• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.4
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• pp.184-192
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• 2001

Cam/tappet wear is one of the critical concerns in valve train deign. Maximum contact stress and minimum oil film thickness between the cam and tappet are usually checked for the estimation of wear characteristics. If the two extreme cases arise simultaneously, there is a strong possibility of cam/tappet wear. In this paper, effects of valve train layout on the wear characteristics were studied. Especially for swinging arm type valve trains, initial geometric layout must be very carefully defined to avoid wear problems. The study was performed fur an end pivot type OHC valve train, which had severe wear problems. Analysis results show that some geometric parameter affect very sensitively on the wear characteristics. Experiments were also performed for the original and modified valve trains, which strongly support the analysis results.

• Tribology and Lubricants
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• v.15 no.3
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• pp.265-271
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• 1999

Wherever there are rotating equipment and contact between surface, there is wear and the generation of wear particles. The particles contained in the lubricating oil carry detailed and important information about the condition monitoring of the machine. This information may be deduced from particle shape, composition, size distribution, and concentration. Therefore, This paper was undertaken to Ferrography system of wear debris generated from lubricated moving machine surface. The lubricating wear test was performed under different experimental conditions using the Falex wear test of Pin and V-Block type by Ti(C, N) coated. It was shown from the test results that wear particle concentration (WPC) and wear severity Index( $I_{S}$), size distribution in normal and abnormal wear have come out all the higher value by increases sliding friction time. Wear shape is observed on the Ferrogram it was discovered a thin leaf wear debris as well as ball and plate type wear particles. This kind of large wear shape have an important effect not only metals damage, but also seizure phenomenon.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.1 s.94
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• pp.182-190
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• 1999

The objective of this study is to develop an analysis scheme in order to predict regrinding due to tool wear in shearing process. The analysis of material now and fracture in shearing process should precede the prediction of tool wear. Thus the developed FE-program to analyze shearing process is used. In order to predict tool wear, the wear model is reformulated as an incremental form and then the wear depth of tool is calculated at each deformation path. Because the regrinding of shearing tool is determined on the basis of allowable size of burr, the analysis of shearing process is iteratively performed using the worn profile of tool. To show the effectiveness of the scheme the simulation result is compared with experimental one.

• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.7 s.144
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• pp.926-937
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• 2005

The analysis category of Art to Wear was text analyzed from the research material of 100 projects put together by fashion specialist. The conclusion of Art to Wear was comprehended the general features of it were compared and analyzed from a semiotics context. According to this analysis, the formative features of modern Art to Wear is categorized into three different dimensions from a semiotics light. The formative features of modem Art to Wear in the light of syntactic dimension was divided as an open constructed shape of Space Extension, non-typical Deformation, Geometrical Plasticity. The formative features of modem Art to Wear in the light of semantic dimension express symbolic meaning through metaphorical sign. These sign reflect the body image of the life and death and its objective of Abjection, Hybrid of discultural appearance and the image of Hyper-reality, which are features used to comprehend the inner meaning. The formative features of modem Art to Wear in the light of pragmatic dimension divided the artist emotion and meaning system delivered by Emotive Image, the Phatic Image that arouse inner signification and the Poetic Image which contain artistic and aesthetic meaning within it.

• Fashion & Textile Research Journal
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• v.11 no.1
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• pp.48-56
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• 2009

The purposes of this study were to segment knit wear consumers by their lifestyles and to examine knit wear purchase behavior among the lifestyle segments. The subjects of this study were female consumers who were residents in Seoul and metropolitan areas. The researchers distributed the questionnaires and the final sample of 357 was used for the data analysis. The statistical analysis methods used for the study were factor analysis, cluster analysis, ANOVA, Duncan test, and ${\chi}^2$-test. The results showed that the lifestyle factors had 6 dimensions: fashion, planned purchase, socially active, impulsive consumption, brand, and leisure/culture. These factors were categorized into four groups: brand oriented group, passive group, rational/social group, and fashion/impulsive consumption group. The results also showed that there were significant differences among the groups in regard to knit wear purchase criteria, knit wear image preferences, and other knit wear purchase behaviors. For example, brand oriented group considered design and brand name/fashion important as knit wear selection criteria, and the group preferred an elegance image and a modern image than did other groups.

• Tribology and Lubricants
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• v.34 no.4
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• pp.146-159
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• 2018

This paper presents a wear analysis procedure for calculating the wear of journal bearings of a four-strokes and four-cylinder engine operating at a constant angular crank shaft speed during firing conditions. To decide whether the lubrication state of a journal bearing is in the possible region of wear scar, we utilize the concept of the centerline average surface roughness to define the most oil film thickness scarring wear (MOFTSW) on two rough surfaces. The wear volume is calculated from the wear depth and wear angle, determined by the magnitude of each film thickness on a set of oil films with thicknesses lower than the MOFTSW at every crank angle. To calculate the wear volume at one contact, the wear range ratio during one cycle is used. The total wear volume is then determined by accumulating the wear volume at every contact. The fractional film defect coefficient, asperity load sharing factor, and modified specific wear rate for the application of the mixed-elasto-hydrodynamic lubrication regime are used. The results of this study show that wear occurs only at the connecting-rod big-end bearing. Thus, simulation results of only the big-end bearing are illustrated and analyzed. It is shown that the wear volume of each wear scar group occurs consecutively as the crank angle changes, resulting in the total accumulated wear volume.

