• Korean Journal of Materials Research
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• v.14 no.9
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• pp.655-658
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• 2004

Lithium ferrites are a low-cost material which have been prominent in the high frequency core industry because of their excellent temperature performance and high squareness ratio. In order to develope the lithium ferrites with the high squareness and low coercive force, the ferrites of $Li_{0.48}Bi_{0.02}Ni_{0.04}Fe_{2.46-x}O_4$ were investigated the by varying composition, temperature and frequency. Electric loss of the Li-ferrite was lowered with the substitution of $Mn_{2}O_3$. The addition of $Mn_{2}O_3$ increased the magnetic induction (Bm&Br) but decreased the coercive force (Hc) and the squareness ratio (R=Br/Bm). Also, the Br value was stable at environmental temperature variation.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.8
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• pp.593-601
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• 2012

Ordered mesoporous oxide films have been focused because of their low density, high interior specific surface area, and high thermal insulation. Specially, the ordered mesoporous oxide films prepared by self-assembly has many advantages due to easy process and high reproducibility. In this work, ordered mesoporous $SiO_2$, $Al_2O_3$, and $TiO_2$ films were synthesized by control of composition and processing parameter. Also, their structural, thermal, and mechanical properties were characterized variously. In conclusion, ordered mesoporous oxides will be one of core materials in new technology due to their excellent and unique properties.

• Journal of Korean Society of Rural Planning
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• v.20 no.1
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• pp.175-188
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• 2014

This study is to achieve the slow-city planning based on resources in Cheongsong-gun. To this end, the natural landscape and old houses of the village set up potential of the core, and three complementary elements were traditional food and traditional crafts, nature trails. The vision and objectives were established, characterization plan by spacial areas was considered. The actionable items of the project by divisions such as; conservation and utilization of natural resources, old house villages, traditional crafts, traditional foods, landscape composition, social awareness training, to attract visitors, slow-city environmental policy, were proposed. And step-by-step implementation plan was proposed, Division of roles between public authorities and residents of the implementation process was considered.

• Journal of Korea Multimedia Society
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• v.19 no.6
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• pp.1065-1073
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• 2016

In this paper, we examined informatics textbooks for middle school students in accordance with 2009 revised curriculum through conducting both content analysis and surveys. The content analysis was analyzed the composition and contents of textbooks. Survey questionnaires were based on the authorization criteria and selection standards of informatics textbooks. The content analysis demonstrated that there were discrepancies among textbooks in areas such as the total number of pages, related material, the number of core concepts introduced in each chapter, and the application of software. The survey results showed that two sections - 'Expression and Modification' and 'Text' exhibited the most positive results, and the 'Creativity' section the least. Using the findings above, we present alternative ways to improve qualities of these textbooks.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.174-174
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• 2006

By condensing two different functional monomers, highly fluorescent aromatic polymers were prepared to produce a conjugated- conjugated spacer-type copolymer or conjugated-non-conjugated spacer-type copolymer. As synthesized polymers were soluble in an organic solvent and showed significantly enhanced optical properties compared to its monomer. Variation in the monomer composition afforded polymers having multifunctionaility such as photochromic-fluorescent polymers. Transparent thin films of the polymer as a solid medium were prepared using spin coating method and fabricated as a photoswitch, which showed photo-induced conductivity switching properties depending on the core monomeric unit in the polymers.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1346-1348
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• 2001

Generally, Invar alloy shows very low thermal expansion characteristics, lower than $2{\times}10^{-6}$/K approximately. To apply Fe-Ni-Co-C Invar alloy as a core material for large ampacity transmission line we studied the effects of magnetic properties on coefficient of thermal expansion. The coefficient of thermal expansion(CTE) suddenly decreases with addition of a little carbon(0.08%), increases with the increasing carbon and has a constant value at the composition over than 1.0%C. The trend of Curie temperature change with carbon is similar with that of CTE. Therefore, the CTE has a linear relationship with Curie temperature. However, the CTE linearly decreases with the ratio of saturation magnetization and Curie temperature(${\sigma}_s/T_c$).

• Journal of the Korean Ceramic Society
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• v.38 no.6
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• pp.506-508
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• 2001

The ferrite plating with applying power ultrasound waves of 19.5 kHz and 600W enabled us to encapsulate entirely MnZn ferrite cores for transformers with Ni$\sub$x/Zn$\sub$y/Fe$\sub$3-x-y/O$_4$coating. Supplying a NH$_4$OH solution during the plating broke the limit of the solubility of Ni ions to ferrite-plated films. The electrical resistivity of the NiZn ferrite coating increased with increasing the Ni and Zn content, reaching 2.3${\times}$10$\^$5/Ωcm at the composition of Ni$\sub$0.24/Zn$\sub$0.30/Fe$\sub$2.46/O$_4$. The saturation magnetization was 540 emu/㎤. As a result, the MnZn ferrite cores were successfully encapsulated with the NiZn ferrite coatings for an insulation layer.

• Preventive Nutrition and Food Science
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• v.16 no.4
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• pp.370-375
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• 2011

The antioxidative activity and the polyphenolic composition were examined in four different cultivars of apple (Malus domestica), 'Fuji', 'Tsugaru', 'Hongro' and 'Kogetsu', and their parts (peel, core, pulp and juice). The total phenolics, flavonoids and anthocyanins differed among the tested cultivars and parts. Peel parts had the highest total phenolics and anthocyanin content. Contributions of those phenolics to total antioxidative activity were determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging assays, and the linoleic acid oxidation assay. Concentration of phenolics contributes significantly to the total antioxidative activity of apples. Clearly, apple peels, especially from Hongros and Kogetsus, possess high levels of phenolic compounds and antioxidants. Therefore, apple peels may potentially function as a value-added ingredient.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.3
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• pp.105-110
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• 2014

Feature-oriented software product line engineering is to develop various products by developing product line core assets in terms of features and composing those features. However, the developed product may not behave correctly if the feature interaction problem has not be properly taken into account during the feature composition. This paper proposes techniques for identifying and modularizing undesirable feature interactions effectively. The scientific calculator product line is used for evaluating the applicability of the proposed method.

• Journal of the Korean Vacuum Society
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• v.12 no.S1
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• pp.17-20
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• 2003

We have studied magnetic and structural properties of ultrathin Ni films grown on PI(lII) surface using in situ surface magneto-optic Kerr effect and X-ray photoelectron spectroscopy. Perpendicular magnetic anisotropy was absent, and longitudinal Kerr signal was only detectable for Ni films thicker than 6 monolayers. Enhancement in longitudinal Kerr signal by 30% was achieved by post-annealing at temperatures below 800K, but upon annealing at 820K, surface alloy was formed. By using core-level binding-energy shifts, the composition was determined to be Ni 70 at. %.