• 제목/요약/키워드: Light-off

검색결과 745건 처리시간 0.034초

LED광원을 이용한 실내상시보조인공조명(PSALI)의 성능평가에 관한 기초적 연구 (A Basic Study on Performance Evaluation of Permanent Supplementary Artificial Lighting of Interior(PSALI) using a LED Light Source)

  • 이진숙;김병수;김소연;정용규
    • 조명전기설비학회논문지
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    • 제25권4호
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    • pp.16-23
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    • 2011
  • Since the first lighting light source was invented, lighting has turned into superior-quality lighting considering the amenity of occupants, and the characteristics of a light source has developed rapidly. So this research confirmed the lighting performance of a dimmer control system and an ON-OFF control system via the existing light source, and analyzed the basic lighting environment of Permanent Supplementary Artificial Lighting of Interiors(PSALI) through the physical comparison and evaluation of a LED lamp substituted for a fluorescent lamp used in a dimmer control system, showing that the lighting physical quantity characteristics of an ON-OFF control system and a dimmer control system are similar to each other and that they are effective in terms of energy saving. Besides, it was shown that introducing a LED light source to a dimmer control system improves lighting environments and largely reduces energy consumption.

Analysis of Polarization Properties of Optical Isolator for Fiber Laser

  • Kim, Tae-Gon;Cheon, Min-Woo;Park, Yong-Pil;Cho, Kyung-Jae;Kang, Sung-Hak
    • Transactions on Electrical and Electronic Materials
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    • 제12권6호
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    • pp.241-244
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    • 2011
  • An isolator transmits light in the forward direction and blocks light from passing in the reverse direction. It is regarded an essential optical component in medical, industrial, and research lasers for blocking reflection beams that cause optical damage and noise. It is also used as a communicative light intensifier to expand the lifespan of devices and enhance transmission quality. This study analyzed the characteristics of the core components in the construction of a polarization-independent isolator, namely, the walk-off polarizer and the Faraday rotator. Measurement of the extinction ratio of the resultant walk-off polarizer revealed that the ratio between the vertical and horizontal rays was 1,050:1 with a laser output of 0.032 W and 1,010:1 with a laser output of 2.68 W, thus presenting ratios similar to 1,000:1. In addition, the walk-off polarizer and Faraday rotator constructed in this study were used to compare output changes according to changes in power of input light and to check the penetration ratio. Results from the study presented variations in output value according to changes in power of input light. However, the average penetration ratio remained relatively consistent (~81.4%).

배경이 물체에 겹치지 않는 영상에서 잡음에 대한 안정성, 출력의 최대값 크기, 광효율을 고려한 최적 Trade-off 필터 (Optimal trade-off filters for Noise Robustness, Peak Sharpness and Light Efficiency in the Nonoverlapping Background Noise)

  • 성영경;최태선
    • 대한전자공학회논문지SP
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    • 제37권4호
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    • pp.56-64
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    • 2000
  • 본 논문에서는 패턴인식의 문제에서 배경이 물체에 겹치지 않는 영상일 때 잡음에 대한 안정성, 피크의 크기와 광효율의 조건에 대한 trade-off를 통해 필터를 설계하는 방법에 대해 언급한다. 필터를 설계하기위해 신호대 잡음비, 출력의 최대값대 출력에너지비, 광효율의 세가지 다른 조건을 사용한다. 필터의 성능을 시험하기 위해 여러 형태의 잡음과 필터 계수에 대해 컴퓨터 모의실험을 실시한다. 배경이 물체에 겹치지 않는 영상에 대해 기존의 필터보다 우수한 성능을 얻을 수 있다.

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Environmental Pollution of Ondal Cave

  • Sin, Dae-Bong
    • 동굴
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    • 제85호
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    • pp.15-17
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    • 2008
  • This paper is attempted to review a cave restoration and preservation plan against environmental destruction and pollution as a preliminary survey for preservation of cave environment. Consequently, it's important to throw an indirect light rather than direct light on cave formations, keeping distance of 2m at least. The already existing moss should be removed using wet cloth or sponge as soon as possible. If it's washed off, be careful not to splash it or water on nearby subjects. Based on an automatic switch-off system, light will automatically turn off when no one is left in the cave. It's also recommended to dualize the cave passage and partially close the cave by taking turns to give a time to recover.

시동 배기가스 점화기술을 이용한 촉매의 예열시간 단축 (Fast Light-Off of Catalyst using Cranking Exhaust Gas Ignition)

  • 조용석;엄인용;이윤석;김득상;김충식;천준영;최진욱
    • 한국자동차공학회논문집
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    • 제9권2호
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    • pp.43-49
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    • 2001
  • In order to satisfy the ULEV emissions regulation, fast light-off of a catalyst is essential for reduction of HC and CO emissions during the cold start. Cranking Exhaust Gas Ignition(CEGI) method developed in this study showed that the catalyst reaches the light-off temperature in a few seconds. The CEGI stops the ignition signal for a few seconds during the cranking period, so the unburned fuel-air mixture bypasses the combustion chamber and flows through the exhaust manifold. When the unburned mixture reaches two glow plugs installed upstream of the catalyst, it burns and releases the thermal energy to heat up the catalyst, In the FTP-75 vehicle tests, the CEGI showed that the exhaust emissions reduced by 47.7% for THC and by 88.6% for CO in the cold-transient phase of the test.

