• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2001.12a
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• pp.177-180
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• 2001

The subject of this paper is to efficient Pm duty contort for two DC motor synchronousness in the system. Fuzzy controller have been successfully applied to many uncertain and complex industrial plant. So, It adapted fuzzy controller using compositional fuzzy rule so that change PH duty for speed control if the length of destination is different, And for unknow plant, it is the study to make the unknow transfer function system with fuzzy control method. This controller has been successfully applied to Pm duty control for the system synchronousness.

• Proceedings of the Korean Magnestics Society Conference
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• 2005.12a
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• pp.106-106
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• 2005

• Journal of the Korean institute of surface engineering
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• v.34 no.6
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• pp.531-536
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• 2001

Co-22 %Cr alloy films are promising for high-density perpendicular magnetic recording media with their perpendicular anisotropy and large coercivity of 3000 Oe. We observed that a self organized nano structure (SONS) of fine ferromagnetic Co-enriched phase and paramagnetic Cr-enriched phase appears inside the grain of Co-Cr magnetic alloy thin films at the elevated substrate temperature after do-sputtering. The periodic fine Co-enriched phase and Cr-enriched phase is the plate shape of 80 (equation omitted)-wide and 1000 (equation omitted)-long. Cr-enriched phases are located at the center of grains. We prepared 5000 (equation omitted) -thick Co-22 %Cr films on polyimide substrate with varying substrate temperature of $ 30^{\circ}C$, $ 150^{\circ}C$ ,200 $^{\circ}C$, $300^{\circ}C$, and $400^{\circ}C$, respectively. A transmission electron microscope equipped with energy dispersive X-ray analyzer is employed to observe the microstructure of each samples after Co-enri-ched phase are etched selectively. The self organized nano structure of Co-enriched and Cr-enriched lamellar is observed above the substrate temperture of $150^{\circ}C$. No compositional change is observed with substrate temperature. The compositional phase separation in self organized structure becomes clear as the substrate temperature increases. Our results implies that the self organized nano structure in Co-22 %Cr film is ideal for ultra high density recording media by recording selectively on Co-enri-ohed phase.

• Journal of the Korean Ceramic Society
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• v.56 no.2
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• pp.173-177
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• 2019

Thermal properties of a SiO₂-B₂O₃-BaO ternary glass system depending on compositional change of BaO have been examined to find a proper sealing material for reversible oxide cells. Glass transition temperature and thermal expansion coefficients increased simultaneously up to 55 mol% of BaO content. The structural role of BaO with regard to the thermal properties has been discussed on the basis of Raman spectroscopy results. Flowability of the glass at sealing temperature has been examined with packed glass powders of 12 mm diameter along with a high temperature optical microscope. The practical sealing property of the glass was also examined with YSZ coated with NiO-yittria stabilized zirconia (NiO-YSZ) and it showed good adhesion without noticeable reaction with NiO-YSZ layer.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.1208-1211
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• 2003

High quality $Bi_2Sr_2Ca_nCu_{n+1}O_x$ superconducting thin films fabricated by using the evaporation method at various substrate temperatures, $T_{sub}$, and ozone gas pressures, $pO_3$. The correlation diagrams of the $Bi_2Sr_2Ca_nCu_{n+1}O_x$ phases with $T_{sub}$ and $pO_3$ are established in the 2212 and 2223 compositional films. In spite of 2212 compositional sputtering, Bi2201 and Bi2223 as well as Bi2212 phases come out as stable phases depending on $T_{sub}$ and $pO_3$. From these results, the thermodynamic evaluation of ${\Delta}H$ and ${\Delta}S$, which are related with Gibbs' free energy change for single Bi2212 or Bi2223 phase, was performed.

