• 제목/요약/키워드: Light quality

검색결과 2,306건 처리시간 0.035초

식물 생장 조절을 위한 LED 광처리 장치에 대한 연구 (LED for plant growth regulators for the study of Light on the device)

  • 방걸원;김용호
    • 디지털융복합연구
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    • 제10권7호
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    • pp.267-272
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    • 2012
  • 열악한 광환경의 극복은 원예작물의 생육증대는 물론 고품질 생산에 있어서도 매우 중요한 역할을 할 수 있는데 이때 LED 광시스템을 이용할 경우 광합성산물의 소모를 효과적으로 줄일 수 있게 된다. 따라서 본 연구에서는 농가 비닐하우스의 저효율, 재배연차별 경영비 상승에 따른 소득감소를 개선하고 적정한 작물생육을 유도함으로써 공장형 식물재배 환경을 마련함과 동시에 농가 소득 증대에 기여할 수 있을 것이며 LED 광처리 장치를 이용한 보광을 통해 광합성 촉진 및 생산물의 품질 향상, 식물 생장 조절이 가능할 것으로 판단되며 이를 위한 효율적 LED 광처리 장치를 개발하고 LED 광처리장치를 이용하여 잎상추를 재배한 결과 일반 형광등이나 백열전구에서 재배한 것 보다 성장 속도가 향상된 것을 알 수 있다. 보통 잎상추는 육묘에서 출하까지 수확까지 25일 ~ 30일 걸린데 반해 광처리장치의 적색광(파장:645nm)을 이용하여 재배한 잎상추는 7일 만에 수확할 수 있을 정도로 성장속도가 증가하였다. 또한 적색광(파장:645nm)과 청색광(파장:470nm)을 동시에 점등하여 재배한 칸에서는 5일만에 수확할 수 있을 정도로 빠른 성장속도를 보였다.

국내 유통 중인 석유제품 내 석유계 총 탄화수소화합물(TPH) 분석 (Analysis of Total Petroleum Hydrocarbon in Domestic Distribution Petroleum)

  • 임영관;김정민;김종렬;권민정;이경흠;류승현
    • 공업화학
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    • 제27권5호
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    • pp.546-550
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    • 2016
  • 국내 토양오염의 60~70% 이상이 석유제품에 의한 오염이며, 석유제품에 의해 토양오염이 발생될 경우, 토양환경보전법 상 B T E X와 total petroleum hydrocarbon (TPH)를 분석하도록 명시하고 있다. 본 연구에서는 국내 유통 중인 석유제품에 대한 구간별 TPH 패턴을 분석하였다. 또한 $C_8{\sim}C_{40}$ 구간만을 분석하는 현행 토양오염공정시험기준의 문제점을 보완하여 석유제품 내 TPH를 정량분석 하였다. 분석결과, 토양오염공정시험기준 분석조건으로 분석한 결과값과 보완된 분석방법을 이용했을 시, 휘발유와 용제 1호 같은 저비점 유류의 경우, 최대 85%의 차이가 발생하는 것을 확인하였다.

Heterologous Expression and Characterization of a Novel Exo-Polygalacturonase from Aspergillus fumigatus Af293 and Its Application in Juice Extraction

  • Chengwei Yang;Ting Zhang;Jing Zhu;Yunyi Wei;Furong Zhu;Zhong Cheng
    • Journal of Microbiology and Biotechnology
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    • 제33권4호
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    • pp.533-542
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    • 2023
  • Exo-polygalacturonase (exo-PG) hydrolyzes pectin acids and liberates mono-galacturonate, which plays an important role in juice extraction, and has rarely been reported. Exo-PG (AfumExoPG28A) from Aspergillus fumigatus belongs to the glycoside hydrolase 28 family. In this study, its gene was cloned and the protein was expressed and secreted in Pichia pastoris with a maximal activity of 4.44 U/ml. The optimal temperature and pH of AfumExoPG28A were 55℃ and 4.0, respectively. The enzyme exhibited activity over almost the entire acidic pH range (>20.0% activity at pH 2.5-6.5) and remained stable at pH 2.5-10.0 for 24 h. The Km and Vmax values of AfumExoPG28A were calculated by the substrate of polygalacturonic acid as 25.4 mg/ml and 23.6 U/mg, respectively. Addition of AfumExoPG28A (0.8 U/mg) increased the light transmittance and juice yield of plantain pulp by 11.7% and 9%, respectively. Combining AfumExoPG28A (0.8 U/mg) with an endo-PG (0.8 U/mg) from our laboratory, the enzymes increased the light transmittance and juice yield of plantain pulp by 45.7% and 10%, respectively. Thus, the enzyme's potential value in juice production was revealed by the remarkable acidic properties and catalytic activity in fruit pulp.

