• 제목/요약/키워드: Light Well

검색결과 3,379건 처리시간 0.032초

Photoelectric Observations of the Close Eclipsing Binary System CW Cephei

  • Han, Won-Yong
    • Journal of Astronomy and Space Sciences
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    • 제1권1호
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    • pp.41-53
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    • 1984
  • Photoelectric observations of the close eclipsing binary system CW Cep, which is well known of its apsidal motion, were made on 20 nights during August and November in 1983 using two 61cm reflectors at the Sobaeksan Observing Station of Korean National Astronomical Observatory and I1san Observing Station of Yonsei University Observatory. Standardized new light curves in UBV system are presented with a total of 1,422 individual observations. For the corrections of regional and instrumental differences, same standard stars were observed at the two observatories. Four new times of minimum light were determined with the method of Kwee and van Woerden(1956). With all of the collected times of minima, apsidal motion of this system was checked, but the O-C values calculated by the light elements of Nha(1975) and Soderhjelm (1976) did not coincide well with new times of minima. New light elements which satisfy most times of minima better, and are deduced the apsidal period derived by the new light elements turns out to be 43 years, somewhat longer than those of values previously known.

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속 빈 레이저 빔을 이용한 원자 가이드 (Hollow Beam Atom Tunnel)

  • 송연호
    • 한국광학회:학술대회논문집
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    • 한국광학회 2000년도 제11회 정기총회 및 00년 동계학술발표회 논문집
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    • pp.130-131
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    • 2000
  • One of the more promising proposals for guiding and focusing neutral atoms involves dark hollow laser beams. When the frequency of the laser is detuned to the blue of resonance, the dipole force the atoms feel in the light confines them to the dark core where the atoms can be transported with minimal interaction with the light. The ability of the all-light atom guides to transport large number of ultracold atoms for long distances without physical walls leads to the possibility of a versatile tool for atom lithography, atom interferometry, atomic spectroscopy as well as for transporting and manipulating Bose-Einstein condensates. Furthermore since the atoms transported in all-light atom guides do not come into contact with matter, they can in principle be used to transport antimatter as well. The ability to vary the core size of the hollow beam makes the all-light atom guide potentially useful for focusing neutral atoms. The atoms could be focused as tight as the core size of the hollow beam at its waist. This new focusing scheme, called the atom funnel, would not show spherical and chromatic aberrations that conventional harmonic focusing suffers from. (omitted)

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빛에 의한 식물 유전자의 발현 (Light Regulated Plant Gene Expression)

  • 한태룡
    • 한국식물학회:학술대회논문집
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    • 한국식물학회 1987년도 식물생명공학 심포지움 논문집 Proceedings of Symposia on Plant Biotechnology
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    • pp.63-79
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    • 1987
  • Light regulates a variety of genes in higher plants. The expression of light-induced plant genes is regulated at the level of transcription via red- light photomorphogenic receptor, phytochrome, as well as unknown blue light photoreceptor(s). Ribulose-5-phosphate carboxylase/oxygenase (Rubisco) small subunit (SSB) and light harvesting chlorophyll a/b (Cab) protein are those of the best understood genes regulated by light. 5'-upstream flanking sequence (- -400) of Rubisco SSB and Cab genes sis known as a light responsive, enhance-like element. It responses to red and blue light in transgenic plant system as a tissue specific manner. Phytochrome gene is also regulated by light. In contrast to most of the light regulated plant genes, it is negatively controlled by red light. Search for the cis- and trans-acting factors responsible for the light signal is in progress to understant photomorphogenesis and development in higher plants.

