• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.9
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• pp.64-75
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• 2007

Photovoltaic systems utilize the infinite clean energy of the sun, without creating any air pollution or noise and mechanical vibration. A PV system operates without the need of fuel, rotation surfaces, high temperatures or high pressures. It is therefore to do maintain and simple to install as well as having a long life cycle. The global market for PV systems continues to grow rapidly by 30[%] per year. This paper suggests a new design method for the PV system installation that will allow to the improvement of system efficiency. This method is in accordance with the loss parameter compensation method designed for the PV systems and investigated through simulation and practical experimentation. It was applied to an interconnected 10[kW] grid PV system and was demonstrated in the field. Features such as solar array, PCS, system efficiency, performance and stability were considered. Through the proposed optimal parameter design method, the features of the system were studied, and the 10[kW] PV system was demonstrated and analyzed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.506-510
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• 2004

A torque transmission system composed of several gears and couplings is flexible. In order to get an exact response of motor, the torsional vibration due to an unexpected change of motor speed must be suppressed. Therefore, it is very important that motor control suppress vibration. Various methods to control it including dual inertia system are proposed. Specially, the method of vibration suppression is that vibration can be suppressed to fee㏈ack the estimated torsion torque via the disturbance observer filter being of normal filter. The suitable Proportional controller and coefficient parameter can be designed using CDM and the torsional vibration also be suppressed, but it has a low degree of adaptability to disturbance. The PID controller can be designed easily, but makes the excessive overshoot and oscillation for system response in the early period. To resolve these problems, simple and practical PID controller with two degree of freedom is proposed recently that it ran improve performance of obeying the reference unconcerned in any disturbance by changing the proportional gain by two degree of freedom parameter. But it has also the defect that parameter a must be changed to obtain the ideal Proportional parameter. On this paper, we design the controller which automatically adjusts parameter u using fuzzy Algorithm to overcome such defects. Also, we compare the proposed method with established one and evaluate them to confirm performance of the designed controller.

• International Journal of Reliability and Applications
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• v.2 no.1
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• pp.37-48
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• 2001

This paper presents a new dynamic human reliability analysis method and its application for quantifying the human error probabilities in implementing management action. For comparisons of current HRA methods with the new method, the characteristics of THERP, HCR, and SLIM-MAUD, which are most frequency used method in PSAs, are discussed. The action associated with implementation of the cavity flooding during a station blackout sequence is considered for its application. This method is based on the concepts of the quantified correlation between the performance requirement and performance achievement. The MAAP 3.0B code and Latin Hypercube sampling technique are used to determine the uncertainty of the performance achievement parameter. Meanwhile, the value of the performance requirement parameter is obtained from interviews. Based on these stochastic obtained, human error probabilities are calculated with respect to the various means and variances of the things. It is shown that this method is very flexible in that it can be applied to any kind of the operator actions, including the actions associated with the implementation of accident management strategies.

• Journal of information and communication convergence engineering
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• v.5 no.2
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• pp.164-170
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• 2007

In this paper, the new method alternating with the method for forming the symmetrical distribution of power and local dispersion in high bit-rate WDM system with optical phase conjugator (OPC) is proposed. The proposed method is carried by finding out the optimal values of OPC position offset and fiber dispersion offset. It is assumed to be that NRZ-formatted 24-channels of 40 Gbps are simultaneously propagated in WDM system with non zero - dispersion shifted fiber (NZ-DSF) of 1,000 km. It is confirmed that the compensation extents of overall WDM channels are more improved by applying the induced optimal values into WDM system than those in WDM system with the conventional mid-span spectral inversion (MSSI) technique, and the searching procedure of the optimal values makes little difference of performance if the optimal value of one parameter related with another parameter. And, it is confirmed that the flexible design of WDM system with OPC is possible by effectiviely using by these optimal values. Thus, it is expected that the proposed method alternate with the forming method of the symmetrical distributions of power and local dispersion.

• Journal of Power Electronics
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• v.16 no.2
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• pp.598-609
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• 2016

The good control performance of permanent magnet linear synchronous motor (LSM) drive systems is difficult to achieve using linear controllers because of uncertainty effects, such as fictitious forces. A backstepping control system using adaptive modified recurrent Laguerre orthogonal polynomial neural network uncertainty observer (OPNNUO) is proposed to increase the robustness of LSM drive systems. First, a field-oriented mechanism is applied to formulate a dynamic equation for an LSM drive system. Second, a backstepping approach is proposed to control the motion of the LSM drive system. With the proposed backstepping control system, the mover position of the LSM drive achieves good transient control performance and robustness. As the LSM drive system is prone to nonlinear and time-varying uncertainties, an adaptive modified recurrent Laguerre OPNNUO is proposed to estimate lumped uncertainties and thereby enhance the robustness of the LSM drive system. The on-line parameter training methodology of the modified recurrent Laguerre OPNN is based on the Lyapunov stability theorem. Furthermore, two optimal learning rates of the modified recurrent Laguerre OPNN are derived to accelerate parameter convergence. Finally, the effectiveness of the proposed control system is verified by experimental results.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.7
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• pp.919-926
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• 2012

In order to control a LTI(Linear Time Invariant) system subjected to system noise and measurement noise, first of all, it is necessary to estimate the state of system with reliability. Kalman filtering technique has been widely used to estimate the state of the stochastic LTI system with stationary noise characteristics because of its estimation ability versus algorithm simplicity. However, it often fails to estimate the state of the LTI system of which system parameter uncertainty exists partly and/or input uncertainty exists. In this paper, a new estimation technique based on Kalman filter is suggested for stochastic LTI system under parameter uncertainty and/or input uncertainty. A fuzzy estimation algorithm against uncertainties is introduced so as to compensate the state estimate filtered by Kalman filter. In order to verify the state estimation performance of the suggested technique, several simulations are accomplished.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.104-108
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• 2002

In this study, the dynamic absorbing system for the shoulder-fired system with high-level-impact force has been investigated. for this purpose, firstly, mathematical model based on the short recoil system has been constructed. In order to design the dynamic absorbing system, parameter sensitivity analysis and parameter optimization process have been performed under constraints of moving displacement and transmitted force. In order to enhance the efficiency of energy dissipation, the stroke-dependent variable damping system has been analyzed. finally, the performance of the designed dynamic absorbing system has been evaluated by simulation with respect to the benchmark system.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.11a
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• pp.45-46
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• 2005

In this paper, a passive telemetry sensor system using Unscented Kalman Filter(UKF) is proposed. Specially, to show the effective tracking performance of the UKF, we compared with the tracking performance of Recursive Least Square Estimation (RLSE) using linearization.

• Journal of the Korean Institute of Telematics and Electronics
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• v.24 no.6
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• pp.956-960
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• 1987

This paper investigates the control problem which is specified by an uncertain linear system and a linear quadratic performance index. Only the size of parameter uncertainty is assumed to be given instead of its statistics. In addition, a mathing condition which constrains the system structure is assumed to be satisfied. The control law can be obtained by solving an LQ optimal control problem for a nominal system.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.48.2-48
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• 2001

This paper deals with robust integral tracking control problem based on Lyapunov method via FL(Feedback Linearization) in order to solve a reference tracking problem of nonlinear system with parameter uncertainties. To overcome a restrictive matching condition the uncertainties is characterized in a suitable form. The design procedure which combine FL and LMIs(Linear Matrix Inequalities) based on Lyapunov method to achieve the robust performance and stability is developed. Finally, the performance of proposed controller is demonstrated via simulation of a linear reference tracking problem in the MLS(Magnetic levitating System).