• The Bulletin of The Korean Astronomical Society
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• v.40 no.2
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• pp.40.1-40.1
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• 2015

Off-axis reflective optical systems have attractive advantages relative to their on-axis or refractive counterparts, for example, zero chromatic aberration, no obstruction, and a wide field of view. For the efficient operation of off-axis reflective system, the surface accuracy of freeform mirrors should be higher than the order of wavelengths at which the reflective optical systems operate. Especially for applications in shorter wavelength regions, such as visible and ultraviolet, higher surface accuracy of freeform mirrors is required to minimize the light scattering. In this work, we propose the error compensation algorithm (ECA) for the correction of wavefront errors on freeform mirrors. The ECA converts a form error pattern into polynomial expression by fitting a least square method. The error pattern is measured by using an ultra-high accurate 3-D profilometer (UA3P, Panasonic Corp.). The measured data are fitted by two fitting models: Sag (Delta Z) data model and form (Z) data model. To evaluate fitting accuracy of these models, we compared the fitted error patterns with the measured error pattern.

• Fashion & Textile Research Journal
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• v.19 no.5
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• pp.635-645
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• 2017

The industry of character toys is increasing and new characters are constantly being developed. However, the development of 2D cover patterns for toys is time-consuming due to frequent pattern modifications made through trial and error. Studies are now underway to obtain 2D clothing patterns from 3D body data, however, little research has been done on 2D pattern of character toys. This study suggests efficient guidelines to develop 2D cover patterns with a reasonable accuracy and processing time. Two 3D models of a dog and rabbit were used to develop 2D cover patterns. Independent variables of this study are set as 3 levels of triangle area (small, medium, and large) that influence the efficacy of 3D and 2D pattern development. The determination of the appropriate triangular area was based on the area and shape change of the 2D pattern. A medium or large triangle area was shown to be suitable for a character dog with a smooth curved surface. However, the appropriate triangle area was small if the characteristics of the curved surface are complicated as in the case of rabbit. The head of a dog (a double-curved surface) and the curved forepaw of a rabbit (a triangular area) should be small when the characteristics of the curved surface (such as the hind leg of a rabbit having a large convex surface and a small surface area) are complicated. Grouping by 3D surface characteristics could be a suitable guideline for the triangle area selection.

• The Korean Journal of Community Living Science
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• v.28 no.4
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• pp.505-514
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• 2017

Although studies on the development of cool touch fabrics have been conducted widely, the effects of fitted pattern on enhancing the cooling sensation are insufficient. To investigate the effect of cool-touch fabric and fit of women's sports underwear, 3D and 2D patterns of sleeveless top and sports leggings were constructed. The performance of cool touch was tested by the Qmax value and wear test with nine subjects. Objective fit evaluation was observed by 3D virtual clothing using Clo software. Subjects rated wearing sensation such as 'cooling sensation, fit, wear comfort and preferences of purchase' using Likert's scale in the environmental chamber at $25^{\circ}C$, 45 %RH. The Qmax value of the cool touch fabric was higher than that of the PET fabric, which was well reflected in 'cooling sensation', especially in the case of a tight-fitted 3D pattern. The cooling sensation of the cool-touch fabric was not significantly elevated with 3D tight pattern as long as the size of the 2D pattern was similar to that of 3D pattern. However, the purchase preference was highly correlated with 3D fit and wear comfort.

• Korean Journal of Radiology
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• v.22 no.7
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• pp.1194-1202
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• 2021

Objective: To investigate the age-dependent changes in regional cerebral blood flow (CBF) in healthy adults by fitting mathematical models to imaging data. Materials and Methods: In this prospective study, 90 healthy adults underwent pseudo-continuous arterial spin labeling imaging of the brain. Regional CBF values were extracted from the arterial spin labeling images of each subject. Multivariable regression with the Akaike information criterion, link test, and F test (Ramsey's regression equation specification error test) was performed for 7 models in every brain region to determine the best mathematical model for fitting the relationship between CBF and age. Results: Of all 87 brain regions, 68 brain regions were best fitted by cubic models, 9 brain regions were best fitted by quadratic models, and 10 brain regions were best fitted by linear models. In most brain regions (global gray matter and the other 65 brain regions), CBF decreased nonlinearly with aging, and the rate of CBF reduction decreased with aging, gradually approaching 0 after approximately 60. CBF in some regions of the frontal, parietal, and occipital lobes increased nonlinearly with aging before age 30, approximately, and decreased nonlinearly with aging for the rest of life. Conclusion: In adults, the age-related perfusion patterns in most brain regions were best fitted by the cubic models, and age-dependent CBF changes were nonlinear.

