• 제목/요약/키워드: Down Light

검색결과 469건 처리시간 0.026초

공기주입형 의복의 보온력 측정 및 다운재킷의 보온력과의 비교 (Comparisons of Thermal Insulations between on Air-Cell Pack Embedded Jacket and Down Jackets)

  • 김영빈;장원;김기림;김시연;백윤정;이주영
    • 한국의류학회지
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    • 제39권1호
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    • pp.55-62
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    • 2015
  • This study investigated the thermal insulation of an air-cell pack embedded jacket and down jackets to understand the potential of air-cell pack as a filler for winter outdoor wear. A thermal manikin measured the thermal insulation of the following jackets: HD (heavy down jacket, total weight (Tw) 750g, goose down weight (Dw) 350g), LD (light down jacket, Tw 560g, Dw 140g), AF (air-cell pack embedded jacket, Tw 490g, trunk goose down in LD was replaced to air cell), F (film jacket, Tw 469g, but removed the air in the air-cell pack from the AF), and Control (control jacket, Tw 438g, removed the air-cell pack film from the F). Thermal insulations of each experimental condition were measured in a static standing posture. Total thermal insulations (IT) were 1.29clo (HD), 1.23clo (LD), 1.16clo (AF), 1.20clo (F), and 1.08clo (Control). Body regional thermal insulation was higher in the chest and back than in the abdomen and hip in all conditions. The results suggest that an economical and versatile outdoor jacket with superior thermal insulation will be feasible if the air volume is properly controlled in air-cell pack embedded jackets in consideration of regional different distribution and used in combination with film and down.

LIGHT-DEPENDENT CHANGES OF CHLOROPHYLL FLUORESCENCE AND XANTHOPHYLL CYCLE PIGMENTS IN MAIZE LEAVES DURING DESICCATION

  • Xu, Chang-Cheng;Lee, Choon-Hwan;Zou, Qi
    • Journal of Photoscience
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    • 제5권1호
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    • pp.17-22
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    • 1998
  • Changes of chlorophyll fluorescence and xanthophyll cycle pigment contents in maize leaves were investigated dunng desiccation in darkness or in the light. In darkness, a drastic dehydration of detached maize leaves down to 50% relative water content (RWC) affected photochemical efficiency of photosystem II (Fv/Fm) and pht)tochemical quenching (qP) only slightly. In contrast, desiccation in the light with a moderate intensity led to a pronounced reduction in Fv/Fm with a Fo quenching when RWC was greater than 70%. This reduction in Fv/Fm could be recovered in darkness under hutrod condition. In leaves with RWC below 70%, significant reduction in Fv/Fm was accompanied by an increase of Fo, which could not be reversed within 5 h in darkness under humid condition. The nonphotochemical quenching increased during desiccation in the light with a concomitant rise in zeaxanthin at the expense of violaxanthin. Pretreatment with dithiothreitol (DTT), an inhibitor of zeaxanthin synthesis, inhibited the development of nonphotochemical quenching and prevented the xanthophyll interconversion during desiccation in the light. These results suggest that even light with a moderate intensity becomes excessive under dehydration and zeaxanthin-associated photoprotection of photosynthetic apparatus against photodamage is involved, but the protection is not complete against severe desiccation.

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양자 정보 기술을 위한 양자 광원 연구 동향 (Research Trend of Quantum Light Source for Quantum Information Technology)

  • 고영호;김갑중;최병석;한원석;윤천주;주정진
    • 전자통신동향분석
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    • 제34권5호
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    • pp.99-112
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    • 2019
  • A quantum light source is an essential element for quantum information technology, including quantum communication, quantum sensor, and quantum computer. Quantum light sources including photon number state, entangled state, and squeezed state can be divided into two types according to the generation mechanism, namely single emitter and non-linear based systems. The single emitter platform contains atom/ion trap, solid-state defect/color center, two-dimensional material, and semiconductor quantum dot, which can emit deterministic photons. The non-linear based platform contains spontaneous parametric down-conversion and spontaneous four-wave mixing, which can emit probabilistic photon pairs. For each platform, we give an overview of the recent research trends of the generation, manipulation, and integration of single photon and entangled photon sources. The characteristics of quantum light sources are investigated for each platform. In addition, we briefly introduce quantum sensing, quantum communication, and quantum computing applications based on quantum light sources. We discuss the challenges and prospects of quantum light sources for quantum information technology.