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PHYSIOLOGICAL RESPONSE OF PANAX GINSENG TO LIGHT

  • Park Hoon
    • 고려인삼학회:학술대회논문집
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    • 고려인삼학회 1980년도 학술대회지
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    • pp.151-170
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    • 1980
  • Physiological response of Panax ginseng var. atropurpureacaulo (purple stem variety, Pg) to light was reviewed through old literatures and recent experiments. Canopy structure, growth, pigment, leaf anatomy, disease occurence, transpiration, photosynthesis (PS), leaf saponin, photoperiodism and nutrient uptake were concerned. P. ginseng var. xanthocarpus (yellow berry variety, Px) and Panax quinquefolius(Pq) were compared with Pg if possible. Compensation point(Cp) increased with increase of light and ranged from 110 to 150 at $20^{\circ}C$ but from 140 to 220 at $30^{\circ}C$ with 4 to 15 Klux indicating occurence of light and temperature-dependent high photorespiration. Characteristics of Korea ginseng to hate high temperature was well accordance with an observation 2000 years ago. Korea ginseng showed lower Cp and appeared to be more tolerant to high light intensity and temperature than American sheng although the latter showed greater PS, stomata frequency and conductance, chlorophyll and carotenoids. Px showed lower PS than Pg probably due to higher Cp. Total leaf saponin was higher in leaves grown under high light. Ratio or diol saponin and triol saponin(PT/PD) decreased with increase of light intensity during growing mainly due to decrease of ginsenoside $Rg_1$ but increase of ginsenoside Rd. Leaves of Pg and Px had $Rg_1$ but no $Rb_3$ which was only found as much as $20\%$ of total in Pq leaves, and decreased with increase of light intensity. Re increased in Pg and Px but decreased in Pq with increase of light. PT/PD in leaf ranged 1.0-1.5 in Pg and Px but around 0.5 in Pq. Korea ginseng has Yang characteristics(tolerant to high light and temperature), cultured under Eum(shade) condition and long been used for Yang efficacy (to build up energy) while Pq was quite contrary. Traditional low light $intensity(3-8\%)$ for Korea ginseng culture appeared to be strongly related to historical unique quality. Effect of light quality and photoperiodism was not well known. Experiences are long but scientific knowledge is short for production and quality assessment of ginseng. Recent scientific knowledge of ginseng should learn wisdom from old experiences.

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치매요양시설에서의 치료를 위한 빛·색채의 시설적 적용 특성에 관한 고찰 - 정성적 및 정량적 적용 특성을 중심으로 (A Study on the Characteristics of Application for Therapeutic Light and Color in Dementia Care Facilities - Focused on Qualitative and Quantitative Application Characteristics)

  • 지수인
    • 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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    • 제24권4호
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    • pp.69-87
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    • 2018
  • Purpose: This study has been started with the awareness that light and color are the main visual sensors of the multi-sensory stimulation environment to achieve the therapeutic environment for demented elderly. The purpose of this study therefore is for clarifying the application characteristics of therapeutic light and color for dementia care facilities. Methods: Internal and external literature reviews have been conducted for the investigation into a)disorders and visual system in demented elderly, b)therapeutic effects of light and color, c)heliotherapy, light therapy and color therapy to deduce the therapeutic characteristics of light and color for demented elderly, and finally into d)the application characteristics of it for dementia care facilities. Results: The application characteristics of the therapeutic light and color for dementia care facilities are classified into both qualitative and quantitative characteristics. Qualitative application characteristics of light represented using of daylight, using of lighting approximate to daylight, expansion of iluminance level, equality in iluminance Level, reduction of shadow, and as well as exclusion of blare. Quantitative application characteristics of it represented iluminance level, color temperature and color rendering index prescribed in international lighting standards. Qualitative application characteristics of color represented non-monochromatic color, color contrast, long wavelength of yellow-red colors, exclusion of short wavelength of blue colors and patterns, and as well as different colors for idenfication. Quantitative application characteristics of it represented kontrast(K) prescribed in DIN32975:2009 and light reflectance value(LRV) prescribed in BS8300:2009. Implications: To form dementia care facilities as therapeutic environment both qualitative and quantitative application characteristics of therapeutic light and color in dementia care facilities are needed.

The use of ZrO2 as an electron-injecting layer in hybrid metal-oxide/polymer light-emitting diodes

  • Tokmoldin, Nurlan;Bradley, Donal D.C.;Haque, Saif
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.779-780
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    • 2009
  • New inverted architecture of a hybrid inorganic-organic light-emitting diode, utilizing ZrO2 electron-injecting layer, is presented. The thickness of the ZrO2, as well as the annealing of the light-emitting polymer, is found critical to obtain good performance. A range of light-emitting polymers is shown to operate efficiently in the proposed architecture.

