• Transactions of Materials Processing
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• v.14 no.6 s.78
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• pp.533-540
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• 2005

The hemming process, composed of flanging, pre-hemming and main hemming, is the last one of a series of forming processes conducted on the automotive panels, having greater influence on the outward appearance of cars rather than on their performance. The hem quality can be quantitatively defined by the hemming defects including turn-down/up, warp and roll-in/out. However, it is difficult to evaluate and predict the hem quality through an experimental measurement or a numerical calculation since the size of defects is very small. This study aims to precisely evaluate the hemming defects, especially turn-down and roll-in, through numerical and experimental approaches and to investigate the influence of process parameters on the hem quality, focused on how to simulate the same conditions as in the experiment by the finite element analysis (FEA). The FEA results on the turn-down and roll-in obtained from a model composed of the optimum-sized elements, including a spring element linked to the flanging pad, and given the double master contact condition between the inner and outer panels, had a good correlation with the experimental data. It is thought possible to make an early estimate of the hem quality in a practical automotive design by applying the methodology proposed in this study.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10a
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• pp.113-116
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• 2003

Hem quality can be determined mainly by turn-down and roll-in. Turn-down, that is created by the elastic recovery, can't be easily detected and measured since it is usually as small as 0.03 m. This study is focused on the precise evaluation of the hemming defects through analytical and experimetal approaches, and on the investigation of the influence of process parameters on the final hem quality. Implicit finite element analysis of plane-strain hemming process is performed by using a commercial code ABAQUS/Standard. Experiment and measurement is also carried out for steel and aluminium sheet metals, and the results are compared with those of analysis.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.05a
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• pp.101-105
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• 2005

Hemming process, composed of flanging, pre-hemming and main hemming, is the last one of a series of forming processes conducted on the automotive panels, having a great influence on the outward appearance of them. The hem quality can be quantitatively defined by the hemming defects including turn-down, warp and roll-in. However, it is difficult to evaluate and predict the hem quality through the experimental measurement or the numerical calculation since the size of defects is very small. This study is focused on how to simulate in the finite element analysis (FEA) the same conditions as in the experiment. The FEA result on turn-down, that was obtained from a finite element model including the spring element linked to the flanging pad, had a good correlation with the experimental data. It was found that the radius of curvature of the flange deeply affects the final hem quality and therefore high rigidity of forming tools and tight assembling tolerance are highly recommended. An over-stroke of the main hemming punch is also proposed to reduce the turn-down.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.983-983
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• 2012

EFDC의 수질모형인 HEM3D는 국내 해양수질모델링에는 적용된 사례가 많지만 담수에 적용된 사례는 거의 없으며, 우리나라 환경부 수질측정항목과 수질 INPUT 자료가 달라서 모델의 적용이 힘들었다. 그러나 HEM3D는 EFDC 수리모델을 연계하는 WASP에 비해 자체 3차원 수리동역학 모델이 있어 셀 개수의 제한이 없고 계산속도 또한 WASP 보다 2~3배 빠른 것으로 알려져 있다. 그러나 현재 우리나라의 수질측정항목은 HEM3D의 수질모의항목과 다소 차이가 있다. 특히 Carbon계열에서 실측수질항목은 BOD, COD인 반면 HEM3D의 모의가능항목은 RPOC, LPOC, DOC, COD로 바로 적용을 하기는 어렵다고 판단하였다. 따라서 환경부 수질자료를 HEM3D에 적용하기위해 문헌자료를 참고한 수질항목간의 분율을 사용하여 필요한 자료를 산출하였고, 환경부 수질자료의 HEM3D적용 결과를 알아보고 현재 자료 사용 시의 문제점과 향후 개선방안을 알아보고자 하였다. HEM3D의 모의 결과 TN, TP 보정에는 큰 문제가 없었으나 $BOD_5$와 세부수질항목의 영향을 많이 받는 조류 등의 항목 보정결과는 성공적이지 못했다. 이것은 분율을 적용해 각 유입지천의 세부항목별 수질 자료를 산출할 때 낙동강 전체 평균을 사용했기 때문에 조류성장에 직접적으로 영향을 받는 세부 항목별 영양염에 대한 실제 값과 산출된 농도 값 사이의 오차가 가장 큰 원인으로 판단된다. 한편 전체 대상지역중 일부구간에 대하여 동일한 수질입력자료를 이용하여 HEM3D와 WASP을 동시 적용하였다. 자료의 변환과정에서의 오차와 입력형태 및 각 모델 변수형태의 차이 등의 한계로 결과값에 차이가 있는 것으로 나타났으며, 본 연구결과 현재 확보된 수질측정망의 수질자료를 이용하여 HEM3D를 구축하는 것은 Carbon 계열과 조류(부영양화)모의에서 문제가 발생할 것으로 판단되며 추가 자료 확보가 필요할 것으로 보인다. 또한 필요한 입력자료가 충분히 확보가 된다면 추가연구결과에서 볼 수 있듯이 미국공변단과 미국 환경부수질모델 모두 동시적용이 가능하다고 판단되며 목적과 편의에 따라 선택적 모의가 가능하다고 판단된다.

