• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.04a
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• pp.99-104
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• 2004

Micro/meso cutting is getting more important in the fields of precision machining technology. A micro-turning lathe is one of parts to consist the Micro Factory. It accepts stepwise motion actuators that are used for feeding system instead of the conventional mechanism. It is consisted of two Piezoelectric ceramics; one is for feeding the slider, and the other is for clamping the slider in the guide way of the body. The linearity and positional accuracy of the actuators are good enough for high precision motion. The spindle unit is operated with DC motor on the top of the slider. The motion is communicated with miniaturized linear encoder attached on each side of axis. A mono crystal diamond tool is used for cutting tool. This micro-lathe has been made a machining experiment to see the characteristics of micro-machining.

• Proceedings of the KIEE Conference
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• 1993.11a
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• pp.207-209
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• 1993

In this paper, an electrostatic silicon micro actuator has been designed and fabricated using the micro machining technology. The actuator consists of two counter electrodes. One is an Al film deposited on a pyrex glass, and the other is a circular corrugated diaphragm with boron doped. The diaphragm is fabricated by boron etch stop technique using an anisotropic etchant, EPW.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.7 s.94
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• pp.1731-1739
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• 1993

An application of Scanning Tunneling Microscopy(STM) is investigated for the measurement of 3-dimensional profiles of the macro-machined patterns of which critical dimensions lie in the range of submicrometers. Special emphasis of this investigation is given to extending the measuring ranges of STM upto the order of several micrometers while maintaining superb nanometer measuring resolution. This is accomplished by correcting hysteresis effects of piezoelectric actuators by using non-linear compensation models. Detailed aspects of design and control of a prototype measurement system are described with some actual measuring examples in which fine It patterns can successfully be traced with a resolution of 1 nanometer over a surface range of $4{\times}2$ micrometers.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1793-1797
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• 2003

After the micro turning lathe was developed in the last year by AMR Laboratory in Yeungnam university, a micromilling machine is developed for micro/meso machining. This machine is integrated with PZT-driven micro-sliders, micro-linear encoders, aerostatic spindle which has maximum 150,000 rpm. It is applicable to milling and drilling of micro scale. This paper presents the possibility of micro/meso machining and characteristics of micro end milling process by using micro machine. A machining of micro parts using 0.2 mm flat end mill was achieved by micro-milling machine. Experimental results show the machining capability and positional accuracy of this machine is good enough for machining micro parts.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.220-225
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• 2003

Recent issue of optical actuator is applying to mobile device. It leads actuator to become smaller than conventional type. This paper proposes the design of micro actuator plate spring and analysis of its vibration characteristic. Considering natural frequency of spindle motor, 1st and 2nd eigenfrequency of micro actuator must avoid its natural frequency. First, magnetic circuit is designed by using fine pattern coil and magnetic force is acquired by simulation program. Then, concept design is achieved by topology optimization. From concept design, micro actuator plate spring is embodied through DOE(design of experiment). Finally, considering vibration characteristic simultaneously, optimal plate spring design is determined by RSM(response surface method).

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.283-286
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• 2002

This paper presents the straightness compensation system which is a device for improving the machining accuracy of ultra-precision machines by synchronizing the position of diamond tool tip with machine error motion. Sine it is actuated by piezoelectric actuator with highly nonlinear hysteresis characteristics, the feedback control schemes such as Proportional Integral(PI), are required and realized by measuring the displacements of diamond tool tip. for the better tracking performance, the controller was implemented using TMS320C32 32bit floating-point DSP which is fast so that the real-time control is possible. In addition, stand alone type DSP board was chosen fur the easy assembly into the ultra-precision machines. The experimental results show good command tracking performance and the motion error of the machine is satisfactorily compensated during the machining process.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2372-2373
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• 2005

The design of a piezoelectric actuator for micro droplet ejecting system has bee studied. The actuator has been evaluated by using commercial FEM package and its displacement are measured by LDV(Laser Doppler Vibrometer). The characteristics of the actuator are evaluated with varation in a ratio of width of PZT to that of membrane and thickness ratio of PZT to membrane.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.558-559
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• 2018

The harness wiring serves as an intermediary for transmitting the electrical signals necessary to drive the vehicle and is highly influenced by vehicle performance. Wire harness tester performs assembly test. Harness products are operated with the function of checking 0 and 1. Proceed to inspection in wire assembly process. There is a defect in the finished vehicle during use. We want to improve such defects. We design the FPGA and propose the measurement device design and the simulation result that the line and the line are disconnected by ADC precision harness inspection.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.218-218
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• 2008

