• Aerospace Engineering and Technology
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• v.7 no.1
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• pp.115-120
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• 2008

The thermistors and AD590 are widely used for temperature measurement in space application. The resistance of thermistor will vary according to the temperature variation therefore the external voltage or current stimulus signal have to be provided to measure resistance variation. Recently high resolution electro optic camera system of satellite requires tight thermal control of the camera structure to minimize the thermal structural distortion which can affects the image quality. In order to achieve $1^{\circ}$(deg C) thermal control requirement, the accuracy of temperature measurement have to be higher than $0.3^{\circ}$(deg C). In this paper, the accuracy of temperature measurement using thermistors is estimated and analyzed.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.3
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• pp.360-366
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• 2018

In shipyards hull forming is performed by the line heating method using a gas torch and by cold treatment using a roll-press. However, this forming process has some issues, such as difficulties in controlling and accurately estimating the amount of the heat input, as well as a harsh working environment due to exposure to loud noises and air pollution. The induction heating method, which is introduced in this paper, exhibits good control and allows for the estimation of precise heat input. Also, workers can carry out the induction heating in a comfortable working environment. In this research, the induction heating simulation, which consists of electro-magnetic, heat transfer and thermal elasto-plastic analysis, was developed and modified through induction heating experiments. Finally, the effective heating coil was designed for the automatic hull forming system based on the results of induction heating simulation. For the purposes of a future study, if an algorithm to obtain optimal working conditions is developed, automatic systems for hull forming can then be constructed.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.153-153
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• 2015

Application of the plasma is already highlighted as a new technology in the last few years. In these days, there are lots of attempt in various application with plasma in that it is known as an effective treatment to animal, plants, material and so on. Plasma in liquid, one of new plasma applications, has advantages in ability to treat bio-cell or solutions. For example, electro-surgery, water purification, radical generation and so on. Especially, plasma discharge in solutions is very useful technique and difficult to generate due to electrolysis, vaporization and something else. In this study, we have performed plasma discharge and checked sustainability of plasma in solution(saline 0.9%). And we have measured basic characteristics of plasma in liquid. Such as electrical energy and plasma density are calculated from discharging current and voltage. Also, its thermal energy is measured with IR camera.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.1225-1228
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• 2004

We have studied the Polymer Stabilized Continuous Director Rotation (PSCDR) mode to solve the thermal shock problem which is core and main problem in CDR mode. The cell filled 95wt. % R2301 FLC and 5wt. % UCL-001 polymer is applied a low DC voltage only near the phase transition temperature from cholesteric to chiral smectic C phase transition to get defect-free alignment. In the previous work, we also confirmed layer deformation induced by an applied DC field only near the phase transition temperature from Ch to $SmC^{\ast}$. Results of layer structure, and characteristics of electro-optical properties between CDR and PSCDR mode will be discussed in this paper. We are also in progress to finalize the layer structures compared between CDR and PSCDR mode by x-ray measurements.

• Proceedings of the Korean Vacuum Society Conference
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• 2007.02a
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• pp.122-122
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• 2007

• Textile Coloration and Finishing
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• v.17 no.1
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• pp.45-51
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• 2005

Soluble keratose(S-keratose) could be obtained by oxidizing the wool keratin with performic acid. S-keratose/PVA solutions were made by dissolving them in the formic acid and S-keratose/PVA web of sub-micron size was made by electro-spinning technique. SEM, elemental analysis, FT-IR, X-ray diffractometry, and TGA were used to characterize the properties of S-keratose/PVA solutions and fibers. As the S-keratose content in S-keratose/PVA solution increased, viscosity of solution decreased while electrical conductivity has increased. The fiber diameter has decreased with increasing the S-keratose content. S-keratose/PVA ratio in fibers were similar to the ratio in the solutions. The crystalline structures of S-keratose and PVA existed separately in the electrospun webs. Thermal stability of the web increased with the PVA content increasing.

