• 제목/요약/키워드: Transmittance spectrum

검색결과 126건 처리시간 0.03초

TiO2/SiO2 다층 박막 평판 mirror의 광학적 반사 (Optical reflectance of TiO2/SiO2 multilayer coating flat mirrors)

  • 이찬구;이수대;정맹식
    • 한국안광학회지
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    • 제7권1호
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    • pp.75-78
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    • 2002
  • 파장범위 620~820nm에서 반사가 큰 $TiO_2/SiO_2$ 33층 박박 mirror를 설계하고 전자 빔 증착 방법으로 제작하였다. 다층박막은 BK7 유리 기판에 연속적으로 증착하였다. 고반사박막 설계는 중심파장 ${\lambda}_0$ 주변에 stopband가 만들어지는 것과 같은, 고굴절률을 가지는 층($n_H$)과 저굴절률을 가지는 층($n_L$)을 반복해서 하였다. 입사각 $40^{\circ}{\pm}7^{\circ}$인 투과도 측정 스펙트럼에서 전체적으로 파장범위 620~820nm에서 99.9%의 반사를 보였다. 파장이 700~740nm에서 투과도가 큰 피크를 보였다.

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Applications of Discrete Wavelet Analysis for Predicting Internal Quality of Cherry Tomatoes using VIS/NIR Spectroscopy

  • Kim, Ghiseok;Kim, Dae-Yong;Kim, Geon Hee;Cho, Byoung-Kwan
    • Journal of Biosystems Engineering
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    • 제38권1호
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    • pp.48-54
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    • 2013
  • Purpose: This study evaluated the feasibility of using a discrete wavelet transform (DWT) method as a preprocessing tool for visible/near-infrared spectroscopy (VIS/NIRS) with a spectroscopic transmittance dataset for predicting the internal quality of cherry tomatoes. Methods: VIS/NIRS was used to acquire transmittance spectrum data, to which a DWT was applied to generate new variables in the wavelet domain, which replaced the original spectral signal for subsequent partial least squares (PLS) regression analysis and prediction modeling. The DWT concept and its importance are described with emphasis on the properties that make the DWT a suitable transform for analyzing spectroscopic data. Results: The $R^2$ values and root mean squared errors (RMSEs) of calibration and prediction models for the firmness, sugar content, and titratable acidity of cherry tomatoes obtained by applying the DWT to a PLS regression with a set of spectra showed more enhanced results than those of each model obtained from raw data and mean normalization preprocessing through PLS regression. Conclusions: The developed DWT-incorporated PLS models using the db5 wavelet base and selected approximation coefficients indicate their feasibility as good preprocessing tools by improving the prediction of firmness and titratable acidity for cherry tomatoes with respect to $R^2$ values and RMSEs.

벗풀(Sagittaria trifolia L.)의 번식생장(繁殖生長) 및 경합생태(競合生態) - 1. 벗풀의 번식생장(繁殖生長) (Reproductive Growth and Competitive Ecology of Arrowhead(Sagittaria trifolia L.) - 1. Growth and Tuber Formation of Arrowhead under Several Environmental Factors)

