• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.5
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• pp.677-697
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• 1995

The analysis of long- period sea level variations with tidal record data around Korea, Japan, and Russia shows that about half of the variations are due to atmospheric influences. The sea level variation by water movements is the largest in the coasts along the Tsushima Current, and becomes smaller in the distant areas. It suggests that the sea level varications are related with the Tsushima Current. The effect of sea level variations to ocean circulation has been studied with a numerical model allowing barotropic sea level fluctuations, like the result with GCM (Semtner) model by Pang et al.(1993), the present model also shows that waters basically flow along isobaths over the last China Sea after geostyophic adjustment around Taiwan. However, barotropic sea level fluctuation makes the basic circulation in the Yellow Sea, which waters flow into the central Yellow Sea and out along the west coast of the Korean Peninsula. Besides this, barotropic sea level fluctuation makes long period waves over the shelf area as the Kuroshio varies. By the waves, the basic circulation in the Yellow Sea is disturbed, so that the flow pattern of oppositely flowing into the Yellow Sea along the west roast of the Korean Peninsula appears. In the Yellow Sea circulation, it seems that northwest winds strengthen the basic circulat ion In winter, and southeast winds strengthen the disturbed circulation in summer. Another point appeared by the long period wave is that the Tsushima Current possibly originates in different areas. There have been two opposing argues on the area in which the Tsushima Current originates the southwest sea of Kyushu Island and the adjacent sea of Taiwan. Through this study, we found that both of them seem to be important areas for the origin of the Tsushima Current, and one of them is possibly strengthened by long period waves. The long period waves given by the variation of the Kuroshio Current in the adjacent sea of Taiwan propagate to the Korea Strait as forced waves. The wave continuously propagates to the last Sea through the eastern channel, but reflects in the western channel due to bottom topography. The reflected waves propagate southwestward along the last China Sea as free waves and determine the sea level variations with forced waves.

• Journal of the Korea Organic Resources Recycling Association
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• v.15 no.4
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• pp.115-124
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• 2007

The material compressions in the vertical composting reactor affect to the biodegradation rates of the organic wastes. This study investigated the variations of physical properties of the composting materials according to the height of reactor due to affect to the settlement in the vertical composting reactor. The variations of decreased temperature after peak temperature showed the different patterns depending on the reactor heights. The variation width of re-increased temperature after peak temperature was reduced as the mixing operations were increased, and increased as the height of reactor elevated. The moisture content and the variation width of the moisture content were increased higher as the height of the reactor became higher. The variations of the bulk density at each height of vertical reactor showed the same tendency comparing with those of the moisture content. The relationship between bulk density and moisture content had shown the quadratic equation (r2=0.94). The dry solid contents at each reactor height were decreased as the height of reactor were increased. The results of the variation of the physical properties during the composting process were caused by the downward compression of the material into the reactor. Settlement rate in the vertical composting reactor was estimated about 2.184cm/day. To increase the biodegradation efficiency in the vertical reactor, the conditions of air path in the composting material matrix have to be investigated afterwards.

• Korean Journal of Environment and Ecology
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• v.24 no.3
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• pp.249-257
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• 2010

The purpose of this paper is to weigh the possibility of endangered Jang-hang wetland at the estuary of Han River to be included on the Ramsar List of Wetlands of International Importance and come up with ways to manage the wetland depending on its biotope patterns. The target area is located between Gimpo bridge and Isanpo I.C. with about $2.7km^2$ area. Through the analysis of RIS(Information Sheet for Ramsar Wetlands), it was known that the wetland is located on the sedimentary topography and formed as a result of sediment at the estuary of the river owing to the concentration of rainfall during summer. The vegetation environment in the area is divided into brackish water and fresh water areas depending on salinity. Rhizosphere soil(RS) of the area was analyzed to be Silt loam while bottom RS to be Sand loam. The plant ecology was composed of 52 families 135 species and 11 varieties and 146 types. Among indigenous species found are Salix koreensis, Phragmites communis and Miscanthus sacchariflorus. The analyzed results of the actual vegetation showed that willow community accounts for 37% of the area and rice field is 13.5%. As for animal ecology, total of 62 species and 25,977 individual wild birds were observed. After comparing and analyzing the RIS we compiled with the Ramsar Site designation standards, it turns out that the Jang-hang wetland meets criteria 1(biographic region), criteria 2,3 and 4(species and ecological communities) and criteria 5 and 6(water birds). Thus, Jang-hang wetland is eligible for the Ramsar site. As a result of establishing and evaluating the biotope types for setting management areas, Jang-hang wetland has a total of 13 different types, and the grade I represents 75.4% of the area while the grade III 0.8% of the land status. We categorized four management zones for the wetland depending on the biotope patterns - preservation, restoration, use and buffer zones and suggested management methods for each zone.

