• Journal of Korean Electronics
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• v.27 no.2
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• pp.44-45
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• 2007

• Korean Journal of Food Science and Technology
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• v.43 no.4
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• pp.419-425
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• 2011

Changes in the flavor of muskmelons stored at different temperatures were examined to judge aroma patterns during storage. A mass-spectrometry based electric nose was used to distinguish the subtle differences in the muskmelon's volatile compounds. The data were used for a discriminant function analysis (DFA), and then the partial least square algorithm was used for a quantitative analysis. Volatile components in the muskmelons increased with storage, and the first discriminant function score (DF1: $r^2$=99.88%, F=3072.5) moved from a positive position to a negative position as the storage period increased. The proper point of maturity was anticipated as the $28^{th}$ day at 0$^{\circ}C$, $21^{st}C$ day at 4 and 7$^{\circ}C$, and $14^{th}$ day at 10$^{\circ}C$. Also, using the DF1 score we could predict the general tendency (vitamin C, stem moisture, acidity) of the muskmelons. The electronic nose revealed that the major volatile compounds that changed during storage of the melons were ethyl ethyl acetate, butyl acetate, nonanol, dodecanoic acid, hexadecanoic acid and tricosane. The amount of volatile compounds detected increased during storage.

• Food Science of Animal Resources
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• v.30 no.2
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• pp.313-320
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• 2010

The purpose of this study was to evaluate the freshness of chicken meat during 19 d of storage at $4^{\circ}C$ using a portable electronic nose. The portable system consisted of six different metal oxide sensors and a moisture sensor. Determination of volatile compounds with gas chromatography-mass spectrometry, total bacterial count (TBC), and 2-thiobarbituric acid reactive substances (TBARS) monitored the quality change of the samples. These results were compared with the results measured by the electronic nose system. TBC and TBARS measurements could be separated into five groups and seven groups, respectively, among ten groups. According to principal component analysis and linear discriminant analysis with the signals of the portable electronic nose, the sample groups could be clearly separated into eight groups and nine groups, respectively, among ten groups. The portable electronic nose demonstrated potential for evaluating freshness of stored chicken.

• Journal of Advanced Navigation Technology
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• v.26 no.3
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• pp.160-165
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• 2022

In this paper, we have proposed a magnetic resonant 6.78MHz WPT(wireless power transfer) technique which can be applied to a fixed transmitter and a receiver of varying relative distance and coil alignment, Power transmission characteristics are studied with the relative distance and misalignment ration of coil area between the transmitting and receiving coils. The coils are designed with the size of 60×80mm² by direct feeding method, and the characteristics are derived with the maximum relative distance of 50mm and horizontal area misalignment state of 0-40mm misalignment of coil center axis in the XY plane. The power transmission characteristics are compared between the 3D EM simulation and the measured data, and the power transmission shows larger than -3dB performance with the vertical distance of up to 30mm and 50% area misalignmment ratio. This work showsthe transmission characteristics according to relative distance and misalignment state between the cols and that direct feeding has advantage for the short relative distance and small misalignment ratio.

• Journal of Korean Electronics
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• v.5 no.5
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• pp.87-93
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• 1985

• 발명특허
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• v.18 no.1 s.203
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• pp.12-13
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• 1993

본회가 주최한 제 107회 발명 교실이 지난 1월 9일 발명장려관 연구실에서 개최됐다. 매월 둘째 토요일 오후 1시 30분에 개최되는 발명교실은 이 달에도 1백여 명이 참석하여 성황을 이루었다. 이날 발명교실에서는 코우드 전자 주식회사대표 정중석씨의 성공사례 발표에 이어 황종환 변리사의 $\ulcorner$산업 재산권제도$\lrcorner$에 이어 김관형 본회 상근이사의 $\ulcorner$발명의 창출과 사업$\lrcorner$에 대한 강의와 토론이 있었다. 발명가의 성공사례를 간추려 소개한다.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2001.07a
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• pp.239-245
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• 2001

• Journal of Welding and Joining
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• v.27 no.3
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• pp.1-3
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• 2009

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2019.10a
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• pp.201-201
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• 2019

• The Science & Technology
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• no.5 s.420
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• pp.42-45
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• 2004