• Tribology and Lubricants
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• v.12 no.1
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• pp.56-65
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• 1996

The result of wear test for ceramic materials was assessed by Scf parameter to verify the usefulness of the proposed Scf parameter. Friction and wear tests were carried out with ball on disk type. The materials used in this study were HIPed Alumina $(Al_2O_3)$, Silicon carbide (sic), Silicon nitride $(Si_3N_4)$ and Zirconia $(ZrO_2)$. The tests were carried out at room temperature with self mated couples of ceramic materials under lubricated condition. Turbine oil was used as a lubricant. In this test, increasing the load, specific wear rates and wear coefficients of four kinds of ceramic materials had a tendency to increase. The wear coefficients of ceramic materials were in order of $Al_2O_3, SiC, Si_3N_4, ZrO_2$. Worn surfaces investigated by SEM had residual surface cracks and wear particles caused by brittle fracture. As the fracture toughness of ceramic materials was higher, wear resistance more increased. The roughness of worn surface had correlation with wear rate. The wear rate(W$_{s}$) and Scf parameter showed linear relationship in log-log coordinates and the wear equation was given as $W_s = 5.52 $\times$ Scf^{5.01}$.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.6
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• pp.173-179
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• 2009

Recently, the super capacitor(EDLC) which has drawn attention as a new energy storage element has a lot of advantage such as no maintenance, long lifetime and quick charge/discharge characteristics with large current. The objective of this paper is propose a parameter measurement method to detect the changes in equivalent series resistor (ESR) and the capacitance value of a super capacitor in order to analysis the internal characteristic and worn-out state of a super capacitor. For proposed method, only the capacitor voltage measurement using simple analog switch is required. In addition, experimental results of voltage sag compensation system in order to compensate the input voltage drop during short-term power interruption adopted super capacitor are presented.

• Journal of the Korean Society of Clothing and Textiles
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• v.20 no.1
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• pp.142-156
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• 1996

The purposes of this study were to examine the reason, = of clothing discard and to investigate the influences of demographic and clothing variables on the clothing discard behavior Data were collected from 610 women who lived in Seoul and Kwangjoo. By means of factor analysis, 6 general factors of clothing discard reason.; were extracted The 6 factors were named as dissatisfaction with appropriateness, physically worn out, dissatisfaction with clothing quality, fashion change, boredom, inconvinience. Among the five clothing items (suits or one pieces, jackets, jumpers, shirts or blouses, skirts or pants), there existed differences in the reason factors of clothing discard The relationships between clothing discard behavior (reason factors of clothing discard, peviods of clothing utilization) and variables like user's age, degrees of satisfaction with clothing, clothing items were also examined. There existed significant differences among the age groups and the groups classified by clothing satisfaction degrees in the reason factors of clothing discard and in the Periods of clothing utilization. Periods of clothing utilization were also differed by the clothing items. As user's a age grew older, periods of clothing utilization increased and the rates of clothing discard because of dissatisfaction with appropriateness, and dissatisfaction with clothing quality, boredom, inconvinience factors were decreased. As the degrees of satisfaction with clothes increased, the periods of clothing utilization also increased and the rates of clothing discard because of dissatisfaction with appropriateness, and dissatisfaction with clothing quality, inconvinience factors decreased. And the rates of clothing discard because of physically worn out factor increased.

• Journal of the Korean Society of Safety
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• v.15 no.2
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• pp.1-7
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• 2000

This paper presents the approach involving fault detection and diagnosis of gears using pattern recognition and Wavelet transform. It describes result of the comparison between KDI (Kullback Discrimination Information) with the nearest neighbor classification rule as one of pattern recognition methods and Wavelet transform to know a way to detect and diagnosis of gear damages experimentally. To model the damages 1) Normal (no defect), 2) one tooth is worn out, 3) All teeth faces are worn out 4) One tooth is broken. The vibration sensor was attached on the bearing housing. This produced the total time history data that is 20 pieces of each condition. We chose the standard data and measure distance between standard and tested data. In Wavelet transform analysis method, the time series data of magnitude in specified frequency (rotary and mesh frequency) were earned. As a result, the monitoring system using Wavelet transform method and KDI with nearest neighbor classification rule successfully detected and classified the damages from the experimental data.