• The Korean Journal of Air & Space Law and Policy
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• v.22 no.1
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• pp.29-54
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• 2007

Nuclear Power Sources(NPS) have been used since 1961 for the purpose of generating energy for space objects and have since then been recognized as particularly suited essential to some space operations. In January 1978 a malfuctioning Soviet nuclear powered satellite, Cosmos 954, re-entered the earth's atmosphere and disintegrated, scattering radioactive debris over a wide area of the Canadian Northwest Territory. This incident provided some reasons to international legal scholars to make some principles to regulate using NPS in outer space. In 1992 General Assembly adopted "Principles Relevant to the Use of Nuclear Power Sources in Outer Space". These NPS Principles set out certain legal and regulatory requirements on the use of nuclear and radioactive power sources for non-propulsive purposes. Although these principles, called 'soft laws', are not legal norms, they have much enfluences on state practices such as 1983 DBS Principles(Principles Governing the Use by States of Artificial Earth Satellites for International Direct Television Broadcasting), 1986 RS Principles(Principles Relating to Remote Sensing of the Earth from Space) and 1996 Declaration on International Cooperation in the Exploration and Use of Outer Space for the Benefit and in the Interests of all States, Taking into Particular Account the Needs of Developing Countries. As far as 1963 Declaration of Legal Principles Governing the Activities of States in the Exploration and Use of Outer Space is concerned the main points such as free use of outer space, non-appropriation of celestial bodies, application of international law to outer space etc. have become customary international law binding all states. NPS Principles might have similar characters according to states' willingness to respect them.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.9
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• pp.1235-1241
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• 2012

Antioxidant properties and antioxidant compound contents in different parts of 14 commercial mushrooms were evaluated. Methanolic extracts from the entire mushroom, the pileus and the stipe, separately, were screened for their DPPH and ABTS free radical scavenging activities. Total ubiquinones (Coenzyme Qs; CoQs), total phenolic, and flavonoid contents were determined, in order to assess the extract's antioxidant activity. The portion of the mushroom selected had an effect on the results, with pileus methanolic extract exhibiting the greatest antioxidant effect (p<0.05). The analyzed mushrooms contained powerful antioxidants such as phenols (144.5~536.6 mg of gallic acid equivalents, mg GAE/100 g of dried weight, dw), flavonoids (3.7~31.2 mg of quercetin equivalents, mg QE/100 g dw) and ubiquinones (65.6~485.1 ${\mu}g$/100 g dw). Content of CoQ9 and CoQ10 in the 14 commercial mushrooms varied from 23.1 to 256.2 ${\mu}g$/100 g and from 16.1 to 238.3 ${\mu}g$/100 g, respectively. Phellinus linteus showed the highest antioxidant activity among all species due to the contribution of antioxidants such as phenols (530.5 mg GAE/100 g dw) and ubiquinones (308.8 ug/100 g dw). A positive linear correlation was demonstrated between free radical scavenging activity and total phenolic ($R^2=0.79$) and ubiquinone ($R^2=0.59$) contents in the pileus of mushrooms (p<0.05). Our data indicate that commercial mushrooms have potential as dietary sources of CoQs and phenolic antioxidants.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.10
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• pp.1258-1263
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• 2008

