• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.18 no.1
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• pp.40-46
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• 2013

The isotope ratios of $^{13}C/^{12}C$ and $^{18}O/^{16}O$ for a sample in a mass spectrometer are measured relative to those of a pure $CO_2$ reference gas (i.e., laboratory working standard). Thus, the calibration of a laboratory working standard gas to the international isotope scales (Pee Dee Belemnite (PDB) for ${\delta}^{13}C$ and Vienna Standard Mean Ocean Water (V-SMOW) for ${\delta}^{18}O$) is essential for comparisons between data sets obtained by other groups on other mass spectrometers. However, one often finds difficulties in getting well-calibrated standard gases, because of their production time and high price. Additional difficulty is that fractionation processes can occur inside the gas cylinder most likely due to pressure drop in long-term use. Therefore, studies on laboratory production of pure $CO_2$ isotope standard gas from stable solid calcium carbonate standard materials, have been performed. For this study, we propose a method to extract pure $CO_2$ gas without isotope fractionation from a solid calcium carbonate material. The method is similar to that suggested by Coplen et al., (1983), but is better optimized particularly to make a large amount of pure $CO_2$ gas from calcium carbonate material. The $CaCO_3$ releases $CO_2$ in reaction with 100% pure phosphoric acid at $25^{\circ}C$ in a custom designed, evacuated reaction vessel. Here we introduce optimal procedure, reaction conditions, and samples/reactants size for calcium carbonate-phosphoric acid reaction and also provide the details for extracting, purifying and collecting $CO_2$ gas out of the reaction vessel. The measurements for ${\delta}^{18}O$ and ${\delta}^{13}C$ of $CO_2$ were performed at Seoul National University using a stable isotope ratio mass spectrometer (VG Isotech, SIRA Series II) operated in dual-inlet mode. The entire analysis precisions for ${\delta}^{18}O$ and ${\delta}^{13}C$ were evaluated based on the standard deviations of multiple measurements on 15 separate samples of purified $CO_2$. The pure $CO_2$ samples were taken from 100-mg aliquots of a solid calcium carbonate (Solenhofen-ori $CaCO_3$) during 8-day experimental period. The multiple measurements yielded the $1{\sigma}$ precisions of ${\pm}0.01$‰ for ${\delta}^{13}C$ and ${\pm}0.05$‰ for ${\delta}^{18}O$, comparable to the internal instrumental precisions of SIRA. Therefore, we conclude the method proposed in this study can serve as a way to produce an accurate secondary and/or laboratory $CO_2$ standard gas. We hope this study helps resolve difficulties in placing a laboratory working standard onto the international isotope scales and does make accurate comparisons with other data sets from other groups.

• Journal of Korea Entertainment Industry Association
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• v.14 no.4
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• pp.289-303
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• 2020

The purpose of this study is to provide adequate datas on number of people who are in golf related field and also further expend that number for golf industry. The main stream of this study is to map out present golf related jobs and how this study can help golf industry in general. To make a greater improvements on golf industry with more job opportunity following ideas were presented. First, improving education on "hand on experiences on the field of golf industry" Better educating potential employees for golf industry for the right positions can enhance overall work environment. To do so, the society and the schools must come to agreement to provide adequate curriculum for people. Second, implementing "a golf club division program." The support from Ministry of Culture and Sports and Tourism Department, which are govern by Republic of Korea, are aggressively working to expend the golf business and also recruit elite personnel like former tour players to work on the field to better operate the whole system. Third, performing a thorough research on current golf related jobs and numbers and diversity on the field. Fourth, developing a specific and a differentiated golf job fields for better future for people and students who majored in golf industry. So that they cam feel secured and have a sense of dignity. Finally, strengthening the golf industry's competitiveness. The golf related companies have to step up to higher gear. With working in harmony between golf industry and government can assure of brighter future for our next generation.

• Journal of Fisheries and Marine Sciences Education
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• v.3 no.2
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• pp.47-72
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• 1991

