• 한국안광학회지
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• 제14권2호
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• pp.27-30
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• 2009

목적: 현재 판매되어지고 있는 SCL의 건조 및 젖음 상태에 따라 UV 및 가시광선 투과율을 측정하였다. 방법: 시중에 유통 중인 5가지 종류의 재료를 건조 및 젖음 상태에 따라 Spectrophotometer로 측정하여, SCL의 광학적 특성을 조사하였다. 결과: 5가지 재료 중에서 젖음 및 건조 상태의 구별없이 일정한 투과값을 가진 재료도 있었다. 측정된 SCL의 가시광선 범위 투과율은 약 80% 이상의 투과율이 나와 광학적으로 우수하였다. 또한 대다수 SCL의 경우 UV에서 젖음 상태의 투과율이 건조 상태보다 높은 투과율을 나타냈다. 결론: 측정된 SCL의 재료 중에는 가시광선 범위에서 우수한 광학적 성능을 보였지만 대다수 SCL의 경우 UV 범위에서 높은 투과율이 나타냈다. 그러므로 앞으로 UV를 차단 기능이 있는 신소재 개발의 필요성이 강조될 것이다.

• Journal of Biosystems Engineering
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• 제33권1호
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• pp.63-68
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• 2008

This study was carried out to find a useful method to predict hardness of tomato using optical spectrum data. Optical spectrum of reflectance and transmittance data were collected processed by 9 kind of preprocessing methods-normalizations of mean, maximum and range, SNV (standard normal variate), MSC (multiplicative scatter correction), the first derivative and second derivative of Savitzky-Golay and Norris-Gap. With the preprocessed and non-processed original spectrum data, prediction models of hardness of tomato were developed using analytical tools of PLS (partial least squares) and MLR (multiple linear regression) and tested for their validation. The test of validation resulted that the analytical tools of PLS and MLR output similar performances while the transmittance spectra showed much better result than the reflectance spectra.

• 한국작물학회지
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• 제51권5호
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• pp.451-457
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• 2006

분쇄하지 않은 정조상태에서 현미와 백미의 성분을 측정 할 목적으로 수확 후 정조로부터 스펙트럼을 획득하였고(투과법 : 850-1050 nm, 반사법 : 400-2500 nm) 현미와 백미의 단백질, 아밀로스, 지방산, 수분함량, 식미값의 예측모델을 개발하여 그 정밀도를 비교 검토하기 위해서 일련의 시험을 실시한 결과는 다음과 같다. 투과법으로 정조의 스펙트럼을 수집한 후 현미의 단백질, 아밀로스, 지방산, 수분함량의 검량식을 작성한 결과 0.9001, 0.8321, 0.8077, 0.9553의 결정계수를 나타냈다. 백미의 단백질, 아밀로스, 수분함량, 식미값의 검량식을 작성한 결과 0.8255, 0.8559, 0.8226, 0.3421의 결정계수를 나타냈다. 반사법으로 정조의 스펙트럼을 수집한 후 현미의 단백질, 아밀로스, 지방산, 수분함량의 검량식을 작성한 결과 0.8286, 0.7705, 0.9094, 0.9694의 결정계수를 나타냈다. 백미의 단백질, 아밀로스, 수분함량, 식미값의 검량식을 작성한 결과 0.7904, 0.7679, 0.8435, 0.4881의 결정계수를 나타냈다. 이상의 결과에 의해서 단백질, 아밀로스, 지방산, 수분함량은 실용적인 결정계수를 얻었으나, 식미값은 결정계수가 너무 낮아 계속적인 연구가 필요하다고 판단하였다.

• 한국진공학회지
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• 제17권2호
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• pp.138-147
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• 2008

RF 스퍼터링 시스템을 이용하여 $SiO_2/TiO_2/ZrO_2$ 광대역 반사방지막을 단계별로 제작하였고, 분광타원계와 $UV-V_{is}$ 분광광도계를 이용하여 박막의 두께, 굴절률 및 투과율 스펙트럼을 300$\sim$900nm의 파장 영역에 걸쳐 측정 및 분석하였다. 측정 및 분석된 박막의 두께, 굴절률 및 투과율 스펙트럼을 설계값과 비교 평가한 결과 각층의 두께, 굴절률의 차이에 따른 투과율의 변화를 분석할 수 있었고, 박막의 두께보다는 굴절률과 굴절률의 분산형태가 투과율의 변화에 더 크게 기여함을 알 수 있었다.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1529-1529
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• 2001

