• Elastomers and Composites
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• v.56 no.3
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• pp.172-178
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• 2021

The wear behavior of styrene-butadiene rubber (SBR) and butadiene rubber (BR) was investigated using a blade-type abrader with a steel blade (SB), Ti-coated tungsten carbide blade (TiB), or zirconia blade (ZB). The wear rate of SBR against SB and TiB decreased with increasing number of revolutions because of the blunting of the blades during wear. However, the wear rate of SBR against ZB remained nearly constant with little blade blunting. Generally, the wear rate of BR was largely unaffected by the blade material used for abrasion. The wear rate and frictional coefficient of SBR were found to be higher than those of BR at similar levels of frictional energy input. A power-law relationship was found between the wear rate and frictional energy input during abrasion. A well-known Schallamach pattern was observed for SBR, while a much finer pattern was observed for BR. The blade material affects the wear rate of the rubbers because the macromolecular free radicals and blade tend to undergo mechano-chemical reactions. The inorganic ZB was found to be the most inert for such a mechanism.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.5
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• pp.98-107
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• 1995

The in-process detection of drill wear and breakage is one of the most importnat technical problems in unmaned machining system. In this paper, the monitoring system is developed to monitor abnormal drilling states such as drill breakage, drill wear and unstable cutting using motor current. Drill breakage is detected by level monitoring. Tool wear is classified by fuzzy pattern recognition. The key feature for classification of tool wear is the estimated flank wear which is calculated by the proposed flank wear model. The characteristic of the model is not sensitive to the variation of cutting conditions but is sensitive to drill wear state. Unstable cutting states due to the unsmooth chip disposal and the overload are monitored by the variance/mean ratio of spindle motor current. Variance/mean ratio also includes the information about the prediction of drill wear and drill breakage. The evaluation experiments have shown that the developed system works very well.

• Journal of the Korean Society of Costume
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• v.52 no.8
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• pp.29-39
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• 2002

It was increased leisure hours by automation and computerization of industry. Many people spend on hours in enjoying leisure sports, and then. nowadays, Many women tend to prefer casual wear to formal suits. The purpose of this research was to design of outdoor-wear that improve the functional and aesthetic effects for clothing comfort. Total 4 design prototype consisting of jumper and slacks were developed for this research. Outdoor-wear design forced on armhole type of jumper and ease of the back crotch length of slacks to improve the functional and aesthetic effects. And Outdoor-wear design focused on color harmony to aesthetic effects. Ease amount and materials of jumper and slacks were controlled. Design A: Jumper was designed as dropped shoulder with set-in steeve and band collar, A break-away zipper to facilitate ventilation control were made the area of back of jumper and the area of outside seam line of slacks Color of jumper and slacks were olive green color. Ease amount of the crotch length of slacks pattern was constructed as 7% of total crotch length: Design B 4DM cut pattern were applied to the jumper and slacks pattern. A break-away zipper to facilitate ventilation control were made the area of back of jumper and the area of inside seam line of thigh. Color of jumper and slacks were grey and orange color. Ease amount of the crotch length of slacks pattern was constructed as 5% of total crotch length. Design C : Jumper was designed as the set in sleeve and hood. and A break- away zipper to facilitate ventilation control were made the ares of the armhole and elbow. Color of jumper and slacks were ivory and orange color. Ease amount of the crotch length of slacks pattern was constructed as 5% of total crotch length. Design D : Jumper was designed as raglan sleeve. Color of jumper and slacks were olive green color. Ease amount of the crotch length of slacks pattern was constructed as 5% of total crotch length. Total six females, ages 20-45, served as subjects for this research. Subjects have standard body type, generally, wearing 66 size of ready-to-wear clothing. The performance of the newly designed outdoor-wear was evaluated for their effectiveness in several aspects such as conditions of skin temperature, sensory evaluation of comfort during body movements, appearance and color harmony and aesthetic collar design. Design 3 was appeared to be the most positive in aesthetic evaluation and functional effects of design 2 of 4DM cut pattern was appeared to be beter than other designs.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1998.10a
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• pp.164-169
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• 1998

This paper deals with condition monitoring for tool wear during tuning operation. To develop economic sensing and identification methods for turning processes, sound pressure measurement and digital signal processing technique are proposed. To identify noise sources of tool wear and reject background noise, noise rejection methodology is proposed. features to represent condition of tool wear are obtained through analysis using adaptive filter and FFT in time and frequency domain. By using fuzzy pattern recognition, we extract features, which are sensitive to condition of tool wear, from several features and make a decision on tool wear. The validity of the proposed system is condirmed through the large number of cutting tests in two cutting conditions.

• Transactions of Materials Processing
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• v.13 no.1
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• pp.59-64
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• 2004

Nano-scratch tests were performed on PMMA thin films spin-coated on a Si substrate using an atomic force microscopy (AFM) with loads ranging form 10nN to 100nN. At low loads, a ridge pattern was formed on the PMMA thin film surface. No wear particles were observed during the pattern-forming mild wear. At high loads, severe wear by plowing occurred, accompanied by wear particles. The film with the highest hardness showed the highest wear resistance. Friction force generated during the scratching was measured, which was closely related with surface deformation of the film. A simple empirical equation to deduce scratch hardness of the film from a linear fixed-distance scratch test was proposed, and scratching-speed dependency of the scratch hardness was displayed.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.7 no.1
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• pp.69-74
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• 1998

In order to monitor the tool wear in milling operation, cutting force is measured as the tool wear increased. The digital signal processing methods are used to detect the tool wear . As AR parameter extract the feature of tool wear , it can be used as input parameter of pattern classifier. The FFT monitor the tool wear exactly , but it can not do real time signal processing. The band energy method can be used to real time monitoring of tool wear ,but int can degrade the exact monitoring.

• The Korean Journal of Community Living Science
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• v.28 no.4
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• pp.505-514
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• 2017

Although studies on the development of cool touch fabrics have been conducted widely, the effects of fitted pattern on enhancing the cooling sensation are insufficient. To investigate the effect of cool-touch fabric and fit of women's sports underwear, 3D and 2D patterns of sleeveless top and sports leggings were constructed. The performance of cool touch was tested by the Qmax value and wear test with nine subjects. Objective fit evaluation was observed by 3D virtual clothing using Clo software. Subjects rated wearing sensation such as 'cooling sensation, fit, wear comfort and preferences of purchase' using Likert's scale in the environmental chamber at $25^{\circ}C$, 45 %RH. The Qmax value of the cool touch fabric was higher than that of the PET fabric, which was well reflected in 'cooling sensation', especially in the case of a tight-fitted 3D pattern. The cooling sensation of the cool-touch fabric was not significantly elevated with 3D tight pattern as long as the size of the 2D pattern was similar to that of 3D pattern. However, the purchase preference was highly correlated with 3D fit and wear comfort.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.645-646
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• 2010

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.1007-1008
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• 2008

• Journal of the Korean Society for Heat Treatment
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• v.34 no.3
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• pp.130-136
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• 2021

With the development of the industry, bearings that require higher durability and efficiency are required, and various methods to reduce friction and wear of bearings are being studied. In this study, a wear test was conducted for STB2, a bearing steel material, by machining a micro-line pattern on the race surface of the bearing by machining. The pattern pitch of the specimens was processed to 40㎛, 80㎛, and 150㎛, and the coefficient of friction characteristics were investigated for the unpatterned specimen and the specimen with a DLC thin film deposited on the surface. As a result of the wear test, the pattern pitch showed the smallest coefficient of friction at 40㎛, and it was confirmed that the smaller the pattern pitch, the better the tribology characteristics.