• Korean Journal of Biological Psychiatry
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• v.18 no.3
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• pp.148-158
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• 2011

Objectives The eye movement (EM) has been reported to play a role in enhancing the retrieval of episodic memories and reducing effects of fearful episodes in the past and worries for the futures. However, it is still unclear in the mechanism of EM in normal subjects. We examined the horizontal eye movement (HEM) effect using an aiding apparatus on mental health indices including negative and positive psychological factors, and psychophysiological measures such as heart rate variability and quantitative electroencepaholography (qEEG) in healthy subjects. Methods Twenty eight healthy subjects were recruited and randomly allocated into two groups : active HEM group and control group. The active HEM group conducted the HEM training with usual stress management audio-intervention using the apparatus inducing eye movement once a day for 14 days. The control group also conducted the same training once a day for 14 days, however, the saccadic eye movement was not included in this training. Psychological measurements, neurocognitive function tests, heart rate variability measurement and qEEG were conducted before and after the training in both groups. Results In the active HEM group, sleep status using Sleep Quality Scale (SQS) positive factors significantly increased after the training. By contrast, scores on the negative items of Psychological Well-Being Scale (PWBS), and negative items of the Life Orientation Test-Revised (LOT-R) were significantly decreased after the training. The percentage of delta amplitude (1-3 Hz) in qEEG significantly decreased after the HEM training. The percentage of alpha amplitude (8-12 Hz) significantly increased after HEM training. The change of delta amplitude in the active HEM group was positively correlated with the change of sleep satisfaction of Visual Analogue Scale (VAS), and the change of alpha amplitude was negatively correlated with depression of VAS, anxiety of VAS and Beck Anxiety Inventory (BAI). Conclusions The HEM training improved sleep quality and well-being, and sense of optimism. The HEM training also increased alpha amplitude and decreased delta amplitude in qEEG. The qEEG changes were well correlated with subjective improvement of mental health indices in healthy subjects. These results suggest some evidences that HEM training using the apparatus that induces EM would be helpful in improving subjective mental health in healthy subjects. Further study with larger samples size would be needed.

• Journal of Fashion Business
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• v.20 no.3
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• pp.43-53
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• 2016

As the quality of life has improved with development of science and technology, desire for better quality of life of disable people has also increased. Currently, prejudiced views of disabled people in South Korea are changing, but sports for all disabled people is not revitalized and social support is also inadequate. In developed countries, administration and systems for sports among people with disabilities are provided at the consumer level, and many companies willingly provide support to disabled athletes. However, in South Korea, low awareness of sports for disabled people is companied by minimal support companies. In order for South Korea to advance, support for the disable sports players is needed, especially sports-wear that fits their body conditions and differences game playing from ordinary sports players. This study specifically focused on the ice sledge hockey players, taking into account the complaints on their jersey and their special conditions through motion analysis while sleds. For the easy use of the hockey, armhole depth and sleeve breadth was reduced and sleeve hem was designed for flexibility of sleeve such that it does not slide down. Also, because only the front of the Jersey is tucked in the pants, the side vent was designed to be deep such that the back hem is prevented from being pulled. Sportswear pattern making for the players with disabilities required to account for distinct body characteristics, as compared to the ordinary players. Thus, studies that develops sports-wear design for those with disabilities contributes to the qualitative development of sports for people with disabilities.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.17 no.31
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• pp.163-176
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• 1994

