• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2000.10a
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• pp.124-127
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• 2000

The finite element analyses of the wrinkling initiation and growth in the sheet metal forming process provide the detailed information about the wrinkling behavior of sheet metal. The direct analyses of the wrinkling initiation and growth, however, bring about a little difficulty in complex industrial problems because it needs large memory size and long computation time. For the description of wrinkling growth, the mesh elements should be sufficiently small and the size of finite element matrix becomes large. In the static implicit finite element method therefore, the direct analysis of wrinkling growth in a complex sheet metal forming process is rather difficult. From the industrial viewpoint of tooling design, the readily available information of possibility and location of wrinkling is sometimes more preferable to the detailed time-consuming information. In the present study, therefore, the wrinkling factor that shows locations and relative possibility of wrinkling initiation is proposed as a convenient tool of relative wrinkling estimation based on the energy criterion. The location and relative possibility of wrinkling initiation are predicted by calculating the wrinkling factor in various sheet metal forming processes such as cylindrical cup deep drawing, spherical cup deep drawing, and elliptical cup deep drawing. The wrinkling factor is also implemented in the analysis of the door inner stamping process to predict wrinkling.

• Journal of the Korean Society of Clothing and Textiles
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• v.48 no.4
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• pp.632-656
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• 2024

This study presents a pattern drafting method for designing a slim-fit blouse for women in their twenties with a D cup bra size and various bust sizes within the standard body type range using the 3D virtual clothing system. Three participants were scanned using a body scanner, and three similar princess blouse patterns were selected. A total of nine virtual blouses were produced, with three sets made for each participant. In the initial evaluations, Pattern C received the highest score. The second pattern was designed by mending the flaws in Pattern C. However, in the eases of the front and back busts, back width and back waist were still insufficient and sleeve length was short. In the similarity evaluation between virtual and real blouses, the overall appearance was similar. Most of the corrected elements received significantly higher ratings in the third real blouse. However, the ease of the rear bust area was slightly large. In general, when drafting blouse patterns for women with large bust sizes, it is essential to increase the ease in the front bust, reduce the ease in the back bust, enlarge the waist dart, and decrease the armhole depth.

• The Research Journal of the Costume Culture
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• v.22 no.3
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• pp.440-449
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• 2014

The purpose of this study was to investigate the suitability of brassiere size and wearing habits of Korean adolescent girls. Subjects were 13 to 17 years old girls (n=282). The data was collected by anthropometric survey and qualitative questionnaire survey. Anthropometric survey measured bust and under bust girths; Qualitative questionnaire survey focused on the practice of purchasing and wearing of brassiere. Two general conclusions emerged: 1) Majority of Korean adolescent girls wore a smaller sized cup than their breast volume 2) Korean adolescent girls wore a larger sized band. These results show the need of educating Korean adolescent girls for their appropriate brassiere size and fit. The value of the brassiere that Korean adolescent girls place differed by age. While the younger adolescent girls expected their brassiere to prevent showing the breast vibration, the older adolescent girls expected their brassiere to avoid breast sagging. The older aged adolescents more valued the fit and style of the brassiere compared to the younger aged group when they purchase brassiere. The younger adolescent girls were more likely to be dissatisfied with the fit of the cup. These results reveal that the junior brassiere should be designed to fit adolescent girls' breast shape and size.

• Korean Journal of Human Ecology
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• v.18 no.5
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• pp.1093-1101
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• 2009

To provide basic data to manufacture superior brassieres, we performed a survey on the wearing and buying habits, and preference of functions and materials of brassieres for 189 women subjects in their twenties. The results of this research are as follows; Style and size are the most important in purchasing brassieres. Flat breasted and sagging breasted subjects were dissatisfied in the fit of the upper cup. 70% of the subjects were ignorant of their brassiere size. Sagging breasted subjects were less satisfied with smoothness, softness, and weight when wearing their bras in comparison with the other types. Conical type breasts were common amongst women in their 20s. They are more likely to wear size 75A and 80A where the full bust girth is 10cm larger than the under-bust. They preferred demi cup brassieres with thin or moderate padding to full cup brassieres with thick padding. On the other hand, 56.8% of subjects wore brassieres all day. The subjects were dissatisfied with the slipping down of the shoulder straps. Large-breasted subjects were concerned more with dampness and the fit on the center front of the brassiere, and brassieres with too thick padding had a poor fit on the center front. Sports-brassieres which fit close to the skin and used stretchable fabric caused more itching and dampness and dissatisfaction in removal of the brassiere.

