• Journal of Advanced Marine Engineering and Technology
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• v.35 no.6
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• pp.829-834
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• 2011

This paper introduces a new system which measures abrasion quantity of cylinder liners of large-scale marine diesel engines. The proposed system consists of three parts; measurement part where an LVDT, a temperature sensor, a camera and LED for lighting control are installed, monitoring part which accomplishes measurement command transmission and monitoring based on PC or notebook, and master control part which controls the measurement part and transfers measurement data to the monitoring part. The accuracy of the developed system is compared with that of an internal micrometer with 1/100 mm accuracy.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.3
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• pp.147-153
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• 2014

In this paper, we propose smart emotional lighting control system based on the android platform. The proposed smart emotional lighting control system be configure android platform and sensibility lighting equipment, expansion device, zigbee module. Smart emotional lighting control system based on the android platform is automatic control possible using the illumination sensor, and by selecting the desired lighting partial control can be designed. The experimental results of the proposed smart emotional lighting control sensitivity than conventional lighting control system decreased the power consumption and efficient lighting control was possible. Office acts will be suitable conditions to control the color and brightness, so they can be controlled from the improves concentration and ability to work.

• Journal of Broadcast Engineering
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• v.21 no.5
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• pp.816-823
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• 2016

This paper studies a light emitting diode(LED) overlapping method of a head-up display that consists of a digital micro device(DMD) panel and a red, green, blue LED in order to increase the brightness of display system and optical output power. This optimization overlapping method removes a quantization noise which occur due to LED overlapping too excessive and stabilizes the junction temperature of LED. In order to reduce junction temperature of LED, the a correlation between a green duty and LED overlapping ratio is studied. Throughout this study, the brightness of head-up display exhibited high increasement ratio of luminance around 33.3 percent at 39 percent overlapping method.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.10
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• pp.16-26
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• 2012

This study conducted a subjective evaluation of brightness perception and visual discomfort according to dimming speeds and CCTs(Correlated Color Temperatures). Dimming speeds of two different CCT lights(2,700K, 6400K) were set to 1.7%/s, 3.3%/s, 5.0%/s, 6.7%/s, and 10.0%/s respectively. Subjects checked the time when they perceived the change of the brightness and visual discomfort. As a result, when dimming speeds were 1.7%/s, 3.3%/s, 5.0%/s, 6.7%/s, more than half of subjects responded the change of the brightness in 55.0~45.0% dimming ratios, and felt the visual discomfort in 35~25% dimming ratios. When the brightness was changed, dimming level responded to the brightness perception of hight CCT(6,400K) was higher about 8.0% then dimming level responded to the brightness perception of low CCT(2,700K). Dimming level responded to the visual discomfort of low CCT(2,700K) was higher about 5.0% then dimming level responded to the visual discomfort of hight CCT(6,400K).

• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.6
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• pp.618-625
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• 2005

This paper has achieved that an optimal design and experiments of heater and cathode of electron gun that serve to embody high current density in CRT display. For the high brightness, high resolution and larger size in CRT display, high current density of electron gun is indispensible. An Impregnation style cathode is used, and must heighten operating temperature of heater to get high current density for this, it is proportional hereupon and power dissipation increases. In this paper, to get low power cathode with high current density, There are produced and tested sample that differ lead type of heater, coating method, the pitch and number of winding of the first and second coiling in the heat emission area for the low power design of high current density cathode heater in this paper.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.35 no.1
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• pp.99-106
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• 2019

This study aims to recommend the proper Color rendering index (CRI), the Correlated Color Temperature (CCT), and illuminance levels of Light-Emitting Diode (LED) lighting based on the analysis of the criteria of the current CRI, the CCT, and illuminance levels in merchandising spaces with LED lighting conditions. It would be a basic material to apply in line with user preference for LED merchandising lighting. To this end, it examines relevant literature review on the experiments designed to test whether lighting characteristics affect brightness perception, color appearance, and pleasantness. Highly saturated colors appear brighter than low saturated colors. Two lighting applications - grocery and clothing shop - were created in elaborating the effect of LED lighting characteristics of CRI on color appearance and the CCT and illuminance on pleasantness. The findings show that the criteria of CIE Ra<80 are appropriate to provide better color appearance of illuminated products in terms of LED lighting that can enhance color saturation, particularly for the red color. Furthermore, 2700 K and less than 500 lux for grocery, 4000 K and more than 500 lux for clothing shop are found to be the proper the CCT and illuminance levels respectively to bring better preference under LED lighting.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.2
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• pp.46.1-46.1
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• 2021