• The Research Journal of the Costume Culture
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• v.17 no.2
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• pp.352-366
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• 2009

The purpose of this study was to investigate the actual wearing conditions and the preferences of knit wear school uniforms. The subjects were 480 high school girls from 6 high schools placed in Daejeon. The method of study is a survey consisted of actual wearing conditions questionnaires, preferences questionnaires, and demographic attribution. Data was analyzed by frequency, variance, crosstabs, and correlation analysis using SPSS 12.0 program. The results of study are as follows. First, high school girls over 90% wearing knit wear school uniforms were satisfied with current knit wear school uniforms(navy color, V-neck, and wool mixed). Second, high school girls preferred 100% cotton material and black/white/gray color group. The style of knit wear school uniforms was most preferred monochrome cardigan with cable pattern. High school girls wanted to show neat image by knit wear school uniforms and to diversify the style of them. Third, the differences of preferences between groups, they were wearing knit wear school uniforms(A group) or not(B group), were about pattern and improvement. A group preferred school mark pattern, and wanted to improve the quality and after service. B group preferred monochrome cable pattern, and wanted to diversify the style. Both groups wanted to wear knit wear school uniforms because knit wear was 'warm' and 'comfort'. Consequently, knit wear school uniforms will help high school girls express individuality and beauty.

• Tribology and Lubricants
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• v.39 no.3
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• pp.118-122
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• 2023

In our study, we develop a finite element model based on Archard's wear law to predict the cumulative wear and the evolution of the tool profile in friction stir welding (FSW) applications. Our model considers the rotational and translational behaviors of the tool, providing a comprehensive description of the wear process. We validate the accuracy of our model by comparing it against experimental results, examining both the predicted cumulative wear and the resulting changes to the tool profile caused by wear. We perform a detailed comparison between the predictions of the model and experimental data by manipulating non-dimensional coefficients comprising model parameters, such as element sizes and time increments. This comparison facilitates the identification of a specific non-dimensional coefficient condition that best replicates the experimentally observed cumulative wear. We also directly compare the worn tool profiles predicted by the model using this specific non-dimensional coefficient condition with the profiles obtained from wear experiments. Through this process, we identify the model settings that yield a tool wear profile closely aligning with the experimental results. Our research demonstrates that carefully selecting non-dimensional coefficients can significantly enhance the predictive accuracy of finite element models for tool wear in FSW processes. The results from our study hold potential implications for enhancing tool longevity and welding quality in industrial applications.

• Journal of the Korea Fashion and Costume Design Association
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• v.13 no.1
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• pp.21-35
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• 2011

Thanks to the popularization of golf, the population of young golfers including female players has been continuously increasing and the market specialization of golf-wear has been gradually intensifying with a growing number of new import brands in the market. This study is aimed to provide a direction to strengthen and invigorate the competitiveness of domestic golf wear brands through research on the benefits pursued by, the purchase attitudes towards local and overseas brands and the purchasing behaviors of female customers who have emerged as the newest customer group in the golf-wear market. The subjects of the research were 409 female golfers and the statistical analyses used for the study were factor analysis, cluster analysis, ANOVA, Scheffe test, and chi-square test. The results showed that there were six factors sought for golf-wear benefits: figure compensation, brand orientation, comfort, youth/fashion, maturity/conformity, and individuality. Cluster analysis showed that there were three groups of golf-wear benefits sought. Overall, the three groups were different in regard to golf involvement and golf-wear preferences. Based upon the results mentioned above, this study summarizes the key features of each group and can provide applicable suggestions for conducting strategic marketing activities.

• Tribology and Lubricants
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• v.33 no.4
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• pp.168-186
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• 2017

This paper presents a wear analysis procedure for calculating the wear of journal bearings during the start-up and coast-down cycles of a motoring stripped-down single cylinder engine operating with a tilted shaft. In order to decide whether the lubrication state of a journal bearing is in the mixed-elasto-hydrodynamic lubrication regime, we utilize lift-off speed and MOFT (most oil film thickness) under mixed-elasto-hydrodynamic lubrication regime at the corresponding aligned shaft. We formulate an equation for the modified film thickness in a misaligned journal bearing considering the additional wear volume described in Part I of this study. For this, we use the calculation results of the degree of misalignment and tilting angle obtained after finding the eccentricities of the two bearings supporting the crankshaft of a single cylinder engine. In this Part II, we calculate the wear of journal bearings using the fractional film defect coefficient, the asperity load sharing factor, and the modified specific wear rate for the application of mixed-elasto-hydrodynamic lubrication regime. We show that the accumulated wear volume after turning the ignition switch on and off once, increases to ${\sigma}=39{\mu}m$ and then decreases from ${\sigma}=39{\mu}m$ with increasing in surface roughness.