• Rapid Communication in Photoscience
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• v.4 no.2
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• pp.34-36
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• 2015

New spectroscopic characteristics of amorphous ferric hydroxide ($Fe(OH)_3$), interestingly in the near infrared (NIR) region, are presented in this study. The absorption spectrum of ferric hydroxide covers wide spectral regions from ultraviolet to NIR (200~900 nm). Unique emission bands were newly observed in the NIR regions (800~1400 nm). Several bands of this NIR emission are quiet well overlapped with the combinational vibrational absorption bands of water. From photothermal conversion study, very interestingly, temperature of aqueous mixture solution including the amorphous ferric hydroxide was significantly increased from ambient temperature to $38^{\circ}C$ for 30 minutes under irradiation of a standard helium lamp.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.89.1-89.1
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• 2012

Type Ia Supernovae are known as one of the most reliable standard candle regarding to our understanding their explosion mechanism. Recently NIR photometry of SN Ia shows us better promise on the distance measurement. NIR peak luminosity is relatively independent of light curve shape and effect of extinction is obviously less than in optical wavelengths. Among NIR bands, Y-band photometry is suggested to have less scatter and reduced reddening effect than other NIR wavelengths, furthermore it is still unexplored regime to verify its utility. Here we report Y-band light curve analysis of M101 SN Ia to investigate how Y-band can help us to determine accurate distance to the galaxy.

• Bulletin of the Korean Chemical Society
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• v.22 no.1
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• pp.37-42
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• 2001

Ridge regression is compared with multiple linear regression (MLR) for determination of Research Octane Number (RON) when the baseline and signal-to-noise ratio are varied. MLR analysis of near-infrared (NIR) spectroscopic data usually encounters a collinearity problem, which adversely affects long-term prediction performance. The collinearity problem can be eliminated or greatly improved by using ridge regression, which is a biased estimation method. To evaluate the robustness of each calibration, the calibration models developed by both calibration methods were used to predict RONs of gasoline spectra in which the baseline and signal-to-noise ratio were varied. The prediction results of a ridge calibration model showed more stable prediction performance as compared to that of MLR, especially when the spectral baselines were varied. . In conclusion, ridge regression is shown to be a viable method for calibration of RON with the NIR data when only a few wavelengths are available such as hand-carry device using a few diodes.

• Bulletin of the Korean Chemical Society
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• v.20 no.9
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• pp.1021-1025
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• 1999

Near-infrared (NIR) spectroscopy has been successfully utilized for the rapid identification of six typical petroleum products such as light straight-run (LSR), naphtha, kerosine, light gas oil (LGO), gasoline, and diesel. The spectral features of each product were reasonably differentiated in the NIR region, and the spectral differences provided enough qualitative spectral information for discrimination. For discrimination, principal component analysis (PCA) combined with Mahalanobis distance was used to identify each petroleum product from NIR spectra. The results showed that each product was accurately identified with an accuracy over 95%. Most noticeably, LSR, kerosine, gasoline, and diesel samples were predicted with identification accuracy of 99%. The overall results ensure that a portable NIR instrument combined with a multivariate qualitative discrimination method can be efficiently utilized for rapid and simple identification of petroleum products. This is especially important when local at-site measurements are necessary, such as accidental petroleum leakage and regulation of illegal product blending.

• Journal of the Korean Wood Science and Technology
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• v.45 no.4
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• pp.399-408
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• 2017

Research on the rapid and accurate prediction of physical properties of wood using near-infrared (NIR) spectroscopy has attracted recent attention. In this study, partial least squares analysis was performed between NIR spectra and air-dried specific gravity of five domestic conifer species including larch (Larix kaempferi), Korean pine (Pinus koraiensis), red pine (Pinus densiflora), cedar (Cryptomeria japonica), and cypress (Chamaecyparis obtusa). Fifty different lumbers per species were purchased from the five National Forestry Cooperative Federations of Korea. The air-dried specific gravity of 100 knot- and defect-free specimens of each species was determined by NIR spectroscopy in the range of 680-2500 nm. Spectral data preprocessing including standard normal variate, detrend and forward first derivative (gap size = 8, smoothing = 8) were applied to all the NIR spectra of the specimens. Partial least squares analysis including cross-validation (five groups) was performed with the air-dried specific gravity and NIR spectra. When the performance of the regression model was expressed as $R^2$ (coefficient of determination) and root mean square error of calibration (RMSEC), $R^2$ and RMSEC were 0.63 and 0.027 for larch, 0.68 and 0.033 for Korean pine, 0.62 and 0.033 for red pine, 0.76 and 0.022 for cedar, and 0.79 and 0.027 for cypress, respectively. For the calibration model, which contained all species in this study, the $R^2$ was 0.75 and the RMSEC was 0.37.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.4
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• pp.278-283
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• 2001

The overall objective of this research was to show a NIR soil analyzer assessing soil fertility by measuring soil properties rapidly. A total of 140 soil samples were used to obtain calibrations and validation estimating soil properties. The soil samples were ground to pass 0.2mm sieve openings. Partial least square regression analysis was used to develop a calibration for soil analysis. The results indicated that NIR soil analyzer could be used as a routine method for quantitatively determining pH, OM, total nitrogen, CEC, extractable Ca, Mg, K, available $SiO_2$ and soil moisture simultaneously within one minute. Therefore, the NIR soil analyzer may be suitable for quick estimation of soil fertility estimation in fertilizer assessments.

