• 한국정밀공학회지
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• 제24권7호
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• pp.98-105
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• 2007

In modern industries, materials are required that possess multi-functional properties and at the same time flexibility in their shapes with structural stability. The major technology realizing this requirement consists of thinning metal wires and laying them with stable contact nodes. This research has dealt with a new method to manufacture thin wires by drawing without applying dies, but with introducing enforced necking, which enables to process multi-ends. Based on the new method, the process dynamics was modelled and its steady-state characteristics were analyzed. Results showed that the profiles of the material velocity in the drawing zone increased with a downward convex shape, while the cross-sectional area decreased with the shape of upward convex. The microwave heating turned out to be effective in wire drawing, but dependent on the input feeding direction. The variation in the diameters of the drawn wires was negatively affected by increasing the drawing ratio.

• 대한기계학회논문집A
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• 제25권2호
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• pp.330-337
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• 2001

Wire drawing process of the high carbon steel with a high speed is usually conducted at room temperature using a number of passes or reductions through consequently located dies. In multi-stage drawing process, temperature rise in each pass affects the mechanical properties of final product such as bend, twist and tensile strength. Also, this temperature rise during the deformation is the reason that the wire in drawing process is broken by the embrittlement due to rapid strain aging effect. This paper presents the estimation of the wire temperature for the multi-stage wire drawing process. Using the proposed calculation method of wire temperature, temperature rise at deformation zone as well as temperature drop in block considering the heat transfer between the block and wire were calculated. As these calculated wire temperatures were applied to the real industrial fields, it was known that the calculated results were in a good agreement with the measured wire temperature.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1986년도 학술발표초록집
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• pp.48-48
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• 1986

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1996년도 춘계학술발표회 논문집
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• pp.114-117
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• 1996

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2000년도 봄 한국섬유공학회 학술발표회 논문집(Proceedings of the Korean Textile Conference)
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• pp.93-96
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• 2000

• 전기화학회지
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• 제6권2호
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• pp.134-140
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• 2003

기능성 도판트인 dodecylbenzensulfonic acid(DBSA)와 혼합도판트{(DBSA와 $LiClO_4$, NSA(2-naphthalenesulfonic acid), DEHSA[di(2-ethylhexyl)sulfosuccinic acid]}를 사용하여 전기화학적방법에 의한 연신성 폴리피롤(Ppy-DBSA, Ppy-mixed dopants)필름을 제조하였다. 전기화학적 방법에 의해 제조된 폴리피를 괼름은 zone drawing방법을 사용하여 1.0-2.5배 연신시킬 수 있었으며, 연신된 폴리피롤 필름의 전기전도도를 측정하였다. 연신율이 증가함에 따라 필름의 전기전도도가 증가함을 볼 수 있었다. 이 현상은 연신율에 따른 결정성 증가로 설명 할 수 있었다. 1.0-2.5배 연신된 폴리피를 필름(Ppy-DBSA, Ppy-mixed dopants)을 온도변화에 따른 전하 이동 경로는 모두 power raw에 적합함을 볼 수 있었다.

• 소성∙가공
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• 제9권1호
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• pp.3-9
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• 2000

The new FLD of the laser welded blank, which includes FLCs of welded zone and base metals, is introduced. For the forming limits of welded zone, the hemispherical dome punch tests were performed with various widths of asymmetric specimen. The FLC0 as well as the dome height at fracture associated with various specimen widths in the same and different thickness combinations were found to see the formability depending on thickness combinations. In order to show the application of the new FLD, the measured strains of squared cup drawing and simulated strains of door inner panel stamping were compared with those of FLCs. The successful prediction of fracture in the applications reveals that the forming limits of welded zone and base metals should be separately found for more accurate evaluation of the formability and workability of the laser welded blank.

• 한국정밀공학회지
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• 제18권5호
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• pp.57-64
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• 2001

The high speed in the wire-drawing process to meet the demands for the increased productivity has a great effect on the heat generated due to plastic deformation and friction between the wire and the drawing dies. During the high carbon steel wire drawing process, the temperature rise gives a great influence to the fracture of wire. In this paper, to control the temperature rise in the wire after the deformation through the drawing die, the calculation method of the wire temperature, which includes the temperature rise in the deformation zone as well as the temperature drop in the block considering the heat transfer among the wire, cooling water and surrounding air, is proposed. These calculated results of the wire temperature at the inlet and exit of the drawing die at each pass are compared with the measured wire temperatures and verified its efficiency. So, using the program to predict the wire temperature, the isothermal pass schedule program was developed. By applying this isothermal pass schedule program to the conventional process condition, a new isothermal pass schedule is redesigned through all passes. As a result, the possibility of wire fracture could be considerably reduced and the productivity of final product could be more increased than before.

• 폴리머
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• 제27권4호
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• pp.323-329
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• 2003

기능성 도핑제인 di(2-ethylhexyl) sulffsuccinate sodium salt (NaDEHS)을 사용하여 화학적, 전기화학적 방법에 의한 연신성 폴리피롤을 합성하였다. 화학적, 전기화학적 방법에 의해 제조된 폴리피를 필름은 구역 연신 방법을 사용하여 1.0∼2.5배 연신시킬 수 있었으며, 연신된 폴리피를 필름의 전기 전도도를 측정하였다. 연신율이 증가함에 따라 필름의 전기 전도도는 증가함을 볼 수 있었다. 이러한 현상은 연신율에 따른 결정성 증가로 설명할 수 있었다. 온도변화에 따른 전하 이동 경로는 1.0-2.0배 연신된 폴리피롤의 경우 3차원 variable range hopping모델, 2.5배 연신된 폴리피롤의 경우 1차원 VHR모델에 적합함을 볼 수 있었다.

• KIEAE Journal
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• 제7권4호
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• pp.75-80
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• 2007

The purpose of this study is to analyze architectural plans of lower part of super tall mixed-use residential building for understanding its functions for urban. The area of this research are limited to super tall mixed-use residential building which were built in Seoul, Kyoung-gi area, and new towns. For this purpose, theories for super tall mixed-use residential building and non-housing parts were researched, and characteristics of selected cases for field research were analyzed by studying drawing materials. The research focused on scale, type of building, included programs for public spaces, and characteristics of location. As a result, every cases were designed as 'outdoor transition zone-centered type', and for urban function, non-housing facilities were condensed to increase convenience. In addition, ratio of non-housing part were incresesed with public spaces design for residents, and various programs were inserted.