• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.894-899
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• 2004

In this paper, the track pull-in behavior analyses in an optical disk drive (ODD) using plane phase is treated and the parameters affecting it are discussed. Track pull-in is the track capture procedure to do track following control and it is key factor to increase data transfer rate. Simulation method, Runge-Kutta method to solve nonlinear equation, is used to evaluate the track pull-in conditions, and the real servo loop parameters are applied in this process to get the more real condition. Finally, the comments for the acquired results are discussed briefly.

• International Journal of Precision Engineering and Manufacturing
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• 제2권4호
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• pp.30-39
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• 2001

This paper investigates vibrational motion of a flexible beam fixed on a moving cart and carrying a moving mass. The equations of motion of the beam-mass-cart system are analysed through the unconstrained modal analysis. The exact normal mode solution used in modal analysis correspond to the eigenfrequencies for each position of the moving mass and to the ratios of the weight of the beam-mass-car system. Time solutions of normal modes are also transformed properly according to the position of the moving mass. Numerical simulations are carried out to obtain open-loop responses of the system in tracking pre-designed paths of the moving mass. The simulation results show that the model predicts the dynamic behavior of the beam-mass-cart system well. Experiments are carried out to show the validity of the proposed analytical method.

• 전자공학회논문지A
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• 제32A권5호
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• pp.1-13
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• 1995

In this paper, we evaluated the mean acquisition time and it's variance of the rapid synchronization system using the DMF(Digital Matched Filter) under the DS/CDMA system which uses the long period PN code. And we implemented the synchronization system that satisfies the specification demanded by the proposed EIA/TIA Interim Standard of Qualcomm Company. We showed that the state of the PN spreading code was estimated using the DMF(Digital Matched Filter) and then exact and fast chip synchronization could be achieved by the early-late tracking loop in the multiple channel environment. And we suggested the possibility that this synchronization system could be useful in the emerging digital cellular DS/CDMA system.

• 전자공학회논문지S
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• 제35S권1호
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• pp.122-129
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• 1998

For generation and analysis of the multi-sensory image, we propose a new three dimensional (3D) modeling method considering an iternal heat source. We represent the heat conduction process within th object as an equivalent thermal circuit. Therefore, without a complex computation, our modeling approach can obtain thermal features of the object. By using the faceted model, the proposed method can express the accurate visual signatures of the object. Comparing the estimates datum with the obtained surface temperatures, we have demonstrated that the proposed method can provide a precise thermal features. The thermal images by out model is applicable to simulate a tracking loop of an IR missile.

• 전기학회논문지
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• 제61권3호
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• pp.361-366
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• 2012

This paper analyzes the THD(Total Harmonics Distortion) according to output power fluctuation of photovoltaic(PV) systems using real time simulator. For being close to reality, the PV system including inverter and MPPT(Maximum Power Point Tracking) which composed of closed-loop using real-time simulator are modeled. The change of irradiance and temperature of PV module is modeled to consider the change of weather. The various simulations according to the weather conditions are performed and THD is calculated at each condition. In this paper, the results by off-line simulation are compared with the ones of real time simulation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1533-1534
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• 2008

회전 항체용 GNSS(Global Navigation Satellite System) 수신기의 회전 추적 루프를 제안하였다. 제안하는 회전 추적 루프는 항체의 회전속도와 회전각을 추적하는 회전 추적 루프가 반송파 추적 루프에 추가되는 형태이다. 회전 추적 루프에서 수신기의 상관기 출력값을 이용하여 항체의 회전 속도를 추정하고 이를 이용하여 회전 변조된 반송파의 위상과 주파수를 추적할 수 있도록 하였다. 제안하는 GNSS 수신기의 회전 추적 루프는 모의실험을 통하여 검증하였으며, 이 루프를 사용함으로써 회전 변조된 신호를 GNSS 수신기에서 추적할 수 있음을 확인하였다.

• 전기학회논문지
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• 제66권4호
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• pp.666-671
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• 2017

A disturbance-observer-based adaptive neural tracker design problem is investigated for a class of perturbed uncertain non-affine nonlinear systems with unknown control direction. A nonlinear disturbance observer (NDO) design methodology using neural networks is presented to construct a tracking control scheme with the attenuation effect of an external disturbance. Compared with previous control results using NDO for nonlinear systems in non-affine form, the major contribution of this paper is to design a NDO-based adaptive tracker without the sign information of the control coefficient. The stability of the closed-loop system is analyzed in the sense of Lyapunov stability.

• Journal of Mechanical Science and Technology
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• 제18권3호
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• pp.337-346
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• 2004

The control scheme using fuzzy modeling and Parallel Distributed Compensation (PDC) concept is proposed to provide asymptotic tracking of a reference signal for the flexible joint manipulators with uncertain parameters. From Lyapunov stability analysis and simulation results, the developed control law and adaptive law guarantee the boundedness of all signals in the closed-loop multi-input/multi-output system. In addition, the plant state tracks the state of the reference model asymptotically with time for any bounded reference input signal.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.1018-1023
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• 1998

This paper presents an effective control scheme incorporated in the voltage-fed half-bridge series resonant inverter for induction heating applications, which is based upon a load-adaptive tuned frequency tracking control strategy using PLL(Phase Locked Loop) and its peripheral control circuit. The proposed control strategy ensures a stable operation characteristics of overall inverter system and ZVS(Zero Voltage Switching0 operation in spite of sensitive load parameters variation as well as power regulation, specially in the non-magnetic heating loads. The simulation results and the performance characteristics in the steady-state are shown as compared with the experimental results for a prototype induction cooking system rated at 1.2kW.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.7-10
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• 1998

Because of simple control algorithm and easy implementation, the conventional PI controller has been widely used in industrial application. But, it is very difficult to find the optimal PI control gain. Therefore, in improperly tuned PI controller or parameter variation, to obtain optimal performance, the novel PI controller, which consist of conventional PI controller and 4-rule based fuzzy logic, are presented in this paper. The novel PI controller which exhibits a stabilizing effects on the closed-loop system, has good robustness regarding the improperly tuned PI controller or parameter variation. The simulations are performed to verify the capability of proposed control method on induction motor.