• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.4112-4112
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• 2001

The feasibility of NIR spectroscopy as a quick and nondestructive method for quality control of uniformity of coating thickness of pharmaceutical tablets was investigated. Near infrared spectra of a set of pharmaceutical tablets with varying coating thickness were measured with a diffuse reflectance fiber optic probe connected to a Broker IFS 28/N FT-NIR spectrometer. The challenging issues encountered in this study included: 1. The similarity of the formulation of the core and coating materials, 2. The lack of sufficient calibration samples and 3. The non-linear relationship between the NIR spectral intensity and coating: thickness. A peak at 7184 $cm^{-1}$ was identified that differed for the coating material and the core material when M spectra were collected at 2 $cm^{-1}$ resolution (0.4 nm at 7184 $cm^{-1}$). The study showed that the coating thickness can be analyzed by polynomial fitting of the peak area of the selected peak, while least squares calibration of the same data failed due to the lack of availability of sufficient calibration samples. Samples of coal powder and solid pieces of coal were analyzed by FT-NIR diffuse reflectance spectroscopy with the goal of predicting their ash content, percentage of volatile components, and energy content. The measurements were performed on a Broker Vector 22N spectrometer with a fiber optic probe. A partial least squares model was constructed for each of the parameters of interest for solid and powdered sample forms separately. Calibration models varied in size from 4 to 10 PLS ranks. Correlation coefficients for these models ranged from 86.6 to 95.0%, with root-mean-square errors of cross validation comparable to the corresponding reference measurement methods. The use of FT-NIR diffuse reflectance measurement techniques was found to be a significant improvement over existing measurement methodologies in terms of speed and ease of use, while maintaining the desired accuracy for all parameters and sample forms.(Figure Omitted).

• 농업과학연구
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• 제43권5호
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• pp.715-722
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• 2016

Rapid determination of food quality is important in food distribution. In this study, the chemical properties of oats were analyzed using visible-near infrared (VIS-NIR) spectroscopy. The objective of this study was to develop and validate a predictive model of oat quality by VIS-NIR spectroscopy. A total of 200 oat samples were collected from domestic and import markets. Reflectance spectra, moisture, protein, fat, Fe, and K of oat samples were measured. Reflectance spectra were measured in the wavelength range of 400 - 2,500 nm at 2 nm intervals. The reflectance spectrum of an oat sample was measured after sample cell and reflectance plate spectrum measurement. Preprocessing methods such as normalization and $1^{st}$ and $2^{nd}$ derivations were used to minimize the spectroscopic noise. The partial-least-square (PLS) models were developed to predict chemical properties of oats using a commercial software package, Unscrambler. The PLS models showed the possibility to predict moisture, protein, and fat content of oat samples. The coefficient of determination ($R^2$) of moisture, protein, and fat was greater than 0.89. However, it was hard to predict Fe and K concentrations due to their low concentrations in the oat samples. The coefficient of determinations of Fe and K were 0.57 and 0.77, respectively. In future studies, the stability and practicability of these models should be improved by using a high accuracy spectrophotometer and by performing calibrations with a wider range of oat chemicals.

• Journal of the korean society of oceanography
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• 제38권4호
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• pp.166-172
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• 2003

Multi­Sensor Core Logger (MSCL) is a useful system for logging the physical properties (compressional wave velocity, wet bulk density, fractional porosity, magnetic susceptibility and/or natural gamma radiation) of marine sediments through scanning of whole cores in a nondestructive fashion. But MSCL has a number of problems that can lead to spurious results depending on the various factors such as core slumping, gas expansion, mechanical stretching, and the thickness variation of core liner and sediment. For the verification of MSCL data, compressional wave velocity, wet bulk density, and porosity were measured on discrete samples by Hamilton Frame and Gravimetric method, respectively. Acoustic impedance was also calculated. Physical property data (velocity, wet bulk density, and impedance) logged by MSCL were slightly larger than those of discrete sample, and porosity is reverse. Average difference between MSCL and discrete sample at both sites is relatively small such as 22­24 m/s in velocity, $0.02­-0.08\;g/\textrm{cm}^3$ in wet bulk density, and 2.5­2.7% in porosity. The values also show systematic variation with sediment depth. A variety of factors are probably responsible for the differences including instrument error, various measurement method, sediment disturbance, and accuracy of calibration. Therefore, MSCL can be effectively used to collect physical property data with high resolution and quality, if the calibration is accurately completed.

