• 제목/요약/키워드: LIGHT

검색결과 31,881건 처리시간 0.048초

Light Quality during Seed Imbibition Affects Germination and Sprout Growth of Soybean

  • Kang, Jin-Ho;Park, A-Jung;Jeon, Byung-Sam;Yoon, Soo-Young;Lee, Sang-Woo
    • 한국작물학회지
    • /
    • 제47권4호
    • /
    • pp.292-296
    • /
    • 2002
  • Soybean seeds were treated with blue, red and far-red lights for 0, 6, 12, and 24 hours during 24-hour imbibition before culture for 6 days. The soybean sprouts raised were classified by their hypocotyl lengths; normal (>4cm), abnormal (<4cm) and non-germination, and their lateral roots, hypocotyl diameters and component dry weights were measured. Red light treatment and dark imbibition reduced the abnormal soybean sprouts more than far-red and blue light treatments, meaning that the former treatments produced more commercial sprouts. The lateral roots were more formed in blue light and dark imbibition than the other light treatments, but were completely blocked by any light treatment lasted during the whole imbibition. Although any light quality treatment did not influence their primary root lengths, blue light one lengthened the hypocotyl more than the others treated during the imbibition, and far-red light enlarged its diameter. Despite this morphological change, component, total or economic yield was not significantly different among the light quality treatments during the imbibition.

Endoreduplication in Phalaenopsis is affected by light quality from light-emitting diodes during somatic embryogenesis

  • Park, So-Young;Yeung, Edward C.;Paek, Kee-Yoeup
    • Plant Biotechnology Reports
    • /
    • 제4권4호
    • /
    • pp.303-309
    • /
    • 2010
  • Endoreduplication is a developmental process that is unique to plants and occurs in all plants. The present study aimed to assess endoreduplication in various explant tissues and regenerated somatic embryos of Doritaenopsis. We further investigated the effects of light quality on endoreduplication and somatic embryo proliferation. To this end, we studied endoreduplication in leaves and root tips from regenerated plantlets and somatic embryos and in developing somatic embryos under 4 types of lighting conditions: red light, red + far-red light, red + blue light, and white light. We found that the degree of endoreduplication varied in different explants, and that the choice of explants used also influenced the ploidy levels of the newly regenerated somatic embryos. The DNA content of the leaf (2C-8C) was less than that of the root tip (2C-16C) and somatic embryo (2C-64C). In terms of light quality, the combination of red and far-red light produced the highest number of somatic embryos, while maintaining a low degree of endoreduplication. The data obtained indicate that this light combination stimulates somatic embryogenesis in Doritaenopsis and may exert some control on endoreduplication during cell division. These findings can be applied to achieve a reduction in somaclonal variations for the purpose of mass proliferation and genetic improvement.

가로등 배광의 실태조사를 통한 조명환경관리구역별 상향광속률 기준 마련을 위한 연구 (A Study on Making Upward Lighting Ratio Regulation for Lighting Zone Based on the Light Distribution of Streetlight Site Survey)

  • 이영진;서영석;오민석;김회서
    • 조명전기설비학회논문지
    • /
    • 제26권10호
    • /
    • pp.9-15
    • /
    • 2012
  • There have been light pollution standards just for architectural lighting and sign in the "Light Pollution Abatement Law" so far. However, both of them regulate only one of the three main light pollution elements-"Glare". Therefore, it is imperative to do research on the other two light pollution elements-"Upward" and "Light Trespass" and make proper restriction. Subsequently, this study focuses on the upward light from the street light and suggests its analysis method. Eventually, this study aims to make viable management which is suitable for the nation and, in addition, to suggest appropriate level of restriction to "Light Pollution Abatement Law" by doing site survey.

저대역 센서 네트워크 기반의 양방향 보안등 관제 시스템 개발 (Development of a Bi-Directional Security Light Control System based on Low-Bandwidth Wireless Sensor Network)

  • 이호근;이상호;이석규;최정원
    • 조명전기설비학회논문지
    • /
    • 제24권10호
    • /
    • pp.58-66
    • /
    • 2010
  • This paper shows an implementation and management result of wireless networks based security light control system, which performs a great role in protection of pedestrians and prevention of crime. Conventional security light units have severe limits in confirmation and inspection of security light unit failure, like wilful damage by someone or failure by influence of other equipment or failure by spontaneous heat-increase, and so on. In addition, local government offices are responsible for maintenance of security light units and as a matter of fact, most of civil complaints are about security light units. It is an obvious that the existing security light maintenance system reaches the limit and the security light maintenance problem is a difficulty of local government. Therefore, efficient security light control system is needed, which enables central control and intelligent maintenance. Moreover, the system has to be easy to control and has to be stable. In this study, wireless sensor network based security light control system is implemented, which is independent of programming language and platform, and which is simple to control and extend the system. The proven protocols, HTTP and SOAP, are utilized in order to improve the system reliability. This paper shows the excellence of our proposed system by implementing and operating it in real environment.

