• Proceedings of the KIEE Conference
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• 1999.07a
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• pp.461-464
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• 1999

To improve traction effort performance and stability for the Korean High-Speed Railway Train, practical re-adhesion controller including a novel anti-slip control scheme is proposed. The presented method is verified by train running simulation results based on induction motor vector control with PWM inverter.

• Progress in Superconductivity and Cryogenics
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• v.13 no.1
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• pp.1-5
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• 2011

[ $CeO_2$ ]has been widely used for single buffer layer of coated conductor because of superior chemical and structural compatibility with $ReBa_2Cu_3O_{7-{\delta}}$(Re=Y, Nd, Sm, Gd, Dy, Ho, etc.). But, the surface of $CeO_2$ layer showed cracks because of the large difference in thermal expansion coefficient between metal substrate and deposited $CeO_2$ layer, when thickness of $CeO_2$ layer exceeds 100 nm on the biaxially textured Ni-3%W substrate. The deposition rate has been limited to be less than 6 $\AA$/sec in order to get a good epitaxy. In this research, we deposited $CeO_2$ single buffer layers on biaxially textured Ni-3%W substrate with 2-step process such as thin nucleation layer(>10 nm) with low deposition rate(3 $\AA$/sec) and thick homo epitaxial layer(>240 nm) with high deposition rate(30 $\AA$/sec). Effect of deposition temperature on degree of texture development was tested. Thick homo epitaxial $CeO_2$ layer with good texture without crack was obtained at $600^{\circ}C$, which has ${\Delta}{\phi}$ value of $6.2^{\circ}$, ${\Delta}{\omega}$ value of $4.3^{\circ}$ and average surface roughness(Ra) of 7.2 nm within $10{\mu}m{\times}10{\mu}m$ area. This result shows the possibility of preparing advanced Ni substrate with simplified architecture of single $CeO_2$ layer for low cost coated conductor.

• Journal of the Korean Wood Science and Technology
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• v.48 no.2
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• pp.154-165
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• 2020

To assign the functionality of the regenerated fiber from waste MDF(wMDF) made of pitch pine, we examined the dyeing characteristics of natural dyes, sappan wood as a polychromatic natural red series, monochromatic gardenia as a yellow series, and indigo blue series. For nonemordanting dye, the colors of regenerated fiber dyed by sappan wood and gardenia were reddish yellow (YR) and yellow (Y) series, respectively, and dyeing conditions were appropriate a 30 ~ 50 g/L of dyeing materials at 60 ℃ for 60minutes of dyeing time. We obtained regenerated woody dyed fibers (Re-WDF), YR to the red (R) series by premordanting with Al and Cu mordant for sappan wood and the purplish red (RP) series by Fe premordanting. In the case of gardenia, only Y series colors were developed in nonemordanting dye or all three mordants. Indigo dye produced Re-WDF with greenish yellow (GY) tone at 1%, green (G) tone at 3%, and blue (B) tone at 5% concentration or more. Re-WDF with indigo showed the best light fastness followed by sappan wood and gardenia. In particular, the light fastness of Re-WDF with gardenia was very poor. The light fastness was somewhat improved by premordanting(Fe>Cu>Al) both sappan wood and gardenia dyes.

• Journal of Energy Engineering
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• v.23 no.3
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• pp.17-20
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• 2014

A magnetic fluid separation technology was confirmed to be very effective to remove the suspended solids from contaminated water. We have surveyed on the effects of operating variables on the characteristics of suspended solids(SS) removal investigated through the test runs using magnetic powder. Magnetic flocculation here formed by adsorbing fine magnetites on the surface of suspended solid was observed. The strength of magnet was of significance in determining the SS removal efficiency.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.3
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• pp.381-385
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• 2006

This study examined the influence of re-growth periods on chemical composition, biomass production, nutritive value and digestion kinetics of Setaria sphacelata (SS) and Cenchrus ciliaris (CC) in ruminally cannulated buffalo bulls. Two re-growth intervals i.e. clipping every month ($CI_1$) and clipping after every two months ($CI_2$) were compared with the control (clipped after 4 months). Mean values of leaf to stem ratio in SS and CC grasses were decreased (p<0.05) with increasing re-growth interval. The lowest leaf to stem ratio was recorded in control plots of both grasses. In both grasses, increasing growth period increased the concentrations of dry matter (DM), neutral detergent fiber (NDF) and organic matter (OM) and decreased crude protein (CP). Mean dry herbage, OM and CP yields of SS and CC were increased (p<0.05) with increasing re-growth interval. Ruminal DM and NDF digestibilities of SS and CC were decreased (p<0.05) with increasing interval. Ruminal rate of DM and NDF disappearance was higher while the ruminal lag time of these nutrients was lower with monthly than with bi-monthly clipping interval. The results from present study imply that SS and CC clipped after every two months is more beneficial than when clipped every month or every four months in terms of optimal biomass with adequate nutritional value for buffaloes.