• 해양환경안전학회지
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• 제26권2호
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• pp.219-226
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• 2020

선체구조의 품질검사 중 가장 일반적인 방법의 하나는 비파괴검사이다. 하지만 복합소재 선체는 강화재와 수지로 구성된 여러가지 재료가 섞여 있고 또 생산환경과 작업자에 따라 FRP(Fiber-Reinforced Plastics) 제작품질에 차이가 발생할 가능성이 크기 때문에 정확한 검사평가는 쉽지 않은 일이다. 특히 FRP 선박의 경우에는 다른 구조물보다 두께가 매우 두껍고 주로 수척층 공법을 이용하기 때문에 더욱 그렇다. 초음파 탐상의 조건 중 검사체의 밀도가 매우 중요하기 때문에 본 연구에서는 FRP 선박 제작에 널리 사용되고 있는 소재와 유리섬유강화재 중량 비율로 제작된 선박의 외판을 검사체로 선정하고, Pulse-Echo 초음파 탐상기를 활용하여 GFRP(Glass Fiber-Reinforced Plastics) 선체 외판의 초음파 탐상을 위한 적정 조건을 조사하였다. 1.00 MHz, 2.25 MHz, 5.00 MHz 세 종류 탐촉자로 A-Scan을 실시하였으며 선체 외판의 두께 검사결과와 비교분석함으로써 적정 초음파 탐상 조건을 찾고자 하였다. 연구결과 탐촉자의 초음파 주파수가 높아질수록 수신자의 반사파 음향 속력을 감소시켜야 더 정도 높은 두께 측정 결과를 얻을 수 있었으며, 상대적으로 낮은 초음파 주파수 탐촉자에서 더 적은 오차가 발생함을 확인할 수 있었다.

• Asian-Australasian Journal of Animal Sciences
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• 제17권12호
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• pp.1736-1740
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• 2004

Since the application of relatively high levels of heavy metals in the compost poses a potential hazard to plants and animals, the content of heavy metals in the compost with animal manure is important to know if it is as a fertilizer. Measurement of heavy metals content in the compost by chemical methods usually requires numerous reagents, skilled labor and expensive analytical equipment. The objective of this study, therefore, was to explore the application of near-infrared reflectance spectroscopy (NIRS), a nondestructive, cost-effective and rapid method, for the prediction of heavy metals contents in compost. One hundred and seventy two diverse compost samples were collected from forty-seven compost facilities located along the Han river in Korea, and were analyzed for Cr, As, Cd, Cu, Zn and Pb levels using inductively coupled plasma spectrometry. The samples were scanned using a Foss NIRSystem Model 6500 scanning monochromator from 400 to 2,500 nm at 2 nm intervals. The modified partial least squares (MPLS), the partial least squares (PLS) and the principal component regression (PCR) analysis were applied to develop the most reliable calibration model, between the NIR spectral data and the sample sets for calibration. The best fit calibration model for measurement of heavy metals content in compost, MPLS, was used to validate calibration equations with a similar sample set (n=30). Coefficient of simple correlation (r) and standard error of prediction (SEP) were Cr (0.82, 3.13 ppm), As (0.71, 3.74 ppm), Cd (0.76, 0.26 ppm), Cu (0.88, 26.47 ppm), Zn (0.84, 52.84 ppm) and Pb (0.60, 2.85 ppm), respectively. This study showed that NIRS is a feasible analytical method for prediction of heavy metals contents in compost.

