• 한국산학기술학회논문지
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• 제8권3호
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• pp.477-482
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• 2007

본 논문은 램프의 벌브 형태 개선과 알루미늄 코팅에 의한 리플렉터 글로브의 적용으로 광을 집적하여 증가시키고, 레늄 필라멘트의 적용에 따른 장 수명과 크립톤 가스와 질소가스의 최적 주입 비율을 통한 60[W]급 Basking Neodymium Lamp 개발에 관한 것으로 이를 측광, 분석하였다. 개발결과 수명은 7,200시간, 광속은 620[1m]이며 색온도와 연색성 또한 우수한 것으로 나타나 농업용과 일반용 램프로써의 그 가능성을 확인하였다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제54권12호
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• pp.585-587
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• 2005

In this paper, We studied two methods to measure optical characteristics of an electrodeless light source using the integrating sphere(diameter 1.5m). One is to use a center measurement method and the other is to use a side measurement method. As a result of analysis, a side measurement methode without auxiliary lamp is almost similar against a center measurement with auxiliary lamp to reduce a measurement of an error for luminous flux, luminous efficacy and spectral distribution etc. Therefore, Sample which cannot measured by reason of big size and heavy weight can be measured by a side measurement method.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.465-466
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• 2007

In electrode-less lamp, The key point in creating an efficient light source based on RF discharge is to minimize the RF power loss in the RF coupler which for Anderson's type of RF lamp is due to losses in the ferrite core. This loss depends on the particular ferrite material, its size, geometry, frequency in this kind of inductive lamp shows that the correct choice of discharge current has a crucial effect on the core loss. In this study, we measured Ferrite temperature in normal state, then analyzed electrical and optical characteristics according to ferrite shape. We were able to know that was ferrite of the antenna had relate closely with temperature and luminous of the lamp. Also we appraised temperature and electrical, optical properties during turn on the lamp.

• 한국결정성장학회지
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• 제25권1호
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• pp.35-38
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• 2015

LED는 소비전력 절감, 사용수명 증가, 발광 파장 변화를 통한 다변적 적용이 가능하여 에너지 효율 증대의 대안으로 각광받고 있으며, 조명뿐만 아니라 디스플레이 백라이트, 차량용 헤드라이트 등 다양한 분야에 적용되고 있다. 현재 백색 LED를 구현하는 데에는 청색 LED와 황색 형광체를 혼합하는 방식이 주로 활용되며, 황색 형광체로는 YAG : $Ce^{3+}$가 많이 이용된다. 기존에는 형광체를 epoxy resin과 혼합하여 LED chip 위에 도포하여 경화시키는 패키징 방식을 주로 사용하였다. 하지만 페이스트 기반 패키징 방식은 열에 의한 형광체의 특성 저하와 효율 감소 문제를 일으킨다. 이러한 문제를 해결하기 위해 형광체 플레이트를 이용한 remote 방식이 이용되고 있지만, 플레이트 내부 전반사로 인한 광 효율 손실 또한 해결해야 할 문제이다. 본 연구에서는 플레이트 측면을 Ag로 코팅함으로써 플레이트 내부의 전반사에 의한 광 효율 손실을 해결하고자 하였다.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2002년도 학술대회논문집
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• pp.3-8
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• 2002

In this paper, We measured an electric and optical characteristics for electrodeless fluorescent lamp system. We used the CCD(charged couple device) and Integrating Sphere Photometer to detect the accurate variation of data and got a characteristic of output voltage and current, luminance, luminous flux etc. And then we come to understand that the efficiency of electrodeless fluorescent lamps are similar to CFLs(compact fluorescent lamp) or HID(high intensity discharge lamp).

• 대한인간공학회지
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• 제7권1호
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• pp.39-44
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• 1988

Because the moving visual acuity is less than the static visual acuity, a new headlight system was designed and manufactured to make reparation for that. Then the new headlight system was built in a passenger car and some experiment was achieved. When the car is accelerated the luminous flux of headlight is augmented. When the speed of the car was increasing, the new system was effective, but when the car was decelerated the system was less effective.

