• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.261-265
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• 2005

This paper describes the DC-DC Converter for Ancillary Power Supply in Hybrid Electric Vehicle. DC-DC Converter is used for charging 12V auxiliary battery supplying electric power to head ramp, audio, ECU etc in automobiles. used DC-DC Converter Topology is PS-ZVS FB(Phase Shifted Zero Voltage Switching Full-Bridge) to reduce switching loss and EMI noise induced by high frequency operating condition. And For easy compensation and stable system response characteristic, current mode control method including slope compensation is employed. Constant current / constant voltage charging control method guarantee stable electric charging of auxiliary battery. Simulation toll PSIM6.0 is used for initial circuit parameter settings and H/W debuging. Thermal problems of Switching components in DC-DC Converter is improved by using Thermo Tracer.

• Proceedings of the KIEE Conference
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• 1998.07g
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• pp.2544-2546
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• 1998

The electrical and physical charateristics of Pt-Co alloy thin films on $Al_2O_3$ substrate, deposited by r.f cosputtering respectively, were analyzed with thickness of thin films ($1700{\sim}10000{\AA}$) and increasing annealing temperature ($800{\sim}1000^{\circ}C$). At input power of Pt : 4.4 W/$cm^2$, Co : 6.91 W/$cm^2$, working vacuum of 10 mTorr and annealing conditions of $1000^{\circ}C$) and 60 min, the resistivity and sheet resistivity of Pt-Co thin films with thickness of $3000{\AA}$ was $15{\mu}{\Omega}{\cdot}cm$ and 0.5 ${\Omega}/{\square}$, respectively. The TCR value of Pt-Co alloy thin films was measured with various thickness of thin films and annealing conditions. The optimum TCR value of 3850 ppm/$^{\circ}C$ in temperature range($200{\sim}400^{\circ}C$) is gained under conditions $3000{\AA}$ of thin films thickness and $1000^{\circ}C$ of annealing temperature. The thermal charateristics of Pt-Co micro heaters were analysed with Pt-Co RTD integrated on the same substrate. In the analysis of characteristics of Pt-Co micro heaters, the Pt-Co micro heaters with thickness of $3000{\AA}$ and annealing temperature of $1000^{\circ}C$ had a good linearity and temperature is up to $468.2^{\circ}C$ with 2.1 watts of the heating power.

• Journal of Sericultural and Entomological Science
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• v.46 no.1
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• pp.28-31
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• 2004

Bombyx mori silk fibroin/hyaluronic acid blend films were prepared by mixing aqueous solution of B. mori silk fibroin and hyaluronic acid. According to the FTIR spectra, no interaction between silk fibroin and hyaluronic acid was found. The conformation of silk fibroin in blend films was changed from random coil to $\beta$-sheet structure by treatment of EDC ethanol solution. Thermal degradation peak of silk fibroin and hyaluronic acid was also not altered by blending each other. The average swelling ratio of silk fibroin/hyaluronic acid blend films was 70. Therefore, silk fibroin/hyaluronic acid blend films might be one of possible wound dressing materials.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.6
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• pp.1760-1767
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• 2008

In this study, we analyzed the physical and chemical properties such as proximate analysis, ultimate analysis, heating values, and thermogravimetric analysis for the organic sludges discharged from an industrial complex in Ulsan. The average water, combustible, and ash content of organic sludges were 72.9, 18.5, and 8.6%, respectively. And according to the ultimate analysis of organic sludges, the C, O, H, N, and S compositions were 33.9, 26.4, 4.4, 4.4, and 0.6%, respectively. According to the results of investigating the lower heating values, 6 sludges were on the range of $1,500{\sim}2,000\;kcal/kg$ and 4 sludges were on the range of over 2,000 kcal/kg. Therefore, these 10 sludges could be directly applied to industries which try to use the energy by direct incineration.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.8
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• pp.338-343
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• 2017

In this study, blast furnace slag powder was used in concrete to help reduce carbon dioxide emissions and to recycle industrial waste. Blast furnace slag powder is a byproduct of smelting pig iron and is obtained by rapidly cooling molten high-temperature blast furnace slag. The powder has been used as an admixture for cement and concrete because of its high reactivity. Using fine blast furnace slag powders in concrete can reduce hydration heat, suppress temperature increases, improve long-term strength, improve durability by increasing watertightness, and inhibit corrosion of reinforcing bars by limiting chloride ion penetration. However, it has not been used much due to its low compressive strength at an early age. Therefore, this study evaluates the effects of steam curing for increasing the initial strength development of concrete made using slag powder. The relationship between compressive strength, SEM observations, and XRD measurements was also investigated. The concrete made with 30% powder showed the best performance. The steam curing seems to affect the compressive strength by destroying the coating on the powder and by producing hydrates such as ettringite and Calcium-Silicate-Hydrate gel.

