• Proceedings of the KIEE Conference
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• 1999.11b
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• pp.219-221
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• 1999

HVDC(High Voltage Direct Current) transmission system was constructed between Cheju island and mainland Haenam and has been operating commercially since 1998. But research activities in this area are not so much. That is caused by the facts that HVDC is large scale system and it is not so easy to implement and to test. Though such simulation tools as RTDS(Real Time Digital Simulator) and EMTDC can be useful, these have limitations for actual control and protective system design. Therefore scaled-down HVDC model was developed for the purpose of researches at operating technique, control and protection methods. The design of this model was based on real Cheju-Haenam HVDC system. And additionally faults simulator such as ground fault, short-circuit and change of impedance in transmission line is equipped for analysis of these faults. Control system of the model was implemented fully digitally. So it is very easy for the researchers to develope control and protection algorithm and to test the performance.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.spc1
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• pp.123-131
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• 2006

Immmune parameters of the Manila clam Ruditapes philippinarum collected from four tidal flats, Nudong, Gonam, Hwangdo and Bangpo on Anmyeon-do, Korea were optimized and evaluated at the single cell level using flow-cytometry Hemocytes were withdrawn from the sinus of each clam, and total hemocyte counts (THC), phagocytosis rate, hemocyte mortality (HM) and DNA damage of hemocyte were analyzed. The highest hemocyte counts was recorded from the clams collected from Gonam, followed by Hwangdo, Nudong and Bangpo (P<0.001). Phagocytosis rate and hemocyte mortality of Gonam and Nudong clams were significantly higher than those of clams from Hwangdo and Bangpo (P<0.001). DNA damage in the clams from Nudong was higher twice than that of clams from Gonam (P<0.05). We suggest that the flow-cytometry has a high potential for evaluation of immunity of marine bivalves.

• The Plant Pathology Journal
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• v.20 no.2
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• pp.110-114
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• 2004

Through in vitro screening for biocontrol agents (BCAs) against Streptomyces scabiei causing potato (Solanum tuberosum) common scab, 19 streptomycete and 17 fungal isolates with antagonistic activity were selected as BCA candidates. For the selection of BCA candidates which are highly resistant to 10 kinds of antibiotics or pesticides, chemical susceptibility testing was initially performed in vitro. A remarkable degree of variation in susceptibility to antibiotics or pesticides was observed among the isolates tested. Streptomycete A020645 isolate was highly resistant to all the tested chemicals except neomycin up to 5,000 ppm. On the other hand, out of 36 antagonistic microbes subjected to in vivo pot tests using cultivar Daejima, four streptomycete isolates namely, A020645, A010321, A010564, and A020973, showed high antagonistic activity with >60% and 55% control value, respectively, and high chemical resistance to 10 kinds of chemicals. Therefore, these isolates were selected as potential BCAs for the control of potato common scab.

• Journal of Family Resource Management and Policy Review
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• v.11 no.3
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• pp.81-105
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• 2007

This research aimed to understand the awareness of married couples who have children over the age of elementary school age. What do they perceive as a wholesome and healthy family? What are they doing to promote the wholesomeness of the family? What are their demands of society and the government? Twenty-five people, 13 husbands and 12 wives, comprised the total number of subjects. The data were analyzed after in-depth interviews. The results of the research were as follows. First, all the subjects had no clear idea about the basic laws of a wholesome and healthy family although they were in the class belonging to the educational sector. Their awareness of what constituted a wholesome and healthy family included such things as physical, mental, ethical, and even spiritual health. Second, the married couples mostly answered that they were trying their best to promote the health of their families. This was basically related to the promotion of physical and mental health.

• Korean Journal of Applied Biomechanics
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• v.13 no.2
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• pp.139-160
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• 2003

The purpose of this study was to suggest the guideline for scientific and quantitative skill acquisition methods of badminton smashing so that the novice could learn the motions of badminton smashing efficiently. The subject participated consisted of total 6 middle school students of the stilled(3) and the unskilled(3). The cinematographical experimental & Analysis equipments used in the study were composed of two Model D-5100 Video Cameras, a control point, a synchronization timer and Kwon3d motion analysis system. The conclusions obtained were as follows, 1. It was necessary for the unskilled to learn the smashing impact phase in situation of max. velocity of COG in order to minimize the timing loss phase. 2. Particularly. The power from segments of Power Zone must participate in utilization in sequence of order of trunk-upper arm- forearm-hand-racket segment in both the skilled and the unskilled.. 3. Therefore it was necessary for the unskilled to do smashing practice for cumulated sum of absolute & relative velocity transfer into shuttle cock after adjusting anterior-posterior tilting angle and max timing, in sequence of segment recruited.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.3 no.1
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• pp.23-31
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• 1999

