• Journal of the Korean Society for Heat Treatment
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• v.18 no.2
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• pp.105-111
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• 2005

In sheet metal forming, drawbeads are often used to control uneven material flow, which may cause defects such as wrinkles, fractures, surface distortion and springback. Appropriate setting and adjusting of the drawbead force is one of the most important parameters in sheet forming process control. Therefore in this study, drawbead test was performed at various bead surface treatment conditions to clarify the frictional characteristics between sheet and drawbead. Furthermore, the differences in drawing force between circular and rectangular shape beads have also been measured to estimate the effectiveness of bead shape on the material flow control. The results show that drawing and friction characteristic were strongly influenced by surface treatments of bead and bead shapes.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.2
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• pp.248-258
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• 1992

Three-dimensional rigid-plastic finite element formulation based on the membrane theory was described and a computer program for large deformation analysis was developed. In the formulation, normal and planar anisotropy of sheet material and rotation of the principal axes of anisotropy was taken into consideration. Sheet metal was assumed to be rigid-plastic material obeying Hill's quadratic yield criterion and its associated flow rule. Deep drawing process, as a preliminary test, for normal anisotropic material was analyzed in order to examine the validity of developed finite element program. The results were consistent with the existing finite element solutions or experimental data. The present study was mainly concerned with the influence of planar anisotropy on deformation behaviour. Finite element analysis and experiment were carried out for the whole process of deep drawing of planar anisotropic material. The computational and experimental results on the shape of ear, strain distribution and punch load were in good agreement.

• Journal of the Korean Society of Physical Medicine
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• v.8 no.2
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• pp.231-238
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• 2013

PURPOSE: The purpose of this study is to find out the thickness variation of the superficial and deep abdominal muscles by measuring the thickness of the abdominal muscles. METHODS: 35 young, healthy adults(24 mens and 11 womens) participated in this study. The first, when only bridge exercise we had measured the thickness of their abdominal muscles by the ultrasound. The second, when the abdominal drawing-in during maintaining the bridge exercise we had measured the thickness of their abdominal muscles by the ultrasound. A pared t-test was used to determine a statistical significance for the thickness variation of the superficial and deep abdominal muscles. RESULTS: Results of before and after comparative analysis. The surperficial muscles(rectus abdominis, external obilique) statistically significantly reduced in the thickness and the deep muscle(transeverse abdominis) statistically significantly increased in the thickness. CONCLUSION: We have shown that the abdominal drawing-in exercise during maintaining the bridge exercise was effective to increase in strengthening abdominal deep muscle selectively.

• The Research Journal of the Costume Culture
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• v.12 no.1
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• pp.28-40
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• 2004

The purpose of this study was (1) to identify the experimental bias which could appear person perception as results of development methods (2) to find out the most desirable method in developments of stimulus. The research was a quasi experiment and the subjects were 358 male and female undergraduate students by convenient sampling. The experimental instruments consisted of a set of stimulus and semantic differential scales of 7-point bi-polar adjectives. The collected data were analyzed by Principle Component Analysis, ANOVA(analysis of variance), Scheffe's multiple range test. The independent variables were developing methods of stimulus(live person, photography of real person, 2 kinds of black and white line drawing, 2 kinds of color drawing). The results were as follows. First, five factors which were potency, sociality, appearance, evaluation, activity impressional dimensions emerged to account for the methods of development of stimulus. Second, the methods of development of stimulus had significant effects on potency, sociality, appearance, activity factors. In sociality factors, the impression of photographic stimulus was the closest to the live person's impression. However in the appearance and activity impressions, significant difference existed between live person and other developing stimulus. In the potency impression, black and white line-drawing gave the highest impressional bias. In the sociability and appearance impressions, color-drawing stimulus gave the highest impressional bias. Result: On conclusion the developments of stimulus can effect on stimulus person's impressions and these effects can produce experimental biases, the photographic stimulus gave the least impressional bias. The study shows that photography of real person will produce minimize measurement error.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.6
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• pp.1961-1968
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• 2010

