• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.4
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• pp.140-146
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• 2017

As energy conservation and environmental issues are emerging as a hot topic around the world, consumers are demanding high-efficiency, eco-friendly products. In this study, the author proposed 120W LED lighting system that replace metal halide lamp (MHL) which is currently used in the industry. Furthermore, it would be possible to provide a perfect opportunity for Korea to rise as a global leader in the LED lighting industry through soundness evaluation of the LED lighting system that is applied.

• The Journal of the Korea Contents Association
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• v.16 no.11
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• pp.693-698
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• 2016

Bruise caused by damages through physical compression and suction is one of evidences that can prove abuse or assault. It is essential for taking photography to prove a crime. Some studies about the Infrared (IR) light source have limitations that only one IR light source and one barrier filter were used. To find the best combination of filters and IR light sources, we produced suction bruise artificially and used three IR light sources and five barrier filters. Consequently, we found that the best combination is using a tungsten lamp and Kodak Wratten #18A barrier filter.

• Transactions of Materials Processing
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• v.27 no.2
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• pp.87-92
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• 2018

Auto industries have tried to employ lightweight alloys to improve the fuel efficiency of manufactured vehicles, as the environmental concern becomes an important issue. Even though the aluminum alloy is one of the most appropriate lightweight alloys for auto parts, the low formability of an aluminum alloy has been an obstacle to its application. In order to resolve the low formability problem, a recent study (Lee et al., 2017 [1]) showed that the infrared (IR) local heat treatment can improve the formability with a reduction of heating energy. However, the aforementioned study was limited to only a linear line heating. Since many of the available auto parts as applicable to vehicle manufacturing have a curved line shape, the heating experiments for a curved line should be studied. The possibility of building IR lamps having complex shapes is an advantage of the IR lamp, since it can control the heating shape. This work conducted the IR local heat treatment for the curved line. The experimental results show that the IR local heat treatment can improve the formability of the aluminum alloy for curved line. Additionally, it is shown that the IR local heat treatment also reduces the heating energy when it is compared with the furnace heating which heats a blank as a whole. A numerical simulation with a stress-based forming limit diagram also supports the experimental results.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.57 no.4
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• pp.404-407
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• 2008

Because of directly receiving the thing in which a microwave is reflected and comparing the frequency, the microwave sensor with doppler effect completely overcomes the problem of the passive infrared sensor. The microwave sensor with doppler effect well operates about a temperature, the dust, and the peripheral noise because of being dull in the most of ambient conditions. The system developed in this research is the electricity saving detection sensor which it senses the real time action of a man as the microwave sensor and automatically turns on the electric lamp and turns off, minimizes the electrical energy consumption. Since the microwave sensor is not influenced in the light, the dust, and the natural element like the ambient temperature, the effectiveness is considered to be superior to the passive infrared sensor being used currently. There was the energy reduction effect more than about 60% in the performed example which established this system. When this was compared with the construction cost, the cost of establishing payback period was about 1-1.5 year. The microwave sensor with doppler effect developed from this research result is convinced in the future to do enough for the electric energy saving.

• Journal of Microbiology and Biotechnology
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• v.21 no.12
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• pp.1306-1311
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• 2011

Recombinant Rhodopseudomonas palustris, harboring the carotenoid-metabolizing gene crtI (CrtIBS), and whose color changes from greenish yellow to red in response to inorganic As(III), was cultured in transparent microplate wells illuminated with a light emitting diode (LED) array. The cells were seen to grow better under near-infrared light, when compared with cells illuminated with blue or green LEDs. The absorbance ratio of 525 to 425 nm after cultivation for 24 h, which reflects red carotenoid accumulation, increased with an increase in As(III) concentrations. The detection limit of cultures illuminated with near-infrared LED was 5 ${\mu}g$/l, which was equivalent to that of cultures in test tubes illuminated with an incandescent lamp. A near-infrared LED array, in combination with a microplate, enabled the simultaneous handling of multiple cultures, including CrtIBS and a control strain, for normalization by the illumination of those with equal photon flux densities. Thus, the introduction of a near-infrared LED array to the assay is advantageous for the monitoring of arsenic in natural water samples that may contain a number of unknown factors and, therefore, need normalization of the reporter event.

