• Tribology and Lubricants
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• 제25권4호
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• pp.256-260
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• 2009

Fretting is a kind of wear which effects on reliability and durability. When machine parts are joined joint in parts such as a bolt or a rivet or a pin, fretting phenomenon is occurred by micro relative movement. When fretting occurs in joint parts, there is wear which is the cause of fatigue crack. Recently, although the ways of assessment of fatigue and damage tolerance are established, there is no way to evaluate fatigue crack initiation life by fretting phenomenon. Consequently, the prediction of life and prevention plan caused by fretting are needed to improve reliability. The objective of this paper is to predict fretting wear by using a experimental method and contact analysis considering wear process. For prediction of fretting wear volume, systematic and controlled experiments with a disc-plate contact under gross slip fretting conditions were carried out. A modified Archard equation is used to calculate wear depths from the contact pressure and stroke using wear coefficients obtained from the disc-plate fretting tests.

• 소성∙가공
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• 제33권2호
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• pp.112-117
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• 2024

In this study, the friction and wear characteristics of Inconel 600 in the superplastic forming process of Ti6Al4V were evaluated through pin-on-disc tests. To achieve an efficient and systematic experimental design, the Taguchi method was employed. The wear track of the Inconel 600 pin showed scratches in the sliding contact direction, confirming that the wear mechanism is abrasive wear. Through sensitivity analysis such as ANOVA and Main effects, it was confirmed that both normal force and sliding distance have a significant impact on the wear. Changes in sliding velocity and distance did not affect the friction coefficient, which remained relatively constant at approximately 0.380. The wear prediction model for Inconel 600 in the superplastic forming of Ti6Al4V was constructed, which can be utilized as a guideline for the prediction and management of tool wear.

• 한국생활과학회지
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• 제15권4호
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• pp.585-595
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• 2006

The purpose of this study is to classify the fashion images on sportive style, to find out the difference between the image of sportive style which consumers prefer and the image of sportive style which they want to show and, finally, to analyze their purchase behavior. This research is done with survey method. The subjects of the survey are 835 females in their twenties or their thirties in Pusan area. The data are analyzed with factor analysis, Cronbach's alpha, $X^2$-test, and frequency analysis. The results of this study are as follows: first, sportive style is classified into Sexy, Romantic, Active and Modem image. Second, the results of analysis on consumers' preferring image and their wanting-to-show image to the above-mentioned image classification are as follows: firstly, the subjects' most preferring image and the image which they most want to show is Modem in1age. The second is Sexy image. But the subjects preferred having Modem image. Secondly, consumers' Individuality and apparel's Function are the important reasons to choose the sportive style. Thirdly, Modem image is the most preferred in the images of street wear. Sexy image and Active image are the preferred in the images of sports wear. Third, It is a vivid tone and a dark tone that is the color tone of sportive wear which consumers prefer. They prefer a logo- patterned sports wear, too. The consumers obtain most information on sports wear from sports wear stores. Silhouette is the most decisive design element in consumers' purchasing. The sports wear brands which the subjects prefer are Adidas and Nike.

• 한국의류산업학회지
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• 제18권1호
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• pp.103-112
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• 2016

This research was designed to figure out the perception and attitude of university students toward urban outdoor wear and to provide the guidelines for product quality improvement using Kano model. A total of 270 responses were analyzed by SPSS 20.0 through frequency and factor analysis. Respondents' levels for outdoor activity & outdoor products possession being still low, steady growth in urban outdoor wear market is expected. A total of eight quality factors were identified through factor analysis; suitability, production quality, functionality, ease of care, fabric performance, portability, fashionability, and symbolism. Based on Kano model, quality factors of urban outdoor wear were categorized into three groups: one-dimensional; indifferent; and must-be quality factor. It was found that consumers were satisfied with urban outdoor wear only when it meets the needs for suitability for body types and ease of care, meaning that manufactures should be cautious not to lose these features. Being must-be quality factor, production quality(form stability, quality of subsidiary materials), and fabric performance such as colorfastness should be basically satisfied. The relative importance of each quality feature on satisfaction/dissatisfaction was investigated using CSC(customer satisfaction coefficient). Based on the CSC, every item was classified again. Attractive quality features with large CSC were shown in suitability factor. Must-be quality features with small CSC were mainly shown in functionality and fabric performance factors. These findings imply that manufactures of urban outdoor wear should not only maintain the production quality but also focus on suitability features to differentiate their product with previous products.