The Face Stimulus Assessment is an efficient projective drawing test developed by Betts. This paper categorizes scales which Betts suggested into the following five groups: accuracy of painting, color fit, perception of shape, precision of drawing, and space usage. In this paper, a computer algorithm which objectively evaluates these five scales is suggested. The proposed algorithm defines the areas of the lip, eyes, hair, etc. which take on significant roles in the evaluation of the FSA and based on these factors, it calculates the grade of each scale through the main color and color ratio. The consistency of evaluations between the computer algorithm and the art therapist is measured by the Quadratic Weighted Kappa. By providing objectivity and consistency, the computer algorithm is expected to solve the problem of uncertainty found in art therapists' evaluations of projective drawing tests caused by their subjective judgment, experience, and intuition.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.10a
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• pp.250-253
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• 2009

In this study, the friction test was performed to find friction characteristics of advanced high strength steel (AHSS) sheets and the multiple regression method was employed to obtain friction models. The friction coefficients associated with the lubricant viscosity, drawing speed, and blank holding pressure are measured. Differently from GA steel sheets, the effects of the lubricant viscosity and pulling speed are a little, which are explained by a theory of adhesion and wear as well as a deformation of friction surface. In addition, the effects of friction parameters are numerically represented by friction regression models.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.191-194
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• 2006

Recently the quality improvement of the steel cord product is demanded by the tire market. After wire drawing process, produced residual stresses have a harmful effect on the durability of the wire and become the cause which decreases the quality of the product. Therefore, to improve the quality of the steel cord product, the research regarding the method of residual stress relaxation is necessary. To evaluate the quality of the drawn wire, it is important to measure the residual stress, because the residual stress decides a variety of the quality level which is demanded in the drawn wire. This study proposed a residual stress relaxation method in the drawn wire using FE analysis. The validity of the analysis results was verified by nanoindentation test.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1997.03a
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• pp.19-24
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• 1997

The weld line location and the weld line movement in stamping with laser-tailor welded blanks(TWB) were investigated through square cup deep drawing tests. The step blank holder was introduced to form TWB of different thicknesses without wrinkling, and the non-uniform blank holding force(BHF) was enforced to control weld line movement. Test results of the blanks with shifted weld lines showed that the large portion of the thinner area could result in a large weld line movement. Careful selection of the weld line location and the BHF control should be adapted in TWB design to avoid failures and to ensure its formability.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.08a
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• pp.91-97
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• 2004

The drawbead is one of the most important factors in sheet metal forming for automotive parts. So clarifying the friction characteristics between sheets and drawbead is essential to improve the formability of sheet metal. Therefore in this study, drawbead friction test was performed at various bead materials(FC300, HC891, FCD550, HD700, HK600, HK700, SKD11) and surface treatment of beads(Base, induction hardening, Cr plating, ion nitriding, Toyoda diffusion process, TiCN, TiN, CrN). Circular shape bead has been used for the test. The results show that friction and drawing characteristics were mainly influenced by surface treatment.

• Korean Journal of Child Studies
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• v.22 no.2
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• pp.347-360
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• 2001

In order to analyze the human figure drawings of children with emotional and behavioural problems, the Preschool Behaviour Checklist (McGuire & Richman, 1988) was administered to 300 6-year-old children from which 15 boys and 15 girls with emotional and behavioural problems and 15 boys and 15 girls without problems were selected for the target and comparison groups, respectively. Compared with children without emotional and behavioural problems, the human figure drawings of the disturbed children included immature eye drawings; immature liaison of body and arms or legs; no hair; strong and repeated lines; unbalanced arms and legs; unbalanced size of face, body, arms, and legs; and the size of the human figure less than a fifth of the sheet of paper. These results imply that the human figure drawing test is an efficient way to screen children's emotional and behavioural problems.