• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.648-651
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• 2004

A vacuum system with ejector has been widely used because of its simple construction and easy maintenance. Ejectors are the main part of the vacuum system, of which designs determine the efficiency of vacuum system. The ejector with the capacity of 1.5 ton/hr steam consumption was designed and tested. The results showed that the tested values are satisfied with the designed specifications. Comparing with other ejectors designed by overseas specialist makers, it seems to have a good performance.

• Journal of the Korean Professional Engineers Association
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• v.34 no.5
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• pp.25-28
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• 2001

The Seoul World-Cup Stadium is a representative stadium of Korea that 2002 Korea-Japan World-Cup will be held in. It is designed for structural safety, economical efficiency during the construction, easy maintenance, and the utilization after the festival. Also, it is considered that this stadium has sufficient safety against the earthquake, wind, and snow through 3-dimensional dynamic analysis. In addition, We hope that 2002 Korea-Japan World-Cup gets great success.

• Proceedings of the KSR Conference
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• 2002.05a
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• pp.417-422
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• 2002

This paper describes the result of wearing test on the Sangju test track. The purpose of the test is to evaluate an amount of wearing for EMU's panto shoes. Panto shoes are affected in wearing by environment of owing to expose the vehicle. Especially, the rainy season, they are found easy to get an increase in wearing of panto shoes. To evaluate an amount of wearing, we ca]lied out running test for 5 months under the ground line conditions.

• Proceedings of the IEEK Conference
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• 2001.06e
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• pp.5-8
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• 2001

In this paper, we have space vector PWM(Pulse Width Modulation) circuits on the FPGA(Field Programmable Gate Arry) chip designed by VHDL(Very high speed integrated circuit Hardware Description Language). This circuit parts was required at controlling the AC servo motor system and should have been designed with many discrete digital logics. In the result of this study, peripheral circuits are to be simple and the designed logic terms are robust and precise. Because of it's easy verification and implementation, we could deduced that the customize FPGA chip show better performance than that of circuit modules parts constituted of discrete IC.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.11 no.18
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• pp.1-5
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• 1988

In this study we have provided one solution to overcome mistakes with limited technical staffs, capitals and times may be the computer for cost estimating. In view of the speed and the ability to draw on funds of information, we shall see that computer estimating models will become the exhibited and the accepted norm of operation by continuous research. Therefore, the computer is broadly serving the needs of many engineering disciplines and in the area of engineering design and industrial application, inexhaustible developed softwares are presented more easy speed and various application for Cost Engineering.

• YAKHAK HOEJI
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• v.47 no.5
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• pp.271-275
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• 2003

Easy and efficient synthetic route of novel 4'-C methyl branched carbocyclic nucleosides is described. The installation of alkyl and aryl groups at 4'-position of carbocyclic nucleosides were successfully made via sequential [3,3]-sigmatropic rearrangement and ring-closing metathesis (RCM) starting from simple ketones such as acetol. Adenine and uracil were coupled via Pd(0) catalyzed reaction, followed by desilylation to give novel compounds 13 and 14, respectively.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.89-92
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• 2004

Precast Segmental method was developed in germany 1950's. This method has been adoptted in long span girder mainly owing to easy construction effect. But, so far, The limit exists that this method is constructed in a portion of span and hard conveyance and foundation. This study was performed to analysis behavior difference of two rectangular section girder, spliced girder that was jointed 5-sliced 0.8m segment and monolithic girder that was produced in one body 4m span.

• Journal of the Korean Ceramic Society
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• v.27 no.5
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• pp.693-697
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• 1990

TIACA has two different side groups(ligands) as iso-propoxy groups and acetylacetonate groups. These two side groups have different hydrolysis rates. The two different rates of hydrolysis confer unique properties on TIACA, which are stability in aqueous solution and easy preparation of TiO2 and its multi components gels without precipitation. Their hydrolysis rates were monitored with I.R. and U.V. spectrophotometer.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.201-204
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• 2008

In this paper a new steganographic method is presented with minimum distortion. This paper focused on DCT rounding error and optimized that in a very easy way, resulting stego image has less distortion than other existing methods. The proposed method compared with F5 steganography algorithm, and the proposed method achieved better performance. This paper considered the DCT rounding error for lower distortion with possibly higher embedding capacity.

• Journal of Sericultural and Entomological Science
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• v.41 no.3
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• pp.201-204
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• 1999

The silk/paper mulberry paper was prepared by recycling of the hard twisted silk waste and its mechanical properties was investigated. The silk waste was pretreated with sodium hydroxide(0.5%) and sodium carbonate(4%) to make it easy for beating and fibrillation. The silk/paper mulberry hand sheet paper has better mechanical properties of tearing strength and air permeability compared with the traditional and modified traditional paper. Treating with alkaline solution, the hard twisted silk waste could be used for an novel composite material.