To obtain the principal data for useful treatment and processing of Korean geoduck (Panope japonica A. ADAMS) which inhabit mostly at Dong-Hae coastal area in Korea, changes of $NH_2$-N, TMAO, TMA, total creatinine, protein composition and fatty acid composition in raw and blanched geoduck muscle during storage at $-20^{\circ}C$ were investigated. In addition, its chemical composition variation in the whole year was elucidated. The moisture content in geoduck muscle meat was 78.1% to 82% in the whole year. Particularly, in July its moisture content was maximum as 82% and in September minimum as 78.1%. Crude protein was in the range of 12.3-16.4%, crude lipid the average was 1.5%, crude ash on the average was 1.4%. The abundant fatty acids in geoduck muscle oil were $C_{16}$ : 0, $C_{16}$ : 1, $C_{18}$ : 0, $C_{18}$ : 1, $C_{20}$ : 5, and $C_{22}$ : 6 acids. During storage at $-20^{\circ}C$, content of unsaturated fatty acid such as eicosapentaenoic acid (EPA, $C_{20}$ : 5) and docosahexaenoic acid (DHA, $C_{22}$ : 6)in raw geoduck muscle decreased somewhat and the raw geoduck was slightly oxidized. Trimethylamine (TMA), volatile basic nitrogen (VBN)and $NH_2$-N of raw muscle increased compared to blanched muscle. Trimethylamine oxide (TMAO) was slightly decreased during the storage period. The muscle protein was approximately composed of 37% sarcoplasmic, 29% myofibrillar, 22% alkali soluble, and 12% stroma protein. Among several proteins, myofibrillar protein content decreased mostly, while the alkali-soluble and stroma protein content increased slightly during storage at $-20^{\circ}C$.

• Journal of Fisheries and Marine Sciences Education
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• v.4 no.1
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• pp.30-46
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• 1992

Korea's first exploratory tuna fishing was done with a used longliner in 1957. Then the commercial fishing has been made steady headway since the 1960's and grown up to one of major tuna fishing countries in 1970's. The tuna fishing aimed primarily at acquiring foreign currency, then tuna was exported directly from the overseas fishing base. Tuna, however, has been gradually favored by Koreans as high-proteined foods according to the growth of GNP since the 1970's. In 1980, the canned tuna began to be produced and sold at home. And so the demand of raw tuna for cannaries has steeply increased not only for home but also for abroad, and stimulated the development of tuna purse seine fishery. The author carried out a study on the development of tuna purse seine fishery in Korea and countries concerned-the United States and Japan-because it is recognized to be significant for the further development of this fishery. Just as purse seining was originated in the United States, so tuna purse seining was also pioneered by Californian fishermen in the west coastal waters of the United States (Eastern Pacific Ocean). They started to produce the canned tuna in the early 1900's, and the demand for raw tuna began to be increased rapidly. In those days, tuna was mostly caught by pole-and-line, but the catch amount was far away from the demand. To satisfy this demand, they began to try out fishing tuna by the use of purse seine which had been born in the eastern waters in the 1820's and applied to catch white fishes in the western waters of the United States in those days. Even though their trial was technically successful through severe trial and error, a new problem was raised on the management of tuna resource and the preservation of porpoise which was occassionally caught with tuna. Then the Inter-American Tropical Tuna Commission (IATTC) was established by countries neighboring to the United States in 1950 and they set up the Commission's Yellowfin Regulatory Area (CYRA) and regulated the annual quota for yellowfin. Then, American owners tried to send their seiners to the Western African waters to expand the fishing ground in 1967 and to the Centeral-Western Pacfic in 1974, and the fishing ground was widely expanded. The number of the United States' purse seiners amounted to about 150 in 1980, but the enthusiasm was gradually cooled thereafter and the number of seiner was decreased to 67 in 1986. The landing of tuna by purse seiners in the United States after 1980 maintains 200 thousands M/T or so with a little increase despite the decreasing of domestic seiners. This shows that the landing by foreign seiners are increasing, compared with the landing by domestic seiners are decreasing. In Japan, even though purse seining was introduced in 1880, they had fished tuna by longline and pole-and -line until the tuna purse seining was introduced from the United States again. In the 1960's, Japanese tuna seiners made the exploratory fishing in the South-western Pacific and West African waters with a limited success. In 1971, the government-funded research center "JARMRAC" conducted the exploratory fishing which extended to the Central American waters, the Asia-Pacific Region and the South-western Pacific. It had also much difficulties, till they improved the fishing gear adaptable to the new fishing condition in the South-western Pacific. Japanese government has begun to licence 32 single seiners and 7 group seiners since 1980 and their standard has lasted up to now. The catch in the Pacific Islands Region amounted to 160 thousands M/T in 1986. Korea's tuna purse seine fishery was originated in 1971 by Jedong Industrial Co., Ltd. with three used tuna purse seiners purchased from the United States, and they began to fish in the Eastern Pacific, but failed owing to the superannuation of vessel and the infancy of fishing technique. The second challenge was done by Dongwon Industrial Co., Ltd. in 1979, with one used seiner purchased from the United States, and started to fish in the Eastern Pacific. Even though the first trial was almost unsuccessful but they could obtain the noticeable success by removing the vessel to the South-western Pacific in 1980. This success stimulated the Korean entherprisers to take part in this fishery, and the number of Korean tuna purse seiners has been increased rapidly in accordance with the increased demand for raw tuna. The number of vessels actually at work amounted to 36 in 1990 and they operate in the South-western Pacific. The annual catch of tuna by purse seiners amounted to 170 thousands M/T in 1990 and ranked to one of the major tuna purse seining countries in the world.