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사무실 및 학교 교실의 조명용 소비전력량 절감방안 연구 (A Study on the Plan for Reducing Electricity Consumed to Light up in Offices and Classrooms)

  • 이광수;장우진
    • 한국조명전기설비학회:학술대회논문집
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    • 한국조명전기설비학회 2007년도 추계학술대회 논문집
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    • pp.179-182
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    • 2007
  • 현재 우리나라 대부분의 사무실 및 학교교실에는 형광등 스위치가 창측, 중간, 복도측등으로 회로가 분리되어 있으나 날씨가 맑고 태양빛이 많이 비치는 경우(기준조도 이상)에도 창측의 형광등이 항상 켜져 있는 경우가 대부분이므로 외부 쪽 창측에 설치되는 형광등기구에 외부광량(일조량)에 따라 자동으로 ON, OFF되는 센서가 부착된 형광등기구를 사용하여 에너지가 절감될 수 있는 방안을 연구하고 자한다.

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경항공모함 이·착함 성능평가 및 안전임무 수행범주 일관 해석 연구 (A Study on Short-Take-Off and Vertical Landing (STOVL) Performance Evaluation of a Light Aircraft Carrier and a Consistent Analysis of Safe Operating Envelope (SOE))

  • 홍사영;박동민;정재환;서민국;조석규
    • 대한조선학회논문집
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    • 제61권2호
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    • pp.125-134
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    • 2024
  • The Safe Operating Envelope (SOE) combined with Short-Take-Off and Vertical Landing (STOVL) performance is an essential consideration of a light aircraft carrier for design of hull shape with excellent seakeeping performance in terms of naval air operations as well as traditional naval ship missions such as Transit and Patrol (TAP), and Replenishment at Sea (RAS) and so on. A variety of procedures are systematically combined to determine SOE considering rather complicated missions associated with operation of aircraft onboard. The evaluation of take-off and landing safety missions onboard should consider wind effect on deck and severer seakeeping indices and standards compared with conventional naval ships. In order to support take-off and landing missions, various support activities of the crews are required. So, additional evaluation is needed for indicators such as MSI(Motion sickness Index) and MII(Motion Induced Interruptions), which are quantitative indicators of work ability that appear as a result of motion response. In this study, a standard procedure is developed including the seaworthiness performance indicators, standards, and evaluation procedures that should be considered during design of STOVL aircraft carrier. Analysis results are discussed in terns of air-wake on deck as well as seakeeping indices associated with design parameter changes in view of conceptual design of a light aircraft carrier.

High Efficiency Hybrid White Organic Light-Emitting Diodes for Reduced Efficiency Roll-Off and Color Stability

  • Seo, Ji-Hoon;Park, Jung-Sun;Kim, Jun-Ho;Koo, Ja-Ryong;Seo, Bo-Min;Lee, Kum-Hee;Park, Jeong-Keun;Je, Jong-Tae;Yoon, Seung-Soo;Kim, Young-Kwan
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.418-420
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    • 2009
  • The Authors have demonstrated high efficiency hybrid white organic light-emitting diodes (HWOLED) for reduced efficiency roll-off and color stability. It was shown that HWOLED fabricated in this study have the maximum luminance of 46 420 cd/$m^2$ at 8 V (turn-on voltage of 2.7 V), external quantum efficiency of 13.18%, power efficiency of 28.75 lm/W at 1 000 cd/$m^2$, and reduced efficiency roll-off of 2.7 times than control white device. The HWOLED also showed the stable color shift with $\Delta$Commission Internationale de I'Eclairage coordinates coordinates of ${\pm}$ (0.00, 0.00) from 100 to 10000 cd/$m^2$.

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Characteristics of Motion-blur Free TFT-LCD using Short Persistent CCFL in Blinking Backlight Driving

  • Han, Jeong-Min;Ok, Chul-Ho;Hwang, Jeoung-Yeon;Seo, Dae-Shik
    • Transactions on Electrical and Electronic Materials
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    • 제8권4호
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    • pp.166-169
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    • 2007
  • In applying LCD to TV application, one of the most significant factors to be improved is image sticking on the moving picture. LCD is different from CRT in the sense that it's continuous passive device, which holds images in entire frame period, while impulse type device generate image in very short time. To reduce image sticking problem related to hold type display mode, we made an experiment to drive TN-LCD like CRT. We made articulate images by turn on-off backlight, and we realized the ratio of Back Light on-off time by counting between on time and off time for video signal input during 1 frame (16.7 ms). Conventional CCFL (cold cathode fluorescent lamp) cannot follow fast on-off speed, so we evaluated new fluorescent substances of light source to improve residual light characteristic of CCFL. We realized articulate image generation similar to CRT by CCFL blinking drive and TN-LCD overdriving. As a result, reduced image sticking phenomenon was validated by naked eye and response time measurement.

Ti 전극의 Lift-off 공정을 이용한 홀 패턴 형성과 TCO-less 염료감응형 태양전지의 응용 (A Formation of Hole Pattern on Ti Electrode by Lift-off and Its Application to TCO-less Dye-sensitized Solar Cells)

  • 정행윤;기현철;구할본
    • 한국전기전자재료학회논문지
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    • 제28권3호
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    • pp.175-179
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    • 2015
  • In this study, we propose Ti hole pattern structure on the transparent conductive oxide (TCO) less dye-sensitized solar cells (DSSCs) using the lift-off process to improve the low light transmittance and low efficiency caused by opaque Ti electrode. The formation of Ti hole patterns make it possible to move the dye adsorption and electrolyte. The DSSCs with Ti hole patterns showed a higher photoelectric conversion efficiency (PCE) than those with general structure by 11.1%. As a result, The Ti hole pattern structure can be improved to increase the light absorption of the dyes and PCE of the TCO-less DSSCs is also increased.