최근 미관을 위하여 소형 네온관 등이 사용되고 있다. 따라서 네온관 등 구동에 사용되는 인버터는 안정기 역할을 하면서 소형화와 경량화가 중요한 요소이다. 본 연구는 압전 특성이 우수한 PZT계 세라믹스 조성인 $(Pb_{0.94}Sr_{0.06})[(Ni_{1/2}W_{1/2})_{0.02}(Mn_{1/3}Nb_{2/3})_{0.07}(Zr_{0.51}Ti_{0.49})_{0.91}]O_3$에 특성 향상을 위해 PbO, $Fe_2O_3$, $CeO_2$, Xwt% $Nb_2O_5$ 조성별로 첨가하였으며 그에 따른 유전, 압전 특성을 조사하고 또한 Rosen type의 압전 트랜스포머를 제작하여 각 조성별 변환효율을 측정하였다. 실험방법은 일반적인 세라믹스 제조공정으로 파우더 혼합 후 24시간 ball milling하고 $850^{\circ}C$ 에서 2시간 하소 후 $1230^{\circ}C$에서 2시간 소결하였다. 또한 최종 소결 시편을 이용하여 Rosen type의 압전 트랜스포머를 제작하였다. 상 분석을 위해 XRD를 이용하여 perovskite구조를 확인하고 미세구조확인을 위해 SEM으로 관찰하였다. 압전 특성을 평가하기 위해 압전 $d_{33}$ Meter를 사용하였으며, Impedence analyzer HP 4194A를 이용하여 전기적 특성을 측정하였다.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.102-102
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• 2017

제주산 감귤생산량은 51만톤(2016년)으로 수확기에 장마 등과 같은 환경적 요인에 의해 결점과의 비율이 24.9% 정도이다. 결점과로 통칭되는 비상품과는 일부 대기업의 쥬스공장에서 수매하는 량을 제외한 대부분은 자체 농장에서 폐기처분되고 있어 많은 감귤 비상품과 처리에 많은 문제점이 노출되어 오고있다. 성주군에서는 결점과 및 비상품과가 시장에 출하되는 것을 방지하기 위하여 자체 수매하여 액비, 발효퇴비, 사료화 가공 등에 많은 비용을 투자하고 있다. 따라서 본 연구는 당도가 15 Brix에 달하는 고당도 감귤 및 참외의 비상품과를 효과적으로 착즙하여 감귤 착즙액은 생산농자재로 환원하고, 참외 착즙액은 참외조청용 원료로 사용하는 기술을 개발하고자 한다. 착즙장치는 PLATE형 스크류, 테퍼 스크류 하우징, 파쇄된 과즙을 마지막 단계인 압입하는 고깔부 및 동력을 공급하는 구동부로 구성하였다. 개발한 고액분리 착즙장치의 외형은 $W1,000{\times}L2,000{\times}H1,070$이고 사용동력은 0,75kw, 1/30 감속모터를 사용하였다. 일반적인 착즙장치는 1단 분쇄와 동일 원통형의 스크류 압착으로 고액분리를 위한 착즙이 이루어지기 때문에 처리량이 150kg/hr에 불과하지만 개발한 고액분리장치는 2차 분쇄와 원통형과 원추형의 스크류 압착 후 고액분리망을 통과하도록 하여 500kg/hr 이상을 착즙이 가능하도록 개발하였다. 따라서 농산물의 고액분리를 통한 농산물의 가공을 위한 연속 착즙 장치는 2단 분쇄와 원통형 및 원추형 압착 미세망을 이용한 고액분리 착즙기는 기존 착즙기에 비하여 처리량이 3배 이상 증가되었다는 것을 알 수 있었다. 기존 감귤 착즙기의 수율은 60%정도이나 개발 착즙기의 착즙 수율은 66.5%로 나타나 본 연구에서 개발한 착즙기의 수율이 기존 착즙기의 수율보다 약간 높게 나타났다. 기존 착즙기는 원료(농산물의 종류)의 종류나 전처리에 제한이 있어 전용으로 사용하는데 비해 본 연구에서 개발한 고액분리 착즙기는 원료의 종류나 전처리 상태에 관계없이 사용 가능함을 확인하였다.