• Tribology and Lubricants
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• v.13 no.2
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• pp.16-26
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• 1997

In this paper, the characteristics of lubrication and wear phenomena of journal bearing with respect to film parameter and Sommerfeld number variation are investigated experimentally and the design criterion for the hydrodynamic journal bearing is presented to avoid wear and seizure. Experimental work is performed with various rotating speed and load, and lubricant is used synthetic oil and mineral oil. By the results of the experiment, it is found that friction coefficient is decreased as Sommerfeld number is decreased, and that wear phenomenon is observed when Sommerfeld number is below $9$\times$10^{-4}$ and there are much alike in wear properties between synthetic and mineral oil.

• Journal of the Korean Society for Railway
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• v.10 no.6
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• pp.772-778
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• 2007

For the wear characteristics assessment of Saemaul train passing through curves, an analysis model for multi-car system has been developed. By using this model and ADAMS/Rail, sensitivity analyses have been conducted for the wear characteristics by changing the related parameters. At low speed, the wear number and the sliding mean of right wheel showed higher than left wheel, while those of left wheel showed higher than right wheel at high speed. According to the decrease of curve radius, the wear number and the sliding mean were increased. When the length of transition curve was increased, the wear number and the sliding mean was increased. And according to increase of cant, the wear number and the sliding mean were increased.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.103-104
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• 2006

Wear of valve seating face and seat insert seating face influence the performance of engine, so they are important. To manufacture good quality valve and seat insert which have wear resistance the relations between wear factors and wear of the two seating faces have to be inspected. Cycle number is one of the important wear factors wearing the two seating faces and it can translate into mileage in rear car. But little is blown. Test variable is only cycle number and the cycle numbers are $2.0{\times}10^6,\;4.0{\times}10^6\;6.0{\times}10^6,\;8.0{\times}10^6$. And the other test conditions were fixed. Rmax of valve seating face and seat insert seating face increase linearly as cycle number is increased. Rmax of valve seating face were smaller than seat insert seating face in each cycle number. Reaction production by tribological reaction and sliding wear was found on the two faces.

• Journal of Power System Engineering
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• v.12 no.3
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• pp.44-49
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• 2008

In this research, I would like to choose sliding distance and ventilated hole number which affect to the amount of wear of disk and pad as experiment conditions of 'the amount of wear' through wear test of motorcycle brake disk. Also, I analyze the amount of wear according to the variation of coefficient of friction by using design of experiment that is being widely used in diverse areas. With the tests of least, I present the correlation of each experiment condition. Therefore, I analyzed the variation of the amount of wear of disk and pad according to test factors such as ventilated hole number, applied load, sliding speed, and sliding distance in wear test of motorcycle brake disk by applying the design of experiment. Also, I analyzed quantitatively the influence of test factors through Taguchi Robust experimental design, response surface and examined the most suitable level and estimation of the amount of wear of disk. From these, I reached the following conclusions. response surface design, mathematical model was constructed about amount of wear of disk and pad. The amount of wear that decrease according to increase of ventilated hole number, and it's increase according to Increase of applied load, sliding speed, and sliding distance.

• Journal of Mechanical Science and Technology
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• v.15 no.9
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• pp.1274-1280
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• 2001

The fretting wear behavior of the contact between Zircaloy-4 tube and Inconel 600, which are used as the fuel rod cladding and grid, respectively, in PWR nuclear power plants was investigated in air. In the study, number of cycles, slip amplitude and normal load were selected as the main factors of fretting wear. The results indicated that wear increased with load, slip amplitude and number of cycles but was affected mainly by the slip amplitude. SEM micrographs revealed the characteristics of fretting wear features on the surface of the specimens such as stick, partial slip and gross slip which depended on the slip amplitude. It was found that fretting wear was caused by the crack generation along the stick-slip boundaries due to the accumulation of plastic flow at small slip amplitudes and by abrasive wear in the entire contact area at high slip amplitudes.

