• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 하계종합학술대회논문집
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• pp.243-246
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• 1998

A predictive controller is designed based upon stochastic methods for compensation of network time delay which caused by the spatial separation between controllers and actuators. Current commands are generated by using time varying probability functions which can be defined according to the values of previous control inputs and actual outputs. To demonstrate the effect of this control methodology, simulation experiments are performed. The results show that even an unstabilized system by a long time delay can be stabilized with this predictive controller.

• East Asian mathematical journal
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• 제37권5호
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• pp.619-626
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• 2021

In [1, 2], we studied the string-like system with time-varying delay. Unlike the string system, the plate system must consider both longitudinal and transverse strains. First, we consider the physical phenomenon of an axially moving plate concerning kinetic energy, potential energy, and work dones. By the energy conservation law in physics, we have a nonlinear plate-like system with internal time delay.

• 제어로봇시스템학회논문지
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• 제18권5호
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• pp.401-406
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• 2012

This paper considers multi-agent systems with interval time-varying delays and switching interconnection topology. By construction of a suitable Lyapunov-Krasovskii's functional, new delay-dependent consensus control conditions for the systems are established in terms of LMIs (Linear Matrix Inequalities) which can be easily solved by various effective optimization algorithms. One numerical example is given to illustrate the effectiveness of the proposed methods.

• 전기학회논문지
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• 제60권11호
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• pp.2119-2130
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• 2011

This paper proposes new delay-dependent robust stability criteria for neural networks with time-varying delays. By construction of a suitable Lyapunov-Krasovskii's (L-K) functional and use of Finsler's lemma, new stability criteria for the networks are established in terms of linear matrix inequalities (LMIs) which can be easily solved by various effective optimization algorithms. Two numerical examples are given to illustrate the effectiveness of the proposed methods.

• 전기학회논문지
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• 제60권11호
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• pp.2103-2108
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• 2011

In this paper, the problem of passivity analysis for neural networks with time-varying delays and norm-bounded parameter uncertainties is considered. By constructing a new augmented Lyapunov functional, a new delay-dependent passivity criterion for the network is established in terms of LMIs (linear matrix inequalities) which can be easily solved by various convex optimization algorithms. Two numerical example are included to show the effectiveness of proposed criterion.

• 전기학회논문지
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• 제58권9호
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• pp.1809-1814
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• 2009

In this paper, the problem of stability analysis for neural networks with discrete and distributed time-varying delays is considered. By constructing a new Lyapunov functional, a new delay-dependent stability criterion for the network is established in terms of LMIs (linear matrix inequalities) which can be easily solved by various convex optimization algorithms. Two numerical example are included to show the effectiveness of proposed criterion.

• 전기학회논문지
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• 제66권1호
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• pp.171-178
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• 2017

This paper studies the state estimation problem for static neural networks with time-varying delay. Unlike other studies, the controller scheme, which involves time-varying sampling and uncertainties, is first employed to design the state estimator for delayed static neural networks. Based on Lyapunov functional approach and linear matrix inequality technique, the non-fragile sampled-data estimator is designed such that the resulting estimation error system is globally asymptotically stable with $H_{\infty}$ performance. Finally, the effectiveness of the developed results is demonstrated by a numerical example.

• 전기학회논문지
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• 제62권5호
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• pp.679-687
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• 2013

This paper proposes a new condition about delay-dependent robust $H_{\infty}$ control of uncertain linear systems with time-varying delay and randomly occurring disturbances. The norm bounded uncertainties are subjected to the system matrices. Based on Lyapunov stability theory, a sufficient condition for designing a controller gain such that the closed-loop systems are asymptotically stable with $H_{\infty}$ disturbance level ${\gamma}$ is formulated in terms of linear matrix inequalities (LMIs). Finally, two numerical examples are included to show the effectiveness of the presented method.

• 한국항행학회논문지
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• 제25권6호
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• pp.551-556
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• 2021

본 논문에서는 시변 지연 시간이 있는 선형 구간 이산 시스템에 비구조화된 불확실성이 존재하는 경우에 대하여 안정조건을 다룬다. 이산 시스템의 시스템 행렬들이 구간행렬의 형태로 주어지는 구간시스템에 대하여, 지연 시간이 일정 구간 범위 안에서 시변으로 변동되고, 비선형성을 포함한 불확실성이 그 크기만이 주어지는 비구조화된 불확실성의 형태로 존재하는 시스템의 안정성 조건을 제안한다. 안정조건의 유도는 기존의 리아프노프 방정식의 상한 해를 이용한 방법과는 다르게 리아프노프 안정 조건을 기반으로 이루어지며, 간단한 부등식의 형태로 표현되어 안정성 판단에 편리하게 적용될 수 있는 장점을 갖는다. 또한, 제안된 안정조건은 기존에 발표된 다양한 선형 이산 시스템의 안정조건들을 포함하는 매우 포괄적이고 강력한 것으로, 시변 지연시간 변동 크기, 불확실성의 크기와 구간행렬의 범위를 모두 조건식에 포함하게 된다. 새로운 조건의 우수함은 유도과정에서 증명되어지며 수치예제를 통하여 제안된 조건의 효용성과 우수성을 검증한다.

• ETRI Journal
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• 제34권2호
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• pp.210-215
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• 2012

In this paper, a group delay time controller (GDTC) is proposed based on a reflection topology employing a parallel resonator as the reflection termination. The design equations of the proposed GDTC have been derived and validated by simulation and experimental results. The group delay time can be varied by varying the capacitance and inductance at an operating frequency. To show the validity of the proposed circuit, an experiment was performed for a wideband code division multiple access downlink band operating at 2.11 GHz to 2.17 GHz. According to the experiment, a group delay time variation of $3{\pm}0.17$ ns over bandwidth of 60 MHz with excellent flatness is obtained.