• Korean Journal of Environment and Ecology
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• v.33 no.1
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• pp.1-8
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• 2019

Pintail (Anas acuta) is the major wintering bird in South Korea and known as a major mediator of the highly pathogenic avian influenza (HPAI). Pintail migrates long distances between Russian Siberia and Korea. This species prefers a rice paddy area as their winter habitat. The purpose of this study is to provide the data necessary for the conservation and management of bird habitats in Korea by understanding the wintering home-range and habitat of pintail in Korea. We captured six pintails using a cannon-net in the winter of 2015 and attached the GPS-mobile phone based telemetry (WT-300) on them to study the wintering home-range and wintering habitat. We analyzed the tracking location data using ArcGIS 9.0 Animal Movement Extension and calculated Kernel Density Estimation (KDE) and Minimum Convex Polygon (MCP). The average home-range in the wintering ground analyzed by MCP was $677.3km^2$ (SD=130.2, n=6) while the maximum and minimum were $847.7km^2$ and $467.5km^2$, respectively. Extents of home-range analyzed by KDE were $194.7km^2$ (KDE 90%), $77.4km^2$ (KDE 70%), and $35.3km^2$ (KDE 50%). The pintails mostly used both sea and paddy field as habitat in the winter season and utilized paddy fields more during the nighttime and than the daytime. We concluded that the home-range and habitat of pintails in the winter could be used as the reference data for the preservation of species, management of habitats, and coping with a breakout of HPAI.

• Journal of Life Science
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• v.32 no.4
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• pp.325-330
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• 2022

While swimming is a very popular competitive sports activity, swimming injuries are unique due to the repetitive nature of the swimming stroke and demanding training programs that can result in upper limb overuse. Therefore, the primary objective of this review was to analyze swimmers' injury areas, injury types by stroke type, and swimming rehabilitation, as well as to discuss safety management for improving swimming performance. In this study, the injuries incurred in swimming events were discussed in the order of upper limb injuries (neck, shoulder, arm, and wrist), lower limb injuries (knee and ankle), and waist injuries. An analysis by stroke type found that shoulder injuries occurred most often with freestyle, backstroke, and butterfly strokes, followed by rotator cuff injury, impingement syndrome, and SLAP (superior labral tear from anterior to posterior) lesions. Knee injuries were associated with the breaststroke, whereas spinal cord injuries occurred with the breaststroke and butterfly stroke. Finally, back injuries were associated with the butterfly stroke. During the freestyle stroke, the shoulder undergoes repetitive overhead movement; hence, shoulder and musculoskeletal pain are the most common and well-documented complaints of swimmers. For safety management, coaches and instructors must ensure that athletes do sufficient warm-up and cool-down exercises to avoid injuries. In case of an injury, they should be familiar with first aid measures so that secondary damage can be prevented with its quick application. In addition, coaches and instructors need to be trained in injury prevention and treatment so that they can provide appropriate rehabilitation treatment for athletes. Although swimming-related injuries cannot be completely eliminated, to reduce them to a minimum, leaders need the knowledge to apply scientific and systematic training principles and methods individualized for each athlete.

• Journal of the Korean earth science society
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• v.41 no.5
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• pp.490-503
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• 2020

Oceanic current and circulation have played an important role as regulators of the earth's energy distribution. The science and earth science textbooks for secondary schools based on the 2015 revised curriculum included a misconception of the seasonal variation of the North Korea Cold Current (NKCC) among the currents around the Korean Peninsula. To analyze this, the contents related to the NKCC were collected in the textbooks of five middle and six high schools, and a questionnaire survey was conducted on 30 middle school science teachers. The survey consisted of questions about whether the textbook mentions the NKCC and whether there is an error in the concept of the temporal variation of the NKCC, and the teachers' free opinions related to the NKCC were collected. The textbooks suggest that the NKCC is strongest in winter, which is not consistent with scientific findings so far. In fact, there is scientific evidence that the NKCC is the strongest in the summer. In this study, the causes and processes of misconceptions were investigated. According to an analysis of the survey, most teachers had an knowledge that the NKCC is stronger in winter. These errors began with a misconception of the terms, which teachers had imprinted on their memory as firm knowledge. These misconceptions originated from the knowledge that teachers themselves acquired from their secondary school years and have long been transferred back to teachers and students without revising the misconceptions of textbooks. This situation is expected to have a seriously recurrent structure that produces students' serious misconceptions in the future. Therefore, this study summarizes existing results on the seasonal variability of the NKCC and suggests the necessity for re-education to improve teachers' professionalism and to eliminate the misconceptions of teachers and students.

