• Proceedings of the KAIS Fall Conference
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• 2007.11a
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• pp.133-135
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• 2007

PMMA (polymethyl metha crylate) 유기막의 농도별 최적화를 위하여 1, 2, 4, 6, 8 wt.%의 PMMA 농도별로 Al/PMMA/ITO/Glass 구조의 MIM (metal- insulator-metal) 캐패시터 소자를 제작하였다. 유기 절연층의 형성은 ITO/Glass 기판 위에 PMMA를 용질로, Anisle을 용매로 사용하여 스핀코팅법으로 소자를 형성하였다. 제작된 소자에 대해 농도에 따른 전기적 특성을 조사한 결과 누설전류는 2wt.% 농도의 PMMA로 제작된 소자에서 0.3 pA로 가장 우수한 결과를 얻을 수 있었다. 또한 동일한 PMMA 농도로 제작된 캐패시터 소자의 정전용량은 1.2 nF으로 가장 좋은 결과를 얻을 수 있었으며, 계산된 값과 매우 유사한 값을 얻을 수 있었다.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2007.04a
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• pp.31-35
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• 2007

RFID is going to be the core technology for contact-less information transfer means in the era of ubiquitous. Up until recent days, the RFID didn't fit to be used in outdoor environment due to the fact that it was developed for logistics which does not require stability in outdoor. But recently, requests for the RFID to be used in the outdoor environment have increased, and this laid the foundation for the development of outdoor tags, including MetalTag, which can be utilized in many different ways. In this research, to provide information on the control point using the RFID at the sight, RFID tags, which can place at the control point, and PDA based system were developed.

• Bulletin of the Korean Chemical Society
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• v.35 no.9
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• pp.2665-2668
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• 2014

Aptamers are oligonucleotides or peptide molecules that are able to bind to their specific target molecules with high affinity via molecular recognition. In this study, we present development of aptamer-based precipitation assays (or simply aptamoprecipitation) for His-tagged proteins and thrombin to compare their purification efficiency with other conventional affinity precipitation methods. A crosslinking method was employed to immobilize thiol-functionalized aptamers onto the surface of polystyrene resins, enabling them to specifically bind to His-tag and to thrombin, respectively. The resulting aptamer-functionalized resins were successfully applied via a one-step experiment to purification of His-tagged proteins from complex E. coli and to thrombin extraction, exhibiting superior or at least comparable purification results to the conventional immobilized metal affinity precipitation or immunoprecipitation.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.5
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• pp.322-327
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• 2014

Internal corrosion of the distribution line can be detected in order to develop techniques of non-destructive inspection methods that operate only on the metal track eddy current diagnosis is possible by applying the technique investigated. Sensor for the production of a finite element method modeled by using an eddy current sensor, a distribution line by using an accelerated aging samples of sodium hydroxide was prepared. Sheathed cables for internal corrosion studies detected using an eddy current sensor is considered to be possible.

• Journal of Electrical Engineering and Technology
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• v.7 no.3
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• pp.401-405
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• 2012

Current research about voltage leakage involves investigation of the effects of leaked voltage and current on humans through simulated environments and dummies. Electrocution results from leaked current when electricity flows through the body as a result of potential difference. Research that analyzes actual electrocution is insufficient because of the danger from leaked voltage present in the leakage area. This thesis analyzes magnetic flux density from current around a leak to investigate the distribution of current. The authors used a simulated environment to investigate electrocution accidents that frequently occur during floods through leakage along metal surfaces, and evaluated the distribution of leaked magnetic flux.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.45 no.5
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• pp.201-208
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• 2008

An active RFID system has the advantages of a long identification distance and a good identification rate as well as overcoming the passive RFID's drawback such as the lowering of identification rate on metal materials. So, the development of an active RFID system has been gradually increasing in harbor logistics and the national defense area. On the other hand, some identification failures between products developed under the same standards have been reported, and there are difficulties in evaluating the interoperability between developed Products and standard conformance test because an accurate evaluation method and equipment has not been established at the international level. Motivated by these, this study presents a realization of the hardware and software of emulator to evaluate the standard conformance of an active RFID system, Performance of the designed system are then analyzed by means of simulations of Matlab/Simulink, and the applicability of the emulator is verified by evaluating the standard conformance of a real active RFID tag.

