• Journal of the Korean Society of Manufacturing Process Engineers
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• v.3 no.3
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• pp.32-38
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• 2004

Recently, the system of high speed milling(HSM) is widely used for reducing the operation time and maximizing efficiency of work. The most research of high speed milling system is still leaves much to be desired. Specially the research of mass pocket high speed processing with high precision is the first and probably the last. So this paper showed mass pocket processing of high precision with a duralumin and then confirmed a cause of inferior goods through the CAD/CAM pattern simulation and experimentation. And this paper showed high speed processing system reduce the rate of inferior from this optimal pattern.

• Preventive Nutrition and Food Science
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• v.13 no.2
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• pp.71-76
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• 2008

This study was performed to examine the effects of onion powder supplementation on lipid metabolism in male SD rats fed a high fat and high cholesterol diet. Experimental groups were control (C), high fat fed group (HF), high fat+onion powder intake (OP), high fat+quercetin intake (Q). The HF diet contained 1% cholesterol, 4% lard, 0.3% Na-taurocholate, and quercetin supplementation level was 0.1 g/kg diet. The OP group showed lower body weight gains compared to the control, while there was no significant difference in food efficiency ratio efficiency. When the proportion of fecal bile acids per total lipids was calculated, there was a significant decrease in the HF group compared to the control group, while the levels of the control group was same as that of the OP group. There was no significant difference between the HF and Q groups in bile acid/total lipid in feces. The amount of total cholesterol in liver increased significantly in HF group compared to the control group, while total cholesterol decreased significantly in the OP group compared to the HF group. There was a significant decrease in GOT (glutamic oxaloacetic transaminase) activity in OP and Q groups compared to the HF group. In conclusion, feeding onion powder to hyperlipidemic rates appeared to control weight gain, significantly lower the level of total cholesterol in the liver, and recover GOT activity. We also demonstrated that onion powder intake was more effective than quercetin intake.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.928-929
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• 2008

A dc/dc power conversion system using multi stage capacitor is proposed in this paper. The proposed new type converter is designed from high efficiency dc/dc converter with fixed boost ratio and variable voltage converter. The tests have been done using PSIM computer simulation to confirm the analysis and control concept.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.6
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• pp.3742-3752
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• 2015

This study aims to examine and analyze consumers' perception level and purchase behavior of organic clothing goods with. According to their purchase experience of organic clothing goods, it was found that organic textile products for women like sanitary pad were most and purchase frequency of organic clothing goods was mostly once. Among reasons to purchase organic clothing goods, 'for my health' was most. Non-purchase reason was mostly 'I don't know what organic goods are'. Therefore, there were significant awareness differences of organic clothing goods in "health efficiency" between the purchasing group and the non-purchasing group. In addition, there were significant awareness differences of demographic characteristics and organic clothing goods in sex, age, and "health efficiency" of related major items and in "high quality recognition" and "health efficiency" of residential areas.

• Journal of the Korean Applied Science and Technology
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• v.35 no.3
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• pp.876-885
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• 2018

Utilization of spent RHDM(Residue Hydrodemetallation) catalyst as de-NOx SCR(Selective Catalytic Reduction) catalyst was studied by conducting by heptane cleaning and high-temperature roasting for removal of deposited carbon and sulfur. Followed by oxalic acid leaching was carried out for controlling excess vanadium deposited on spent RHDM catalyst in search of appropriate vanadium loadings for the best SCR performance and the leaching conditions are 5~15wt% concentration of oxalic acid and 5min leaching time at $50^{\circ}C$ with the ultra-sonic agitator. De-NOx activities of prepared and commercial SCR catalyst were measured by the atmospheric SCR catalyst performance test unit, their residual content were also carried out by ICP, C&S Analysis and XRF. Acid leaching (AL-10) catalyst showed the highest de-NOx efficiency of all prepared catalysts and the de-NOx efficiency over wash coated catalyst(WC-AL-10) was equivalent to that of commercial SCR catalyst. Therefore the possibility of using as SCR catalyst for each application by adjusting treatment conditions of spent RHDM catalyst was found and further research will be needed in detail for the its commercialization.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.6
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• pp.2826-2832
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• 2012