• 생물환경조절학회지
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• 제14권3호
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• pp.144-148
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• 2005

케일 잎의 내적 품질 중 비타민 C, 질산염, P, Ca, Mg, Fe 함량은 기존의 보고와 유사하였고, 이중 채소 품질로서 가장 큰 관심이 되고 있는 질산염은 100g 생체 중 139${\~}$429 mg으로 나타났으며, 비타민 C 함량은 역시 생체 100g당 106${\~}$203 mg으로 나타났다. 상대적 엽록소 함량과 케일 잎의 내적품질과 엽색과의 관계를 분석해 본 결과 상대적 엽록소와 b 수치가 내적 품질 중 질산염, 마그네슘, 철과 같은 엽록소와 관계 깊은 요인, 그리고 비타민 C 함량과 높은 상관관계를 보였다. 이 중 질산염 함량은 상대적 엽록소 함량과 r = $0.910^{{\ast}{\ast}}$ (질산염 함량 =$5.907^{{\ast}{\ast}}$ 상대적 엽록소 함량 + 21.55), 그리고 b 수치와는 r = $-0.901^{{\ast}{\ast}}$의 고도의 음의 상관관계를 나타내었다. 비타민 C 함량도 상대적 엽록소와 r = $-0.858^{{\ast}{\ast}}$의 고도의 상관관계를 보였다. 내적 품질간의 상관관계에서는 질산염 함량이 적을수록 비타민 C함량이 높아져 r = $-0.795^{{\ast}{\ast}}$의 고도의 음의 상관관계를 보였다. 따라서 재배중 비파괴적인 상대적 엽록소 측정으로 케일 잎의 질산염 등의 내적 품질의 예측이 가능하며 이를 통한 시비관리로 보건적 가치가 높은 저 질산염, 고 비타민 C의 케일생산이 가능해 질 것이라 생각된다.

• 분석과학
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• 제16권5호
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• pp.1041-1051
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• 2003

즉발감마선 중성자방사화법 (PGAA)은 시료내 미량 및 주원소를 빠르게 비파괴적으로 분석하는 방법으로 주로 광물, 금속, 석탄, 시멘트, 석유, 코팅, 제지 등 다양한 산업체에서 실시간 분석법으로 매우 유용하다. 이 방법은 제약과 관련된 산업체 또는 연구업무에도 활용되며, 마약 또는 폭발물과 같은 위험물질의 탐지에도 이용되고 있다. 본 총설은 즉발감마선 중성자 방사화법의 현재의 기술현황과 앞으로 연구추진 경향에 대하여 서술하였다. PGAA 시스템은 중성자 선원, 증성자 핵반응으로부터 발생하는 즉발감마선을 측정하기위한 다중채널분석기와 A/D 변환기 등의 전자모듈과 고분해능 HPGe 검출기로 구성된다. 속중성자의 콤프턴 산란에 의한 높은 바탕값은 감마-감마 동시계수장치의 도입으로 개선될 수 있다. 현재 $^{252}Cf$를 사용한 즉발감마선 중성자 방사화 장치는 수용액중에 존재하는 원소들의 실시간분석을 위해 한국원자력연구소에서 개발중에 있다. 이 장치는 다양한 마약 및 폭발물 또는 화학무기의 탐지에도 응용될 수 있다.

• Journal of Biosystems Engineering
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• 제36권5호
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• pp.369-376
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• 2011

The overall goal of this study was to examine the feasibility of predicting firmness of pear fruit by analyzing laser-induced light backscattering images. Thirty-five image analysis characteristics extracted from the laser-induced light backscattering images were used to build partial least squares regression (PLSR) models for predicting firmness of pear fruit. Experiments were conducted with three sets of pear samples which were in same "Shingo" cultivar, harvested in a same season, but produced in different counties. In every experiments with fruit samples produced in a same county, the correlation coefficients of prediction ($r_p$) and root mean square errors of prediction (RMSEP) of the models were 0.550~0.761 and 4.039~6.154 N, respectively. In an experiment with mixed fruit samples produced in different counties, the $r_p$ and RMSEP of the model were 0.669 and 5.02 N, respectively. The experiment results indicate that the analysis of laser-induced light backscattering images could be a useful tool for predicting firmness of pear fruit nondestructively.

