• Journal of Information Processing Systems
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• v.16 no.2
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• pp.394-405
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• 2020

The parameters of transmission lines have an influence on the electromagnetic environment surrounding the line. This paper proposes a method based on phasor measurement unit (PMU) and supervisory control and data acquisition (SCADA) to achieve online estimation of transmission line full parameters, such as resistance, reactance and susceptance. The proposed full parameter estimation method is compared with the traditional method of estimating resistance independently based on SCADA system. Then, the electromagnetic environment is analyzed based on the different parameter estimation methods. The example results illustrate that online estimation of transmission line full parameters is more accurate in the analysis of electromagnetic environment, which further confirms its necessity and significance in engineering application.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.201-204
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• 2001

In this paper, for modeling of electrical characteristics in Poly Silicon Thin Film Transistors with process parameters set up optimum values. So, the I-V characteristics of poly silicon TFT parameters are examined and simulated in terms of the variations in process parameter. And these results compared and analyzed simulation values with examination value. The simulation program for characteristic analysis used SUPREM IV for processing, Matlab for modeling by mathematics, and SPICE for electric characteristic of devices. Input parameter for simulation characteristics is like condition of device process sequence, these electric characteristic of I$_{D}$-V$_{D}$, I$_{D}$-V$_{G}$, variations of grain size. The Gate oxide thickness of poly silicon are showed similar results between real device characteristics and simulation characteristics.ristics.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.1037-1041
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• 1996

Input-output linearization technique in nonlinear control does not guarantee the robustness in the presence of parameter uncertainty or unmodeled dynamics, etc. However, it has been used as an important preliminary step in achieving additional control objectives, for instance, robustness to parameter uncertainty and disturbance attenuation. An indirect adaptive control scheme based on input-output linearization is proposed in this paper. The scheme consists of a Hopfield network for process parameter identification and an adaptive sliding mode controller based on input-output linearization, which steers the system response into a desired configuration. A numerical example is presented for the trajectory tracking of uncertain nonlinear dynamic systems with slowly time-varying parameters.

• The Journal of Korea Robotics Society
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• v.17 no.3
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• pp.347-352
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• 2022

The paper presents how to update impedance control parameters for dual-arm manipulators using EMG signals and motions of the operator. Since the hand motions of the dual-arm are modeled to be the mass-spring-damper system in this paper, the impedance parameter update method is an important issue to reflect the operator's force. However, task space inertia to be used as the mass parameter goes to infinity if the manipulator approaches a kinematic singularity. To alleviate this issue, the impedance (stiffness and damping) parameters are divided with a diagonal element of the task space inertia. Also, the stiffness and damping matrices are updated using the normalized EMG signals captured from the operator's forearm. Through this process, the motion of the dual-arm manipulator is more stabilized even though it approaches the kinematic singularity.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.5B no.4
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• pp.350-357
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• 2005

This paper presents a mechanical sensorless vector-controlled system with parameter identification by the aid of image processor. Based on the flux observer and the model reference adaptive system method, the proposed sensorless system includes rotor speed estimation and stator resistance identification using flux errors. Since the mathematical model of this system is constructed in a synchronously rotating reference frame, a linear model is easily derived for analyzing the system stability, including motor operating state and parameter variations. Because it is difficult to identify rotor resistance simultaneously while estimating rotor speed, a low-accuracy image processor is used to measure the mechanical axis position for calculating the rotor speed at a steady-state operation. The rotor resistance is identified by the error between the estimated speed using the estimated flux and the calculated speed using the image processor. Finally, the validity of this proposed system has been proven through experimentation.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.901-906
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• 1989

A robust stability problem for time delay systems is discussed by using a property of Lyapunov type operator equation. We propose a method to check the robust stability against the parameter perturbations occurring in both lumped parameter part and distributed delay element.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.10
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• pp.1075-1085
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• 1990

This paper presents a new method for the optimal control of the distributed parameter systems by a decentralized computational procedure. Approximate lumped parameter models are derived by using the Galerkin method employing the Legendre polynomials as the basis functions. The distributed parameter systems, however, are transformed into the large scale lumped parameter models. And thus, the decentralized control scheme is introduced to determine the optimal control inputs for the obtained lumped parameter models. In addition, an approach to block pulse functions is applied to solve the optimal control problems of the obtained lumped parameter models. The proposed method is simple and efficient in computation for the optimal control of distributed paramter systems. Illustrative examples given to demonstrate the validity of the presently proposed method.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.623-626
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• 1991

Crucial to the success of the vector control scheme without speed sensor is up to computing instantaneous position of the rotor flux. In tracing this flux depending on the machine parameter, variations of those factor lead to the non-linear charlcteristic between I/O value and decrease overall efficiency of the vector control scheme. This paper, using recursive least square method estimating instantaneous value of the machine speed and parameter from the shift of current and voltage, proposes an algorithm for compensating the I/O error of the scheme.

• Journal of international Conference on Electrical Machines and Systems
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• v.2 no.2
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• pp.184-189
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• 2013

This paper proposes a method for improving the performance of a position sensorless control system for a slotless surface permanent magnet synchronous motor (SPMSM) in a very low-speed region. In position sensorless control based on a motor model, accurate motor parameters are required because parameter errors would affect position estimation accuracy. Therefore, online parameter identification is applied in the proposed system. The error between the reference voltage and the voltage applied to the motor is also affect position estimation accuracy and stability, thus it is compensated to ensure accuracy and stability of the sensorless control system. In this study, two voltage error compensation methods are used, and the effects of the compensation methods are discussed. The performance of the proposed sensorless control method is evaluated by experimental results.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2252-2254
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• 2001

This paper proposes a algebraic parameter determination of MRAC (Model Reference Adaptive Control) controller using block Pulse functions and block Pulse function's differential operation. Generally, adaption is performed by solving differential equations which describe adaptive low for updating controller parameter. The proposes algorithm transforms differential equations into algebraic equation, which can be solved much more easily in a recursive manner. We believe that proposes methods are very attractive and proper for parameter estimation of MRAC controller on account of its simplicity and computational convergence.