• Smart Structures and Systems
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• v.5 no.3
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• pp.279-290
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• 2009

Two degrees of freedom resonant systems are employed to improve the resonant property of resonant sensor, as compared to a single degree of freedom resonant system. This paper presents design, development and testing of two degrees of freedom resonant sensor. To measure absolute mass, cantilever shaped two different masses (smaller/absorber mass and bigger/drive mass) with identical resonant frequency are mechanically linked to form 2 - Degree-of-Freedom (DOF) resonator which exhibits higher amplitude of displacement at the smaller mass. The same concept is extended for measuring differential quantity, by having two bigger mass and one smaller mass. The main features of this work are the 3 - DOF resonator for differential detection and the microcontroller based closed loop electronics for resonant sensor with piezoelectric sensing and excitation. The advantage of using microcontroller is that the method can be easily extended for any range of measurand.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.510-512
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• 2009

A volumetric 3D display system based on a rotating two dimensional color LED array is set up. It has a cylinder display space ${\Phi}800{\times}640mm3$ which is composed of 256 slices of pictures in one 3D image with each slice $320{\times}256$ LED pixels. The volumetric image has 4 gray scales and 64 colors. The main structure and working principle of the system is described in detail.

• Proceedings of the KIEE Conference
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• 1999.07a
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• pp.157-159
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• 1999

We are analyzed the characteristics of maximum thrust and normal force for new model of HB typed LSM by using Finite Element Method and Virtual Work Method. As a result of this paper, it is confirmed that maximum thrust of the enhanced LSM increased 30% without increasing the input energy and the normal force.

• Proceedings of the KIEE Conference
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• 1995.07b
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• pp.682-684
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• 1995

The most effective way to improve the performance of a fuzzy controller may be to optimize look-up values. Look-up values are derived from processes used input-output scale factors, membership functions, rule base, fuzzy inference method and defuzzification. It is powerful way to modify or organize look-up table values. In this paper, We propose the look-up values self-organizing fuzzy controller(LSOFC). We use the plus-minus tuning method(PMTM), scanning values through the processes of addition and subtraction. We show the efficiency of this LSOFC by the results of simulation for nonlinear time-varying plant with unmodelled dynamics.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2033-2035
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• 2001

본 연구는 기존의 자전거에 전기 구동장치를 장착시켜서 자전거의 페달링에 의하여 검출된 답력을 이용한 보조 동력 구동장치에 대한 개발이다. 답력의 검출은 불시의치차를 이용한 동력 전달장치를 이용하였다. 이 장치의 입력기어에서 출력기어로 동력을 전달하는 아이들 피니언 기어와 결합된 캐리어를 동력 전달시 발생하는 반력에 의한 각도를 이용하여 토크량을 측정하였다. 동력전달을 할 경우 발생하는 반력에 의한 회전각을 자기센서를 이용하여 답력을 측정하였다. 이 답력을 구동회로에 인가하여 보조동력을 자전거에 인가함에 따라 주행을 쾌적하게 하도록 개발하였으며 실험을 통하여 실용성을 고찰하였다.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2264-2266
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• 2001

In this paper, some suspension results for a magnetic suspension system with permanent magnet are presented. The electromagnetic model using the equivalent magnetic circuit is shown. And some control simulation results using Matlab/Simulink S/W are presented.

• Proceedings of the KAIS Fall Conference
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• 2004.11a
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• pp.230-233
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• 2004

CAMAC, PLC, DAQ나 GPIB와 같은 여러 인스트루먼트 인터페이스의 통합은 산업전반에 걸쳐서 널리 활용되고 있으며 이를 통하여 작업 효율 및 성능을 향상시킬 수 있다. 이를 지원하는 기술에는 여러 가지가 있지만 그 중에서 Virtual Instrumentation이 개발의 신속성 및 사용의 용이성 측면에서 타 기술을 압도하고 있는 추세이다. Virtual Instrumentation을 통한 시스템 통합에 있어서 현재 적용되고 있는 새로운 기술로서 XML을 들 수 있는데 이는 사용자와 인스트루먼트간의 통신뿐만 아니라 해당 정보 공유에 있어서 탁월한 기능을 제공한다. 본 논문에서는 이를 위하여 Virtual Instrumentation 시스템 설계에 있어서 XML 기술을 적용하고자 하면 이를 통하여 한층 진보된 시스템 설계를 제안하고자 한다.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2230-2232
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• 2003

One of the important problems in a control system design is the requirement that the system should have adequate relative stability. In this paper, We proposed a tuning algorithm PI controller for first order plus dead time system. It is determined the domain of the PI control parameters by Routh - Hurwitz criterion, and we tune parameters of the PI controller using genetic algorithm. A numerical example is also given to illustrate the method.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.949-952
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• 1996

The ultrasonic motor(USM) has good characteristics such as compact size, silent motion, low speed, high torque and high speed response. The USM is driven by 2-phase AC electricity. The control parameters of USM are voltage, phase difference, frequency of input power, etc. In this paper, we propose voltage difference control. And we designed USM controller to adjust voltage and phase using pLSI(programmable Large Scale Integration). Voltage difference control has many advantages that are lower current, lower power than phase difference control. Especially there is nearly zero ampere at the zero point of speed and torque. we can apply this voltage difference control to the compliance control of DD manipulator.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.4
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• pp.561-568
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• 2010

Instrumentation radar in a test range has an important role to measure target's TSPI(time, space, position, information). It is well known that it tracks a target stably using a beacon mode. But it may fail to track a target in a certain region using a beacon mode. In this paper, we modeled a simple missile shape similar to ATCMS with two beacon antenna and analyzed an antenna radiation pattern using MLFMM(Multi Level Fast Multipole Method) method. Using the analyzed result of the radiation pattern of the antenna and the attitude data of target, we simulated beacon tracking performance of an instrumentation radar. As a result of simulation, we showed that an instrumentation radar may lose the target because it tracks a area of the beacon antenna pattern.