• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.04a
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• pp.88-95
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• 2002

Recent development in the field of RE-Ba-Cu-O (REBCO, RE: Y or rare earth elements) bulk high-Tc superconductors (HTS) is reviewed in the present paper. After the fatal weak link problem of sintered REBCO superconductors has been overcome by melt processing, this field has been greatly advanced during last ten years. The critical current density $J_c$ at 77 K has been enhanced by introducing effective flux pinning sites into the $REBa_2Cu_3O_y$ (RE123) superconducting matrix. Large melt-textured REBCO bulk crystals have been fabricated with the TSMG(top-seeded melt growth) technique. Mechanical properties of REBCO bulks have been improved by using the Ag additive or epoxy resin. Real bulk applications such as current lead, fault current limiter, flywheel energy storage system, magnetic field source, magnetic separation system, and etc., surely come true near future.

• The Korean Journal of Community Living Science
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• v.27 no.1
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• pp.67-81
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• 2016

Responsible tourism has become an established area of the tourism industry. This study aims to identify the factors that influence re-participation in responsible tourism in rural Korea. On-site survey was conducted on 436 tourists by seven responsible tourism agencies in Korea. The motivation for responsible tourists was categorized into seven types: family togetherness, escape and relaxation, personal growth, social interaction, various experiences, learning, and natural experience. The estimation of a binary logistic regression model determined the characteristics of responsible tourists who are most likely to opt for re-participation in responsible tourism. Results indicated that important factors for re-participation in responsible tourism were 'age', 'educational level', 'accompany', 'length of stay', and 'motivation'. The results implied that tourists' internal and external factors are important for re-participation in responsible tourism. It is expected that this study will contribute to the market expansion of responsible tourism.

• Journal of Information Technology Services
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• v.8 no.1
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• pp.99-111
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• 2009

Rapid growth of Management Information System (MIS) and evolution of software system enlarge maintenance necessity and it needs a process to implement information system service in business. This paper proposes service-oriented maintenance process of component software based on service design and implementation provided by existing processes for maintenance, MaRMI-RE and ITIL. The proposed process derives activities and tasks of the process by identifying services according to service guidelines. Service-oriented maintenance process is produced by analyzing correlation between the derived activities and tasks and MaRMI-RE's and adding the tasks to MaRMI-RE. To verify availability of the proposed service-oriented maintenance process, correlation between artifacts is proved.

• Natural Product Sciences
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• v.10 no.3
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• pp.134-139
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• 2004

In this study, an immunoactivity of panaxtriol ginsenosides Re and Rg1 against infection due to Candida albicans was investigated. The ginsenosides were extracted from Red Ginseng with 85% ethanol and heat-treatment and were analyzed by HPLC on water-acetonitrile as a mobile phase. The HPLC analysis revealed that the extract contained ginsenosides Re and Rg1, which were eluted as a combined peak. By agar diffusion susceptibility, the mixture of Re and Rg1 had no growth-inhibitory activity on C. albicans yeast cells. However, in animal tests BALB/c mice given the mixture of Re and Rg1 intraperitoneally (Lp.) before intravenous (Lv.) infection with live C. albicans yeast cells had longer mean survival times (MST) than MST of control mice groups that received only buffer solution instead of Re and Rg1. In experiments 60% of the ginsenosides-treated mice survived the entire duration of the 50-day observation. The Re and Rg1 mixture induced production of nitric oxide when interacted with RAW 264.7 macrophage cell line. In addition, the mixture caused morphological change of the macrophages. These data indicate that immunostimulation by the Re and Rg1 may be responsible for the protection of mice against disseminated candidiasis.

• Korean Journal of Poultry Science
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• v.34 no.1
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• pp.23-29
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• 2007

Rare earth(RE) is a common name indicating 17 of specific elements including 15 of lanthanides, scandium (Sc), and yttrium(Y). This study was conducted to compare the effect of RE to growth stimulating antibiotic products in broiler diet. One of the products commonly used in broiler feeding, Chlorotetracycline(CTC) was used at a level of 200ppm for the antibiotic treatment and replaced by 100ppm RE for the RE treatment. Dietary addition of RE and CTC showed similar effects in improving broiler growth and feed conversion each other, and those were significantly better when compared to those of the control group(P<0.05). Abdominal fats of chicks fed RE were significantly lower than others(P<0.05). Intestinal E. coli and total microbial numbers were reduced by RE addition(P<0.05), but the number of Lactobacillus was not affected. The number of Salmonella was also decreased but it was not significant.

