• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.6
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• pp.568-577
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• 2002

The spreading Cocuoainim polykikoides bloom in the southern coastal waters of Korea was simulated using numerical model including the physical processes of water flow and the chemical processes of increasing cell of C. polykikoides by uptake of dissolved nutrients. The circulation of sea water was simulated by two dimensional tide model reflecting the main four tidal components of $M_2,\;S_2,\;K_1,\;O_1$, and permanent current was driven by inflow/outflow across open boundaries. According to the result of model which tidal and permanent current were reflected simultaneously, eastward flows entering the southern waters from the western waters of Korea are dominant but westward flows are weak relatively. These result suggest that it is difficult for initial C. polykikoides bloom generated in the coastal waters of Goheung to move to the western coast of Korea through Jeju Strait. For spreading model of C. poiyhikoides, the range of generating distribution and the generating time of C. polykikoides bloom in coastal area are similar to those of observation data in the field. Wind is the most important factor in moving and distribution of red tide. Permanent current flowing eastward is also considered to be important factor and tidal current was a little influenced.

• Journal of Preventive Medicine and Public Health
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• v.29 no.4 s.55
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• pp.843-851
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• 1996

To estimate the incidence of uterine cervix cancer among Korean women, we have conducted a study using the claim data on the beneficiaries of Korea Medical Insurance Corporation (KMIC). All medical records of the potential cases with diagnosis of ICD-9 180, 181, 182, 199, 219, 233 in the claims sent by medical care institutions in the whole country to the KMIC from January 1988 to December 1989, were abstracted and Gynecology specialist reviewed the records to identify the new cases of uterine cervix cancer among the potential cases during the corresponding period. Using these data, the incidence of uterine cervix cancer among Korean women was estimated as of July 1, 1988 to June 30, 1989. The crude rate was estimated to be 17.34(95% CI: $16.76\sim17.92$) per 100,000 and the cumulative rates for the ages $0\sim64\;and\;0\sim74$ were 1.7% and 2.2%, respectively. The age-adjusted rate for the world population was 19.93 per 100,000 which was higher than those of other Asian countries including China and Japan in $1983\sim1987$. The truncated rate for ages $35\sim64$ was 52.05 per 100,000 which was one of the highest in the world. With increasing age, the incidence rate increased to 78.11 per 100,000 in women aged $55\sim59$ years, then it decreased in the older groups. This finding suggests that detecting rate of uterine cervix cancer may decrease in women aged 60 years or older due to inadequate medical care seeking behavior. In the geographical area, the SIR of Jeju province was significantly low but it might be due to statistical unstability by small case numbers.

• Korean Journal of Breeding Science
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• v.43 no.3
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• pp.172-176
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• 2011

'Suan' is a new $F_1$ hybrid variety of rapeseed (Brassica napus L.) with early maturing and high oleic acid. This hybrid variety was bred by the cross between Mokpo-CGMS (male sterile line) and 8516-B-5-6-5-3 (restore line) for the production of bio-diesel and edible oil in 2006. 'Suan' has green and parted leaf, yellowish flower, and black seed coat. 'Suan' is more tolerant to lodging and stem rot compared to 'Sunmang', check variety. The ripening date of 'Suan' is June 2nd which is 6 days earlier than 'Sunmang'. Yield trials were conducted from 2006 to 2007 and regional adaptation trials were examined at five locations each in 2008 and 2009. The average seed yield of regional adaptation trials was 381 kg/10a that was 4% higher than that of 'Sunmang'. Total oil content of 'Suan' was 44.3%. Oleic acid content was 68.3%, which is 5.2% higher than 'Sunmang' but, erucic acid was not detected. Total glucosinolate content was 2.31 mg/g. Therefore, this variety is recommended as a leading variety at southwestern area including Jeonnam, Jeonbuk and Kyongnam provinces of South Korea.

