• 열처리공학회지
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• 제12권2호
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• pp.136-144
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• 1999

The study on the wear characteristics of compound layers formed during gaseous nitrocarburising in the medium carbon boron steels and the plain carbon steel has been carried out by using a pin-on-disc type wear test machine under the oil lubricating condition at room temperature and by varying applied loads, sliding speeds and wear distances. Values of friction coefficient measured at the sliding speed of 0.4m/sec under the oil lubricating condition have been shown to decrease considerably with increasing applied load and become gradually a constant value as load is increased to a higher value, showing that the transition load for friction coefficient appears at an applied load of 247.2N. The length and volume wear rates of compound layer have been revealed to relatively constantly increase, also showing that the wear life per unit thickness of compound layer turns out to be superior as porous layer has a denser and thinner appearance. As the sliding speed increases during wear test performed by varying sliding speed at a load of 63.2N under the oil lubricating condition for medium carbon boron steel nitrocarburised in gas atmosphere, the wear rate has been found to increase, the friction coefficient to decrease and the wear life per unit thickness of compound layer to decrease considerably.

• 복식문화연구
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• 제7권6호
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• pp.98-115
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• 1999

As sports infiltrates each field of modern society and becomes familiar, sports wear was changed functionally and was introduced and enveloped into everyday dress. Modern sports wear has been the settled in everyday life deeply and become the clothes of life which are worn regardless of place, time and age. The aim of this paper was to clarify what kind of fashion of sports style would be given to the modern people. In this study, sports wear which has become everyday dress classified from a gender point of view. It was divided into masculine image, feminine image, and neutral image. Sports wear of masculine image generated a silhouette which emphasized the shoulder with the aspiration for youth and health. Wide shoulder was considered as the symbol of masculine beauty and the expression of healthy beauty. It was reflected well in body conscious look. And owing to the development of up-to-data materials, innovation of design, and the study of human body technology, the functional character was settled in the sports wear which showed masculine image. Sports wear of feminine image was represented fashion of body exposure, body feet with body conscious look, and romantic mode. This image was expressed fashion as comforts, pleasant, active design, materials, color, and romantic feminine beauty. Sports wear of neutral image was expressed into unisex clothes. This cloths have no difference in gender, age, and class. It was used as casual sports wear. In the 1960s, young generation participated in such street sports as street basketball and skate. They usually sore the sports wears of neutral image such as cycling, skating, and ski. In the materials of sports, the development of up-to-data material like lycra made the sayings lifelike, “up-to-data material is the second skin” It show that glamorous feminine image and strong masculine image coexisted. The contemporary concept of sportswear is no longer limited to those clothes for sports found in such places like tennis court or swimming pool. Now, the sports wear become more like casual activity wear all classes of people can enjoy in their life regardless of where they are, when they wear, and even how old they are.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.167-172
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• 2011

Generally, the analysis of railroad wear data is most effective method for the efficient railway maintenance. The wear of railway track affects loss of rough ride, noise or vibration of train and traveling safety. Moreover as the track is worn away, this promotes destruction of structural mechanism of rail track which can bring about increasing of rail track maintenance cost drastically. For this reason, it is very important and interested research subject to design railway track structure and to analyse train movement mechanism based on systematic analysis of the reasons causing rail wear possible in real field. In this research, for the efficient maintenance, Life Cycle Performance of rail track and maintenance characteristics are computed considering some track components such as track type, contracting type, sleeper type and roadbed type. Time - Wear probabilistic distribution relationship as well as multiple regression analysis based on time, curvature and wear data are computed to predict the service life remainder of railway track and to be adapted to safety assessment.

• 대한기계학회논문집A
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• 제33권10호
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• pp.1091-1098
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• 2009

In this paper, the procedure to estimate fatigue crack initiation life has been established by considering fretting wear and multiaxial stress states on the contact surface of press-fitted shafts. And a method to calculate the local friction coefficient during the running-in period of fretting wear process has been proposed. The predicted result of worn surface profile in the press-fitted shaft with non-linear local friction coefficient can avoid excessive wear depth estimation compared with that for the case of constant local friction coefficient. Furthermore, the predicted fatigue crack initiation lives based on Smith-Watson-Topper model considering the fretting wear are in good agreement with the experimental data. Consequently, the present method is valid not only for predicting worn surface profile, but also for assessing fatigue crack initiation lives considering the fretting wear during the running-in period in press fits.

• 소성∙가공
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• 제12권1호
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• pp.18-25
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• 2003

This paper explains the process design for improving tool life in the conventional hot forging process. The thermal load and the thermal softening are happened by contact between the hotter billet and the cooler tools in hot forging process. Tool life decreases considerably due to the softening of the surface layer of a tool was caused by a high thermal load and long contact time between the tools and the billet. Also, tool life is to a large extent limited by wear, heat crack and plastic deformation in hot forging process. Above all, the main factors which affect die accuracy and tool life we wear and the plastic deformation of a tool. The newly developed techniques for predicting tool life are applied to estimate the production quantity for a spindle component and these techniques can be applied to improve the tool life in hot forging process.