• Tribology and Lubricants
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• v.36 no.5
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• pp.262-266
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• 2020

Herein, we present a numerical investigation of wear analysis of sliding systems with a constant speed subjected to Archard's wear law. For this investigation, we compared two methods: eigen-wear analysis and adaptive meshing technique. The eigen-wear analysis is advantageous to predict the evolution of contact pressure due to wear using the initial contact pressure and contact stiffness. The adaptive meshing technique in finite element analysis is employed to obtain transient wear behavior, which needs significant computational resources. From the eigen-wear analysis, we can determine the appropriate element size required for finite element analysis and the time increment required for wear evolution by a dimensionless variable above a certain value. Since the prediction of wear depends on the maximum contact pressure, the finite element model should have a reasonable representation of the maximum contact pressure. The maximum contact pressure and wear amount according to this dimensionless variable shows that the number of fine meshes in the contact area contributes more to the accuracy of the wear analysis, and the time increment is less sensitive when the number of contact nodes is significantly larger. The results derived from a two-dimensional wear model can be applied to a three-dimensional wear model.

• The Research Journal of the Costume Culture
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• v.21 no.5
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• pp.765-779
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• 2013

This paper studied why middle-aged group is using active wear as casual wear. First, we can think of 'comfort', 'ideal body shape', 'trend', 'functionality', 'economy' for the reasons. We categorized the incentives as 'comfort/functionality pursuits', 'trend/economy pursuits', and 'ideal body shape pursuits'. Studies showed that statistically significant number of men pursue comfort and functionality, and statically significant number of women pursue trend and economy. Second, this study shows that the number of consumers who use the active wear in daily lives is greater than that of those who use it only for outdoor activities. The difference was statistically significant in T-shirts and pants. The most frequent usage was in social activities, and the next frequent usage was in cultural activities. The reason is that currently, middle-aged consumers are actively participating in social gatherings than any other activities. Especially, considering that the men wear active wear more than the women do, development of the product as men's casual wear that is compatible with other apparels will be necessary. We expect this study will be used as the preliminary data for a marketing strategy targeting the middle-ages.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.813-819
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• 2008

For the wear characteristics assessment of Saemaul train passing through curves, an analysis model for multi-car system has been developed. By using this model and ADAMS/Rail, sensitivity analyses have been conducted for the wear characteristics by changing the related parameters. According to the increase of running speed, the wear number, the sliding mean and friction coefficient were increased. At high speed, the wear number, the sliding mean and friction coefficient of left wheel showed higher than right wheel. If the cant increased, the wear number the sliding mean and friction coefficient increased. but decreased based on the balance cant value by the curvature and running speed.

• Tribology and Lubricants
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• v.23 no.6
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• pp.301-305
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• 2007

The wear particle analysis has been known as very effective method to foreknow and decide a moving situation and a damage of machine parts by using the digital computer image processing. But it was not laid down and trusted to calculate shape parameters of wear particle and wear volume. In order to apply image processing method in the foreknowledge and decision of lubricated condition, it needs to verify the reliability of the calculated data by the image processing and to lay down the number of images and the amount of wear particle in one image. In this study, the lubricated friction experiment was carried out in order to establish the optimum image capture with the SM45C specimen under experiment condition. The wear particle data were calculated differently according to the number of image and the amount of wear particle in one image.

• Fashion & Textile Research Journal
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• v.13 no.1
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• pp.1-6
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• 2011

Design patent is a type of industrial design right that is granted on the ornamental design of a functional item. We analyzed domestic design patents that were applied from 1965 until 2008, to the field of functional clothing. Since the year 2000 the number of design patents of functional clothing progressively increased. Design patents applied to the functional clothing field includes sport wear (47%), working clothes (34%), and leisure wear (19%). Design development of the sports wear from the latter half of 1990's has shown a continuously increasing tendency. The most patent applications belonged to the companies(51.4%), followed by individual applicants (46.6%), and the universities or laboratories had the least number of applications (2.0%). In case of working clothes or the leisure wear, the number of design applications focusing on the functional characteristic is higher than that of aesthetic characteristic, however, the number of design applications focusing on the aesthetic characteristic is higher in sportswear.