• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 춘계학술대회 논문집
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• pp.894-897
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• 2000

본 연구에서는 초미세 형상부품의 제작기술로서 방전가공기술의 활용을 전제로 하여, WEDG(Wire electric discharge grinding: WEDG)가공에 있어서 가공액의 공급방식을 포함한 공급환경이 표면상태에 미치는 영향에 관하여 조사하였다. WEDG법을 이용한 형상가공에 있어서는 단위 방전 펄스당의 에너지를 극소화하여 제거단위를 미세화함으로서 가공정밀도(가공표면 및 가공형상의 정밀도)를 향상시키는 것이 가능하다.(중략)

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.235-236
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• 2011

• 한국공작기계학회논문집
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• 제14권5호
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• pp.13-20
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• 2005

Micro EDM process is generally used for machining microholes, cavities, and three dimensional shapes. For machining micro structures, first of all, micro tool electrode is indispensable and WEDG system is proposed for tool fabrication method. When using WEDG, its machining characteristics are highly affected by many EDM parameters such as applied voltage, current, rotation speed, capacitance, and pulse duration. Therefore, the design of experiment is introduced to fully understand the effect of the EDM parameters on machining tool electrode. And an attempt has been made to develop the mathematical model for predicting the size of the tool electrode by calculating spark distance. The suggested model was verified with experiment and predicted working gap distance is in good accord with the measured value.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.953-956
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• 1997

Micro drilling characteristics by EDM method was investigated. In detail, Micro tool electrode for EDM drilling was machined by use of WEDG method and micro hole was drilled using the machined tool electrode in SUS plate. The machining accuracy and time was compared in a different dielectric fluid. As a result, it was convinced that this method could be utilized as a fabrication technology of micro mold or micro 3 dimensional parts.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2009년도 추계학술대회 논문집
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• pp.193-194
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• 2009

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 춘계학술대회논문집 - 한국공작기계학회
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• pp.246-251
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• 2000

In this paper, Wire electric discharge grinding(WEDG) method for manufacturing the micro shaft was introduced and the machining characteristics was investigated. from the experimental results, it was concluded that high surface integrity could be obtained by use of dielectric fluid spraying method and small capacitive condenser.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.1003-1007
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• 2002

Micro-EDM is generally used far machining micro 3-D structure. For micro-EDM, first of all, micro-electrode fabrication is needed and WEDG system is proposed for tool electrode fabrication method. When tool electrode is fabricated using WEDG system, its characteristics are under the control of many EDM parameters. Also relations between the parameters affect electrode fabrication. In this study, experiments are carried out to analyze effects of EDM parameters on micro-electrode fabrication. Experimental method and analysis are used to experimental design method. Factors used in experiments are composed of applied voltage, capacitance, wire feed rate, spindle rotating speed, machining time. As a result of experiments, wire feed rate, machining time and capacitance is proportional to gap distance(material removal), the other parameters(applied voltage, spindle rotating speed) and relations between the parameters have little influence on machining.

• 한국정밀공학회지
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• 제20권9호
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• pp.109-117
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• 2003

With development of high advanced technologies and skills, micro machining techniques also are being more functional and smaller. Some of the recently developed micro machining technologies are micro drilling, micro EDM, WEDG, LBM, micro milling, micro UVM etc. In these micro machining techniques, Micro -EDM is generally used for machining micro holes, pockets, and micro structures in difficult-cut-materials. For machining micro structures, first of all, tool electrode should be fabricated by WEDG process. In micro-EDM, parameters such as peak current, pulse width, duration time are very important to fabricate the tool electrode and micro structures. Developed experimental equipments are composed of RLC circuit with PWM. In this paper, using developed micro EDM machine, the characteristics of micro electro discharge machining are investigated at micro holes, slot, and pocket machining etc. Also the trends of tool wear are investigated in case of hole and slot machining.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.218-222
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• 2002

Micro-EDM is generally used far machining micro holes, pockets, and 3-D structures. For micro-EDM, first of all, micro-electrode fabrication is needed and WEDC system is proposed for tool electrode fabrication method. When tool electrode is fabricated using WEDG system, its characteristics are under the control of many EDM parameters. Also relations between the parameters affect electrode fabrication. In this study, experiments are carried out to analyze effects of EDM parameters about electrode surface integrity on micro-electrode fabrication. Experimental method and analysis are used to experimental design method. Factors used in experiments are composed of capacitance, resistance, pause time, wire feed rate, spindle rotating speed. As a result of experiments, capacitance and resistance affect electrode surface.

• 원예과학기술지
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• 제31권3호
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• pp.380-387
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• 2013

건천마와 발효천마의 추출물을 이용하여 항노화 활성과 신경성장인자 유도효과를 비교하였다. 항산화 활성을 비교하여 측정한 결과 모든 추출물에서 비교적 높은 항산화력을 나타내었으며, 발효하지 않은 건천마 추출물보다 발효과정을 거친 발효천마 추출물에서 다소 높은 항산화력을 나타내었다. Angiotensin converting enzyme(ACE)와 xanthine oxidase(XOase) 저해 활성을 측정한 결과 DW 추출에서 DPPH가 건천마 $64.14{\pm}0.89%$, 발효천마 $66.21{\pm}1.03%$으로 나타났고, ABTS가 건천마 $54.15{\pm}1.37%$, 발효천마 $60.24{\pm}2.25%$로 나타났다. 70% EtOH추출에서도 유사한 결과를 보여 발효천마 추출물이 ACE에 대해 높은 저해활성을 나타내었으나, XOase에 대하여 발효 및 건천마 추출물의 차이는 크지 않다는 것을 알 수 있다. 그리고 nerve growth factor (NGF) 활성 측정 결과 모든 추출물에서 40%의 신경돌기 성장효과를 나타내었다. 이와 같이 건천마와 발효천마의 추출물을 상대로 천마의 항노화 활성과 신경성장인자 유도효과에 대한 기능성을 탐색한 결과 발효천마가 건천마보다 우수한 생리기능성을 가지는 것을 알 수 있어, 발효과정을 통하면 천마의 활용도를 높일 수 있다는 것을 증명할 수 있었다.