• International Journal of Fluid Machinery and Systems
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• 제2권1호
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• pp.21-30
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• 2009

Slurry wear with sand particles in rivers is a serious problem for pump operation. Therefore, a technique to predict wear volume loss is required for selecting wear resistant materials and determining specifications for the maintenance period. This paper reports a method for predicting the wear depth distribution on the blade of an impeller. Slurry wear tests of an aluminum pump impeller were conducted. Prediction results of wear depth distribution approximately correspond with the results of slurry wear tests. This technique is useful for industrial application.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1607-1612
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• 2007

It necessarily follows that wear particles are generated through a friction and wear in a mechanical moving system. The wear particles are relative to the failure and the life of machine elements directly. To analyze the wear particle, its shape characteristics were calculated quantitative values such as diameter, roundness and fractal parameters by digital image processing. In this study, the histograms of shape parameters of wear particles were used for the purpose of analyzing the distribution of wear particles in various conditions. We consider that the histogram of shape parameter can be effectively represented to study a wear mechanism.

• Tribology and Lubricants
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• 제23권1호
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• pp.29-36
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• 2007

It necessarily follows that wear particles are generated through a friction and wear in a mechanical moving system. The wear particles are relative to the failure and the life of machine elements directly. To analyze the wear particle, its shape characteristics were calculated quantitative values such as diameter, roundness and fractal parameters by digital image processing. In this study, the histograms of shape parameters of wear particles were used for the purpose of analyzing the distribution of wear particles in various conditions. We consider that the histogram of shape parameter can be effectively represented to study a wear mechanism.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1994년도 추계학술대회 논문집
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• pp.73-78
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• 1994

Wear and fracture mode of ceramic tool for hardened SKD11 steel was investigated by face milling in this study. The cutting force and Acoustic Emission(AE) signal were utilized to detect the wear and fracture of ceramic tool. The following conclusions were obtained : (1) The wear and fracture modes of ceramic tool are characterized by three types: \circled1wear which has normal wear and notch wear, \circled2 wear caused by scooping on the rake face, \circled3 large fracture caused by thermal crack in the rake face. (2) The wear behaviour of ceramic tool can be detected by the increase of mean cutting force and the variation of the AE RMS voltage. (3) The catastrophic fracture of ceramic tool can be detected by the cutting force(Fz-component). (4) As the hardness of work material increased, Acoustic Emission RMS value and mean cutting force(Fz) increased linearly, but the tool life decreased.

• 대한기계학회논문집A
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• 제32권11호
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• pp.963-969
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• 2008

The wear particles are relative to the failure and the life of machine elements directly. But it is not laid down to calculate shape parameters of wear particle. To analyze a variation of distributed characteristics of wear particles on moving conditions, its shape parameters such as diameter and roundness were calculated the quantitative values by digital image processing, and had to be defined the effective method of using those data. Up to the present, the shape parameters have been used simply into the average values. But these values are not effective to analyze a variation of distributed characteristics of occurred wear particles on moving conditions. In this study, the relative histograms of shape parameters of wear particles were used for the purpose of analyzing the distribution of wear particles in various conditions. The results showed that the relative histogram of shape parameters can be effectively represented to study a wear mechanism.

• Tribology and Lubricants
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• 제17권4호
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• pp.335-340
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• 2001

It was reviewed that the kinds of lubricating oil, viscosity, temperature and strength of materials affected the wear of the surface heat treatment. When lubricants is used under severe running conditions, their tribological characteristics are very important. We have studied the lubricating oil viscosity, kinds of additives and their amounts, and lubricating oil temperatures were changed. In order to study the effect of oil temperature on the wear of the surface, the temperature of the oil was changed for the same sample. It was shown from the test results that wear is not greatly affected by the amount of ZnDTP (Zinc dialkyl dithio phosphate) antiwear agent, but EP (Extreme pressure) additives are less effective against wear than ZnDTP additives. The viscosity of lubricating oil and its temperature greatly affect the wear of the surface. Combining all the wear data with those of the surface strength, it was observed that the higher the load, the lower the scratch of wear, and also in the case of the same running load, the lower the wear, the longer the life of the surface strength.

