• 제목/요약/키워드: Light Condition

검색결과 2,476건 처리시간 0.024초

차광재 종류가 묘삼의 광합성, 형태 및 생육에 미치는 영향 (Photosynthetic, Morphological and Growing Characteristics by Shading Materials in Panax ginseng C. A. Meyer)

  • 조진웅;박홍우;김민정;김현호;최재을
    • 한국작물학회지
    • /
    • 제53권3호
    • /
    • pp.256-260
    • /
    • 2008
  • 본 연구는 이식 재배를 위한 건전 우량 인삼묘 생산을 위하여 해가림 내의 광량이 1년생 인삼의 광합성 및 형태적 특성에 대하여 조사하였다. 투과율에 따른 인삼의 엽록소 함량 및 광합성은 광 투과율이 높을수록 감소하는 경향을 보였으며, 광 투과율이 높은 조건은 잎이 생리적 장해를 받아 황변하는 모습을 보이고 있고, 줄기는 하피가 형성되었으며, 줄기의 유관속내 사부의 발달이 현저하게 위축되었다. 또한 뿌리는 광량이 높을수록 표피가 파괴되는 모습을 보였으며 형성층의 발달이 적었다. 뿌리 수량 역시 광 투과율이 높을수록 감소되었다.

색렌즈의 광투과율에 따른 대비감도 변화 (Changes of Contrast Sensitivity According to Light Transmittance of Color Lenses)

  • 이선행;이윤정;조현국
    • 한국산학기술학회논문지
    • /
    • 제10권11호
    • /
    • pp.3427-3433
    • /
    • 2009
  • 본 연구는 착색렌즈의 광투과율에 따른 명소시 대비감도의 변화를 분석하여 색렌즈를 착용할 때 색상에 따른 적절한 광투과율 기준을 제시하고자 하였다. 정상 시기능을 가진 남자 24명과 여자 13명을 대상으로, 광투과율 80~90%, 60~80%, 43~60%, 30~43%로 착색된 4개의 색렌즈(회색, 갈색, 적색, 녹색)를 순서대로 착용시키고 F.A.C.T. 시표를 이용하여 대비감도 검사를 실시하였다. 검사 결과, 광투과율이 감소될수록 대비감도는 감소되었고, 시감도는 갈색이 가장 높고 적색이 가장 낮은 것으로 나타났다. 대비감도 검사결과를 고려한 색상별 권장 광투과율은 갈색, 회색과 녹색 38% 이상, 적색 52% 이상인 것으로 나타났다. 이러한 결과들로 보아 일상생활에서 눈을 보호할 목적으로 색렌즈를 선택할 때 색상과 그 색상에 적절한 광투과율이 고려되어야 한다.

철도차량 LED 실내등 적용 검토 (Consideration of LED Saloon light for rolling stock)

  • 정현정;김신국;안홍관;김재기
    • 한국철도학회:학술대회논문집
    • /
    • 한국철도학회 2011년도 춘계학술대회 논문집
    • /
    • pp.1457-1465
    • /
    • 2011
  • The saloon light is the device that can offer convenience and comfort to the driver and passenger when the train is operated at night or in the tunnel. Generally, The fluorescent type saloon for the rolling stock have been used, but the problems that are short life and the generation of heat have been brought about because the saloon lihgts of rolling stock are supposed to operated continuously long time, and high power consumption. So, the development of new type of saloon lights has been requested in order to solve these problems. And recently the various LED type lights have been developed and LED type saloon lights for rolling stock also has been developed. Therefore, we survey the characteristic, function and needed condition of the LED type saloon lights for rolling stock, and analyze the good and bad point, and then research the complement of weak point. We want to find the direction and develop the design of future LED saloon light type.

  • PDF

창공-91 실속속도 비행시험 (Flight Test of Stalling Speed for ChangGong-91)

  • 이정훈;김칠영
    • 한국항공운항학회지
    • /
    • 제16권3호
    • /
    • pp.1-6
    • /
    • 2008
  • The stalling speed flight test of light airplane, ChangGong-91, was performed to acquire the certification. With power-off engine condition, the wings level stall flight tests were conducted at the aircraft configuration of various flap angle - clean, 20degree, and full flap, respectively. They were performed considering with the combination of the maximum and minimum test weight, and forward and afterward center of gravity. The stalling speeds and the minimum speeds of light airplane were determined from the results of flight test. Also, the appropriateness of stall warning speeds are evaluated through the flight test measures. The airplane is recoverable only with pitch control and engine throttle from stall state without exceptional operation.