• Journal of Ocean Engineering and Technology
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• v.6 no.2
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• pp.143-150
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• 1992

Numerical simulation is made of a stably stratified salt-water solution due to lateral heating in an equilateral trapezoidal enclosure using boundary-fitted coordinate in grid generation. Results show four types of the global fluid pattern depending on the buoyancy ratio in the enclosure, i.e., unicell flow pattern for the low buoyancy ratio, layered flow pattern for the increasing buoyancy ratio, layered flow pattern with stagnant zone for the relatively high buoyancy ratio and stagnant flow pattern for the much higher buoyancy ratio.

• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.7 s.144
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• pp.1008-1017
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• 2005

When we develop 2D pattern from replica of human body with small pieces, it is inevitable to have some replica pieces overlapped or departed. In this study, the optimized method of 2D pattern development from the 3D replica pieces was investigated using dress-form. Among six arrangement methods, anchoring two vertexes of a replica to neighboring vertexes of a next replica induces the optimized 2D pattern by evenly distributing stress across the 3D replica pieces. Anchoring neighboring vertexes resulted in automatic widening k overlapping (W & O) the interspaces among replicas of dress-form, thereby stress was distributed more evenly than any other method. W&O arrangement method was verified to be the best by examining the 3D space distribution images between body surface and twelve experimental garments.

• Journal of the Korean Home Economics Association
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• v.40 no.10
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• pp.177-189
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• 2002

The purpose of this study was to develop a suitable jacket pattern for elderly women. The subjects were two women of the ages of 65-70, who had different bust size. To reflect the ready made pattern drafting systems, 4 industrial patterns were selected. After analyzing the problems of these patterns, a new jacket pattern was proposed. The results were as follows : 1) The amount of appropriate ease in fitted jacket for elderly women was about 10cm at the bust circumference, 10∼12cm at the hip circumference and the height of sleeve cap was AH/3+0.5cm. 2) Considering an enlargement of waist and abdomen, difference between front and back size was 2cm on the bust line, 6-8cm on the waist and hip line. 3) Because of the shape of concavity of back-waist, center back line in the pattern was folded by 0.5cm from center back waist toward side seam for manipulation. 4) The new jacket pattern was compared with the existing pattern through the wearing test by sensory evaluation. It showed that the fit and comfort of experimental pattern was superior to those of the existing pattern.

• Journal of the Korean Home Economics Association
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• v.44 no.7 s.221
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• pp.153-162
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• 2006

This study was attempted to investigate the possibilities of fitness evaluation of virtual model using 3D clothes modeling software. For the purpose, two one-piece dresses were made with two kinds of patterns using Qualoth program, and then each dress was fitted to a real model and a virtual model, and the results were compared and discussed. The result of this study was as follows. First, the fitness evaluation of real model showed a significant difference only at a little difference in figures (1-2.5cm) of the pattern, while any significant difference in appearance was not found in case of a virtual model fitted a dress made out of a pattern with the same difference in figures. Second, items to evaluate a difference in patterns using 3D clothes modeling software were shoulder line, the distance between shoulder points, armhole line, ease of armscye depth, and overall appearance. Because all the items fall under design lines which make up outer lines of a cloth, it can be said that the Qualoth program is good for representing design, rather than exposing a small difference in patterns.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.167.1-167.1
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• 2015

We investigate the degradation pattern of Black phosphorus (BP) field effect transistor (FETs) was investigated by using an mechanically exfoliated BP that react O2 and water vapor in ambient condition, degradation. The BP FETs was electrically measured every 20 minutes (1cycle) in the air, the total cycle is 100. We show electrical changes with Mobility, On/off ratio, Current and a significant positive shift in the threshold voltage. We extracted the current level at Vgs-Vth = 0, -10, -20 and fitting with Swiss-cheese model. This model suggested that Swiss-cheese model is well fitted with degradation pattern of BP FETs.

• Journal of the Ergonomics Society of Korea
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• v.12 no.1
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• pp.39-55
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• 1993

The purpose of this study was to develop a basic slacks pattern drafting me- thod for pregnant women on the basic of their physicial characteristics. The results of the study were as follows: 1. The items which showed a remakable and significant increase were anterior waist height, waist depth, omphalion depth, abdominal depth, waist girth, omphalion girth, abdominal girth and body weight. The anterior part of waist and abdominal sections projected forward gradually, so remarkably as to become to look like a circle, at ten month. 2. Sensory evaluation for Appearance: According to the statistical analysis of the result of 25 items on the questionnaire, all the items showed significant difference$({\alpha}{\leq} 0.001)$ between the new and the MUNHWA method slacks pattern, with the new pattern having having higher scores. 3. Sensory evaluation for Comfort : The new drafting method proved to be better fitted and more comfortable.