• Elastomers and Composites
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• v.58 no.2
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• pp.81-86
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• 2023

Asphalt pavements are generally composed of fine and coarse aggregates, bitumen, and modifier. Asphalt pavement wear particles (APWPs) are produced by friction between the road surface and the tire tread, and they flow into the environment such as rivers and oceans. Model APWPs were prepared and a single APWP of 212-500 (S-APWP) and 500-1000 ㎛ (L-APWP) was analyzed using thermogravimetric analysis (TGA) to investigate inhomogeneity in the compositions of the APWPs. The reference TGA thermogram was built using thermograms of the raw materials and formulation of the model asphalt pavement. The compositions of the APWPs were different from each other. Ash contents of the APWPs were lower than expected. Inhomogeneity in the total contents of bitumen and modifier was more severe than that in the other components. The inhomogeneity of the S-APWPs was more severe than that of the L-APWPs.

• Journal of the Korean Society for Precision Engineering
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• v.10 no.4
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• pp.94-103
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• 1993

In this work, the imaginary part of the inner modulation transfer function of the cutting dynamics is introduced for tool wear monitoring. Time-series method is utilized to construct the general three dimensional cutting dynamics whose imaginary part of the inner modulation transfer funcition shows the proportionality to tool wear at the natural frequency of the machine tool dynamics. Thus model is reduced to single-input single-output model without altering the proportionality characteristics to tool wear and implemented to the dual computer system in which one computer performs measurement while the other calculates the imaginary part of the inner modulation transfer function of the cutting dynamics by the batch least square method. The values of the imaginary part at the natural requency of the machine tool structure in the cutting direction are compared to the one calculated during machining with a brand new tool to decide the current status of the tool. The experiments shows the relevance of the proposed concept.

• Journal of the Korean Society of Clothing and Textiles
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• v.37 no.4
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• pp.565-576
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• 2013

This study investigated 1) the effects of mountain climbing motivation on the desired mountain climbing wear benefits, and 2) the desired effects of mountain climbing wear benefits on clothing usage behavior. Data were collected via a questionnaire administered to 498 consumers who make at least one mountain climbing wear purchase for personal use. All items were evaluated on a 5-point Likert scale, and SPSS 20.0 and Amos 7.0 were used for data analysis. Confirmatory factor analysis for the research variables were performed and three factors of mountain climbing motivation (social interaction, health improvement, and mental rejuvenation), four factors of mountain climbing wear benefits sought (ostentation, ideal healthy figure, conformity, and functions), and two factors regarding clothing usage behavior (sportswear usage and daily wear usage) were identified. The results from the model test were as follows: 1) Mountain climbing motivation was found to vary depending on the mountain climbing wear benefits sought. Social interaction had a positive effect on all 4 factors of mountain climbing wear benefits sought. Health improvement was the only motivating factor for consumers who sought the benefit of functions; however, the functions benefit was not found to be a consideration for consumers who climbed for mental rejuvenation. 2) Mountain climbing wear usage was affected by mountain climbing wear benefits sought. The benefits for conformity and functions had a positive effect on sportswear usage and daily wear usage; however, the ideal healthy figure only affected daily wear usage. The twofold usage of mountain climbing wear reflects a cultural trend toward the usage of mountain climbing wear as daily wear; however, consumers show this twofold usage to conform successfully to mainstream society and not to pursue the ideal healthy figure.

• Journal of the Korean Society of Clothing and Textiles
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• v.40 no.4
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• pp.733-745
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• 2016

This study investigated the effect of clothing interest on party preference and suggested four party unities according to party wear types. A hypothesized model based on consumer innovativeness, clothing interest, party benefit, party interest and party preference was tested to determine the effect of clothing interest on party preference. Party unities were constructed according to party wear types along with party place, party food, and party music. Data was collected through two online surveys. The population of the survey was female consumers in their twenties. Descriptive statistics, factor analysis, reliability, correlations, and regressions were applied to the data of 305 samples. As a result, positive tendency toward consumer innovativeness, clothing interest, party benefit, party interest and party preference was observed in young female consumers with significant relations among five variables. Party preference was well-explained from the hypothesized research model, but the direct path from clothing interest to party interest was identified as insignificant. The most preferred party elements of place, food, music and wear was garden, barbecue, house music and mini dress, respectively. Four party unities according to party wear types were constructed and suggested based on the correlation analysis results between party wear and other party elements. The concept of party unity is useful to establish marketing strategies such as advertising and experience marketing in the party wear industry.

