• 한국기계가공학회지
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• 제11권5호
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• pp.99-103
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• 2012

Presently, A glass is widely used in telecommunication system, optoelectronic devices and micro electro mechanical systems. Micro drilling of glass using the laser can save processing cost and improve the accuracy. This paper experiments micro drilling using KrF excimer laser on the pyrex glass of $500{\mu}m$ thickness. We have experiment to find out optimum laser machining conditions of micro drilling of glass and ablation depth and influence by processing parameter suc'h pulse repetition rate, energy density and number of pulses. Pulse repetition rate don't influence ablation depth at the micro drilling of pyrex glass. Energy density influence micro drilling of parallelism and maximum thickness that can be drilled. Ablation depth is most influenced by number of pulses.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.1088-1091
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• 1997

This paper describes the characteristic of hinges on which a lever pivots within a limited angle due to the torque. The hinges are exerted by the thermally expanded actuators connected with a level through hinges. To enhance the stroke of inchworm actuator, FEM(Finite Element Method) was utilized for the characterization in view of stress displacement according to the variation of notch radius and notch width. As a result, notch width of the hinges plays an important part in improvement of micro inchworm actuator.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.836-839
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• 2003

A pneumatic servo valve which is widely applied in industrial field. And It is consist of force motor, spool ＆ sleeve and servo controller. In this study. we developed the force motor which is consume to low power for a pneumatic servo valve. We could reduce the number of turn of the solenoid by using ferromagnetic permanent magnet and took different direction of each other using one coil instead of two coil. we modeled a system consisting of various electro-mechanical subsystems. The appropriateness of the model was verified by simulation. The simulation model resolved the motion of spool, the winding current and the magnetic force. Also, we calculated the displacement and velocity of the spool, flux contour line, b vector. flux density. flux linkage, back EMF etc.

• 한국생산제조학회지
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• 제23권2호
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• pp.133-137
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• 2014

The recent development of electro-optic devices and anticorrosion media has made it necessary investigate infrared optical systems with solid-solid interfaces of materials with amorphous characteristics. One of the most promising classes of materials for these purposes seems to be chalcogenide glasses, which are based on the Ge_Sb_Se system, have drawn much attention because of their use in preparing optical lenses and fibers that are transparent in the range of 3-12 um. In this study, a standard melt-quenching technique was used to prepare amorphous Ge_Sb_Sechalcogenideto be used in the design and manufacture of infrared optical products. The results of structural, optical, and surface roughness analyses of high purity Ge_Sb_Sechalcogenide glasses after various annealing processes reported.

• 한국광학회:학술대회논문집
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• 한국광학회 2000년도 제11회 정기총회 및 00년 동계학술발표회 논문집
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• pp.32-33
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• 2000

최근 디지털 정보 처리 기술의 획기적인 발전과 함께 저가의 반도체 레이저의 개발로 말미암아 광기록 장치(optical pickup device) 및 고속 광통신(optical fiber communication)분야에 응용을 위한 레이저 광학 시스템에 대한 연구가 활발하다. 광신호의 커플링(coupling) 및 스위칭(switching)을 기반으로 하는 이러한 광학 시스템은 일반적으로 광신호의 변조를 위한 광학 요소와 광학 요소의 공간적 제어를 위한 정밀 구동기로 구성되는데, 기존의 상용 시스템의 경우에는 독립적으로 기 제작된 광학 요소와 정밀 구동기를 사후에 조립하는 방법으로 소기의 목적을 달성하였다. 이와 같은 경우 제작에 많은 노력과 비용이 요구되며, 성능의 획기적인 향상을 기대하기 어려우므로 최근에는 Optical MEMS 혹은 MOEMS(Micro-Opto-Electro-Mechanical System)로 대변되는 마이크로머시닝기술(micromachining technology)을 이용한 초정밀 광학계의 제작 기술을 통하여 기존 시스템의 한계를 극복하고자 하는 노력이 다각도로 모색되고 있다. (중략)

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1468-1469
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• 2008

기상관측 분야에서는 풍속센서의 소형화 요구가 커지고 있어 Air flow sensor를 이용한 MEMS(Micro Electro Mechanical System) 풍향 풍속센서의 응용연구가 활발하다. MEMS 풍향 풍속 센서는 수 mm 크기를 가지면서도 바람의 세기와 함께 방향을 측정하여야 하는데, 센서 칩이 노출되어 있어 외부환경으로부터 영향을 받기 때문에 센서소자의 내오염성과 내구성 확보가 중요하다. 따라서 본 연구에서는 절연막으로 비점착성의 테프론 막을 적용하여 외부환경으로부터 영향을 줄일 수 있는 열감지 방식의 MEMS 풍향 풍속 센서 칩을 제작하였다. 테프론 코팅막을 이용한 풍향 풍속 센서는 0.1m/s의 resolution을 가지며, 최대 15m/s까지 측정이 가능하여, 오염에 강하고 발수성을 센서를 제작하였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1669-1673
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• 2008

In this study, we simulated the atrial arrhythmia numerically. By using electro-physiological model of atrial cell from Nygren et al. and applying reaction-diffusion partial differential equation, we simulated electrical conduction in atrium. A 3-D mesh system representing the human atrium was reconstructed from the surface geometry of atrium. We used a stimulus in the form of an archetype around pulmonary vessels in the left atrium to cause the atrial arrhythmia. The septal atrial tarchycardia was developed after the stimulus.

• 한국공작기계학회논문집
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• 제13권2호
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• pp.88-93
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• 2004

The main objective of the research is to Propose an algorithm that to estimate the screwing torque from parameters of DC motor current without using any stain gage and torque cell. The auto screw drive system is divided into two parts, one is the DC motor ind the other is mechanical part in which the friction torque and damping ratio are a function of rotational of spindle electro motive force constant. The torque is estimated from the friction torque. The research is concerned with applying the method to an auto screw drive and the advantages and limitations are also discussed in this paper.

• 한국소음진동공학회논문집
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• 제15권12호
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• pp.1355-1360
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• 2005

Periodic structures can be applied as a MEMS(micro-electro-mechanical system) sensor or actuator due to low energy loss and wideband frequency response. The dynamic behavior of a mistuned periodic structure Is dramatically changed from that of a perfectly tuned periodic structure. The effects of mistuning, coupling stiffness, and driving point on the forced vibration responses of a simple periodic structure ate investigate4 through numerical simulations. On the basis of that, one can design effective and reliable MEMS components using periodic structures.

• 한국전기전자재료학회논문지
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• 제19권11호
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• pp.1010-1013
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• 2006

Hydrogenated Diamond-like carbon (DLC) films were Prepared by the radio frequency plasma enhanced chemical vapor deposition (RF PECVD) method on silicon substrates using methane $(CH_4)$ and hydrogen $(H_2)$ gas for the application to solid lubricant of MEMS devices. We have checked the influence of varying RF power on tribological properties of DLC film. We have checked their performance as two kinds of method such as FFM (Friction Force Microscope) and BOD (Ball-on Disk) measurement. The friction coefficients and the contact number of cycles to steady state decreased as the increase of RF power with FFM and BOD measurement, respectively.