  • 한성수
    • 한국잡초학회지
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    • 제13권2호
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    • pp.138-150
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    • 1993
  • 본(本) 실험(實驗)은 환경요인(環境要因)의 변동(變動)에 따른 벗풀의 생장(生長) 및 지하경번식체(地下莖繁殖體) 생산량(生産量)을 조사(調査)하여 벗풀의 합리적(合理的)인 방제법(防除法)을 확립(確立)하는데 기초자료(基礎資料)로 활용(活用)하고자 하였는 바 다음과 같은 결과(結果)를 얻었다. 1. 광량(光量)의 차이(差異)에 따른 벗풀의 엽수(棄數)와 화경수(花莖數)는 차광정도(遮光程度)가 클수록 감소(滅少)하였고 엽폭(葉幅)은 증가(增加)하였으며 초장(草長)은 노지(露地)에서 가장 짧았다. 벗풀의 지상부(地上部) 건물중(乾物重), 지하경(地下莖)의 수(數) 및 생체중(生體重)은 50%이하(以下) 광량(光量)에서는 광량(光量)간 유의차(有意差)가 없었으나 30% 이하(以下) 광량(光量)에서는 현저(顯著)히 저하(低下)되었다. 2. 광질(光質)의 차이(差異)에 따른 벗풀의 초장(草長)은 노지(露地)에서 가장 짧았으나 엽수(葉數)는 가장 많았다. 엽장(葉長)은 녹색(綠色)필름처리(處理)에서 가장 짧았고 엽폭(葉幅)은 노지(露地)와 수명(透明)필름처리(處理)에서 좁았다. 지상부(地上部) 건물중(乾物重)은 수명(透明) 및 녹색(綠色)필름처리(處理)에서 많았고 기타(其他) 광량간(光量間)에는 유의차(有意差)가 없었다. 지하경(地下莖)의 수(數)와 생체중(生體重)은 녹색(綠色)필름처리(處理)에서 가장 적었고 노지(露地)와 수명(透明)필름처리(處理)에서 많았다. 3. 초장(草長)은 0-5cm 담수심(湛水深)에서보다 10-20cm 담수심(湛水深)에서 길었고, 담수심(湛水深)이 깊어질수록 엽수(棄數)는 적었다. 엽장(葉長)과 화경수(花莖數)는 담수심(湛水深) 변동(變動)에 큰 영향(影響)이 없었다. 지상부(地上部) 건물중(乾物重), 지하경(地下莖)의 수(數) 및 생체중(生體重)은 0cm 담수심(湛水深)에서 가장 많았고 20cm 담수심(湛水深)에서 가장 적었다. 4. 벗풀의 초장(草長), 엽수(棄數)및 엽장(葉長)은 시비량(施把量)이 많을수록 증가(增加)하는 경향(傾向)이었으나 화경수(花莖數)는 시비량(施把量)에 영향(影響)이 적엇다. 벗풀의 지상부(地上部) 건물중(乾物重) 및 지하부(地下部) 번식체(緊植體) 생산량(生産量)은 시비량(施把量)의 증가(增加)에 따라 증가(增加)하였다. 5. 벗풀 지하경(地下莖)의 중량(重量)의 차이(差異)는 생육(生育)에 영향(影響)이 적었고, 지상부(地上部) 건물중(乾物重)에도 큰 영향(影響)이 없었으나 지하부(地下部) 번식(緊植) 생산량(生産量)은 재식(栽植)한 지하경(地下莖)의 중량(重量)이 클수록 증가(增加)하였다. 6. 출수기(出穗期)의 온도조건(溫度條件)에 따른 벗풀의 생육량(生育量)은 $35^{\circ}C$에서 보다$25^{\circ}C$에서 다소(多少) 적었고 생성(生成)된 지하경(地下莖)의 수(數)와 생체중(生體重)도 적었다.

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PREDICTION OF PHYSICO-CHEMICAL AND TEXTURE CHARACTERISTICS OF BEEF BY NEAR INFRARED TRANSMITTANCE SPECTROSCOPY

  • Olivan, Mamen;Delaroza, Begona;Mocha, Mercedes;Martinez, Maria Jesus
    • 한국근적외분광분석학회:학술대회논문집
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    • 한국근적외분광분석학회 2001년도 NIR-2001
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    • pp.1256-1256
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    • 2001
  • The physico-chemical and texture characteristics of meat determine the nutritional, technological and sensory quality. However, the analysis of meat quality requires expensive, laborious and time consuming analytical methods. The objective of this study was to evaluate NIR spectroscopy using transmittance for determining the moisture, fat, protein and total pigment content, the water holding capacity (WHC) and the toughness of beef meat. A total of 318 spectra were recorded from ground beef samples by a Feed Analyzer 1265 of Infratec. The samples were obtained from the Longissimus muscle of the 10$^{th}$ rib of yearling bulls, ground with an electrical chopper, vacuum packaged, aged during 7 days and frozen at -24$^{\circ}C$ until the analyses were done. Moisture content was measured by oven drying at 10$0^{\circ}C$, fat content was determined by Soxhlet extraction and protein content was estimated from nitrogen content using the Kjeldahl analysis. The total pigment content was determined by the method of Hornsey and the WHC using the method of filter paper press. The instrumental evaluation of texture (maximum load WB, maximum stress MS and toughness) was conducted in an Instron equipment with a Warner-Bratzler shearing device. This analysis was performed on a chop of 3.5 cm obtained from the longissimus of the 8$^{th}$ rib, aged during 7 days, kept frozen at -24$^{\circ}C$ and cooked before the analysis. Near infrared spectra were recorded as log 1/T (T=transmittance) at 2 nm intervals from 850 to 1050 nm using a Feed Analyzer 1265 of Infratec. Calibrations were performed with the WinISI software (vs. 1.02) using the MPLS method. To examine the effect of scatter correction o. derivation of spectra on the calibration performance, calibrations were calculated with the crude spectra or pretreated with different mathematical treatments (inverse MSC, SNVD) and/or second derivative operation. For chemical composition, the use of the scatter corrections improved the calibration statistics, in terms of lower SECV and higher $r^2$. In most of the variables, the use of the 2$^{nd}$ derivative improved the predictions, mainly when combined with the SNVD treatment. However, for predicting the texture traits, the best estimation was obtained from the crude spectrum. These results showed that the equations obtained for predicting moisture, fat and total pigments were very accurate, with $r^2$ being higher that 0.9. However, the prediction of the texture traits (WB, MS, toughness) from ground meat was poor.

