• 제목/요약/키워드: Visible spectrum analysis

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오디오 스펙트럼을 이용한 LED 감성 조명 알고리즘과 응용 (LED Emotional Lighting Algorithm and Application using Audio Spectrum)

  • 장영범;석상철
    • 한국통신학회논문지
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    • 제36권10B호
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    • pp.1252-1257
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    • 2011
  • 이 논문에서는 오디오 신호의 스펙트럼 가시광선 스펙트럼으로 매핑하는 감성 조명 방식을 제안한다. 인간의 청각이 인지하는 오디오 스펙트럼의 전 대역을 시각이 인지하는 가시광 스펙트럼의 전 대역으로 매핑하는 조명 알고리즘을 제안하며 특히 기본적인 선행 매핑 방식과 특정 주파수 대역을 가조하는 비선형 스펙트럼 매핑 방식에 대하여 논한다. 알고리즘의 효과를 실험하기 위하여 DSP 보드로 구현함으로써 제안된 조명 방식의 응용 가능성을 보였다. 따라서 제안된 조명 방식은 스탠드 LED 조명, 화병 LED 조명, 분수용 LED 조명, 건축물용 LED 조명, 노래방용 LED 조명, 청각 장애인용 LED 음악조명 등의 분야에 응용될 수 있을 것이다.

STANDARIZING THE EXTRATERRESTRIAL SOLAR IRRADIANCE SPECTRUM FOR CAL/VAL OF GEOSTATIONARY OCEAN COLOR IMAGER (GOCI)

  • Shanmugam, Palanisamy;Ahn, Yu-Hwan
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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    • pp.86-89
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    • 2006
  • Ocean color remote sensing community currently uses the different solar irradiance spectra covering the visible and near-infrared in the calibration/validation and deriving products of ocean color instruments. These spectra derived from single and / or multiple measurements sets or models have significant discrepancies, primarily due to variation of the solar activity and uncertainties in the measurements from various instruments and their different calibration standards. Thus, it is prudent to examine model-to-model differences and select a standard reference spectrum that can be adopted in the future calibration and validation processes, particularly of the first Geostationary Ocean Color Imager (GOCI) onboard its Communication Ocean and Meterological Satellite (COMS) planned to be launched in 2008. From an exhaustive survey that reveals a variety of solar spectra in the literature, only eight spectra are considered here seeing as reference in many remote sensing applications. Several criteria are designed to define the reference spectrum: i.e., minimum spectral range of 350-1200nm, based completely or mostly on direct measurements, possible update of data and less errors. A careful analysis of these spectra reveals that the Thuillier 2004 spectrum seems to be very identical compared to other spectra, primarily because it represents very high spectral resolution and the current state of the art in solar irradiance spectra of exceptionally low uncertainty ${\sim}0.1%.$ This study also suggests use of the Gueymard 2004 spectrum as an alternative for applications of multispectral/multipurpose satellite sensors covering the terrestrial regions of interest, where it provides spectral converge beyond 2400nm of the Thuillier 2004 spectrum. Since the solar-activity induced spectral variation is about less than 0.1% and a large portion of this variability occurs particularly in the ultraviolet portion of the electromagnetic spectrum that is the region of less interest for the ocean color community, we disregard considering this variability in the analysis of solar irradiance spectra, although determine the solar constant 1366.1 $Wm^{-2}$ to be proposed for an improved approximation of the extraterrestrial solar spectrum in the visible and NIR region.

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펄스형 방전플라스마에서 발생하는 가시광선의 분광특성 연구 (Spectroscopy of Visible Light Emitted from Plasma Occurred by Pulse Discharge)

  • 최운상
    • 한국안광학회지
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    • 제3권1호
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    • pp.27-31
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    • 1998
  • 펄스형 방전플라즈마 발생장치인 플라스마 포커스장치에서 발생하는 가시광선영역의 빛을 시간분해분석법과 시간적분분석법으로 분광분석하였다. 플라스마포커스장치는 전극이 동축형으로 사용되었고, 시간 용해분석법은 고정된 파장의 광펄스를 오실로스코프로 분석하였으며, 시간 적분법을 일정한 범위의 파장대를 필림에 현상하여 densitometer로 분석하였다. 가시광선발생은 방전전압과 기체압력을 변수로 측정하여 방전전압은 17 kV이고 기체압력은 아르곤기체일 경우 0.5 torr가 최적조건이었다.

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In-Ceram Alumina Core와 IPS Empress 2 core의 분광반사율 연구 (A study on reflective spectrum between In-Ceram alumina core and IPS Empress 2 core)

  • 박명자;김주원
    • 대한치과기공학회지
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    • 제23권2호
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    • pp.189-202
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    • 2002
  • A study on reflective spectrum between In-Ceram alumina plate(IAP) and IPS empress 2 plate were carried out in order to determine the difference of reflective spectrum rates between materials and between thicknesses of materials(0.8mm, 1.0mm, 1.2mm) by visible wave. The rates are measured by spectrophotometer(Top scan model TC-1800). And an analysis of ANOVA and paired sample t-test were carried out. The results are summarized as follows. 1. The reflective rates of IAP and IPS increased slowly as visible wave spectrum increased. 2. The difference of reflective rates of IAP between 0.8mm and 1.0mm is significant but a little(less than 1%). The differences of reflective rates of IAP between 0.8mm and l.2mm and between 1.0mm and l.2mm are significant(8%, 10% ). 3. The differences of reflective rates of IPS between 0.8mm and 1.0mm and between 0.8mm and 1.2mm and between 1.0mm and 1.2mm are significant(0.06 %, 0.01 %, 2 %). 4. The differences of reflective rates of 0.8mm, 1.0mm between IAP and IPS are significant but a little(less than 0.9%, 0.5%). The difference of reflective rates of l.2mm between IAP and IPS is significant and larger than the other thicknesses relatively(7 %).