  • PDF

A Study on ZnSSe : Te/ZnMgSSe DH Structure Blue and Green Light Emitting Diodes

  • Lee Hong-Chan
    • Journal of Advanced Marine Engineering and Technology
    • /
    • 제29권7호
    • /
    • pp.795-800
    • /
    • 2005
  • The optical properties of $ZnS_{y}Se_{1-x-y}:Te_x\;(x\;<\;0.08,\;y\∼0.11$) alloys grown by molecular beam epitaxy (MBE) have been investigated by photoluminescence (PL) and PL-excitation (PLE) spectroscopy. Good optical properties and high crystal quality were established with lattice match condition to GaAs substrate. At room temperature, emission in the visible spectrum region from blue to green was obtained by varying the Te content of the ZnSSe:Te alloy. The efficient blue and green emission were assigned to $Te_{1}$Tel and $Te_{n}$ (n$\geq$2) cluster bound excitons, respectively. Bright blue (462 nm) and green (535 nm) light emitting diodes (LEDs) have been developed using ZnSSe:Te system as an active layer.

시각적 기능개선을 위한 LED 센서 등기구 설계 (A Design of an LED Sensor Luminaire for Visual Function Improvement)

  • 서정남;유용수;여인선
    • 전기학회논문지
    • /
    • 제59권1호
    • /
    • pp.134-137
    • /
    • 2010
  • An LED sensor luminaire for visual function improvement necessitates the control algorithm for light level adjustment and the appropriate lens design. The control algorithm adapts to surround lighting condition, and thus has the advantages of energy saving and glare reduction. The multi-cell lens design improves color temperature uniformity and spatial light distribution of the luminaire. Experimental and simulated results show that this approach contributes noticeably to energy saving and color temperature uniformity of the LED sensor luminaire.

발진 이론에 근거한 유도결합형 방전광원의 안정기 설계에 관한 연구 (A Study on the Ballast Design of a Inductively Coupled Plasma Light Source based on Oscillation Theory)

  • 김철진;임연찬
    • 전기학회논문지
    • /
    • 제58권6호
    • /
    • pp.1110-1115
    • /
    • 2009
  • We studied on the design of electrical parameters for ICP(Inductively Coupled Plasma) light sources which can be effective to improve the electrical power efficiency of it. These parameters were derivated from Barkhausen theory about the oscillating condition of a ballaster. The relationships of $f-I_p$ and f-n were calculated theoretically and then these relationships were compared with the measured results about $I_p$ and power depending to a discharge length(l) of ICP light source. Finally, we can see that a specific range of induced current depending to a discharge length would be necessary to minimize the change of magnetization inductance and driving frequency at driving.

자동차용 제동등을 위한 FISH-EYE OPTIC 설계에 관한 연구 (A Study on the Design of Fish-Eye Optic for Automotive Stop Light)

  • 임지만;이정환;서명원
    • 한국자동차공학회논문집
    • /
    • 제7권6호
    • /
    • pp.231-240
    • /
    • 1999
  • The most important thing to be considered in designing stop lamps for automobiles is to satisfy the photometric requirement in various countries and achieve the equal image. To meet these requirements, parabolic reflector and fish-eye optics has been widely applied. The form of the embodied optic is most important in satisfying the photometric requirement and achieving the equal image because the impact of fish-eye optic is decisive. In this study, a series of researches has been performed to optimize of the fish-eye optic by analyzing beam pattern through the photometric simulation based on CATAI program. The optimized results have been shown to meet the various photometric requirements including non dazzling condition considering the following car. The methodology of this study is excepted to influence the development procedure of light system. The time and cost for the system development would be greatly saved by suing this simulaion technique.

  • PDF

경승용차용 가솔린 기관의 성능향상에 관한 이론 및 실험적 연구(제1보)- 성능 실험을 중심으로- (An Analytical and Experimental Study on the Improvement of Performances of a Gasoline Engine of the Light Passenger Car (First Paper))

  • 윤건식;서문진;우석근
    • 한국자동차공학회논문집
    • /
    • 제8권6호
    • /
    • pp.40-50
    • /
    • 2000
  • In this study, as a means of increasing engine power, turbocharging was applied to the gasoline engine of a light passenger car which was originally naturally aspirated. Also the catalytic convertor was applied to improve the exhaust emission characteristics. The comparison of the performance characteristics between the burbocharged engine with catalytic convertor and the naturally aspirated engine was made over the wide range of operating conditions. The results showed considerable increase of the output performances at full load condition by trubocharging while slight losses were observed at part load conditions.

  • PDF

A 40-W Flyback Converter with Dual-Operation Modes for Improved Light Load Efficiency

  • Kang, Jin-Gyu;Park, Jeongpyo;Gong, Jung-Chul;Yoo, Changsik
    • JSTS:Journal of Semiconductor Technology and Science
    • /
    • 제15권4호
    • /
    • pp.493-500
    • /
    • 2015
  • A flyback converter operates with either pulse width modulation (PWM) or pulse frequency modulation (PFM) control scheme depending on the load current. At light load condition, PFM control is employed to reduce the switching frequency and thereby minimize the switching power loss. For heavier load, PWM control is used to regulate the output voltage of the flyback converter. The flyback controller has been implemented in a $0.35{\mu}m$ BCDMOS process and applied to a 40-W flyback converter. The light-load power efficiency of the flyback converter is improved up to 5.7-% comparing with the one operating with a fixed switching frequency.