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마그네트론 스퍼터링법을 이용한 Indium-Tin Oxide 박막의 제작과 그 특성에 관한 연구 (A Study on the Fabrication and Characteristics of ITO Thin Film Deposited by Magnetron Sputtering Method)

  • 조길호;김여중;김성종;문경만;이명훈
    • Journal of Advanced Marine Engineering and Technology
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    • 제24권6호
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    • pp.61-69
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    • 2000
  • Indium-Tin Oxide (ITO) films were prepared on the commercial glass substrate by the Magnetron Sputtering method. The target was a 90wt.% $In_2O_3$-10wt.% $SnO_2$with 99.99% purity. The ITO films deposited by changing the partial pressure of oxygen gas ($O_2$/(Ar+$O_2$)) of 2, 3 and 5% as well as by changing the substrate temperature of $300^{\circ}C$ or $500^{\circ}C$. The influence of substrate pre-annealing and pre-cleaning on the quality of ITO film were examined, in which the substrate temperature was $500^{\circ}C$ and oxygen partial pressure was 3%. The characteristics of films were examined by the 4-point probe, Hall effect measurement system, SEM, AFM, Spectrophotometer, and X-ray diffraction. The optimum ITO films have been obtained when the substrate temperature is $500^{\circ}C$ and oxygen partial pressure is 3%. At optimum condition, the film showed transmittance of 81%, sheet resistivity of $226\Omegatextrm{cm}^2$, resistivity($\rho$) of $5.4\times10^{-3}\Omega$cm, carrier concentration of $1.0\times10^{19}cm^{-3}$, and carrier mobility of $150textrm{cm}^2$Vsec. From XRD spectrum, c(222) plane was dominant in the case of substrate temperature at $300^{\circ}C$, without regarding to oxygen partial pressure. However, in the case of substrate temperature at $500^{\circ}C$, c(400) plane was grown together with c(222) plane, only for oxygen partial pressure of 2 and 3%. In both case of chemical and ultrasonic cleaning without pre-annealing the substrate, it showed much almost same sheet resistivity, resistivity($\rho$), transmittance, carrier concentration, and carrier mobility. In case of $500^{\circ}C$/60min pre-annealing before ITO film deposited, both transimittance and carrier mobility are better than no pre-annealing, because pre-annealing is supposed to remove alkari ions diffusion from substrate. ITO film deposited on the Corning 0080 sybstrate showed a little bit better sheet resistivity, resistivity($\rho$), transimittance, carrier concentration than the film deposited on commercial glass. But no differences between Corning substrate and pre-annealed commercial glass substrate are found.