• 농업과학연구
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• 제47권4호
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• pp.995-1010
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• 2020

In this study, a multivariate analysis model of partial least square regression (PLSR) was developed to predict the moisture content of green peppers using hyperspectral imaging (HSI). In HSI, illumination is essential for high-quality image acquisition and directly affects the analytical performance of the visible near-infrared hyperspectral imaging (VIS/NIR-HSI) system. When green pepper images were acquired using a direct lighting system, the specular reflection from the surface of the objects and their intensities fluctuated with time. The images include artifacts on the surface of the materials, thereby increasing the variability of data and affecting the obtained accuracy by generating false-positive results. Therefore, images without glare on the surface of the green peppers were created using a polarization filter at the front of the camera lens and by exposing the polarizer sheet at the front of the lighting systems simultaneously. The results obtained from the PLSR analysis yielded a high determination coefficient of 0.89 value. The regression coefficients yielded by the best PLSR model were further developed for moisture content mapping in green peppers based on the selected wavelengths. Accordingly, the polarization filter helped achieve an uniform illumination and the removal of gloss and artifact glare from the green pepper images. These results demonstrate that the HSI technique with a polarized lighting system combined with chemometrics can be effectively used for high-throughput prediction of moisture content and image-based visualization.

• 산업식품공학
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• 제15권4호
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• pp.324-331
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• 2011

초분광영상을 이용하여 방울토마토의 전체 면에서 반사스펙트럼을 획득하였으며 숙도 등급(GN-RD)에 따른 스펙트럼의 차이를 관찰하였다. 방울토마토의 반사스펙트럼에서 클로로필에 의한 675 nm 영역의 흡수가 관찰되었고, 당과 수분의 영향으로 알려진 840 nm, 970 nm 영역에서 흡수가 관찰되었다. 특히 GN에서 RD 등급으로 숙도가 진행될수록 평균 스펙트럼의 경우 반사율이 낮아지는 경향이 관찰되었다. 총 8개의 전처리를 이용하여 전 숙도 등급의 시료에 적용한 PLS 회귀 분석에서 내부품질들 중 경도 예측모델이 가장 우수한 것으로 확인되었다. 이때 전처리는 평균값을 이용한 정규화이었으며 결정계수는 0.876, 그리고 SEP은 1.875kgf이었다. 당도의 경우는 최대값을 이용한 정규화에서 결정계수가 0.823과 SEP $0.388^{\circ}Bx$로 나타났으며, 산함량의 경우 최대값을 이용한 정규화에서 0.620의 결정계수와 0.208%의 SEP이 확인되었다. 상품성을 고려한 PK, LR, RD 등급의 시료에서 PLS 회귀 분석을 실시한 결과 내부품질 중 전체의 숙도 등급의 시료를 사용하여 예측한 결과보다는 전체적으로 다소 낮은 예측결과를 확인할 수 있었다. 내부 품질 중 경도에서 가장 높은 예측모델이 확인되었으며, 전처리는 일정 범위를 이용한 정규화이고 0.679의 결정계수와 $0.976^{\circ}Bx$의 SEP이 확인되었다. 당도는 최대값을 이용한 정규화에서 0.586의 결정계수와 0.546kgf의 SEP의 결과를 보였으며 산 함량은 Savitzky Golay의 2차 미분에서 0.547의 결정계수와 0.188%의 SEP을 보였다. 본 연구에서는 최근 연구 활용이 시작되고 있는 최신기술인 초분광 반사영상을 이용하여 방울토마토 내부품질인 경도, 당도, 산 함량 예측의 가능성을 확인하였다. 초분광 영상은 영상처리를 이용하여 외부의 결함 및 외부 착색도등도 측정할 수 있으므로 본 연구에서 수행한 내부품질 측정과 융합하여 복합적인 농산물 품질 선별기 개발에 활용할 수 있을 것으로 판단된다.