• 대한기계학회논문집
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• 제15권1호
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• pp.145-153
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• 1991

본 연구에서는 Toh가 개발하여 stretchforming에 응용한 강소성 대변형 이론 을 압연문제에 적용하여 강소성 대변형 유한요소 프로그램을 개발하는데 있다.

• 복식문화연구
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• 제10권3호
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• pp.213-235
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• 2002

The purpose of this study was to recognize the meanings of plastic language by analyzing the sign of the Graffiti depicted in western modern costumes. And the scope of this study was focused on analysing the costumes from 1980's when the Graffiti was recognized as one of the plastic arts. Graffiti was an unprofessional and covert desire of self-expression, having a close relation with our lives. It was used in diverse ways with repeating creation, development, and extinction, from expressing liveliness in Old Stone Age through describing symbolic meaning in the modern art. Graffiti means rude, humorous, or political writing and pictures on the walls of buildings. It's different from the delicate letters or pictures to inscript on the tree or rocks. Being introduced as part of Post-modernism in the 1970s, Graffiti was acknowledged as a new artistic action with the culture of hip-hop. In addition the Graffiti, the expression of sign was reflected artist's internal consciousness with boundless sign. The sign is something to transmit message from the nonverbal point of view, the oldest sign was the sign for petition or the expression of something as a primitive form. Sign can be defined as a framework of life inherited as a practice from the primitive age long past. Graffiti was cited as a concrete example of sign, theme of this paper, and general understanding on sign expression was pursued through free work which all artists present with essential and positive ways using signs, their own languages, and life style. The result of this study was summarized as follows: Since the end of the 20th century, a lot of fashion designers have represented symbolic images, such as letter and signs, as purely personal ways of expression through the western costumes. It was found that fashion designers of the Graffiti whose free work style from inherent inner consciousness might provide a basic framework to search for complex signs of modem costumes naturally understood life itself as plastic art, and sublimated human inherent desire and their inner world through their works.

• 한국패션뷰티학회지
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• 제5권4호
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• pp.149-157
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• 2007

Hair style was mean of visual symbol that display position or wealth about human life. Also, have spoken for cultural value as human body plastic art that speak for the age. I wished to study about modeling of hair style and interrelationship of color by analyzing systematically laying stress on color through contest creation work consisted in beauty art congress. Urpose of this study is as following. First, examines domestic' outside great council work head change by era, and studies Hair Work's change in work head. Second, Hair Color's change that appear in domestic' outside contest work head studies effect that get in work. Method of study runs parallel literature study and supporting research, utilized domestic' outside literature, connection paper, magazine, picture data etc. To literature study, and work picture data examined laying stress on work that is choosesed picture dataworld beauty use association (OMC) data etc. that appear in domestic' outside beauty art magazine to examine closely specification and stability of beauty art game style and participates in domestic and world beauty art contest. In this study, domestic' characteristic, and effect that collar gets in work head of collar that collects outside contest participating in an athletic contest hair style by ($1981{\sim}$until present) by year and appears in contest work head and in work since analyzing study forward $2007{\sim}2008$ year direction of collar. First, stream of whole color of the 1980s Brown gave highlight color point partially to basis, and was consisted of creative style and do Gold base color on the whole in Hair by Night item. Second, various Hair color was popularized in the 199Os, and Tuton's color appeared in beauty art game work, and I contributed to improve technique that step-up gradation color appears and does technique to highlight in neon orange in creative style and Hair by Night item by entrance on the stage of neuter gender color.

• 소성∙가공
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• 제8권1호
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• pp.101-107
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• 1999

The upset forging stage is the initial work in the forging process. It is used to remove the segregation and cavities of the ingot. Specially in handling large sized ingot, an improper upset forging can cause serious surface tearing. However, there is no detail reference for stable upset forging work. To resolve this difficulty, we studied several factors such as upset forging time, temperature varation of ingot, damage, load and stain rate etc., by using the rigid-plastic finite element approach available in the DEFORM code. Numerical simulation results indicated that: the load value of upset forging works shows severe decreasing trend at a certain point, same as strain rate. Also defects were found to be concentrated around the upper and lower portions of the ingot. With these results, we can estimate a guideline for stable upset forging work.

• 비파괴검사학회지
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• 제23권6호
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• pp.616-621
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• 2003

There are various Non-Destructive Evaluation (NDE) techniques used for measurement of residual stresses in material, such as magnetic methods, X-ray diffraction, Ultrasonic velocity measurement etc. The capabilities, applications and limitations of these techniques for evaluation of cold work/plastic deformation were studied and compared. Mild steel plates were subjected to different degree of cold deformation and were analyzed by Magneto-mechanical Acoustic Emission (MAE), Barkhausen Noise (BN) and magnetic properties (hysteresis loop parameters analysis). Further, these specimens were analyzed by X-ray diffraction and ultrasonic velocity measurements. The microhardness measurement and microstructure studies of these cold worked plates were also carried out. The results of all these studies and comparison of different techniques are discussed in this paper.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.841-843
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• 2006

In high-performance cold work applications, tool failure depends on the predominating loading conditions. Typical failure mechanisms are a combination of abrasive wear, adhesive wear, plastic deformation, cracking and edge crumbling. In this paper we demonstrate how the microstructure of tool steels can be positively influenced by modifying the alloying system and the production route to meet the demands of the different loading situations which occur during operation. The investigation was focused on ductility, fatigue strength and wear resistance. Theoretical considerations were confirmed by practical tests.