A smart grid is an electric-power grid that employs a new information technology.This technology makes it possible to exchange real-time energy information between suppliers and consumers, finally resulting in high energy efficiency. The energy management system in smart grid provides up to date information on electricity consumption as well as dynamic electricity price to consumers of smart grid system. However, the existing energy management systems only focus on pricing system, for example, real-time electricity prices. In this paper, we try to improve the existing energy management system and propose the energy management system that mainly focuses on the efficiency of electricity consumption. In the proposed management system, PMU(Phasor Measurement Units) installed in switchboards gathers electricity data in a real time. We also propose to use data mining method, which is applied to analyzed electricity data for improving energy efficiency. Also, the proposed energy management system is designed to efficiently control the electricity between PMU and management system in case of a shortage of electricity or surplus electricity.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.6
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• pp.407-416
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• 2014

Five factors are identified, which affect the performance of optical filter: 1) type of optical glass, 2) existence of Fe, 3) photo pic coating type, 4) coating form, and 5) coating thickness. If we consider all the levels of five factors, there are 360 possible candidates. We determined five evaluation criteria, which can be used to evaluate possible candidates. For the performance measures we selected white-state avearge voltage, black-state average voltage, and black-state error rate. And we added economic criterion and quality and maintenance criterion. Through the two-step statistical analysis of white-state avearge voltage, black-state average voltage, and black-state error rates, we selected final four candidates. Based on the five criteria we finally determined optimal optical filter using AHP.

• Transactions on Electrical and Electronic Materials
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• v.5 no.1
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• pp.1-6
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• 2004

Zinc sulfide is a semiconductor with wide band gap and high refractive index and hence promising material to be used as ARC on commercial silicon solar cells. Uniform deposition of zinc sulfide (ZnS) by using chemical bath deposition (CBD) method over a large area of silicon surface is an emerging field of research because ZnS film can be used as a low cost antireflection coating (ARC). The main problem of the CBD bath process is the huge amount of precipitation that occurs during heterogeneous reaction leading to hamper the rate of deposition as well as uniformity and chemical stoichiometry of deposited film. Molar concentration of thiorea plays an important role in varying the percentage of reflectance and refractive index of as-deposited CBD ZnS film. Desirable rate of film deposition (19.6 ${\AA}$ / min), film uniformity (Std. dev. < 1.8), high value of refractive index (2.35), low reflectance (0.655) have been achieved with proper optimization of ZnS bath. Decrease in refractive index of CBD ZnS film due to high temperature treatment in air ambiance has been pointed out in this paper. Solar cells of conversion efficiency 13.8 ％ have been successfully achieved with a large area (103 mm ${\times}$ 103 mm) mono-crystalline silicon wafers by using CBD ZnS antireflection coating in this modified approach.

• Korean Chemical Engineering Research
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• v.50 no.5
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• pp.837-842
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• 2012

A pilot scale circulating fluidized boiler (CFB) for refuse derived fuel (RDF) is designed and constructed to demonstrate a performance of CFB technology for waste fuel utilization. The boiler has a design capacity of 6 MWth with $400^{\circ}C$ 38 ata steam generation performance. The maximum steam rate of the boiler was about 8 ton/h. The main component of the fuel was RDF (Refuse Derived Fuel) with high volatile contents and showed fast ignition and easy combustion. The pilot plant showed over 99.5% of combustion efficiency. Stable operation of RDF CFBC depended on the content of non combustion materials other than ash and fast removal of them. Emission level was under legal limit except that of HCl without external flue gas treatment facilities. Also about 60% of fuel chlorine was absorbed to fly ash particles. For HCl emission control flue gas treatment technology is required such as wet and dry scrubber in order to comply with Korean regulation.

• Korean Journal of Childcare and Education
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• v.11 no.1
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• pp.83-100
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• 2015

The purpose of this study is to find out the effects of directors' leadership style and the type of decision-making on improving child care teachers' job satisfaction which is essential to operate high-quality nursing. The survey method was used for 184 child care teachers who work for child care centers. The collected data were analyzed using one-way analysis of variance and posteriori test to find out the differences in teachers' job satisfaction according to their recognition of directors' leadership and decision-making. The result showed that differences exist in child care teachers' job satisfaction according to the leadership and decision-making of directors as recognized by the teachers. The score of child care teachers' self-development, work, welfare & social stability related to job satisfaction hit the highest when directors' leadership type was efficiency-centered. Similarly, participatory decision-making type, which is the most ideal type, scored the highest in all sub-components of job satisfaction in the case of directors' type of decision-making. This implies that the directors who prefer positive leadership and democratic participatory decision-making type increase teachers' job satisfaction which will positively affect the child care centers' qualitative development.