• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.1
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• pp.45-50
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• 2013

The reflector of infrared lamp is designed to the optimal circular shape through the analyses of lumination distributions with a triangular, rectangular and circular configurations of infrared lamps respectively by using Photopia. PLC is used to compare and amplify the difference between soldering temperature profile and feedback value. It is fed to IR lamp controller which adjusts the soldering temperature of PV cell. The soldering temperature measured using an infrared temperature sensor is then fed back to the PLC. The closed control loop of soldering temperature on a PV cell is implemented. The noncontact soldering device of PV cells using infrared lamp which is easily operated by HMI operation panel and controlled robustly by PLC and IR lamp controller is developed.

• Journal of Sensor Science and Technology
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• v.30 no.6
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• pp.446-450
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• 2021

Non-dispersive infrared (NDIR) gas sensors typically use an optical filter that transmits a discriminating 4.26 ㎛ wavelength band to measure carbon dioxide (CO2), as CO2 absorbs 4.26 ㎛ infrared. The filter performance depends on the transmittance and full width at half maximum (FWHM). This paper presents the fabrication, sensitivity, and selectivity characteristics of a distributed Bragg reflector (DBR)-based Fabry-Perot filter with a simple structure for CO2 detection. Each Ge and SiO2 films were prepared using the RF magnetron sputtering technique. The transmittance characteristics were measured using Fourier-transform infrared spectroscopy (FT-IR). The fabricated filter had a peak transmittance of 59.1% at 4.26 ㎛ and a FWHM of 158 nm. In addition, sensitivity and selectivity experiments were conducted by mounting the sapphire substrate and the fabricated filter on an NDIR CO2 sensor measurement system. When measuring the sensitivity, the concentration of CO2 was observed in the range of 0-10000 ppm, and the selectivity was measured for environmental gases of 1000 ppm. The fabricated filter showed lower sensitivity to CO2 but showed higher selectivity with other gases.

• Journal of Aerospace System Engineering
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• v.17 no.4
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• pp.1-9
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• 2023

Recently, as Synthetic Aperture Radar (SAR), communication, and signal surveillance missions of spacecraft have become more advanced, research has been actively conducted on the deployable large mesh antenna system with excellent storage efficiency compared to the deployment area, and light weight. Deployable Mesh antennae are characterized by an increase in the number of Openings Per Inch (OPI), which is a measure of mesh weaving density as the mission frequency band increases, and this OPI change directly affects the thermal optical properties of the mesh antenna, so research on this is required. In this paper, to verify the thermal relationship between the optical properties of the mesh and antenna reflector, thermal sensitivity analysis between the mesh and the antenna reflector is performed by in-orbit thermal analysis with various optical characteristics of the mesh based on existing overseas research cases. In addition, the temperature gradient effect of the mesh reflector is analyzed.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2001.05a
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• pp.215-218
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• 2001

본 연구는 가시광선영역에서 각각의 색을 구현하여 색채치료에 이용하기 위한 시스템을 개발하는데 있다. 사용된 광원은 에너지 밀도가 전파장에 걸쳐서 일정한 Dichroic reflector hallogen lamp를 사용하였고, 광원에서 발생하는 적외선을 차단하기 위하여 IR filter를 사용하였다. 색채치료에 사용 가능한 순수한 파장의 색을 분리하기 위하여 long pass filter와 short pass filter로 구성되는 color filter set를 사용하여 구성하였다. 개발된 가시광선 제시 시스템은 빨강, 파랑, 노란 광을 낼 수 있도록 되어 있으며 각각의 광도는 2390 lx, 1020 lx, 17400 lx이다. 개발된 시스템의 객관적 효과를 검증하기 위하여 피부 서식균으로 항균 실험을 하나 결과 노란 광이 빨강이나 파란 광에 비해 세포성장 억제가 컸다. 대식세포와 피부암세포로 실시한 항염 실험은 각각의 색광에 대한 영향이 크지 않았다.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.199-202
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• 2007

COMS (Communication, Ocean and Meteorological Satellite) is a geostationary satellite and has been developing by KARI for communication, ocean observation and meteorological observation. Conventional thermal control design, using MLI (Multi Layer Insulation), OSR (Optical Solar Reflector), heater and heat pipe, is utilized. Ka-band components are installed on South wall, while other equipment for sensors are installed on the opposite side, North wall. High dissipating communication units are located on external (surface) heat pipe and are covered by internal insulation blankets to decouple them from the rest of the satellite. External satellite walls are covered by MLI or OSR for insulation from space and for rejection internal heat to space. The ocean and meteorological sensors are installed on optical benches on the top floor to decouple thermally from the satellite. Single solar array wing is adopted in order to secure clear field of view of radiant cooler of IR meteorological sensor. This paper presents principles of thermal control design for the COMS.

