• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.5 no.3
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• pp.127-137
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• 2012

In this paper, method using electric braking from stop area to high-speed area was presented in order to improve air-brake. And electric braking method can be improved environmental problems, efficiency, economy, etc. Method for electrical complete braking are two ways that method of inserting series resistance between the motor and the inverter, and method of inverter output voltage increase. In this paper, use series resistance insert method because economical and easy to apply. In addition, Series resistor is used short circuit method for reduce the power loss. In improved efficiency and the laboratory environment for secure braking, resistance insert method and inverter output voltage increase method showed same characteristics in all areas.

• Journal of Hydrogen and New Energy
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• v.34 no.3
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• pp.292-296
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• 2023

Until recently, ships, automobiles, and drones using hydrogen energy are being actively researched. In addition, stations and facilities for hydrogen supply are being developed widely. Among them, a hydrogen pump is necessary for compressing it and transfer to other stations. The liquid hydrogen pump is operated at very high pressure up to 90 MPa. In our research, a reciprocating plunger pump is studied. Especially, a leakage in a liquid hydrogen pump is predicted using a finite element method. As a result, it was found that leak mass flow rates changed from 0.09 to 2.20 kg/h, when the gaps were given from 2 to 6 ㎛. Thus pump efficiencies were calculated from 99.9 to 97.9%, when the gaps changed from 2 to 6 ㎛. These results are useful for the design of the liquid hydrogen pump.

• Journal of the Korean earth science society
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• v.23 no.8
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• pp.697-706
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• 2002

Authigenic siderite grains, ranging 100 to 250-${\mu}$m in diameter, are abundant in an about 8,600-year-old sediment layer in Namyang Bay, west coast of Korea. The siderites exhibit the aggregated spherulitic morphology with well-developed rhombs on the grain surfaces. They consist mostly of FeCO$_3$ (average, 65%) and MnCO$_3$ (average, 22%) with low Mg/Ca ratio (less than 0.4) in their bulk composition. A series of compositional ternary discrimination diagrams, together with high Mn and low Mg contents, show that only meteoric porewater was involved in siderite precipitation, assuming that depositional environment of host sediment is an organic-rich freshwater system. Considering a series of results such as radiocarbon age, authigenic Mn-rich siderite and lithological features, siderite-hosting sediment (unit Tl) is interpreted as freshwater swamp or bog deposition, infilling the topographic depressions that locally existed before the formation of mid-to-late Holocene tidal deposits. Center-to-margin compositional variation within individual grain is very systematic; Mn and Ca decrease towards the margin of a siderite grain, while Fe and Mg increase. It suggests that the spherulitic siderites were precipitated in this sedimentary layer in a series during the early diagenesis of MnOx-FeOx reduction under steady-state.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.3
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• pp.271-276
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• 1998

This experiment was carried out to investigate the changes on nutrient uptake and yields of onion when it was applied with urea and ammonium sulfate as nitrogen fertilizer types; potassium chloride and potasssium sulfate as potassium fertilizer types and lime requirement and phosphorus absorption coefficient controlled 5% as soil improvement index. The variety of onion used was CheonJuHwang and the soil used was Yonggye series in the Jeonnam Muan area. The amounts of N, P and K uptake were higher in the mixed application plot of ammonium sulfate and potassium sulfate than in the plot of urea or potassium chloride. The sulfate content of soil was higher in the period of plant growth than in the harvest stage. The sulfate content of plant was highest in the harvest stage and this content was higher in the stem and in the leaf than in the bulb. The sugar content of onion was 7.43~8.23 Brix content was higher in the large bulb than in the small bulb. The weight of dry matter and the rate of good quality were high in the mixed application plot of ammonium sulfate and potassium sulfate, so the yield of onion was increased 2~6% compared with control.

• Applied Biological Chemistry
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• v.41 no.6
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• pp.451-456
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• 1998

To find out the repeated application effect of chicken and pig manure composts on tomato growth and soil physico-chemical properties, different rates of the composts were applied to greenhouse soils with low fertility for 3 years and tomato was grown annually. As application rate of compost increased, the growth and fruit yield of tomato increased markedly, and there are also a little increase in sugar content in fruit juice and weight per fruit. When only compost was applied, however, physical and chemical properties in soil showed to be unbalanced such as significantly low bulk density and hardness, and high porosity as well as high organic matter and exchangeable K content, and low exchangeable Ca content than those of optimum range for soil diagnosis. Therefore mixed use of compost and chemical fertilizer is more promising way than the only use of compost to make suitable physico-chemical properties for tomato growth.

• Journal of the Korea Society for Simulation
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• v.23 no.4
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• pp.75-83
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• 2014

Most warship combat systems inquire human operator to control several sensor and another equipments as well as decision-modeling. For this reason, many researches with multi-agent based M&S (Modeling and Simulation) have been increasingly conducted. However there cannot find any researches of M&S based analysis for anti-submarine warfare that requires a high level of mission complexity between multiple platforms. In this research, we have been developed various combat platform models such as warship, submarine and helicopter, etc. In order to apply the multi-agent-based M&S technology to the anti-submarine warfare i.e. a HVU (High Value Unit) escort mission scenario. Then we have successfully analyzed the measures of effectiveness according to the different tactics and different situations. In future, the defence engineer maybe employ our methodology and tools to analyze actual tactical problem by simply inserting actual data into our agent model.