An advanced mobile technology is described for saturating water with oxygen. The MTR(Mass Transfer Reactor) is 2~10 times more effective in dissolving oxygen in water compared to most other systems used in aquaculture, because it can generate extremely small(0.005~0.05mm) bubbles. New fish farming facilities could make use of this technology to build deeper ponds for raising multiple species with optimized conditions for DO(dissolved oxygen), food, light, etc. The proposed technology offers higher DO levels with minimal operating costs. It is easy to use and maintain, with a high reproducibility. Accordingly, the MTR can be industrially applied in the treatment of fish waste and reduction of water consumption during fish farming.

• Journal of the Korean Institute of Landscape Architecture
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• v.23 no.1
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• pp.67-94
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• 1995

A total of 394 plant species in 74 families planted in home gardens, public building gardens, campuses of elementaiy, middle, and high schools, and universities, recreation areas, city parks, loeal and national ways, and highways from 1.21 local areal in Korea were surveyed- A comparison of the surveyed species to nation-widei.y growing species in those areas were studied. the results obtained were as follows : 1. The ratio of evergreen to deciduous plant species was 38.1:61,9 and that of tree:scrub:vine was 54:40.9:5.1. 2. The ratio of evergreen to deciduous plant species was 27.5:72.5 among total 276 land-scape plant species surveyed in Seoul and Kyongki-do province. The ratios were 32:68 in Kwangwon-do, 36.1:63.9 ill Chungchongbuk-do, 37:61 iii Chungchongnanl-do, 36.4:63.6 in Kyungsangbuk-do, 39.2:60.8 고 Kyungsangaaal-do, 35.7:64.5 in Jollabuk-do, 40.6:59.4 in Jollanam-do, and 43.1 :56.9 in Cheju-do. This results tell that more evergreen species are growing in the southern than in northern region in Korea. 3. Plants with 100% frequency in national planting were 8 species inclubing Forsythia koreana 91-99% were 6 species including Taxus cuspidata, 81-90% were 13 species including Magnolia liilflora, 71-80% were 10 speces including Buxus microphylla val, koreana, 61-70% were 13 species including Thuja occiduntakus, 51-60% were 15 species including Pius thunbergii, 41-50% were 15 species including Kerria japonica, 31-40% were 17 species including Cryptomeria japonica, 21-30% were 28 species including Viturnum awabuki, and below 20% were 267 species including Koelreuteria paniculata. 4 Uppermost north latitude of planting distribution of major temperature species was sum- marized as follows: Although it has been reported that Cryptomeria japonica is possible to grow in areas around -47, the result from this study shows that Cryptomeria japonica grows normally in Choonchun Seoul, Samchuck, and Kwangryeung, etc. , and is possible to grow normally in the areas with approximately -6$^{\circ}C$ in an average temperature in January, where are -2$^{\circ}C$ colder than the reported temperature, but locally warm Phyllostachys bambusoides is distributed to Mt. Kumkang and Mt. Sulak, and also planted in Seoul, Kwangryeung, and Chunchon.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.4
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• pp.251-264
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• 1992

Distribution of indicator species of copepods and chaetognaths were studied as an indicator species of water mass in the southeastern area of the Yellow Sea. Undinula darwini, Lucicutia flavicornis, Pleuromamma gracilis, Euchaeta resselli, Euchaeta plane and Sagitta enflata were found to be reliable indicator species for determining warm water mass. Of these species, E. plana and E. rusrelli have a weak tolerance on the low temperature. Sagitta crassa was indicator species of neritic waters; Sagitta bedoti was that of mixing waters. Centropages abdominalis represented neritic cold waters. In February, U darwini, L. flavicornis, P. gracilis, E. russelli, E. plana and S. enflata occurred in the western waters of Cheju-Do where warm waters over $14^{\circ}C$ occupied. Centropages abdominalis occurred in the northern area beyond Chindo with water temperature less than $10^{\circ}C$. E. plana, E. russelli and S. bedoti were found at the regions between Cheju-Do and Chindo where the water temperature was $12- 14^{\circ}C$ corresponding to the mixing waters. Based on cluster analysis and T-S diagram in February three different water masses were identified from the south to the north. In August, water masses were analyzed at two different layers, 0-20m and 20m- bottom layers, separated by bhermocline depth. In 0-20m layer, E. plana and E. russelli were found from the western waters of Cheju-Do to Daehuksando. In 20m- bottom layer, E. russelli and E plena occurred at the northwestern waters of Cheju-Do with the water temperature warmer than $12^{\circ}C.\;C.$ abdominalis was found at the northern area beyond Chindo. Based on the cluster analysis and T-S diagram in August three different water masses at 0-20m and 20m-bottom layers were identified from the coast to the offshore. C. abdominalis was found at the adjacent water of Chindo at 0-20m layer and the northern area beyond Chindo at 20m~bottom layer. This fact suggested that the cold water mass existed at tile adjacent waters of Chindo in summer.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.4
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• pp.380-385
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• 1988

