Sang-Choel Lee

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This paper is concerned with the stability and stabilization problems for discrete-time systems with interval time-varying delays. By construction of an augmented Lyapunov–Krasovskii functional and utilization of zero equalities, improved delay-dependent criteria for asymptotic stability of the systems are derived in terms of linear matrix inequalities(More)
In this Letter, we propose new criteria for asymptotic stability of Lur’e systems with sector and slope restrictions. The criteria are expressed in terms of linear matrix inequality which has full block scaling matrix. By interpreting the criteria in the frequency domain using KYP lemma, the less conservativeness of the proposed analysis method is(More)
This article deals with the robust H1 filtering problem for neutral delay differential systems with parametric uncertainties. A linear matrix inequality (LMI) approach is proposed to design the robust H1 filter such that the filtering system remains asymptotically stable and the bound ofH1 norm is minimized. The Lyapunov stability theory is used for(More)
In this paper, we consider the problem of finding the stability region in state space for uncertain linear systems with input saturation. For stability analysis, two Lyapunov functions are chosen. One is for the linear region and the other is for the saturated region. Piecewise Lyapunov functions are obtained by solving successive linear matrix(More)
1 School of Electrical Engineering, Chungbuk National University, 52 Naesudong-ro, Heungduk-gu, Cheongju 361-763, Republic of Korea. 2 Department of Electrical Engineering, Yeungnam University, 214-1 Dae-dong, Kyongsan 712-749, Republic of Korea. 3 School of Electronics Engineering, Daegu University, Gyungsan 712-714, Republic of Korea. 4 Department of(More)
The general dilemma faced in a conventional linear proportional–integral (PI) controller is to achieve the best transient performance (i.e. fast rise time and low overshoot level) at the same time. However, fast response is usually accompanied by high overshoot level. On the other hand, very stable control without overshoot is usually achieved at the(More)
and Applied Analysis 3 Theneuron activation functions,g p (y p (⋅)) (p = 1, . . . , n), are assumed to be nondecreasing, bounded, and globally Lipschitz; that is, l − p ≤ g p (ξ p ) − g p (ξ q ) ξ p − ξ q ≤ l + p , ∀ξ p , ξ q ∈ R, ξ p ̸ = ξ q , (5) where l− p and l+ p are constant values. For simplicity, in stability analysis of the network (1), the(More)
and Applied Analysis 3 2. Problem Statements Consider the following discrete-time neural networks with interval time-varying delays: y k 1 Ay k W0g ( y k ) W1g ( y k − h k ) b, 2.1 where n denotes the number of neurons in a neural network, y k y1 k , . . . , yn k T ∈ R is the neuron state vector, g k g1 k , . . . , gn k T ∈ R denotes the neuron activation(More)
In this paper, we propose a robust controller design method for discrete-time systems with sector-bounded nonlinearities and time-varying delay. Based on the Lyapunov theory, delaydependent stabilization criteria are obtained in terms of linear matrix inequalities (LMIs) by constructing the new Lyapunov-Krasovskii functional and using some inequalities. A(More)
This paper is concerned with the synchronization problem for complex dynamical networks with time-varying coupling delay and sampled-data. The sampling period considered here is assumed to be time-varying but bounded. A novel exponential synchronization condition is established based on the Gronwall's inequality, and an explicit expression for a set of(More)
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