• Journal of IKEEE
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• v.23 no.3
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• pp.751-755
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• 2019

This paper introduces a LED CUBE tool interacting with a distance sensor to solve real life problems in the physical computing field. Students can experience interactive education and intuitively understand the cubic operations with 3-dimensional animations obtained from a $3{\times}3{\times}3$ LED CUBE and a distance sensor connecting to Arduino. If the proposed LED CUBE is applied in physical computing section of the Information curriculum of middle school, students are expected to improve their computational thinking ability to solve problems in real life and other areas creatively and efficiently.

• Korean Journal of Optics and Photonics
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• v.26 no.1
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• pp.17-22
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• 2015

The applications for retro-reflectors, with their unique reflection characteristics, have been expanding, to include venetian blind slats, displays, traffic safety mark, etc. We propose expandable structures of inclined corner cube retro-reflectors and analyze their corresponding reflection characteristics. Various traffic safety structures with retro-reflectors may be designed more quantitatively using the chart of characteristics we have presented.

• Journal of Aerospace System Engineering
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• v.8 no.3
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• pp.27-33
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• 2014

The CubeSat, which was first launched to verify new technologies and for educational purposes, is now widely used as an educational tool since it makes possible development of manpower through practical training to produce the satellite at low development costs. At present, research and development on the CubSat is rapidly expanding in domestic and foreign universities. As one of the final 3 teams selected in the 2013 CUBE SATELLITE CONTEST organized by the Ministry of Science, ICT and Future Planning, Chosun University is also currently conducting R & D of STEP Cube Lab, which is a CubeSat scheduled to be launched in 2015 and whose main task is to verify space-based technologies in orbit. The present paper tries to present an overview of the CubeSat of Chosun University whose development is being led by its undergraduate students, and further, introduce the strengths of the present development program for developing space experts, based on the educational achievements from the R & D.

• Journal of Bio-Environment Control
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• v.31 no.1
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• pp.60-66
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• 2022

This study was conducted to investigate growth characteristics of paprika seedlings according to various qualities of LED light (red : blue = 10 : 0, red : blue = 8 : 2, red : blue = 2 : 8, white). Plant height and stem were significantly longer or thicker as red light ratio increased. Leaf area of paprika seedlings with red light was larger or no significant differences in a mixed light of red and blue. Dry weight of seedling was in the same with the result of leaf area. Seedlings with White light was significantly less than others in all characteristics. As red light ratio was increased, relative growth rate increased. As blue light ratio was increased, the net assimilation amount increased. Considering plant height, leaf area and production ability of dry matter per unit leaf area, the using mixed red and blue lights was suitable, especially at a mixed red : blue = 8 : 2.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2005.05a
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• pp.275-278
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• 2005

This study suggests experimental designs for interior products utilizing LEDs that are ideal for expressing diversity of light. It also attempts to develop various products by incorporating economic efficiency and diverse colors of LEDs into interior elements. LED door handles offer a range of 6-color LED lighting strips as a safety lighting system, while multi-function furniture (CUBE-scape) consists of LEDs with double-sided emitted lighting on completely transparent track structures. Both products are designed to make interior elements more user-friendly as they make most use of unique effects of LED such as light vibration and changes. Also the combination of plastic material-Technogel$^{\circledR}$, polypropylene, polycarbonate- maximize the LED lighting effect and diversify the designed item selection.

• Korean Journal of Optics and Photonics
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• v.30 no.4
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• pp.142-145
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• 2019

Normally, a corner cube retroreflector (CCRR) sheet is used as a retroreflective mirror array (RRMA) in a volumetric display. Each CCRR unit reflects light in the retroreflective direction, which is parallel to the incident light, and it makes a blurred image, as it shifts the position of light within its dimensions. Adopting a "curved planar wall" and "parabolic focusing" (x-axis), a hybrid-t(transverse direction)-RRMA is proposed, to improve the image quality and brightness. The improvement of image contrast is achieved by tuning a "linear v-shaped groove" structure to a "parabolic v-shaped groove". Also, the system has been simplified and the brightness enhanced 4 times by removing the half mirror.

