• Journal of Bio-Environment Control
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• v.23 no.4
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• pp.383-390
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• 2014

This study was conducted to investigate the growth characteristics of cucumber scion and pumpkin rootstock under different levels of light intensity (photosynthetic photon flux, PPF) and plug cell size in a closed transplant production system with artificial lighting. Cucumber scion and pumpkin rootstock seedlings were grown under the combinations of three levels of PPF (PPF 165, 248, and $313{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) and five types of plug tray (50, 72, 105, 128, and 200 cells in the tray) for nine days. The shoot dry weight and relative growth rate increased with increasing PPF and plug cell size. As PPF increased, cucumber scion and pumpkin rootstock seedlings had higher dry matter, lower specific leaf area, and lower hypocotyl length. The first true leaf of cucumber scion and pumpkin rootstock unfolded at eight and seven days after sowing, respectively, except the treatment using 200-cell plug tray. The unfolding of first true leaf of seedlings grown in 200-cell plug tray was delayed by one day. Accordingly, it was considered that the use of small cell size such as 200-cell plug tray would require more time for the production of scion and rootstock. Based on the results, we suggest that cucumber scion and pumpkin rootstock be grown in 105-cell to 128-cell plug tray for eight days and 72-cell to 105-cell plug tray for seven days, respectively, when using splice grafting method with root-removed rootstock. Additionally, higher PPF is suggested to improve the growth and quality of scion and rootstock.

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.35.1-35.1
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• 2005

• Proceedings of the Plant Resources Society of Korea Conference
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• 2007.11a
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• pp.350.1-350.1
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• 2007

• Proceedings of the Plant Resources Society of Korea Conference
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• 2007.11a
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• pp.350.2-350.2
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• 2007

• Proceedings of the Plant Resources Society of Korea Conference
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• 2007.11a
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• pp.351.1-351.1
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• 2007

• Journal of Bio-Environment Control
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• v.28 no.4
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• pp.358-365
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• 2019

This study was conducted to estimate the dimensions of horticultural products and the mean plant height of plug seedlings using three-dimensional (3D) images. Two types of camera, a ToF camera and a stereo-vision camera, were used to acquire 3D images for horticultural products and plug seedlings. The errors calculated from the ToF images for dimensions of horticultural products and mean height of plug seedlings were lower than those predicted from stereo-vision images. A new indicator was defined for determining the mean plant height of plug seedlings. Except for watermelon with tap, the errors of circumference and height of horticultural products were 0.0-3.0% and 0.0-4.7%, respectively. Also, the error of mean plant height for plug seedlings was 0.0-5.5%. The results revealed that 3D images can be utilized to estimate accurately the dimensions of horticultural products and the plant height of plug seedlings. Moreover, our method is potentially applicable for segmenting objects and for removing outliers from the point cloud data based on the 3D images of horticultural crops.

• Journal of Energy Engineering
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• v.19 no.2
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• pp.81-91
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• 2010

Plug-in hybrid electric vehicles(PHEVs) are gaining attention over the world due to their abilities to reduce $CO_2$ emission and gasoline/diesel consumption by using electricity from the grid. Lithium ion battery is one of the most suitable candidates as energy storage device for PHEVs applications up to 2030. This review focuses on the present status of lithium ion battery technology, then on comparison of the performance characteristics of the promising cathode materials.

• Journal of The Korean Association of Information Education
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• v.20 no.1
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• pp.13-20
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• 2016

Data are numbers and texts, images, sound etc in real world. But, data is represented as a sequence of 1s and 0s in computer. It is very difficult that elementary students understand the concept of data representation through traditional lecture method. In this paper, we analyzed the software education curriculum of KAIE and selected contents of data representation education for the mid-grade elementary students. Also, we developed teaching- learning materials and multimedia contents for data representation education. The method proposed in this paper is expected to contribute to software education for data representation education.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.10
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• pp.2171-2176
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• 2012

PCs and its peripherals uses more power in standby mode even if they are not actually being used. In particular, PCs and its peripherals used in school and office, plugged in at all times during working hours, but not used much time, even if turned off consume a portion of the power. In this paper, we developed Networked Smart Plug for Power Management of PC & Peripherals which is consist of EMS, Smart Plug, PC Agent and Smart Phone App. for power saving of PC and a variety of peripheral devices in office or home, and evaluated the performance of the system.

• Journal of The Korean Association of Information Education
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• v.13 no.4
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• pp.479-487
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• 2009

In the existing curriculum of the Elementary computer Education emphasizes students' problem-solving ability and knowledge of informatics. However, current computer education focus on using application program. In order to raise students' problem-solving ability and logical thinking ability, it is necessary to learning about computer science education. Thereupon, this study applied unplugged learning method to the elementary student. To apply the play-based unplugged learning method to the area of information representation. As a result, unplugged learning method produced higher academic achievement than the lecture model. Also it was more positive in the affective area than the lecture model.