• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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• pp.57-58
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• 2005

The properties such as capacitance and resonant frequency are important in embedded capacitors. Accurate equivalent model is required to find these properties of embedded capacitor. In this paper, we investigate to analyze the properties of high-K embedded capacitor which was fabricated by Low Temperature Co-fired Ceramic (LTCC). Modeling based on partial element equivalent circuit (PEEC) method is performed using HSPICE circuit simulation. This modeling methodology can provide the good inspection of embedded capacitor to device engineer.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 춘계학술발표강연 및 논문개요집
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• pp.131-131
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• 2003

Surface micromachined uncooled IR detector with the optimized VOx bolometric layer was fabricated based on sandwich structure of the V$_2$O$_{5}$V/V$_2$O$_{5}$. In order to improve the detectivity of the IR detector, we optimized a few factors in the viewpoint of bolometric material. Vanadium oxide thin film is a promising material for uncooled microbolometers due to its high temperature coefficient of resistance at room temperature. It is, however, very difficult to deposit vanadium oxide thin films having high temperature coefficient of resistance and low resistance because of process limits in microbolometer fabrication. In order to increase the responsivity and decrease noise, we increase TCR of bolometric material and decrease room temperature resistance based on the sandwich structure of the V$_2$O$_{5}$V/V$_2$O$_{5}$ by conventional sputter. By oxygen diffusion through low temperature annealing of V$_2$O$_{5}$V/V$_2$O$_{5}$ in oxygen ambient, various mixed phase vanadium oxide was formed and we obtained TCR in range of-1.2 ~-2.6%/$^{\circ}C$ at room temperature resistance of 5~100k$\Omega$.mega$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.248-248
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• 2007

Demands for electricity are growing, whereas the rate of electricity infrastructure's construction declines gradually. To keep the balance of the demand and supply, the share of underground transmission line will be increased from 8.3% to 10.5% in 2020 but it will be accompanied with enormous public expenses. A great concern in high capacity transmission is on the increase so as to maximize the spacial efficiency. High Temperature Superconducting (HTS) cable is in the lime light which has the merits of environment-friendly, low transmission loss and high transmission with low voltage, but the reliability verification as a power system is yet to be solved. KEPCO completed the installation and acceptance of $3{\phi}$, 22.9kV, 1250A class HTS cable system in 2006 and the long term test is in progress. The test results focusing on long term reliability are presented in this paper.

• 한국의류학회지
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• 제16권3호
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• pp.251-256
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• 1992

As a basic expriment to find out the thermal insulation effect of bedding KES-F7 was used to measure. The warmth retaining ratio of the six kinds of filling materials as cotton, wool , silk, down, cotton/polyester was measured, and the infleunce on the warmth retaining ratio of the warmth retaining ratio and humidity by the material was investigated. The results obtained are as follows: 1. The warmth retaining ratio of each filling material was shown to range from $70\%$ to $77\%$ . The warmth retaining ratio of each material preyed to be high in order down> polyester> cotton/polyester>cotton>silk>wool fiber. 2. The warmth retaining ratio of each filling material decreased with the inclose of the humidity The effective reduction rate by filling fiber's was high in order wool>cotton>cotton/polyester>silk>down>polyester material. 3. The warmth retaining ratio of each filling material was shown to be in counter-correlation with the humidity, and the correlation coefficient (r=0.94-0.98) proved to be highly signi-ficant.

• 한국해양공학회지
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• 제29권3호
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• pp.241-248
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• 2015

A subsea pipeline for oil/gas transportation or gas injection is subjected to extreme variations in internal pressure and temperature, which can involve a strain rate effect on the pipeline material. This paper describes the flow stress characteristics of a pipeline material called API 5L X52N PSL2, using and experimental approach. High-speed tensile tests were carried out for two metal samples taken from the base and weld parts. The target temperature was 100℃, but two other temperature levels of –20℃and 0℃ were taken into account. Three strain rates were also considered for each temperature level: quasi static, 1/s, and 10/s. Flow stress data were proposed for each temperature level according to these strain rates. The dynamic hardening behaviors of the base and weld metals appeared to be nonlinear on the log-scale strain rate axis. A very high material constant value was required for the Cowper-Symonds constitutive equation to support the experimental results.

