• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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• pp.1354-1363
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• 1993

Optical methods were developed to examine their feasibility for quality evaluation of peanut with pod. Surface color and internal quality of peanut were measured without contact. The surface color of peanut was measured by light reflectance at a region of visible wavelengths. Its characteristic was high correlated with a visual grading of peanut. A trial machine for the color grading of peanut was developed using an optical sensor and it was considered to compare with the visual grading. The spectral reflectance at a region of near infrared wavelengths from 1,200 to 2,500nm was measured , and the chemical components of peanut were related to spectral reflectance at special wavelengths. The protein, fat and moisture contents of peanut were estimated by the near infrared methods. An infrared imaging method was developed to evaluate the internal quality of peanut with pod. As thermal characteristic of peanut with pod was deeply related to internal quality , the quality of peanut can be evaluated by temperature changes on the surface of peanut. Measurement of surface color, near infrared reflectance and thermal imaging were shown to be very effective in grading of peanut with pod.

• International journal of advanced smart convergence
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• 제9권4호
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• pp.203-208
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• 2020

In this paper, we propose the design and implementation of a desktop LED stand and smart app that automatically adjusts color temperature and illuminance for optimal brightness and eye health by improving the structural problem of the LED stand. It is a tabletop LED stand that supports optimal brightness through color temperature control and heat transfer through infrared LED to relieve eye strain through blood circulation and muscle movement. The LED stand works with the smartphone to automatically adjust the optimal brightness and color temperature for the user's environment. In addition, the brightness of the infrared LED is adjusted to a living frequency of 4Hz to relax the eye muscles and reduce eye strain. This study implemented an effective measured data-based system of previous studies through the color temperature and illumination of LED lighting, and near-infrared rays, and presented meaningful results by conducting an experiment to prove the effect through subjects.

• 비파괴검사학회지
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• 제37권2호
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• pp.91-98
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• 2017

Recently, composite materials have been mainly used in the main wings, ailerons, and fuselages of aircraft and rotor blades of helicopters. Composite materials used in rapid moving structures are subject to impact by hail, lightning, and bird strike. Such an impact can destroy fiber tissues in the composite materials as well as deform the composite materials, resulting in various problems such as weakened rigidity of the composite structure and penetration of water into tiny cracks. In this study, experiments were conducted using a 2 kW halogen lamp which is most frequently used as a light source, a 2 kW near-infrared lamp, which is used for heating to a high temperature, and a 6 kW xenon flash lamp which emits a large amount of energy for a moment. CFRP composite sandwich panels using Nomex honeycomb core were used as the specimens. Experiments were carried out under impact damages of 1, 4 and 8 J. It was found that the detection of defects was fast when the xenon flash lamp was used. The detection of damaged regions was excellent when the halogen lamp was used. Furthermore, the near-infrared lamp is an effective technology for showing the surface of a test object.

• 천문학논총
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• 제32권1호
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• pp.63-65
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• 2017

The zodiacal light emission is the thermal emission from the interplanetary dust and the dominant diffuse radiation in the mid- to far-infrared wavelength region. Even in the far-infrared, the contribution of the zodiacal emission is not negligible at the region near the ecliptic plane. The AKARI far-infrared all-sky survey covered 97% of the whole sky in four photometric bands with band central wavelengths of 65, 90, 140, and $160{\mu}m$. AKARI detected the small-scale structure of the zodiacal dust cloud, such as the asteroidal dust bands and the circumsolar ring, in far-infrared wavelength region. Although the most part of the zodiacal light structure in the AKARI far-infrared all-sky image can be well reproduced with the DIRBE zodiacal light model, there are discrepancies in the small-scale structures. In particular, the intensity and the ecliptic latitude of the peak position of the asteroidal dust bands cannot be reproduced precisely with the DIRBE models. The AKARI observational data during more than one year has advantages over the 10-month DIRBE data in modeling the full-sky zodiacal dust cloud. The resulting small-scale zodiacal light structure template has been used to subtract the zodiacal light from the AKARI all-sky maps.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.1544-1545
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• 2006

• 대한의용생체공학회:의공학회지
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• 제44권6호
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• pp.450-464
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• 2023

