• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1999년도 제30회 추계학술대회
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• pp.19-24
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• 1999

Understanding of wear mode and prediction of wear rate of parts in sliding contact are very important in field of meterial design relating with wear resistant. This paper has been undertaken to analyze the possibility of elucidation of wear mode and prediction of wear rate for annealed steel in sliding contact using the X-ray diffraction. The sliding wear test with various velocities using pin-on-disc machine and the X-ray diffraction test on the worn surface have been carried out. The results have been shown that the magnitude of residual stress and half-value breadth on the worn surface have a good correlation with wear mode. The difference between before and after test of half-value breadth on worn surface has been shown to be exponential relation with wear rate in the same wear mode.

• 한국의류학회지
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• 제24권6호
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• pp.838-849
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• 2000

The purpose of this study was to investigate use and purchase behavior of sleeping wear for summer. Subjects in this study were composed of 591 males and females aged from twenties to fifties, living in Taejon and Chongju. For data analysis, descriptive analysis, $\chi$$^2$-test, t-test, ANOVA, and factor analysis were used. The results are as follows. First, subjects used sleeping wear(a night gown and pajamas), and home wear(T-shirts and sweat suit with zippered top) with similar rates. The subjects, who are females, married, older and have professional jobs, owned sleeping wear such as a night gown and pajamas more than home wear. Also, the mean of using pajamas was the highest, and they were satisfied with them more than others who didn't wear them. Second, one-third of consumers purchased sleeping wear once a year in a specialty store. Consumers mainly searched for information regarding sleeping wear in the display section. Most consumers weren't influenced by others when they made their purchases. When consumers decided to purchase a product, they considered six criteria such as fabric/management, wearing/fitness, esthetic, service, symbolic status, and economic for evaluating. Among them, the factor wearing/fitness was considered the most important. These results imply that consumers would be conscious of sleeping wear even though sleeping wear and home wear are used interchangeably. In addition, consumer behavior concerning sleeping wear is different from their characteristics such as sex, age, occupation, the level of education, and marital state. Therefore, the markets with sleeping wear would be able to be segmented based on consumers’characteristics. Also, marketers should focus on distribution channels to reform the markets of sleeping wear, that is, they may offer products in specialty stores. Additionally, market managers would be able to concentrate on visual merchandising in stores in order to increase brand awareness and market share.

• Journal of Mechanical Science and Technology
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• 제20권12호
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• pp.2052-2060
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• 2006

The wear of engine valve and seat insert is one of the most important factors which affect engine performance. Because of higher demands on performance and the increasing use of alternative fuel, engine valve and seat insert are challenged with greater wear problems than in the past. In order to solve the above problems, a simulator was developed to be able to generate and control high temperatures and various speeds during motion. The wear simulator is considered to be a valid simulation of the engine valve and seat insert wear process with various speeds during engine activity. This work focuses on the different degrees of wear at three different singular test speeds (10 Hz, 25 Hz & multi-Hz). For this study, the temperature of the outer surface of the seat insert was controlled at 350$^{\circ}C$, and the test load was 1960 N. The test cycle number was $6.0{\times}10^6$. The mean ($\pm$standard error) wear depth of the valve at 10 Hz and 25 Hz was 45.1 ($\pm$3.7)$\mu$m and 81.7 ($\pm$2.5)$\mu$m, respectively. The mean wear depth of the seat insert at 10 Hz and 25 Hz was 52.7 ($\pm$3.9)$\mu$m and 91.2 ($\pm$2.7)$\mu$m, respectively. In the case of multi-Hz it was 70.7 ($\pm$2.4)$\mu$m and 77.4 ($\pm$3.8)$\mu$m, respectively. It was found that higher speed (25 Hz) cause a greater degree of wear than lower speed (10 Hz) under identical test condition (temperature, valve displacement, cycle number and test load). In the wear mechanisms of valves, adhesive wear, shear strain and abrasive wear could be observed. Also, in the wear mechanisms of seat inserts, adhesive wear, surface fatigue wear and abrasive wear could be observed.

