• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.663-665
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• 2004

Ethernet-based passive optical network(EPON) technology is being considered as a promising solution for next-generation broadband access network. It must have the property of high efficiency, low cost, and support quality of service(QoS). A major feature for this new architecture is the use of a shared transmission media between all connected optical network unit(ONU). Hence, medium access control(MAC) arbitration mechanisms are essential for the successful implementation of EPON. In this paper we propose a simple dynamic bandwidth allocation(DBA) algorithm that improves the performance of network and supports IP-based multimedia applications with the bursty data traffic. In addition, we introduce analytic models of proposed algorithms and prove the system based on our algorithm to be asymptotically stable. Simulation results show the new DBA algorithm provides high bandwidth efficiency and low queueing delay of ONU in EPON.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.11
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• pp.1142-1146
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• 2014

This paper addresses on a $H_{\infty}$ sampled-data stabilization of a Takagi-Sugeno (T-S) fuzzy system. The sampled-data stabilization problem is formulated as a discrete-time stabilization one via a direct discrete-time design approach. It is shown that the sampled-data fuzzy control system is asymptotically stable whenever its exactly discretized model is asymptotically stable. Based on an exact discrete-time model, sufficient design conditions are derived in the format of linear matrix inequalities (LMIs). An example is provided to illustrate the effectiveness of the proposed methodology.

• Journal of the Chungcheong Mathematical Society
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• v.30 no.1
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• pp.103-116
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• 2017

In this paper, we show that the solutions to perturbed differential system $$y^{\prime}=f(t,y)+{{\displaystyle\smashmargin{2}{\int\nolimits_{t_0}}^{t}}g(s,y(s),T_1y(s))ds+h(t,y(t),T_2y(t))$$ have asymptotic property by imposing conditions on the perturbed part ${\int_{t_0}^{t}}g(s,y(s),T_1y(s))ds,h(t,y(t),T_2y(t))$, and on the fundamental matrix of the unperturbed system y' = f(t, y).

• Journal of the Korean Mathematical Society
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• v.58 no.1
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• pp.45-67
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• 2021

In this paper, a mathematical dynamical system involving both deterministic (with or without delay) and stochastic "SIR" epidemic model with nonlinear incidence rate in a continuous reactor is considered. A profound qualitative analysis is given. It is proved that, for both deterministic models, if ��d > 1, then the endemic equilibrium is globally asymptotically stable. However, if ��d ≤ 1, then the disease-free equilibrium is globally asymptotically stable. Concerning the stochastic model, the Feller's test combined with the canonical probability method were used in order to conclude on the long-time dynamics of the stochastic model. The results improve and extend the results obtained for the deterministic model in its both forms. It is proved that if ��s > 1, the disease is stochastically permanent with full probability. However, if ��s ≤ 1, then the disease dies out with full probability. Finally, some numerical tests are done in order to validate the obtained results.

• Journal of applied mathematics & informatics
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• v.13 no.1_2
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• pp.217-222
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• 2003

In this paper, we consider the fuzzy differential equations (equation omitted) where F(t, x(t)) is a continuous fuzzy mapping on [0, $\infty$) ${\times}$ E$\^$n/. The purpose of this paper is to prove that the solution ${\Phi}$(t) of the fuzzy differential equations is equiasymptotically stable in the large and uniformly asymptotically stable in the large.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.3
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• pp.266-272
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• 2004

In this paper, an observer-based adaptive controller is proposed to control the longitudinal motion of vehicles. The standard gradient method will be used to estimate the vehicle parameters such as mass, time constant, etc. The nonlinear model between the driving force and the vehicle acceleration will be chosen to design the state observer for the vehicle velocity and acceleration. It will be shown that the proposed observer is exponentially stable, and that the adaptive controller proposed in this paper is stable by the Lyapunov function candidate. It will be proved that the errors of the relative distance, velocity and acceleration converge to zero asymptotically fast, and that the overall system is also asymptotically stable. The simulation results are presented to investigate the effectiveness of the proposed method.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.83.3-83
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• 2002

$\textbullet$ In this paper, a robust decentralized excitation control scheme is proposed $\textbullet$ We prove that the proposed control system is practically stable $\textbullet$ The origin is globally uniformly asymptotically stable in the absence of the disturbance $\textbullet$ If assumption is not satisfied, the proposed control system is still guarantees L2 stability $\textbullet$ Simulations for a three-machine power system demonstrates the effectiveness of the proposed scheme

• Kyungpook Mathematical Journal
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• v.47 no.1
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• pp.31-56
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• 2007

In this paper, we consider a delay differential equation model of two competing species with harvesting of the mature and immature members of each species. The time delay in the model represents the time from birth to maturity of that species, which appears in the adults recruitment terms. We study the dynamics of our model analytically and we present results on positivity and boundedness of the solution, conditions for the existence and globally asymptotically stable of equilibria, a threshold of harvesting, and the optimal harvesting of the mature populations of each species.

• Journal of Industrial Technology
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• v.10
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• pp.3-8
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• 1990

This paper presents a linear state feedback control approach to the stabilization of discrete-time uncertain systems with bounded uncertain parameters. The approach is based on the LQ(linear quadratic) regulator theory and Lyapunov's stability analysis. Asymptotically stable behavior is guaranteed in the presence of parameter uncertainties, and the upper bound of the performance index is determined.

• The Pure and Applied Mathematics
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• v.5 no.2
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• pp.143-147
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• 1998

We show that a real valued function $\phi$ defined by $\phi (\chi)$ = (equation omitted) is a Lyapunov function of compact asymptotically stable set M.