• 동력기계공학회지
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• 제5권3호
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• pp.73-79
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• 2001

The purpose of this investigation is experimentally to clarify the machinability and tool wear of STS 304 steel pipe material for piping. In order to determine the effects of cutting parameters and tool wear on thrust, torque, AE RMS, drilling is conducted on CNC milling machine. In this experiment, it is measured that thrust, torque, tool wear length, tool wear area and AE RMS during drilling using Hss tool. It has been found that a) During the drilling, the thrust and the torque of the STS 304 pipe are received more the effect of the feed than the spindle speed and the thrust increase with the increase of feed, b) The value of the AE RMS is been larger the effect of the cutting speed than the feed rate, and the value of the AE RMS increase with the increase of spindle speed, c) It has been found that the suitable feed in feed condition of 0.03, 0.05, 0.1, 0.15mm/rev is below 0.05mm/rev, d) The value of the AE RMS was shown a characteristic of the jump value during it was a sudden inrcrease of the tool wear. The increased character of the AE RMS value can be known an effective factor of the tool wear detection, and e) It can be quantitatively evaluated the condition of the tool according to calculate a area of the drill wear image which is obtained by a vision system.

• 한국의상디자인학회지
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• 제16권1호
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• pp.91-103
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• 2014

In this study, 70 national brands among men's wear brands were selected to examine linguistic characteristics of domestic national men's wear brand names. Linguistic factors which were used in national men's wear brand names were analyzed to understand their characteristics. Formative and semantic characteristics of each brand name were analyzed on the basis of the results from previous studies. It was found that long words with over four syllables are preferred than short words and single words in the form of noun are frequently used for domestic national men's wear brand names in terms of linguistic formality. English is most widely used in brand names, and European languages such as French, Spanish, and Italian are also used frequently under the influence of the country of origin. Next, the analysis result on the semantic characteristics of domestic national men's wear brand names showed that descriptive brand names are used to convey brand information directly and easily, or freestanding brand names which are absolutely irrelevant and newly coined words are chosen to create a characteristic image. In other words, brand names represent detailed business and product category of men's wear by forming a brand image of men's wear (ex. Man, Homme, Zio), and provide the information about properties and benefits related to the product such as dignity, masterpiece, and luxurious lifestyle to consumers by presenting the concept of the brand.

• 한국기계가공학회지
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• 제16권4호
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• pp.9-15
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• 2017

In hot forming process, the dies in which excessive worn or crack occurs is reused after repair. Generally hot forming dies are recycled through a welding repair method. Welding repair methods are highly dependent on the skills of engineer. It causes process defects such as dimensional defects and structural defects. Recently, the metal 3D printing method has been applied to the repair of used dies. The aim of this study is to evaluate the wear characteristics of AISI H13 tool steel repaired by 3D printing method. Three kinds of wear specimens were fabricated by using 3D printing, welding, and initial material. A pin-on-disk wear test was carried out to evaluate the wear characteristics. From the result of wear test, the wear characteristics of 3D printing method was superior to that of the welded material, and was similar to that of the initial material.

• 복식
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• 제61권1호
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• pp.69-83
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• 2011

This study applied cartoon-like simple and implicit symbol of Keith Haring works to tubular jacquard knit, designed woman casual knit wear with fun, explicit and activities using fluorescent yarns with explicit features. This study aimed to propose the directions for new market pioneering that meets the emotional requirements of modern people by raising the level of utilization and expression area of knit fashion, and to present the constructive directions for high value-added knit wear by designing highly effective knit wear. Methods of this study examined the lifetime and artistic background of Keith Haring and collected his works through searching of internet, scholastic publications or thesis. Formative types and colors of works collected were analyzed and classified according to characteristic standards of Haring and characteristic formativeness and color of works were extracted. The result of this study is as shown below: First, the feature of his works can be summarized into motif that has symbolic and implicit cartoon-like lines including narratives as well as enormous number of works. Such feature is very suitable for variation and recombination in realization of design and has unlimited potentials for development. Second, image colors can be extracted such as black and white, original color and fluorescent paints, which reflects the intention of artist who put focus on communication with the public. Such color feature is very suitable for design motif that has explicitness of reflecting the intention of artist through use of special fluorescent yarn. Third, I made it as reversible wear that has effects of increasing or decreasing the explicitness according to color area ratio using the feature of textures allowing use of both sides as well as form stability of tubular jacquard. Fourth, by adjusting the thickness of fabric with controlling of ply in fabric using poly yarn and wool union yarn, I could obtain good results of study in terms of technique that can express various materials with embossed dynamic effects of unevenness on flat surface.