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THE NONDESTRUCTIVE MEASUREMENT OF THE SOLUBLE SOLID AND ACID CONTENTS OF INTACT PEACH USING VIS/NIR TRANSMITTANCE SPECTRA

  • Hwang, I.G.;Noh, S.H.;Lee, H.Y.;Yang, S.B.
    • 한국농업기계학회:학술대회논문집
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    • 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.II
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    • pp.210-218
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    • 2000
  • Since the SSC(soluble solid contents) and titratable acidity of fruit are highly concerned to the taste, the need for measuring them by non-destructive technology such as NIR(Visual and Near-infrared) spectroscopy is increasing. Specially, in order to grade the quality of each fruit with a sorter at sorting and packing facilities, technologies for online measurement satisfying the tolerance in terms of accuracy and speed should be developed. Many researches have been done to develop devices to measure the internal qualities of fruit such as SSC, titratable acidity, firmness, etc. with the VIS(Visual)/NIR(Near Infrared) reflectance spectra. The distributions of the SSC, titratable acidity, firmness, etc. are different with respect to the position and depth of fruit, and generally the VIS/NIR light can interact with fruit in a few millimeters of pathlength, and it is very difficult to measure the qualities of inner flesh of fruit. Therefore, to measure the average concentrations of each quality factor such as SSC and titratable acidity with the reflectance-type NIR devices, the spectra of fruit at several positions should be measured. Recently, the interest about the transmittance-type VIS/NIR devices is increasing. NIR light can penetrate through the fruit about 1/10-1/1,000,000 %. Therefore, very intensive light source and very sensitive sensor should be adopted to measure the transmitted light spectra of intact fruit. The ultimate purpose of this study was to develop a device to measure the transmitted light spectra of intact fruit such as apple, pear, peach, etc. With the transmittance-type VIS/NIR device, the feasibility of measurement of the SSC and titratable acidity in intact fruit cultivated in Korea was tested. The results are summarized as follows; A simple measurement device which can measure the transmitted light spectra of intact fruit was constructed with sample holder, two 500W-tungsten halogen lamps, a real-time spectrometer having a very sensitive CCD array sensor and optical fiber probe. With the device, it was possible to measure the transmitted light spectra of intact fruit such as apple, pear and peach. Main factors affecting the intensity of transmitted light spectra were the size of sample, the radiation intensity of light source and the integration time of the detector. Sample holder should be designed so that direct light leakage to the probe could be protected. Preprocessing method to the raw spectrum data significantly influenced the performance of the nondestructive measurement of SSC and titratable acidity of intact fruit. Representative results of PLS models in predicting the SSC of peach were SEP of 0.558 Brix% and R2 of 0.819, and those in predicting titratable acidity were SEP of 0.056% and R2 of 0.655.

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나린진(naringin)이 함유된 소프트 콘택트렌즈에서 나린진의 용출 특성 (Elution Properties of Naringin from Soft Contact Lens Containing Naringin)

  • 유근창;전진;진문석;채수철;김인숙
    • 한국안광학회지
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    • 제13권3호
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    • pp.45-50
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    • 2008
  • 목적: 본 연구는 천연항균물질인 나린진을 소프트 콘택트렌즈 수지용액에 첨가하여 소프트 콘택트렌즈를 제조하고, 제조된 콘택트렌즈에서 용출된 용액의 광학적 특성과 나린진의 물리화학적인 상태 그리고 식염수에서의 용출 특성 등에 대해 살펴보고자 하였다. 방법: 나린진이 첨가된 콘택트렌즈는 벌크(bulk)중합 방식을 이용하여 제조하였고, 제조된 나린진이 첨가된 콘택트렌즈에서 나린진의 결합상태와 식염수로의 나린진 용출과정, 그리고 시간에 따른 나린진의 용출량 등은 적외선 스펙트럼(IR spectrum)과 고성능 액체 크로마토그래피(HPLC)를 이용하여 살펴보았다. 결과: 나린진이 첨가된 콘택트렌즈에서 나린진의 용출은 일정농도를 유지하면서 약 1개월 동안 지속되었고, 용출된 나린진은 첨가하기 전과 동일한 구조를 유지하고 있었으며 투과율과 같은 광학적 특성 변화는 관찰할 수 없었다. IR spectrum과 HPLC 결과로부터 콘택트렌즈 내에서 나린진의 구조와 결합상태를 확인하였다. 결론: 나린진이 첨가된 콘택트렌즈에서 나린진은 폴리머 분자와 반데르발스(van der Waals) 인력이나 나린진 분자의 수산기 (hydroxyl group)와 약한 수소결합(hydrogen bonding)에 의해 상호 결합되어 있는 것으로 판단되었다. 나린진이 첨가된 콘택트렌즈로부터 나린진은 약 1개월 동안 일정농도씩 꾸준히 용출되었으며 1개월 후에도 하루 동안 용출된 나린진의 농도가 약 10 ppm으로 나타나 일정기간 동안 항균력의 유지가 지속적으로 필요한 소프트 콘택트렌즈의 제조에 나린진을 첨가하는 방법이 매우 효과적임을 알 수 있었다.

