• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.9-9
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• 2010

In this paper, High Brightness LED driver IC using new current sensing circuit is proposed. This LED driver IC can provide a constant current with high current precision over a wide input voltage range. The proposed current-sensing circuit is composed of a cascode current sensor and a current comparator with only one reference voltage. This IC minimizes the voltage stress of the MOSFET from the maximum input voltage and has low power consumption and chip area by using simple-structured comparator and minimum bias current. The LED current ripple of the designed IC is in ${\pm}5%$ and a tolerance of the average LED current is lower than 2.43%. This shows much improved feature than the previous method. Also, protections for input voltage and operating temperature are designed to improve the reliability of the designed IC. Designed LED driver IC uses $1{\mu}m$ X-Fab. BiCMOS process parameters and electrical characteristics and functioning are verified by spectre(Cadence) simulation.

• Nuclear Engineering and Technology
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• 제37권5호
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• pp.433-446
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• 2005

The development of accelerator science and technology has been accommodating ever increasing demand from scientific community of the beam energy and intensity of proton beams. The use of high-powered proton beams has extended from the traditional application of nuclear and high-energy physics to other applications, including spallation neutron source replacing nuclear reactor, nuclear actinide transmutation, energy amplification reactors. This article attempts to review development of proton accelerator, both linear and circular, and issues related to the proton beam energy, intensity as well as its output power. For related accelerator physics and technical review, one should refer to the recent article in the Reviews of Modem Physics [1]

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.756-758
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• 2006

Although LCD market has been divided so far into high-end market with S-IPS & SPVA and low-en market with TN mode, TN MNT has been striving towards bigger share in large and high-resolution wide display market as well. LG.Philips LCD has developed 20.1 inch and 22.0 inch WSXGA+ wide monitor mainly focusing on the low cost based on high brightness, fast R/T, high color gamut and wide viewing angle.

• 한국세라믹학회지
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• 제38권12호
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• pp.1085-1092
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• 2001

고효율 AC powder EL 소자를 초저가형과 저전력 소모형으로 분류하여 막의 두께와 제조된 유기결합제에 따라 스크린 프린팅법으로 제조하였다. 제조된 소자의 광전기적 특성을 평가하기 위하여 인가 주파수는 400Hz~1kHz, 인가 전압은 50~300 $V_{rms}$까지 변화시켜 휘도 및 전류밀도를 측정하였다. 주파수 및 전압공급원은 정현파 발생 장치로서 frequency generator를 이용하였다. 또한 휘도는 luminometer 의해 측정되었으며 전류밀도 측정을 위하여 multimeter를 사용하였다. 초저가형 AC powder EL 소자의 경우에는 가소제를 첨가하지 않고 발광층의 두께는 45~50$\mu\textrm{m}$이며 유전층의 두께는 약 10$\mu\textrm{m}$에서 43cd/$m^2$ 정도의 휘도와 20$\mu$A/$cm^2$정도의 전류밀도를 얻을 수 있었으며 저전력 소모형 AC powder EL 소자의 경우에는 15wt의 가소제 첨가하에 발광층의 두께는 45~50$\mu$m이며 유전층의 두께는 15~20$\mu$m에서 74cd/ $m^2$정도의 휘도와 30~40$\mu$A/ $m^2$정도의 전류밀도를 얻을 수 있었다. 또한 수명시간에 있어서 본 연구에서 제조한 AC powder EL 소자가 타사 제품보다 절대적으로 우수한 특성을 보였다.다.

• 펄프종이기술
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• 제42권1호
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• pp.1-6
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• 2010

Paper industry in Korea produces 14 million tons of paper and 1.3 million tons of sludge per year. Most of them has been treated by incineration, landfilling or ocean dumping. The sludge recycling to minimize the impact on the environment, so its importance is highlighted. In this study, in order to develop a new way of recycling the sludge, it was calcined and the recycled ash was tried to use as papermaking filler. Concerning the yield of calcium carbonate and the brightness and the rheology of the recycled calcination sludge, the optimum calcination conditions were found to be $600^{\circ}C$ and 12 hours. The sludge ash itself was not suitable for papermaking due to its color and low brightness. Thus the ash from the sludge was first mixed with a commercial filler and then utilized for papermaking. The effect of the increased hardness after high temperature treatment on wire abrasion was confirmed.

