• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.6
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• pp.1089-1098
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• 2020

In this study, we propose a method to detect red tide Cochlodinium Polykrikoide using by machine learning and geostationary marine satellite images. To learn the machine learning model, GOCI Level 2 data were used, and the red tide location data of the National Fisheries Research and Development Institute was used. The machine learning model used logistic regression model, decision tree model, and random forest model. As a result of the performance evaluation, compared to the traditional GOCI image-based red tide detection algorithm without machine learning (Son et al., 2012) (75%), it was confirmed that the accuracy was improved by about 13~22%p (88~98%). In addition, as a result of comparing and analyzing the detection performance between machine learning models, the random forest model (98%) showed the highest detection accuracy.It is believed that this machine learning-based red tide detection algorithm can be used to detect red tide early in the future and track and monitor its movement and spread.

• Journal of the Korean earth science society
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• v.39 no.2
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• pp.119-130
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• 2018

Aerosol Optical Properties (AOPs) are retrieved using the geostationary satellite instruments such as Geostationary Ocean Color Imager (GOCI), Meteorological Imager (MI), and Advanced Himawari Imager (AHI) through Yonsei AErosol Retrieval algorithm (YAER). In this study, the retrieved aerosol optical depths (AOD)s from each instrument were intercompared and validated with the ground-based sunphotometer AErosol Robotic NETwork (AERONET) data. As a result, the four AOD products derived from different instruments showed consistent results over land and ocean. However, AODs from MI and GOCI tend to be overestimated due to cloud contamination. According to the comparison results with AERONET, the percentage within expected errors (EE) are 36.3, 48.4, 56.6, and 68.2% for MI, GOCI, AHI-minimum reflectivity method (MRM), and AHI-estimated surface reflectance from shortwave Infrared (ESR) product, respectively. Since MI AOD is retrieved from a single visible channel, and adopts only one aerosol type by season, EE is relatively lower than other products. On the other hand, the AHI ESR is more accurate than the minimum reflectance method as used by GOCI, MI, and AHI MRM method in May and June when the vegetation is relatively abundant. These results are explained by the RMSE and the EE for each AERONET site. The ESR method result show to be better than the other satellite product in terms of EE for 15 out of 22 sites used for validation, and they are better than the other product for 13 sites in terms of RMSE. In addition, the error in observation time in each product is found by using characteristics of geostationary satellites. The absolute median biases at 00 to 06 Universal Time Coordinated (UTC) are 0.05, 0.09, 0.18, 0.18, 0.14, 0.09, and 0.10. The absolute median bias by observation time has appeared in MI and the only 00 UTC appeared in GOCI.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.1
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• pp.13-24
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• 2022

The Arctic Ocean is very sensitive to global warming and Arctic Ocean sediments provide a records of terrestrial climate change, analyzing their composition helps clarify global warming. The gravity core sediment ARA07C-St02B was collected at the East Siberian margin during an Arctic expedition in 2016 on the Korean ice-breaking vessel ARAON, and its provenance was estimated through sedimentological, mineralogical and geochemical analysis. The core sediment was divided into four units based on sediment color, sand content and ice-rafted debris content. Units 1 and 3 had higher sand and ice-rafted debris contents than units 2 and 4, and contained a brown layer, whereas units 2 and 4 were mainly composed of a gray layer. Correlation analysis using the adjacent core sediment ARA03B-27 suggested that the sediment units were deposited during marine isotope stage 1 to 4. The bulk mineral, clay mineral, and geochemical compositions of units including a brown layer differed from units including a gray layer. Bulk and clay mineral compositions indicated that coarse and fine sediments had a different origin. Coarse sediments might have been deposited mostly by the East Siberian Coastal Current from the Laptev Sea and the East Siberian Sea or by the Beaufort Gyre from the Chukchi Sea, whereas fine sediments might have been transpoted mostly by currents from the East Siberian Sea, the Chukchi Sea and the Beaufort Sea. Some of the coarse sediments in unit 1 and fine sediments in unit 3 might have been deposited by iceberg ice, sea ice or current from the Beaufort Sea and the Canada Archipelago. Investigating the geochemical composition of the potential origins will elucidate the origin and transportation of the study area's core sediments.

