• Proceedings of the KSR Conference
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• 2002.10a
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• pp.31-37
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• 2002

Rail cars are subject to vibration, impact and wear which can cause severe defects leading to a fatal accident. Thus, they are designed and manufactured in consideration of such factors influencing their service lifetime. Under-frames are composed of steel and support most of load imposed on the car. Steel is very sensitive to corrosive environment and corroded even in a normal service condition. Regular maintenance can Protect steel Parts from corrosion by painting. However, an exposure of defect point to corrosive agents can make corrosion proceed to a considerable depth, which may cause the structure to remain under safety standard. It is necessary to understand corrosion behavior of rail cars in order to estimate unexpected accidents by corrosion.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.6
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• pp.612-623
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• 2003

The purpose of this study was to find out the effects of mother's parenting attitudes on children's clothing orientation and clothing purchase behaviors. The questionnaires for this study were distributed to 166 fifth and sixth graders of elementary schools and 166 their mothers in Seoul. The data were analyzed through chi-square test, factor analysis, cluster analysis, MANOVA, ANOVA, and LSD test. Responses were classified as 4 groups (Acceptance-Autonomy, Acceptance-Control, Rejection-Autonomy, and Rejection- Control groups) based on mother's parenting attitude. The four groups showed significant differences both in clothing orientation and clothing purchase behaviors. Especially, the Rejection-Control group, which is easily influenced by peer students, placed much emphasis on fashionability of clothing and showed strong complaining behaviors toward unsatisfactory clothing selected by their mothers. Study results suggest the importance of mother's parenting attitude on analysis of target market for children's wear.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2000.11a
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• pp.304-309
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• 2000

Si$_3$N$_4$-6wt%Y$_2$O$_3$-lwt%Al$_2$O$_3$was prepared by hot pressed and gas pressure sintering to investigate the effect of microstructure on erosion behaviors. Hardness and fracture toughness were measured with prepared specimens to study the high temperature erosion properties. A gas blast type erosion tester was used In examine erosion behavior of the specimens up to 700$^{\circ}C$. In case of GPS silicon nitride, the erosion rate increases up to 500$^{\circ}C$ and decreases over 500$^{\circ}C$. Maximum erosion rate was observed at 300$^{\circ}C$ for HP silicon nitride. The principal factors affecting the high temperature erosive wear of brittle materials are largely dependent on high temperature properties of grain boundaries.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.10a
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• pp.211-212
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• 2009

국내의 다이아몬드 마이크로 블레이드 산업의 경우 충분한 이론적 검증을 거치지 못하고 종전의 경험 및 외산품에 대한 분석을 토대로 제작된 제품에 간단한 물성만을 체크하여 업체에 공급한다 해도 과언이 아니다. 이러한 국내의 실정을 인지하여 본 연구에서는 Cu와 Sn을 주 결합재로 사용한 다이아몬드 마이크로 블레이드에 있어 고체윤활제인 흑연과 $MoS_2$의 첨가에 따른 마모 특성을 비교하였다. 마모시험의 분위기는 상온에서 건식 분위기로 진행 되었으며, 그 결과 흑연을 첨가할 경우 가장 높은 마찰감소를 보임을 확인할 수 있었다. 이번 연구는 상온 및 저 회전 속도에서의 사용을 목적으로 한 다이아몬드공구의 연구 자료로 활용될 것이다.

• Journal of the Korean Society for Heat Treatment
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• v.36 no.6
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• pp.412-421
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• 2023

As the demand for mechatronic systems and high performance increases in the machinery industry, the importance of improving friction characteristics is emphasized. During relative movement of objects, friction and wear occur on two surfaces in contact, and various methods are being designed to increase the lifespan and energy efficiency of machines. The energy increase effect using lubricants is a well-known method. In this study, a micro-sized rectangular grid pattern was produced by applying a precise micro-pattern photo lithography process. Rectangular grid patterns of the same shape and friction behavior according to the size of the pattern were produced in convex and concave shapes, and the tribological characteristics of each were analyzed.

• Journal of the Korean Society of Costume
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• v.39
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• pp.125-138
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• 1998

In order to help apparel manufactures and marketers to promote apparel products more efficiently, and aid them in instilling brand names or brand images more distinctively in the minds of target consumers, it is the intent of this study (1) to investigate on the high-school girls brand loyalty and the brand discernment, self image(product image), and the buying behavior of casual wear. The subjects were 532 female high school students selected from the four high school in Seoul. The data were collected by self-admin-istered questionnaires. The data were analyzed by frequency, percentage, T-test, x2-test, and correspondence analysis. (1) 29.1% of the female students were cat-egorized as the brand loyalty group that was smaller than the non-brand loyalty group(70.9%). (2) In identifying the relationship between the demographic factors and the brand loyalty, the monthly household income and the month-ly personnel expenses were statistically significant. Namely, higher household income and the monthly personnel expenses were statistically significant. Namely, higher household income and the monthly personnel expenses there were, higher the brand loyalty was revealed. (3) The power of discernment was statistically significant according to the brand loyalty. That is, the brand loyalty group was more outstanding than latest fashion brands, the high-price brands, and the better-style brands in terms of design, color, and fabric. (4) The self image was also statistically significant according to the brand loyalty, Wher-eas the brand loyalty group preferred the unique, high-quality, sexy, and active self-images, non-brand loylty group revealed to prefer the non-noticeable and feminine self-images. The findings of this study will assist apparel manufactures and marketers in better identifying the target market, and in subsequently adjusting their products, brand image, and promotional activities in order to reach the target market more efficiently.

