• 한국기계가공학회지
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• 제15권1호
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• pp.26-33
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• 2016

In this study, a new method to develop a fixed diamond wire for silicon wafer machining by the multi-wire cutting method was developed. The new twist diamond wire has improved performance with high breaking strength and chip flutes structure. According to these characteristics, the new twist diamond wire can be used in the higher speed multi-wire cutting process with a long lifetime. Except the design of the new structure, the twist diamond wire is coating by electroless-electroplating process. It is good for reducing breakage and the falling-off of diamond grains. Based on the silicon material removal mechanism and performance of the wire-cutting machine, the optimal processing condition of the new twist diamond wire has been derived via mathematical analysis. At last, through the tensile testing and the machining experiments, the performance of the twist diamond wire has been obtained to achieve the development goals and exceed the single diamond wire.

• 항공우주산업기술동향
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• 제7권2호
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• pp.85-94
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• 2009

전투기에 처음 적용되었던 Fly-By-Wire (전자식 비행제어) 시스템은 여러 가지 장점으로 인해 까다로운 인증과정을 거쳐 민간 항공기에까지 적용되었고, 최근에는 소형제트기까지 적용 범위가 확장되고 있으며 미래에는 대부분 Fly-By-Wire 항공기가 주를 이룰 것으로 전망된다. 본 논문에서는 대형여객에서 소형제트기까지 민간 항공기에 적용되는 Fly-By-Wire 시스템의 구성 및 특성 등에 대하여 기술 하였다. 특히 비행조종컴퓨터 다중화 방안과 데이터 통신 버스, 조종면 작동기, Fly-By-Wire 시스템을 통하여 적용되는 제어 법칙 등에 대한 기술 개발 동향에 대해 고찰하였다.

• 소성∙가공
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• 제15권6호
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• pp.421-427
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• 2006

Drawing process of Al-1%Si bonding wire considering fine Si particle is analyzed in this study using FE-simulation. Al-1%Si boding wire requires electric conductivity because Al-1%Si bonding wire is used for interconnection in semiconductor device. About 1% of Si is added to Al wire for dispersion-strengthening. Distribution and shape of fine Si particle have strongly influence on the wire drawing process. In this study, therefore, the finite-element model based on the observation of wire by continuous casting is used to analyze the effect of various parameters, such as the reduction in area, the semi-die angle, the aspect ratio, the inter-particle spacing and orientation angle of the fine Si particle on wire drawing processes. The effect of each parameter on the wire drawing process is investigated from the aspect of ductility and defects of wire. From the results of the analysis, it is possible to obtain the important basic data which can be guaranteed in the fracture prevention of Al-1 %Si wire.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1995년도 추계학술발표회논문집(1)
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• pp.450-455
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• 1995

A three-dimensional numerical tool is developed to calculate the potential distribution, electric field, and conductance for any types of conductance probes immersed in the wavy liquid film with various shapes of its free surface. The tool is validated against various analytical solutions. It is applied to find out the characteristics of the wire-wire probe, the flush-wire probe and the flush-flush probe in terms of resolution, linearity, and sensitivity. The wire-wire probe shows high resolution and excellent linearity for various film thickness, but comparably low sensitivity for low film thickness fixed. The flush-wire probe shows good linearity and high sensitivity for varying film thickness, but resolution degrading with an increase in film thickness. In order to check the applicability of the three types of probes in the real situation, the Korteweg-de Vries(KdV) two-dimensional solitary wave is simulated. The wire-wire probe is strongly affected by the installation direction of the two wires; when the wires are installed perpendicularly to the flow direction, the wire-wire probe shows large distortion of the solitary wave. In order to measure the transverse profile of waves, the wire-wire probes and the flush-wire probes are required to be separately installed 2mm and 2mm, respectively.

• 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.

• 한국의학물리학회:학술대회논문집
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• 한국의학물리학회 2002년도 Proceedings
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• pp.474-477
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• 2002

Equipment to cauterize tumors by an electrically heated Kanthal wire is under development. The wire( alloy of iron, chromium and Aluminum) keeps sufficient strength up to 1400 degrees in Celsius. Although AC 50Hz current source is used in the prototype experiment, RF current will be used in future. The diameter of the Kanthal wire was 0.3 mm which was connected to Kanthal wire of 0.8 mm. The thicker wire was used as a leading wire. The possibility of application of the heating wire in combination with an ultrasound endoscope was determined, where ultrasound endoscope is to be used to monitor the location on the wire and an extent of a tumor in digestive organs. This procedure requires the wire to be applied inside ultrasound transmitting media. First, the wire was applied in the degassed water in which a chicken liver sample was submerged. The wire, however, burned out in water soon after it became red-hot at 12 A. The reason is that large current is required for the wire to become red-hot due to strong convection. Starch paste of 3 weight percent was employed instead of water. This made the wire red-hot approximately at 6 A, showing the increased viscosity of the starch decreased the convection and the wire was cover by the steam. The liver sample was cauterized successively, while the location of the wire and the liver was monitored by an ultrasound diagnosis equipment outside the plastic vessel of the starch paste.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.1059-1060
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• 2013

• 한국분말재료학회지
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• 제11권1호
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• pp.60-68
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• 2004

Pulsed wire evaporation (PWE) method is known as the promising production-technique for nanopowders. In this study, we developed and modified the previous single wire explosion equipment to the simultaneous two-wire explosion one for the fabrication of alloy or mixture of nano metallic powder. First of all, both the theoretical and empirical background of pulsed wire explosion of single wire were summarized, and compared with our experimental results for Cu and Al single wlre explosion. After then, the simultaneous wire evaporation equipment was designed, constructed, and tested. The current and voltage behavior were well matched between the calculated ones from the circuit equations, and the experimental results from simultaneous explosion of Cu and Al wire.

• 소성∙가공
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• 제29권2호
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• pp.97-102
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• 2020

Wire drawing is a metalworking process used to reduce the cross-section of a wire by pulling the wire through multi-stage drawing dies. The aim of this study is to fabricate a drawing wire using 2 stage drawing process. The finite element analysis of wire drawing was conducted to validate the efficiency of the designed process and the experiment was performed to validate the designed wire drawing process using 2 stage tungsten carbide die. Dry lubricant with powder was applied for producing a wire of desired diameter. Finally, a drawing wire using 2 stage die for cold rolling mill was developed.

• 한국기계가공학회지
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• 제13권2호
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• pp.35-40
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• 2014

Wire drawing is aplastic deformation process that produces a wire with a desired diameter by pulling the end of the wire through a die. During the cold wire drawing process, the temperature between the wire and the die bearing is increased. This temperature increase causesenergy consumption increase, bad wire quality, and decreased die life. To reduce friction and avoid high temperature between the wire and the die in the cold wire drawing process, a dry lubricant with soap particles is used. It is not possible to reused the lubricant onceiron oxide is attached to the soap particlesat high pressure die. In this study, recycling technologies for wasted soap particles with processes of crushing, separation, and screening are developed. From the evaluation, the recycling efficiency was found to be 86.97%.