• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2018년도 공동국제학술발표회
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• pp.31-31
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• 2018

• 대한기계학회논문집
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• 제17권9호
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• pp.2234-2241
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• 1993

The torque variation in drilling process represents the problems of the efficient and stable machining. In order to cope with them, the active control method is adopted to drill the workpiece under the constant cutting torque though the cutting stiffness of the workpiece or the diameter of the drill bit changes. The cutting process is modeled in the geometric viewpoint related with the feed and the number of cutting lips. And the dynamic model is approximated to the first order system for the purpose of control. The adaptive PI control is used in computer simulations and experiments. The results of the study show the validity of the drilling method with torque control.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.993-998
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• 2002

watches, air bearings and printed circuit hoards (PCB). However, it is not easy to determine optimum cutting conditions since the micro drilling process is very sensitive to various disturbances. Also, undesirable characteristics to optimize the micro drilling are small signal-to-noise ratios, drill wandering motions and high aspect ratios. Thus, in this study, experimental design methods are applied to determine optimum cutting conditions. Suing the methods, three cutting parameters, fred, step and curving speed are optimized to minimize thrust forces. Obtained conditions are verified through required experimental works. As the results, it is shown that the experimental methods can be applied to micro drilling processes to determine Optimum Cutting Conditions.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.926-931
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• 2002

Although ceramic plates with many micro-hales are used as MCP (Micro-channel plate) for electron amplification, catalytic converters, filters, electrical insulators and thermal conductors in integrated circuits, the drilling of micro-hales in the ceramics is difficult because of their low thermal conductivity, high hardness and brittleness. Therefore, in this work, the machining of ceramic green body fellowed by sintering of green body was employed fur fabricating ceramic plates with many micro-holes. The micro-drilling of alumina green body was performed with diamond abrasive WC drills, and the cutting force w.r.t. drilling times was measured for the determination of toot life. From the investigation of the wear of micro-drill tip w.r.t. drilling times, the wear mechanism of tip during micro-drilling of ceramic green body was suggested.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1555-1558
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• 2005

In this study, we measured cylindricity and Runout of the air bearing spindle, and tested PCB(printed circuit boards) drilling with 0.4mm micro drill at 90,000rpm and 110,000rpm in order to obtain drilling hole error. Results are as follows; The air bearing spindle's Runout was not so high within $10\mu{m}$ from 20,000rpm to 80,000rpm but it grew after 80,000rpm. Drilling hole size error was 9% at 80,000rpm and 12% at 110,000rpm because of spindle's Run out. Drilled hole shape falsified more 110,000rpm than 90,000rpm.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.740-744
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• 2002

This paper describes the design and development of drills with deburring inserts. The drills can be used to drill holes and deburr the edges of the drilled holes simultaneously. The drills incorporate deburring inserts within the shank. The insert consists of a fixing base, a cantilever spring and a cutting tip. The stiffness of the cantilever spring and the details of the cutting tip play a central role for the successful deburring performance. The deburring performance is also governed by the conditions of the drilling burr best described by the burr control chart suggested by Dornfeld. With careful burr control, successful deburring is obtained by the drills with deburring inserts.

• International Journal of Precision Engineering and Manufacturing
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• 제8권1호
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• pp.11-15
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• 2007

Composite materials are widely used to make all kinds of machine parts, internal and structural materials of cars, aerospace components, building structures, ship materials, sporting goods and others, It is worth while to use composite space substitute material in various applications when compared with others. But the use of composite material is limited in the field of the mechanical processing because of the difficulties in processing. Thus, it is proved that the surface is rough at the in and out sections of the hole processing when the GFRP is machined with HSS drill in the vertical machining center. And it is observed that the more it is processed, the more the fluid type long chip is changed into the powdered chip.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2001년도 추계학술대회 논문집
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• pp.403-406
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• 2001

eBusiness 환경속에서 기업들의 주요한 관심사는 eSCM 통합을 통한 경쟁력 획득에 있다. 파트너쉽에 기반한 성공적인 eSCM 통합을 이루고, 궁극적으로는 고객 만족을 달성하기 위해서는 eSCM에 대한 참여 기업 간 공동 성과 측정 시스템을 만들고, 이를 통해 공급사슬 통합에 관련된 비용/효과에 대해 명확하게 이해하도록 하는 것이 핵심이다. 이러한 참여 기업들 사이의 공동의 성과 측정시스템을 활용하기 위해서는 재무적 그리고 비재무적 성과 사이의 균형을 성취하기 위한 강력한 도구인 Balanced Scorecard와 eSCM의 연계에 기반한 드릴다운(drill-down) 방식의 성과 측정을 통해 공급사슬의 다른 수준에 대한 성과 측정이 이루어져야 한다. 본 연구에서는 BSC와 eSCM의 연계를 위해 BSC를 eSCM관점에서 재정립하고, 드릴다운(drill-down)방식에 기반한 eSCM 성과 측정 시스템 활용을 위한 기본 틀을 제시하고자 한다.

• 대한기계학회논문집
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• 제18권12호
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• pp.3175-3184
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• 1994

The high strength and wear-resistant metal bonded diamond wheel was applied to the drilling process of carbon fiber reinforced plastics (CFRP), The helical-feed drilling method was use for the first time to overcome the limit of drilling depth of the conventional drilling process and to improve the dressing of the wheel. The helical-feed drilling method was found effective at high cutting speed without the limit of drilling depth.

• 한국기계가공학회지
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• 제10권4호
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• pp.82-87
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• 2011

Lubrication has an important role to reduce frictional forces and temperature between cutting chips and the face of a tool. However, it has harmful effects to workers' health and working environment. The purpose of this thesis is to find cutting conditions through the quality analysis in boring for SM45C steel using MQL(Minimum Quantity Lubrication). Machining process is super drill, tip drill, end mill and boring in order. Experimental factors of boring and the quantity of mist air are properly selected. With the analysis of experimental data, this thesis shows that boring with MQL improves the surface roughness when spindle speed is 934rpm or feeding speed is 74mm/min.