• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.3
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• pp.478-486
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• 1998

$CaTiO_3-x(La_{1/3}Nd_{1/3}TiO_3\;(0\le \textrm x\le0.8)$ system was prepared by reaction of $CaCO_3,\;LaO_3,\;Nd_2CO_3$ and ,TEX>$TiO_2$ mixture at 1673 K, which can be applied for microwave dielectric ceramic materials. The lattice parameters of(1-x))$CaTiO_3-x(La_{1/3}Nd_{1/3}TiO_3\;(0\le \textrm x\le0.8)$ system increased with the increase of x. Its structure was investigated by Rietveld profile-analysis of XRD in detail. Cations $ La^{3+}$ and Nd^{3+}$ were located at the $Ca^{2+}$ site in the range of $0\le \textrm x\le0.8$. crystal structure in $;(0\le \textrm x\le0.6)$ maintained space group Pnma with CaTiO_3 structure. The tiled and distorted $TiO_6$ was gradually released with the increase of x in $0\le \textrm x\le0.6$ .The structure was changed to a new space group of $Pmn2_1$ at the x value of 0.8. The relative dielectric constant $(\epsilon_r)$ of $(1-x)CaTiO_3-x(La_{1/3} Nd_{1/3})TiO_3$ ($(0\le \textrm x\le0.8)$) system was exponentially decreased by with the increased of x. The temperature coefficient of resonant frequency $(\tau_f)$ decreased with the increase of x in $0\le \textrm x\le0.6$ and then increased again at x=0.8 due to the change of crystal structure. The value of Q$\cdot f_o$ was 13800 (GHz) at x=0.2 and was very low under 2000 (GHz) in 0.4$\leq$x$\leq$0.8.

• Archives of design research
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• v.17 no.3
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• pp.221-230
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• 2004

Design textbooks for general education bring our attention to the education of design as a part of whole education. In this vein, this thesis tried to analyze and discuss on the current status of design education contents included in the 7th educational curriculum of the Art & Life. This study had a historical review of the contents of arts education as well as a review of theoretical contents in art education. Also this thesis analyzed five types of Art & Life text books currently used at high schools with weight given to the design and to the status of pictorial coverage in the text books. Finally, the thesis presented problems of design education through a comparative analysis of high school arts education and design education. Through the analysis, inequality of design contents in education was reported. It was clearly attributable to the backgrounds of text book writers. For example, authors with graphic design backgrounds tended to lack product and environment design concepts, while hand craft section of text books all showed a biased contents towards traditional Korean arts. In the analysis of pictorial coverage, similar to the composition of academic contents, coverage was concentrated in the graphic design areas; inequality in quantity of pictures found with a ratio of 1 to 4. In terms of areas of arts, design contents in text books were concentrated only in arts creation chapters among the 3 major areas of arts appreciation, understanding, and creation. Design education is attained in an atmosphere of creativity and the provision of ample teaching material. It is because diverse contents will generate the development of arts. When compared to design education curriculum of U.S. and Japan, these creativity put their focus of design education in the understanding and emotional contacts, so that every application is easily attained. In terms of expression learning, creativity and diversity of material are emphasized. From Kindergarten to middle, and high school periods, apparently the care contents of deign is emphasized. A textbook in the 7th education curriculum is one of the sources for education. In designing text books, learning process should be emphasized following subjects and natures of arts so that creativity can be achieved. Therefore, a systematic approach for design research and educational development for material would be needed in textbook design.