• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 추계학술대회논문집
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• pp.152-155
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• 2003

In order to examine the springback of aluminum alloy sheets, AL1050 and AL5052, in the warm forming which forms the sheet above room temperature, the stretch bending and draw bending tests in various working temperatures were carried out. While the springbacks of AL5052 and AL1050 are tremendously reduced over 150$^{\circ}C$ in the stretch bending test, the springbacks in the draw bending test are rapidly reduced in 150$^{\circ}C$-200$^{\circ}C$ for AL5052 and 200$^{\circ}C$-250$^{\circ}C$ for AL1050. Using the FEM program, the forming and springback processes are analyzed. Though springback amounts of analysis result are slightly bigger than those of experiment, they showed the same trend in the decreasing springback as the forming temperature increases.

• 소성∙가공
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• 제12권3호
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• pp.202-207
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• 2003

In order to examine the springback amount and material properties of aluminum alloy sheets (AL1050 and AL5052) in the warm forming which forms the sheet above the room temperature, the stretch bending and draw bending tests and tensile test in various high temperatures are carried out. The warm forming temperature 15$0^{\circ}C$ is a transition in terms of the material properties: over the forming temperature 15$0^{\circ}C$, them $\sigma$$_{YS}$ , $\sigma$$_{TS}$ , E, K, n, etc. are bigger but $\varepsilon$ and plastic strain ratio are smaller. Below the forming temperature 15$0^{\circ}C$, there are no big differences in material properties as the forming temperature changes. AL5052 sheet has more springback effect than AL1050 sheet. While the springbacks of AL5052 and AL1050 sheets show a big reduction over the warm forming temperature 15$0^{\circ}C$ in the stretch bending test, the springback rapidly reduces in the warm forming temperature 15$0^{\circ}C$-20$0^{\circ}C$ for AL5052 sheet and 20$0^{\circ}C$-25$0^{\circ}C$ for AL1050 sheet in the draw bending test.

• 소성∙가공
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• 제32권2호
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• pp.61-66
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• 2023

The quality of the sheared surface affects the stretch flangeability of steel sheet. The quality of sheared surface is influenced by several process factors such as die clearance, shape of cutting edge, use of counter punch, and shear. In this paper, the influence of these shearing process factors on the stretch flangeability of the HSS (DP980) was analyzed through a shearing and a stretch flangeability test. When the die clearance was 10%, the effect of these shearing process factors on the stretch flangeability was the greatest, and the use of an acute angle blade was found to be more advantageous in the stretch flangeability than a right angle blade. It was found that the stretch flangeability was improved when active bending was applied during shearing.

• 한국전문물리치료학회지
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• 제26권3호
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• pp.32-41
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• 2019

Background: Limitations in hip flexion caused by tight hamstrings lead to excessive lumbar flexion and low back pain. Accordingly, many studies have examined how to stretch the hamstring muscle. However, no study has focused on the effect of hamstring eccentric exercise for tight hamstrings on trunk forward bending. Objects: We compared the short-term effect of hamstring eccentric exercise (HEE) and hamstring static stretching (HSS) on trunk forward bending in individuals with tight hamstrings. Methods: Thirty individuals with tight hamstrings participated in the study. The subjects were randomly allocated to either a HEE or HSS group. To determine whether the hamstrings were tight, the active knee extension (AKE) test was performed, and the degree of hip flexion was measured. To assess trunk forward bending, subjects performed the fingertip to floor (FTF) and modified modified Schober tests, and the degree of trunk forward bending was measured using an inclinometer. We used paired t-tests to compare the values before and after exercise in each group and independent t-tests to compare the two groups on various measures Results: The FTF test results were improved significantly after the exercise in both groups, and AKE for both legs increased significantly in both groups. There was no significant difference in the hip angles, mmS test results, or degree of trunk forward bending between groups after the exercise. No test results differed significantly between the two groups at baseline or after the exercise. Both groups increased hamstring flexibility and trunk forward bending. Conclusion: HSS and the HEE groups increased hamstring flexibility and trunk forward bending. However, HEE has additional benefits, such as injury prevention and muscle strengthening.

• 한국의상디자인학회지
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• 제9권3호
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• pp.191-203
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• 2007

The purpose of this study was to present a making method of jeans pattern with high fitness after deriving the appropriate shrinkage rate by material and washing process. According to the result of the exterior evaluation of test jeans, all 6 jeans were rated high with scores close to 3.5. Following the evaluation of satisfaction of usage by physical movement, the highest ranking was in the order of walking with normal steps, back bending $90^{\circ}$, chair sitting, climbing stairs and squatting. The shrinkage rate by physical area showed the highest score in the order of pants length, waist circumference, thigh circumference, knee circumference, hem circumference, hips circumference. In addition, the shrinkage rate was higher in warp direction than weft direction after washing finishing. As for the result of addition and reduction of pattern measurements by parts of jeans, waist circumference was $3.1{\sim}5.1cm$, hips circumference was $-1.2{\sim}4.2cm$, thigh circumference was $-0.9{\sim}3.1cm$ and pants length was $3.4{\sim}6.1cm$. That is, this results showed a wide range of addition and reduction according to material and washing finishing.