• Proceedings of the Korean Vacuum Society Conference
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• 2003.08a
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• pp.68-68
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• 2003

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.3
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• pp.60-68
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• 2008

This work describes a re-configurable 10MS/s to 100MS/s, low-power 10b two-step pipeline ADC operating at a power supply from 0.5V to 1.2V. MOS transistors with a low-threshold voltage are employed partially in the input sampling switches and differential pair of the SHA and MDAC for a proper signal swing margin at a 0.5V supply. The integrated adjustable current reference optimizes the static and dynamic performance of amplifiers at 10b accuracy with a wide range of supply voltages. A signal-isolated layout improves the capacitor mismatch of the MDAC while a switched-bias power-reduction technique reduces the power dissipation of comparators in the flash ADCs. The prototype ADC in a 0.13um CMOS process demonstrates the measured DNL and INL within 0.35LSB and 0.49LSB. The ADC with an active die area of $0.98mm^2$ shows a maximum SNDR and SFDR of 56.0dB and 69.6dB, respectively, and a power consumption of 19.2mW at a nominal condition of 0.8V and 60MS/s.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.28-29
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• 2006

The magnetic properties of a series of both annealed and as-rolled Ni-$W_y$ alloy tapes with compositions y = 0, 1, 3, and 5 at.%, were studied. To compare with Ni-W alloys, the magnetic properties of a series of both annealed and as-rolled $[Ni_{97at.%}W_{3at.%}]_{100-x}Cu_x$ alloy tapes with compositions x = 0, 1, 3, 5 and 7 at.%, were studied, as well. Both the isothermal mass magnetization M(H) of a series of samples, such as both Ni-W and [Ni-W]-Cu alloy tapes, at different fixed temperatures and M(T) in fixed field, were measured using a PPMS-9 (Quantum Design). The degree of ferromagnetism of Ni-$W_y$ alloys have reduced as W-content y increases. Both the saturation magnetization $M_{sat}$ and Curie temperature $T_c$ decrease linearly with W-content y, and both $M_{sat}$ and $T_c$ go to zero at critical concentration of $y_c$ ~ 9.50 at.% W. The effect of Cu addition on both the saturation magnetization $M_sat$ and Curie temperature $T_c$ decrease linearly with Cu-content x in $[Ni_{97at.%}W_{3at.%}]_{100-x}Cu_x$ alloy tapes with compositions x = 0, 1, 3, 5, and 7 at.%. The results confirm that [Ni-W]-Cu alloy tapes can have much reduced ferromagnetism as Cu-content x increases.

• International Journal of Automotive Technology
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• v.4 no.1
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• pp.31-40
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• 2003

W-beam guardrail system has been the most popular roadside safety device around the world. Through large plastic deformation and corresponding energy dissipation, a W-beam guardrail system contains and re-directs out-of-control vehicles so as to reduce the impact damage on the vehicle occupants and the vehicles themselves. In this paper, our recent experiments on 1 : 3.75 downscaled W-beam and the beam-post system are reported. The static and impact test results on the load characteristics, the global response and the local cross-sectional distortion are reveled. The effects of three different end-boundary conditions for the beam-only testing are examined. It is found that the load characteristics are much dependent on the combined contribution of the local cross-sectional distortion and the end-supporting conditions. The energy Partitioning between the beam and the supporting Posts in the beam-Post-system testing were also examined. The results showed that the energy dissipation partitioning changed with the input impact energy. Finally, a simple mass-spring model is developed to assess the dynamic response of a W-beam guardrail system in response to an impact loading. The model's prediction agrees well with the experimental results.

• Electronics and Telecommunications Trends
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• v.28 no.4
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• pp.118-131
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• 2013

최근 과학 및 IT 패러다임은 HW(과거) 및 SW(현재) 중심에서 '데이터 빅뱅'을 활용하여 정치 사회 경제 등 제반 이슈와 연계된 분석 예측으로 진화 중이다. 국가안전 및 위험관리, 의료, 교육, 복지, 환경 등 사회 전반에 걸쳐 공공부문에서의 빅데이터 활용 가능성이 높아지고 있다. 공공정보 자체뿐만 아니라 민간정보와의 통합 분석을 통해 효과적인 맞춤형 정책과 새로운 지식정보 서비스 제공이 가능하기 때문에 주요 선진국은 공공정보의 적극 활용을 위해 다양한 정책을 경쟁적으로 추진해 오고 있다. 공공정보의 민간활용 촉진은 정보 제공자인 공공기관뿐만 아니라, 이를 활용하는 민간 사업자, 관련 서비스 사용자 모두에게 경제적 비경제적 가치를 제공할 수 있다. 따라서, 본 연구를 통해 국내 공공정보 민간활용 산업의 경제적 파급효과를 추정하고, 중요한 전 후방 연결 산업들을 파악하고자 한다.