• Journal of the Korean Society of Costume
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• v.65 no.1
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• pp.118-135
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• 2015

In recent years, smart clothing had been developed in order to better detect and monitor physical movement of the patient, so that such activities such as location identification and biometric recognition could be done. However, most of the sensing devices of smart clothing were limited to smart sensing sports clothing and the designs did not consider the physical characteristics and the behavior of the wearer. Therefore, this study aimed to create an open protection system by developing a wearable sensing device for health monitoring and location information. For this purpose, this study developed eleven types of wearable sensing design that could be commercially sold and worn by people who needed their biological information to be constantly monitored. The study conducted four tests in order to develop three types of sensing devices for various sensing wears. The purpose of this study was to expand the user rang of smart sensing wears, and provide a foundation for the development of distinctive wearable sensing devices reflecting the user. Furthermore, contribute to the design for the person subject to protection.

• Transactions of the Korean Society of Mechanical Engineers
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• v.11 no.1
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• pp.154-159
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• 1987

In the previously reported Part I, the behavior of the flank wear for carbide tool was studied as a preceeding step to present a simple method for Quick Tool-Life Testing, and the following general equation was obtained $W_{f}$ =(a+bt) $V^{m}$ . In this study the following step-cutting formula for the constants a, b and m in the above general model is derived by using step-cutting data [a numerical formula] To check the validity of the above formula, the comparison is made between the tool-life equation inferred in this method and that inferred in the conventional tool-life testing method, when the wear criterion is 0.3mm. The equation obtained in the present method is V(T')$^{0.57}$=1763 whereas the equation obtained in the conventional tool-life testing method is V(T)$^{0.56}$=1605 The results of the above two formula are satisfactory and also verify the validity of the present research.earch.

• Tribology and Lubricants
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• v.35 no.6
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• pp.337-342
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• 2019

This paper presents an experimental investigation of friction and wear characteristic with respect to patterns occurring on the surface of 3D printed polymer products by fused deposition modeling method. The purpose of this study was to investigate the effect of the patterns and sliding directions on the tribological properties of 3D printed polymer surface. A cubic specimen was printed using polylactic acid filament as the printing material. Friction tests were conducted for different directions with respect to the patterns that were generated on the top and the side surfaces of the specimen, by using a ball-on-reciprocating type tribotester. SUJ2 bearing ball of which the diameter was 11 times greater than the width of the largest pattern was used as the counter surface to assess the frictional behavior. Friction tests were conducted on the top and the side surfaces with respect to the patterns in 3 (0°, 45°, 90°) different directions respectively. Coefficient of friction increased as cycles increased in all cases. The results of the tests showed that the lowest coefficient of friction was measured with the 45° sliding direction on the side surface. The wear rate was the lowest at 45° sliding direction on the side surface, while it was the highest at 0° sliding direction on the top surface. Coefficient of friction of about 0.45 was determined to be the converging value on the top compared to the side surface.

• Fashion & Textile Research Journal
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• v.14 no.3
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• pp.423-429
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• 2012

This study investigated purchasing practice and size satisfaction to offer basic data to establish a marketing strategy and produce down-aging clothes for females in their 40s-50s. For the data analysis, crosstabs, factor analysis, and one-way ANOVA were used. The results were as follows; first, middle-aged women were observed to purchase down-aging clothes "to look younger" and not purchase clothes "due to the lack of right sizes." For women who answered to 'not purchase clothes', they also acknowledged that they intended to purchase down-aging clothes in the future if the right size is available. Second, people in their early 40s significantly considered perceptual qualities such as fashion and brand names while people in their late 50s placed the most importance in practicality and wearability. For body shapes, people with overweight body types were found to significantly consider physical performance, practicality, and wearability. Third, the examination of purchase satisfaction levels by age groups showed that younger age groups had high satisfaction level for wear functionality related items that included size and activity however, the late 50s group had the lowest satisfaction level. Middle-aged women purchased clothes to look younger however, they simultaneously wear clothes that are plain and conservative or respectable and graceful. Therefore, the development of products reflect the analysis of designs that can help create a more youthful appearance and women's preferred styles are needed in addition to the establishment of a differentiated sizing system for middle-aged female consumers in the incorporation of the characteristics of middle-aged women's body parts.