LED 선박용 항해등의 저온에서의 신뢰성 방안 (Reliable methods at low temperatures for LED navigation light of ships)

  • 양병문;차재상
    • 한국위성정보통신학회논문지
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    • 제10권1호
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    • pp.83-87
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    • 2015
  • 선박에 설치되는 항해등은 해상교통 수단으로 상호간의 충돌을 사전에 예방하고 안전을 확보하는데 아주 중요한 역할을 한다. 항해등의 사용은 주로 야간에 사용되며, 주간일지라도 강우, 연기 등에 의하여 제한된 시정 내에서는 사용되어야 하며, 특히 국제해상충돌예방규칙(COLREG)의 항해 규정을 잘 이해하고 정확하게 파악하여 설치되어야 한다. 선박용 항해등(Masthead)제품의 구성은 LED 모듈, 콘트롤 보드, 컨버터, 프레넬 렌즈, 외함 등으로 구성된다. 현재 대우조선해양에서 건조하여 납품되는 선박 중 러시아 선급(RMRS)에서 항해등의 사용 환경이 $-52^{\circ}C$ 이하에서 신뢰성이 보증된 제품을 요구하고 있다. 기존의 LED 항해등은 $-25{\sim}40^{\circ}C$에서 품질을 보증하고 있으며, 저온에서 발생할 수 있는 전자부품의 우발고장이나 장시간 운용 시 발생할 수 있는 신뢰성 저하문제에 대한 검증이 시급한 상황이다. 따라서 본 연구는 지금까지의 신뢰성 현황과 앞으로 방안을 제시하고자 한다.

Supplementary Blue and Red Radiation at Sunrise and Sunset Influences Growth of Ageratum, African Marigold, and Salvia Plants

  • Heo, Jeong-Wook;Lee, Yong-Beom;Bang, Hea-Son;Hong, Seung-Gil;Kang, Kee-Kyung
    • 한국환경농학회지
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    • 제30권4호
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    • pp.382-389
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    • 2011
  • BACKGROUND: Light-emitting diodes (LEDs) with lower electric cost and the specific wavelength have been considering as a novel light source for plant production in greenhouse conditions as well as in a closed culture system. Supplementary lighting for day-length extension was considered as light intensity, light quality, and/or photoperiod control on plant growth and development. Effects of supplementary blue or red LED radiation with lower light intensity on growth of Ageratum (Ageratum houstonianum Mill., cv. Blue Field), African marigold (Tagetes erecta L., cv. Orange Boy), and Salvia (Salvia splendens F. Sello ex Ruem & Schult., cv. Red Vista) were discussed during sunrise and sunset twilight in the experiment. METHODS AND RESULTS: Supplementary lighting by blue and red LEDs for 30 (Treatment B30; R30) or 60 (Treatment B60; R60) min. per day were established in greenhouse conditions. Photosynthetic photon flux for supplementary radiation was kept at $15{\mu}mol\;m^{-2}\;s^{-1}$ on the culture bed. Natural condition without supplementary light was considered as a control. The highest shoot and root dry weights were shown in African marigold exposed by red light for 60 min. per day. Supplementary blue and red lighting regardless of the radiation time significantly stimulated development of lateral branches in African marigold. Stem growth in Ageratum and Salvia seedlings was significantly promoted by red radiation as well as natural light. CONCLUSIONS: Extending of the radiation time at sunrise and sunset twilight using LEDs stimulated reproductive growth of flowering plant species. Different characteristics on growth under supplementary blue or red lighting conditions were also observed in the seedlings during supplementary radiation.

Effects of light-emitting diodes on protoplast regeneration from gametophytic cells of the commercial kelp Undaria pinnatifida (Laminariales, Phaeophyceae)

