• 천문학회보
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• 제41권1호
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• pp.76.2-76.2
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• 2016

We present near-infrared (0.8 - 1.8 microns) spectra of 63 bright (J_mag < 10) stars observed with Low Resolution Spectrometer (LRS) onboard the rocket-borne Cosmic Infrared Background Experiment (CIBER). Two Micron All Sky Survey (2MASS) photometry information is used to find cross-matched stars after reduction and extraction of the spectra. We identify the spectral types of observed stars by comparing with spectral templates from the Infrared Telescope Facility (IRTF) library. All the observed spectra are consistent with late F to M stellar spectral types, and we identify various infrared absorption lines. As our observations are performed above the Earth's atmosphere, our spectra are free from telluric contamination. Including HST/NICMOS and Cassini/VIMS, the spectral coverage has rarely been achieved in space, and the methods developed here can inform statistical studies with future low-resolution spectral measurements such as GAIA photometric and radial velocity spectrometer.

• 한국세라믹학회지
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• 제36권9호
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• pp.915-922
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• 1999

Microwave dielectric properties and far infrared reflectivity spectra of the (Zr0.8Sn0.2)TiO4 ceramics were inves-tigated with the various cooling rate. Dielectric constant was nearly same value while the unloaded Q value was largely affected by cooling rate. The Q.f of 42,140 at 7 GHz was obtained for the specimens with cooling rate of 1$^{\circ}C$/min. The effect of the cooling rate on the change of the ionic the electronic polarization and the intrinsic microwave loss of the specimens were investigated by the infrared reflectivity spectra from 50 to 4000cm-1 which were calculated by Kramers-Kroning analysis and the classical oscillator model. The relative tendency of microwave dielectric properties of the specimens calculated from the relfectivity data were in good agreement with the results by the post resonant method.

• Bulletin of the Korean Chemical Society
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• 제13권2호
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• pp.148-155
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• 1992

Computerized interpretation of vapor phase infrared spectra using a novel expert system approach for spectra/structure correlation for vapor phase spectra is introduced. Rapid identification of aromatic functional groups of components in gaseous mixture can be achieved using this expert system.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1284-1284
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• 2001

The transesterification of molten ethylene/vinylacetate (EVA) copolymers by octanol as a reagent and sodium methoxide as a catalyst in an extruder has been monitored by on-line near infrared (NIR) spectroscopy. A total of 60 NIR spectra were acquired for 37 minutes with the last spectrum recorded 31 minutes after the addition of octanol and catalyst was stopped. The experimental spectra show strong baseline fluctuations which are corrected for by multiplicative scatter correction (MSC). The chemometric methods of orthogonal projection approach (OPA) and multivariate curve resolution (MCR) were used to resolve the spectra and to derive concentration profiles of the species. The detailed analysis reveals the absence of completely pure variables that leads to small errors in the calculation of pure spectra. The initial estimation of a concentration that is necessary as an input parameter for MCR also presents a non-trivial task. We obtained results that were not ideal but applicable for practical concentration control. They enable a fast monitoring of the process in real-time and resolve the spectra of the EVA copolymer and the ethylene/vinyl alcohol (EVAL) copolymer to be very close to the reference spectra. The chemometric methods used and the decomposed spectra are discussed in detail.

• Bulletin of the Korean Chemical Society
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• 제25권9호
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• pp.1423-1426
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• 2004

• 대한화학회지
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• 제39권3호
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• pp.213-217
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• 1995

수용액상에서 BUDDA(Butyldithiodiacetic acid), BMDDA(Benzmethyldithiodiac-etic acid), CHDDA(Cyclohexyldithiodiacetic acid)의 IR 스펙트라는 다양한 pH값에서 보고되어진다. 이온화된 carboxyl group과 비이온화된 carboxyl group의 비대칭 신축진동 흡수띠 차이를 이용하여 free-ligand의 구조를 추정한다. 또한 이들 연구의 접근은 리간드의 IR 스펙트라와 전위차 적정법을 이용하여 얻어진 $pk_a$값을 비교함으로서 설명된다.