• Transactions on Electrical and Electronic Materials
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• 제2권3호
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• pp.28-32
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• 2001

It was studied in the present work how the thermal cycling performance of LOC (lead on chip) packages depends on the package construct or leadframe materials. First, package body thickness and Au wire diameter were manipulated for the selection of proper package design. Secondly, two different types of leadframe materials (i.e. copper and 52%Fe-48%Ni alloy) were tested to determine the better material for improved reliability margin of plastically encapsulated microelectronic packages. This work shows that manipulating package body thickness was more effective than an increase of Au wire from 23$\mu\textrm{m}$ to 33$\mu\textrm{m}$ for the prevention of wire debonding failure. Further, this work indicates that the LOC packages including the copper leadframes can be more susceptible to thermal cycling reliability degradation due to chip cracking than those including the alloy leadframes.

• Nuclear Engineering and Technology
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• 제53권6호
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• pp.1909-1923
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• 2021

We experimentally investigated the effects of thermal aging and cold work on the microstructure, mechanical properties, and primary water stress corrosion cracking (PWSCC) initiation time for Alloy 182 welds. The effects of thermal aging and cold work on the PWSCC initiation time of Alloy 182 were modeled based on the plastic energy concept and the PWSCC initiation data of this study and previous reports by considering censored data. Based on the results, it is estimated that the PWSCC resistance of the Alloy 182 weld firstly increases and then decreases with thermal aging time when the applied stress is kept constant.

• 유기물자원화
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• 제14권2호
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• pp.101-111
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• 2006

본 연구에서는 폐플라스틱의 재활용방법 (물질재활용, Refused Derived Fuel(RDF), 고로원료화 및 유화)에 대한 환경 영향을 분석하기 위하여 전과정평가(LCA)가 수행되었다. 이 연구에서는 6가지 환경영향 범주를 사용하였다. 폐플라스틱의 재활용방법 중 가장 큰 영향을 미치는 범주는 지구온난화로 나타났으며, 나머지들의 영향은 미비한 것으로 나타났다. 지구온난화의 영향을 살펴보면 물질재활용, RDF화 및 고로원료화에 대해서는 환경성이 음(-)의 값으로 나타났으며, 이러한 현상은 신재 플라스틱의 대체재로 사용함으로써 환경부하 삭감효과가 크기 때문인 것으로 밝혀졌다. 그러나, 유화는 양(+)의 값으로 나타나 환경부하가 증가하는 것으로 나타났으며, 이것은 사용량이 많은 전력의 생산과정에서 발생하는 $CO_2$가 주원인으로 밝혀졌다. 오존층파괴에 대한 영향은 유화방법이 환경부하가 크게 나타났으며, 이러한 현상은 유화 공정자체에서 발생되는 오존층파괴 물질에 의한 영향으로 판단되었다. 본 연구 결과들은 폐플라스틱 재활용을 향상시키는데 유용한 자료로 활용될 수 있음을 보여주었다.

• 한국재료학회지
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• 제24권4호
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• pp.201-206
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• 2014

TiC-21 mol% Mo solid solution (${\delta}$-phase) and TiC-99 mol% Mo solid solution (${\beta}$-phase), and TiC-(80~90) mol% Mo hypo-eutectic composite were deformed by compression in a temperature range from room to 2300 K and in a strain rate range from $4.9{\times}10^{-5}$ to $6.9{\times}10^{-3}/s$. The deformation behaviors of the composites were analyzed from the strengths of the ${\delta}$- and ${\beta}$-phases. It was found that the high strength of the eutectic composite is due primarily to solution hardening of TiC by Mo, and that the ${\delta}$-phase undergoes an appreciable plastic deformation at and above 1420 K even at 0.2% plastic strain of the composite. The yield strength of the three kinds of phase up to 1420 K is quantitatively explained by the rule of mixture, where internal stresses introduced by plastic deformation are taken into account. Above 1420 K, however, the calculated yield strength was considerably larger than the measured strength. The yield stress of ${\beta}$-phase was much larger than that of pure TiC. A good linear relationship was held between the yield stress and the plastic strain rate in a double-logarithmic plot. The deformation behavior in ${\delta}$-phase was different among the three temperature ranges tested, i.e., low, intermediate and high. At an intermediate temperature, no yield drop occurred, and from the beginning the work hardening level was high. At the tested temperature, a good linear relationship was held in the double logarithmic plot of the yield stress against the plastic strain rate. The strain rate dependence of the yield stress was very weak up to 1273 K in the hypo-eutectic composite, but it became stronger as the temperature rose.