• KEPCO Journal on Electric Power and Energy
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• v.5 no.3
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• pp.141-147
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• 2019

Recently, the biggest issue in the electricity industry is the increase in renewable energy, and various technologies are being developed to ensure the capacity of the power system. In addition, super-grids linking power systems are being pushed to utilize eco-friendly energy between countries and regions worldwide. The HVDC transmission technology is required to link the power network between regions with different characteristics of the power system such as frequency and voltage. Until now, Korea has applied HVDC transmission technology that connects mainland and Jeju Island with submarine cables. But, the HVDC transmission technology is still developing for long-distance high-capacity power transmission from power parks on the east coast to load-tight areas near the metropolitan area. Considering the high population density and mountainous domestic environment, it is pushing for commercialization of the design technology of the ${\pm}500kV$ Double Bipole with metallic return wire transmission line to transmit large-scale power of 8 GW using minimal right of ways. In this paper, the insulation characteristics were studied for the design of double-bipole transmission tower with metallic return wire, which is the first time in the world. And the air insulation characteristics resistant to the various overvoltage phenomena occurring on transmission lines were verified through a full-scale impulse voltage test.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.6
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• pp.671-676
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• 2014

Based on the data of PSC information management system of MOF(Ministry of oceans and fisheries) and APCIS(Asia-Pacific Computerized Information System) of Tokyo-MOU information system, the result of the evaluation on the reality of PSC was done, and base on 2009, it showed a trend of decrease in every DFR(Deficiency Rate) and DTR(Detention Rate). But for vessels built for more than 30 years, flags of convenience vessels, RO-RO ferry and general cargo vessel, small size vessels with gross tonnage less than 1,000 ton showed a high DFR and DTR. Each harbours is classified by the total harbours' average DFR which was 82.5 % and the average DTR was 5.1 %, excluding the Jeju harbour, showing a hugh deviation for classification of each harbour. Classification of each harbour has to be inspected by PSC and it showed a great unbalance of the number of vessels for each territory for inspection. the biggest problem with our country's PSC, where it was pointed out by the PSCO was lack of workers and independent inspection by just one worker. To strength the substantiality of the inspection of our country is to have concentrated inspection on the high risk cautious vessels, forming a human network each classified by four different sectors of the area, recalculating the amount of assignment of inspection classified by each harbour and securing workforce the PSCO improvements are necessary.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.153-159
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• 2019

Job creation is the most important issue in the labor market these days, and the quality of jobs is also very important in order to resolve the mismatches that are taking place in the labor market. Kim Young-min (2014) developed the "2012 Quality of Employment Index" with twenty indicators in seven categories, including employment opportunities, to objectively assess the local labor market. This method presents the concept of the aggregate indicator, 'Quality of Work Index', and has the advantage of being easy to produce. However, it is difficult to statistically verify the adequacy of the constitutive indicators and, based on this, make them a single aggregate index through statistical techniques. Therefore, we developed an alternative '2012 Descent Work Index' and a confidence interval using Principal Component Analysis(PCA) and Unobserved Component Model(UCM) presented by Gi-Choon Kang & Myung-jig Kim (2014) and also calculated an alternative '2017 Descent Work Index' using the first half of 2017 local area labour force survey and compared its changes by region. The results of the empirical analysis show that the rank correlation coefficient between two methods of aggregating indicators, simple weight used in Young-min Kim's research, PCA method and UCM used in this study, were found to be statistically significant under 5% significance level. This implies that all methods are found to be useful. However, the PCA and UCM which determine scientific and objective weights based on data are preferred to Young-min Kim's approach. Since it provides us not only the level of aggregate indicator but also its confidence intervals, it is possible to compare ranking with the consideration of statistical significance. Therefore, it is expected that the method of constructing an aggregating indicator using UCM will be widely used in many areas in the future.

• Journal of Climate Change Research
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• v.8 no.4
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• pp.415-424
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• 2017

