• Journal of the Korean Society for Precision Engineering
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• v.33 no.7
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• pp.559-564
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• 2016

The objectives of this paper are to develop a finite element analysis model to analyze press-fitted and bending load conditions in a press-fitted assembly, and propose a hub shape optimization method to minimize contact pressure near the shaft contact edge. Numerical asymmetric-axisymmetric finite element models have been developed to predict contact stress on press-fitted shafts. The global optimization method, genetic algorithm, local optimization method, and sequential quadratic programming were applied to a press-fitted assembly to optimize the hub contact edge geometry. The results showed that the maximum contact pressure with the optimized hub shape decreased more than 60 % compared to conventional hubs and the maximum contact stress affecting fatigue life was reduced about 47 %. Hub shape optimization can be useful to increase the load capability of press fits in terms of wear and fatigue behavior.

• Journal of Korea Association of Health Promotion
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• v.2 no.1
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• pp.93-104
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• 2004

Purpose : This study was conducted to understand the health status and health behaviors of preschoolers to provide baseline data for developing health promotion programs. Method 'Parents of children attending day-care centers and guardians of preschoolers were recruited for the study. Data were collected from June to August2002 using a structured questionnaire. Result . Among 754 preschoolers, 17,3% were overweight, while 18.2% were underweight, while 15.9% and 23.2% were overweight and underweight respectively, among 85 children living with guardians. The most frequent infectious diseases that children have had previously were hand-foot-mouth disease, chicken pox, and measles. Current health conditions that children have frequently are respiratory disease and atopic dermatitis for bother groups. Only 54%-61% brush their teeth everyday at bedtime, 49%-54% wash their hands every time after returning home, 4.5%-8.8%wear bicycle helmets, 9,3%-11.1% use a child car seat, and 3.5%-8.1% eat fruits and vegetables five times a day, Children living with guardians were less likely toper form positive health behaviors compared with children in day-care centers. Conclusion 'Based on the study results, health professionals could plan and develop health promotion programs to change unhealthy behaviors of preschoolers targeting high-risk groups.

• Journal of computational fluids engineering
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• v.9 no.2
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• pp.11-17
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• 2004

CFD analysis was performed to figure out flow behavior in the inlet plenum of new research reactor where coolant is injected to the flow tubes with the fuel assembly. The computation results showed that large-scale vortices are generated in the inlet plenum by flow stream injected from inlet pipe. These vortices are divided into small vortices and reversed their revolution. They may lead to flow-induced vibration of fuel assembly, moreover, which has been regarded as a cause of fretting wear of fuel assembly. Also there is an another important thing that average velocity of each flow-tube is uneven showing difference in maximum 18%. So it has been suggested that perforated baffle will be installed to prevent the formation of vortex in the inlet plenum. Two perforated baffles, one is flow skirt and the other is muffler type flow straightener, were proposed and their effect was evaluated using commercial CFD code, Fluent. According to CFD analysis for two perforated baffles, it was confirmed that both of them can prevent or reduce vortex formation in the inlet plenum and make average velocity of each flow tube more even.

• Fashion & Textile Research Journal
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• v.9 no.1
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• pp.65-71
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• 2007

This research is to explore relationship between the underwear shopping value and purchasing behaviors, as well as to figure out how the underwear store VM information has influence on consumers' purchase behaviors. Focus is placed on subdividing consumers into different groups according to underwear shopping value, and then verify whether VM information influences the consumer groups differently or not. This study, based on systematic understanding of an underwear consumption, will provide strategic suggestion to establish effective VM information of the underwear brand. The results of this study show that VM information is being utilized by the important clue when the consumers go shopping underwear. That's why the underwear brands should concentrate on developing VM by causing an interest and purchasing of consumers through corresponding with store's individuality and image. Also, the manner of performance should be related to brand image and theme reflected consumer's life style.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.3
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• pp.259-265
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• 2014

When the brakes of a vehicle are applied, large amounts of heat are generated on the surfaces of the brake discs owing to friction between the discs and the brake pads. A high temperature gradient on the disc surfaces leads to thermal deformation and severe disc abrasion. Ultimately, the thermal deformation and disc wear give rise to a thermal judder phenomenon, which has a major effect on the stability of the vehicle. To investigate and propose a solution to these problems, thermoelastic instabilities under applied thermal and mechanical loads were analyzed using the commercial finite element package ANSYS by considering the contact surfaces between the discs and pads. Direct-contact three-dimensional finite elements between the discs and pads were applied to investigate the disc friction temperature, thermal deformation, and contact stress so that the thermal judder phenomenon on the surface of the disc could be predicted.