• Journal of The Korean Society of Grassland and Forage Science
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• v.23 no.1
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• pp.43-48
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• 2003

The effect of rare earth(RE) at three difference levels of nitrogen on the growth and nitrate content of chicory (Cichorium intybus L.) were studied in terms of leaf size, fresh and dry weight increase, and chlorophyll and nitrate content grown in plastic pots within glasshouse. Leaf size was enlarged as the level of nitrogen applied was high, and leaf within, length, and thickness of leaf were increased by RE treatment showing significant difference at high nitrogen(N+1) plot. As the level of nitrogen applied was high, as fresh and dry weight per plant was increased significantly(p<0.05), and sprinkling cabbage with RE increased fresh and dry matter yield to 2∼12, 4∼6.2% more, respectively. Dry matter content of Chinese cabbage was increased by RE sprinkling. At all levels of nitrogen fertilized chlorophyll contents were increased by RE treatment. As the level of nitrogen was high, as the content of chlorophyll was highly increased by RE. Nitrate was accumulated more at high level of nitrogen application, but nitrate was decreased by RE application, 40% decrease at very high nitrogen plot(N+2). RE stimulated the growth of chicory with high chlorophyll content, and showed the possibility producing high quality agricultural products low in nitrate content.

• Nuclear Engineering and Technology
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• v.54 no.8
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• pp.2801-2808
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• 2022

The synergistic effect of ZrC nanoparticle pining and Re solution in W matrix on the thermal stability of tungsten was studied by investigating the evolution of the microstructure, hardness and tensile properties after annealing in a temperature range of 1000-1700 ℃. The results of metallography, electron backscatter diffraction pattern and Vickers micro-hardness indicate that the rolled W-1wt%Re-0.5 wt% ZrC alloy has a higher recrystallization temperature (1600 ℃-1700 ℃) than that of the rolled pure W (1200 ℃), W-0.5 wt%ZrC (1300 ℃), W-0.5 wt%HfC (1400-1500 ℃) and W-K-3wt%Re alloy fabricated by the same technology. The molecular dynamics simulation results indicated that solution Re atoms in W matrix can slow down the self-diffusion of W atoms and form dragging effect to delay the growth of W grain, moreover, the diffusion coefficient decrease with increasing Re content. In addition, the ZrC nanoparticles can pin the grain boundaries and dislocations effectively, preventing the recrystallization. Therefore, synergistic effect of solid solution Re element and dispersed ZrC nanoparticles significantly increase recrystallization temperature.

• Journal of Ginseng Research
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• v.27 no.4
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• pp.178-182
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• 2003

Vesicular-arbuscular mycorrhizae (VAM) fungi naturally colonise American ginseng roots and this relationship is highly beneficial to enhance plant productivity. Our goal was to determine the effect of adding two Glomus species (Glomus etuticatum, G. intraradices) on survival, photosynthetic capacity, growth, morphology and root ginsenoside content of one-year-old American ginseng plants grown in a broadleaf forest. While our study revealed that VAM inoculations significantly affected root morphology and Re ginsenoside content, the survival, photosynthetic capacity and root growth of American ginseng plants were not significantly influenced by VAM inoculations. Surface area and volume of rootlets were 16-25% higher for ginseng grown in VAM-inoculated soil compared to those grown in the control plots. Also, Re ginsenoside content was 18 ％ higher in YAM-inoculated roots compared to controls.

• IE interfaces
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• v.16 no.1
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• pp.103-110
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• 2003

Growth curves are widely used in forecasting the market demand. When there are only a few data points available, the estimated model parameters have a low confidence. In this case, if some expert opinions are available, it would be better for predicting future demand to adjust the model parameters using these information. This paper proposes the methodology for re-estimation of model parameters in growth curves when adjusting market potential and/or time of maximum sales. We also provide the detailed procedures for five growth curves including Bass, Logistic, Gompertz, Weibull and Cumulative Lognormal models. Applications to real data are also included.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.1 no.1
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• pp.5-16
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• 1991

It was grown Cubic $ZrO_2(10 mol% Y_2O_3)$ single crystals doped with 1 wt% rare earth metal oxides (RE=Ce, Pr, Nd, Eu, Er) by Skull method. It was investigated electrical properties on (111) plane of grown single crystals by Impedance Spectroscopy. It was potted relation between temperature and electrical conductivities and observed the transition at $약300-400^{\circ}$ It was obtained activation energy on the migration of oxygen vacancy between low temperature (before the transition) and high temperature (after the transition till ${\11}500^{\circ}$) and its difference can be seen the activation energy of the formation of oxygen vacancies by break up defect complexes. It was obtained the activation energy according as add yttria and rare earth metal oxides and discussed ionic conduction mechanism. Grown single crystals showed Ce: orange - red, Pr: golden - yellow, Nd: lilac, Eu: light pink, Er: pink due to dopant effect from the light absorption data in the visible range.