• Journal of The Korean Society of Grassland and Forage Science
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• v.27 no.4
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• pp.297-312
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• 2007

This study is conducted to evaluate economical value of Jeju grassland and validity of its preservation, and draw up several measures to support. To measure its economical value, this study examined its environmental value and social and cultural value. For environmental value, this study used replacement method while it applied CVM method, a widely used method, to assess social and cultural value and two-level two-best choice selection method, which ask questions by assuming virtual circumstances to avoid reflecting some biased opinions. Jeju grassland has multiple functions-environmental functions such as preventing soil corrosion and flood, handling animal excrement, and purifying air, and social and cultural functions such as promoting physical and mental health and providing recreation places. From the results of the feasibility study, Jeju grassland's annual multiple functions are assessed to have a total $397,115{\sim}418,995$ million won worth. In addition, it is found that Jeju visitors recognize Jeju grassland for its functions to contribute to public interests. That is, they think it can provide attractive views and educational and recreational places and promote emotional development. Especially, many people presented their ideas that it be continuously preserved since it is worthwhile for us and our next generations. To preserve grassland's cultural resource, which create a huge economic value like this, the Government has to support a certain amount of financial aid for turning to a better grassland environment and its maintenance to realize environment-friendly livestock farming on Jeju Island and promote its tourism industry and consequently, add more value to Jeju.

• Journal of the Korean Society for information Management
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• v.39 no.4
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• pp.191-213
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• 2022

With a view to providing a high-quality policy information service beyond the existing national task service of the national policy information portal (POINT) of the National Library of Korea Sejong, it would be necessary to effectively provide the policy data needed for the implementation of the new national tasks. Accordingly, in this study, an attempt has been made to find a way to connect and develop the BRM-based national tasks and the policy information contents. Towards this end, first, the types of national tasks and the contents of each field and area of the government function's classification system were analyzed, with a focus placed on the 120 national tasks of the new administration. Furthermore, by comparing and analyzing the national tasks of the previous administration and the current information, the contents ought to be reflected for the development of contents related to the national tasks identified. Second, the method for linking and collecting the policy information was sought based on the analysis of the current status of policy information and the national information portal. As a result of the study, first, examining the 1st stage BRM of the national tasks, it turned out that there were 21 tasks for social welfare, 14 for unification and diplomacy, 17 for small and medium-sized businesses in industry and trade, 12 for general public administration, 8 for the economy, taxation and finance, 6 for culture, sports and tourism, science and technology, and education each, 5 for communication, public order and safety each, 4 for health, transportation and logistics, and environment each, 3 for agriculture and forestry, 2 for national defense and regional development each, and 1 for maritime and fisheries each, among others. As for the new administration, it is apparent that science technology and IT are important, and hence, it is necessary to consider such when developing the information services for the core national tasks. Second, to link the database with external organizations, it would be necessary to form a linked operation council, link and collect the information on the national tasks, and link and provide the national task-related information for the POINTs.

• Korean Journal of Plant Resources
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• v.36 no.2
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• pp.107-121
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• 2023

This study analyzed the polyphenol, flavonoid contents, antioxidant activity, anti-aging activity and phenol component contents of Saccharina japonica (SJ), Costaria costata (CC) extracts with hot water, 95% methanol, 95% prethanol for investigating possible utilization of SJ and CC extracts. The result revealed that the SJ and CC methanol extracts showed the highest polyphenol and flavonoid contents, 4.63 mg TAN/g, and 4.19 mg QUE/g respectively. Also, the SJ and CC methanol extracts showed higher antioxidant activity than prethanol and hot water extracts, whereas the ABTS radical scavenging activities were the highest in prethanol extracts (IC₅₀ = 15.4, 10.3 ㎍/µL). In anti-aging activity for evaluating the anti-wrinkle activity and skin whitening activity, the CC methanol extracts had high collagenase inhibitory activity (88.3%), and the SJ prethanol extracts showed higher elastase inhibitory activity (19.0%) compared to other extracts. Then the tyrosinase inhibitory activity was significantly higher in the SJ and CC methanol extracts (41.8, 30.3%, respectively), whereas prethanol extracts were the lowest. To identify the phenol component contents of SJ and CC extracts, 4-hydroxybenzoic acid, naringenin, naringin and nicotinic acid were measured using LC-MS/MS. As a result, the phenol contents were the highest in SJ methanol extract (4-hydroxybenzoic acid), SJ and CC prethanol extract (naringin and naringenin) and CC prethanol extract (nicotinic acid). Lastly, the antioxidant activity of SJ and CC showed high correlations with polyphenol and flavonoid contents (R = -0.946~0.883). These results suggest that prethanol or methanol extracts of SJ and CC have higher antioxidant activities, anti-aging activity and the potential to be used as material for health functional food and cosmetics.