• Fire Science and Engineering
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• v.24 no.5
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• pp.94-101
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• 2010

The pipes using in water-based fire protection systems are used steel pipes for ordinary piping, carbon steel pipes for pressure service, copper and copper alloy seamless pipes and tubes, etc. By last buildings of high-rising, complexity, in fire protection systems, the corrosion resistance, easy construction, lightweight and cost-effective use of the pipes is being considered. Among the pipes, the possibility of used for fire protection system being used in the existing copper pipe of material properties, strength, corrosion resistance, heat resistance through and compare the performance was evaluated. As a result of that assessment light gauge stainless steel pipes for ordinary piping (KS D 3595) at a water pressure of less than 1.2 MPa can be used in sufficient physical properties, strength, corrosion resistance, heat resistance and have been observed.

• Fire Science and Engineering
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• v.32 no.1
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• pp.40-45
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• 2018

It is considered that vermiculite as an inorganic material is highly effective when it is used as a building finishing material because it is eco-friendly. Vermiculite has excellent properties such as fire resistance, heat insulation, sound absorption as well as prevention of condensation, deodorization and aesthetics. In this study, we developed a finishing board with vermiculite as its main material and mixed with mineral loose wool (VB-L) or mineral powder (VB-P), and conducted fireproof test and insulation test. In addition, fire resistance tests were carried out by applying the two developed vermiculite boards as finishing materials for the standard wall details of light frame wood structures (KS F 1611-1). As a result of the fire resistance test, the VB-L specimen showed better fire resistance than the VB-P specimen. Both vermiculite boards showed sufficient fire resistance performance of 2 hours for a thickness of 30 mm.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.446-449
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• 2008

Organic light emitting diodes (OLEDs) with multiple organic layers were fabricated to obtain and to evaluate an equivalent resistance and an equivalent capacitance of OLED device. The staircase voltage with an increasing period and a constant period was designed and applied to the OLED. The resistance of OLED was found to decrease from $270\;k{\Omega}$ to $2\;K{\Omega}$ as applied voltage increased after turn on. The equivalent capacitance of OLED maintained unchanged at low voltage level and deceased after showing peak value as the applied voltage increased.

• Journal of the Semiconductor & Display Technology
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• v.10 no.4
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• pp.43-46
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• 2011

In this study, we investigated the effects of the post Ar plasma treatment at different RF powers for various durations on electrical, structural, and optical properties of relatively thin Al-doped zinc oxide films. The sheet resistance was observed to decrease rapidly for the first 5min, beyond which the resistance apparently saturated. As the RF power increased, the grain size and the interplanar distance of (002) planes also increased. The observed decrease in sheet resistance was stated to be a consequence of Al and/or Zn interstitials as well as grain growth. It was also found that Ar plasma treatment increased the transmittance of Al-doped zinc oxide films in most of the visible light range below the blue light.

• Journal of the Korean Institute of Telematics and Electronics
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• v.24 no.6
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• pp.980-985
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• 1987

The thin metal films of Cr, Al, Mn and were made in various evaporation rates with 100\ulcornerthickness under 2x10**-9 bar vacuum level. We analized and discussed the relationships between changes of structure, morphology and sheet resistance, light transmittance for the corresponding evaporation rates. As the evaporation rates were decreased at higher rates, grain sizes of all film were decreased, however both of the sheet resistance and light transmittance were increased. At lower evaporation rate, films of Cr and Cu porduced non-stoi-chiometric oxides but Al an Mn showed up amorphous structures.

• Fire Science and Engineering
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• v.25 no.4
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• pp.22-27
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• 2011

Fire resistance ceiling system is the structure of which the ceiling installed under the slave of the structure has the fire resistance performance. Because of having the fire resistance performance, fire resistive coatings on steel beams can be reduced and large span structures can be constructed. So, it have advantages of convenience for construction, shorten for construction time and cost reducing. In foreign country, it is general that one system consisting of slave and ceiling is constructed as a fire resistance system. But in Korea, there are no fire resistance ceiling systems thus economical efficiency due to being high-rise and light-weight of structures is not secured. Therefore research and development of nominal fire resistance ceiling systems is necessary. On this study, fire resistances of standard non-loadbearing ceiling systems were assessed and basic informations for developing the fire resistance non-loadbearing ceiling systems were presented.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.4
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• pp.363-367
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• 2015

