• 한국인쇄학회지
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• 제29권2호
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• pp.33-44
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• 2011

The inorganic powder EL lamp was made by screen printing technique with a phosphor ink and a dielectric ink. The thickness of a phosphor ink layer and a dielectric ink layer is $35{\mu}m$ and $54{\mu}m$ respectively. A increasing ratio of the luminance of inorganic powder EL lamp to be a 1P1PD-phosphor ink layer in which increased voltage at constant frequency is higher 12% than when increased frequency at constant voltage. It is higher 57% than when increased frequency at constant voltage that the rate of increase of the luminance of inorganic powder EL lamp to be a 2PD-phosphor ink layer in which increased voltage at constant frequency. Finally, when increased voltage at constant frequency, a increasing ratio of the luminance of inorganic powder EL lamp to be a 2PD-phosphor ink layer is higher about 40% than that to be a 1P1PD-phosphor ink layer.

• 한국안광학회지
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• 제4권1호
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• pp.63-68
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• 1999

공간주파수에 따른 contrast sensitivity를 측정할 수 있는 새로운 방법으로 차트를 제작하기 위해 차트 화면 최대 luminance값을 100%로 하여, 격자주파수의 mean luminance를 25, 50, 75%의 3개형태로 만들어 CS값 0 에서 $10^3$ 값이 되도록 하였다. 초등학생 5학년을 대상으로 공간주파수에 따른 CS값의 측정결과 평균 luminance 값이 떨어질수록 CS값은 감소되고, peak 위치도 low spatial frequency 쪽으로 이동하였다. 약시인 사람은 고주파수쪽에서 CS가 감소하거나, 전체주파수 공간에서 CS값이 감소하였다. 격자순응에 의해 CS 측정값은 순응된 공간주파수의 주변 영역에서 CS가 감소된다.

• 한국도로학회논문집
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• 제20권1호
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• pp.117-126
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• 2018

PURPOSES : The purpose of this paper is to analyze the change in lane reflection performance through lane washing and sweeping on highway lanes. METHODS : This paper compared and analyzed the changes in lane reflection performance before and after lane washing and sweeping. The research method was as follows. First, we selected four research sites on the Gyeong-bu Highway. Second, the parameters affecting lane reflection performance are classified into luminance, brightness, and number of glass beads. Third, the change in reflection performance was measured after washing /sweeping at the same place after studying 60m of the unwashed/unswept area. Fourth, the measurement results were compared and analyzed before and after lane washing/sweeping. RESULTS : The results of this study are as follows. First, lane washing improved the luminance and brightness by 4.2~21.4% and 1.4~5.1%, respectively, and reduced the number of glass beads per wash by 0.2~1.2%. Second, lane sweeping improved the luminance and brightness by 2.3~8.5% and 0.8~2.3%, respectively, and reduced the number of glass beads per sweep by 0.8~4.9%. CONCLUSIONS : By comparing the results of lane washing and sweeping, it was found that compared to lane sweeping, lane washing improved the luminance and fewer glass beads were dropped.

• Transactions on Electrical and Electronic Materials
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• 제8권6호
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• pp.268-273
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• 2007

In this study, It was studied about the luminance characteristics of 17 inch direct-type back light using EEFL(external electrode fluorescent lamp) and CCFL(cold cathode fluorescent lamp). The EEFL has a long life time because the electrode is installed outside of lamp. And it is produced in lower price than conventional CCFL. Moreover, it does not need process of installing internal electrode. However, the EEFL technology has several problems such as difficulty of designing driving inverter and preventing this phenomenon along the skin of lamps. We suggested two types of backlight unit for LCD TV application using the EEFL and the CCFL. We found optimized optical design parameters. We set the optical variation parameters such as lamp height, lamp distance, total thickness, and angles of inner walls. We achieved 7580 nits of center luminance, 82% of luminance uniformity by using 20 lamps of the EEFL and 7297 nits of center luminance, 78% of luminance uniformity by using 16 lamps of the CCFL.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2001년도 추계종합학술대회
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• pp.613-616
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• 2001

공 부활제로 KCI, Cl, S 및 P를 각각 첨가한 발광충을 전자 빔 방법에 의해 성장시킨 2중 절연구조의 SrS:Ce electroluminescent(EL) device를 제작하여, 공 부활제가 EL device의 휘도에 미치는 영향을 조사였다. 휘도 및 발광파장은 첨가되는 공 부활제 및 농도에 의하여 상당한 영향을 받고 있음을 알았다. 어느 공 부활제에서나 전체 휘도는 0.2 mol%에서 최고를 나타냈으며, CeCl$_3$+KCL를 첨가한 소자가 최고 850cd/$m^2$를 나타내었다. 또한 CeP를 첨가한 소자의 경우 전체 휘도는 낮았으나 청색 휘도의 비율은 가장 높았으며, 이 비율은 농도의 상승에 따라 증가했다.