  • Avila-Peltroche, Jose;Won, Boo Yeon;Cho, Tae Oh
    • ALGAE
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    • 제37권2호
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    • pp.163-174
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    • 2022
  • Light-emitting-diodes (LEDs) are a lighting source useful for the precise evaluation of light quality effect on biological systems. Despite the importance of light spectra on the regeneration of land plant protoplasts ("naked cells"), this factor has not been tested yet on protoplasts from multicellular algae. This study reports on the effects of pure primary colors (red, blue, and green), dichromatic (red plus blue, RB, 1 : 2) and white LEDs on protoplast regeneration from male and female Undaria pinnatifida gametophytes. We also evaluated the effect of different light spectra on pigment composition (chlorophyll a, chlorophyll c, and fucoxanthine), and the light intensities under the best condition on the regeneration process. In the early stages, blue or RB LEDs increased the percentage of dividing female protoplasts, whereas red, blue, and RB LEDs enhanced that of dividing male protoplasts. In the later stages, RB LEDs showed a positive effect only on the percentage of multiple rhizoid-like protrusions (male gametophyte). They also increased the final area of both regenerated gametophytes. The LEDs did not affect pigment composition in female gametophytes. In male gametophytes, in contrast, they reduced chlorophyll c, while blue, RB, and green LEDs decreased fucoxanthin. Under RB LEDs, the optimal light intensity was 80 µmol photons m-2 s-1 for female gametophytes and 40 to 60 µmol photons m-2 s-1 for male gametophytes. Our results suggest that dichromatic LED illumination (red-blue) improves regeneration of U. pinnatifida gametophyte-isolated protoplasts. Thus, dichromatic LEDs might a suitable light source for enhancing protoplast regeneration in brown seaweeds.

디지털 카메라에서 컬러 필터 어레이를 위한 평가 시스템 (Evaluation System for Color Filter Array (CFA) in Digital Camera)

  • 배태욱
    • 한국멀티미디어학회논문지
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    • 제20권11호
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    • pp.1741-1749
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    • 2017
  • In commercial digital-cameras, color-filter filters light according to wavelength range of color filter array (CFA) and the filtered intensities contain color information of light. Then, output data of CFA is transformed to final rendered image through demosaicing process. In image processing of digital-camera, the quality of the final rendered image is affected by optical cross talk of CFA, kind of CFA pattern etc. Basically, pattern of CFA plays important role in image quality of final image rendered by digital-camera. Therefore, an evaluation system capable of quantitatively evaluating CFA is needed. This paper proposes a novel evaluation system using existing and proposed image metrics for evaluating CFAs of digital-camera. Proposed CFA evaluation system consist of color difference in CIELAB and S-CIELAB, Structure SImilarity (SSIM), MTF50, moire starting point (MSP), and subjective preference (SP). MSP and SP are newly designed for the proposed evaluation system. Proposed evaluation system is expressed in polar coordinates to analyze the characteristics of CFA objectively and intuitively. Through simulations, we confirmed that proposed CFA evaluation system can objectively assess performance of developed CFAs.

프레임 차와 톤 매핑을 이용한 저조도 영상 향상 (Low-light Image Enhancement Based on Frame Difference and Tone Mapping)

  • 정윤주;이영학;심재창;정순기
    • 한국멀티미디어학회논문지
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    • 제21권9호
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    • pp.1044-1051
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    • 2018
  • In this paper, we propose a new method to improve low light image. In order to improve the image quality of a night image with a moving object as much as the quality of a daytime image, the following tasks were performed. Firstly, we reduce the noisy of the input night image and improve the night image by the tone mapping method. Secondly, we segment the input night image into a foreground with motion and a background without motion. The motion is detected using both the difference between the current frame and the previous frame and the difference between the current frame and the night background image. The background region of the night image takes pixels from corresponding positions in the daytime image. The foreground regions of the night image take the pixels from the corresponding positions of the image which is improved by the tone mapping method. Experimental results show that the proposed method can improve the visual quality more clearly than the existing methods.

병원건축의 친환경 성능 향상을 위한 국내외 친환경 건축물 평가항목의 비교 연구 (A Comparative Study of a Domestic and Foreign Green Architecture Evaluation Items for a Green Performance Enhancement of Hospital Architecture)

  • 이호성
    • 한국실내디자인학회논문집
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    • 제18권1호
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    • pp.99-107
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    • 2009
  • In order to prepare future green hospital architecture authentication system, this study is a comparative year report to Korean, the United States, Japanese, British, Canadian and Australian green building authentication systems. Also, the United States and Australian Green hospital authentication systems were examined, and the authentication items of hospitals were compared with those of civil architecture. Though the examination and analysis, the portion of indoor environmental quality section commonly shows the average of 20.7 percent in all 6 countries. Especially, IAQ(Indoor Air Quality) among inside IEQ(Indoor Environment Quality) is overwhelmingly much treated in Korea, the U.S.A, Canada and Australia. In Japan, heat, light and sound are the important factors for authentication evaluation, while in the U.K light are more emphasized for the authentication. 'LEED for Healthcare' as a hospital evaluation authentication system subdivided currently most. The system includes the detailed and extensive evaluation items ranging from hospital management, traffic, emission, water resources utilization to integrated design and furnishing. These overseas systems should be carefully investigated, researched and analyzed for an appropriate improvement of domestic green hospital authentication system. Also the current evaluation method of IEQ section of Korean GBCC needs to be modified. That's why the method puts too much importance on IAQ in IEQ section.