The present study was conducted to evaluate agronomic characters of the soybean germplasm which was collected from the sites covering whole areas of southern Korean peninsula. A total of 2,748 Korean native soybeans was grouped for fruiting period and in this group frequency distribution of the important agronomic characters and relationships among the characters were determined. The results obtained were summarized as follows; The soybean germplasm was comprised of SeoulㆍKyonggi-do 7.5%, Kangwon-do 13.3%, Chungchongbuk-6.6%. Chungchongnam-do 12.3%, Chollabuk-do 10.7%, Chollanam-do 12.6%, Kyongsangbuk-do 20.8%, Kyongsangnam-do 15.3% and Cheju-do 0.6% in number of collections. Frequency distribution of the germplasm for fruiting period was 0.14% in Group I (below 55 days). 1.67% in Group II (56-60 days), 10.58% in (Group III(61-65 days), 23.18% in Group IV(66-70 days), 25.91% in Group V(71-75 days) 19.79% in Group Ⅵ(76-80 days), 15.1% in Group Ⅶ(81-85 days) and 3.6% in Group Ⅷ(over 85 days). The lines over 70 days in fruiting period were as much as 64.4% of germplasm. The fruiting period varied largely from 45 days to 91 days. Fruiting period was positively correlated to seed weight, days to maturity, days to flowering, plant height and number of branches per plant, respectively. While. it was negatively correlated to number of pods, lodging and virus infectivity, repectively, and in particular negative correlation was shown significantly between yield and fruiting period. Average yield was very high as much a 1.389kg/ha in fruiting period Group I, and decreased with increment of fruiting period, 1.400kg/ha in Group II. 1.384kg/ha in Group III. 1,299kg/ha in Group IV, 1,197kg/ha in Group V, 1,117kg/ha in Group Ⅵ, 967kg/ha in Group Ⅶ and 832kg/ha in Group Ⅷ.

• Journal of the Korean earth science society
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• v.26 no.3
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• pp.240-252
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• 2005

The relationships between wave and wind around the Korean Peninsula have been analyzed with the data from the buoys moored at five stations (Dugjug-do, Chilbal-do, Geomoon -do, Geoje-do, Donghae) by Korea Meteorological Administration. Generally, the relationship between wave and wind is the highest at the stations in the West Sea and the lowest at the stations in the South Sea, and the middle at the station in the East Sea. The characteristics shown at each station are as follows. Highest wave is developed at Chilbal-do with strong northwesterly wind in winter because the sea is opened in the wind direction and wave is amplified by shoaling effect. At Chilbal-do, wave directions coincide with wind directions relatively well. On the other hand, waves are not fully developed at Dugjug-do in winter due to limited fetch since the sea is blocked by Hwanghae-do in the northwest direction. The limitation in fetch is more serious at the stations in the South Sea. In the South Sea, the direction of dominant northerly wind is blocked by land so that wave heights are small even with very strong northerly wind. In the South Sea, whatever wind direction is, waves dominantly come in the direction from the East China Sea, which are from the south at Geomoon-do and the southwest at Geoje-do. At these directions, waves are coming even with weak wind. At the station in the East Sea, waves are highly developed due to vast area, but not so high as in Chilbal-do because wind and wave directions do not coincide in many cases. As shown, wind direction is important in the wave development as well as wind speed. The reason is that the fetch is determined by wind direction. In the case of long-lasted wind with fixed direction at Chilbal-do and Dugjug-do, wave directions are well coincident with wind directions and wave heights increase with response time, which is the duration between the highest wind and wave. However, in the case of disagreement between wind and wave directions at the station in the East Sea, wave heights do not increase as highly as at Chilbal-do and Dugjug-do in spite of strong wind and longer response time. The results show us that waves are highly developed with strong wind, long fetch, and long duration, and also show that wave development ratios are different at different stations due to environmental factors such as the direction towards sea or land, bottom topography, and the scales of adjacent seas.