• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.11
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• pp.699-704
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• 2017

The amount of electric power for photovoltaic power generation depends on the location of the power plant and the direction of solar cell. The solar cell controls the generation of solar power plants. Therefore, the structure of solar cell, manufacturing method, and optic technology were factors contributing to increased solar cell efficiency; however, the technical limit has been reached. Herein, we propose a new method to increase the solar cell efficiency using a wavelength conversion technology that converts ultraviolet and infrared rays, which are not effectively used in solar cells, into effective wavelength of solar cell. We used fluoride $Na(Ca)YF_4$ phosphor for wavelength conversion. Then, a wavelength-conversion fluorescent paste, prepared using an organic-silicon binder, was used to prepare a film that was applied to Si solar cells. It was confirmed that conversion efficiency improved by 5% or more.

• YAKHAK HOEJI
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• v.49 no.2
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• pp.115-121
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• 2005

In this study, the performance of a portable NIR system and a FT NIR spectrometer were compared to determine water content of hairless mouse skin. The stratum corneum parts wer e separated from the epidermal tissues by trypsin solution. NIR diffuse reflectance spectra of hairless mouse skin were acquired using a fiber optic probe. In the near infrared, water molecules show two clear absorption bands at 1450 nm from first overtone of O-H stretching and 1940 nm from the combination involving O-H stretching and O-H deformation. It was found that the variations of O-H absorption band according to water content. Partial least squares regression (PLSR) was applied to develop a calibration model. The PLS model showed a good correlation between NIR predicted value and the absolute water content of separated hairless mouse skin, in vitro. For both the portable and the FT NIR spectrometer, These studies showed the possibility of a rapid and nondestructive skin moisture measurement using NIR spectroscopy. The portable NIR spectrometer with a photodiode arrays-microsensor could be more rapidly applied for the determination of water content with comparable accuracy with the performance of a FT spectrometer .

• Current Optics and Photonics
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• v.7 no.3
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• pp.297-303
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• 2023

In this paper, we demonstrated a high-energy (285 mJ) mid-infrared flashlamp-pumped electro-optically 𝚀-switched Er:YAG master oscillator power amplifier (MOPA) system and comprehensively investigated its temporal, spectral, and spatial characteristics. To increase the output energy, we optimized the delay between the timings at which the flashlamps of the master oscillator and power amplifier were triggered. In addition, the output energy was improved while minimizing thermal effects by cooling the MOPA system to a temperature slightly above the dew point. Consequently, the MOPA structure boosted the output energy without damaging the lithium niobate Pockels cell, which is a crucial element in 𝚀-switching. This design realized pulses with energies up to 0.285 J and pulse durations of approximately 140 ns at a wavelength of 2,936.7 nm. This high-energy mid-IR Er:YAG MOPA system can be used for various scientific, engineering, and military underwater applications.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.29 no.5
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• pp.208-214
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• 2019

The glass of $BaO-GeO_2-La_2O_3-ZnO$ system with a transmittance of more than 75 % at mid-wave infrared (MWIR) region in the range of $3{\mu}m$ to $5{\mu}m$ is manufactured and its property is evaluated. After selecting construction that can melt glass through flow button test, $BaO-GeO_2-La_2O_3$ system where 10 mol%, 20 mol% of ZnO were added respectively were melted at $1350^{\circ}C$ for 1 hour and $BaO-GeO_2-La_2O_3$ system of glass was manufactured. Among them, with 20 mol% of ZnO, 16 mol% BaO-56 mol% $GeO_2-8mol%$ $La_2O_3-16mol%$ ZnO system of glass was found to has less than $660^{\circ}C$ of glass transition temperature, more than 1.70 of refractive index, and more than 530 of knoop hardness. Therefore, it is concluded that glass of $BaO-GeO_2-La_2O_3-ZnO$ system of glass with 20 mol% ZnO has good melting conditions at low temperatures and excellent optical properties, thus, can be utilized for special optical materials field.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.40.2-40.2
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• 2010