렘브란트, 베르메르, 호퍼의 회화에 나타난 빛과 공간의 비교 분석에 관한 연구 (A Comparative Study on Light and Space in the Paintings of Rembrandt, Vermeer and Hopper)

  • 김종진
    • 한국실내디자인학회논문집
    • /
    • 제18권6호
    • /
    • pp.12-19
    • /
    • 2009
  • The characteristics of light in the paintings of Rembrandt van Rijn, Johaness Vermeer and Edward Hopper are very different. While Rembrandt and Vermeer lived in the 17th century, Hopper lived in the 20th century. Although this time gap, comparative study on their light-space relationship is important because there are spatial similarities as well as light differences. Most three painters' works depict interior spaces with one person inside. The interior space is filled with different light and shadow. In the Rembrandt's paintings, only part of the figure is lit in the ambiguous darkness. In the Vermeer's paintings, the soft indirect light is filled in the domestic space and the boundary between the figure and space is blurred. In the Hopper's paintings, the direct sunlight invades the interior and the figure confronts with strong daylight. These light differences were caused by the artists' intentions as well as the environmental situations. 4 case paintings of each artist were analyzed by phenomenological aspects and computerized light brightness test. Scale models were built to re-construct the three different light characteristics. The model experimentation will have potential to develop 2 dimensional art analysis into 3 dimensional space design by means of light. However it was very difficult to construct the three lights, the experimentation shows they have unique characteristics that can be applied to spatial design studies.

Full-color Non-hogel-based Computer-generated Hologram from Light Field without Color Aberration

  • Min, Dabin;Min, Kyosik;Park, Jae-Hyeung
    • Current Optics and Photonics
    • /
    • 제5권4호
    • /
    • pp.409-420
    • /
    • 2021
  • We propose a method to synthesize a color non-hogel-based computer-generated-hologram (CGH) from light field data of a three-dimensional scene with a hologram pixel pitch shared for all color channels. The non-hogel-based CGH technique generates a continuous wavefront with arbitrary carrier wave from given light field data by interpreting the ray angle in the light field to the spatial frequency of the plane wavefront. The relation between ray angle and spatial frequency is, however, dependent on the wavelength, which leads to different spatial frequency sampling grid in the light field data, resulting in color aberrations in the hologram reconstruction. The proposed method sets a hologram pixel pitch common to all color channels such that the smallest blue diffraction angle covers the field of view of the light field. Then a spatial frequency sampling grid common to all color channels is established by interpolating the light field with the spatial frequency range of the blue wavelength and the sampling interval of the red wavelength. The common hologram pixel pitch and light field spatial frequency sampling grid ensure the synthesis of a color hologram without any color aberrations in the hologram reconstructions, or any loss of information contained in the light field. The proposed method is successfully verified using color light field data of various test or natural 3D scenes.

Use of tar color additives as a light filter to enhance growth and lipid production by the microalga Nannochloropsis gaditana

  • Shin, Won-Sub;Jung, Simon MoonGeun;Cho, Chang-Ho;Woo, Do-Wook;Kim, Woong;Kwon, Jong-Hee
    • Environmental Engineering Research
    • /
    • 제23권2호
    • /
    • pp.205-209
    • /
    • 2018
  • The spectral composition of light can affect the growth and biochemical composition of photosynthetic microalgae. This study examined the use of light filtering through a solution of soluble colored additives, a cost-effective method to alter the light spectrum, on the growth and lipid production of an oleaginous microalga, Nannochloropsis gaditana (N. gaditana). Cells were photoautotrophically cultivated under a white light emitting diode (LED) alone (control) or under a white LED that passed through a solution of red and yellow color additive (4:1 ratio) that blocked light below 600 nm. The specific growth rate was significantly greater under filtered light than white light ($0.2672d^{-1}$ vs. $0.1930d^{-1}$). Growth under filtered light also increased the fatty acid methyl ester (FAME) yield by 22.4% and FAME productivity by 80.0%, relative to the white light control. In addition, the content of saturated fatty acids was greater under filtered light, so the biodiesel products had better stability. These results show that passing white light through an inexpensive color filter can simultaneously enhance cellular growth and lipid productivity of N. gaditana. This approach of optimizing the light spectrum may be applicable to other species of microalgae.