This paper reports on thermally adjusted graphene oxide (GO) as the hole transport layer (HTL) for organic light-emitting diodes (OLEDs). GO is generally not suitable for HTL of OLEDs because of intrinsic specific resistance. In this paper, the specific resistance of GO is adjusted by the thermal annealing process. The optimum specific resistance of HTL is found to be $10^2{\Omega}{\cdot}m$, and is defined by the maximum current efficiency of OLEDs, 2 cd/A. In addition, the reasons for specific resistance change are identified by x-ray photoelectron spectroscopy (XPS). First, the XPS results show that several functional groups of GO were detached by thermal energy, and the amount of epoxide changed substantially following the temperature. Second, the full width at half maximum (FWHM) of the C-C bond decreased during the process. That means the crystallinity of the graphene improved, which is the scientific basis for the change in specific resistance.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.3
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• pp.234-238
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• 2014

Multichip packaging was achieved the best solution to significantly reduce thermal resistance at the same time, to increase luminance intensity in LEDs packaging application. For the packaging, thermal spreading resistance is an important parameter to get influence the total thermal performance of LEDs. In this study, silicon-based multichip light emitting diodes (LEDs) packaged module has been examined for thermal characteristics in several parameters. Compared to the general conventional single LED packaged chip module, multichip LED packaged module has many advantages of low cost, low density, small size, and low thermal resistance. This analyzed module is comprised of multichip LED array, which consists of 32 LED packaged chips with supplement power of 0.2 W at every single chip. To realize the extent of thermal distribution, the computer-aided design model of 6.4 W Si-based multichip LED module was designed and was performed by the simulation basis of actual fabrication flow. The impact of thermal distribution is analyzed in alternative ways both optimizing numbers of fins and the thickness of that heatsink. In addition, a thermal resistance model was designed and derived from analytical theory. The optimum simulation results satisfies the expectations of the design goal and the measurement of IR camera results. tart after striking space key 2 times.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.05b
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• pp.57-60
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• 2004

Electrical arc is the final stage of insulation breakdown and has high current density which cause heat and light in insulator. Insulator under electrical arc lost its insulating strength and eternal damages. Conventional criterion of electrical arc resistance in Standards have depended on the change of sound pressure and light color after damages on insulator by electrical arc. The recognition of these changes is done by human himself which was very subjective and resulted in some error to judge whether insulator has damages or not. This paper has shown that antenna method is the appropriate measure to judge electrical arc resistance for insulator. Antenna measures the electromagnetic waves radiated from tungsten electrodes with 6mm gap regulated by KSC2130. Applied voltage cross two tungsten electrodes have two different methods such as 1/8 10 and continuous 10mA. Signal amplitudes obtained by antenna has diminished after the damage of insulator, which will provide objective and good way to judge the electrical arc resistance.

• The Korean Journal of Food And Nutrition
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• v.11 no.5
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• pp.506-512
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• 1998

In order to replance systhetic colors by natural colors as food additive, properties of Gardenia yellow color and Gardenia blue color were compared with Food yellow No. 4 and Food blue No. 1. Color differeance between Food yellow No. 4 and Gardenia yellow color was 7.55. Thermal stability of Food yellow No. 4 was above 99%. On the other hand, in case of Gardenia yellow color, showed adove 90% of residual color units in 8$0^{\circ}C$$\times$30min and 10$0^{\circ}C$$\times$30min at pH 7.0 but 75% in 121$^{\circ}C$$\times$15min. Difference of light stability between Food yellow No. 4 and gardenia yellow color was about 18%. Addition of ascorbic acid was increased about 6% in light stability. Color difference between Food blue No. 2 and Gardenia blue color was 107. Thermal stability of Food blue No. 2 was above 99%. But Gardenia blue color showed 92% of residual color units in 8$0^{\circ}C$$\times$30min and 10$0^{\circ}C$$\times$30min at pH 7.0 but 90% in 121$^{\circ}C$$\times$15min. Difference of light stability between Food blue No. 4 and Gardenia blue color was about 8%. Addition of -tocopherol was increased about 4% in light stability of Gardenia blue color.