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가시광을 이용한 육질의 비파괴적 측정에 관한 연구 (A study on the nondestructive measurement of meat quality using visible light)

  • 맹갑주;이영우
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2009년도 춘계학술대회
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    • pp.248-250
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    • 2009
  • 육질의 특성을 파악하기 위해 광학적인 방식의 비파괴적인 측정 방법을 사용하여 실험을 수행하였다. 육질의 특성은 분광 분석법을 사용하여 측정하였다. 이를 통해 육질의 근육 및 지방의 분포에 따른 특성의 파악이 가능할 것으로 예상된다.

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연수정 육성에 관한 연구 (A Study on Growth of Smoky Quartz)

  • 박로학;유영문
    • 한국결정학회지
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    • 제1권2호
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    • pp.61-65
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    • 1990
  • 수열육성법 (Hydrothermal growth technique)으로 연수정을 육성하고 원료, 용제, 발색제, 종자결정 및 irradiation등의 요소가 육성된 결정에 미치는 영향에 대하여 고찰하였다. UV-visible spectrum분석에 의해 육성된 결정과 천연 연수정의 광학적 특성 을 비교하였다. 본 연구결과로 결함이 적고 연색 (연색)이 선명한 길이 120mm. 폭 35mm, 두께 14m (135g)의 연수정 육성에 성공하였다.

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N-docosylquinolium-(TCNQ) 단분자막의 ${\prod}-A$ 및 UV 특성 (${\prod}-A$ and UV-visible characteristics of N-docosylquinolium-(TCNQ) monolayer)

  • 박승규;최강훈;최용성;권영수;홍언식;강도열
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1991년도 추계학술대회 논문집 학회본부
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    • pp.333-335
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    • 1991
  • ${\prod}-A$ characteristics and UV-visible spectrum of N-docosylquinolium-TCNQ monolayers were investigated. ${\prod}-A$ characteristics of N-docosylquinolium-TCNQ monolayer were measured following variation. i > ${\prod}-A$ characteristics with a variation of spreading amount. ii > ${\prod}-A$ characteristics with a variation of subphase temperature. An optium surface pressure for a LB Film deposition was found to be a 30, 45 mN/m in pure water subphase(pH 5.4, $25^{\circ}C$). UV-visible spectrum Analysis of these LB film were investigated. As a result, we think two kinds of surface pressure had no effect the monolayer aggregation but monolayer density.

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Photokinesis of Cyanobacterium Synechocystis sp. PCC 6803

  • Chung, Young-Ho;Park, Young-Mok;Moon, Yoon-Jung;Lee, Eun-Mi;Choi, Jong-Soon
    • Journal of Photoscience
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    • 제11권3호
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    • pp.89-94
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    • 2004
  • Motile cyanobacterium Synechocystis sp. PCC 6803 cells show photomovement with respect to the light stimulus. Under lateral irradiation, Synechocystis displays a phototactic gliding movement toward the light source by a twodimensional random biased walk. Under vertical irradiation, Synechocystis decreased the frequency of mean vectorial gliding speed dependent on the applied fluence rate, whereas the deviation distribution width of the speed increased. This strongly suggests the involvement of photokinesis. Evidence for the cyanobacterial photokinesis was discussed in the previous report (Choi et al., 1999. Photochem. Photobiol. 70, 95-102) demonstrating that the gross scalar speed of vertically irradiating cells increased by about 50% compared with that of dark-adapted cells. In the visible wavelength range, Synechocystis cells showed a maximal photokinetic activity at 420 nm and a second maximal activity at 680 nm. The threshold action spectrum for the photokinesis resembles the absorption spectrum of chlorophyll with major differences in the phototaxis action spectrum at 560 nm and 660 nm. We postulate that the cyanobacterial photokinesis is powered by the energy-generating chlorophyll pigments.

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Spectroscopic Identification of Isomeric Trimethylbenzyl Radicals Generated from 1,2,3,4-Tetramethylbenzene

  • Yoon, Young-Wook;Lee, Sang-Kuk
    • Bulletin of the Korean Chemical Society
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    • 제32권8호
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    • pp.2751-2755
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    • 2011
  • The visible vibronic emission spectrum was recorded from the corona discharge of precursor 1,2,3,4-tetramethylbenzene with a large amount of inert carrier gas helium using a pinhole-type glass nozzle coupled with corona excited supersonic expansion. The spectrum showed a series of vibronic bands in the $D_1{\rightarrow}D_0$ electronic transition of jet-cooled benzyl-type radicals formed from the precursor in a corona excitation. The analysis confirmed that two isomeric radicals, 2,3,4- and 2,3,6-trimethylbenzyl radicals, were produced as a result of removal of a hydrogen atom from the methyl group at different substitution positions. For each isomeric product, the electronic transition and a few vibrational mode frequencies were determined in the ground electronic state.