• 복식
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• 제44권
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• pp.37-56
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• 1999

In clothing, a tendency of Bisexuality is in case of wearing clothing of the opposite sex, the mixing of modeling principle and characteristic of man and woman, the exclusion characteristic of sexuality that present sexlessness-the third sex. They-Designer Gabrielle Chanel, YSL, Giorgio Armani-give characteristic of man's fashion to women's fashion. However, the consciousness in design is different. Chanel apply principle of man's suit to woman's wear to express authority and power about gender image, hereby she express women liberation and equality of man and woman based on social ideology through fashion especially, she express women's sexual independency and self assurance to her clothing. YSL express liberal and bold women that pursuit reasonal and liberal life in 1970. As he apply tailoed suit's rigidity to women's wear, he made 'pants look' universal in women's wear through“Dress for success”in modern life. Armani apply successful modern image to women's wear, so he express women's image of confident intellegent as well as feminine image. He focus women's new image as man living liberal and indivisual life excluding social category rather than will of equality of man and women. Gernreich break sexual prejudice and release women freely, furthermore, as he express concern of sexuality pursuit liberty of mankind surpassing sex distinction with women liberty. Gianni Versace pursuit mix and extinguishment of sexual image many-sided, and break fixed idea of sex, and reprovide feminine and masculine image. So his design tend homosexuality because he regard women's glamor and ostensible sexuality as standard of beauty, he apply this to man's wear as well as women's wear. With this, he expresses sensitive and liberal man's that break characteristic of Gender that symbolize power and authority in man's wear through 'Without ties'.

• 한국표면공학회지
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• 제52권1호
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• pp.16-22
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• 2019

The structural change of DLC coatings during long-term wear test and dicing test under the low loading condition was investigated. DLC coatings were applied for the precision injection molds of a modified SNCM steel for the extension of life and the micro-diamond blades for the high cutting efficiency and the increase in life. A ball-on-disc wear tests in the mold steel and a dicing tests in the micro-diamond blades were conducted to understand degradation of DLC coatings. The degradation of DLC coatings for the injection mold steel and the micro-diamond blades during the wear and dicing tests were studied with Raman Spectroscopy. Raman peaks were divided two bands(D band and G band) to study the degradation process of DLC structure. By the wear test, polished condition of wear marks were observed to be maintained until 10 hrs of wear test period is given, but small striation marks appeared in 20 hours wear test. It was observed that $I_D/I_G$ ratios changed as the degradation of DLC coatings is proceeded during the wear tests and the dicing tests. It is suggested that the change in $I_D/I_G$ value possibly reflected from the composition of $sp^2$ and $sp^3$ bondings in DLC layers relevant to the change in mechanical and physical property.

• 한국의상디자인학회지
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• 제12권2호
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• pp.91-105
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• 2010

The purposes of this study were to segment consumers by life style groups and to investigate the differences among the segmented groups in regard to Korean image preferences in casual wear. The subjects of the study were 653 women consumers who lived in Seoul. Data were collected from July to September, 2007. Statistical analyses used in the study were factor analysis, cluster analysis, ANOVA, and Scheffe test. The results showed that there were seven factors of life style: fashion and appearance interest, pride in Korea, sociability, interest in foreign culture, family centered, sports/culture, and interest in Korean food. Based on the seven factors, the consumers were segmented into three groups. They were fashion/diverse culture interest group, family/recreation oriented group, and sociability/family oriented group. The results showed that there were significant differences among the lifestyle segmented groups in regard to Korean image preferences for color, fabric, pattern, and categories of casual wear, and the intention to purchase the casual wear. For example, fashion/diverse culture interest group preferred diverse Korean prints, red, orange, blue and white colors, natural fabrics, and various types of casual wear. Also, the group has the highest interest and intention in wearing Korean image casual wear.

• 한국컴퓨터정보학회논문지
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• 제22권5호
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• pp.1-9
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• 2017

Recently, flash memory has been in a great demand from embedded system sectors for storage devices. However, program/erase (P/E) cycles per block are limited on flash memory. For the limited number of P/E cycles, many wear leveling techniques are studied. They prolonged the life time of flash memory using information tables. As one of the techniques, block erase table (BET) method using a bit array table was studied for embedded devices. However, it has a disadvantage in that performance of wear leveling is sharply low, when the consumption of memory is reduced. To solve this problem, we propose a novel wear leveling technique using Sampling-based Block Erase Table (SBET). SBET relates one bit of the bit array table to each block by using exclusive OR operation with round robin function. Accordingly, SBET enhances accuracy of cold block information and can prevent to decrease the performance of wear leveling. In our experiment, SBET prolongs life time of flash memory by up to 88%, compared with previous techniques which use a bit array table.