• 한국지반신소재학회논문집
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• 제16권4호
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• pp.13-20
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• 2017

본 연구에서는 순환 유동층 보일러의 고칼슘 연소재를 활용하여 개발한 새로운 매입말뚝의 주면고정액(ZA-Soil)에 대한 성능을 평가하기 위해 실내시험을 실시하였고, 보통 포틀랜드시멘트와의 비교평가를 실시하였다. 실내시험 결과, 매입말뚝의 고강도 주면고정액(ZA-Soil 1)과 저강도 주면고정액(ZA-Soil 2)의 압축강도는 보통 포틀랜드시멘트 대비 68.0%와 64.6%인 것으로 나타났고, 적절한 유동성과 환경적 안정성을 확보하고 있는 것으로 나타났다. 또한 매입말뚝의 고강도 주면고정액(ZA-Soil 1)을 흙 재료와 혼합한 경우 재령 28일에서의 압축강도가 보통 포틀랜드시멘트를 사용한 경우의 압축강도에 비해 1.10~1.23배 큰 것으로 나타나 강도증진효과가 우수한 것으로 나타났다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.414-415
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• 2006

At present, Characteristic of high color reproduction for LCD products needed in Display market. Therefore, The improving methods of high color reproduction are alteration of color Filter or Red, Green, Blue phosphor alteration of CCFL. But High color reproduction phosphor is short life time as compared with conventional phosphor. In this experiment, by using split the Red, Green, Blue CCFL with high color reproduction phosphor instead of conventional high color reproduction CCFL. We knew that the high color reproduction RGB split CCFL BLU has same spectrum data and chromaticity, but has long life time as manufacturing RGB split CCFL and reduce chromaticity shift following long time discharge as compared with conventional high color reproduction CCFL.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2003년도 춘계학술대회 논문집
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• pp.313-318
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• 2003

The development of new materials with light weight and high strength has become vital to the machinery, aircraft and auto industries. However, there are a lot of problems with developing such materials that require expensive tools, and a great deal of time and effort. Therefore, the improvement of fatigue strength and fatigue life are mainly focused on by adopting residual stress(in this thesis). The compressive residual stress was imposed on the surface according to each shot velocity(57, 70, 83, 96 m/sec) based on Shot-peening, which is the method of improving fatigue lift: and strength. By using the methods mentioned above, I arrived at the following conclusions 1. The fatigue crack growth rate(da/dN) of the Shot-peened material was lower than that of the Un-peened material. And in stage I, ${\Delta}K_{th}$, the threshold stress intensity factor, of the shot-peen processed material is high in critical parts unlike the Un-peened material. Also m, fatigue crack growth exponent and number of cycle of the Shot-peened material was higher than that of the Un-peened material. That is concluded from effect of da/dN. 2. Fatigue life shows more improvement in the Shot-peened material than in the Un-peened material. And compressive residual stress of surface on the Shot-peen processed operate resistance force of fatigue crack propagation.

• 전기화학회지
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• 제3권2호
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• pp.72-75
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• 2000

For the purpose of developing the non-stoichiometric Zr-based Laves phase alloy with higher capacity and better performance for electrochemical application, extensive work has been carried out in KAIST. After careful alloy design of $ZrMn_2-based$ hydrogen storage alloys through varing their stoichiometry while susbstituting or adding some alloying elements, the $Zr-Ti-(Lh-V-Ni)_{2.2},\;Zr-Ti-(Mn-V-Cr-Ni)_{1.8\pm0.1}$ with high capacity and better performance was developed. Consequently the $Zr-Ti-(Mn-V-Ni)_{2.2}$ alloy has a high discharge capacity of 394mAh/g and shows a high rate capability equaling to that of commercialized $AB_5$ type alloys. On the other hand, in order to develop the hydrogen storage alloy with higher discharge capacity, the hypo-stoichiometric $Zr(Mn-V-Ni)_{2-\alpha}$ alloys substituted by Ti are under developing. As the result of competitive roles of Ti and $stocihiometry({\alpha})$, the discharge capacity of $Zr-Ti-(Mn-V-Cr-Ni)_{l.8\pm0.1}$ alloys is about 400mAh/g(410 mAh/g, which shows the highest level of performance in the Zr-based alloy developed. Our sequential endeavor is improving the shortcoming of Zr-based Laves phase alloy for commercialization, i.e., poor activation property and low rate capability, etc. It is therefore believed that the commercialization of Zr-based Laves phase hydrogen storage alloy for Ni-MH rechargeable battery is in near future.

• 한국산학기술학회논문지
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• 제14권3호
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• pp.1045-1053
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• 2013

플레저 보트나 요트는 FRP나 알루미늄으로 제작되고 있으나 FRP는 해양환경오염으로, 알루미늄은 낮은 가격 경쟁력으로 인하여 해당 제품의 시장 지배력이 약화되고 있다. 따라서 본 연구에서는 선체를 폴리에틸렌으로 제작하여 일본소형선박검사사무규정세칙에서 제안하고 있는 소형선체에 대한 구조 안전성 평가 방법을 통하여 폴리에틸렌 선체의 구조 안전성을 확인한 결과, 폴리에틸렌 보트가 FRP 보트보다 매우 높은 구조 안전성을 보였다.