• Applied Chemistry for Engineering
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• v.16 no.2
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• pp.250-256
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• 2005

Coating appearance is the most important problem in automotive industry. To increase the coating appearance quality, the corrosion resistance and the coating adhesion on metal substrates must be basically solved. The phosphating film made by the pretreatment of metal substrate is important factor to increase the coating adhesion. During the cathodic electrodeposition, the pH at the cathode surface increases up to about 12. In such a highly alkaline condition, the dissolution of metal substrate and phosphate film occurs. These phenomena result in the decrease of the bonding strength between the phosphating film and the substrate. Generally, the structure of zinc phosphating film is hopeite or phosphophyllite. It has been known that the phosphophyllite film contains better corrosion resistance and paint adhesion for hot water immersion test because of the decrease of dissolving amount of both metal substrate and phosphating film during the cathodic electrodeposition. It is found that the addition of Ni and Mn composition increase P-ratio and then can improve the paint adhesion on metal surface and the corrosion resistance.

• Journal of the Semiconductor & Display Technology
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• v.6 no.4
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• pp.69-73
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• 2007

The MIM(metal-insulator-metal) capacitors with the Al/PMMA/ITO/Glass structures were manufactured according to various PMMA concentration of 1, 2, 4, 6, 8 wt%. The lowest leakage current and the largest capacitance were found to be 2.3 pA and 1.2 nF, respectively, for the device with 2 wt% PMMA concentration. The measured capacitance of the devices was almost same values with the calculated one. The optimum film thickness was obtained at the value of 48 nm, showing that the capacitance and leakage current were 1.92 nF, 0.3 pA at 2 wt%, respectively. From this experiment, the PMMA gate insulator films can be applicable to the organic thin film transistors.

• Journal of Powder Materials
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• v.19 no.6
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• pp.446-450
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• 2012

In order to fabricate the porous Mo with controlled pore characteristics, unique processing by using $MoO_3$ powder as the source and camphene as the sublimable material is introduced. Camphene-based 15 vol% $MoO_3$ slurries, prepared by milling at $50^{\circ}C$ with a small amount of dispersant, were frozen at $-25^{\circ}C$. Pores were generated subsequently by sublimation of the camphene during drying in air for 48 h. The green body was hydrogen-reduced at $750^{\circ}C$, and sintered at $1000-1100^{\circ}C$ for 1 h. After heat treatment in hydrogen atmosphere, $MoO_3$ powders were completely converted to metallic W without any reaction phases. The sintered samples showed large pores with the size of about $150{\mu}m$ which were aligned parallel to the camphene growth direction. Also, the internal wall of large pores and near bottom part of specimen had relatively small pores due to the difference in the camphene growth rate during freezing process. The size of small pores was decreased with increase in sintering temperature, while that of large pores was unchanged. The results are strongly suggested that the porous metal with required pore characteristics can be successfully fabricated by freeze-drying process using metal oxide powders.

• Korean Journal of Materials Research
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• v.21 no.9
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• pp.520-524
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• 2011

Porous W with controlled pore characteristics was fabricated by a freeze-drying process. $WO_3$ powder and camphene were used as the source materials of W and sublimable vehicles, respectively. Camphene slurries with $WO_3$ contents of 10 and 15 vol% were prepared by milling at $50^{\circ}C$ with a small amount of oligomeric polyester dispersant. Freezing of a slurry was done in a Teflon cylinder attached to a copper bottom plate cooled at $-25^{\circ}C$ while the growth direction of the camphene was unidirectionally controlled. Pores were generated subsequently by sublimation of the camphene during drying in air for 48 h. The green body was hydrogen-reduced at $800^{\circ}C$ for 30 min and sintered in a furnace at $900^{\circ}C$ for 1 h under a hydrogen atmosphere. Microstructural observation revealed that all of the sintered samples were composed of only W phase and showed large pores which were aligned parallel to the camphene growth direction. The porosity and pore size increased with increasing camphene content. The difference in the pore characteristics depending on the slurry concentration may be explained by the degree of powder rearrangement in the slurry. The results strongly suggest that a porous metal with the required pore characteristics can be successfully fabricated by a freeze-drying process using metal oxide powders.