반사율에 따른 광선반 채광 성능평가 연구 - 주거공간을 중심으로 - (Daylighting Performance Evaluation of Light-shelf according to the Reflectivity - Focused on the Residing space -)

  • 허도연;이행우;서장후;김용성
    • KIEAE Journal
    • /
    • 제15권3호
    • /
    • pp.49-56
    • /
    • 2015
  • Purpose: Due to recent increase on energy consumption for light in building, many studies to mitigate this issue have been conducted. Various researches have been carried out to suggest light shelf as one of the solutions, but researches for its reflectivity is very few. In fact, existing research on light shelf shows that utilizing more than 90% of high-illumination materials causes imbalance of glare and illuminance. Method: Therefore this research aimed to evaluate the performance of light shelves depending on reflectivity and to identify proper solution through test-bed. Result: The results are following: 1) Increased reflectivity generally contributed to increase of indoor illuminance but degrade uniformity factor related with indoor comfort of light environment. 2) The $0^{\circ}fixed$ light shelf with 75% of reflectivity and width of 300mm and 40mm appeared to consume more energy than other shelves. Therefore, it is analyzed as unsuitable. 3) This research was conducted by calculating appropriate angle of light shelf around winter and summer solstices and vernal/autumnal equinox. Based on this, performance evaluation was undertaken depending on reflectivity of movable light shelf, which is activated by external sources and can be applied with lower reflectivity than fixed shelf. However, one exception was a movable shelf with width of 600mm that increased light energy consumption when 75% of reflectivity was applied. 4) Performance evaluation of fixed and movable light shelf showed that the shelf with 80% of reflectivity came up with suitable results, but 75% of reflectivity may be applied depending on the width and angle of the shelf. This research is meaningful in that estimation of appropriate reflectivity of light shelf can resolve the glare problem and improve light environment, and further research would be desirable under more diverse conditions to identify proper solution.

Lanthanide-Cored Supramolecular Systems with Highly Efficient Light-Harvesting Dendritic Arrays towards Tomorrow′s Information Technology

  • Kim, Hwan-Kyu;Roh, Soo-Gyun;Hong, Kyong-Soo;Ka, Jae-Won;Baek, Nam-Seob;Oh, Jae-Buem;Nah, Min-Kook;Cha, Yun-Hui;Jin Ko
    • Macromolecular Research
    • /
    • 제11권3호
    • /
    • pp.133-145
    • /
    • 2003
  • We have developed novel lanthanide-cored supramolecular systems with highly efficient light-harvesting dendritic arrays for integrated planar waveguide-typed amplifiers. Er$^{3+}$ ions were encapsulated by the supramolecular ligands, such as porphyrins and macrobicyclics. The supramolecular ligands have been designed and synthesized to provide enough coordination sites for the formation of stable Er(III)-chelated complexes. For getting a higher optical amplification gain, also, the energy levels of the supramolecular ligands were tailored to maintain the effective energy transfer process from supramolecular ligands to erbium(III) ions. Furthermore, to maximize the light-harvesting effect, new aryl ether-functionalized dendrons as photon antennas have been incorporated into lanthanide-cored supramolecular systems. In this paper, molecular design, synthesis and luminescent properties of novel lanthanide-cored integrated supramolecular systems with highly efficient light-harvesting dendritic arrays will be discussed.d.

확산필름 부착 위치에 따른 광선반 성능개선 연구 (Research of the Performance Improvement of a Light Shelf Depending on the Diffusion Film Installation Position)

  • 박은수;이행우;송석재;김용성
    • KIEAE Journal
    • /
    • 제17권3호
    • /
    • pp.91-97
    • /
    • 2017
  • Purpose: Various studies on a light shelf are in progress, but it has the problem of glare occurrence. The present study suggested a diffusion film as the method for resolving the glare problem, and aimed to establish light shelf-related basic data by conducting the performance evaluation of a light shelf depending on the installation position of the diffusion film. Method: To carry out the light shelf performance evaluation depending on the diffusion film installation position, three cases were established: no diffusion film installation (Case 1), diffusion film installation on the reflector (Case 2), and diffusion film installation on the upper glass surface of the window for light shelf installation (Case 3); and the energy reduction performance, luminance, and luminance contrast were analyzed based on a testbed. Result: The conclusions of this study are as follows. 1) When the diffusion film was applied, the amount of light introduced through the light shelf decreased, and the average indoor illumination decreased accordingly. 2) For Case 3, the lighting energy reduction performance was identical to the lighting energy reduction efficiency of the existing light shelf; and for Case 2, it was found to be inappropriate as the lighting energy consumption increased compared to that of the existing light shelf. 3) The analysis of the glare for the cases established in this study showed that the luminance contrast was low for Case 3, and thus the glare problem could be minimized. 4) The specific angle of the light shelf could induce the glare problem by increasing the luminance depending on the external condition. 5) Based on the aforementioned contents, the installation position of the diffusion film for improving the lighting performance and glare problem of the light shelf was found to be the upper glass surface of the window for light shelf installation.