http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
편광상이 고리 구조 기반 사냑 간섭계를 이용한 편광 간섭형 광섬유 압력 센서
류우찬(Uh-Chan Ryu),최성욱(Sung Wook Choi),이용욱(Yong Wook Lee) 한국조명·전기설비학회 2015 조명·전기설비학회논문지 Vol.29 No.7
In this paper, we demonstrated a polarimetric fiber pressure sensor using a polarization-diversity-loop-based Sagnac interferometer(PDLSI) composed of polarization-maintaining fiber(PMF) and a fiber Bragg grating(FBG). In order to compare the pressure sensitivity for various kinds of PMF, three kinds of bow-tie PMF were employed as sensor heads. The maximum pressure sensitivity was measured as approximately -15.07㎚/MPa, and an R2 value to represent sensor linearity was measured as ∼0.992 at the sensor system using corresponding PMF over a pressure range of 0-0.3MPa. An FBG was utilized and located adjacent to the PMF segment for compensating temperature-induced errors in the measurement of pressure. The pressure sensitivity of the proposed sensor was improved by approximately four times compared with the previously reported pressure sensor based on polarization-maintaining photonic crystal fiber.
Multi-chip LED의 RBG 색상 변화에 따른 LED조명의 CRI, CCT 변화 연구
조형섭(Hyeong-Seob Jo),류우찬(Uh-Chan Ryu) 한국조명·전기설비학회 2016 조명·전기설비학회논문지 Vol.30 No.12
Recent studies have been made to develope various methods for improving color rendering property of multi-chip LEDs, due to their variety of colors and color temperatures. It is well known that RGB multi-chip LEDs have different color rendering indices according to the correlated color temperatures and barely have a CRI above 90. In the paper, we reviewed the CRI variations with the changing the peak wavelengths of commercially available RGB LEDs in the previous papers and standards. And varying the spectral bandwidths of the RGB LEDs, CRI higher than 90 can be accomplished in the CCT ranging from 2000K to 6000K. The possibility of a CRI higher than 95 was proposed by controlling the spectral characteristics.
시뮬레이션 프로그램을 이용한 Melanopic-to-photopic Ratio(α-opic) 및 연색특성 향상에 대한 연구
김종오(Jong-Oh Kim),류우찬(Uh-Chan Ryu) 한국조명·전기설비학회 2022 조명·전기설비학회논문지 Vol.36 No.4
Invention of artificial lights has extended human activity time, which has greatly contributed to the development of modern civilization. However, continuous exposure of artificial lights has reduced human sleeping time, which causes a decrease in melatonin production resulting in the side effects such as insomnia, depression, and so on. To prevent the reduction of melatonin by the artificial lights, LED packages helping melatonin generation have been developed. While the commercial LED packages have a high melanopic to photopic ratio (M/P ratio) due to their peak wavelength near the melatonic response around 490nm, those cannot accurately express several colors, that is, give a low R<SUB>9</SUB> or R<SUB>12</SUB> value less than 60 resulting from the peak. Since M/P ratio has a similar formula to that of scotopic to photopic ratio (S/P ratio), the former would have a trade-off relation with color rendering properties as the latter. Therefore, those should be optimized to have values above a certain level by adjusting LED package’s spectral compositions. In this study, M/P ratio and color rendering characteristics were simulated by special combination of 4 blue LEDs and 7 types of phosphors. As a result, the M/P ratios were 0.67, 0.72, 0.78, 0.9, 1.04, 1.14, 1.23, and 1.35 or more. Also, the color rendering properties were R<SUB>a</SUB>≥89, R<SUB>9</SUB>≥75, R<SUB>12</SUB>≥80, R<SUB>9-14</SUB>≥83, and Q<SUB>a</SUB>≥79.
Melanopic to photopic ratio(alpha-opic)와 연색성 향상을 위한 스펙트럼조합 시뮬레이션 연구
김종오(Jong-Oh Kim),류우찬(Uh-Chan Ryu) 한국조명·전기설비학회 2021 한국조명·전기설비학회 학술대회논문집 Vol.2021 No.11
In this study, changes in melanopic to photopic ratio and color rendering index were simulated by combining the blue LEDs spectrum and 7 types of phosphors.
LED조명기기에 대한 플리커 안전기준 적용 방안에 관한 연구
노경호(Kyung-Ho Noh),류우찬(Uh-Chan Ryu) 한국조명·전기설비학회 2017 조명·전기설비학회논문지 Vol.31 No.9
As LED(Light Emitting Diode) lighting market is emerging as a growth engine in lighting business, the demand of certifications from domestic and foreign companies is increasing exponentially. At this point, flicker problem of LED lighting which adversely affects the human body has been raised as an issue. Furthermore, the domestic safety standards for the flicker have not been established and safety vulnerabilities are exposed in real life under LED lightings such as home, office and for children. Thus, it is urgent to establish institutional standards. In this paper, flicker safety standards of LED lightings for human body are suggested to secure consumer safety by measuring flicker levels of commercially available LED lightings.
조명용 고출력 발광다이오드의 Decapsulation 기술
임수현(Sue-Hyun Lim),류우찬(Uh-Chan Ryu),조용익(Young-Ick Cho),여인선(In-Seon Yeo) 한국조명·전기설비학회 2011 한국조명·전기설비학회 학술대회논문집 Vol.2011 No.5월
고출력 발광다이오드(LED)는 장수명, 저전력, 친환경 등의 장점이 있어서 기존 조명 대체용 조명 광원으로 각광받고 있으나 LED조명 온도 상승은 열화 및 Wire 단선을 야기하여 고장을 일으킨다. 고장 제거 및 고장 재발 방지를 위해 발생 고장의 고장모드에 대한 체계적인 분석 과정이 필요하다. 본 연구에서는 조명용 고출력 LED 케이스 제거 방법인 Decapsulation에 대해 알아보고자 한다.