• Korean journal of food and cookery science
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• v.32 no.4
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• pp.426-432
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• 2016

Purpose: The consumption of noodles has increased domestically. However, noodles with high carbohydrate content can cause an increase in blood glucose compared with other foods. Therefore, in this study, Naengmyeon with high resistant starch was prepared for decreasing blood glucose by the addition of 0.5% citric acid (CN), 1% guar gum (GN) or 0.5% citric acid and 1% guar gum (CGN), and then it was incubated in a refrigerator for 3 days, and stored in a freezer for 1 month. Methods: The quality characteristics of these Naengmyeon noodles was evaluated based on total starch, resistant starch, water absorption, cooking loss, turbidity, in vitro starch hydrolysis, and in vivo glucose response. Results: There was no significant difference in the total starch, cooking loss, and turbidity. The resistant starch of GN (1.70%) and CGN (1.84%) was significantly increased when compared with that in Naengmyeon with no additives (N) and CN. In terms of water absorption, CN (86.01%) was the lowest in samples, followed by GN (92.17%), N (94.20%), and CGN (99.16%). CGN with high resistant starch was the lowest in in vitro starch hydrolysis in samples. However, it had no effect on the in vivo glucose response. In vitro starch hydrolysis exhibited a significant positive correlation (r=0.533; p<0.01) with in vivo glucose response. Conclusion: Therefore, future studies are needed to establish the standard for resistant starch contents in processed carbohydrate foods for delaying the increase in blood glucose. If this standard is established, it might help to develop processed foods for diabetic patients.

• Journal of Gifted/Talented Education
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• v.26 no.1
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• pp.101-122
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• 2016

The purpose of this study is to explore a possibility finding gifted underachievers who have high spatial ability, but low verbal ability in elementary science field. In Korea, because teachers used to refer students' academic achievement only when they recommend gifted students, underachievers used to be excluded. The participants are 5th-grade students in elementary school. In this research, developed teaching materials were given to students to find underachievers. Results of spatial ability test, verbal ability test, science academic achievement, non-verbal test, and interviews about light propagation concept were obtained. By analyzing results of this study, we found that spatial ability is the most important factors to understand light propagation. And there are some features to understand light propagation according to spatial ability. Lastly, this study shows the possibility of non-verbal test to find gifted underachievers with high spatial ability and low verbal ability.

• Journal of Life Science
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• v.16 no.7 s.80
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• pp.1119-1122
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• 2006

Ten species of Lycoris was selected for establishment of phylogenetic relationships using random amplified polymorphic DNA (RAPD) analysis, the native distribution and flowering characterestics. On the basis of the dendrogram constructed with the similarity coefficients, 10 Lycoris species were divided into two clusters. L. sprengeri and L. incannta were showed very high similarity in the RAPD analysis, same flowering time and flower color as pink. The leaf of L. squamigera. L. sanguinea, L. koreana, L. sprengeri and L. incanata emergenced in spring. The L. squamigera and L. sanguinea were showed high similarity in same cluster. Also L. koreana, L. sprengeri and L. incanata were showed high similarity in same cluster. The flower of L. radiata, L. radiata var pumila, L. albiflora and L. traubii was spider. These species was showed very low similarity in another Lycoris species.

• Journal of Society of Preventive Korean Medicine
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• v.1 no.1
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• pp.126-136
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• 1997

To procide basic data for improvement of oriental medical care system, the questionnaire interview was carried out with community peoples, over 20 years old, selected randomly in Seoul, Pusan, Taegu and Taejon err. from 10th Mar. to 20th Apr. 1996. The result were summarized as follows: 1. In the general characteristics of subjects, the highest portion of each part was 52.4% of male, 22.4% of thirties, 37.1% of college graduates, 19.1% of married, 30.6% of town dwellers, 63.3% of muddle social class, 26.6% of housewife, 19.3% of student, 16.6% officer and 11.6% of professional technician. 2. The portion of subjects agree to open oriental clinic in western medicine hospital was 60.0%, that of disagreement was 20.1%, Among 60.0% of agreement group, the high rate was showed in female, fifties, middle school graduates, unemployed, middle social level. 3. The rate of positive responses in system of a herb specialist was 64.7%, that of negative responses was 11.6%. Among positive responses, the groups of high rate were male. twenties, above college graduates, student, middle-high social level and city dwellers. 4. In the question whether a pack of herb medicine should be included in medical insurance or not, the rate of agreement was 74.3%, that of disagreement was 4.1%. Amount agreement subjects, the high rate was showed in male, young age, high educated, city dwellers, professional technician middle social class. 5. In the cost of oriental medical care, the portion was divided by 70.3% of expensiveness,25.6% of moderate, 4.1% of low price. among 70.3% of high price, the high rate was in female, forties, agrolivestock-fishery, and town dwellers. 6. In the question what the herb doctor should do for the improvement of oriental medicine, the highest rate was 54.2% in further study. The next was 23.0% in need of western medical and 9.1% in no complain in present situation. Among 54.2% of further study, the high rate was showed in male, forties, high school graduate, profession technician, high social level, christian, married and city dwellers. 7. About institution of oriental care, 86.8% of subjects answered to need of improvement, 8.0% of them replied no problem as present. Amount 86.8% of subjects, the high rate was showed in male, twenties, above college graduate, sales, singles, high social level and city dwellers. 8. About necessity of western medical care instrument in oriental medical hospital, the rate of sightly need was 47.5%, inevitably need was 37.7%, no need was 6.3%, the Positive subjects were showed high rate in male, officer, singer, the younger age, the higher educated, better social level and city dwellers. These results might be useful information for establishing of oriental medical care policies, which open oriental medical clinic in western medical hospital, equip western medical care instrument in oriental medical hospital, improve oriental medical care instrument carry out a herb specialist system, balance the resonable medical care cost and effort for further study & research on oriental medicine to satisfy increasing need of oriental medicine.