• 한국의류산업학회지
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• 제14권3호
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• pp.454-464
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• 2012

In this study, fitness tests for slacks were divided into shape fitness test and motion fitness test, and the fitness test conditions for slacks were designed as the first step for standardization of measuring scales. Shape fitness test consisted of analyzing the parameters of appearance sensory tests as described in preceding studies, performing a simulated appearance sensory test, collecting and considering apparel experts' opinions about the test parameters, and establishing test conditions in terms of test regions, descriptions and faces. For the regions of the abdomen, hip, crotch, thighs, and knees, the parameter of unnecessary wrinkle/stretch was observed from the anterior and posterior body, and then evaluated; for waist, hip, crotch, knee and hem circumference, the parameters of ease and horizontality were observed from the anterior body and posterior body followed by evaluation; and, at the levels of waist, hip, crotch, knee and hem circumference, the division of the lateral line were observed from the lateral body followed by evaluation. Motion fitness test was composed of reviewing and analyzing comparatively the methods of motion fitness tests as mentioned in preceding studies, and establishing test conditions in terms of test motions and test regions. For each of the waist, abdomen, hip, crotch, and knees, wear sensation was tested in the positions as follows: upright standing, moderate walking, chairsitting, bending forward to the maximum, and kneeling down, provided that as the measured points of garment pressure, anterior waist, abdominal protrusion, buttock protrusion, crotch, and midpatella were set and tested.

• 복식문화연구
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• 제16권3호
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• pp.461-474
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• 2008

The purpose of this study was to present a making method of jeans pattern with high fitness after deriving the appropriate shrinkage rate by material and washing process. Research Method of jeans pattern was presented after applying the optimized shrinkage rate. According to the result of the exterior evaluation of test jeans, all 6 jeans were rated high with scores close to 3.5. Following the evaluation of satisfaction of usage by physical movement, the highest ranking was in the order of walking with normal steps, back bending $90^{\circ}$, chair sitting, climbing stairs, and squatting. The shrinkage rate by physical area showed the highest score in the order of pants length, waist circumference, thigh circumference, knee circumference, hem circumference, hips circumference. In addition, the shrinkage rate was higher in warp direction than weft direction after washing finishing. As for the result of addition and reduction of pattern measurements by parts of jeans, waist circumference was $2.5{\sim}5.2cm$, hips circumference was $-1.8{\sim}2.8cm$, thigh circumference was $-1.3{\sim}2.0cm$ and knee circumference was $-1.0{\sim}1.7cm$. Also, hem circumference was $-1.0{\sim}1.8cm$ and pants length was $2.9{\sim}6.2cm$. That is, this results showed a wide range of addition and reduction according to material and washing finishing.

• 한국구조물진단유지관리공학회 논문집
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• 제22권6호
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• pp.170-175
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• 2018

내진 성능 학보를 위해서는 신축이음장치가 지진력에 대하여 적절한 변형이 발생하여 신축이음장치의 파괴를 방지하여야 하는데 최근에 국내에서 신축이음장치의 핑거부에 힌지를 설치하여 교축방향의 지진력에 대한 변위 저항성을 확보한 신제품이 개발되고 있다. 이에 본 논문에서는 가변형 핑거 조인트를 가지는 신축이음장치에 대하여 실물규모의 교축직각방향 하중에 대한 저항성을 실험적으로 평가하였다. 실험결과, 최대 수평변위는 기존 신축이음 실험체의 경우 약 21.1mm, 내진 신축이음 실험체의 경우 51.00mm로 나타났으며, 기존제품은 추가적으로 16.5mm의 솟음이 발생되었다. 기존 신축이음 실험체는 어느 정도의 교축직각 방향의 하중에 대하여 저항한 후, 핑거의 휨 및 전단 변형이 과도하게 발생되며 파단 현상이 발생할 가능성이 있을 것으로 추정된다. 반면에 내진 신축이음 실험체의 경우, 교축 직각방향의 하중에 대하여 하중에 대한 변형을 핑거의 힌지가 흡수하여 신축이음장치 및 상부구조에 응력을 발생시키지 않고 다만 하중 작용방향으로의 수평 변형만 발생시킬 것으로 예상된다.

• 한국의류학회지
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• 제34권1호
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• pp.50-66
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• 2010

This Shanghai region study is a sample survey of female college students in their early 20s. This study collected and analyzed the information of shapes through a direct contact survey to understand the breast figures and the measurements of bodies to provide basic information to improve brassiere production for adult females in China. Data was analyzed through a SAS 9.0. The characteristic of the final brassiere pattern that had been corrected and complemented from the results of the $l^{st},\;2^{nd},\;3^{rd}$, and $4^{th}$ fitting tests is defined as a brassiere inserted with a round wire that has the 3/4cup to wrap the bust area by about 3/4. It consists of an upper and lower nonwoven fabric cup that has a flat-shaped wing of a circular dart. The drawing method of the pattern of this brassiere is applied with the conditions to cover the body naturally under the diverse and organic relations of the material factor of stretch material and wire, functional factor, and sewing factor. The final pattern is created as a bigger angle of wing pattern and a short inner side diameter because there are more Chinese women with a back of bending figure compared to Korean women.