The watercore in apple is very important factor in storage and sorting of fruit. Most consumers tend to prefer the apple included watercore in immediately after harvest, however the watercore causes fruit flesh to brown during storage and lose the worth after all. But it is practically impossible to judge to the naked eye whether an apple has watercore or not. Therefore, the rapid, accurate and non-destructive analysis method for discrimination of watercore should be settled without delay. In this study we attempted the discrimination and quantitative analysis of watercore in apple fruit using near-infrared transmittance spectroscopy ‘Fuji’ apple fruits produced in Kyungpook of Korea was used in this experiment. The watercore content in apple was evaluated by graphic treatment of culled slice sections(10 mm). NIR transmittance spectra were collected over the 500 to 1000 nm spectral region with a spectrometer (Sentronic Co., Germany). The calibration models were carried out by partial least squares (PLS) analysis between NIR spectra data of apples and chemical data of watercore content. The spectra were different in absorbance between apple included watercore and not included one. Apple included watercore had higher absorption band than sample not included one at 732 and 820 nm. The calibration model seems to be accurate to predict the watercore content in apple fruit, the correlation coefficient (R) and root mean square error of prediction (RMSEP) were 0.99 and 0.93%, respectively. This result indicates that the PLSR calibration model by using NIR transmittance spectroscopy could be used for discrimination of watercore in apple fruit.

• 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.

• Journal of Biosystems Engineering
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• 제35권6호
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• pp.450-457
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• 2010

Although cherry tomato is one of major vegetables consumed in fresh vegetable market, the quality grading method is mostly dependant on size measurement using drum shape sorting machines. Using Visible/Near-infrared spectroscopy, apparatus to be able to acquire transmittance spectrum data was made and used to estimate firmness, sugar content, and acidity of cherry tomatoes grown at hydroponic and soil culture. Partial least square (PLS) models were performed to predict firmness, sugar content, and acidity for the acquired transmittance spectra. To enhance accuracy of the PLS models, several preprocessing methods were carried out, such as normalization, multiplicative scatter correction (MSC), standard normal variate (SNV), and derivatives, etc. The coefficient of determination ($R^2_p$) and standard error of prediction (SEP) for the prediction of firmness, sugar, and acidity of cherry tomatoes from green to red ripening stages were 0.859 and 1.899 kgf, with a preprocessing of normalization, 0.790 and $0.434^{\circ}Brix$ with a preprocessing of the 1st derivative of Savitzky Golay, and 0.518 and 0.229% with a preprocessing normalization, respectively.

• 한국광학회지
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• 제15권1호
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• pp.63-67
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• 2004

이론적으로 계산된 투과 및 반사 스펙트럼을 실험적으로 측정된 결과에 대해 곡선 맞춤(curve fitting)을 수행하여 콜레스테릭 액정 필름(CLC, cholesteric liquid crystal)의 광학 상수를 결정하였다. 이론적인 투과 및 반사 스펙트럼 계산을 위해 Bewemn의 4${\times}$4행렬법이 사용되었다. 서로 다른 반사밴드를 갖고 있는 세 종류의 샘플에 대해 이 방법을 적용하였다 CLC샘플에 대한 곡선 맞춤 결과로부터 얻은 굴절률 값을 수평 배향된 LC샘플에 대해 측정된 값과 비교하였는데, 두 결과는 세 CLC 샘플에 대한 곡선 맞춤 결과 오차 범위 내에서 일치하였다.

• 한국산업융합학회 논문집
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• 제4권1호
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• pp.35-40
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• 2001

A spectral measurement system for reflection and transmission properties by using an optical fiber and an ellipsoidal mirror was newly developed. The hemispherical reflectance and transmittance spectra of several heating resisting ceramics materials were measured from visible to middle infrared region. The directional characteristics of reflection and transmission were also investigated in consideration of the absorptance. The measured data were analyzed by using a four flux model of radiation transfer, The radiation properties could be estimated by the obtained scattering and absorption coefficient spectra.

• Journal of Biosystems Engineering
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• 제33권5호
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• pp.309-316
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• 2008

The goal of this study was to develop prediction models to estimate the storage days of tomato. The transmittance spectral data measured on tomato were preprocessed through normalization, SNV, Savitzky-Golay, and Norris Gap and then were used to build the prediction models using partial least square (PLS) method. For the experiments, the tomato samples of different varieties were collected at different harvest time. The samples were taken right after harvest from the field and then were stored in a low-temperature storage room in which room temperature was maintained at $10^{\circ}C$. The transmittance spectral data of the tomato samples were measured at three-day intervals for 16 days. The performance of the prediction models was affected by the preprocessing techniques as well as the varieties and harvest time of the tomato. The best model was found when SNV was applied. The accuracy of the best model was 90.2%. It can be concluded that the transmittance spectra are useful information for predicting the period of storage of tomato.