• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1708-1713
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• 2003

The acceptance test of KTX has been performed in Korea. During the test, lateral vibration of carbody over the accepted value called swat was found. KTX has 20 car trainsed formation whose trailer cars are linked by articulate bogies. So this study is performed to see the effects of long trainsed formation on vehicle dynamics and the train stability by 20 car vehicle model. Firstly the reliable vehicle model which shows well the tendencies appeared in the tests on the high speed test line is required to find the cause of lateral vibration and the countermeasure. Vehicle model was made for the analysis with VAMPIRE. The analysis results show that secondary air spring lateral stiffness is the most significant parameter to cause carbody lateral vibration. Mode analysis results show that he least damped mode shape is similar to the vibration pattern shown in the tests that the amplitude of the motion increases along the train set and decreases in the tail part. For the case of short train formation with 7 or 10cars, sway does not happen. But in the case of longer train formation with 16 or 20 cars, sway was found.

• Transactions of Materials Processing
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• v.7 no.5
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• pp.432-438
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• 1998

The process variables i.e. the speed of forming, the ratio of thickness to diameter the shape of formed materials and the reduction of area were selected in order to study the process of the rotary swaging. It was found that the process variables affected the quality of products, i.e. the hardness the surface roughness and the degree of precision of products. Variation of hardness in deformed samples was mainly dependent on the reduction of area. Upon forming tubes applying the t/D ration higher than 1/10 led to the formation of defects on products which may be reduced by application of mandrels.

• Transactions of Materials Processing
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• v.21 no.3
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• pp.160-163
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• 2012

In this paper, a new approach to finite element analysis for tube swaging is presented. An analysis model is developed with emphasis on the pusher that imposes back pressure in order to keep the workpiece from slipping along the die-workpiece interface especially when tapered dies are used. A rigid-plastic finite element method is employed. The approach is to simulate the tube swaging process and the results are compared quantitatively with predictions, showing close agreement with each other.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2002.05a
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• pp.51-56
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• 2002

In this paper, the stress and deformation characteristics of the high pressure hose that have the hose components such as rubber, braid and steel( sleeve and nipple) during the manufacturing process, and analyzed using the [mite element method The swaging process is modeled with a contact problem in identical conditions of real circumstances, and the properties of hose materials based on the experimental data are used in this analysis. Also, to understand the effect of the nipple protrusions on the deformation characteristics of a power steering hose among the steel materials shape of the existing model, and changed the steel materials shape partially, and compared with the existing model.

• Textile Coloration and Finishing
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• v.31 no.4
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• pp.258-267
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• 2019

Synthetic suede without PFCs(perfluorinated compounds) are followed by subsequent high temperature treatment. But migration fastness of synthetic suede may be reduced due to sublimation of disperse dyes that results from the high temperature treatment. Therefore, in this study, chitosan treatment was used to improve the migration fastness before polyurethane dipping process. Polyester fiber was treated with sodium hydroxide aqueous solution before chitosan processing. This samples treated with a chitosan concentration upto 0.5% were dyed and coated with PUD(polyurethane dispersion). The migration fastness was most improved at 0.35% application. This is presumably due to the fact that the chitosan may increase the dye-binding capability through intermolecular hydrogen bonding.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.5
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• pp.1102-1106
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• 2008

It's necessary to invent a measure to deal with expected counter results when observing mechanical behaviors under the various operations and it can be done by measuring the stress and deformation characteristics of the Automotive Air-Conditioner Hose, which is a hose made up of a rubber hose, an aluminum sleeve and pipe. In this paper, characteristics of the stress and deformation characteristics of the Automotive Air-Conditioner Hose which plays an important role in circulation of refrigerant of an air conditioner in an automobile are analyzed using the finite element method.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1997.03a
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• pp.273-280
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• 1997

Rotary swaging is a process for reducing the cross-sectional area or changing the shape of bar, tube or wires by repeated radial blows with one or more parirs of opposed dies. The present study is concerned with investigation the effect of process parameters upon product quality(hardness, roughness, precision of dimension). To enhance the product quality, experimental works are carried out for some process parameters such as forming speed, billet shape, lubrication, reduction of area and ratio of t/D. Rod shift formed by RSM25 under cold conditions has good surface quality, hardness and precision of dimension. The recommendable process conditions are suggested for solid and tubular products.

• Journal of Industrial Technology
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• v.26 no.B
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• pp.127-134
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• 2006

As material needs have been increasing with recent economic growth, it is a current tendency that the magnitude of load applied to structure has been rising. With improved technique of product materials, steel and concrete have been stranger than ever so the danger of fatigue damage increases as permanent action of repeated loads. In case of deformed steel bars widely used in reinforced concrete structure, when they are product in factory, there will exist same parts connecting the steels. Such connections are easy to be weakened by permanent action of repeated loads. It is a real condition in Korea that there is lack of research of it. As a result of estimating fatigue characteristic of Pressure Welded joints with the steels that are oftenly used and producted in domestic it is showed that there are no remarkable difference in fatigue strength. Because there is no detail which is refered in Civil Specification, this paper will be the basic data being added in later Specification.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.692-697
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• 2001

It is necessary to analyze the mechanical behaviors of the power steering hose, which must play a proper role under severe operating conditions, in order to prepare a preventive measure fur contrary effects expected in unfavorable circumstances. In this paper, the stress and deformation characteristics of the hose components such as rubber, sleeve, nipple and reinforced braids during the swaging process, are analyzed using the finite element method. Contact conditions identical to the manufacturing process are taken into account, and the material properties based on experimental data are used in the analysis. Investigations into the mutual relations between the manufacturing conditions and the hose performances are done with respect to the jaw stroke on the basis of the stress and strain values of the hose components after swaging process.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2009.05a
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• pp.243-244
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• 2009

The purpose of this study was to investigate the preference and the sensibility for velvet, suede, and corduroy fabrics of the university students. A questionnaire survey was conducted on 153 female students in the Cheongju area, Korea. Frequency, F-test and factor analysis were used for data analysis. Female students preferred velvet and suede fabrics, but they did not prefer corduroy fabrics. They evaluated that velvet fabrics express varied sensibility. They considered that velvet fabrics have a more sexy and chic image than those of corduroy.