• ETRI Journal
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• v.27 no.4
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• pp.377-384
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• 2005

We investigate near-infrared light (NIR) propagation in a model of an adult head using an extensive Monte Carlo (MC) simulation. The adult head model is a four-layered slab which consists of a surface layer, a cerebrospinal fluid layer, a gray-matter layer, and a white-matter layer. We study the effects of a refractive index mismatch on the model, calculating the intensity of detected light, mean flight time, and partial mean flight time of each layer for various refractive indices of the cerebrospinal fluid layer as functions of source-detector spacing. The Monte Carlo simulation shows that the refractive index mismatch presents very rich results including rapidly decaying intensity of detected light and a peak and cross-over in the partial mean flight time with source-detector spacing. We also investigate spatial sensitivity profiles at various source-detector spacings, discussing the index mismatch effect on the model.

• Textile Coloration and Finishing
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• v.3 no.1
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• pp.25-27
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• 1991

New Series of diazaanthraquinone near-infrared dye was synthesised by the ring closure reaction between 2,3-dibromodiazaanthraquinone and potassium 2-aminobenzenethiololate. This dye absorbs near-infrared light at 780 nm.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2010.03a
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• pp.49-50
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• 2010

The near-infrared absorbing donor-acceptor chromophores have been investigated by varying the electron donating and accepting molecular moiety. A series of near-infrared absorbing chromophores were offered narrow and intense absorption band in a various organic solvents. The dyes synthesised were, however, strongly bathochromic shift which extended well into the near-infrared region. The functional uses of dyes are vast in number, and it is convenient to classify them in some way. In all cases, it is the $\Pi$-chromophore that plays a major role in the functional application. "Light absorption" is of course the most commonly used property of a dye chromophore, and it can be employed directly, e.g. in light filters and optical data recording, or it can be used to drive further functional processes, e.g. fluorescence, photochromism, photosensitization.

• Journal of Biomedical Engineering Research
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• v.40 no.4
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• pp.125-131
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• 2019

As a non-invasive method for alleviating allergic rhinitis, there has been a recent ongoing research in the treatment of light from light emitting diodes (LEDs) and lasers. A total of 15 subjects diagnosed with allergic rhinitis were selected for this study. Red and near infrared light emitted from LEDs with wavelengths of 660nm and 940nm were illuminated three times daily (three minutes per cycle) for a total of two weeks. The degree of nasal congestion, runny nose, sneezing and nasal itching was evaluated by questionnaires before and after the test. Also, the serum IgE (Immunoglobulin E) was measured and compared before and after the test. As a result, the total score of symptoms of allergic rhinitis was decreased by 67% after the test (P<0.01). The level of IgE was decreased by 17% after the test (P<0.05). In conclusion, the non-invasive LED phototherapy method using red and near-infrared LED light was effective in alleviating symptoms of allergic rhinitis. There were no adverse effects or complications reported during and after the test.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.23 no.4
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• pp.367-374
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• 2005

Recently, forest damage has occurred often and made big issues. Among them, the damage by forest fire is not only damage of itself but also being connected with secondary damage like a flood. This is the fact that a forest fire is caused rather artificially by people than nature. In this study, we try to investigate damage of a forest fire through spectral reflectance of a plant community surveyed using a near infrared CCD camera and a SPM (Spectral Radiometer) as advanced work to use satellite image data. That is, damage of a forest fire by the naked eye observation was divided into the No damage, the light damage, the serious damage and we estimated activity of forest and grasped revival possibility of forest. Through correlation analysis between the spectral reflectance by SPM and the near infrared CCD camera, we could get high correlation in the No damage and light damage. Therefore, when we surveyed damage of a forest fire, we could grasp damage, that is hardly observed by the naked eye by, using jointly the spectral radiometer and the near infrared CCD camera.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1271-1271
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• 2001

Water pollutants in drainage mainly consist of organic compounds. Hence, total organic carbon (TOC), chemical oxygen demand (COD), and biochemical oxygen demand (BOD) were generally used as the indices of pollution. However, these values are determined by special analyzer (TOC), titration method (COD), or microbe culture (BOD). Therefore, the development of simple and easy methods for the determination of water pollution is required. The authors reported the evaluation of water pollution by near infrared (NIR) spectroscopy in a model system with food components (Takamura et al. (200) Near Infrared Spectroscopy: Proceedings of 9th International Conference, pp. 503-507). In this study, the relationship between NIR spectra and drainage was investigated in order to develop a method for evaluation of drainage by NIR. Drainage was obtained in Nara Purification Center. The ranges of TOC, COD, and BOD were 0-130, 0-100 and 0-200, respectively. NIR transmittance spectra were recorded on NIR Systems Model 6250 Research Composition Analyzer in the wavelength range of 680-1235 and 1100-2500 nm with a quartz cell (light path: 0.5, 1, 2, 4 and 10mm) at 10-40. Statistical analysis was performed using NSAS program. A partial least squares (PLS) regression analysis was used for calibration. As the result, a good correlation between the raw NIR spectra and OC was obtained in the calibration. The best light path was 10 and 0.5mm in the wavelength range of 680-1235 and 110-2500nm, respectively. In the calibration, correlation coefficients(R) were 096-0.97 in the both range. In the prediction, however, a good correlation (R=0.89-0.96) was obtained only in the range of 6801235 nm, Similar results were obtained in the cases of COD and BOD. These results suggest the possibility that NIR spectroscopy can be used to evaluate drainage.

