• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.3
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• pp.688-696
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• 1995

Cemented carbides, best known for their superior mechanical properties such as high strength, high hardness and high wear resistance, have a wide range of industrial applications including metal working tools, mining tools, and wear resistance components. The cobalt has been used as a binder in the WC-based hard composites due to its outstanding wetting and adhesion characteristics even though its expensiveness. Therefore many studies attempted to find a better substitute for cobalt as binder to decrease production costs. This investigation is a pre-step to study dynamic fracture characteristic evaluation of a WC-Co hardmetal were evaluated by using the instrumented Charpy impact testing procedures. It was found that the dynamic characteristics of used strain amplifier were very important experimental factors to extract valid dynamic fracturing data in WC-Co specimens. It was suggested by showing some experimental examples that when we wished to evaluate dynamic fracture toughness for cemented carbide composites by using the instrumented Charpy impact testing procedure, a careful attention must be given to obtain valid results.

• International Journal of Costume and Fashion
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• v.6 no.2
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• pp.43-54
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• 2006

In the history of fashion, the category of knitted items was traditionally associated with ordinary clothing products like undergarments and socks. However, in a mere century Chanel has changed that idea by bringing into fashion consciousness items such as sports sweaters, jerseys, and suits, and so it has been necessary to upgrade this notion. As the needs of the times and new inventions have an inseparable relationship, knit fashion was also born with a close relationship with the zeitgeist of the time - the feminine movement, the rise of sports fashion and the world war - adapting itself up to the present time through continuous changes. Most brands are elevating knit from a mere decoration into a collection piece in a large number of collections every year. The number of brands that cannot exist without knit is increasing, such as Sonia Rykiel, Missoni, and so on. This essay is written with the purpose to study the birth, growth and future potential of knit items. The first stage concentrates on the age of knit's appearance (1910s-1930s). Contingent upon the collection of further data, this essay will be continued through the second stage (the 1960s - 1970s) and the third stage (after the 1980s).

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.80-84
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• 1996

This paper aims at reviewing the Possibility application over normal or abnormal, detection used by AE and the wear characteristics of grinding process. In this study, when diamond bur in dentistry with chosen grinding conditions were tuned at grinding. The variation of grinding resistance and hE signal is detected by the use of AE measuring system. The tests are carried out in accordance with diamond burs and workpiece; arcyl and bovine. According to the experiment results, the following can be expected; AE has the possibility to detect the state normality and abnormality. However, the grinding resistance measuring can find it difficult to detect it. It can be accurately excerpted from AE occurrence pattern in contact start point of diamond bur and bovine, grinding condition and derailment point. It is known that AE$\_$rms/ is well compatible with grinding resistance. According to the increase of the material removal rate, the specific energy of the diamond bur is inclined to decrease and the grinding resistance has a tendency to increase.

• The Research Journal of the Costume Culture
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• v.18 no.2
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• pp.304-321
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• 2010

The purpose of this study was to investigate the sensation seeking tendency and knitwear purchase behaviors of high school girls. The data were obtained from 475 high school girls at 6 high schools located in Daejeon. The method of study is a survey consisted of sensation seeking tendency items, knitwear purchase behavior items and demographic attribution. Data were analyzed by frequency, variance, crosstabs, and correlation analysis using SPSS WIN 17.0 program. The results of study are as follows. First, high school girls generally liked knitwears by reason of comfort and activity. Most girls purchased the knitwears to wear ordinary casual wear(81.5%). They usually thought sweater and cardigan to be representative of knitwears. Also, they mostly purchased the knitwears of simple and active design, achromatic color, 100% cotton, and solid or simple stripe pattern. The design and price were considered as important evaluation criteria in knitwear purchase. The information sources used by them were store display, friends, and internet. Second, the knitwear purchase behaviors of high school girls showed the difference between groups with high- and low-sensation seeking tendency. The most important factor of knitwear purchase was an unique and characteristic design in high group and a simple and active design in low group. In conclusion, high school girls liked knitwears and had different knitwear purchase behaviors according to the sensation seeking tendency.

• Journal of the Korean Society of Costume
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• v.60 no.10
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• pp.28-46
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• 2010

Variety and individuality are characteristic of consumer in modern society. For the necessity of new designed men's formal suit is on the rise with advance of party culture and change of wedding style. In addition to growing numbers of Korean grooms are getting more interested in make themselves well-groomed on the wedding ceremony. The purpose of this study is to develop the men's formal suit pattern for right fit and better style for Korean grooms. In order to find out how to modify their fit, comparison among the existing patterns was necessary. In this study we proposed new patterns of men's formal suit, a morning coat, a tail coat, tuxedoes, director's suit, three-peaces suit, navy blazer. Considering the results of this study, developed patterns were altered to fit better and to smarter. They were well graded in waistline position, shoulder shape, back princess line shape. Also they were best to move around sleeve and bodice. And the developed patterns were altered to make armhole narrower to make bodice length shorter, to make bodice slimmer. The researcher's pattern's were made up into garments using wool 100%, silk 100%. According to verify the improvements and grade better in both appearance and comport, it will be to take the lead men's formal dress culture and expand the base of popular consume for men's formal wear.