• KIEAE Journal
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• 제10권6호
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• pp.97-103
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• 2010

Sky simulator is a effective daylighting design tool that can evaluate three dimensional performance of lighting. Especially, the dome type sky simulator offer reliable and reproducible daylighting performance with different standard sky models. Recently, K university has developed the dome type sky simulator(sky dome) with the diameter of 6.5m and the height of 3.7m. The sky dome consists of a group of 145 large steel panels with 72 halogen lamps which are arranged in a circular array. The luminance distribution of the sky dome can be calibrated by changing the angle and the brightness of the lamps respectively. To allow more reliable prediction and evaluation of daylighting through the sky dome, It is essential to validate the sky luminance distribution of the sky dome. This study consider the validation of the comparisons between the measured and the calculated luminance values for the CIE standard overcast sky. Also, the error rate between the measured and the calculated luminance values were compared to the previous studies. The results indicated that the K university sky dome can reproduce reliable CIE standard overcast sky with the average relative error rate of 4.4% and root-mean-square error(RMSE) of 5.4%.

• E2M - 전기 전자와 첨단 소재
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• 제10권2호
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• pp.150-155
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• 1997

Powder type electroluminescent device(P-ELD) in this study was prepared by printing method. P-ELDs were basically composed of phosphor, insulator and transparent conducting layer. The phosphor powder was prepared by sintering the mixture of ZnS as a host, Cu as an activator, and NaCl as a flux for co-activator and enhancement of growth of the phosphor particles. The phosphor layer was made by printing the paste of the cyanoethylpullan as a binder and the ZnS system phosphor powder. In order to evaluate the luminescence characteristics of ZnS P-ELD, applied voltage - luminance(V-L), frequency-luminance(f-L), and relative luminance spectra(L- .lambda.) characteristics were measured. The experimental results show that luminance increased with increasing the applied voltage and frequency. It can be explained in terms of the potential barrier formed between ZnS and CuS. Two emission peaks in luminance-wavelength spectra measured at applied voltage of 100 $V_{rms}$ were observed at 500nm as a primary peak and 460nm as a secondary peak, respectively.y.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 광주전남지부
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• pp.35-38
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• 2006

As a display becomes large recently, Acquisition of high luminance and Luminance uniformity is becoming difficult in the existing CCFL or EEFL backlight system. So, study for a performance enhancement has enforced. but lamp development of flat type is asked for high luminance and a luminance uniformity security in of LCD and area anger trend ultimately. In this paper, we changed a tip shape of an electrode for production by the most suitable LCD backlight surface light source, and confirmed discharge characteristic along discharge gas pressure and voltage, and confirmed electric field distribution and discharge energy characteristic through a Maxwell 2D simulation. Therefore the discharge firing voltage characteristic showed a low characteristic than a rectangular type and round type in case of electrode which used tip of a triangle type, and displayed a discharge electric current as a same voltage was low.

• 조명전기설비학회논문지
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• 제23권12호
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• pp.31-40
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• 2009

미국의 라스베가스, 중국의 상해와 홍콩은 많은 관광객들이 찾는 명소로 다양한 기법과 방식을 사용한 경관조명이 복합적으로 어우러져 있는 세계적으로 야경이 유명한 도시이다. 이러한 3개 도시를 대상으로 건물 야간경관조명의 조명 방식과 조명 기법을 조사하였으며, 건물의 최대 최소 벽면휘도, 부분적인 발광광고물에 대한 휘도를 측정하였다. 그리고, 현재 사용되고 있는 CIE 휘도 기준과 IES 권장 최대 휘도비에 대한 기준을 바탕으로 각 도시별, 건물별 벽면휘도의 절대값, 상대값의 비교를 통해 도시별 경관조명 특성을 분석하였다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2006년도 춘계종합학술대회
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• pp.565-568
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• 2006

휘도-색차 신호에서 휘도 신호는 그레이 영상을 생성하고, 각각의 컬러 요소들을 단색 시스템으로 호환할 수 있다. 그리고 휘도-색차 신호의 각 컬러 요소들은 적은 상관 관계를 가지므로 신호를 부호화 또는 변조하는데 유용성을 지닌다. 그러나 각 컬러 신호들은 통계적으로 적은 상관 관계를 가지나 서로 독립적이지는 않다. 그러므로 본 논문은 컬러 요소들 간의 상호 의존적인 특징을 고려하여 웨이브릿 기반의 주파수 영역에서 휘도-색차 신호에 대한 워터마크 삽입 알고리즘을 제안한다. 따라서 디지털 워터마크의 견고성과 비시각성을 보장할 수 있다.