태양으로부터 3Rs보다 높은 코로나 밝기의 대부분은 먼지에 의해 산란된 F코로나로부터 나온다. F코로나와 자유전자의 톰슨산란에 의한 K코로나를 분리하는 효과적인 방법은 편광을 이용하는 것으로 알려져 있고 현재 NASA와 천문연간 협력개발 중인 K코로나 관측 기기 COronal Diagnostic EXperiment(CODEX)도 편광을 이용한 분류를 기본으로 자유전자의 온도와 속도를 측정한다. 문제는 F코로나도 약간의 편광도를 가져서 K코로나와 구별이 불가능해지는데다 F코로나의 편광량은 먼지입자의 구성물질, 모양, 산란 위치 등에 따라 달라서 거의 예측이 불가능하고 지금까지 제대로 알려진 바도, 연구된 바도 없다. 우리는 CODEX에서 F코로나 편광량을 산출하기 위해 한 개의 협대역 필터(Narrow Bandpass Filter)를 추가장착하는 것을 제안하였고 그 중심파장과 밴드폭을 결정하였다. 몬테카를로 계산 결과 10장의 393.55nm 중심의 1.4nm폭 협대역필터와 393.5nm 중심의 10nm 협대역 필터비를 이용해 1Rs 화소의 해상도로 F코로나 편광량을 결정할 수 있을 것으로 예상된다. 2023년 CODEX 발사 후 본 관측이 성공적으로 수행된다면 F코로나의 편광량의 시간, 공간적 변화를 확인할 수 있으며 추가적으로 K코로나를 보다 정밀하게 분리해낼 수 있을 것으로 기대된다.

• Journal of the Korean earth science society
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• v.26 no.3
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• pp.283-296
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• 2005

The effect of ozone and surface temperature on the ozone band at $9.7{\mu}m$ has been investigated from radiative transfer theory together with observations in order to derive empirical methods for remotely sensing ground-ozone concentration. Simultaneous observations of satellite (MODIS Aqua; ECT 13:30) and ground-ozone at 79 stations have been used over the Seoul Metropolitan Area (SMA; 125.7-127.2 E, 37.2-37.7 N) during four ozone-warning days in the year 2003. Cloud effect on the band in the methods was filtered out based on synoptic observations. Upwelling radiance values at $9.6{\mu}m$ which have been estimated at the given ozone concentration of 327-391 DU depend on surface temperature (Ts) showing $5.52\~5.78Wm^{-2}sr^{-1}\;at\;Ts = 290 K,\;and\;9.00\~9.57Wm^{-2}sr^{-1}$ Ts = 325K. Thus, the partitioned contributions of ozone and temperature to intensity of ozone absorption band are $0.26Wm^{-1}sr^{-1}/64\;DU\;and\;0.31 Wm^{-2}sr^{-1}/35K$, respectively. Here the intensity which has been used to remotely detect ground-ozone concentration from infrared satellite measurement is defined as the difference in brightness temperature between $11{\mu} m\;and\;9.7{\mu}m (i.e.,\; T_{11-9.7})$. The methods in this study have been applied to estimate ground-ozone from MODIS data in cases that there are significant correlations between the band intensity and ground-ozone. The values of estimated ozone significantly correlate (0.49-0.63) with ground observations at a significance level of $1\%$. For the improved methods, further study may be required to use tropospheric ozone rather than ground-ozone, considering the variation stratospheric ozone.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.72-77
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• 2017

Lighting systems in modern society has been developed using a combination of IT technology and LED lighting for the purpose of bringing about changes in human-centered natural lighting and to take advantage of the efficient management and energy saving of LED lighting. In this paper, we propose an LED lighting control system that can control the color temperature and brightness of LED lighting composed of 3000K Warm LEDs and 6000K Cool LEDs by using an Arduino Due and wireless communication technology such as Bluetooth and Zigbee. The Arduino Due allows the color temperature of the lighting to be adjusted in several steps by controlling the duty rate and enables many lights to be controlled using Zigbee communication capable of 1: N multiple communication. By using Bluetooth communication, it is possible to easily control the LED lighting by means of a smartphone application, thereby enhancing the convenience for the user. The wireless communication based LED lighting control system implemented in this study cannot only provide human-centered lighting through its color temperature control from 3067K to 5960K and illumination control, but can also reduce the power consumption and be used as a natural-friendly lighting system.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.3
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• pp.342-347
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• 2007

Physicochemical properties of onion powder as influenced by drying methods were investigated. Moisture contents of onion powder were 13.29%, 12.99%, and 10.78% for samples dried using hot-air dryer, freeze dryer, and vacuum dryer, respectively. There were no significant differences in crude fat, crude protein, and crude ash content (p>0.05) depending on the drying methods. Samples prepared by freeze drying showed a significantly higher L-value as compared with those prepared by hot-air and vacuum drying (p<0.05). Scanning electron micrographs showed that freeze drying produced smaller particle-sized sample which in turn resulted in the higher porosity of the sample. Freeze dried samples revealed significantly lower degree of rehydration than other samples (p<0.05) probably due to small particle size of the sample. Water solubility of freeze dried sample appeared to be higher than that of other drying methods while the swelling ratio of the same sample appeared to be lower than that of the others. Browning index was significantly lower in samples prepared by freeze drying (p<0.05) but not significantly different between samples dried by hot-air and vacuum drying. Vitamin C content was higher in freeze dried onion powder due to the lower temperature applied to the sample. Freeze dried onion powder contained significantly lower amount of total polyphenol and higher amount of total sugar as compared to other samples (p<0.05).