식물공장의 LED 광강도 변화에 따른 식물성장 변화에 관한 연구 (Study on the Plant Growth Variation According to Change of Luminous Flux LED Light in Plant Factory)

  • 홍지완
    • 한국산학기술학회논문지
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    • 제21권3호
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    • pp.304-311
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    • 2020
  • 본 연구는 식물공장 요소 기술의 표준화를 위하여 LED 광원의 광강도에 따른 식물의 성장변화와 최적 LED 광강도 범위를 확인하였다. 1400 lx와 1600 lx 영역에서 비교적 안정적인 성장을 확인하였고 광강도 증가에 따라 성장과 둔화가 반복되며 성장을 지속하지만, 잎의 성장이 없으면 웃자라는 현상과 함께 성장은 둔화하는 것이 확인되었다. 400 lx에서 800 lx까지의 성장 특징은 실험 기간 어느 정도 성장이 지속하였지만, 웃자라는 현상은 7일까지 유지되었고, 잎이 성장하지 않아 일간 평균 성장차가 현저히 낮아진다는 것을 확인하였다. 1,000 lx에서 1,400 lx까지의 성장은 광강도가 높아짐에 따라 잎의 성장과 일별 성장이 확인되었고 성장증가와 성장둔화가 반복되는 것이 확인되었다. 1,600 lx와 1,800 lx는 1,400 lx 영역과 유사한 성장을 보였지만, 잎의 성장은 높았다. 그러나 1,800 lx에서는 1,400 lx보다 높은 성장을 보였고, 시간 경과에 따라 성장이 둔화하는 것이 확인되었다. 또한, 광강도가 강할수록 광원으로부터 발산되는 열로 인하여 식물 주변의 온도상승이 수반되어 잎의 열화현상이 발생한다. 이러한 실험 결과를 토대로 식물의 성장에 따른 재배 트레이의 공간설정과 재배용 광원과의 거리 조절이 필요하며, 광원의 최대강도 사용에 따른 재배공간의 능동적인 공기조화 계획이 필요하다.

에너지 저감을 위한 주거공간 내 위치인식기술 적용 광선반 시스템 개발연구 (A Study on Light-Shelf System using Location-Awareness Technology for Energy Saving in Residential Space)

  • 김상훈;김용성;이행우;서장후
    • 설비공학논문집
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    • 제26권6호
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    • pp.275-286
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    • 2014
  • Light shelf is an efficient system that reduces the energy consumption by bringing the natural light down to the deep spaces inside of a building. However, the existing light shelves have limits in reducing energy usage, because the direction of the light flow is determined by the external environment such as the altitude of the sun and the azimuth. This current study presents a system that increases the efficiency of the light shelf by applying the Location-Awareness technology, in which the efficiency was verified through the performance evaluation. According to the examination of the technology for the Location-Awareness within residential space, 'Zigbee' type appears to be the most appropriate. The Location-Awareness technology operates the light shelf based on both the angle control axis and the light shelf angle control axis through the modularization of the reflector surface which is less affected by the external environment. The results of the performance evaluation showed that the movable light shelf that employs the Location-Awareness technology can reduce the energy consumption for lighting by 98.3% compared to the fixed light shelf and by 97.3% compared to the movable light shelf without Location-Awareness.

개선된 DSM 기법을 통한 경전철 정거장 기능실의 슬림화에 관한 연구 (On Slimming down the Functions Room of Light Rail Transit Stations by Utilizing an Enhanced DSM Method)

  • 김주욱;박기준;김영민;이재천
    • 한국산학기술학회논문지
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    • 제16권2호
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    • pp.927-939
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    • 2015
  • 오늘날 산업 기술의 발달에 따른 고도화로 인해, 고속철도로 대변되는 전국망 철도 운영과 함께, 도시 내 또는 교외의 단거리 구간을 운영하는 철도사업에 관심이 증대되고 있다. 특히, 일반철도라 불리는 기존의 중전철에 비해서, 후자의 경우는 단거리 운행에 따른 특성으로 경량전철의 형태로서, 보다 작은 규모의 철도차량 및 역사(정거장)으로 운영이 가능할 것으로 기대되고 있다. 또한 철도차량의 무인화 운행 및 정거장 운영 인력의 감축도 주요 관심사로 부상하고 있다. 하지만, 경량전철시스템의 기반 시설인 역사의 경우, 시설을 시공하는데 있어서 기존의 중전철의 설계지침 및 관련법에 의해 건설되고 있다. 따라서 이러한 지침에 의해 건설되는 역사는 소형화의 추구 방향과는 거리가 있게 된다. 경량전철 역사의 슬림화 목적을 달성하기 위해서는 단순히 건축학적 의미 이상의 접근이 필요하다. 왜냐하면 경량전철은 다양한 시스템이 내재된 복합구조의 시스템이기 때문이다. 따라서, 역사의 슬림화를 추구하면서 열차무인운행에 대한 안전성까지 확보하기 위해서는 시스템 설계에서 체계적인 접근이 필요하다. 특히, 경전철 역사에 대한 설계지침 및 관련법이 국내에 현재까지는 없는 실정이다. 이러한 문제점을 해결하기 위해 본 연구에서는 역사 기능실의 소형화에 대한 연구를 수행하였다. 구체적으로 설계구조행렬(DSM)의 개선된 기법을 제안하였으며, 이의 적용을 통해 역사 기능실 구조설계에서 구성품 통합에 의한 소형화 방법을 연구하였다. 본 연구에서 제안하는 기법을 기반으로 경전철 역사의 기능실 통합을 통한 슬림화 설계를 수행한다면, 향후 경전철역사 건설에서 상당한 시간, 공간, 예산 절감 등의 효과가 기대된다.

