• Korean Journal of Mathematics
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• v.22 no.1
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• pp.123-131
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• 2014

The purpose of this paper is to study the perturbation analysis of the matrix equation $X=I-A^*X^{-1}A+B^*X^{-1}B$. Based on the matrix differentiation, we give a precise perturbation bound for the positive definite solution. A numerical example is presented to illustrate the shrpness of the perturbation bound.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.12
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• pp.2202-2205
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• 2011

Demand side management is used to maintain the reliability of power systems and to increase the economic benefits by avoiding power plant construction. This paper presents a systematic method to calculate the quantity of seasonal demand side management using time series. A numerical example is presented to calculate the quantity of demand side management in winter season using time series.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.101-104
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• 1997

In this paper, we deal with a quadratic stabilization by $H^{\infty}$ output feedback controllers with adjustable parameters. The designed controller contains a contractive time-varying gain which can be used to adjust the responses of the resulting closed-loop system. The free parameter expressed as time-varying gain is chosen so that a Lyapunov function of the closed-loop system descends as fast as possible. A numerical example is given to show the validity of proposed method..

• International Journal of Control, Automation, and Systems
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• v.5 no.6
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• pp.712-717
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• 2007

This paper is concerned with the problem of state feedback control of continuous-time nonlinear Markovian jump systems, which are represented by Takagi-Sugeno fuzzy models. A new method for designing state feedback stabilizing controllers is presented in terms of solvability of a set of linear matrix inequalities (LMIs), and it is shown that the new design method provides better or at least the same results of the existing method in the literature. Finally, a numerical example is given to illustrate the effectiveness of the proposed method.

• Journal of the Chungcheong Mathematical Society
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• v.21 no.3
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• pp.413-426
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• 2008

An asymptotic solution of a fourth order critically damped nonlinear differential system has been found by means of extended Krylov-Bogoliubov-Mitropolskii (KBM) method. The solutions obtained by this method agree with those obtained by numerical method. The method is illustrated by an example.

• Journal of the Korean Mathematical Society
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• v.34 no.4
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• pp.841-857
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• 1997

We present analysis and some computational methods for boundary optimal and feedback control problems for Navier-Stokes equations. We use one example to illustrate our methodology and ideas which are applicable to general control problems for Navier-Stokes equations. First, we discuss the existence of optimal solutions and derive an optimality system of equations from which an optimal solution may be computed. Then we present a gradient type iterative method. Finally, we present some numerical results.

• Journal of Korean Institute of Industrial Engineers
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• v.20 no.3
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• pp.105-116
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• 1994

This paper presents an inventory model with partial backorders for the situation in which demand is deterministic, lead time follows normal distribution and back order ratio during the stockout period varies in proportion to the length of backorder period In this situations, an objective function is formulated to minimize a time-proportional backorder cast and a fixed penalty cost per unit lost. And then the procedure of iterative solution method for the model is developed to find optimal reorder paint and order quantity and a numerical example to illustrate the proposed method is presented.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.4
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• pp.788-792
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• 2010

The problem of delay-dependent and parameter-dependent robust stability condition for discrete-time uncertain singular systems with polytopic uncertainty and interval time-varying delay is considered. A new robust stability condition based on parameter-dependent Lyapunov function is derived in terms of LMI (linear matrix inequality). Moreover, the proposed robust stability condition is a general condition for both singular and non-singular systems. A numerical example is presented to demonstrate the effectiveness of the proposed method.

• Journal of Korean Institute of Industrial Engineers
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• v.11 no.1
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• pp.11-19
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• 1985

This paper analyzes the multi-item order-level system with shortages allowance and storage limitation. Up to now, we have used the classical optimization theory to analyze this system. But the theory is generally not suitable for computational purposes. Therefore, this paper designes a new method to be able to apply the quadratic programming to the multi-item order-level system with storage limitation. A numerical example is also presented.

• Journal of Korean Institute of Industrial Engineers
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• v.11 no.1
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• pp.41-49
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• 1985

This paper studies the two supplier inventory system in which order-level inventory policy with constant leadtimes is adopted. An optimal ordering policy to achieve the expected minimum total inventory cost is found by utilizing the concepts of the equivalence relation. Sensitivity analysis of the system parameters, the replenishment cost and the unit price, is done through a numerical example.