• Journal of the Korean Society of Tobacco Science
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• v.28 no.2
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• pp.111-116
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• 2006

It is very important to add uniformly casing materials on tobacco for taste and flavor. However, analysis of casing materials was spent much time, effort and money. The object of this study was the development of a rapid method for the determination of glycerine, propylene glycol(PG), sucrose, glucose, fructose and water in the casing materials using the NIR transmittance method. Hundreds of calibration samples, with extended ranges (50%, 75%, 100%, 125%, and 150% of standard addition) in each constituent, were prepared in the casing materials at the various temperatures $(25^{\circ}C\;and\;30^{\circ}C)$. Calibration equation was developed by modified partial least square (MPLS) method using second derivative. The standard error of calibration and $R^2$ between added value and NIR estimated value results were $0.007{\sim}0.034\;and\;0.996{\sim}1.000$ for the casing sample set, respectively. The standard error of prediction and R2 between added value and NIR estimated value results were $0.010{\sim}0.034\;and\;0.997{\sim}1.000$ for the casing sample set, respectively. The analysis result was not different significantly between the NIR and added value. These results show that the NIR measurement system is an effective tool to ensure quality on the casing materials.

• Horticultural Science & Technology
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• v.29 no.3
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• pp.232-239
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• 2011

The genus Acorus is known as an indigenous medicinal plant. Genetic diversity of thirteen accessions of A. calamus and eight of A. gramineus, with an accession of Colocasia antiquorum and two of Iris pseudacorus as outgroups, were evaluated using RAPD markers for cluster analysis and principal coordinate analysis, and NIR spectroscopic profiles for principal component analysis.A total of 371 polymorphic bands were obtained by using the selected 12 random primers. The genetic distances were estimated from 0.03 to 0.31 within A. calamus and from 0.03 to 0.51 within A. gramineus. The dendrogram and three-dimensional plot separated the accessions into four distinct groups (A. calamus, A. gramineus, C. antiquorum, and I. pseudacorus). Moreover, for the diversity among genus Acorus, eleven A. calamus accessions, one A. gramineus accession, and two I. pseudacorus accessions were non-destructively analyzed from their leaves by NIR spectroscopy, which discriminated Acorus accessions like the RAPD analysis. Interestingly, thirteen accessions of A. calamus were clustered into two groups based on RAPD and NIR analyses, which indicates that there are two ecotypes of A. calamus in Korea. An accession (CZ) of A. calamus with yellow stripe on leaves was closely grouped with another (CX) at a genetic distance (GD) of 0.03, which shows that the stripe trait might be generated by chimeric mutation. The genetic distance between A. calamus and A. gramineus was revealed to be farthest from 0.80 to 0.88 GD. In genus Acorus the genetic diversity and genetic variation were identified by using RAPD marker technique and non-destructive NIRs.

• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.527-530
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• 2004

Adulteration of sesame oil using near infrared (NIR) spectroscopy was determined. Vegetable oils including sesame oil were scanned on the NIR spectrophotometer at 400-2500 nm. Partial least square (PLS) was applied on the standardized full NIR spectral data. Discriminant analysis with PLS is adequate for determination of sesame oil adulteration, except with decreasing adulteration rate. Designing of quality control system, which uses NIR spectroscopy to measure adulteration level of sesame oil is thus possible, although more work is required to give acceptable accuracy level.

• YAKHAK HOEJI
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• v.47 no.6
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• pp.461-468
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• 2003

A method is described for measuring clinically relevant levels of glucose in a pH 7.4 phosphate buffer by nearinfrared (NIR) absorption spectroscopy. Three types of NIR spectrometer, dispersive type, photo-diode array (PDA) type, and fourier transform (FT) type spectrometer were used and the performance was compared. Spectra were collected with a cuvette cell or quartz liquid fiber of 1 mm or 2 mm optical pathlength as transmittance method. Glucose absorption band appeared at second overtone, first overtone, and combination region for all systems. By use of the multivariate technigue of partial least squares (PLS) regression, glucose concentrations can be determined with a 16, 44, and 9.1 mg/d l standard error of prediction for dispersive type, photo-diode array type, and fourier transform type system, respectively. Sensitivity of spectrometer was evaluated by absorbance for the difference of 10 mg/d l glucose. Three absorption bands, second overtone, first overtone, and combination region were suited to three types systems, dispersive type, photo-diode array type, and fourier transform type systems, respectively. This investigation showed that three types NIR spectrometer were proper method for identification and quantitative analysis of glucose and possible for noninvasive blood glucose monitoring.