• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.363-368
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• 2000

This paper is an introduction of pessimum program for the identification of alkali-silica reaction of alkali-aggregate reaction which is known as one of a major factor of concrete deterioration. A series of gel-pat testing program was undertaken to observe the reactivity of potentially alkali-silica reactive concrete aggregates which were found to be reactive by previous petrographic examination (ASTM C 295). And then a pessimum program was performed in accordance with mortar-bar test method (ASTM C 227) with different percentage of those reactive components included in the fine aggregate source to determine the pessimum quantity. Chert and quartzite were found to be major components of reactive mineral/rock, and the pessimum condition for chert was about 3%, even though the test was performed with up to 25% of the component. In the case of quartzite, however, the mortar-bar expansion appeared to be directly proportional to the amount of quartzite sample with increasing tested quantity up to 35%. Both of the expansion results were well 3 and 6 month specified maximum limitation of 0.05% and of 0.1% respectively.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.6
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• pp.546-551
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• 2005

[ ${\beta}-1,3-Glucan$ ] (curdlan) is a water-insoluble polysaccharide composed exclusively of ${\beta}-1,3\;linked$ glucose residues. Extracellular curdlan was mostly synthesized by Agrobacterium species and Alcaligenes faecalis under nitrogen-limiting conditions. In this study, we screened the microorganisms capable of producing extracellular curdlan from soil samples. For the first time, we reported Gram-positive bacterium Bacillus sp. SNC 107 capable of producing extracellular curdlan in appreciable amounts. The effect of different carbon sources on curdlan production was studied and found that the yield of curdlan was more when glucose was used as carbon source. It was also found that maximum production was achieved when the initial concentration of ammonium and phosphate in the medium was 0.5 and 1.9 g/L respectively. In this study the curdlan production was increased from 3 to 7g/L in shake flask cultures.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1205-1211
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• 2003

Having information is most important at the present age. Internet is main source of obtaining information and mobile telecommunication let people communicate each other without any time and space limitation. Recently, advanced technology in telecommunication makes two-way service possible. So, the mobile internet service combined internet with mobile telecommunication is widely and rapidly promoted. Therefore user can transmit and receive a lot of information without time and space restriction using various application technologies. This paper deals with machinery that makes human do office work conveniently in vehicle using mobile internet service. Namely, it tries to design mobile internet machinery combining of wireless payment, GPS module, mobile internet, and mobile office etc. And that can transmit and receive e-mail or documents etc. This machinery has various objects, and design process has complexity. To reduce trial error and processing complexity, Axiomatic Design Method is used to design the machinery.

• Journal of the Korean Society of Clothing and Textiles
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• v.18 no.4
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• pp.460-472
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• 1994

The Purpose of this study was to find in the art the basis of originality appeared on the fashion design and investigating the erotic expression appeared on the ornaments how art surrealism, pop art, post moderninism-formularize in the modern fashion. This study about the expression of eroticism and modren costume, through the source of pictures contained in art books and mode magazine and documents investingation has resulted as follows: First, the formality and contents that related art and fashion shows us a various aspect. That based on modeled characteristic and various technique of the art. Second, the expression of eroticism in fashion expressed differently in style, material and expression method that is more strongly, sometimes metaphorically with spirit of the time's. Third, the expression of eroticism in fashion whether direct way or symbolic way has appeared as partial exposure of the body. It is appearing to the course that can display individuality of each person over the taboo of the part and the previous limitation of fashion.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.563-564
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• 2015

Recently, distributed generation using renewable energy resources have increased due to the limitation of conventional energy. To utilize these energy source effectively, a method of applying the energy storage system(ESS) in distribution system has been considered. In this paper, we simulated the one line-to-ground fault in power system with ESS. Based on these simulations, we analyzed the effect on Over Current Relay(OCR) operation. As a result, ESS operation modes result fault current fluctuation. Thus, OCR need to reset the pick up current. This paper analyze effect of ESS in distribution system according to OCR setting by using ElectroMagnetic Transient Program(EMTP).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.300-303
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• 2003

The design rule for 8.5kV LTT was discussed here. An inherent integrated breakover diode (BOD) for self -protection function and multi-amplified gate (AG) for improved di/dt capability of LTT was introduced in principle. The trade-off between light triggering input source and high dV/dt limitation has been treated via narrow grooved P-base for gate design. Key process technology for LTT was given, too.

• Archives of Reconstructive Microsurgery
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• v.17 no.1
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• pp.48-50
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• 2008

Loupes-assisted microsurgery often needs an operational head lamp for a better condition of light. This may cause serious neck fatigue due to the weight the operational head lamp, the limitation of the operator's head movement from the hind cable, and some cost for purchasing and management of it. On the contrary, a mountain head lamp is very light, full of freedom in movement, applicable to all types of loupes, and relatively very cheap. In conclusion, a mountain head lame can be a cost-effective light source for Loupes-assisted microsurgery.

• 한국신재생에너지학회:학술대회논문집
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• 2008.10a
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• pp.25-28
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• 2008

Steam reforming reaction is a matured technology to get hydrogen from hydrocarbon fuels compared with other reforming reactions such as partial oxidation(POX), autothermal reforming(ATR). It is so endothermic that it needs heat source to activate the reaction. Due to the reaction characteristics, heat transfer limitation phenomena generally occur in the steam reformer. As one of new ideas, the effect of discontinuous gas feeding is investigated based on heat transfer characteristics. The new operating method is usually favorable at high GHSV region(i.e. over $10,000h^{-1}$). In order to numerically simulate the physical issues, numerical approach is adopted based on heterogeneous reaction model, two-equation model in energy equation, and other constitutive models in porous media.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.421-421
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• 2012

Graphene has drawn enormous attention owing to its outstanding properties, such as high charge mobility, excellent transparence and mechanical property. Synthesis of Graphene by chemical vapor deposition (CVD) is an attractive way to produce large-scale Graphene on various substrates. However the fatal limitation of CVD process is high temperature requirement(around $1,000^{\circ}C$), at which many substrates such as Al substrate cannot endure. Therefore, we propose plasma enhanced CVD (PECVD) and decrease the temperature to $400^{\circ}C$. Fig. 1 shows the typical structure of RF-PECVD instrument. The quality of Graphene is affected by several variables. Such as plasma power, distance between substrate and electronic coil, flow rate of source gas and growth time. In this study, we investigate the influence of these factors on Graphene synthesis in vacuum condition. And the results were checked by Raman spectra and conductivity measurement.

• Journal of the korean Society of Automotive Engineers
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• v.6 no.4
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• pp.54-61
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• 1984

Numerical calculation of the flow field past a passenger car was carried out by using a panel method with a small computer of 5Mbyte memory size. The shape of car body was simplified and reconstructed by 2180 panels on which a constant strength sink (or source) was distributed. The separation of flow from the surface and the wake flow were not considered in the calculation because of the computer memory limitation. All of the results of calculation were presented by using a 3-dimensional computer graphics. In spite of small memory size of computer, generally good agreements were obtained, except the separated region, from the comparison of pressure distribution between numerical analysis and wind tunnel experiment with 1/5 scaled model.