• 한국콘텐츠학회논문지
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• 제16권2호
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• pp.609-617
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• 2016

본 연구는 대학생들이 사용하고 있는 칫솔의 마모도와 마모율을 평가하고 관련요인을 파악하여 대학생 구강보건교육 자료로 활용하고자 하는데 목적이 있다. 2015년 3월 16일부터 4월 10일까지 573개의 칫솔을 수거한 뒤 칫솔 마모도를 평가하여 다음과 같은 결과를 얻었다. 칫솔 마모도는 조사 대상 칫솔 중 46.9%가 0.400 이상의 마모도를 보였고, 평균 마모도는 $0.403{\pm}0.20$로 조사되어, 전체적으로 높은 칫솔 마모도를 보였다. 칫솔 마모율은 1점과 2점이 차지하는 비율이 70.4%였으며, 평균 마모율은 $1.620{\pm}0.74$로 나타나 전체적으로 높은 칫솔 마모율을 보였다. 성별에 따른 칫솔 마모도 및 마모율은 남학생이 여학생보다 높았으며, 칫솔교체주기가 길수록 칫솔 마모도와 마모율 모두 유의하게 높았다. 대학생들의 칫솔교체 주기 및 칫솔 관리가 적절히 이루어질 수 있도록 올바른 칫솔관리에 대한 효율적인 구강보건교육 방안을 마련하는 것이 필요하다.

• 복식
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• 제52권2호
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• pp.139-150
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• 2002

The purpose of this study was to explore the effects of meteorological factors on sales of apparel products. Basic fiat came out daily meteorological data and sales data of apparel products in department store from 1998 to 2000. Four factors(the average temperature, rainfall, wind velocity, sunshine duration) from the nine meteorological factors were selected and were collected with Korea Meteorological Administration. Sales data were collected with business strategy department of H (department store in Seoul. The sales data were divided into six classifications, which are woman's wear, men's wear, children's wear, golf wear, sports wear, and inner wear. The results of this study were as follows: 1) Sales of apparel products were significantly correlated with the average temperature, rainfall, wind velocity, sunshine duration. Among the meteorological factors, temperature turned out to be the most influential in apparel sales and then the amount of rainfall, sunshine duration affected sales according to apparel classifications differently. 2) There were some differences among the apparel classifications in the effect of meteorological factors on the sales of apparel. In the spring. the higher the temperature was, the higher the sales of women's wear and golf wear were, but the lower the sales of children's wear, sports wear and inner wear were. In the summer, The higher the amount of rainfall was, the lower the sales of all the apparel classification were. The higher the temperature was, the higher the sales of sports wear were. In the fall, the lower the temperature was, the higher the sales of all the apparel classification except snorts wear were. In the winter, the meteorological factors had little effect on the sales of women's wear, men's wear and children's wear. The higher the temperature was, the higher the sales of golf wear were. The lower the temperature was, the higher the sales of sports wear were.

• 한국의류산업학회지
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• 제14권5호
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• pp.846-852
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• 2012

Pets (such as dogs) are considered as important as family members, this perspective is due to an aging population and the decreased size of the traditional nuclear family. The pet industry has been growing every year; subsequently, is useful to develop practical patterns and designs appropriate for the body structure and movement of pet dogs. However, studies to develop a new form of pet dog's wear patterns and designs are limited. This study develops a basic pattern that is easily used based on a pet dog's size, designs popular clothing items for pet dogs, and helps in the manufactures of pet dog's wear. The results are as follow: 1) Analyzed categories and popular items of pet dog's wear from the research of the prior studies and on-line pet dog shopping malls; three categories (everyday wear, street wear, and special wear) and six items (T-shirt, one-piece, coat, jumper, and dress, tuxedo). 2) Developed the basic bodice pattern and sleeve pattern after test-wearing and revising the experimental patterns referenced from prior studies. 3) Developed patterns and designs for six popular items based on situation and gender: one-piece (everyday wear), coat (street wear), wedding dress (special wear) for female dogs/T-shirt (everyday wear), hood jumper (street wear), tuxedo (special wear) for male dogs. 4) Developed the previous six items to illustrate the research results of the study.