• Journal of the Korean Society of Clothing and Textiles
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• v.24 no.6
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• pp.787-798
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• 2000

This study intended to investigate the benefits sought in 2(i s female formal wear and the clothing behaviors of 20's working women segmented by the benefits of female apparel and to provide marketing strategy on the segmented market. The subject of this study were 605 working women in their 20's living in seoul, and survey based on references and formal studies was used. The results of data analysis are as follows: 1. The factor structures of the benefit sought in clothing products were classified into symbolismㆍaesthetics, and practicality. 2. Consumer groups were segmented into four groups by the benefit factors sought in clothing products. 3. Product involvement, fashion involvement, information search and brand loyalty were proven significantly different among the segmented consumer groups. Demographic variables and purchasing traits such as subjective social class, average monthly expenditure on clothing, and usage of fashion credit card or credit cards were proven to significantly different among the segmented consumer groups.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.3 s.180
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• pp.47-55
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• 2006

Laser welding of dissimilar metals has been widely used to improve a wear resistance and a corrosion resistance of the industrial parts. The objective of this research is to investigate the influence of the process parameters, such as the welding for SM45C and STS304 with CW Nd:YAG lasers. The bead-on-plate welding tests are carried out for several combinations of the experimental conditions. In order to quantitatively examine the characteristics of the dissimilar welding, the welding quality of the cut section, stress-strain behavior and the hardness of the welded metal are investigated. From the results of the investigation, it has been shown that the optimal voiding condition without defects in the vicinity of the welded area and with a good welding quality is 1600W of the laser power, 0.85m/min of welding speed and $4{\ell}/min$ of pressure for shielding gas.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.27-27
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• 2003

무가압침투법으로 제조된 부피분율 10~24% SiC, TiC, B$_4$C 탄화물 입자강화 7075 Al 합금 기지 복합재료의 건식 미끄럼 마멸거동을 강화입자의 종류, 크기 및 부피 분율을 변수로 연구하였다. 미끄럼 마멸 시험은 pin-on-disk 형태의 마멸 시험기를 사용하여, AISI 52100 베어링강을 상대재로 상온 대기 중에서 실시되었다. 마멸특성의 분석과 마멸기구의 규명을 위하여 마멸면과 마멸단면을 SEM, EDS를 이용하여 분석하였다. 제조된 복합재료의 압축 시험을 통하여 측정된 항복강도와 가공경화지수는 서로 반비례하였고, 각 시편간의 경도 차는 크지 않았다. 마멸 시험결과, 크기 및 부피 분율이 7$\mu\textrm{m}$ !0%인 SiC 입자로 강화된 복합재료를 제외하고, 전체 복합재료 시편은 7075 Al 기지 합금에 비해 낮은 마멸 속도를 보였다. 10N 이하의 저하 중에서는 강화상의 종류와 상관없이 복합재료는 낮은 마멸 속도를 보였고, 25N 이상의 고하중에서는 TiC 입자강화 복합재료가 가장 낮은 마멸 속도를, SiC 입자강화 복합재료가 가장 높은 마멸 속도를 나타내었다. 강화 입자의 크기 및 부피 분율이 동일한 경우 SiC 입자로 강화된 복합재료가 가장 낮은 내마멸성을 나타내었다. 강화상의 크기 및 부피 분율이 증가함에 따라 미소 마멸에서 격렬 마멸로의 천이 하중이 증가하였다.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.1
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• pp.68-74
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• 2016

The Nd:YAG laser welding process is one of the most advanced manufacturing technologies owing to its high speed and penetration, and has increased the automation and flexibility of an entire industry. Laser welding of dissimilar metals has been widely used to improve the wear resistance and corrosion resistance of industrial parts. The objective of this research is to investigate the influence of process parameters on the welding of SM45C and STS304 with CW Nd:YAG lasers. Bead-on-plate welding tests were carried out for several combinations of the experimental conditions. In order to quantitatively examine the characteristics of the dissimilar welding, the welding quality of the cut section, strain-stress behavior, and hardness of the welded part were investigated.

• Journal of the Korean Society of Clothing and Textiles
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• v.38 no.4
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• pp.495-505
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• 2014

This study investigated the type of fashion brand concepts and derived the components of fashion brand concepts. A total of 125 brand concept texts of women's wear brands were collected from "2012/2013 Korea Fashion Brand Annual" (S. M. Kim, 2012). A qualitative research method was employed. To investigate the types of fashion brand concepts, the texts were classified into three types such as functional, symbolic, and experiential concepts, and four complex types such as functional/symbolic, functional/experiential, symbolic/experiential, and functional/symbolic/experiential concepts. Open coding and axial coding provided the components of fashion brand concepts. The results were as follows. First, an investigation of the types of fashion brand concepts indicated differences in the types of fashion brand concepts and the types of general product brand concepts. One content of a fashion brand concept could be interpreted as more than two concept types; consequently, many fashion brand concepts did not fit the notion of the types of general product brand concept. Most fashion brand concepts simultaneously encompassed more than two types of brand concepts at once. Second, the components of fashion brand concepts consisted of 55 subjects, 7 sub-categories (physical/intrinsic product characteristics, symbolic/conceptual product characteristics, target demographics, target consumer behavior, brand capability, brand values, and brand management/marketing) and 3 categories (product, target consumer, and brand).