• Korean Journal of Remote Sensing
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• v.38 no.5_1
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• pp.609-625
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• 2022

Validation of satellite data products is critical for subsequent analysis that is based on the data. Particularly, performance of ocean color products in turbid and shallow near-land ocean areas has been questioned for long time for its difficulty that stems from the complex optical environment with varying distribution of water constituents. Furthermore, validation with ship-based or station-based measurements has also exhibited clear limitation in its spatial scale that is not compatible with that of satellite data. This study firstly performed validation of major GOCI-II products such as remote sensing reflectance, chlorophyll-a concentration, suspended particulate matter, and colored dissolved organic matter, using the in-situ measurements collected from ship-based field campaign. Secondly, this study also presents preliminary analysis on the use of drone images for product validation. Multispectral images were acquired from a MicaSense RedEdge camera onboard a UAV to compensate for the significant scale difference between the ship-based measurements and the satellite data. Variation of water radiance in terms of camera altitude was analyzed for future application of drone images for validation. Validation conducted with a limited number of samples showed that GOCI-II remote sensing reflectance at 555 nm is overestimated more than 30%, and chlorophyll-a and colored dissolved organic matter products exhibited little correlation with in-situ measurements. Suspended particulate matter showed moderate correlation with in-situ measurements (R²~0.6), with approximately 20% uncertainty.

• Journal of the Korean Society of Costume
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• v.20
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• pp.31-47
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• 1993

1. The relationship between Korea and Buk-Song had maintained for 164 years(964 1126 A.D). The period of relationship was from KwangJong Year 13(4years after establishing Buk-Song), Song Tae-Cho 1 year, to HeumJong Cheong Dang 1st year(InJong 4years in Koran). Author divides into three periodic terms, and remarkable diplomatic facts are as follows. 1) KwangJong year 13(963 A.D) SungJong year 13(994 A.D) : Normal relations, Song needed Korea's armed support. 2) MokJong year 6(1003 A.D) HyunJong year 9(1018 A.D) : Not steady relations and broke up, by MunJong year 26, Dang requested to resume the diplomatic relations. 3) MunJong year 25(1017 A.D) InJong 4(1126 A.D) : Song utilized Korea as a back supporter, but Song destructed by Keum. 2. Korea was donated knightage without offcial clothing by BukSong 10 times(KwangJong year 13 SungJong year 11). However during 164 years. Song presented some clothings Korea friendly. 3. Even though Korea cound not continue the steady diplomatic relations, Korea had been influenced the social systems including cloth-ing systems by Dang. Song dynasty. 4. The author studys historical materials which show that TongilSh-Shinra adapted social systems of Dang dynasty including clothing systems, which was succeeded to Korea for 200 years. Details are as follows ; 1) Original clothing color-systems which were Ja(purpil), Cheong(blue), Hwang(yellow), Pi, called 4-clored-system, of Tongil-Shinra, was suceeded to Korea, Above mentioned clothing systems of three countries of Korean peninsula. 2) When Korea unified the certificate of Pisam holders were superior from those of Tongil-Shinra and Hoo-Bakjae. There two classes used same seried-color 'ja, (Dan, Pi), Cheong(blue), Hwang(yellow)', or 'ja, (Dan, Pi), Cheong' and lasted to KwangJong year10 as a of-ficial clothing. 3) KwangJong year 7, according to the three colored official clothing system of Hooju, accepted Hooju's KwangJong year 11, that shifted 'Ja, (Dan, Pi), Cheong, Hwang', or, Ja, (Dan, Pi) Cheong', to 'Ja, Dan, Pi, Rok(green)'. 4) The clothing systems which are ja, (Dan, Pi), Rok which established KwangJong year 11 shifted to Song's, Ja, Ju(orange), Rok, Cheong, which had happened SungJong year 14 to MokJong 1st year. 5) 4-colored systems ('Ja, Pi, Rok, Cheong (distictable : sky blue, ocean blue)' shifted to 3 colored system which established Song ShingJong 1st year, which succeeded to Nam-Song and Keum. 5. The relationship between Korea and Yo had maintained for 207 years(918 1125 A.D). The period of relationship was from TaeJo 1st year to InJong year 3. 6. Yo, and Korea were called for king(15 times), prince(7 times). 7. Korea was donated knightage by Yo. The time when HyunJong year 13, Yo donated official clothing. From that time had used to do. The author divides into three periodic terms and discrives the shifting the formal clothing systems. Details were as follows ; 1) HyunJong year 13 MunJong year 8 : Even donating clothing systems from Yo had maintained for 35 years, Yeo, Song, Yo, three countries had not have formal cloth-ing, because they had been on the strug-gling. So that Korea had followed the same way of informal clothing. 2) MunJong year 918 : Yo donated the formal clothing to Korea for the King. Diplomatic condition was in the control, so that whole three countries used formal clothing. 3) MunJong year 19 YeaJong year 3 : Korea was donated 'Kuryumyun Kujangbokje', which became the formal clothings vs China.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.4
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• pp.316-324
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• 1985