• 보존과학연구
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• 통권31호
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• pp.59-68
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• 2010

Cultural heritages are damaged by surrounding several environmental factors. Main factors are temperature, humidity, light, atmosphere and indoor pollutant, organism, etc. Therefore, to prevent damage of cultural heritage from such environmental factor, conservation environment monitoring becomes more important. Indicator is one of the simple method for environment monitoring. It can be used without expensive and complex equipments. However, it should be performed scientific examination for application to cultural heritage. In this study, some Temperature Indicators were chosen and reliability assessment was carried out for application to cultural heritage. Brightness($L^*$) is selected for reliability assessment factor. As a result of lab test, Temperature Indicators were not influenced greatly in humidity change. When they were exposed to setting temperature, the color was changed in setting temperature area and ${\pm}2^{\circ}C$ part of setting temperature. Especially brightness value was high in setting temperature area. Also, Temperature Indicators were stabilized after about 16 minutes when were exposed to temperature difference of $10^{\circ}C$ and when temperature difference with exposure environment is smaller, stabilization time shortened. Therefore, it is a possible to confirm that selected Temperature Indicator is reliable product through measurement of color difference value and naked eye observation.

• 마이크로전자및패키징학회지
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• 제14권2호
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• pp.1-8
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• 2007

LCD(Liquid Crystal Display) TV(Television) 용 백라이트의 광원으로서 면광원을 개발하였으며 이를 이용한 백라이트를 개발하였다. 백라이트의 광원으로 사용된 면광원은 유리성형을 통하여 채널을 형성하였으며 채널의 모양이 타원형 구조, 높이 4.4 mm, 채널의 실링 부위를 1.4 mm로 최적화된 면광원을 이용하여 제작한 백라이트의 성능을 향상시킬 수 있었다. 본 논문에서는 특히 면광원의 채널구조에 따른 백라이트의 휘도균일도의 변화에 대하여 연구하였으며 특히 광학 시뮬레이션을 통하여 면광원의 채널형상을 최적화 하였다. 채널의 구조가 최적화된 면광원을 이용하여 제작된 32", LCD TV의 휘도는 $576\;cd/m^2$ 이었다.

• 조명전기설비학회논문지
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• 제23권11호
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• pp.1-8
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• 2009

To compare the lighting environment of the living rooms in the apartments in Korea and China, this research conducted a study of the current status, targeting 79 households in Korea and 68 households in China. The results are the following. First, the two nations use mostly fluorescent light as the general lighting for the living room. China, in particular, share of not using the local lighting is very high. Secondly, levels of illumination was measured. The result demonstrates that the brightness of the lighting is higher in Korea compared to China while China demonstrates higher uniformity ratio for the levels of illumination compared to Korea. However, levels of illumination in general are very low in China. Thus, it cannot be concluded that China offers favorable lighting environment. Third, study on the degree of living room lighting's brightness and satisfaction level demonstrates that they are both average in Korea and China. As for the important points for the house lighting, most Koreans cited 'brightness of the lighting' while most Chinese said 'ease of maneuvering'.

• 대한가정학회지
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• 제48권5호
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• pp.17-24
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• 2010

Although design, color, and material are important elements in stage costumes, stage lightning also plays significant role in the presentation of stage costumes. Costumes color, material and perception can be significantly influenced by visual effects. Stage illumination can be arranged or managed so that colors are closely related to or enhanced or change the effects of costume colors on the runway or display at specific times. The results of this thesis are as follow; 1) Fabric tone, name, brightness, and chroma of colors were changed by the colors of stage lighting. 2) An achromatic color was changed to a chromatic color after being combined with colors of stage lighting. 3) Stage illuminations can make fabric, colors look similar to stage colors. 4) Plain satin silk fabric which reflects light shows high brightness and chroma after being influenced by stage lighting its shining effects and color changes were clear and apparent. 5) Velvet pile fabric which absorbs light shows low brightness and chroma after being influenced by stage lightning its shining effects and changes of colors were not clear and apparent. In conclusion, natural lights did not significantly influence fabric colors and perception, while artificial lights had wide range of effects on fabric colors and perception.

• 방송공학회논문지
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• 제21권5호
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• pp.816-823
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• 2016

본 논문은 디스플레이 휘도를 증가시키기 위하여 적색, 녹색, 청색 고휘도 Light Emitting Diode(LED)를 광원으로 사용하고, Digital Micro Device(DMD) 패널을 적용한 헤드업 디스플레이에서 세 개의 LED 광원 합성 비율과 합성에 따른 양자화 노이즈를 최소화시키는 LED 합성 비율을 연구하였고, 밝기에 영향을 미치는 녹색 LED 구동 비율과 접합 온도에 대하여 분석하였다. 이를 통하여 39%의 LED 중첩 방법을 통하여 황색과 청록색의 2차원 색을 합성하여 33.3%의 휘도 증대 효과를 얻을 수 있었다. 또한 양자화노이즈를 억제하고 영상 화질 측면에서 우수한 색정밀도를 얻을 수 있었다.