The current study examined the effects of radish leaves powder on the excretion of fecal triglyceride, and sterol and hepatic UDP-glucuronyl transferase (UDPGT) activity in rats fed hypercholesterolemic diet. Male Sprague-Dawley rats weighing 100$\pm$10 g were randomly assigned to normal control group (N group), normal diet with 5% radish leaves powder supplemented group (NR) and hypercholesterolemic groups, which were sub-divided into radish leaves powder free diet group (HC) and 2.5% (HRL), 5% (HRM), and 10% (HRH) radish leaves powder supplemented groups. The experimental diets were fed ad libitum for 4 weeks. Fecal weights and water contents were significantly increased in all radish leaves powder supplemented groups (NR, HRL, HRM, and HRH) than that of N and HC groups. Fecal total lipid contents including fecal neutral and acidic sterols in radish leaves powder supplemented groups were higher than those of the HC group, and especially that of HRH group was the highest among all experimental groups. Hepatic UDPGT activity of HRH group was 38% higher than that of HC group. Excretions of fecal bile acid were increased 2.3 and 2.7 folds in HRM and HRH groups compared with that of HC group. And neutral sterol, coprostanol, and coprostanone contents of them were higher in radish leaves supplemented groups than in HC group. These results suggest that radish leaves may act as potential substitute for a dietary fiber capable of improving a gastrointestinal function and lipid metabolism.

• Korean Chemical Engineering Research
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• v.56 no.3
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• pp.309-314
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• 2018

In this study, methanol extracts of the Oxalidaceae were tested with a potential functional cosmetic agent. As cosmetic agent tests, cell toxicity, polyphenol content, antioxidation, anti-wrinkle, and whitening effects were measured. Cell toxicity of the extracts was weak up to $1,000{\mu}g/mL$. Polyphenol contents of Oxalis corniculata L., Oxalis obtriangulata Maximowicz and Oxalis articulata Savigny were $116.036{\pm}0.37mg/g$, $54.72{\pm}0.52mg/g$ and $88.18{\pm}1.15mg/g$, respectively. Oxalis corniculata L., Oxalis obtriangulata Maximowicz and Oxalis articulata Savigny extracts showed 89%, 80% and 88% of antioxidation effects at $1,000{\mu}g/mL$ concentration using DPPH free radical scavenging assay. Oxalis corniculata L., Oxalis obtriangulata Maximowicz and Oxalis articulata Savigny extracts indicated 81%, 51% and 57% of antiwrinkle effects at $1,000{\mu}g/mL$ concentration using elastase inhibition assay. Oxalis corniculata L. extract was particularly excellent in elastase inhibition effect. Whitening effect using tyrosinase inhibition assay was relatively weak. Lotion formulation including 1% Oxalis obtriangulata Maximowicz extract was stable based on the temperature stability test for 28 days in terms of pH, viscosity and appearance. However, Lotion formulation including 1% Oxalis corniculata L. extract and Oxalis articulata Savigny extract need formulation improvement. From the research, methanol extract of Oxalis corniculata L. seems to be good candidate for antiwrinkle functional cosmetic agent.

• Journal of Korean Society of Forest Science
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• v.67 no.1
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• pp.17-27
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• 1984

The Yangsan Forest Management Station (YFMS) of Korean German Forest Management Project (KGFMP), working with the 6 legal villages of Uljugun, Kyongnam, led the forest owners in the area to organize the Forest Management Cooperative (FMC) voluntairily for improvement of private forest management and fostered it as a model from May 1975 to Apr. 1984. YFMS sent out FMC a forest manager as a forestry expert carrying out the leading extension program at the equal position with forest owners and gave FMC financial, administrative and technical assitances. During the 6 years from 1977 to 1982, 4 FMC were founded and are being operated democratically. 228 forest owners have taken the membership of their own free will and the forestland of the members covers 2,567 ha equivalent to 57% of the total private forest in the area. During the period the total area of the planting and tending is 4,185 ha, this means that a member executed 3.1 ha of forest operations per year in average, showing the high willingness on forest operations. In addition the joint works have resulted in the joint properties equivalent to 27 million Won and it will be an important foundation for operation of FMC which is a forest owners's cooperative organization for improvement of private forest management in this area. The total expenditure spent for the fostering of FMC amounted to 497,587 thousand Won and 58% of them were charged from KGFMP funds, 27% from the forest owners and 15% from public funds. The expenditure for investment was 273,104 thousand Won and 59% of the sum were appropriated as subsidies at the national level. The forest owners charged 43% of that and this means that each member invested approximately 100 thousand Won to his forestland per year in average. For the extension program 169,503 thousand Won were spent and it can be explained that 5,885 Won were spent per ha a year. The organization of FMC operated autonomously in a democratic way and the horizontal and leading extension system, which aspects the human rights, were very much effective in fostering the cooperative organization of forest owners for improvement of private forest management.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.12
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• pp.131-138
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• 2016

