• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.2
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• pp.117-124
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• 2010

To examine the effective use of seaweeds, sea tangle (Laminaria japonica) was extracted with water and the resultant extracts were fermented with Saccharomyces cerevisiae. Four strains of S. cerevisiae were cultured in aqueous extracts from sea tangle. S. cerevisiae SC-2, which was isolated from a traditional Korean fermented food (Meju), was selected for further study based on the results of a sensory evaluation. No significant differences in proximate compositions, such as moisture, crude protein, crude fat, and crude ash, of the sea tangle extracts before and after fermentation were observed. The reducing sugar decreased as the fermentation period increased, and the contents of some free amino acids were also affected by S. cerevisiae SC-2 fermentation. However, the content of glutamic acid, which is a major taste compound in sea tangle extract, was not affected by fermentation for up to 36 hr by the SC-2 strain. To determine the antioxidant activity of fermented sea tangle extract (fermented for 36 hr by SC-2 strain), the radical scavenging activities of 1,1-diphenyl-2-picrylhydrazyl (DPPH), superoxide, and nitric oxide were investigated and xanthin oxidase inhibition assay was performed. The antioxidant activity increased by 8 to 35%. The greatest enhancement of antioxidant activity was seen in the superoxide radical scavenging assay with $100\;{\mu}g/mL$ of raw and fermented sea tangle extract. The anti-inflammatory activity of fermented sea tangle extract was also enhanced. The fermented sea tangle extract showed 34.2% inhibitory activity against nitric oxide synthesis versus 11.9% for raw sea tangle extract at $100\;{\mu}g/mL$ concentration. These results suggest that fermented aqueous extracts from sea tangle are a useful resources.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.24 no.2
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• pp.159-165
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• 2006

This paper deals with the estimation of geostrophic current using the sea surface topography calculated from the geoidal height from EGM96 geopotential model and the mean sea surface height from CLS_SHOM mean sea surface model. The CLS_SHOM model was developed using the altimetry data set. The estimation of geostrophic current is available in the characteristic research of ocean in many country, while for East Sea a few studies were done. The goal of this study is basically to provide the characteristics of geostrophic current in East Sea. The results show that the mean sea surface topography (SST) in East Sea is about 0.37 m and the mean geostrophic velocity is -0.028 m/sec. The Pacific water enters into the East Sea through the Korea Strait and after passing the strait, this inflow splits into two branches: one flows northward along the Korean coast and another outflows into Pacific ocean through Tsugaru and Soya strait passing the east-northeastward along the Japanese outer shelf, and outflows into Okhotsk ocean.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.41 no.2
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• pp.94-101
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• 2008

In Korean waters, there are two color types (blue and purple) of the blue crab Portunus trituberculatus. The blue type is common, but the ratio of the purple type has increased in landings. To determine whether there were significant morphometric or genetic differences between the blue and purple types, crabs caught from the West Sea of Korea were examined. Based on covariance analysis, there were significant differences in 1 of 10 morphometric characteristics of males between the two types, in none of the ten characteristics for females. Using amplified fragment length polymorphism (AFLP) DNA fingerprinting, no specific AFLP marker was detected for each type. The heterozygosity and genetic diversity were very low. Analyses of pairwise distance, the Fst index, and genetic similarity revealed similar results, with very low genetic differentiation. Therefore, there is no significant difference between blue and purple types of the crab from the West Sea of Korea, and the two types in the West Sea can be managed as one stock.

• Journal of the Korean earth science society
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• v.23 no.5
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• pp.436-441
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• 2002

This study is concerned with the sea breeze criterion and climatological characteristics of the short-time sea breeze in the Gangneung coastal area. The sea breeze criteria in this area are listed here. First, the fact of the sea breeze blowing was considered to be a change of wind direction from land to sea and vice versa without terrain effect like easterly wind. Second, the sea breeze of which continuous time 1-hour or 2-hour was selected. Then the climatological characteristics of the short-time sea breeze were analyzed using the meterological data from a 10-year(1988${\sim}$1997) period. The climatological characteristics which were analyzed for the short-time sea breeze consist of the frequency, onset time, wind direction speed and temperature. Finally, this study will be helpful in meteorological application through the climatological characteristics of sea breeze along the east coast as well as Gangneung Airport.