• The Research Journal of the Costume Culture
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• v.12 no.1
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• pp.73-89
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• 2004

The following is a summary of comparative study on costumes between 『Cheng-Hoe-Jeon-Do』 and 『Chen-De-dang-an』 in Gun-Ryung 41st, 42nd and 43rd yew to find out costume situation actually worn by Emperor Gun-Ryung in Qing dynasty. In Gun-Ryung 41st year, Emperor's costumes showed a sign of royal tour robes. In 42nd year, a phase of mourning robe system came out and a plain side of costumes was shown owing to the mourning. In 43rd year, it showed costume situation worn by Emperor in peaceful year without any particular event. Velvet, material for traveling crown was used in a short time before and after the change of the season besides royal tour and this can be understood as a well-timed and reasonable selection of material. Eventhough robe material, Jik-kyung-Ji-chack-sa(a kind of silk) had been used for summer robes since Gun-Ryung 42nd you. Memorial costumes followed Emperor's court costume system I in 『Cheng-Hoe-Jeon-Do』 and court belt I or II as memorial suit belt was used for the memorial costume of Emperor Gun-Ryung and they properly applied of the costume system in 『Cheng-Hoe-Jeon-Do』 for coats.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.6 no.5
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• pp.439-445
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• 2005

The tribological properties of ceramics are very important in the application to engineering ceramic parts such as seal rings, pump parts, meter parts, and so on. In this study, the effects of each other purity on the mechanical and tribological properties of alumina and zirconia ceramics were investigated. Sliding distance, sliding speed, contact load. friction coefficient, the amount of worn out material at a certain time, and the prepared composites were measured. Crystalline phases and microstructure were examined with XRD and SEM. We obtained the good properties of friction coefficient and wear resistance at the purity 99.7$\%$ of alumina. However, The purity 95$\%$ were great at the wear amount of worn out material.

• Journal of the Korean Society for Heat Treatment
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• v.3 no.2
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• pp.32-36
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• 1990

For the accurate measurements of hardness in a material, it is necessary to have a thorough understanding of the effects of test variables on the accuracy of hardness value. For the rebound hardness test, major test variables are the radius of hammer ball tip, type of backing materials, size and roughness of the specimen. In this study, effects of these variables on Equo-Tip hardness value were investigated. Hardness measurements were carried out using WC balls with various sizes of worn-ot zone. The sample materials chosen for the experiments were commercial standard hardness blocks and SM45C steel bars subjected to either normalization or quench and temper treatments. As backing materials, aluminum, steel and rubber plates were used in all the experiments. Experimental results show that for the accurate measurements of Equo-tip hardness, it is necessary to use the hammer ball with a worn-out zone parameter of less than 0.23, and the recommended minimum thickness and width of the specimen are 25mm and 70mm, respectively. Further for the surface preparation, the specimens need to be polished with an emery paper of No. 400 or finer, and for the backing matrials, it is recommended to use steels or rubbers.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06b
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• pp.271-278
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• 2006

