• Smart Structures and Systems
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• 제25권2호
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• pp.229-240
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• 2020

In this research, toggled actuator forces were examined. For achieving to this object, an actuator was installed in a toggle pattern in a S.D.O.F frame and actuator forces were investigated thru a numerical analysis process. Within past twenty years, researchers tried to use strong bracing systems as well as huge dampers to stabilize tall buildings during intensive earthquakes. Eventually, utilizing of active control systems containing actuators to counter massive excitations in structures was emerged. However, the more powerful earthquake excitations, the more robust actuators were required to be installed in the system. Subsequently, the latter process made disadvantage to the active control system due to very high price of the robust actuators as well as their large demands for electricity. Therefore, through a numerical process (Part I), influence of toggled actuator pattern was investigated. The algorithm used in the system was LQR and ATmega328 was selected as a control platform. For comparison, active tendon control system was chosen. The final results show clearly that using the toggle pattern mitigates the required actuator forces enormously leading to deploy much lighter actuators.

• 한국전기전자재료학회논문지
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• 제18권12호
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• pp.1124-1128
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• 2005

New piezoelectric actuator design, which can reduce the number of the stacking layer without lowering the piezoelectric displacement, is suggested in this work. Each layer of the new designed multilayer actuator has the same electrode pattern as the cross-sectioned layer of the existing multilayer actuator has. The piezoelectric displacement was calculated by Finite-Element Method (FEM) analysis. The maximum piezoelectric displacement of the new-designed actuator with 13 layers was calculated to be almost same value (55.9 ${\mu}m$) as that of the existing actuator with 25 layers(60.1 ${\mu}m$).

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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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).

• 전기전자학회논문지
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• 제23권2호
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• pp.517-523
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• 2019

최근 운전자와 승차자의 편안함을 제공할 수 있는 기능을 보유한 자동차 시트에 대한 연구가 마사지 기능을 갖는 자동차 시트를 포함하여 다양한 분야에서 수행되고 있다. 마사지 효과는 시간, 크기, 형상과 같은 마사지 패턴에 의존한다. 본 연구에서는 차량용 마사지 시트의 구동장치로 사용되는 선형모터 액츄에이터와 액츄에이터의 효율향상 설계를 위한 전자기해석 및 시뮬레이션 기법을 제안하였다. 선형모터 액츄에이터 설계에 유한요소 기법을 적용하여 전자기 해석을 수행하고, 액츄에이터의 수식모델을 사용한 시뮬레이션을 통해 두드림 마사지 패턴 구현을 위한 전압 파형을 도출하였다. 제작된 액츄에이터와 제어기를 차량용 마사시 시트에 장착하여 마사지 패턴 생성에 대한 성능검증을 통해 개발된 액츄에이터의 적용 가능성을 확인하였다.

• 한국정밀공학회지
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• 제20권7호
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• pp.120-127
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• 2003

A novel three degrees of freedom sensing method utilizing binary grid pattern image and vision camera is presented. The binary grid pattern image is designed by Pseudo-Random Binary Arrays and referenced to encode in-plane position of a moving stage of the contact-free planar actuator. First, the yaw motion of the stage is detected using fast image processing and then the other planar positions, x and y, are decoded with a sequence of images. This method can be applied to the system that needs feedback of in-plane position, with advantages of a good accuracy and high resolution comparable with the encoder, a relatively compact structure, no friction, and a low cost. In this paper, all the procedures of the above sensing mechanism are described in detail, including simulation and experiment results.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1810-1814
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• 2008

A small L-type megasonic module for nano-pattern cleaning was designed and manufactured. The impedance graph of the quartz waveguide with a piezoelectric actuator was predicted using finite element method (FEM). The peak value of the piezoelectric actuator alone was 3.373 MHz, which was the same as the experimentally measured value of 3.373 MHz (0.0% error). In addition, the maximum impedance value of the quartz waveguide with the actuator was 3.373 MHz, which agreed well with the measured value of 3.362 MHz (0.3% error). The acoustic pressures of a conventional megasonic system (3 MHz) and the developed system under similar conditions were measured and compared. The results showed that the maximum values and standard deviations of the developed system decreased by 29% and 18%, respectively, compared with the conventional type. This suggests that the small L-type would have higher particle removal efficiency with lower possibilities of pattern damages.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.147-149
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• 2007

This paper presents design results of anultra-small actuator for auto focus or optical zoom function of mobile phone cameras. The consideration of the actuator is tubular type having a large hole in its center to arrange some optical lenses. The stator consists of 3-phase windings, and the mover is designed to an Nd injection permanent magnet(PM) which magnetized with multi-pole polar pattern. From the numerical analysis that taking into account the magnetizing pattern of the PM, the thrust of the designed actuator is about 40mN with the outer diameter of 7mm.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.362-365
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• 2004

'Coil' occupies a much important position in delivering driving force of optical pick-up actuators. Up to now the main stream has been a winding coil type actuator, but actuators using FP-Coil(Fine Pattern Coil) have been considered for the more compacted and simple manufacturing process and have variously spreaded the application fields by product. We have tried to design actuators using PCB-Coil(Printed Circuit Board Coil) which has benefits in terms of price and manufacturing process. Especially this research has two main things those are to reduce the vibration of sub-resonance and to assure the do sensitivity in the performance of asymmetric optical pick-up actuator with PCB-Coil.

• 한국안전학회지
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• 제28권3호
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• pp.69-73
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• 2013

The purpose of this paper is to analyze the carbonization pattern and operation characteristics of an MCCB. The MCCB is consisted of the actuator lever, actuator mechanism, bimetallic strip, contacts, up and down operator, arc divider or extinguisher, metal operation pin, terminal part, etc. When the actuator lever of the MCCB is at the top or the internal metal operation pin is in contact with the front part, the MCCB is turned on or off. It means trip state if the actuator lever or the internal metal operation pin moves to back side. In the UL 94 vertical combustion test, white smoke occurred from the MCCB when an average of 17~24 seconds elapsed after the MCCB was ignited and black smoke occurred when an average of 45~50 seconds elapsed. It took 5~6 minutes for the MCCB surface to be half burnt and took an average of 8~9 minutes for the MCCB surface to be entirely burnt. In the UL 94 test, the MCCB trip device operated when an average 7~8 minutes elapsed. If the MCCB trip has occurred, it may have been caused by an electrical problem such as a short-circuit, overcurrent, etc., as well as fire heat. From the entire part combustion test according to KS C 3004, it was found that the metal operation pin could be moved to the MCCB trip position without any electrical problems.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1999년도 학술발표대회 논문집 제18권 2호
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• pp.237-242
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• 1999

In this study, a design method using plane actuator is developed to make new speaker system, whose shape is much thinner than that of conventional loudspeaker. Piezofilm(PVDF) is used as plane actuator of flat speaker. To avoid the distortion of sound radiated from flat speaker, the frequency response of radiated sound to be flat is taken as the design objective. The electrode pattern and orientation angle of piezofilm actuator is optimized to satisfy the design objective. The formulation is based on the coupled finite element and boundary element method. Genetic algorithm is used in the optimization process, which is useful in the optimization of discrete design variables. Frequency response with optimized piezofilm actuator is made flat enough to satisfy the design objective. For the enhancement of sound power, double-layered piezofilm actuators are also considered. The sound power with double-layered actuator becomes larger than that with single-layered actuator as expected.