• Atmosphere
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• v.29 no.2
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• pp.149-164
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• 2019

The purpose of this study is to introduce the improvement of current operational climate prediction system of KMA and to compare previous and improved that. Whereas the previous system is based on GloSea5GA3, the improved one is built on GloSea5GC2. GloSea5GC2 is a fully coupled global climate model with an atmosphere, ocean, sea-ice and land components through the coupler OASIS. This is comprised of component configurations Global Atmosphere 6.0 (GA6.0), Global Land 6.0 (GL6.0), Global Ocean 5.0 (GO5.0) and Global Sea Ice 6.0 (GSI6.0). The compositions have improved sea-ice parameters over the previous model. The model resolution is N216L85 (~60 km in mid-latitudes) in the atmosphere and ORCA0.25L75 ($0.25^{\circ}$ on a tri-polar grid) in the ocean. In this research, the predictability of each system is evaluated using by RMSE, Correlation and MSSS, and the variables are 500 hPa geopotential height (h500), 850 hPa temperature (t850) and Sea surface temperature (SST). A predictive performance shows that GloSea5GC2 is better than GloSea5GA3. For example, the RMSE of h500 of 1-month forecast is decreased from 23.89 gpm to 22.21 gpm in East Asia. For Nino3.4 area of SST, the improvements to GloSeaGC2 result in a decrease in RMSE, which become apparent over time. It can be concluded that GloSea5GC2 has a great performance for seasonal prediction.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.3
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• pp.232-240
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• 2019

Approximately 80% of the world's sea cucumbers Apostichopus japonicas are processed into dried sea cucumbers. The hot air-drying method is currently used in industry, but it has many problems, such as a short drying time, severe browning, high nutrition loss, and low recovery. In this study, the moisture absorption rate, dry recovery rate, and lipid nutrient composition of sea cucumber dried by heat pump decompression and with a hybrid dryer were investigated. The moisture absorption rates for hybrid-dried sea cucumbers at 24, 48, 72, 96, and 120 h were 241.3%, 427.7%, 652.0%, 721.0%, and 742.2%, respectively. The moisture absorption rates for hot air-dried sea cucumbers were 155.8%, 240.0%, 390.3%, 655.5%, and 667.4%, respectively. Thus, moisture absorption was faster and greater with hybrid drying than with hot air drying. The dry recovery rate at 24 h was greater for hybrid-dried sea cucumber (70.7%) than for hot air-dried sea cucumber (59.8%). Saturated fatty acid contents of the hybrid- and hot air-dried sea cucumbers were 30.0% and 37.5%, respectively. Moreover, greater ${\Sigma}n-3$ polyunsaturated fatty acid content was found in hybrid-dried sea cucumber (15.8%) than in hot air-dried sea cucumber (11.7%).

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.58 no.4
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• pp.289-298
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• 2022

Sea anchor for fishery is commonly used in jigging fishery and purse seine. The study of sea anchor was studied for improvement of opening efficiency and drag by changing the type of shape and the diameter of vent. However, standard specification of sea anchor is not set and has not been studied for underwater stability. Therefore, this study aimed to improve underwater stability of sea anchor by changing a vent diameter and weight of sinker. The experiment was conducted in flume water tank. The experiment model of sea anchor was made from actual model of sea anchor which is used in fishery by similarity law. The model of sea anchor was designed to different types of vent diameter and weight of sinker in different current speed. The value of movement of side to side (X-axis), drag of sea anchor (Y-axis) and movement of up and down (Z-axis) was measured for 30 seconds. Each value of X, Y, Z-axis was analyzed through t-test and ANOVA analysis to verify that each value had a significant difference according to the difference compositions. There was correlation between the movement of X-axis and Z-axis. The drag of sea anchor was stronger as the current speed increased. However, the larger the vent diameter, the weaker the drag. From the result of the standard deviation, the movement of X-axis was inversely proportional to the vent diameter. However, movement of Z-axis was larger as the weight of sinker was the heaviest or lightest from the result of the standard deviation. These results suggest that the sea anchor should be combined with proper size of the vent diameter and the weight of sinker to improve the stability.

