• 제어로봇시스템학회논문지
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• 제17권3호
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• pp.241-247
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• 2011

This paper is intended to improve efficiency of two-phase BLDC motor using analytical and statistical methods, and then the stability of the starting for the designed model is investigated. The characteristics of the motor according to magnetization directions of permanent magnet are analyzed through the analytical method, and design variables that affect the efficiency are selected. Preliminary optimal design is performed using the analytical method with the design variable. The RSM (Response Surface Method) based on the FEA (Finite Element Analysis) is applied to complement errors of the analytical method. As a result, the optimal design is determined. Finally, the stability of the starting for the optimal designed model is evaluated by analyzing cogging torque, and it is verified through the FEA.

• East Asian mathematical journal
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• 제34권5호
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• pp.683-691
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• 2018

We consider an optimal control problem for an impulsive stage-structured model involving ordinary differential equations with impulsive values of initial conditions in the next year. The main goal is to maximize a profit of the catch of Pacific cod in the South Korea through optimal harvest strategy as a control of adult cod. We established necessary conditions for the optimal harvest control using idea of Pontryagin's maximum principle. The optimal harvest strategy is to numerically solve the equation by using an iterative method with the Runge-Kutta method. Finally, we compare a monthly average of fishing mortality of Pacific cod from 2013 to 2017 with monthly fishing mortality for result obtained optimal harvest strategy.

• 도시과학
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• 제7권1호
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• pp.55-61
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• 2018

Long bridges, such as suspension bridges and diagonal bridges, are complex phenomena that show different behaviors depending on the shape and rigidity of the cross sections, such as wind vibrations and liquid vibrations from earthquakes in liquid storage containers. This is called the lower skirt on the lower side of the bridge, and the installation of lower skirt is effective for release and vortex vibrations caused by rapid winds, and that increases the stability of the wind resistance of the bridge. Optimal shape and installation of the lower skirt is also essential to make maximum wind speed effect of the lower skirt. Therefore, this study proposes a numerical analysis method to control the vibration of a bridge by calculating the optimal installation angle of an optimal lower skirt according to the optimal control theory and this study evaluates the impact on the optimal control system by minimizing the dominance equation with an evaluation function,which is an indicator for evaluating the optimal control theory state.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅲ
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• pp.1267-1270
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• 2003

In this paper, we propose a optimal design method of the LVQ network. The proposed method determines the initial reference vectors and optimal network structure using the winning expectation of output neurons of SOM. In order to verify the effectiveness of the proposed method, we performed experiments on the Fisher's IRIS data. The experimental results showed that the proposed method improves considerably on the performance of the conventional LVQ networks.

• Journal of applied mathematics & informatics
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• 제6권2호
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• pp.513-522
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• 1999

In this paper we present a collocation method based on biquintic splines for a fourth order elliptic problems. To have a better accuracy we formulate the standard collocation method by an appro-priate perturbation on the original differential equations that leads to an optimal approximating scheme. As a result computational results confirm that this method is optimal.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.276-280
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• 1992

In the paper, an optimal tuning algorithm is presented to automatically improve the performance of a hybrid controller, using the simplified reasoning method and the proposed complex method. The method estimates automatically the optimal values of the parameters of a hybrid controller, according to the change rate and limitation condition of output, The controller is applied to plants with time-delay. Then, computer simulations are conducted at step input and the performances are evaluated in the ITAE.

• Communications for Statistical Applications and Methods
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• 제7권1호
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• pp.257-268
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• 2000

As one of indirect ways to get an optimal answer for sensitive questions both lower and upper values are sometimes asked and collected. In this paper a statistical method is proposed to analyze this kind of data using graphics. This method could define each sample median and estimate an optimal value between lower and upper bounds. In particular we find that this method has similar explanations of an equilibrium price with demand and supply functions in Economics.

• Communications for Statistical Applications and Methods
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• 제6권1호
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• pp.207-220
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• 1999

In this paper, some of the issue about a group sequential method are considered in the Bayesian context. The continuous time optimal stopping boundary can be used to approximate the optimal stopping boundary for group sequential designs. The exact stopping boundary for group sequential design is obtained by using the backward induction method and is compared with the continuous optimal stopping boundary and the corrected continuous stopping boundary.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.62.1-62
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• 2001

This paper suggests an inverse optimal PID control design method for the trajectory tracking case of mechanical systems. Also, simple coarse/fine performance tuning laws are suggested based on the analysis for performance limitation of inverse optimal PID controller. Experimental results for a robot manipulator show the validity of our analysis for the performance tuning methods.

• 대한안전경영과학회지
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• 제2권2호
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• pp.29-40
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• 2000

In this paper, under JIT kanban system designed by Moeeni, each performance measures (service level, inventory level) identify the robust optimal level at a uncertain environment, and when there are multiple performance characteristics, it propose the optimal design-method and the optimal level decision-method, which consider multiple performance characteristics.