• Textile Coloration and Finishing
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• v.17 no.1
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• pp.38-44
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• 2005

Oxidation method was used to extract S-keratose from wool. Wool was treated with performic acid and soluble fraction(S-keratose) was collected by evaporating the solvent. S-keratose and Nylon 6 were dissolved in formic acid at the ratio of 100/0, 80/20, 50/50, 20/80, and 0/100, and S-keratose/Nylon 6 web of sub-micron size was made by electro-spinning technique. SEM, EA, FT-IR, XRD, and TGA were used to characterize the properties of S-keratose/Nylon 6 solutions and electrospun fibers. As the Nylon 6 content increased, viscosity, conductivity of the electrospinning solution and the diameter of spun fiber increased. Electrospun nonwoven webs have the same S-keratose/Nylon 6 ratios of the spinning solutions. The crystalline structures of S-keratose and Nylon 6 existed separately in the electrospun webs. Thermal stability of the webs increased due to Nylon 6 content.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.106-106
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• 2003

반도체 소자의 고집적화에 따라 채널길이와 배선선 폭은 점차 줄어들고, 이에 따라 단채널효과, 소스/드레인에서의 기생저항 증가 및 게이트에서의 RC 시간지연 증가 등의 문제가 야기되었다. 이를 해결하기 위하여 자기정렬 실리사이드화(SADS) 공정을 통해 TiSi2, CoSi2 같은 금속 실리사이드를 접촉 및 게이트 전극으로 사용하려는 노력이 진행되고 있다. 그런데 TiSi2는 면저항의 선폭의존성 때문에, 그리고 CoSi2는 실리사이드 형성시 과도한 Si소모로 인해 차세대 MOSFET소자에 적용하기에는 한계가 있다. 반면, NiSi는 이러한 문제점을 나타내지 않고 저온 공정이 가능한 재료이다. 그러나, NiSi는 실리사이드 형성시 NiSi/Si 계면의 산화와 거침성(roughness) 때문에 높은 누설 전류와 면저항값, 그리고 열적 불안정성을 나타낸다. 한편, 초고집적 소자의 배선재료로는 비저항이 낮고 electro- 및 stress-migration에 대한 저항성이 높은 Cu가 사용될 전망이다. 그러나, Cu는 Si, SiO2, 실리사이드로 확산·반응하여 소자의 열적, 전기적, 기계적 특성을 저하시킨다. 따라서 Cu를 배선재료로 사용하기 위해서는 확산방지막이 필요하며, 확산방지재료로는 Ti, TiN, Ta, TaN 등이 많이 연구되고 있다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.762-765
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• 2003

에틸렌글리콜(ethyleneglycol)을 이용한 폴리비닐에테르(polyvinyl ether)와 같은 고분자물질을 활용하여 Co$^{30}$ 방사선원으로부터 ${\gamma}$선을 조사시켜, 고분자 물질의 성질을 변화시킴으로써 화학, 전기전자, 환경 및 기타 여러 가지 응용분야에 적용하여 이용할 수 있는 기술을 개발하였다. 이를 바탕으로 관련재료의 단량체(monomer)로부터 중합체(polymer)를 합성하여 water swelling을 시키는 과정에서 각종 (금속) 이온을 흡입-제거하는 방법의 환경복원기술, 흡입 금속이온을 표면에 밀집시켜 금속막을 형성하는 응용기술, 생체조직의 대용물질로 활용하는 의용공학 및 열감지특성(thermal sensitive property) 또는 pH 감지특성(pH sensitive property)을 이용하여 의용기술에 적용하는 polymer 응용기술 등의 폭넓은 활용을 위하여 그 일환으로 전도성 고분자 제조기술로의 활용가능성을 연구하였다.

• Proceedings of the KIPE Conference
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• 2012.11a
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• pp.7-8
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• 2012

본 논문에서는 3레벨 NPC(Neutral Point Clamped)와 Active NPC 인버터의 스위치 손실 분배 기법에 따른 출력전력 분석을 하였다. 기존 3레벨 NPC 인버터의 경우 특정 불균형한 스위치 발열 때문에 전력밀도를 높이 설계할 수 없다. 따라서 본 논문에서는 ANPC inverter의 손실 분배기법을 적용하여 시뮬레이션으로 검증하였다.