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서영호;조영호
- The Transactions of the Korean Institute of Electrical Engineers C
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- v.53 no.4
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- pp.218-224
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- 2004
We present a miniature Direct Methanol Fuel Cell (micro-DMFC) using platinum sputtered microcolumn electrodes with a limited amount of fuel. We use the microcolumn electrode in order to improve the power density of the micro-DMFC that consists of two electrodes and polymer electrolyte. We also design the built-in fuel chamber in the anode for the portable electronics applications. We design and fabricate both microcolumn and planar electrodes, having an identical projective area of 5mm${\times}$5mm. The diffusion current density of the microcolumn electrode is 1.73 times higher than that of the planar electrode at electrode potential of 1.1V in the half-cell test. The micro-DMFC based on the microcolumn electrodes shows the maximum power of 10.8$\pm$7.54㎼(43.23$\pm$0.16㎼/$\textrm{cm}^2$) at the projective area of 5mm${\times}$5mm, while the planar electrode micro-DMFC shows the maximum power of 0.81$\pm$0.42㎼(3.24$\pm$1.68㎼/$\textrm{cm}^2$) at the same projective area. The micro-DMFC based on the microcolumn electrodes shows 13 times higher power density that the micro-DMFC based on the planar electrodes does.
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Han, Kyeong-Hye
- Journal for History of Mathematics
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- v.18 no.4
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- pp.29-38
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- 2005
This Paper discusses the history of the conflicts between synthesis and analysis, from those in heuristic and logic development style in ancient Greek to those in projective geometric methods. The two methods, which originally displayed difference in heuristic, offer the base for the two fields of geometry, the analytic geometry and the synthetic geometry in the 18th century as they originated from the field of geometry. As to the 19th century, they even display antagonistic aspects derived by having other perspectives about the true nature of mathematic but finally lose the reason of conflict as the ancient times when the dialectical sublation of both had been proposed.
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Lee, Seung-Jae
- Journal of the Architectural Institute of Korea Planning & Design
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- v.36 no.3
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- pp.39-47
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- 2020
This study is preliminary and qualitative research to find out the possibility of using children's architectural work as projective test tools. The features of 21 works from the activity of built-environment education for children was analyzed and compared with MBTI psychological preference types. The key results are as follows: 1) Observation and communication was required to understand and analyze children's architectural works. 2) The results of children's work appeared in various ways, and were classified as indicators according to composition, shape, expression, program, circulation. These indicators also showed the independence of personal expression types regardless of age or gender. 3) The comparison between architectural expressions and MBTI preference types revealed a significant relationship between the indicators. The relationship only appeared in certain indicator pairs. Therefore, it can be said that the built-environment education could be used as a projection test tool to understand the psychological preferences of children. In conclusion, the meanings and limitations of this study and the possibility of future researches were discussed.
https://doi.org/10.5659/JAIK_PD.2020.36.3.39 인용