• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.10a
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• pp.106-109
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• 2008

Polyurethane has been one of the most important materials for automobile elastic parts such as bumper, head rest, instrument panel and so on since it covers very wide range of mechanical characteristics with low production costs. The process variables such as formulation of ingredients and mold temperature, mixing speed, etc. can affect the quality of produced polyurethane foams so that process conditions should be determined appropriately. In this study, foaming behaviors of semi-rigid polyurethane were investigated by conducting cup foam tests with 2 major process variables such as environmental temperature and blowing agent content.

• Journal of the Korean Society of Safety
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• v.30 no.4
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• pp.86-91
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• 2015

The flash point is used to categorize inflammable liquids according to their relative flammability. Such a categorization is important for the safe handling, storage, and transportation of inflammable liquids. The flash point temperature of two binary liquid mixtures(n-octane+n-decane and n-octane+n-dodecane) has been measured for the entire concentration range using Seta-flash closed cup tester based on the ASTM D3278 method. The closed cup flash point temperature was estimated using the UNIFAC(Universal Functional Activity Coefficient) group contribution model. The experimentally derived flash point was also compared with the predicted flash point from the UNIFAC model. The UNIFAC model is able to estimate the flash point fairly well for n-octane+n-decane mixture and n-octane+n-dodecane mixture.

• Journal of Fisheries and Marine Sciences Education
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• v.15 no.1
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• pp.123-133
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• 2003

The present investigations were carried out for the most and fundamental elements, what is called maneuverability, stability, safety, rig, sail about the world famous race, VOLVO60 and America's cup. The results obtained are summarized as follows: First, the structure of yacht should be designed with focuse on the preparation for the preparation of collision with other yachts around, with the dumps of iceberg and also whales nearby. At the same time, the accurate calculation on the each structure and equipment of yacht should be processed for the dynamic stability in the rainstorms. Second, VOLVO60, long-distance sailing, should be emphasized on the light weight and the safety, while the boat for America's cup, short-distance sailing, should be stressed on the appropriate weight of the body and the maximum speed for fast maneuverability. Third, up-to-the minute materials should be developed for the appropriate wind power and the turning of directions.

• Transactions of Materials Processing
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• v.10 no.3
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• pp.235-245
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• 2001

Deep drawing process, one of sheet metal forming methods, is very useful in the industrial field because of its efficiency The deep drawing is affected by many process variables, such as blank shapes, shape radii of the punch and die, formability of materials and so on. Especially, blank shape is very important formability factor. In this study, in order to investigate the effects of blank shape, we suggested three kinds of blank shapes and examined friction test about three conditions. We measured punch load distribution according to punch stroke under the conditions of each punch and die shape radii and observed punch load of elliptical cup forming.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.385-388
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• 2000

During the deep drawing process an initially flat blank is clamped between the die and the blank holder after which the punch moves down to deform the clamped blank into the desired shape. In general, sheet metal forming may involve stretching, drawing, bending or various combinations of those basic modes of deformation. The deformation problems of sheet metal working involve non-linearity in geometry and material. In this work, The punch load and thickness strain of electro-galvanized sheet steel (SECD) for elliptical deep drawing are examined under the various process conditions including, punch shape radius, die shape radius. The changes of punch load and thickness strain distribution of the deformed elliptical cup are affected by the size of each die shape radius.

• Transactions of Materials Processing
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• v.18 no.3
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• pp.256-261
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• 2009

Polyurethane has been one of the most important materials for automobile elastic parts such as bumper, head rest, instrument panel and so on since it covers very wide range of mechanical characteristics with low production costs. The processing variables such as formulation of ingredients and mold temperature, mixing speed, etc. can affect the quality of produced polyurethane foams so that process conditions should be determined appropriately. In this study, foaming behaviors of semi-rigid polyurethane were investigated by conducting cup foam tests with two major processing variables such as environmental temperature and blowing agent content. In addition, it was verified that processing conditions of real practice can be determined effectively by considering foaming characteristics obtained by the cup foam tests.

• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.1
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• pp.190-198
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• 1989

Some Developments in computer aided procedures for cold forging process and tool design of rotationally symmetric cup shape parts are described. The developed system enables appropriate forging sequence to be determined automatically, together with details of corresponding preform, die and punch design. The computer program developed is interactive and written in BASIC. This system not only assist the heavy work of designers but greatly shorten the time of design.

• Transactions of Materials Processing
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• v.6 no.5
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• pp.416-424
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• 1997

In the present study, a contact search and check algorithm for general tool surface described by triangular FE patch is proposed. To improve numerical stability, SEAM element using the linear Coons interpolation has been used. To check the proposed algorithm, both clover cup and L-shape cup deep drawing processes are calculated. The computed results shows that the proposed contact algorithm can be successfully applied for sheet metal forming processes with general shaped tools.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1997.10a
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• pp.176-181
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• 1997

During a compression molding of continuous fiber reinforced composites, the separation of matrix and fiber is caused by the flow of the molding process. As the characteristics of the products are greatly dependent on the separation, it is very important to clarify the separation in relation to molding condition, degree of needle punching number on the degree of nonhomogeneity are studied.

• Journal of the Korean Society of Clothing and Textiles
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• v.36 no.8
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• pp.791-801
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• 2012

We performed an assessment of wearing, purchasing, satisfaction, and the fit of brassieres according to body and breast type for college women to provide basic data on the manufacture of an ergonomic brassiere. The classifications of domed and conical breast type or projecting and conical breast type were unclear. Flat breast were dissatisfied with the shape of small and flat, and drooping breast were dissatisfied with the shape of big, projected, and drooping. In purchasing a brassiere, the majority of subjects were ignorant of their brassiere size, and over 80% of the subjects bought a brassiere without trying it on. Over 50% of those surveyed said they found it difficult to buy a well-fitted brassiere, particularly for the flat and drooping breast type. Over 70% of those surveyed wore a brassiere of 3/4 cup size, the slim body type wore a brassiere of 1/2 cup size; however, the obese body type wore a brassiere of full-cup size. The flat-breast or slim-body wore a brassiere of a thick pad type but projecting-breast or drooping breast wore brassiere of a thin pad type. Many of the subjects wore an unfitted brassiere in cup size and under bust size. In the classification of breast type, there were slight differences between the breast type that they recognized and the breast type that they were shown. There were distinctions in function, satisfaction, and fitness based on breast type. Therefore, the development of an ergonomic brassiere should considered the characteristics of breast type for fitness and comfort.