• 보존과학회지
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• 제29권1호
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• pp.15-24
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• 2013

울산시 북산동 출토 고려시대 칠사관모(漆紗冠帽)는 복식사적으로 상당히 귀한 유물로 고려시대 당시의 관모형태를 알 수 있어 역사적 문화적 사회적 예술적으로 사료적 가치가 큰 귀중한 자료라고 할 수 있다. 또한 본 유물은 상대적으로 유물이 부족한 고려시대의 실증적 정보를 제공하는 자료로 발굴 작업에 의한 출토품이라는 점에 의의가 있다. 본 연구에서는 오랜 시간동안 다양한 환경요인에 의해 영향을 받아온 유물의 보존처리를 통해 본래의 상태로 회복시키고 원형을 보존하고자 하였다. 그 결과, 실존유물이 상대적으로 부족한 고려시대 관모의 원형을 보존할 수 있었으며, 재질 및 구조분석을 통해 섬세한 사(紗)조직의 표면조직과 죽사(竹絲)로 제작된 바탕조직을 확인할 수 있었다.

• Tribology and Lubricants
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• 제35권3호
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• pp.183-189
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• 2019

The driver seat of an automobile is in direct contact with the driver and provides the driver with a safe and comfortable ride. The seat consists of a frame, a rail, and many recliners. In recent years, strength and operating force measurement testing of the recliner have become vital for designing car seats. However, performance evaluation requires expensive testing equipment, numerous seat products, and considerable time. Therefore, the trend is to reduce experimentation through interpretation. This study examines the lubrication of solid lubricant for automotive seat recliners and confirms the friction and wear performance. In this study, the lubrication behavior of solid lubricants for car seat recliners is investigated to ascertain the friction and wear performance and to provide accurate values for the strength analysis. The friction material consists of a pin and a plate made from steel, which is widely used in recliners. The friction and wear under lubrication conditions are measured by a reciprocating friction wear tester. The friction coefficient is obtained according to the load and speed. Based on the obtained results, it is possible to achieve a reduction in the error of the test value and the analysis by providing the friction coefficient and wear of the lubricant. The results can be applied to the analysis of automobile seat design.

• Tribology and Lubricants
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• 제22권3호
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• pp.155-163
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• 2006

Ring, groove and cylinder bore wear may not be a problem in most current automotive engines. However, a small change in ring face, groove geometry and cylinder bore diameter can significantly affect the lubrication characteristics and ring axial motion. This in turn can cause to change inter-ring pressure, blowby and oil consumption in an engine. Therefore, by predicting the wear of piston ring face, ring groove and cylinder bore altogether, the changed ring end gap and the changed volume of gas reservoir can be calculated. Then the excessive oil consumption can be predicted. Being based on the calculation of gas flow amount by the theory of piston ring dynamics and gas flow, and the calculation of oil film thickness and friction force by the analysis of piston ring lubrication, the calculation theory of oil amount through top ring gap into combustion chamber will be set. This is estimated as engine oil consumption. Furthermore, the wear theories of ring, groove and cylinder bore are included. Then the each amount of wear is to be obtained. The changed oil consumption caused by the new end gap and the new volume of oil reservoir around second land, can be calculated at some engine running interval. Meanwhile, the wear amount and oil consumption occurred during engine durability cycle are compared with the calculated values. Next, the calculated amount of oil consumption and wear are compared with the guideline of each part's wear and oil consumption. So, the timing of part repair and engine life cycle can be predicted in advance without performing engine durability test. The wear data of rings, grooves and cylinder bore are obtained from three engines before and after engine durability test. The calculated wear data of each part are turn out to be around the band of averaged test values or a little below.