• Proceedings of the Korean Society of Computer Information Conference
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• 2014.01a
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• pp.77-79
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• 2014

본 논문에서는 Arduino의 I2C 통신을 통해 인터랙티브한 악기를 제안한다. 각각의 큐브는 서로를 인식하고 인식 후 집단이 된 큐브들은 하나의 악기가 된다. Arduino의 통신 핀을 알루미늄 호일에 연결하여 다른 큐브와 접촉 시 통신이 될 수 있도록 하였다. 통신이 이룬 큐브들을 rgbLED 색상 변화를 통해 시각적으로 접촉/비접촉을 나타냈다. 또한 Processing을 통해 그룹이 된 큐브들의 악기 소리를 제어하였다.

• Wind and Structures
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• v.5 no.2_3_4
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• pp.177-192
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• 2002

Computation solutions for the flow around a cube, which were generated as part of the Computational Wind Engineering 2000 Conference Competition, are compared with full-scale measurements. The three solutions shown all use the RANS approach to predict mean flow fields. The major differences appear to be related to the use of the standard $k-{\varepsilon}$, the MMK $k-{\varepsilon}$ and the RNG $k-{\varepsilon}$ turbulence models. The inlet conditions chosen by the three modellers illustrate one of the dilemmas faced in computational wind engineering. While all modeller matched the inlet velocity profile to the full-scale profile, only one of the modellers chose to match the full-scale turbulence data. This approach led to a boundary layer that was not in equilibrium. The approach taken by the other modeller was to specify lower inlet turbulent kinetic energy level, which are more consistent with the turbulence models chosen and lead to a homogeneous boundary layer. For the $0^{\circ}$ case, wind normal to one face of the cube, it is shown that the RNG solution is closest to the full-scale data. This result appears to be associated with the RNG solution showing the correct flow separation and reattachment on the roof. The other solutions show either excessive separation (MMK) or no separation at all (K-E). For the $45^{\circ}$ case the three solutions are fairly similar. None of them correctly predicting the high suctions along the windward edges of the roof. In general the velocity components are more accurately predicted than the pressures. However in all cases the turbulence levels are poorly matched, with all of the solutions failing to match the high turbulence levels measured around the edges of separated flows. Although all of the computational solutions have deficiencies, the variability of results is shown to be similar to that which has been obtained with a similar comparative wind tunnel study. This suggests that the computational solutions are only slightly less reliable than the wind tunnel.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2002.05a
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• pp.184-186
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• 2002

The evolution of texture and microstructure during warm rolling and subsequent annealing in aluminium 3004 alloy sheet was investigated by X-ray texture measurements and microstructure observations. Warm rolling at 250$^{\circ}C$ led to the development of strong through thickness texture gradients with shear textures at the surface layer and a regular rolling texture in the center of the sheets. FEM simulations indicated that these texture gradients are caused by pronounced strain gradients throughout the sheet thickness. Upon recrystallization annealing, in the sheet center the characteristic cube-recrystallization texture developed, while in the surface layers with a pronounced shear texture continuous recrystallization took place which led to the formation of a very fine grained microstructure. It is concluded that the very complex strain history in the near-surface layers together with the resulting high work-hardening rate gave rise to the formation of the ultra-fine grains with an average size smaller than 2$\mu\textrm{m}$.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.8
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• pp.706-712
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• 2013

In this paper, channel modeling of VLC(Visible Light Communication) was investigated under indirect lightning circumstance which was the way that all phontons started from LED(Light Emitting Diode) were reached on the floor with NLOS paths. I supposed width(6m), depth(4m), height(2.2m) cube room circumstance for VLC communication channel and supposed that 4 LEDs were located at 2m height, which emitted photons at the direction of wall and ceiling. Channel characteristics, which were power attenuation and delayed receiving of light signal, were abstracted from receivers(PDs) which were located at 0.5m above from floor. The availability of channel was verified via BPSK based communication simulation.