• 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.

• Culinary science and hospitality research
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• v.13 no.2
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• pp.216-222
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• 2007

Sometimes the problem occurs that a paper knob and a thread attached to a tea bag fall into tea water in pouring tea water into a conventional cup to extract bag type tea. A new cup was developed to solve that problem, which was formed with a thread groove(dia. ; about $1.5{\sim}2\;mm$, hight ; about $4{\sim}5\;mm$) in the upper end of the cup. As a result, the new cup with a thread groove is expected that a paper knob with a thread does not fall into tea water. In addition, the size of a paper knob and the length of a thread may be reduced 70%, respectively.

• Journal of the Korean Society of Clothing and Textiles
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• v.43 no.2
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• pp.215-227
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• 2019

This study develops a post-operative brassiere suitable for changed breast shapes and the characteristics of breast augmentation patients. Six subjects who experienced breast augmentation surgery with a cup size of C or D cup participated in the wearing test. We conducted a wearing test to evaluate the superiority of the developed post-operative bra. As a result, the evaluation of the developed bra was excellent in the outer cup, outer circle of breast front gore, shoulder straps and the wing pressures. Second the satisfaction of the developed brassiere was high in the front center part, and in the evaluation of wearing satisfaction of the subjects; in addition, the degree of close contact with the cup, flexibility, touch, and overall evaluation. The satisfaction of the developed bra was also higher than a commercial bra. Third, the developed bra proved superior in the adaptability test, such as prevention of breast shaking, prevention of bra and breast separation during movements, and ease of body movement.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.05a
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• pp.235-238
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• 2001

Milli-structure components are classified as a component group whose size is between macro and micro scales, that is, about less than 20mm and larger than 1mm. The forming of these components has a typical phenomenon of bulk deformation with thin sheets because of the forming size. In this study, milli-structure rectangular cup drawing is analyzed and measured using the finite element method and experiment. Generally, milli-structure containers or cases like cellular phone vibrator consist of rectangular-shaped drawing to save installation space. A systematic approach is established for the design and the experiment of the forming processes for rectangular milli-structure cases. To verify the simulation results, the experimental investigations were also carried out on a real industrial product. The numerical analysis by FEM shows good agreement with the experimental results in view of the deformation shape of the product.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2000.10a
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• pp.101-104
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• 2000

Milli-structure components are classified as component group whose size is between macro and micro scale. that is, about less than 20mm and larger than 1mm. The forming of these components has a typical phenomenon of bulk deformation with thin sheets because of the forming size. In order to conventional metal forming, where numerical process simulation is already idly applied, the micro-forming process is characterized by some scale effects which have to be considered in an advanced process simulation. milli-structure rectangular cup drawing is analyzed and designed using the finite element method and experiment. The result of the finite element analysis is confirmed by a series of experiment.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.471-476
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• 2001

Milli-structure components ate classified as a component group whose size is between macro and micro scales, that is, about less than 20mm and larger than 1mm. The forming of these components has a typical phenomenon of bulk deformation with thin sheets because of the forming size. In this study, milli-structure rectangular cup drawing is analyzed and measured using the finite element method and experiment. Generally, milli-structure containers or cases like cellular phone vibrator consist of rectangular-shaped drawing to save installation space. A systematic approach is established for the design and the experiment of the forming processes for rectangular milli-structure cases. To verify the simulation results, the experimental investigations were also carried out on a real industrial product. The numerical analysis by FEM shows good agreement with the experimental results in view of the deformation shape of the product.