• Title/Summary/Keyword: Wear characteristic

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Evaluation of Mechanical Characteristic and Residual Stress for Railway Wheel (철도차량 차륜의 기계적 특성 및 잔류응력평가)

  • Seo, Jung Won;Kwon, Suk Jin;Lee, Dong Hyeong;Jun, Hong Kyu;Park, Chan Kyeong
    • Journal of the Korean Society for Precision Engineering
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    • v.31 no.9
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    • pp.783-790
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    • 2014
  • Railway wheels and axles are the most critical parts of the railway rolling stock. The wheel carry axle loads and guide the vehicles on the track. Therefore, the contact surface of wheel are subjected to wear and fatigue process. The wheel damage can be divided into three types; wear, contact fatigue failure and thermal crack due to braking. Therefore, in the contact surface between the wheel and the rail, the materials are heat treated to have a specific hardness. The manufacturing quality of the wheel have a considerable influence on the formation of tread wear and damage. Also, the residual stress on wheel is formed during the manufacturing process is one of the main sources of the damage. In this paper, the mechanical characteristic and the residual stress according to wheel material have been evaluated by applying finite element analysis and conducting mechanical tests.

The Purchasers vs. Non-Purchasers of Performance Infants' Wear: Shopping Behavior, Shopper Characteristics, and Reasons for Purchase/Non-Purchase (기능성 섬유 유아복 구매자와 비구매자간의 구매 행동 및 구매 특성 비교)

  • Hong Kyung-Hee;Lee Yoon-Jung
    • The Research Journal of the Costume Culture
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    • v.13 no.6 s.59
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    • pp.1023-1036
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    • 2005
  • The heightened consumers' interest in health and well-being gave rise to the needs for performance infants' wear, which are made with environmentally-friendly and healthy functional materials. This study intends to compare purchasers and non-purchasers of performance infants' wear in terms of their shopping behavior, shopper and infants' characteristics, and reasons for purchasing or not purchasing performance infants' wear. A total of 241 questionnaires were collected from women with infants less than 4 years old, who are living in the Seoul metropolitan area. Using SPSS 10.0, chi-square, paired t-test, and descriptive statistics were calculated to analyze the data. The results of the study were as follows: First, the purchasers of performance infants' wear shopped more often at department stores and were more likely to buy comparatively high-price products than non-purchasers. Second, for performance infants' wear, non-purchasers considered laundry/care methods and fiber contents more, while purchasers considered colors, design, price, and performance of the products less than for infants' wear in general. Third, in terms of demographic characteristics, significant differences were found for the number of children and the child's birth order. Fourth, the primary reason for buying performance infants' wear was 'health'. The primary reason for not buying was 'too high price' and 'lack of information'. The 'high price compared to its performance' and 'lack of color choice' were among the purchasers complaints about performance infants' wear.

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A Study on the Techniques of Expression of Modern Knitwears - Focusing on the Collection's Books of 1990's After - (현대(現代)니트의 표현기법(表現技法)에 관(關)한 연구(硏究) - 1990년대(年代) 이후(以後)의 Collection지(誌)를 중심(中心)으로 -)

  • Choi, Kyung-Hee
    • Journal of Fashion Business
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    • v.4 no.3
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    • pp.115-129
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    • 2000
  • The purpose of this study is to discover the techniques and the trends of expression of modern knitwears focusing on the 1990's after. The resorts of this study is as follows: The techniques of expression of knitwears are classified by the sections on the techniques and the styles of expression. The divisions into the techniques are knitting, crochet, macrame, netting, knotting. And the divisions into upon the styles of expressions are color, pattern, texture, relief and seeing through The techniques of expression on the modern knitwears are expressed characteristic of variety and composition, are expended to the art wear by translated into art. According to a wide sense, ecology, ethnic, modern are the themes of knitwears of 1990's after. The characteristic technique of expression according to the themes are expressed by the harmony of image, yarn, color, silhouette, techniques of expression. The modern knitwears are tried by mixed and various techniques, developed to the area of art wear, escaping from simple and practical item.

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Machining characteristic of gray cast iron in high speed machining with tungsten carbide endmill (초경 엔드밀에 의한 회주철(GC250)의 고속가공 특성(1))

    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.10a
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    • pp.147-150
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    • 1995
  • High speed machining one of the most effectiv to improve machining accuracy and product in dies and mould. But a study on this is limited to Alumium, light metal etc. This paper presents machining characteristic of gray cast iron in high speed machining with tungsten carbide endmill. It is suggested to measure sutting force, tool wear, surface roughness, surface shape and select of cptimal cutting condition in the high speed machining of gray cast iron. Performance of high speed machine tool was estimated and the relationship between cutting phenomenon and machinabillity was described.

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The Appearance of the Ready-to-wear Clothing in the West and Its Utopian Characteristics (서양 기성복의 출현 배경과 그 유토피아적 성격)

  • Kim, Yoonhee
    • Journal of the Korean Society of Costume
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    • v.64 no.3
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    • pp.155-164
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    • 2014
  • This paper discusses the social changes in the late 19th century that provided a historical background in the appearance of the ready-to-wear clothing in the West. It examines the social meanings of the appearance of the ready-to-wear clothing at the time and traces the origins of these social characteristics to the book published in the $16^{th}$ century by Thomas More, Utopia. The results of this study can be summarized as the following. First, the appearance and expansion of the ready-to-wear clothing coincided with the social transition from a class-based society to a democratic society in the west in the $19^{th}$ century. Second, uniforms were produced in the $18^{th}$ century Europe in order to distinguish different classes and ethnic groups, with the military uniforms being the most visible example. Frequent military campaigns in Europe resulted in the increasing demand and expansion of military uniforms, which later became the basis of the standardization of the men's clothing with uniforms. Third, the women's ready-to-wear clothing appeared later than their male counterpart and was made possible by the simplification of design, an important characteristic of women's wear in the later period. Fourth, the social characteristics of the ready-to-wear clothing can be traced to a democratic and egalitarian society without personal properties that was depicted in the book of Utopia by Thomas More. Fifth, one of the characteristics of the ready-to-wear clothing can be found in the description of Utopia, in which everyone in Utopia wears a clothing of the same form for life.