Pulse oximetry, a non-invasive technique for evaluating blood oxygen saturation, conventionally depends on isolated measurements, rendering it vulnerable to factors like illumination profile, spatial blood flow fluctuations, and skin pigmentation. Previous efforts to address these issues through imaging systems often employed red and near-infrared illuminations with distinct profiles, leading to inconsistent ratios of transmitted light and the potential for errors in calculating spatial oxygen saturation distributions. While an integrating sphere was recently utilized as an illumination source to achieve uniform red and near-infrared illumination profiles on the sample surface, its bulkiness presented practical challenges. In this work, we have enhanced the pulse oximetry imaging system by transitioning illumination from an integrating sphere to a multi-wavelength LED configuration. This adjustment ensures simultaneous emission of red and near-infrared light from the same position, creating a homogeneous illumination profile on the sample surface. This approach guarantees consistent patterns of red and near-infrared illuminations that are spatially uniform. The sustained ratio between transmitted red and near-infrared light across space enables precise calculation of the spatial distribution of oxygen saturation, making our pulse oximetry imaging system more compact and portable without compromising accuracy. Our work significantly contributes to obtaining spatial information on blood oxygen saturation, providing valuable insights into tissue oxygenation in peripheral regions.

• Bulletin of the Korean Chemical Society
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• 제20권9호
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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.

• 천문학회보
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• 제32권1호
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• pp.99.2-99.2
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• 2007

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.2101-2101
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• 2001

Near-infrared spectroscopy is now being used in clinical diagnosis as a non-invasive monitor of tissue oxygenation state. However, due to lack of the optical pathlength information within tissues, it is still difficult to quantitate the hemoglobin concentration with present CW techniques. Time-resolved spectroscopy (TRS), which measures temporal profiles of emerging light from tissues, enables to estimate the pathlength distribution within tissues by converting time to distance. Consequently, quantitative measurement of tissue oxygenation is possible by analyzing the data with optical diffusion equation 1) or our Microscopic Beer-Lambert law2). Time-Resolved Spectroscopy System : TRS-1O3) Our TRS-10 system consists of a three-wavelength (759, 797, 833 nm) PLP as pulsed light source, a high speed PMT with high sensitivity and three signal-processing circuits for time-resolved measurement (CFD/TAC, A/D converter and histogram memory). Optical pulse train consisting of 759, 797 and 833nm is generated by PLP at 5㎒ repetition rate and irradiated a sample through a single optical fiber. The diffuse-reflected light from the sample is collected by a bundle fiber and then detected by the PMT for single photon measurement. After being amplified by a following fast amplifier, the electrical signals for each wavelength are picked out by CFD/TAC module. Then, a signal processing circuit integrated the TRS data for each wavelength individually. The simultaneous TRS measurement for three wavelengths achieved without any optical or mechanical switch. Experiment and Results Input and detection fibers of TRS-10 were attached at the human forehead with a fiber separation of 3cm. TRS measurements were continuously performed for about 20 minutes including 2 minutes hyper ventilation. It was observed that the total hemoglobin concentration was decreasing during the hyper ventilation and recovered until 2 minutes after hyper ventilation. On the other hand, the deoxy-hemoglobin concentration began to increase after hyper ventilation and had its peak at around 2 minute later, showing 502 drop from 75% to 60% due to inhibition of breathing by performing hyper ventilation. The results showed that this system might be able to quantitate the concentrations of oxy- and deoxy-hemoglobin in the human brain.

• 한국전자통신학회논문지
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• 제16권5호
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• pp.991-1000
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• 2021

비침습식 혈당 검출 기술 중 광학 기법은 생물학적 매체를 통과할 때 빛의 반사와 흡수 및 산란 특성을 이용하는 방법으로 통증이나 측정의 불편함을 감소시키고 감염 위험이 없어 혈당 검출 연구의 주요 흐름이 되고 있다. 이 중 근적외선 분광법은 혈당 분자와 유사한 흡수 기능을 공유하는 단백질과 산의 간섭들로 감지된 신호 분석 시 복잡성이 증가하는 단점이 있다. 본 연구에서는 근적외선의 피부 흡수로 발생할 수 있는 혈당검출 기능저하를 완화시키기 위해 다중 근적외선 대역의 비침습식 센서시스템을 설계하고 제작하였다. 제작한 시스템의 검증을 위해 혈액 조사를 실시하였으며, 혈액 내의 혈당 반응 정도를 스펙트럼 데이터로 수집하고, 데이터와 혈당과의 상관관계 관점에서 정량적으로 본 연구의 성과를 검증하였다.