This study was conducted to estimate carbon stocks of Pinus densiflora with drawing volume of trees in each tree height and DBH applying the suitable stem taper equation and tree specific carbon emission factors, using collected growth data from all over the country. Information on distribution area, tree age, tree number per hectare, tree volume and volume stocks were obtained from the $5^{th}$ National Forest Inventory (2006~2010) and Statistical yearbook of forest (2016), and method provided in IPCC GPG was applied to estimate carbon stock and uptake. Performance in predicting stem diameter at a specific point along a stem in Pinus densiflora by applying Kozak's model, $d=a_{1}DBH^{a_2}a_3^{DBH}X^{b_{1}Z^2+b_2ln(Z+0.001)+b_3\sqrt{Z}+b_4e^z+b_5(\frac{DBH}{H})}$, which is well known equation in stem taper estimation, was evaluated with validations statistics, Fitness Index, Bias and Standard Error of Bias. Consequently, Kozak's model turned out to be suitable in all validations statistics. Stem volume table of P. densiflora was derived by applying Kozak's model and carbon stock tables in each tree height and DBH were developed with country-specific carbon emission factors ($WD=0.445t/m^3$, BEF = 1.445, R = 0.255) of P. densiflora. As the results of analysis in carbon uptake for each province, the values were high with Gangwon-do $9.4tCO_2/ha/yr$, Gyeongsandnam-do and Gyeonggi-do $8.7tCO_2/ha/yr$, Chungcheongnam-do $7.9tCO_2/ha/yr$ and Gyeongsangbuk-do $7.8tCO_2/ha/yr$ in order, and Jeju-do was the lowest with $6.8tC/ha/yr$. Total carbon stocks of P. densiflora were 127,677 thousands tC which is 25.5% compared with total percentage of forest and carbon stock per hectare (ha) was $84.5tC/ha/yr$ and $7.8tCO_2/ha/yr$, respectively.

• Korean Journal of Heritage: History & Science
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• v.42 no.1
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• pp.62-70
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• 2009

The study was conducted from Jan. 11 to Jan. 12 2008 on 17 areas which were the wintering area of Aegypius monachus and where the birds were observed. In the study, a total of 1,912 individuals were observed to winter in the areas, which was larger than any previous observation. The study found that 1,500 individuals wintered in the central region of Korea including Gyeonggido and Kangwondo, which accounted for 78.45%, and 412 individuals (21.55%) in the southern region such as Gyeongbuk, Gyeongnam, Jeannam and Jejudo (Island). Given the number of individuals wintering by region, Jangdan Peninsula (777 individuals), Cheorwon (488 individuals) and Sancheonggun(193 individuals) were mostly found. In comparison with the previous studies, 20-30% of the individuals have moved south since 2006. This movement might be attributed to the suspension of feeding campaigns, but the birds still crowded some specific areas.

• Korean Journal of Plant Resources
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• v.34 no.5
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• pp.462-469
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• 2021

Maesa japonica (Thunb.) Moritzi & Zoll. is a rare evergreen shrub that occurs in west Gotjawal, Jeju island, Korea. This study was conducted to investigate effects of an artificial shading on flowering and growth characteristics of M. japonica seedlings. The level of shading had been set to be 35%, 55% and 75% using shading net. The stage of flowering and flowering ratio, seedling height, the number of leaves and stems, leaf area were measured. Flowering timings were delayed by shading. The number of flowering seedlings per plot and inflorescences per seedling were the most in 55% shading level. Tendency of decreased seedling height with increased shading level was shown. The number of leaves and stems were the fewest values in 75% shading level. The increased biomass with decreased shading level was statistically significant. Aboveground and underground biomass were 2.1 and 1.7 times higher in shading 35% than in shading 75%, respectively. Meanwhile, all seedlings in non-shading plots were dead in winter. Such might be speculated as results of the light stress. As a result, we conclude that M. japonica vitally demands the shading for growth and the optimal shading levels for growth and flowering are 35% and 55%, respectively.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.33 no.5
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• pp.187-194
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• 2021

The damage caused by typhoons is gradually increasing due to the climate change recently. Hence, many studies have been conducted over a long period of time on various factors that determine the characteristics of storm surge, and most of relationships have been discovered. Because storm surge is complexly determined by various factors, it often show different results and draw different conclusions. For this reason, this study was conducted to understand the various characteristics of storm surge caused by changes in the forward speed of typhoons. This study was carried out with a numerical model, and the effect of forward speed could be analyzed by simplifying other factors as much as possible. When forward speed is increased, storm surges caused by typhoons tended to increase gradually. The storm surge showed a wide and gentle increase at a slow speed, but a narrow and steep one at a fast speed. In the case of the same forward speed, it was found that the storm surge was significantly influenced by the water depth of actual sea area. It was confirmed that the change in forward speed after passing Jeju Island did not significant affect on the storm surge in the south coast of Korea.