The Solar Daylighting Technology is considered with the plan that will be able to embody the energy technology which is possible to continue. Daylighting has an considerable advantage of the high effectiveness and the various use because daylighting can use the infrared ray, the visible ray and the ultraviolet rays without energy transformation. In this study, the experiment is tried of making the shape and an arrangement of the reflector different After establishing the reflector in the height(10m) which is fixed. It's also researched on the shape of the efficient reflector using the program(Trace Pro) at the time of the autumnal equinox and the winter solstice at fixed hours.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.2202-2208
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• 2010

The railway in Korea has been one of important transportation means as the introduction of high-speed train and progress in subway systems. Also, as increases in the speed of train, the guarantee of safety becomes more important, especially, in the fields of railway vehicles and/or facilities. The structural health evaluation for the prevention and diagnosis of the accidents could be conducted using several types of nondestructive evaluation techniques such as ultrasonic developed using infrared thermography or optic fiber sensors. In this paper, the recent progress in structural health evaluation for railway systems has been introduced, and the case studies have been discussed.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.279.1-279.1
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• 2003

NIR reflectance spectroscopy, using a fiber-optic probe was used to determine rapidly and non-destructively the content of ambroxol in intact ambroxol 30 mg (nominal content 12.5％ m/m ambroxol) tablets by collecting NIR spectra in range 1100 - 1750 nm and using PLSR calibration method. The tablets (10.3 - 15.9％ m/m ambroxol, i.e., 82 - 127％ of the nominal label content) were used 7 calibration set and 5 validation set. (omitted)

• Investigative Magnetic Resonance Imaging
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• v.25 no.4
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• pp.218-228
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• 2021

Due to their high degree of freedom to transfer and acquire light, fiber optics can be used in the presence of strong magnetic fields. Hence, optical sensing and imaging based on fiber optics can be integrated with magnetic resonance imaging (MRI) diagnostic systems to acquire valuable information on biological tissues and organs based on a magnetic field. In this article, we explored the combination of MRI and optical sensing/imaging techniques by classifying them into the following topics: 1) functional near-infrared spectroscopy with functional MRI for brain studies and brain disease diagnoses, 2) integration of fiber-optic molecular imaging and optogenetic stimulation with MRI, and 3) optical therapeutic applications with an MRI guidance system. Through these investigations, we believe that a combination of MRI and optical sensing/imaging techniques can be employed as both research methods for multidisciplinary studies and clinical diagnostic/therapeutic devices.

• Journal of Advanced Navigation Technology
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• v.21 no.6
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• pp.638-642
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• 2017

FOD is a generic term for substances with potential threats that can pose a fatal risk to aircraft. Therefore, FOD should be noted in all areas of the airport. Especially, the method of detecting and collecting FOD in runway and aircraft movements is very low efficiency and economical efficiency of airport operation, so it is essential to develop FOD automatic detection system suitable for domestic environment. As part of the aviation safety technology development project, the development of an automatic detection system for foreign matter in the moving area of the aircraft inside the airport is underway. In this paper, it is confirmed that EO / IR camera is used for detection of foreign objects at Taean Airfield of Hanseo University. EO camera is used during the day and IR camera is used at night.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.472-477
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• 2017

Oil spills cause a lot of damage to the environment. Oil destroys the water environment and ecosystem in a very short period of time once they are contaminated by it, it takes a lot of time to recover from the contamination and the cleaning process is very difficult. Therefore, oil detectors are greatly needed as they can monitor any oil spills over the sea, rivers, and lakes. There are two kinds of technology available for detecting oil, viz. the contact and non-contact types. The former is based on the use of the conductivity, capacitance and microwaves, while the latter employs infrared, UV, laser, optic and radar technologies. As there are also various hurdles in the measuring of oil on water, such as the presence of waves, refraction of light, temperature and saltiness, it is imperative to select the right oil detector which is appropriate for the specific environment. In this study, a contact type oil detector is developed, which can be used in oil related industries, such as refineries, petrochemical companies, and power generation stations. The detector is made up of the sensor module, which floats on the water, and the controller which processes the signal coming from the sensor module and displays it. It is designed in such a way that the existence of oil is detected through the sensor and the change in the permittivity is observed to determine the volume and type of spilled oil.