• Proceedings of the KIEE Conference
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• 2007.11a
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• pp.124-125
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• 2007

The composites were fabricated $\beta$-SiC and $TiB_2$ powders with the liquid forming additives of 8, 12, 16[wt%] $Al_2O_3+Y_2O_3$ as a sintering aid by pressureless annealing at $1,650[^{\circ}C]$ for 4 hours. Reactions between SiC and transition metal $TiB_2$ were not observed in the microstructure and the phase analysis of the pressureless annealed SiC-$TiB_2$ electroconductive ceramic composites. The relative density, the flexural strength, the Young's modulus and the Vicker's hardness showed the highest value of 82.29[%], 189.5[MPa], 54.60 [GPa] and 2.84[GPa] for SiC-$TiB_2$ composites added with 16[wt%] $Al_2O_3+Y_2O_3$ additives at room temperature. The relative density of SiC-$TiB_2$ composites was lowered due to gaseous products of the result of reaction between SiC and $Al_2O_3+Y_2O_3$. The electrical resistivity showed the lowest value of 0.012[${\Omega}{\cdot}cm$] for 16[wt%] at 25[$^{\circ}C$]. The electrical resistivity was all negative temperature coefficient resistance (NTCR) in the temperature ranges from 25[$^{\circ}C$] to 700[$^{\circ}C$].

• Pediatric Infection and Vaccine
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• v.24 no.2
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• pp.112-116
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• 2017

Kawasaki disease (KD) is an acute febrile mucocutaneous lymph node syndrome that commonly presents with stable hemodynamic status during the acute phase. An 8-year-old boy initially presented with severe hypotension and acute kidney injury. He was placed in the intensive care unit and was diagnosed with KD. Observed clinical features were defined as KD shock syndrome. His coronary artery was dilated during the subacute phase. Furthermore, he was given anti-hypertensive medications, owing to hypertension as an unusual complication of KD. We knew the importance of monitoring for blood pressure considering vasculitis as an aspect of the main pathogenesis of KD.

• Fire Science and Engineering
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• v.23 no.6
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• pp.10-15
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• 2009

Flame height calculation in a forest fire is a crucial part of predicting horizontal or vertical flame spread flared by radiation heat transfer. Flame height, which is one of the flame characteristics, can be estimated by the average height of luminous flame. This research relied on flame height observation test on P. densiflora surface fuel bed, which are surface combustibles in a forest, and calorimeter to measure Heat Release Rate, thus produced $H_f=0.027(\dot{Q'})^{2/3}$, flame height calculation equation for surface fuel. The research did not take into consideration such conditions as external velocity, slope and other variables that could affect flame height. According to comparison among experiment results, calculation results of the above formula and those of existing Heskestad formula (1998), it was found that standard error in fallen pine needles between experimental results and calculation results of the above formula amounts to 0.08, whereas standard error in same plant between experimental results and calculation results of existing Heskestad formula amounts to 0.23.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.3
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• pp.593-598
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• 2008

It was made a friction material of various kinds by adding 10%, 20% and 30% of reduced iron. It was obtained by a connected-reduced process in a blast furnace sludge and oxidized iron, instead of $BaSO_4$, which is already a used inorganic filling material among a component of a brake friction material. This was done by a basic physical property test, a friction performance test to use a brake dynamometer. Moreover, in case of an add in the friction material, instead of using $BaSO_4$, the more expensive filling material, the reduced iron was also better because it has an excellent a friction property of an exothermic temperature, wear, etc. was 10%. At G1 and G3 specimens, a shear strength and a bonding strength of the friction material was decreased to be able to increase an amount of the blast furnace sludge and the reduced iron, but an application of all friction materials appeared enough strength.

• Journal of the Korean Applied Science and Technology
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• v.31 no.3
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• pp.345-351
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• 2014

Dinitramide ($N(NO_2)_2$) salts are one of plausible oxidizing agents for a high efficient propellant. Guanidine dinitramide (GDN) is an organic salt improving its stability against moisture, so that enables massive production and long term storage. Several types of GDN (GDN-1,2,3,4,5) were synthesized using some types of starting materials such as guanidine acetate, chloride, carbonate, nitrate and sulfate. As a result of the experimental work, synthesized GDN from the carbonate salt appeared fairly pure relatively higher yield (99%) than the other samples. The absorption wave length of all prepared GDNs by FTIR were found at 3452, 3402, 3354, 3278, 3208, 1642, 1570, 1492, 1416, 1337, 1179 and $1000cm^{-1}$. DSC analysis found a thermal phase change at $130^{\circ}C$, and indicated exothermic reaction at about $150^{\circ}C$ to $160^{\circ}C$.