• 정보저장시스템학회논문집
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• 제3권3호
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• pp.139-143
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• 2007

In recent years new recording media and materials for head-disk interface (HDI) have been developed in order to increase the recording density of storage devices and decrease the cost of production. It is well known that HDI in hard disk drive (HDD) needs high durability and stability. The tribological characteristic of commercialized HDI systems is an important indicator of the HDD reliability. In this study, experimental investigation on the wear coefficient of commercialized hard disk slider pads was performed. The slider was placed on top of a hard disk and allowed to slide for a set distance. The wear of the pads was measured after the sliding tests. The result showed that the micro-bumps in commercialized HDD have extremely low wear coefficient of $10^{-11}$. The results of this work may be used for further development of the HDI technology for HDD.

• 한국기계가공학회지
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• 제9권2호
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• pp.40-46
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• 2010

The purpose of this study is to show the friction and wear characteristics on the vapor deposited coating layers on the SCM415 steel. In this research, frictional wear characteristic of coating materials such as TiAlN+WC/C Multilayer Coating was investigated under room temperature, normal air pressure and nothing lubricating condition. Therefore this study carried out research on the friction coefficient, micro hardness(Hv), roughness, EPMA on the vapor deposited coating layers on the SCM415 steel. As the wear experimental result, the coefficient of friction decreased according to experimental load increases.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1997년도 제25회 춘계학술대회
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• pp.25-32
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• 1997

The neural network was applied to identify wear debris generated from the lubricated machine moving surface. The wear test was carried out under different experimental conditions. In order to describe characteristics of debris of various shapes and sizes. The four parameter(50% volumetric diameter, aspect, roundness and reflec- tivity) of wear debris are used as inputs to the network and learned the friction condition of five values (material 3, applied load 1, sliding distance 1). It is shown that identification results depend on the ranges of these shape parameter learned. The three kinds of the wear debris had a different pattern characteristic and recognized the friction condition and materials very well by neural network.

• 한국표면공학회지
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• 제47권6호
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• pp.282-286
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• 2014

Wear characteristic of the nitrided SKD61 which is a typical mold material using for the extrusion of Al6061 alloy was investigated. The surface of SKD61 was nitrided by salt bath and plasma processes. The thickness of surface nitride layer was about $8.9{\mu}m{\sim}21.3{\mu}m$. Reciprocating friction wear test conducted using pin on disk type indicated the plasma treatment followed salt bath has a lower friction coefficient and a smaller adhesive wear with Al6061 alloy. That was identified by the $Fe_4N$ which has a better wear resistance than FeN mainly formed by plasma nitriding.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 추계학술대회논문집
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• pp.89-90
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• 2008

This paper studies the effect of pad at initial stage and wear during braking on the dynamic contact pressure distribution. Wear is influenced by variable factor (contact pressure, sliding speed, radius, temperature) during dynamic braking and variation in contact pressure distribution. Many researchers have conducted complex eigenvalue analysis considering wear characteristic with Lim and Ashby wear map. The conventional analysis method is assumed the pad has smooth and flat surfaces. The purpose of this paper is to validate that wear rate induced by braking is considered for the precise squeal prediction. After obtaining pad wear from experiment, it is incorporated with FE model of brake system. Finally, the comparisons in fugitive nature of squeal will be carried out between the complex eigenvalue analysis and noise dynamometer experiment.

• Tribology and Lubricants
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• 제22권5호
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• pp.276-281
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• 2006

The fractal dimension is quantitatively to define the irregular characteristic of the shape in natural. It can be useful in describing morphological characteristics of various wear particles. This paper was undertaken to diagnose failure condition for sliding members in lubrication by fractal dimension. It will be possible to diagnose wear mechanism, friction and damage state of machines through analysis of shape characteristics for wear particle on driving condition by fractal parameters. In this study, the calculating and analyzing methods of fractal dimensions were constructed for the condition monitoring and wear particle analysis in lubricant condition. So, we carried out the Friction and wear test with the ball on disk type tester, and the fractal parameters of wear particle in lubricated conditions were calculated. Fractal parameters were defined as texture fractal dimension ($D_{t}$), structure fractal dimension ($D_{s}$) and total fractal dimension (D).