• Journal of Institute of Control, Robotics and Systems
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• v.22 no.3
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• pp.177-185
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• 2016

This paper presents a method to design a controller for active suspension with 1-DOF decoupled models. Three 1-DOF decoupled models describing vertical, roll and pitch motions are used to design a controller in order to generate a vertical force, roll and pitch moments, respectively. These control inputs are converted into active suspension forces with geometric relationship. To design a controller, a sliding mode control is adopted. Frequency domain analysis and simulation on vehicle simulation software, CarSim$^{(R)}$, show that the proposed method is effective for ride comfort.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.24 no.1
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• pp.39-78
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• 2020

In this paper, we propose a decoupled local discontinuous Galerkin method for solving the Klein-Gordon-Schrödinger (KGS) equations. The KGS equations is a model of the Yukawa interaction of complex scalar nucleons and real scalar mesons. The advantage of our scheme is that the computation of the nucleon and meson field is fully decoupled, so that it is especially suitable for parallel computing. We present the conservation property of our fully discrete scheme, including the energy and Hamiltonian conservation, and establish the optimal error estimate.

• Proceedings of the KIEE Conference
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• 1988.11a
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• pp.135-139
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• 1988

This paper presents a new algorithm using power flow solution which is given by the polar form Newton-Raphson method in a transient stability analysis. The computation time to solve network equations can be much saved by a decoupled power flow method. In addition, the time is much saved in performing a approximate stability analysis by linearizing the differential equations and using a voltage and angle sensitivity matrix given in network equations.

• Structural Engineering and Mechanics
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• v.21 no.4
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• pp.423-435
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• 2005

A modal approach is proposed for dynamic analysis of concrete arch dam-reservoir systems in frequency domain. The technique relies on mode shapes extracted by considering the symmetric parts of total mass and stiffness matrices. Based on this method, a previously developed program is modified, and the response of Morrow Point arch dam is studied for various conditions. The method is proved to be very effective and it is an extremely convenient modal technique for dynamic analysis of concrete arch dams.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.10
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• pp.1683-1693
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• 1997

In this paper, a new nonlinear dynamic model is derived for a 2-dimensional overhead crane based on a new definition of 2-degree-of-freedom swing angle, and a new anti-swing control law is proposed for the crane. The dynamic model and control law take simultaneous travel and traverse motions of the crane into consideration. The model is first linearized for small motions of the crane load about the vertical stable equilibrium. Then the model becomes decoupled and symmetric with respect to the travel and traverse axes of the crane. From this result, a decoupled anti-swing control law is proposed based on the linearized model via the loop shaping and root locus methods. This decoupled method guarantees not only fast damping of load-swing but also zero steady state position error with optimal transient response for the 2-dimensional motion of the crane. Finally, the proposed control method is evaluated by controlling the simultaneous travel and traverse motions of a 2-dimensional prototype overhead crane. The effectiveness of the proposed control method is then proven by the experimental results.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.10a
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• pp.209-216
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• 1999

In tunneling and road cuts by blasting, it is of the utmost importance that the remaining rock is of high quality in order to avoid rockfall, rockslides and excessive maintenance work. Therefore, numerous blasting techniques which make use of decoupled charge or shock wave superposition effect have been used to control overbrake. In this paper. some approximate method for the determination of blast load according to the charge condition was introduced at first and, instrumented tests were conducted in small scale transparent material to investigate the shape and amplitude of blast load around the bore hole. Compare to the fully coupled charge, low amplitude of blast load around the bore hole was observed in the decoupled charge and explosion gas pressure was important in the shape of blast load. Therefore, quasi-static behaviour of the crack pattern was shown due to low loading rate.

• Structural Engineering and Mechanics
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• v.65 no.1
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• pp.69-79
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• 2018

This paper is devoted to two new techniques for free vibration analysis of concrete arch dam-reservoir systems. The proposed schemes are quadratic ideal-coupled eigen-problems, which can solve the originally non-symmetric eigen-problem of the system. To find the natural frequencies and mode shapes, a new special-purpose eigen-value solution routine is developed. Moreover, the accuracy of the proposed approach is thoroughly assessed, and it is confirmed that the new scheme is very accurate under all practical conditions. It is also concluded that both decoupled and ideal-coupled strategy proposed in the previous works can be considered as special cases of the current more general procedure.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.7
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• pp.824-831
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• 1999

This paper presents new methods to resolve the important limits in the decoupled UPFC model for power flow, by which conventional power flow program can be performed with addition of two buses per one UPFC. In order to operate UPFC to the desired value, the series voltage and shunt current of UPFC should be computed. So a method of calculating these by simple equations after power flow is derived. However, the calculated magnitude of series voltage and/or shunt current of UPFC may not be allowed because of the UPFC limit \ulcorner to the ratings of inverters. In this case, the active power and the reactive power (or the voltage magnitude) of UPFC buses should be revised to resolve the limit. This paper proposes the Newton Raphson method to resolve these limits. Particularly, when resolving the series voltage magnitude, three strategies are proposed according to the priority of the active power and the reactive power (or the voltage magnitude).

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1260-1263
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• 2000

Vector control of a single phase induction machine(SPIM) is usually employed by mechanical methods than electrical ones. The disadvantage of a SPIM has large noise at the starting. Using auxiliary winding which is only utilized for starting, the SPIM can be controlled with the vector control method. Regarding a auxiliary winding one phase, the SPIM is analyzed by the unsymmetrical two phase motor and phase transformation is unnecessary such as three phase IM. Including a auxiliary winding, SPIM is modeled by mathematical getting by component of turns ratio with main to auxiliary winding. It will be take with complicated resultant formula, by comparison to symmetrical three phase TM. For using the vector control theory, it must be decoupled of rotor flux and torque component. stator current is controlled and decoupled. This paper presents a variable-speed control system of SPIM, which to decoupled with flux and torque component and to use machine equivalent circuit referred to rotor, conventionally three phase IM by similar method.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.27 no.4
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• pp.272-280
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• 2023

We study the numerical analysis for the Cahn-Hilliard (CH) equation using the decoupled projection (DP) method. The CH equation is a fourth order nonlinear partial differential equation that is hard to solve. Therefore, various of numerical schemes have been proposed to solve the CH equation. To verify the relation of each existing scheme for the CH equation, we consider the DP method for linear convex splitting schemes. We present the numerical experiments to demonstrate our analysis. Throughout this study, it is expected to construct a novel numerical scheme using the relation with existing numerical schemes.