• 한국작물학회지
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• 제53권3호
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• pp.314-319
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• 2008

Near infrared (NIR) spectroscopy was used to classify normal and artificially aged nonviable corn (Zea mays L., cv. 'Suwon19') seeds. The spectra at 1100-2500nm were scanned with normal and artificially aged single seeds and analyzed by principle component analysis (PCA). To discriminate normal seeds from artificially aged seeds, a calibration modeling set was developed with a discriminant partial least square 2 (PLS 2) method. The calibration model derived from PLS 2 resulted in 100% classification accuracy of normal and artificially aged (aged) seeds from the raw, the 1st and 2nd derivative spectra. The prediction accuracy of the unknown normal seeds was 88, 100 and 97% from the raw, the $1^{st}$ and $2^{nd}$ derivative spectra, and that of the unknown aged seeds was 100% from all the raw, the $1^{st}$ and $2^{nd}$ derivative spectra, respectively. The results showed a possibility to separate corn seeds into viable and non-viable using NIR spectroscopy.

• 약학회지
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• 제13권2_3호
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• pp.51-56
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• 1969

In quantitative analysis of sulfonamide drugs by means of infrared Spectrophotometry, the author tried to analyse Sulfamethoxydiazine and Sulfamethoxypyridazine in their Pharmaceutical Preparations. By the survey of infrared absorption spectra of Sulfamethoxydiazine and Sulfamethoxypyridazine. We found quantitative properties at the peaks of wave number 1150 cm$^{-1}$ (Sulfamethoxydiazine) and 1090 cm$^{-1}$ (Sulfamethoxypyridazine) in the spectra. These peaks obey Beer's Law in a range of 50-150 ug for Sulfamethoxydiazine and 70-350 ${\mu}$g for Sulfamethoxypyridazine in 300 mg KBr disc. By this method, Sulfamethoxydiazine and Sulfamethoxypyridazine could be analyzed less than 2% error.

• Journal of the Korean Wood Science and Technology
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• 제47권1호
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• pp.101-109
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• 2019

This paper examines the classification of five coniferous species, including larch (Larix kaempferi), red pine (Pinus densiflora), Korean pine (Pinus koraiensis), cedar (Cryptomeria japonica), and cypress (Chamaecyparis obtusa), using near-infrared (NIR) spectra. Fifty lumber samples were collected for each species. After air-drying the lumber, the NIR spectra (wavelength = 780-2500 nm) were acquired on the wide face of the lumber samples. Soft independent modeling of class analogy (SIMCA) was performed to classify the five species using their NIR spectra. Three types of spectra (raw, standard normal variated, and Savitzky-Golay $2^{nd}$ derivative) were used to compare the classification reliability of the SIMCA models. The SIMCA model based on Savitzky-Golay $2^{nd}$ derivatives preprocessing was determined as the best classification model in this study. The accuracy, minimum precision, and minimum recall of the best model (PCA models using Savitzky-Golay $2^{nd}$ derivative preprocessed spectra) were evaluated as 73.00%, 98.54% (Korean pine), and 67.50% (Korean pine), respectively.

• Near Infrared Analysis
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• 제2권1호
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• pp.43-53
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• 2001

A non-invasive spectroscopic method is presented for the measurement of pulmonary edema. Both early diagnosis and quantitative edema estimates were investigated. The spectroscopic determination of pulmonary edema involved the acquisition of diffuse reflectance spectra in the near-infrared (NIR) region with change in water concentration - water is the main constituent of edema fluid. Pulmonary edema was induced into the excised perfused lungs of seven animals by elevating the hydrostatic pressure. Estimates of edema were ascertained from a partial least squares regression of the measured spectral response. Actual edema was determined from the change (increase) in total lung weight. Estimates in relative lung weight increases due to in vitro edema were made with the near infrared spectra. The results revealed that fluid accumulation produced spectral changes in the O-H and C-H absorptions as well as scattering changes in the spectra. Histology of the lung was used to verify the presence or absence of interstitial and alveolar edema. Results demonstrated that near infrared spectroscopy might provide a new tool for clinical assessment of pulmonary edema.