키토산 가교 처리된 면직물의 천연염색에 관한 연구(III) - 황벽을 중심으로 - (Natural Dyeing of Chitosan Crossinked Cotton Fabrics(III) - Amur cork tree -)

  • 곽미정;이신희
    • 한국의류산업학회지
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    • 제10권4호
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    • pp.544-551
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    • 2008
  • In this study, the colorants of Amur cork tree were extracted with boiling water. Chitosan crosslinked cotton fabrics have been dyed with aqueous extract of Amur cork tree and their dyeabilities on the fabrics were studied. Additionally the fastness to washing and light were also investigated. Cotton fabrics were treated with a crosslinking agent epichlorohydrin in the presence of chitosan to provide the cotton fabrics the dyeing properties of natural dye(Amur cork tree) by the chemical linking of chitosan to the cellulose structure. This process was applied by means of the conventional mercerizing process. The chitosan finishing and durable press finishing of the cotton fabrics occurred simultaneously in the mercerization bath. On the surface color change, the fabric of no-chitosan finished and no-mordanted has greenish yellow. The more crosslinked chitosan on cotton fabrics has the more turned down greenish on the surface color, as increasing the concentration of chitosan, greenish color turn down to the yellow close the 90o hue angle. In all sorts of fabrics, dyeability(K/S) is slightly affected by the number of manufacturing process and the concentration of chitosan. But only mercerized cotton fabric has higher dyeability (K/S) than mordant treated cotton fabrics. Wash fastness has little different results by each condition, but almost similar values. Light fastness was improved with chitosan treatment on cotton fabric.

레이저 슬릿빔과 CCD 카메라를 이용한 3차원 영상인식 (3D image processing using laser slit beam and CCD camera)

  • 김동기;윤광의;강이석
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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    • pp.40-43
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    • 1997
  • This paper presents a 3D object recognition method for generation of 3D environmental map or obstacle recognition of mobile robots. An active light source projects a stripe pattern of light onto the object surface, while the camera observes the projected pattern from its offset point. The system consists of a laser unit and a camera on a pan/tilt device. The line segment in 2D camera image implies an object surface plane. The scaling, filtering, edge extraction, object extraction and line thinning are used for the enhancement of the light stripe image. We can get faithful depth informations of the object surface from the line segment interpretation. The performance of the proposed method has demonstrated in detail through the experiments for varies type objects. Experimental results show that the method has a good position accuracy, effectively eliminates optical noises in the image, greatly reduces memory requirement, and also greatly cut down the image processing time for the 3D object recognition compared to the conventional object recognition.

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가로등 전용 누전 개폐기의 차단효과에 대한 고찰 (Characteristics of Street Lamp Controller with Earth Leakage Contactor)

  • 이성재;신재식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2010년도 하계학술대회 논문집
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    • pp.283-283
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    • 2010
  • Smart street light controller is a product with advance micro controller base for energy saving in conventional street lighting systems. Intelligent Street light controller are specially developed for automation and energy saving in conventional street light systems and lighting systems. It is so designed that it operates on sunrise & sun set timings according to longitude of particular location with facilitate to set month wise civil twilight timings to cope up with all seasons. Dimming (Power down) mode selection switch on/off at fixed times with relay or contactor. Night dimming, staggering and intelligent control reduces burn hours and increases the lifetime of lamps with about 30% and low annual operating cost type base are among the most inexpensive wireless technologies available. Low initial costs As PLC wireless, there is no need to establish cable connection.

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SPHEREx를 활용한 태양계 연구 (Solar System Sciences with SPHEREx)

  • 표정현;정웅섭
    • 천문학회보
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    • 제43권1호
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    • pp.48.2-48.2
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    • 2018
  • SPHEREx is expected to provide us with the opportunity of unbiased sampling of small Solar System objects along with near-infrared ($0.75-5.0{\mu}m$) spectroscopic (R ~ 41) information. The estimated numbers of detections are tens of thousands for asteroids, thousands for Trojans, hundreds for comets, and several for Kuiper Belt Objects, Centaurs and Scattered Disk Objects. Wide spectral range covering many bands from carbon-bearing molecules and ices will enable us to systematically survey the volatile materials throughout the Solar System. SPHEREx will, for the first time, produce the near-infrared spectral map of the zodiacal light to pin-down the relative contributions of various populations of Solar System objects and interstellar dust to the dust grains in the interplanetary space. The study of the zodiacal light is also important to remove the foreground for the EBL (extragalactic background light) study, one of the main topics of the mission.

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