• Atmosphere
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• v.34 no.2
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• pp.97-106
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• 2024

The seasonal forecast skill of tropical cyclones (TCs) in the Northern Hemisphere from the Korea Meteorological Administration (KMA) Global Seasonal Forecast System version 6 (GloSea6) hindcast has been verified for the period 1993 to 2016. The operational climate prediction system at KMA was upgraded from GloSea5 to GloSea6 in 2022, therefore further validation was warranted for the seasonal predictability and variability of this new system for TC forecasts. In this study, we examine the frequency, track density, duration, and strength of TCs in the North Indian Ocean, the western North Pacific, the eastern North Pacific, and the North Atlantic against the best track data. This methodology follows a previous study covering the period 1996 to 2009 published in 2020. GloSea6 indicates a higher frequency of TC generation compared to observations in the western North Pacific and the eastern North Pacific, suggesting the possibility of more TC generation than GloSea5. Additionally, GloSea6 exhibits better interannual variability of TC frequency, which shows relatively good correlation with observations in the North Atlantic and the western North Pacific. Regarding TC intensity, GloSea6 still underestimates the minimum surface pressures and maximum wind speeds from TCs, as is common among most climate models due to lower horizontal resolutions. However, GloSea6 is likely capable of simulating slightly stronger TCs than GloSea5, partly attributed to more frequent 6-hourly outputs compared to the previous daily outputs.

• 한국해양학회지
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• v.29 no.3
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• pp.228-238
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• 1994

The change of sea-level is a good indicator of the change of climate during the Quaternary period. The sea-levels in the world have been changing very irregularly during that time. The pattern of the Quaternary sea-level change was assumed to be a stochastic fractal in this study. We measured fractal dimensions of the Holocene sea-levels of the Hudson river estuary and the Delaware coast. A box counting method gave almost the same values. i.e., D=1.358 for the Hudson sea-level changes and D+1.346 for the Delaware sea-level changes. the ability of the inverse method of fractal interposea-levels. IFIF reproduction the realistic sea-levels for the both of them. The delaware sea-level data made less statistical errors for the interpolation of IFIF than the Hudson and the Delaware sea-levels. IFIF reproduction the realistic sea-levels for the both of them. The Delaware sea-level data made less statistical errors for the interpolation of IFIF than the Hudson sea-level data. This suggests that the Delaware sea-level data are more reliable than the Hudson sea-level data was calculated from the fractal dimension of the Delaware sea-level data. Fractal interpolation functions (FIF) was used to reconstruct the peleosea-levels of the Korean coasts and the Atlantic Ocean coasts of the United States. The Korean Peleosea-level change generacted by FIF is different from the peleosea-level change of the eastern U.S.. The Korean peleosea-levels are much higher than the eastern U.S. Paleosea-levels, comparing to each other from the present to 8,000 BP.

• Journal of Life Science
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• v.7 no.1
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• pp.17-23
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• 1997

This study was designed as a part of efforts to investigate the biochemical pollutant markers for diagnosis of maine pollutions by changes in cholinesterase activity of the flounder (Paralichthys olivaceus)in Yellow Sea of Korea. Acetylcholinesterase (AChE) activities in brain and muscle of cultured flounders in Yellow Sea were remarkably lower (40-50% and 40-55%, respectively)than those of wild flounder in Pohang (control) of East Sea, but AChE activities in brain and muscle of wild flounders in Yellow Sea were significantly lower(15-40% and 25-35%, respectively)than those of wild flounder in Pohang of East Sea. Butyrylcholinesterase(BChE) activities in barin and muscle of cultured flounders in Yellow Sea were remarkably lower(70-75% and 65-75%, respectively) than those of wild flounder in Pohang of East Sea, but BChE activities in barin and muscle of wild flounders in Yellow Sea were significantly lower (15-40%and 25-35%, respectively)than those of wild flounder in Pohang of East Sea. Lactate dehydrogenase (LDH) activities in serum of cultured flounders in Yellow Sea were significantly 10-50% higher than those of wild flounder in Pohang of East Sea, but LDH activities in serum of wild flounders in Yellow Sea were significantly 20-25% higher than those of wild flounder in Pohang of East Sea. It suggests that AChE and BChE activities in brain and muscle of cultured and wild flounders of Yellow Sea may be used as the most effective mean in a biochemical markers for diagnosis of pollutant effects by organophosphorus pesticides.