• Journal of Advanced Marine Engineering and Technology
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• 제35권5호
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• pp.654-660
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• 2011

본 논문에서는 함정용 노출 방수형 형광등기구 대체를 위한 LED 조명기구의 설계방안에 대하여 연구하였다. 조명기구에 대한 한국산업규격(KS), 국방규격(KDS) 및 미국방규격(MIL)의 안전 및 성능 요구사항을 비교하였다. LED 등기구의 설계기준을 도출하기 위하여 기존 형광등기구의 소비전력, 총광량 및 배광 등 전기 광학적 특성을 실험적으로 분석하였다. 기존 조명기구의 성능을 기초하여 4가지 LED 조명기구를 시제작하였다. 기존 형광등에 비해 소비전력은 44~51 [%] 절감되고, 총광속은 8~13 [%] 증가하는 함정용 LED 조명기구의 설계방안을 제시하였다.

• Current Optics and Photonics
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• 제1권4호
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• pp.389-395
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• 2017

This paper investigates a method to improve the lighting performance of white light-emitting diodes (WLEDs), which are packaged using two separate remote phosphor layers, a yellow-emitting YAG:Ce phosphor layer and a red-emitting ${\alpha}-SrO{\cdot}3B_2O_3:Sm^{2+}$ phosphor layer. The thicknesses of these two layers are $800{\mu}m$ and $200{\mu}m$, respectively. Both of them are examined in conditions where the average correlated color temperatures (CCT) are 7700 K and 8500 K. For this two-layer model, the concentration of red phosphor is varied from 2% to 30% in the upper layer, while in the lower layer the yellow phosphor concentration is kept at 15%. It was found interestingly that the lighting properties such as color rendering index (CRI) and luminous flux are enhanced significantly, while the color uniformity is maintained in a relatively close range to the one of one-layer configuration (measured at the same correlated color temperature). Besides, the transmitted and reflected light of each phosphor layer are revised by combining Kubelka-Munk and Mie-Lorenz theories. Through analysis, it is demonstrated that the packaging configuration of two-layer remote phosphor that employs red-emitting ${\alpha}-SrO{\cdot}3B_2O_3:Sm^{2+}$ phosphor particles provides a practical solution for general WLEDs lighting.

• 천문학회지
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• 제35권1호
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• pp.1-7
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• 2002

We have studied the long-term X-ray light curve (2-10 keV) of the luminous Seyfert 1 galaxy MCG-2-58-22 by compiling data, from various X-ray satellites, which together cover more than 20 years. We have found two distinct types of time variations in the light curve. One is a gradual and secular decrease of the X-ray flux, and the other is the episodic increase of X-ray flux (or flare) by a factor of 2-4 compared with the level expected from the secular variation. We detected 3 such flares in total; a representative duration for the flares is $\~$2 years, with intervening quiescent intervals lasting $\~$6-8 years. We discuss a few possible origins for these variabilities. Though a standard disk instability theory may explain the displayed time variability in the X-ray light curve, the subsequent accretions of stellar debris, from a tidal disruption event caused by a supermassive black hole in MCG-2-58-22, cannot be ruled out as an alternative explanation.

• 대한기계학회논문집B
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• 제26권11호
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• pp.1503-1512
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• 2002

From the view of the environmental protection against the use of fossil fuels, a great of efforts have been exerted to find an alternative energy source. Hydrogen may become an alternative However the product species of the hydrogen flame is only $H_2O$, which emits only non-luminous radiation so the radiation from it is much smaller than that for a hydrocarbon flame. In this study, the authors designed and fabricated a laboratory scale test furnace to study thermal characteristics of hydrogen-air diffusion flame. In addition. the effects of addition of reacting as welt as non-reacting solid particles were experimentally investigated. Among the total heat flux to the wall, about 75 % was occupied by radiation while 25% by convection. When the aluminum oxide (Al$_2$O$_3$) particles were added, the radiative heat flux was reduced due to heat blockage effects. On the other hand, the total as well as the radiative heat flux was increased when the carbon particles were seeded, since the overall temperature increased. The effects of swirl and excess air ratio were also examined.