• Korean Journal of Mathematics
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• v.24 no.1
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• pp.1-13
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• 2016

This paper shows that the solutions to the perturbed functional dierential system $$y^{\prime}=f(t,y)+{\int_{t_0}^{t}}g(s,y(s),Ty(s))ds$$ have uniformly Lipschitz stability and asymptotic property. To sRhow these properties, we impose conditions on the perturbed part ${\int_{t_0}^{t}}g(s,y(s),Ty(s))ds$ and the fundamental matrix of the unperturbed system $y^{\prime}=f(t,y)$.

• Journal of the Chungcheong Mathematical Society
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• v.29 no.3
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• pp.429-442
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• 2016

In this paper we show that the solutions to the perturbed differential system $$y^{\prime}=f(t,y)+{\int}_{to}^{t}g(s,y(s),Ty(s))ds$$ have uniformly Lipschitz stability and asymptotic behavior by imposing conditions on the perturbed part $\int_{to}^{t}g(s,y(s),Ty(s))ds$ and the fundamental matrix of the unperturbed system y' = f(t, y).

• Journal of the Korean Home Economics Association
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• v.33 no.5
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• pp.187-196
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• 1995

This study was performed was performed to identify the predictability of maternal attitude from infant's temperament and mother's mental stability. It was focused on the comparison of the degree of predictability between infant's temperament and mother's mental stability. Data were collected from sixty-five mothers of infants. Mother's affective attitude was explained by both the maternal mental stability and the infant's temperament. After controlling the effect of mental stability, infant's temperament could explain the affective attitude. This result meant that infant's temperament showed the powerful effect on the maternal affective attitude. However, maternal controlling attitude was only explained by her mental stability but not by infant's temperament. This meant that infant's temperament could not explain mother's controlling behavior. However, interactive effect between infant's sex and temperament was found in the controlling attitude. Mothers showed more controlling attitude toward the difficult boys but not toward the difficult girls.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.10
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• pp.1387-1392
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• 2012

These days people use a lot of electric power, because industry advancement and a standard of living is elevated. So voltage stability analysis and control problems are very important in these days. U.S.A has already developed voltage stability analysis program, and use it on power transmission scheme such as generator overhaul, transmission line off and so on. So voltage stability analysis is more and more interested in Korea, too. In this paper, we introduce a standard theory of voltage stability analysis and real time voltage stability analysis program that use sPMU(Satellite Phasor Measurement Unit). And we also introduce the calculation result about voltage stability in Jeju power transmission system.

• Journal of the Korea Organic Resources Recycling Association
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• v.14 no.2
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• pp.63-70
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• 2006

The purpose of this study was to develop the stability index of landfill sites to assess it's degree of stability. In order to develop the stability index, field data including leachate qualities, Landfill gas (LFG) composition and element composition of wastes from 50 closed landfills were collected. Three parameters-BOD/CODcr among leachate quality parameters, $CH_4$ among landfill gases, and C/N ratio from wastes-were found to be the best parameters for measuring the stability of landfill sites. The trend line of these parameters were used to Also, $CH_4$ from landfill gases and C/N ratio from wastes were found to be the best parameters. The trend lines of these parameters were used to develop the stability index of landfill sites. The equation for the index was as following; $I_{LS}=S_L+S_G+S_W$ $S_L=-\{4.892+16.587{\cdot}ln[BOD/COD_{Cr]\}$ $S_G=53.872-12.782{\cdot}ln[CH_4]$ $S_W=79.382-20.013{\cdot}ln[C/N]$ (The maximum score for $S_L$, $S_G$, and $S_W$ was 33.3.) where, $I_{LS}$ : The stability index of the landfill $S_L$ : The stability score of the leachate $S_G$ : The stability score of the landfill gas $S_W$ : The stability score of the waste.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.95.1-95
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• 2001

This paper is concerned with a novel S-stability (stochastic-stability) concept in linear time-invariant stochastic systems, where a stochastic mode in dynamics depends on both the external disturbance and the inner-parameter variations. This leads to an EAG (eigenstructure assignment gaussian) problem; that is, the problem of associating S-eigenvalues (stochastic-eigenvalues), S-eigenvectors (stochastic-eigenvectors), and their PDFs (probability density functions) with the stochastic information of the systems with the required stochastic specifications. These results explicitly characterize how S-eigenvalues, S-eigenvectors and their PDFs in the complex plane may impose S-stability on stochastic systems.

• The Pure and Applied Mathematics
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• v.23 no.1
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• pp.1-12
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• 2016

This paper shows that the solutions to the perturbed differential system $y^{\prime}=f(t, y)+\int_{to}^{t}g(s,y(s),Ty(s))ds+h(t,y(t))$ have asymptotic property and uniform Lipschitz stability. To show these properties, we impose conditions on the perturbed part $\int_{to}^{t}g(s,y(s),Ty(s))ds+h(t,y(t))$, and on the fundamental matrix of the unperturbed system y' = f(t, y).

• 제어로봇시스템학회:학술대회논문집
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• 1987.10a
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• pp.827-831
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• 1987

The analysis of a certian example and simulations given in the previous sections show that the modified FKA is more stable than the standard FKA without loss of the performance of it. The general analysis of modified FKA's numerical stability is the open problem with more simulations in order to prove the stability of it.

• Journal of the Korean Institute of Intelligent Systems
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• v.7 no.3
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• pp.72-80
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• 1997

A new design method for Takagi-Sugeno (T-S in short) fuzzy controller which guarantees global asymptotic stability and satisfies a desired performance is proposed in this paper. The method uses LMI(Linear Matrix Inequality) approach to find the common symmetric positive definite matrix P and feedback fains K/sub i/, i= 1, 2,..., r, numerically. The LMIs for stability criterion which treats P and K'/sub i/s as matrix variables is derived from Wang et al.'s stability criterion. Wang et al.'s stability criterion is nonlinear MIs since P and K'/sub i/s are coupled together. The desired performance is represented as $ LMIs which place the closed-loop poles of $ local subsystems within the desired region in s-plane. By solving the stability LMIs and pole placement constraint LMIs simultaneously, the feedback gains K'/sub i/s which gurarntee global asymptotic stability and satisfy the desired performance are determined. The design method is verified by designing a T-S fuzzy controller for an inverted pendulum with a cart using the proposed method.

• Communications of the Korean Mathematical Society
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• v.18 no.1
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• pp.133-149
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• 2003

Local stability of steady states of an epidemic model is considered. An age structured S-I-R epidemic model with separable inter-cohort force of infection with external force is considered. Stability result for the nontrivial steady states is obtained.