Over the last few years Total Quality Management (TQM) programs have hem widely adapted by Korean manufacturing firms to improve their productivity, competitive edge and product quality levels. The purpose of this study is to evaluate the level of importance placed on four key TQM factors (customer satisfaction, strong management leadership, continuous improvement, imployee involvement and participation) used during the implementation of korean manufacturing TQM programs and to assess the effectiveness of those key factors in improving the performance of the firms. A Questionaire was developed and sent to senior managers in manufacturing organizations throughout korea. This survey asked qustions regarding 1) the firm's business environment and TQM program development 2) subcomponents of the key factors and 3) the effectiveness of the TQM program at improving the performance of the organization. The survey data were analyzed to determine the degree of correlation between each of the factors and the effectiveness of the TQM programs. This study demonstrated that the TQM programs were instrumental at improving the performance of the firms studied, and that the improvement was positively correlated with the length of time that the program had been implemented and the planned duration of the TQM program implementation. It was found that the person-oriented elements of management leadership and employee involvement were positively correlated and predictive of the success of the TQM Program, while the process-oriented components of customer satisfaction and employee involvement were not useful predictors of the effectiveness of the TQM program implementation.

• Journal of the Korean Society of Costume
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• v.60 no.8
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• pp.67-85
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• 2010

School uniform has improved greatly in terms of fit, size, function, and design due to steep competition in the market and the strong interest of researcher, while little effort has been made for physical training uniform, so the objective of this study is to provide basic research data of the training uniform for the improvement of its design and fitness. For this purpose, 327 high school girls provided information on size and design of their uniform, level of satisfaction, the recognized ease in uniform. Most students wore the physical training uniform in another classes and the long sleeved shirt were the most popular one. They often used the uniform for the protection from cold and for comfortable activeness. For a long sleeved shirt, most students preferred raglan sleeve, zip-up collar, straight waist line, and ribbed sleeve cuffs and hem. For long pants, students preferred elastic waist band and ribbed pants cuffs. Currently, the short-sleeved shirt mostly had a shirts collar, ribbed hem, straight waist line with raglan sleeve, but students wanted a round neck and set-in sleeve. For overall level of satisfaction, students showed high satisfaction in terms of function and psychological effect, while aesthetic quality of the uniform was needed to be much improved. Most students evaluated that the circumference of uniforms properly fit or had a little ease, and students considered waist size the most suitable. The long pants length evaluated properly fit or a little long. Students accepted that the ease of summer uniform was more suitable than winter uniform's both at circumference and at length. Depending on students' height distribution, the length of long pants and short pants varied significantly.

• Journal of the Korea Fashion and Costume Design Association
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• v.6 no.3
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• pp.169-183
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• 2004

This study attempts to understand women's underwear culture in the Later Chosun Dynasty, by investigating the kinds and constructions of them, which formed bulky and puffed silhouette of the lower half of the body. In the middle 17th century in Chosun, Confucianism settled down as fundamental idea of society, while whole country achieved considerable economic growth. As a result for upperclass women, female virtues was demanded more than any other period in Chosun. On the other hand, lower-class women including Kisaengs, had more freedom on their clothing behaviors. According to the literature on women's dress institutions and restrictions of the extravagance, the use of kinds of high-quality silk and false hair was criticized, compared to women's clothes in China. From this, one can see the luxury and affluence of women's clothes at that time, which also reflected in luxurious underclothes. Also, the movement of class, by economic development, led to changes in the costumes of middle-to-lower class women, relaxing restrictions on clothes. Underclothes included Bosomband(가슴띠; long sashes for bosom to wrap), Sokjucksam(속적삼), and Sokchogori(속저고리; Korean blouse, worn under the chogori) for upper garment, and Darisokkok(다리속곳; basic underwear like the panty), Soksokkot(속속곳; underwear paji to be wide of hem), Sokpaji(속바지;trouser front and back opening), Tansokkok(단속곳; large size underwear like Soksokkot), Noronpaji(너른바지; paji like the skirt or paji bulky than tansokkot,), Mujigi무지기; tiered skirt for underwear), and Daeshumchi'ma(대슘치마; Korean underskirt, shape hem as a pad into form) for lower clothes.

• Journal of the Korean Society of Clothing and Textiles
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• v.15 no.1
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• pp.38-47
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• 1991

The purpose of this study was to investigate the effect of physical properties and grain line of fabrics on the drape properties of the flare skirt. Horizontal section overlap map was obtained by three dimensional Moire Topography, It was concluded drapability of the skirt obtained by the map can be used to determine the ease of the skirt. Grain line such as bias and lengthwise direction showed the difference of quality of the drape at the hem line; skirt made by bias direction showed evenly distributed flare and effective for the aesthetic point view. No difference was observed between cotton and polyester fabrics probably due to the similar characteristics of the fabrics.