In this study, we tried to analyze the influence of ICM(Iodinated Contrast Media) in MR imaging compare to GBCA(Gadolinium Based Contrast Agent), and as this result we discussed whether resonable or not the protocol which is MRI scan after enhanced CT scan without proper time interval in clinical field. For this research, we assembled two phantoms. which one was iodine and another one was gadolinium. We did test two phantoms in conventional MRI scan which is T1, T2, T2 FLAIR and 3D angio. After that, quantitative analysis was progressed. The results of study were as follow : SSI(Saline's Signal Intensity) was shown as each sequences 175, 1231, 333, 37 [a.u] at iodine. and 1297, 123, 757, 232 [a.u] was recorded at gadolinium. BDEPS(the Biggest Difference of EPS) was shown as each sequences 1297, 123, 757, 232 [a.u] at iodine and 793, 6, 1495, 365 [a.u] was recorded at gadolinium. At this time, EPS(Enhancement Percentage to Saline) was shown 641.1, -90.0, 127.3, 527% at iodine and 685.1, 99.4, 365.7, 1077.4% was recorded at gadolinium. BP(BDEPS's point) was shown 900, 900, 477, 900 mmol at iodine and 4, 0.2, 0.2, 40 mmol was recorded at gadolinium. CPSS(Change Point of SI to SSI) was shown 63, 423, 63, 29 mmol at iodine and each [50, 30], [4, 0.2], [4, 1], 0.2 mmol was recorded at gadolinium. According to this research, we could not only discover the fact that was iodine could effect on MR signal, but also the pattern is different as various sequences compare to gadolinium. Therefore, we expect useful diagnostic MR image in clinical field with this quantitative data for deciding protocol regarding MRI and CT scan order.

• Journal of The Korean Association For Science Education
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• v.19 no.2
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• pp.239-247
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• 1999

This study is to make suggestion for developing textbook systematically by analyzing biological contents and organization in science textbooks which are important instructional media to accomplish objectives of the 6th middle school science curriculum. The inclusiveness degree of the 6th science educational objectives reflected in the textbooks was analyzed by Klopfer's and the Korean Educational Department's objectives taxonomy. And the biological contents and the organization of the science textbook were analyzed by learner, subject matter, and society dimensions which are selecting criteria for curriculum objectives suggested in Tyler's curriculum model. The analyzed results are as follows: 1. The inclusiveness degree of the educational objectives was very low. 2. Regarding the dimension of learner, the concepts of formal operational cognitive level were much increased as grade becomes higher. And the degree of learner's interests reflected on the learning topics and domains was very low. 3. Regarding the dimension of subject matter, the concept-centered learning was increased, in relation to inquiry learning as grade becomes higher. The analyzed results of inquiry subskills showed that observation, classification, and recording skills in 1st grade, observation and operation skills in 2nd grade, and interpreting data skills in 3rd grade were centered. As the problems and processes were presented, so most of inquiry activities had low openness scale. The learning contexts were organized into discipline-centered in relation to real life. 4. Regarding society dimension, the learning topics of environments and health were much presented. but those of biotechnology and career were presented scarcely. And most learning topics related society dimension were organized in textbooks of the 2nd and 3rd grade. These suggested that to accomplish curriculum objectives effectively. the inclusiveness degree of educational objectives is to increase and, the contents and organization of textbook were constructed harmoniously in aspects of learner, subject matter and society dimensions.