• Food Science and Biotechnology
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• v.18 no.2
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• pp.481-487
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• 2009

The compositional changes of wormwood (Artemisia princeps var. orientalis) essential oils were studied under 4 different storage conditions i.e., being exposed to air at 20 and $40^{\circ}C$. Sixty-four volatile compounds consisting of 24 terpene hydrocarbons, 18 alcohols, 11 ketones, 6 esters, 1 aldehyde, 2 hydrocarbons, and 2 oxides were identified on the basis of their mass spectra characteristics and retention indices in original wormwood essential oils. Identified compounds constituted 80.53% of the total peak area. Borneol (12.13%) was the most abundant compound, followed by $\alpha$-thujone (8.66%), T-cadinol (6.67%), and 1,8-cineole (6.21%) in original wormwood essential oils. Under the condition of $40^{\circ}C$ of temperature with the cap being opened for 3 min everyday respectively during 6 months of storage, the total amount of functional groups in essential oil determined by peak area percent were decreased by 79.45%, at most. The total level of monoterpene hydrocarbons decreased markedly in the aerobic condition and high temperatures. Whereas the total level of esters increased significantly. Wormwood essential oils were stored in experimental conditions, with the changes in the volatile compounds of essential oils being accelerated by high temperatures and contact with the atmosphere.

• Journal of the Korean institute of surface engineering
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• v.31 no.2
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• pp.81-90
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• 1998

NiCrAly/YSZ(8wt% Y2O3-Zro2) functionally fraded thermal barrier coating (FGC) layers on a Co-base sureralloy (HAYNESS 188) substrate were fabricated using Ar shielded single torch air plasma spraying method. Functional grading were produced with the stepwise compositional change throughout layer thinkness. Microstructural observation revealed a sucessful fabrication of NiCrAly/YSZ FGC. From the results of the curvature measurement, adhesive stength measurement and thermal shock test for the FGC, it was concluded that the optimum enhance of functionally graded coating layer thinkcess and compositional pattern exit to enhance the properties of FGC, which is closely reated to the internal residual distribution with it.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.04a
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• pp.70-73
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• 2006

High quality $Bi_2Sr_2Ca_nCu_{n+1}O_x$ superconducting thin films fabricated by using the evaporation method at various substrate temperatures, $T_{sub}$, and ozone gas pressures, $pO_3$. The correlation diagrams of the $Bi_2Sr_2Ca_nCu_{n+1}O_x$ phases with $T_{sub}$ and $pO_3$ are established in the 2212 arid 2223 compositional films. In spite of 2212 compositional sputtering, Bi2201 and Bi2223 as well as Bi2212 phases come out as stable phases depending on $T_{sub}$ and $pO_3$. From these results, the thermodynamic evaluation of ${\Delta}H$ and ${\Delta}S$, which are related with Gibbs' free energy change for single Bi2212 or Bi2223 phase, was performed.

• Journal of Ceramic Processing Research
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• v.19 no.6
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• pp.450-454
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• 2018

In recent years, thermal insulation coating technology for automotive engine parts has received significant attention as a means of improving the thermal efficiency of automotive engines. One of the characteristics of thermal insulation coatings is their low thermal conductivity, and, materials such as YSZ (Yttria-stabilized zirconia), which have low thermal conductivity, are used for this purpose. This research presents a study of the changes in the microstructure and thermal conductivity of $8YSZ/SiO_2$ multi compositional thermal insulation coating for different compositions, and particle size distributions of suspension, when it is subjected to suspension plasma spraying. To obtain a porous coating structure, the mixing ratio of 8YSZ and $SiO_2$ particles and the particle sizes of the $SiO_2$ were changed. The microstructure, phase formation behavior, porosity and thermal conductivity of the coatings were analyzed. The porosities were found to be 1.2-32.1%, and the thermal conductivities of the coatings were 0.797-0.369 W/mK. The results of the study showed that the microstructures of the coatings were strongly influenced by the particle size distributions, and that the thermal conductivities of the coatings were greatly impacted by the microstructures of the coatings.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.5
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• pp.129-136
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• 2012

On this study, $CO_2$ gas, net of Ar gas, and mixed gas in solid wire(AWS ER 70S-6) and flux cored wire(AWS E71T-1) were used to weld on Mild steel(SS400). After the progress, the status changes of the welds in Mild steel(SS400) were investigated with compositional changes. For stable experiments, welding was conducted using the automatic feeder. Radiation testing, hardness testing, chemical composition analysis and penetrated cross-section were measured. Through these experiments, shapes of penetrated cross-section, chemical composition changes, and weld defects according to the variation of welding gas were known. Weld defects and weld cross-sectional shapes by the variation of the welding voltage were also detected.