• The Korean Journal of Malacology
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• v.20 no.1
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• pp.27-34
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• 2004

Based on both field and laboratory experiments, seasonal changes in the species composition and abundance of phytoplankton in the gut contents of the jedo venus clam, Protothaca jedoensis, and its feeding selectivity were investigated. The phytoplankton in the gut contents comprised Bacillariophyceae (diatom), Chlorophyceae, Chrysophyceae, and Dinophyceae, of which the diatoms being the most predominant throughout the year. Although the number of species and the abundance of phytoplankton in the sea water were always more diverse and more abundant than in the gut contents, the relative number and abundance were generally similar in the seawater and in the gut contents. In the laboratory experiments, the relative abundances of Coscinodiscus marginatus and Thalassirosira eccentrica were much more higher in the gut contents than any other algal species, while Paralia sulcata, Skeletonema costatum, and Eucampia zodiacus were abundant in order of cell density in the ambient water. These results suggest that P. jedoensis may feed preferably on single algal cell or smaller chains of algal cells.

• Ocean and Polar Research
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• v.26 no.2
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• pp.199-205
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• 2004

$SiO_2$ and CaO are added to decrease the smelting temperature in the reduction-smelting method for manganese nodule processing. These elements are components of the manganese nodules and might be very important controlling factors in the processing due to the locally variable content. The 707 chemical data of manganese nodules acquired from 1994 to 2001 in KODOS(Korea Deep Ocean Survey) area were used for the hierarchical cluster analysis. The chemical data were classified by the morphological types, and the averages of the chemical data for each station were classified by the facies groups and the localities. All data are plotted on the $SiO_2-CaO-MnO$ phase diagram at $1773^{\circ}K$ to compare with the best compositional area in the nodule smelting. Variations and distributions of $SiO_2$ and CaO in KODOS nodules were also reviewed. The mineral phases assigned by the cluster analysis are CFA(Carbonate Fluorapatite), Fe-oxide, Al-silicate, and Mn-oxide. MnO contents are generally higher than $SiO_2$ contents in most of the morphological types except for the Is- and It-type. The Dt- and Tt-type show wider range and the E-types show high anomaly in their CaO contents. The stations which belong to facies group A and B show generally higher MnO contents than $SiO_2$ contents, however, the stations of facies group C and D show wide range in their MnO and $SiO_2$ contents. It seems to be very important to control the $SiO_2$ contents in the processing because of the wide range in the northern area. The additions of approximately 10 wt.% CaO and 10 wt.% $SiO_2$ are recommended for the northern area, whereas, the additions of approximately 10 wt.% CaO and 20 wt.% $SiO_2$ are recommended for the southern area.

• Fisheries and Aquatic Sciences
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• v.23 no.3
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• pp.9.1-9.6
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• 2020

Background: Fucosterol is a compound commonly found in algae that has various biological activities. The purpose of this study was to develop a high-performance liquid chromatography (HPLC) validation method for fucosterol and to compare the fucosterol contents of 11 algal species from Ulleungdo, Korea. Method: In this study, we successfully isolated and identified fucosterol from a 70% EtOH extract of Sargassum miyabei, and subsequently conducted specificity, linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy, and precision analyses for development of an HPLC validation method. Fucosterol contents were compared using the established HPLC validation conditions. Results: We successfully isolated fucosterol from a 70% EtOH extract of S. miyabei and identified it based on spectroscopic analysis. On the basis of HPLC validation using the fucosterol isolated from S. miyabei, we confirmed specificity (8.5 min), linearity (R² = 0.9998), LOD (3.20 ㎍ mL^-1), LOQ (9.77 ㎍ mL^-1), accuracy (intra-day and inter-day variation, 90-110%), and precision (RSD, 1.07%). Fucosterol contents in the 11 assessed algal species ranged from 0.22 to 81.67 mg g^-1, with the highest content being recorded in a 70% EtOH extract of Desmarestia tabacoides (81.67 mg g^-1), followed by that of Agarum clathratum (78.70 mg g^-1). Conclusions: The results indicate that 70% EtOH extracts of D. tabacoides and A. clathratum containing fucosterol with various effects can be potential alternative sources of fucosterol.

• Food Science and Biotechnology
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• v.16 no.3
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• pp.367-373
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• 2007

Livers of skipjack tuna (Katsuwonus pelamis) and yellowfin tuna (Thunnus albacares) were investigated on the food compositional characteristics and also compared to that of Alaska pollack (Theragra chalcogramma). The proximate compositions of skipjack tuna and yellowfin tuna livers were high in crude protein, carbohydrate, and crude ash, while were low in crude lipid when compared to that of Alaska pollack liver. The results of heavy metal suggested that tuna livers appeared safe as a food resource. The total amino acid contents of skipjack tuna and yellowfin tuna livers were 17.7 and 17.1 g/100 g, respectively, and the major amino acids in both livers were aspartic acid, glutamic acid, alanine, valine, leucine, and lysine. Tuna livers were good sources of iron and zinc, while have low lipid content. The extractive nitrogen contents of skipjack tuna and yellowfin tuna livers were 526.5 and 468.2 mg/100 g, respectively, and their major free amino acids were taurine, glutamic acid, and alanine. From the results of taste value, the major taste active compounds among free amino acids were glutamic acid and aspartic acid.