• Fashion & Textile Research Journal
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• v.7 no.6
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• pp.665-672
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• 2005

The purpose of this study was to assess the feasibility and the effects of near infrared lighted garments on thermo-physiological responses in human body. Seven healthy adult men were recruited for this study. All subjects were informed the contents and purpose of this study. The experiment was carried out in a climate chamber of $32^{\circ}C$, 60%RH with 'Rest', 'Exercise' and 'Recovery' period. The experimental garments consisted of briefs, undershirts(sleeveless), nightclothes, T-shirts, knee-trousers and socks. Subjects participated in two experiments, one was wearing near infrared lighted garments(NIR-O), the other was wearing regular garments(NIR-X). The order of experiment was randomized, and subjects wore experimental garments before 24 hours in order to benefit by near infrared light. Measurement items included rectal temperature ($T_{re}$), mean skin temperature ($\bar{T}_{sk}$), sweat rate, heart rate, oxygen uptake and subjective sensation. The results are as follows: As to the variation of rectal temperature and mean skin temperature, value of wearing NIR-X was higher than value of wearing NIR-O, indicating a significant level of difference (p<.001). Sweat rate under NIR-O and NIR-X condition were 575.35 g and 535.75 g, respectively. Heart rate value of NIR-X condition was higher than NIR-O. Oxygen uptake measured during experiment was the higher in NIR-X condition with significant difference (p<.001). In the subjective sensation, the value of NIR-O condition was higher than NIR-X condition without significantly difference.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.3101-3101
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• 2001

Near Infrared spectroscopy (NIR) used on human skin measurement was explored in the past decade. Many publications in different journals and magazines discussed the feasibility of the NIR technique for cosmetic product property studies. Based upon the results of pioneers, we have pursued some work of the NIR instrument coupled with a probe module for skin measurement in vivo and vitro. In part I of this paper, the specific Near Infrared spectroscopy instrument stability, human subject conditions and other parameters, which could affect the measurements reproducibility are discussed. Second derivative NIR spectra and Principle Components Analysis (PCA) are utilised for data interpretation. In part II of this paper, the relationship of human skin moisture and ageing, the gender information and finally, the discovery of penetration depth of NIR incident light on skin are reported. A theoretical penetration depth calculation equation is proposed. In part III, the study results of a couple of commercial skin care products effect will be described. The skin lotions were applied on human skin (in vivo) in order to exam the NIR feasibility to monitor the changes of moisture level. The results are consistently positive. From our primary study, it can conclude that the NIR is potentially a very powerful instrument for skin condition diagnostics, either for cosmetic and/or for medication purposes.

• Journal of Biomedical Engineering Research
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• v.28 no.2
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• pp.229-234
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• 2007

Diffuse optical tomography (DOT) is a relatively new medical imaging modality which uses near infrared light to image large-sized tissues noninvasively. We constructed a frequency-domain DOT system to measure the optical properties of optical phantoms and human tissues. The FD-DOT uses the intensity-modulated infrared light source that illuminates the biological tissues. The phase shift and modulation changes at each detector site are separately processed to measure the optical properties. The absorption and scattering coefficients are separately estimated using inverse algorithms.

• Journal of The Korean Astronomical Society
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• v.38 no.2
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• pp.149-151
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• 2005

We have studied the environmental effect on optical-NIR color gradients of 273 nearby elliptical galaxies. Color gradient is a good tool to study the evolutionary history of elliptical galaxies, since the steepness of the color gradient reflects merging history of early types. When an elliptical galaxy goes through many merging events, the color gradient can be get less steep or reversed due to mixing of stars. One simple way to measure color gradient is to compare half-light radii in different bands. We have compared the optical and near infrared half-light radii of 273 early-type galaxies from Pahre (1999). Not surprisingly, we find that $r_e(V)s$ (half-light radii measured in V-band) are in general larger than $r_e(K)s$ (half-light radii measured in K-band). However, when divided into different environments, we find that elliptical galaxies in the denser environment have gentler color gradients than those in the less dense environment. Our finding suggests that elliptical galaxies in the dense environment have undergone many merging events and the mixing of stars through the merging have created the gentle color gradients.