• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.485-488
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• 2000

In this paper dynamic analyses and control design of a step-down switched-capacitor dc-dc converter are presented. Open-loop dynamics of the converter are analyzed using the stage-space averaging technique. A systmatic control design method that offers excellent closed-loop performance for the converter is proposed, The analysis results and dynamic performance of the converter are verified using 18 W experimental converter that delivers a 5V/3.5V output from a 11-16V input source.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.513-517
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• 1995

In this paper, a relation of matrix Q in cost function to distances between the closed-loop and open-loop poles of a multi input controllable systems is studied. Futhmore, the state feedback gain with exact desired eigenvalues in the LQR is computed. The proposed scheme is applied to designing automotive active suspension control system for a half-car model and its performance is compared with the existing LQR control system design methodology.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.63.4-63
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• 2002

$\textbullet$ Closed System Identification for inherently unstable systems $\textbullet$ Application of Observer/controller Identification (OCID) algorithm to those systems $\textbullet$ An open-loop system model with corresponding controller and observer gains are identified using OCID $\textbullet$ Experimental example of the OCID algorithm for an inverted pendulum system operating in closed-loop $\textbullet$ Modal analysis and time response to the added distrubance are presented to evaluate the performance of the OCID algorithm.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.577-582
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• 1989

This is a study of the translational end-point control of a single link flexible arm-with a tip mass. The beam is mounted on a translational mechanism driven by the ball screw, whose rotation is controlled by DC servomotor. The problem of shifting the end-point from its initial position to the commanded position is studied analytically both for the open-loop control subjected to some path functions and for the closed-loop control using the feedback of the tip information.

• 제어로봇시스템학회:학술대회논문집
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• 1986.10a
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• pp.298-303
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• 1986

A robust and efficient dynamic control algorithm for the position control of robotic manipulators is proposed. This algorithm consists of an open loop control and a closed loop control. The former may have a larger sampling time than the latter. The robustness and efficiency of this algorithm is demonstrated by the simulation about position control of a three-link manipulator with payload and parameter uncertainty.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.189-193
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• 1996

Piezoelectric actuator is widely used in precision positioning applications due to its excellent positioning resolution. However, serious hysteresis nonlinearity of the actuator deteriorates its open loop positioning capability. Generally, a nonlinear hysteresis model is used in feedforward loop to improve positioning accuracy. In this study, however, a simple lead compensator is proposed as a substitution for a complex nonlinear hysteresis model and tested through experiments for precision position control.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1984.10a
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• pp.43-47
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• 1984

This paper describes the mean time delay and its variance before transition from search to lock mode by means of signal flow graph and its transfer function. A relation between hit probability and search stage number is presented with the comparison of the open loop and closed loop. From these results optimum transition probability which we must hold can be obtained.

• 전기의세계
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• v.31 no.4
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• pp.296-302
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• 1982

The computer algorithm and program are developed to obtain the Luenberger Canonical form and the transform matrices for linear time invariant multivariable control systems. The model controller of an eigth order system, which assigns the modes of the multivariable control systems and closed-loop matrices are computed numerically by the developed programs. It is shown that the computed results coincide with the Luenberger's and Kalman's method. The gain of the model controller has varied from 10$^{-3}$ to 10$^{5}$ by the modes assignment of the open-loop system.

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.93.2-93.2
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• 2005

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.5
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• pp.43-50
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• 2018

The temperature of underground water generally remains constant regardless of the season. therefore, it is possible to get plenty of energy if we use characteristics of underground water for both cooling and heating. This study evaluates efficiency of real size coaxial and U-tube type complex geothermal system which is combined with underground water well. This study also evaluates relative efficiency/adaptability through comparison with existing geothermal systems(vertical closed loop system, open loop system(SCW)). The heat exchange capacity of complex geothermal system according to temperature difference between circulating water and underground water shows very high significance by increasing proportionally. The temperature change of underground water according to injection energy, shows very high linear growth aspect as injection thermal volume heightens. As a result of evaluation of heat exchange volume between complex geothermal system and comparative geothermal system, coaxial type has 26.1 times greater efficiency than comparative vertical closed type and 2.8 times greater efficiency than SCW type. U-tube type has 26.5 tims greater efficiency than comparative vertical closed type and 2.8 times greater than SCW type as well. This means complex geothermal system has extremely outstanding performance.