We used polymers of alternating cationic and anionic nature to build up shells on fiber surfaces, strengthen the worn-out fibers and improve paper properties made from such fibers. OCC and ONP pulps were either dipped or salted out in the cationic polyallylamine, polyacrylamide and starch solutions. After centrifugal drying, these were followed by treatments in anionic polyacrylic acid, poly-acrylamide, and starch solutions, respectively. The shell-enhanced fibers were formed into handsheets and their physical properties evaluated. The results show that building multiple shells on worn-out fiber surfaces can strengthen the fibers and paper. The simpler and more practical impregnation-centrifuging treatment provided the desired effects, whereas salting out the polymers produced somewhat superior fibers. The latter process, were impractical, however. The first pair of polymeric shells imparted marked strength improvement, whereas later layers had diminishing efficacies. Overall, the methods can improve fiber quality, attaining paper strength requirements without resorting to expensive measures. Alternate cationic polymer and filler powders were also deposited on fiber surface based on the micriparticle system in an anticipation of stiffness gains. Platy minerals, such as montmorillonite, bentonite, sericite, clay and talc were added following cationic PAM. After dewatering of polymer-pigment shelled fiber of one to 3 pairs of layers, handsheets either calendered or uncalendered were evaluated. The results indicate that regardless of calendaring, stiffness of the handsheets did not improve appreciably while certain other strength properties showed gains. We also attempted the novel starch gel filler addition method wherein tapioca starch and filers (PCC, sericite or clay) were mixed at high solids content of 50% and cooked until gelatinized. The filled handsheets were dried under various conditions and then tested for their properties. Improvements in strengths of modified filled paper were observed.

• Fashion & Textile Research Journal
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• v.20 no.4
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• pp.449-456
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• 2018

This study conducted a survey of members at sports climbing centers on the purchasing and wearing conditions of sports climbing wear and design preferences. 140 participants were in their 20's and 30's, and many of them engaged in sports climbing activities over 20 times a month. They put emphasis on the motion adaptability, durability, price and functional material when purchasing a climbing wear. However, only 23% of them used sports climbing wear. The reasons for wearing sports climbing wears were suitability for physical activity, comfort, and design. On the other hand, the reasons for not purchasing them were expensive prices and lack of designs. They experienced inconveniences at sleeves and waist in shirts. In case of pants, participants experienced inconveniences with the knee and thigh when they climbing. Concerning the damage of shirts, the majority experienced the elbow part was worn out, and the knee part was either worn out or torn at pants. Design preference results showed participants preferred loose-fit short-sleeved shirts that could cover half of the hip. In case of pants, they preferred basic-fit long trousers and basic hems with no functional characteristic. 3 sports climbing instructors answered that climbing wears should put emphasis on deodorization and antimicrobial effects as well as durability and suitability for physical activity. They also pointed out limitations in price and design and presented opinions about creating various sizes for different body parts by taking into account the growth of muscles.

• Journal of the Korean Society of Costume
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• v.56 no.7 s.107
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• pp.1-17
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• 2006

This study purposed to examine Korean people's white clothes custom historically and to explain the aesthetic consciousness latent in the custom. Korean people preferred white clothes, even up to foreigners called them White-clad folk. Not only as in old historical literatures, but also in Soo-suh, Shin-Dang-suh including Sam-Kuk-Ji in China, white clothes were a real symbol to Korean people, ranging chronically far back to the age of ancient tribal countries, Sam-Kuk Period through Koryo Dynasty and even to modern age near the end of Chosun Dynasty, wearing with pleasure regardless of age, sex or social position. Even King himself in Koryo Dynasty is said to have worn white clothes when he was out of official hours. During the Koryo and Chosun Dynasty, white clothes were sometimes prohibited for various reasons including conflicts with the theories of yin-yang and the five elements but such regulations were not effective. To Korean people, white clothes were ordinary people's everyday dress as well as noble people's plain suits, saints' uniforms with religious meanings, ceremonial costumes, funeral garments, etc. The various uses show that white clothes have been worn by many people. The unique custom that a People have worn white clothes consistently for such a long time may contain very deep symbolic meanings representing the people's sentiments and spirits. The present study understood that the meanings come from religious sacredness, magical wish for brightness, the pursuit of purity originating from the people's national traits, assimilation with nature and the will to attain whole ascetic personality. Aesthetic attitudes based on aesthetic values summed up as sacredness, brightness, purity, assimilation with nature, asceticism, etc. are the aesthetic consciousness pursued by Koreans through their white clothes. For Koreans, white color is the origin of their color sense coming from primitive religions such as worshipping the sun and the heaven. In this way, Korean people's preference for white clothes began with primitive religions, was mixed with various social, cultural and religious influences and finally was settled as their durable spirit, symbol and beauty.