• Journal of Applied Reliability
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• v.18 no.1
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• pp.87-94
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• 2018

Purpose: In this study, the defect quantification of thin metal plate was evaluated by using lock-in infrared thermography. Methods: A STS304 standard specimens, which had the artificial-defects of different size, were used. The focal distance between the infrared camera and the specimen was set to 500mm, and the distance between the lump and the specimen was set to 200mm. One halogen lamp with a maximum capacity of 1kW was used, and phase-lock infrared thermal images with a frequency of 1Hz were captured and analyzed. Result: Objectively quantified data values were obtained by analyzing the contrast ratio and signal-to-noise ratio. Conclusion: The possibility of defect diagnosis for thin metal plate was confirmed by using the lock-in infrared thermography technique.

• Journal of the Korean Institute of Gas
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• v.15 no.4
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• pp.51-55
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• 2011

This paper describes the temperature compensation algorithm using thermopile detector for nondispersive infrared methane gas sensor. From the output voltage of thermistor that is attached onto the infrared detector, the ambient temperature was extracted. The effects of temperatures on the properties of sensor module (the characteristics of narrow bandpass filter, optical cavity and infrared lamp, and gas absorption coefficient times optical path length) have been introduced in order to implement the temperature compensation algorithm. Even though the measurement error of developed sensor module was in the range of $\pm$ 1,500 ppm, after programming the temperature compensation algorithm, the developed sensor module shows a high accuracy less than +180 ppm error within $20^{\circ}C$ temperature variation.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.1
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• pp.41.1-41.1
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• 2010

IGRINS (the Immersion GRating Infrared Spectrograph) is a high resolution infrared spectrograph which is being developed by a collaboration of the University of Texas, the Korea Astronomy and Space Science Institute, and Kyung Hee University. The wavelength calibration unit of IGRINS will be situated between the telescope flange and IGRINS dewar. It will include Th-Ar hallow cathode lamp, optical elements, and gas absorption cell for the case that requires precise calibration (e.g., radial velocity observation). The system will also use a tungsten halogen lamp in an integrating sphere as a blackbody source for the flat-field imaging. IGRINS will be placed initially on the McDonald 2.7m Harlan J. Smith telescope and later on 4-8m class telescopes. We present an overview of the plan for the wavelength calibration sources and of the development process for the optical and mechanical design of the IGRINS calibration system.

• Current Photovoltaic Research
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• v.5 no.3
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• pp.83-88
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• 2017

The growth of intermetallic compounds is an important factor in the reliability of solar cells. Especially, the temperature change in the soldering process greatly affects the thickness of the intermetallic compound layer. In this study, we investigated the intermetallic compound growth by Sn-diffusion in solder joints of solar cells. The thickness of the intermetallic compound layer was analyzed by IR lamp power and hot plate temperature control, and the correlation between the intermetallic compound layer and the adhesive strength was confirmed by a $90^{\circ}$ peel test. In order to investigate the growth of the intermetallic compound layer during isothermal aging, the growth of the intermetallic compound layer was analyzed at $85^{\circ}C$ and 85% for 500 h. In addition, the activation energy of Sn was calculated. The diffusion coefficient of the intermetallic compound layer was simulated and compared with experimental results to predict the long-term reliability.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.155.2-155.2
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• 2011

We present development of the calibration system for IGRINS (the Immersion GRating Infrared Spectrograph). We mainly use Th-Ar and U hollow cathode lamp as the spectral calibration source and telluric features can be used additionally. For the flat source, we selected a 3000K tungsten halogen lamp with 2 inch integrating sphere. From Light Tools simulation, the result flat image through calibration optics satisfied <1% flatness error requirement. We also present mechanical design of calibration box that will be attached on the IGRINS dewar. Three moving stages are designed to perform switching mechanism between all of the observing modes - target observation, flat, precision RV measurement, and spectro-polarimetric observation.