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지상 원격탐사의 농업적 활용 (Agricultural Application of Ground Remote Sensing)

  • 홍순달;김재정
    • 한국토양비료학회지
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    • 제36권2호
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    • pp.92-103
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    • 2003
  • Research and technological advances in the field of remote sensing have greatly enhanced the ability to detect and quantify physical and biological stresses that affect the productivity of agricultural crops. Reflectance in specific visible and near-infrared regions of the electromagnetic spectrum have proved useful in detection of nutrient deficiencies. Especially crop canopy sensors as a ground remote sensing measure the amount of light reflected from nearby surfaces such as leaf tissue or soil and is in contrast to aircraft or satellite platforms that generate photographs or various types of digital images. Multi-spectral vegetation indices derived from crop canopy reflectance in relatively wide wave band can be used to monitor the growth response of plants in relation to environmental factors. The normalized difference vegetation index (NDVI), where NDVI = (NIR-Red)/(NIR+Red), was originally proposed as a means of estimating green biomass. The basis of this relationship is the strong absorption (low reflectance) of red light by chlorophyll and low absorption (high reflectance and transmittance) in the near infrared (NIR) by green leaves. Thereafter many researchers have proposed the other indices for assessing crop vegetation due to confounding soil background effects in the measurement. The green normalized difference vegetation index (GNDVI), where the green band is substituted for the red band in the NDVI equation, was proved to be more useful for assessing canopy variation in green crop biomass related to nitrogen fertility in soils. Consequently ground remote sensing as a non destructive real-time assessment of nitrogen status in plant was thought to be useful tool for site specific crop nitrogen management providing both spatial and temporal information.

광흡수단을 제어를 이용한 UV 차단렌즈 개발 (UV-cut Lens Manufacture using Optical Absorption Edge Control)

  • 김용근;박동화;성정섭
    • 한국안광학회지
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    • 제7권1호
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    • pp.29-34
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    • 2002
  • Venzotriazol계를 증류수로 희석(5%)하여 만든 UV 차단 출발액을 dip 방법으로 각각 1, 2, 5, 15, 20, 30분 간격으로 유지시켜 UV 차단렌즈의 시료를 제작하였다. 각 시료에 대한 광 투과율의 spectrum은 320~450nm 영역에서 측정하였다. 그 결과 광흡수 edge는 각각 403, 408, 414, 419nm 영역이며, 각각 3.07, 3.04, 2.99, 2.96eV의 band에서 흡수 edge가 나타났다. UV 차단 렌즈 출발용액은 benzophenone계의 2-Hydroxy-4-n-octoxybenzo-phenone를 methanol에 녹여 5%, 10%을 만들고, UV 차단 렌즈는 Spray pyrolysis method로 만들었다. 등 간격으로 분무한 각 렌즈의 투과 광의 edge는 spectra에서 거의 등 간격을 보였다. 2, 4, 6분 동안 분무할 때의 광 흡수 edge는 385, 398, 417nm 영역이며, band는 각각 3.22, 3.11, 2.97eV를 이루고 있다.

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InSe 단결정의 전기적 광학적 특성에 관한 연구 (Electrical and Optical Properties of InSe Single Crystals)

  • 김창대;이철기;조동산
    • 대한전자공학회논문지
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    • 제19권5호
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    • pp.1-4
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    • 1982
  • Bridgman방법으로 Inse 단결정을 성장시켰다. 성장된 단결정은 rhombohedral 구조를 가지고 있으며 격자 상수는 a=4.02A, c=24.96A이고 전기 전도도는 300°K에서 ∼10-1, 50°K에서 ∼10-6(Ω·cm)-1이다. 전기 전도형은 n형으로 도우너 (donor) 준위는 전도대밑 0.072ev 되는 점에 위치하고 있다. 광전도도는 840nm부터 1120nm까지의 영역에서 감도를 가지고 있으며 광투과 특성으로부터 구한 InSe의 에너지 갭(gap)은 1.21ev이다.

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