layer in summer and winter, and one representative surface current map. It is expected that the representative maps of the YES, connected to the current maps of the East Sea and the Northwest Pacific Ocean, would be widely utilized for diverse purposes in the secondary-school textbooks as well as high-level educational purposes and even for scientific scholarly experts.

• Korean Journal of Environmental Biology
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• v.37 no.4
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• pp.707-718
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• 2019

Ecklonia cava Kjellman, which has recently gained popularity due to the spread of farming techniques, is expected to be developed in various varieties in the future. There exist increased needs for research on the basis of natural populations and inter-regional morphological variations. We compared the morphology of the aquaculture and natural populations from 16 coastal areas in Korea. The 18 traits found suitable for distinguishing varieties were selected from 14 measurement traits and 4 ratios related to the main morphology and characteristics of primary blade, secondary blade, and stipe. In the cluster analysis, Janggil (E4) and Sorok (S7) showed significant differences from those of the same coastal region. Two groups, including Suyou (Q6, Q8, and Q10) which was the second year of farming, of the rest of the populations from East sea and southern coast were distinguished. Three populations of Jeju were divided into a regional group. In the principal component analysis (PCA), a large number of populations from East sea and Southern coast appeared in the center with aquaculture populations. PC1 and PC2 associated with traits of secondary blade index, stipe length and diameter, stipe length/primary blade length, primary blade length and width, secondary blade number, secondary blade length and width, divided E4, S7 and populations of Jeju region. As a result, the 18 characters of this study were found to be useful as criteria for discrimination of populations with significant differences in each coastal region, and these populations were expected to be candidates for new varieties.

• The Korean Journal of Malacology
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• v.23 no.2
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• pp.217-225
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• 2007

This study was conducted to estimate the general genetic parameters, heritabilities, and genetic and phenotypic correlations on growth-related traits by studying multiple trait animal model in two Korean abalone species, Haliotis discus hannai and H. discus discus. The data was collected from the records of 3,795 individuals produced from 54 sires and 74 dams in Haliotis discus hannai and 399 individuals produced from 7 sires and 7 dams in Haliotis discus discus. The data was evaluated by the Genetics and Breeding Research Center, National Fisheries Research & Development Institute (NFRDI). Genetic parameters were estimated for two abalone species raised in Bukjeju branch, NFRDI, from May 20 to November 1, 2004. The heritability estimates for growth traits of shell length, shell width and body weight obtained from restricted maximum likelihood (REML) were ranging from 0.73 to 0.78 in Haliotis discus hannai, and from 0.87 to 0.89 in H. discus discus. The heritabilities for shell shape and condition factor were ranging from 0.17 to 0.20 in Haliotis discus hannai, and from 0.01 to 0.45 in H. discus discus. Genetic and phenotypic correlations were over than 0.96 between shell parameters and weight in both of abalone subspecies, indicating that breeding for weight gains could successfully be achieved by selecting for shell length.