• 한국의상디자인학회지
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• 제20권3호
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• pp.1-14
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• 2018

This study examines female consumers' purchasing behavior of outdoor wear based on their leisure activities and life style using the questionnaire method. SPSSWIN was used for data analysis. The results are as follows: first, there is a significant difference in demographic characteristics of outdoor wear consumers depending on life style types. Second, outdoor wear purchasing behavior by lifestyle types showed no significant correlation between lifestyle types and the extent of interest in outdoor wear. Consumers valuing private leisure time are more engaged in searching for commercial information compared to other groups and a significant difference was seen in the standard for selecting products, functional materials, colors, and comfort depending on life style type. Third, there is no significant difference in demographic characteristics of outdoor wear consumers based on the extent of leisure activity. Fourth, there was significant correlation between the extent of leisure activity and interest in outdoor clothes. Therefore, this study shows that the life style of female consumers and the extent of leisure activity are significantly related to purchasing behavior. Hence this study can be effectively used by the outdoor wear industry to analyze characteristics of female consumers and plan and establish a suitable marketing strategy.

• 한국자동차공학회논문집
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• 제7권5호
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• pp.213-220
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• 1999

The life data analysis of the system and component are useful to describe the result of reliability test in product life to satisfy customer's growing need and to change test specifications or design criteria by life data analysis. And vehicle durability tesr occurred market environment. In this study, a statistical analysis for the wear life of brake pad linings helped perform correlation procedure between vehicle durability test and market. B-life values of the brake pad wear life data from both vehicle durability test and marker usage were compared to determine acceleration of the test by the Weibull, normal and log-normal distribution. The acceleration coefficient of the vehicle durability test can access to evaluate design criteria of product and test specification.

• 복식문화연구
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• 제28권6호
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• pp.771-786
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• 2020

This study aims to develop a life-friendly, wrap-one-piece style dance sports practice wear considering the physical characteristics of middle-aged, abdominally obese women. These types of practice wear allow people to enjoy exercise easily and to wear these garments as daily wear while meeting the requirements for dance sports wear. The three participants selected for this study were all women with five or more years of dance sports experience and were all average sized on Korea's abdominal obesity scale. In the first phase of the study, practice wear was created in a total of nine styles with three different styles of neckline depths for three different styles of dress skirt lengths. In the second phase of the study, the practice wear was created in 15 styles with five different styles of sleeve lengths for three different styles of waistline heights. After analyzing the design preferences of the participants, the fit preferences of the designs were evaluated and the final appearance was analyzed in order to suggest a pattern. The results of the subjects' first and second preference evaluations showed a preference for a 10 centimeter neckline depth, for high waistlines, and for elbow to wrist-length sleeves. The implementation of this research is expected to be extensive, as its results can be used as basic data for making lifestyle dance sports practice wear that covers the physical insecurities of middle-aged, abdominally obese women and enables them to enjoy their leisure time.

• 열처리공학회지
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• 제7권3호
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• pp.199-205
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• 1994

The fracture characteristics and tool life of ceramics and WC, CBN cutting tool when turning heat treated steel STD11($H_RC$ 60) were investigated experimentally to clarify the machinability and optimum tool materials in cutting of difficult-to-cut material with high hardness. Forthermore, the behaviors of the tool wear and failure were examined with regard to cutting force. The hardened steel wore the cutting tool edge rapidily and increased the cutting forces, especially radial force. The tool was worn by the abrasive action. Flank Weat of $Al_2O_3-TiC$ ceramic and WC tool become relatively large and CBN & $Al_2O_3$, ceramic tool had a long life among the tool materials tested. The tool fracture patterns were just like minor cutting wear, flank wear, crater wear, notch wear, chipping. Flank wear rate was accelerated by occurrence of chipping. During the proceeding of machining, it was possible to foresee the catastrophic fracture of tool by abrupt increase of radial force.

• 한국기계연구소 소보
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• 통권19호
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• pp.69-79
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• 1989

Cutting tool life monitoring is a critical element needed for designing unmanned machining systems. This paper describes a tool wear measurement system using computer vision which repeatedly measures flank and crater wear of a single point cutting tool. This direct tool wear measurement method is based on an interactive procedure utilizing a image processor and multi-vision sensors. A measurement software calcultes 7 parameters to characterize flank and crater wear. Performance test revealed that the computer vision technique provides precise, absolute tool-wear quantification and reduces human maesurement errors.