• Tribology and Lubricants
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• 제13권1호
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• pp.42-52
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• 1997

This paper deals with wear characteristics of ion-nitrided metal theoretically and experimentally in order to analysis of wear phenomena. Wear tests show that compound layer of ion-nitrided metal reduces wear rate when the applied wear load is mall. However, as th load becomes large, the existence of compound layer tends to increase wear rate. The residual stress at the surface of ion-nitrided metal is measured, and the internal stress distribution is calculated when the normal and tangential forces are applied to the surface of metal. Compressive residual stress is largeest at the compound layer, and decreases as the depth from the surface increases. Calculation shows that the maximum stress exists at a certain depth from the surface when normal and tangential force are applied, and that the larger the wear load is the deeper the location of maximum stress becomes. In the analysis, it is found that under small applied wear load the critical depth, where voids and cracks may be created and propagated, is located at the compound layer, as the adhesive wear, where hardness is an important factor, is created the existence of compound layer reduces the amount of wear. When the load becomes large the critical depth is located below the compound layer, and delamination, which may be explained by surface deformation, crack nucleation and propagation, is created, and the existence of compound layer increases wear rate.

• KSTLE International Journal
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• 제10권1_2호
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• pp.33-36
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• 2009

The nuclear steam generator is composed of a bundle of tubes. The length of these tubes is very long, but their diameter is small. Fluid exists inside of the steam generator and its flow causes vibration, therefore these tubes are supported by anti-vibration bars. The wear damage due to the vibration is known as fretting wear, which should be minimized to ensure the safety of the plants. Research needs to be done about decreasing the amount of fretting wear. Hard coatings have proven to be very effective in reducing the amount of wear. The commercial coatings of TiN and CrN have excellent wear resistance and are used to protect the Inconel tube from fretting wear. The tube-on-flat type tester was used for conducting the fretting wear tests. It was found that the wear amounts of the coated tubes decreased depending on the coating thickness. CrN was found to be very effective in reducing the wear, while the wear amounts were dependent on the coating thickness in the case of TiN and a thick coating of TiN was very effective on wear resistance.

• 소성∙가공
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• 제20권7호
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• pp.479-484
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• 2011

Dry sliding wear behavior of AISI 52100 steel that has a pearlite or bainite microstructure was characterized to explore the effect of microstructure on the wear of the steel. Isothermal heat treatments were employed to obtain the different microstructures. Pin-on-disk type wear tests of the steel disk were performed at loads of 25~125N in air against an alumina ball. Sliding speed and wear distance used were 0.1m/sec and 300m, respectively. Worn surfaces, wear debris and cross-sections of the worn surfaces were examined with SEM to investigate the wear mechanism of the steel. Hardness of the steel was also evaluated. Wear rate of the steel was correlated with the hardness and the microstructure. On the whole, wear resistance increased with an increase in hardness. However, the pearlite microstructure showed superior wear resistance as compared to the bainite microstructure with a similar hardness. The effect of the microstructure on the wear rate was attributed to the morphological differences of the carbide in the microstructure, which was found to have a significant effect on strain hardening during the wear.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1996년도 추계학술대회논문집
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• pp.122-130
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• 1996

During the cold forming, due to high working pressure acting on the die surface, failure mechanics must be considered before die design. One of the main reasons of die failure in industrial application of metal forming technologies is wear. Die wear affects the tolerances of formed parts, metal flow and costs of process etc. The only way to control these failures is to develop methods which allow prediction of die wear and costs of process etc. The only way to control these failures is to develop methods which allow prediction of die wear and which are suited to be used in the design state in order to optimize the process. In this paper, the wear experiments to abtain the wear coefficients and the upsetting processes was accomplished to observe the wear phenomenon during the cold forming process. The analysis of upsetting processes was accomplished to observe the wear phenomenon during the cold forming process. The analysis of upsetting processes was accomplished by the rigid-plastic finite element method. The result from the deformation analysis was used to analyse the die wear during the processes and the predicted die wear profiles were compared with the measured die wear profiles.