• 대한치과보철학회지
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• 제38권4호
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• pp.438-445
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• 2000

The ideal restorative material should mimic the properties of the tissues it replaces. Dental composite resins have been used widely as restorative materials due to its advantages such as excellent esthetics and ease of manipulation. But inadequate wear resistance has been a major factor limiting the use of composite restorative materials. Improved manufacturing techniques have allowed the development of hybrid composites, with a greater percentage volume filler loading, which have improved physical and mechanical properties. However they are lacking in the study of wear resistance. The purpose of this study was to evaluate the wear of human enamel against ceromer by the use of a pin-on-disk type wear testers. Discs of ceromer(Targis ; lvoclar Vivadent, Amherst. NY) and discs of type III gold alloy as a control were used f9r test specimens. Intact cusp of premolar and molar were used for enamel specimens. The wear of enamel was determined by weigh-ing the cusp before and after each test, and the weight converted to volumes by average densi-ty of enamel. Surface profilometer was used to quantify wear of the ceromer and gold specimens. Vicker's hardness tester was used to evaluate the surface hardness of test specimens. The SEM was used to evaluate the wear surfaces The results were as follows; 1. Ceromer produced less enamel wear than gold(p<0.05) 2. The wear volume of ceromer was greater than that of gold(p<0.01) 3. The hardess of ceromer was lower than that of gold, but there was no correlation between the hardness and wear of the ceromer and gold. 4. SEM analysis revealed that there were many voids and microcracks in the wear tract of ceromer In gold group, many minute V-shaped grooves were examined.

• 한국의류학회지
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• 제25권6호
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• pp.1122-1130
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• 2001

Recently the importance of distribution channel design has been focused on due to a turbulent environment. The channel design strategy involves the choice of an optimal channel arrangement including channel width, channel depth, the types of intermediaries to be used, and the specific responsibilities of each channel member. The purpose of this paper is to investigate changes of distribution intensity in the infant & children's wear brand from 1997 to 1999, when Korea has faced changes before and after IMF intervention that influenced the Korean economy greatly. Thus, this study provides channel managers with some guidelines for establishing and adjusting the infant & children's wear channel strategies. The data is collected by the Korean Fashion Brand Annual published by Apparel News Co., from 1997 to 1999. infant & children's wear brands are selected and analyzed with Pearson correlation. Statistic analysis has shown different results in the type of brands in terms of distribution intensity. The type of brands between infant's wear and those for children differ in price and launching period. In the case of infant's wear brands, the launching period and total sales should be considered in designing channel distributions, while for children's brands total sales are significant. As the price increases, children's wear brands are significantly linked to their distribution intensity only in certain times at the starting point of IMF intervention. IMF intervention do not seem to influence the distribution intensity of infant's wear brands much as it did children's wear brands. It seems that the infant's wear industry is more stable than the children s wear industry. As a result, the marketer who plans distribution intensity for the infant's and children's wear brands should consider total sales, the launching period and the price according to the type of brands he deals with.

• 한국구조물진단유지관리공학회 논문집
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• 제14권4호
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• pp.86-93
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• 2010

레일마모는 열차의 주행안전 및 승차감에 미치는 영향이 크고, 소음 진동의 주요원인으로 작용한다. 또한 레일마모가 발생할 경우 궤도구조의 파괴를 촉진시킴으로써 차량 및 궤도유지보수비를 크게 증가시킨다. 따라서 현장에서 발생하는 마모 원인을 체계적으로 분석함으로써 마모를 저감할 수 있도록 차량운행 조건과 선로선형 및 궤도구조를 설계하는 것은 중요한 과제이다. 본 연구에서는 궤도의 효율적인 유지관리를 위해 궤도를 구성하고 있는 레일, 체결구, 침목, 도상 등의 요소를 고려하여 레일 궤도의 생애주기 거동 및 유지관리 특성을 분석하였다. 또한 축적된 진단/검측 데이터로부터 궤도 구성품의 건전도를 평가할 수 있는 방법을 정립하고 잔존수명을 예측하여 효율적 유지관리를 실현할 수 있는 기법 개발을 위하여 지하철 레일단면마모데이터를 이용한 구간 특성에 따른 시간-마모량의 확률적 분포 변화와 다중회귀 분석을 수행하였다.