Vacuum-packed and seasoned smoked-dried products of red squid, Ommastrephes bartrami, caught in the Northern Pacific Ocean, were prepared and stored at room temperature for 90 days to test their keeping quality. Defrosted squids were eviscerated, skinned, and cut. The mantle meats were flavored with seasoning powders prepared from sugar, sorbitol, salt, monosodium glutamate, or smoke flavor (Smoke-EZ, Alpha Foods Co., Ltd.). After seasoning, the mantle meats were dried at $45^{\circ}C$ for 7 hours, vacuum packed in plastic film bags, and pasteurized in water at $95^{\circ}C$ for 30 minutes. Three kinds of products were prepared : control products (seasoned-dried), solid smoked seasoned-dried and liquid smoked seasoned-dried. The moisture level, water activity, color value (L, a and b value), texture, and viable cell counts of bacteria in these products were determined during storage at room temperature, $5^{\circ}C\;and\;35^{\circ}C$, respectively. The results showed that the products could be preserved at good condition for 90 days though they developed pale brown color during storage. The contents of free amino acids, nucleotides and their related compounds, and the compositions of fatty acids of raw squid and smoked products were analysed. In the amino acids, arginine, taurine, glycine and proline were abundant in raw and smoked products. The contents of hypoxanthine of raw and smoked products were higher than the other nucleotides and their related compounds. In fatty acid compositions of raw and smoked products, the dominant fatty acids were docosahexaenoic acid (22:6), hexadecanoic acid(16:0) and eicosapentaenoic acid (22:5).

• Korean Journal of Ichthyology
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• v.13 no.2
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• pp.117-122
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• 2001

Three species, Gymnogobius urotaenia, G. sp. 1 and G. sp. 2, collected at Hosan-river, Hosan-ri, Samcheock-si, Gangwon-do, Korea, were examined for the study of sexual dimorphism. The three species have peculiar nuptial pigmentation during the breeding season: all females of the three species showed an intense black coloration on the ventral part of the head, the pelvic fin, the anal fin and the margin of the first dorsal fin. There was a difference between G. sp. 1 and the other two species in 1/3 from margin of first dorsal fin. Namely, G. sp. 1 showed an intense black coloration, whereas the other two species had an intense yellow coloration. All females of the three species showed the same, intensely yellow coloration in the ventral part of the body. Males of G. urotaenia and G. sp. 2 had almost the same nuptial pigmentation, however the former showed diffuse black coloration in the anal fin, whereas the latter had an intensely black anal fin. Males of G. sp. 1 differed from those of the other two species in their yellow color on the ventral part of the head, the pelvic f ins, the anal fin, in contrast to the diffuse black coloration in those parts in the other species. The genital papilla of males was triangle-shaped, but that of females was heart-shaped. Significant differences between sexes include: G. urotaenia, 7 characters (body depth, head length, snout length, upper jaw length, head depth, pectoral fin ray length, eye diameter); G. sp. 1, 11 characters (body depth, head length, caudal peduncle length, caudal peduncle depth, snout length, upper jaw length, head width, head depth, anal fin ray length, pectoral fin ray length and caudal fin ray length); G. sp. 2, 10 characters (body depth, head length, caudal peduncle depth, snout length, upper jaw length, head width, anal fin ray length, pectoral f in ray length, caudal fin ray length and eye diameter). Of the 5 characters which showed differences in all three species (body depth, head length, snout length, upper jaw length and pectoral fin ray length), females had higher values than males only in body depth, whereas males values in all other characters. The upper jaw length was the most distinctive sexually dimorphic feature, the upper jaw extended beyond the posterior margin of the eyes (p<0.001) in males but not in females.