• Journal of the Korean Society of Costume
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• v.61 no.8
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• pp.100-113
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• 2011

The earlier notion of feminism regarding gender equality was changed into that of Postfeminism because of gender differences. The idea of Postfeminism has been present since the 1980s but has been influenced by modern culture theories such as Postmodernism, Poststructuralism, Theory of Power and Discourse and Psychoanalysis. Various features of Postfeminism are found in the medieval warrior images of contemporary fashion. Warrior costumes were men's exclusive property in the medieval ages, but as it is introduced as women's wear in the 21st century, it shows us new fashion images which are constructed by gender deconstruction, differences and pastiche. In this regard, the purpose of this study is to examine a key characteristic of Postfeminism fashion. An article described the historical costumes of medieval warriors and refocused on the development processes of feminism and then conducted an analysis on formative characteristics and Postfeminism tendencies in contemporary women's wear from 2000 to 2011. The results were that materials such as metallic and flexible materials, monotonic and red colors and detailed patterns of armor were used to display forms of exaggeration and restraint. These elements fully and correctly expressed the image of a medieval warrior woman in contemporary fashion. Postfeminism fashion is constructed with feminine power, gendered identity, sensual elegance and a postmodern body. Postfeminism is the contemporary cultural icon and is continuously influencing modern fashion design in the 21st century in a positive and powerful way.

• Composites Research
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• v.30 no.5
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• pp.310-315
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• 2017

In this study, we have investigated microstructure, mechanical properties and wear characteristic of aluminum metal matrix composites with a high volume fraction and uniformly dispersed SiC particles which produced by a liquid pressing process. The volume fraction of bimodal SiC/Al7075 composite was 12% higher than that of the monomodal SiC/Al7075 composite and a compressive strength is increased about 200 MPa. As a result of the abrasion test, the wear width and depth of the bimodal SiC/Al7075 composite were $285.1{\mu}m$ and $0.45{\mu}m$, respectively. The coefficient of friction of bimodal SiC/Al7075 was 0.16.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.23 no.6 s.165
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• pp.952-960
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• 1999

The effects of binder on the mechanical properties of the preforms and metal matrix composites (MMCs) were studied. Fibers were $9Al_2O_3{\cdot}2B_2O_3(Alborex)$, HTZ and $Al_2O_3$ fibers(Saffil) and binders were organic binder, inorganic binder, polyacrylamide under various PH conditions. Compressive strength of the preform increased with the addition of inorganic binder. The polyacrylamide did not improve the permeability of the preforms. PH of the slurry should be controlled because it affects the viscosity of the slurry. Good preforms were obtained under following conditions : 3 wt% inorganic binder, 0.1 wt% organic binder, 0.1 wt% polyacrylamide and PH 9. Tensile tests of MMCs were conducted at $20^{\circ}C,\;150^{\circ}C,\;250^{\circ}C,\;350^{\circ}C$ using MTS(100KN USA). Wear tests were conducted under various sliding speeds. High temperature($250^{\circ}C$) tensile strengths of Alborex/Saffil/AC8A and HTZ/AC8A are 80% and 75% of the room temperature tensile strengths respectively. The tensile and wear properties of the Alborex/Saffil/AC8A are superior to that of the HTZ/AC8A. The wear behavior of HTZ/AC8A shows more orthotropic characteristic than that of Alborex/Saffil/AC8A.

• Tribology and Lubricants
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• v.32 no.2
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• pp.44-49
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• 2016

Diamond mechanical polishing (DMP) is a crucial process in a sapphire wafering process to improve flatness and achieve the target thickness by using free abrasives. In a DMP process, material removal rate (MRR) is a key factor to reduce process time and cost. Controlling mechanical parameters, such as velocity and pressure, can increase the MRR in a DMP process. However, there are limitations of using high velocities and pressures for achieving a high MRR owing to their side effects. In this paper, we present the lapping characteristics and improvement of MRR by using a fixed abrasive plate through an experimental study. The change in MRR as a function of velocity and pressure follows Preston's equation. The surface roughness of a wafer decreases as the plate velocity and pressure increases. We observe a sharp decrease in MRR over the lapping time at a high velocity and pressure in the velocity and pressure test. An analysis of surface roughness (Rq and Rpk) indicates that wear of abrasives decreases the MRR sharply. In order to investigate the effect of abrasive wear on the MRR, we utilize a cutting fluid and a rough wafer. The cutting fluid delays the wear of abrasives resulting in improvement of MRR drop. The rough wafer maintains the MRR at a stable rate by self-dressing.

• Journal of the Korean Society for Heat Treatment
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• v.28 no.4
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• pp.181-189
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• 2015

Two types of advanced cold-work tool steels were characterized and compared. A higher-alloyed ledeburitic steel with primary carbides (denoted as 9Cr) and a lower-alloyed steel without primary carbides (5Cr) were fabricated by vacuum induction melting and subsequent hot forging. They were spheroidizing-annealed at $870^{\circ}C$, quenched at $1030^{\circ}C$ and tempered at 180 or $520^{\circ}C$. Their machinability after annealing and hardness, impact toughness, wear resistance after tempering were compared and interpreted in association with their characteristic microstructures. After annealing, 5Cr showed higher resistance to machining due to higher ductility and toughness in spite of lower strength and smaller carbide volume. Owing to smaller carbide volume fraction and the absence of coarse primary carbides, 5Cr showed even better impact toughness although the hardness was lower. The improved toughness of 5Cr resulted in excellent wear resistance, while smaller volume fraction of retained austenite also contributed to it.