• Journal of the Korea Fashion and Costume Design Association
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• v.9 no.1
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• pp.203-219
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• 2007

The education chance and job opportunity of women have increased in the 19th century. Also, women tried to get the right and chance equal to men in this period. Therefore, the population of women participating in the sports have increased. And comfortable and practical pantaloons which men have been wearing were suggested to women. This study investigated the characteristics and change of women's sports wear relating to social change in the 19th century. The results of this study were as follows: 1. According to the social change, women participated in the sports activities with the opportunity equal to men, and the appropriate women's sports wear was needed. 2. Pantaloons which were suggested as the clothing reform movement became popular with the development of sports wear. 3. Simple, effective, comfortable and easy style sports wear was preferred. 4. Women accepted men's sports wear positively. 5. The women's sports wear varied according to the various kinds of sports. 6. The healthful design was preferred and harmful design was excluded. 7. Underwear was improved functionally and simplified. 8. The main materials were flannel, wool, tweed, homespun and serge, and the mail colors were brown, dark blue, gray and black.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.575-578
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• 2000

Die design to minimize the die wear in the cold forging process is very important as it reduce the production cost and the increase of the production rate. The quantitative estimation for the die wear is too hard because the prediction of the die wear is determined with many process variables. So, in this paper, the optimal shape of the backward extrusion punch is newly designed through the FE-analysis considering the surface expansion and Archard's wear model in order to reduce the rapid wear rate that is generated for the backward extrusion product exceeding the forming limit. The main shape variables of the backward extrusion punch are the flat, angle, and round of the punch nose part. As the flat and angle of the punch nose are larger, the surface expansion is reduced. and, the wear rate is decreased according to the reduction of the punch round. These results obtained through this study are applied to the real manufacturing process, it is implemented the reduction of the wear rate.

• Journal of the Korean Society for Precision Engineering
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• v.10 no.1
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• pp.34-41
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• 1993

SUS304 is wellknown as difficult-to-machine materials. It is easy to appear workhardened, and workhardening is one of the causes of groove wear on the tool. In this paper, the author would like to compare the width of flank wear with that of groove wear, and to find whether the groove wear can be used as a criterion of a tool life. The design of the twelve tests provides three levels for each variable (speed: 200m/min, 118m/min, 70m/min; feed: 0.3mm/rev, 0.17mm/rev, 0.1mm/rev; depth of cut: 0.4mm, 0.28mm, 0.2mm). The study of tool-life testing by statistical technique follows usual most scientific sequence. So the tool-life predicting equation is calculated by the method of least squares. The overall adequacy of the model can be verified by the analysis of variance. The results obtained are as follows : 1) When SUS304 is cut in 200(m/min), the width of flank wear is much larger than that of groove wear. 2) In cutting speed 118m/min, flank wear is a little larger than groove wear and in the cutting speed 70m/min, the latter is a little larger so that it is reasonable to determine the tool life according the crierion by groove wear in the low cutting speed (less than 70m/min). 3) Owing to the burr the depth of engagement along the cutting edge is extended toward the shank.

• Journal of Ocean Engineering and Technology
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• v.2 no.2
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• pp.87-95
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• 1988

This paper is studied to know corrowive wear characteristics of austempered ductile cast ironin corrosive environments against mating SM45C hardened two test pieces in distilled water and NaCl aqueous solution. The corrosive wear mechanism was investigated by scanning electron microscopy and retained austenite volume fraction was investigated by X-ray diffractometer. The experimental result show that the corrosive wear characteristics depend largely on the $\textrm{Fe(OH)}_{3}$which is influenced by the critical sliding distance $L_{cr}$ and $L_{cr}$ shorted with increasing NaCl concentration. It was found that the carbides in matrix have a significant effect on their corrosive wear resisance and the fine acicular bainite showed corrosive wear resistance stronger than that of the coarse acicular and platelet bainite. From above results the model of corrosive wear mechanism in corrosive environments is proposed.

• Transactions of Materials Processing
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• v.33 no.2
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• pp.112-117
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• 2024

In this study, the friction and wear characteristics of Inconel 600 in the superplastic forming process of Ti6Al4V were evaluated through pin-on-disc tests. To achieve an efficient and systematic experimental design, the Taguchi method was employed. The wear track of the Inconel 600 pin showed scratches in the sliding contact direction, confirming that the wear mechanism is abrasive wear. Through sensitivity analysis such as ANOVA and Main effects, it was confirmed that both normal force and sliding distance have a significant impact on the wear. Changes in sliding velocity and distance did not affect the friction coefficient, which remained relatively constant at approximately 0.380. The wear prediction model for Inconel 600 in the superplastic forming of Ti6Al4V was constructed, which can be utilized as a guideline for the prediction and management of tool wear.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.4
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• pp.67-73
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• 2014

The dry sliding wear behavior of graphite that is used as the sealing material to cut off hot gas was evaluated as a function of applied load, sliding speed and temperature. The reciprocating wear tests were carried out at room temperature and elevated temperatures. An attempt has been made to develop a mathematical model by response surface methodology and an analysis of variance technique was applied to confirm the validity of the developed model. Also, the wear mechanism was compared through the observation of the worn surface by SEM analysis.