• Journal of Life Science
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• v.20 no.2
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• pp.190-196
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• 2010

Nowadays many people use antibiotics to protect processed foods from many pathogenic bacteria. The abuse of antibiotics, however, can run the risk of creating resistant forms of bacterium. Our study focus is on making new substances that can not only replace antibiotics but also be friendly to the environment. In our experiments, we used fermented citrus fruit, soil microbes and coenzyme Q10 as probiotics and prebiotics. Chickens in the experimental group were fed these substances via oral route while those in the control group were not. After specific time periods, blood and feces samples were collected to test for Salmonella spp.. It is interesting that fermented citrus fruit was the most effective in suppressing this bacterium. Furthermore, dissection of the experiment group chickens shows that their livers did not change to a yellow color, in contrast to the control group. The results confirmed our proposal that the chickens fed with these materials can be protected from infection by Salmonella and other pathogens. These probiotics and prebiotics are highly practical because they are natural substances that can be easily recycled in the environment. It can also be used as an animal feed ingredient because of its safety.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.4
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• pp.417-423
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• 2002

The edible films were prepared from the protein of alaska pollack, Theragra chalcogrmma. Effects of plasticizer, cross linker and laminated film on physical properties such as tensile strength (TS), elongation (E) and water vapor permeability (WVP) of films were investigated. In adding various kinds of plasticizers, TS of the films prepared with propylene glycol (PG) was the highest, and followed sorbitol, polyethylene glycol 200 (PEG 200) and glycerol. Elongation of the films prepared with glycerol was the highest, then sorbitol, PEG 200 and PG. WVP of films showed lower in order of PG, sorbitol, glycerol and PEG 200.75 decreased with the increment of plasticizer concentration, but elongation increased, The addition of both PG and PEG 200 effected weakly on elongation, so they were inadequate as plasticizer for the film. Mixtures of glycerol and sorbitol, which showed opposing both TS and elongation in the films, could control the physical properties of the films. With increasing relative humidity, TS decreased, while elongation and equilibrium moisture content increased. By adding the cross linkers such as ascorbic acid, citric acid and succinic acid, TS and m of films increased, while elongation decreased. Ascorbic acid, citric acid, succinic acid were most effective for TS at 0.2, 0.1 and $0.1\%, respectively. Laminated film with alaska pollack protein and corn zein improved TS above two times, reduced WVP about $20\~30\%$, as compared with the Elm from alaska pollack protein. Two films did not show the difference to oxygen permeability, but they showed about tenfold greater oxygen resistance than polyethylene film. Laminated film showed higher b and $\Delta$E value of color difference, lower a and L value than the film from alaska pollack protein.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.1
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• pp.97-106
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• 1984

The Antarctic krill, Euphausia superba, is drawing attention over the world as the largest source of unutilized proteins in the ocean. For the use of krill as a human food, processing conditions of krill sauce by autolysis and/or commercial proteolytic enzyme digestion were examined. The krill was chopped and mixed with equal weight of water, and hydrolyzed by autolysis and/or commercial proteolytic enzyme digestion. The optimal conditions for hydrolysis of krill were $52.5^{\circ}C$, pH 7.0-7.5, 3 hours by autolysis, $52.5^{\circ}C$, pH 6.3, 3hours by bromelain (0.5 %) digestion, and $52.5^{\circ}C$, pH 7.0-7.5, 3 hours by commercial complex enzyme (5 %) digestion, respectively The maximum hydrolyzing rate of protein were 83.2 % by autolysis, 89.7 % by bromelain digestion, 92.7 % by commercial complex enzyme digestion. After krill meat hydrolyzed by autolysis at optimum condition, inactivated at $100^{\circ}C$ for 20 minutes and filtered with Buchner funnel. Two kinds of products were prepared with krill hydrolysate and preservatives: one contained 10 % of sodium chloride and 0.06 % of benzoic acid and the other 10 % of sodium chloride and 3 % of ethyl alcohol. These products were filled in the sterilized glass bottle and sealed. The pH, volatile basic nitrogen, amino nitrogen, color value (L, a and b values) and viable counts of bacteria were determined during storage at $37^{\circ}C$. The results showed that the products could be preserved in good condition during one month at $37^{\circ}C$. As a method to reduce the sodium level in krill sauce, it is convinced that sodium chloride could be replaced half in partially by potassium chloride. In the products prepared from krill by autolysis, bromelain or commercial complex enzyme digestion, hypoxanthine and 5'-IMP were abundant among the nucleotides and their related compounds as 15.3-20.4 ${\mu}mole/g$, dry solid, 2.2-2.5 ${\mu}mole/g$, dry solid, respectively. The abundant free amino acids were lysine, leucine, proline, alanine and valine. The contents of these amino acids were 67.4 %, 69.4 %, 69.8 % of the total free amino acids of each products. And TMAO, betaine and total creatinine were low in contents. The flavor of krill sauce prepared from krill by autolysis or enzyme digestion was not inferior to that of traditional Kerean soy sauce by sensory evaluation.