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양자우물 두께와 인듐조성 변화에 의한 470 mm RC-LED InGaN/GaN 양자우물 구조의 최적화 (Optimization of the InGaN/GaN quantum well structure for 470 mm RC-LED with variation of quantum well thickness and Indium composition)

  • 임재문;박창영;박광욱;이용탁
    • 한국광학회:학술대회논문집
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    • 한국광학회 2009년도 동계학술발표회 논문집
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    • pp.509-510
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    • 2009
  • The optical gain of InGaN/GaN multi quantum well (MQW) resonant-cavity light-emitting diode (RC-LED) with different Indium composition and well width in the multi-quantum well was investigated. The optimized optical gain was obtained by simulating active region InGaN/GaN with some test values of well width and Indium composition. By simulation tool, we could simulate on several cases, and then we got exact well width and Indium composition that makes optical gain maximum due to the short wavelength of 470 nm for blue light emission.

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Simulation of the light emission from quantum-well based heterojunction bipolar transistors

  • 박영규;박문호;김광웅;박정호
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2009년도 추계학술대회 논문집
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    • pp.52-52
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    • 2009
  • In this work, we demonstrate the modelling and simulation of the AlGaAs/GaAs quantum-well based light emitting transistor(LET). Based on the experimental and theoretical model, we have compared between a heterojunction bipolar transistor(HBT) structure with quantum wells in the base region and a HBT without quantum wells in the base region. For the purpose of optimizing device design, several analytic and numerical studies have been presented.

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시금치에서 분이한 엽록체의 인산대사에 관한 연구 (A Study on Phosphate Metabolism of Chloroplast Isolated from Spinach)

  • 이종삼
    • Journal of Plant Biology
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    • 제19권3호
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    • pp.71-84
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    • 1976
  • In order to observe the phosphate metabolism in chloroplast, the contents of inorganic phosphate and various compounds in chloroplast from spinach leaf tissues were investigated during the reaction in the light and dark in the reaction mixture and the turnover of phosphate in chloroplast was compared with that of whole cell system: 1. The phosphorus of DNA in chloroplast appears to be transferred from inorganic phosphate, while in whole cell system from phosphate pool. 2. $^{32}P-phosphate$ content of acid soluble fraction in chloroplast as well as in whole cell system was more increased in the light than dark during the reaction. It was noted to be caused by the stimulation of sugar phosphate synthesis in the light. 3. It was confirmed that polyphosphate exists in chloroplast as well as whole cell. Acid insoluble polyphosphate content in whole cell system was significantly decreased during the reaction and the similar tendency was also observed in chloroplst. It is, therefore, considered that acid insoluble polyphosphate also play an most important role as a phosphate pool respectively in chloroplast and in cytoplasm. 4. Protein and lipid phosphorus in chloroplast as well as whole cell system were transferred from acid insoluble polyphosphate.

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Intelligent Traffic Light using Fuzzy Neural Network

  • Park, Myeong-Bok;You-Sik, Hong
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제3권1호
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    • pp.66-71
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    • 2003
  • In the past, when there were few vehicles on the road, the T.O.D.(Time of Day) traffic signal worked very well. The T.O.D. signal operates on a preset signal cycling which cycles on the basis of the average number of average passenger cars in the memory device of an electric signal unit. Today, with increasing traffic and congested roads, the conventional traffic light creates startup-delay time and end lag time so that thirty to forty-five percent efficiency in traffic handling is lost, as well as adding to fuel costs. To solve this problem, this paper proposes a new concept of optimal green time algorithm, which reduces average vehicle waiting time while improving average vehicle speed using fuzzy rules and neural networks. Through computer simulation, this method has been proven to be much more efficient than fixed time interval signals. Fuzzy Neural Network will consistanly improve average waiting time, vehicle speed, and fuel consumption.