• Journal of the Korean Association of Geographic Information Studies
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• v.22 no.4
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• pp.146-157
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• 2019

This study, as a pilot study to implement and extend the marine healing which has been rapidly extending oversea areas into the domestic market, has collected seven major marine healing resources such as ocean water, sand, salt, mud, seaweeds, forest, and weather targeting selected four pilot municipalities and established a GIS DB. Furthermore, web GIS based marine healing portal has been established to support the easier utilization of the GIS DB and various marine healing related contents, thereby facilitating expansion of related industry. The portal includes marine thematic maps as well as research papers, related therapy manuals, and various activities and programs of the pilot municipalities. It is expected that the portal would contribute to the expansion of the domestic marine healing industry significantly through the pilot operation of the portal, not to mention of the needs of subsequent studies for expansion of the marine GIS DB and securing more various contents.

• Journal of Advanced Navigation Technology
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• v.13 no.1
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• pp.11-18
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• 2009

As a marine leisure industry has being developed and demands for leisure culture have rapidly increased, the needs for services offering marine safety and related information are growing. Accordingly, in the study I developed the contents providing server to support this with ENC agent who presents geographical information of digitalized Electronic Nautical Chart satisfying with the standard(S-57) by International Hydrographic Organization and a web searching agent who builds a database by collecting marine-related information in order to provide a variety of realtime information such as weather, fishing and news. In addition, I designed and embodied network based mobile contents which can be presented on a WIPI(Wireless Internet Platform for Interoperability) based portable handset by receiving an ENC and other processed information from server. With the results produced by such experiments, I measured a compressibility corresponding to a image compression format of electronic nautical chart transmitted and analyzed the correlation between increase in packets of requested information and the cost.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.3
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• pp.221-229
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• 2018

Various types of dried laver Pyropia yezoensis have been produced in response to increasing demand and other laver goods manufactured using different processing methods are continuously being developed. The dried laver used in this experiment was initially heated at $165^{\circ}C$ for 3 seconds, followed by second heating at a high temperature ($340-350^{\circ}C$) to increase the storage period and enhance taste and flavor. Nutrient analysis of each sample heated under three conditions revealed that the protein and lipid contents were highest in samples from D company, while the carbohydrate contents remained relatively stable. After storage for 10 weeks at room temperature, changes in the composition were evaluated. The results showed decrease in protein (30%-49%) and essential amino acid contents. During storage, the major unsaturated fatty acids contained in dried laver slightly changed to 53.4%-56.0% in the form of EPA, while saturated fatty acids slightly increased to 18.4%-22.6% in the form of palmitic acid. The variables derived from fatty acid composition, such as atherogenic and thrombogenic, and hypocholesterolemic/hypercholesterolemic dietary indices, and polyunsaturated fatty acids/saturated fatty acids ratio, also indicated reasonable levels of stability. However, the laver should be consumed within 2 months.

• Journal of the Korean Society of Marine Environment & Safety
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• v.7 no.2
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• pp.105-121
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• 2001

After the Sea Prince oil spill accident in 1995, the korean government has taken a measure to establish an emergency response system and equip clean-up capacity against large spill, major contents of which are as follows: First, Korea Marine Pollution Response Corporation has been established as a non-government organization for recovery of spilled oil in order to improve private response capabilities. Second, clean-up equipments, such as large clean-up vessels and oil fences for the open sea operation has been expanded. Third, a national contingency plan on the large spill accidents has been established compliance with the provisions of Article 6 of the OPRC 1990. However, there exist some problems in the national response system, such as clearly roles definition between government and private agencies; propel amendment of the Marine Pollution Prevention Act to incorporate major contents of the OPRC 1990; and training and exercises of clean-up personnel. With the above problems in mind, this paper reviews the current issues on the national oil pollution response system and recommends policy-making to tackle to those problems.

• Journal of Fisheries and Marine Sciences Education
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• v.17 no.1
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• pp.67-75
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• 2005

Mobile devices compared with personal computers on the desktop have low bandwidths, small screens, and relatively slow speeds. These systems have practical problems with information searches in a web environment. Information searching of various web contents on the small size screen has especially severe limitations. We propose a filtering technique of web contents which can overcome the limitations of small size screens and meet the user requirements in a PDA environment. For these constructions, we first divide the screen into segment blocks and then extract content blocks according to the user requirements, so that only filtered web contents will be shown. The performance evaluation of the proposed technique saves an average time of about 30% by displaying only the extracted information instead of the whole web page.

• Journal of Marine Bioscience and Biotechnology
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• v.12 no.1
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• pp.40-49
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• 2020

This article emphasized the physiological characteristics of the selected marine microalgal strains obtained from the culture collection of the National Marine Biodiversity Institute of Korea (MABIK). Therefore, in this study, 13 different marine microalgal strains belonging to the phylum Chlorophyta were analyzed for the composition of fatty acids, elements, photosynthetic pigments, and monosaccharides, as well as the lipid and protein contents. The results presented that the primary fatty acids were palmitic (C_16:0), palmitoleic (C_16:1 n-7), stearic (C_18:0), oleic (C_18:1 n-9), linoleic (C_18:2 n-6), and α-linolenic (ALA, C_18:3 n-3) acid in the evaluated microalgae. The lipid contents of heterotrophically grown strains ranged from 15.1% to 20.4%. The calorific values of the strains were between 17.4 MJ kg^-1 and 21.3 MJ kg^-1. The major monosaccharides were galactose, glucose, and mannose, while the primary photosynthetic pigments were chlorophyll-a (Chla), chlorophyll-b (Chlb), and lutein, respectively. Based on the results, the microalgal strains showed high potentials in the use of microalgae-based technologies to produce biochemicals, food, and renewable fuels as they are rich in sustainable sources of high-value bio-compounds, such as antioxidants, carbohydrates, and fatty acids.