• Journal of Integrative Natural Science
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• v.3 no.4
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• pp.237-240
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• 2010

Recently, number of studies for porous silicon have been investigated by many researchers. Multistructured porous silicon (PSi), distributed Bragg reflector (DBR) PSi, has been a topic of interest, because of its unique optical properties. DBR PSi were prepared by an electrochemical etch of $P^{{+}{+}}$-type silicon wafer of resistivity between 0.1 $m{\Omega}cm$ with square wave current density, resulting two different refractive indices. In this work, We have fabricated a simple and portable organic vapor-sensing device based on DBR porous silicon and investigated the optical characteristics of DBR porous silicon. DBR porous silicon have been characterized by FT-IR, Ocean optics 2000 spectrometer. The device used DBR PSi chip has been demonstrated as an excellent gas sensor, showing a great senstivity to a toxic vapor (TEP, DMMP, DEEP) at room temperature.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.128.2-128.2
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• 2011

스테인레스 스틸 유연기판 위에 플라즈마 화학기상 증착법 (plasma enhanced chemical vapor deposition)을 이용하여 nip 구조의 미세결정질 실리콘 박막 태양전지 (microcrystalline silicon thin film solar cell)를 제조하고 i ${\mu}c$-Si:H광 흡수층과 p ${\mu}c$-Si:H 사이에 i a-Si:H 버퍼 층을 삽입하여 i/p 계면특성을 개선하고 이에 따른 태양전지 성능특성 변화를 조사하였다. ${\mu}c$-Si:H 박막으로 이루어진 i/p 계면에서의 구조적, 전기적 결함은 태양전지 내에서 생성된 캐리어의 재결합과 shunt resistance 감소를 초래하여 개방전압 (open circuit voltage) 및 곡선 인자 (fill factor)를 감소시키는 것으로 알려졌다. 제조된 미세결정질 실리콘 박막 태양전지는 SUS/Ag/ZnO:Al/n ${\mu}c$-Si:H/i ${\mu}c$-Si:H/p ${\mu}c$-Si:H 구조로 제작되었으며 i/p 계면 사이의 i a-Si;H 버퍼층 두께를 변화시키고 이에 따른 태양전지의 특성을 조사하였다. 태양전지의 구조적, 전기적 특성 변화는 Scanning Electron Microscope (SEM), UV-visible-nIR spectrometry, Photo IV와 Dark IV를 통하여 조사하였다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.11
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• pp.1005-1009
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• 2008

A noble infrared $\lambda/4$ absorbing structure using metal reflector was studied for uncooled infrared sensors. This paper described the design and the fabrication of IR uncooled detectors which were composed of 21 by 21 elements using the surface micromachining technology. The characteristics of the array were investigated in the spectral region of 4.26 ${\mu}m$. The fabricated detectors exhibited the thermal mass of $9.75\times10^{-9}$ J/K, the thermal conductance of $1.31\times10^{-6}$ W/K, the thermal time constant of 7.4 ms, the responsivity of $1.07\times10^5$ V/W and the detectivity of $1.04\times10^9$ $cmHz^{1/2}/W$, at the chopper frequency of 10 Hz and the bias current of 9.22${\mu}A$. Finally the absorptance efficiency of $\lambda/4$ absorbing structure was about 23.2 % higher than that of absence absorbing structure.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.7
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• pp.138-143
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• 2016

The designed and fabricated millimeter-wave security screening system receives radiation energy from an object and a human body. The imaging system consist of sixteen array antennas, sixteen four-stage LNAs, sixteen detectors, an infrared camera, a CCD camera, reflector, and a focusing lens. This system requires high sensitivity and wide bandwidth to detect the input thermal noise. The LNA module of the system has been measured to have 65.8 dB in average linear gain and 82 GHz~102 GHz in bandwidth to enhance the sensitivity for thermal noise, and to receive it over a wide bandwidth. The detector is used for direct current (DC) output translation of millimeter-wave signals with a zero bias Schottky diode. The lens and front-end of the millimeter-wave sensor are important in the system to detect the input thermal noise signal. The frequency range in the receiving sensitivity of the detectors was 350 to 400 mV/mW at 0 dBm (1 mW) input power. The developed W-band imaging system is effective for detecting and identifying concealed objects such as metal or plastic.

• Korean Journal of Materials Research
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• v.18 no.12
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• pp.645-649
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• 2008

Graphite for the nuclear reactor is used to the moderator, reflector and supporter in which fuel rod inside of nuclear reactor. Recently, there are many researches has been performed on the various characteristics of nuclear graphite, however most of them are restricted to the structural and the mechanical properties. Therefore we focused on the thermal property of nuclear graphite. This study investigated the thermal emissivity following the oxidation degree of nuclear graphite with IG-11 used as a sample. IG-11 was oxidized to 6% and 11% in air at 5 l/min at $600^{\circ}C$. The porosity and thermal emissivity of the sample were measured using a mercury porosimeter and by an IR method, respectively. The thermal emissivity of an oxidized sample was measured at $100^{\circ}C$, $200^{\circ}C$, $300^{\circ}C$, $400^{\circ}C$ and $500^{\circ}C$. The porosity of the oxidized samples was found to increase as the oxidation degree increased. The thermal emissivity increased as the oxidation degree increased, and the thermal emissivity decreased as the measured temperature increased. It was confirmed that the thermal emissivity of oxidized IG-11 is correlated with the porosity of the sample.