A Study on the Development of Cu Free Friction Material of Composite Brake to Response Eco-friendly Regulation (친환경 법규 대응을 위한 복합재 브레이크의 Cu Free 마찰재 개발에 관한 연구)

  • Shim, J.H.;Lee, J.H.;Shin, U.H.;Lim, D.W.;Hyun, E.J.
    • Journal of Auto-vehicle Safety Association
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    • v.14 no.2
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    • pp.90-95
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    • 2022
  • Composite material is widely used in the automotive industries because it has excellent mechanical properties and is possible to reduce weight due to the low density. However, there is a new obstacle to meet environment regulation like Cu less or Cu free regulation for the friction material. Although it is strongly demanded, there are few research results about that unfortunately. Unless this problem is not solved properly, it is impossible to apply composite brake system to vehicle. In this paper, a new eco-friendly friction material for composite brake system is represented to respond these regulations. To do this, friction characteristics between existing low steel friction material and new eco-friendly friction material are verified to secure performances for brake system such as effect characteristic, fade characteristic and wear characteristic. And composite brake gets the equivalent or better performance compared to a low steel friction material. Finally, this result contributes to the study of major principles for the development of eco-friendly friction material in the future.

The Effect of Hue, Tone, and Necktie Width on Men's Wear Image (색상과 톤, 넥타이 폭이 남성복 이미지에 미치는 영향)

  • Jeong, Su-Jin;Choi, Su-Koung
    • Journal of the Korea Fashion and Costume Design Association
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    • v.12 no.3
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    • pp.33-42
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    • 2010
  • The purpose of this study was to investigate the effect of hue, tone, and necktie width on men's wear image. The experimental materials developed for this study were a set of stimulus and response scales. The stimuli were 12 color pictures, in which the hue(red, blue), tone(lt-shirt/dk-tie, dk-shirt/lt-tie), and necktie width(narrow, medium, width) were manipulated. The 7-point scale was used for evaluation of men's wear image. The subjects of this research were 120 female college students living in Seoul, Gwangju, Jinju, and Masan. The investigation was carried out at April-May 2009. The data were analyzed by using SPSS program. Analysis methods were ANOVA and Duncan-test. The results of this study were as follows.; The analyses of men's wear image according to hue, tone, and necktie width revealed that the concerned factors are four characteristic dimensions of ability-elegance, attractiveness, appeal-activity, and warmness. Hue showed an independent effect on ability-elegance, appeal-activity, and warmness. Tone showed an independent effect on warmness. Necktie width showed an independent effect on appeal-activity. In addition, interaction effects of hue and tone on ability-elegance were found. Interaction effects of hue and necktie width on ability-elegance and attractiveness were found.

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An Analysis on the Variation of the Wheel/Rail Contact Geometry with the Wheel Wear of EMU (전동차 차륜 마모에 따른 차륜/레일 기하학적 접촉 특성 변화 분석)

  • Hur, Hyun-Moo;Park, Joon-Hyuk;You, Won-Hee;Park, Tae-Won
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.854-859
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    • 2008
  • In a railway vehicle, contact between wheel and rail is a peculiar characteristic and variations of wheel and rail profile influence on the dynamic characteristics of railway vehicle. Thus the variations of the wheel and rail profile are very important in railway dynamics. Recently a research relating to active steering to improve the curving performance of vehicle is progressing actively at home and abroad. In this field, a pre-study for the wheel/rail contact geometry is needed and especially the variation of the wheel/rail contact geometry with wheel wear is the key design parameter to develop the controller of the active steering bogie. In this paper, we have experimentally studied to analyze the variation of the wheel/rail contact geometry with wheel wear as a pre-study to develop the active steering bogie for electric multiple unit (EMU). For this, we have made an experiment with EMU operating in curving area. We have measured the wear profiles of the wheel of the test vehicle and analyzed the wheel/rail contact geometry with a mileage of the test vehicle. In experiment with test vehicle, we have got the useful data to design the steering controller of the wheelset.

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A Study on the Functional Sleeve Pattern of Sports Climbing Wear (스포츠 클라이밍 웨어의 기능성 소매패턴 연구)

  • Im, Ga Bin;Park, Ju Hee
    • Journal of the Korean Society of Clothing and Textiles
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    • v.41 no.4
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    • pp.585-598
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    • 2017
  • Sports climbing requires more maximum body motion range than any other sport. This study examined what element affects the actions of sports climbers and suggest an ideal pattern archetype to maximize function based on motion. The theoretical background included abstracted elements influencing clothing design by researching the body type of sports climbers and the motion of sports climbing. Along with the characteristic of climbing wear, this study also conducted a comparative analysis of sleeve patterns for sports climbing wear and general sports jackets, abstracting comparative parts that influence sports climbing wear design. To develop the final research archetype, research was done on 107 sports climbers in their 20s-30s that selected the top 3 brands and collected patterns as well. A research archetype was selected based on 3-D virtual clothing and developed into 4 different patterns with different sleeve cap heights. Appearance evaluation and a motion functionality evaluation were then conducted in order to select a final research archetype adequate for sports climbing based on evaluation findings. In addition, this study identified aesthetical problems of the final research archetype produced based on functionality that could suggest an archetype for a climbing jacket that could be visually satisfying through appearance evaluations and motion functionality evaluations.