• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1486-1491
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• 2005

In this paper, a robust H${\infty}$ stabilization problem to a uncertain fuzzy systems with time-varying delay via static output feedback is investigated. The Takagi-Sugeno (T-S) fuzzy model is employed to represent uncertain nonlinear systems with time-varying delayed state, which is a continuous-time or discrete-time system. Using a single Lyapunov function, the globally asymptotic stability and disturbance attenuation of the closed-loop fuzzy control system are discussed. Sufficient conditions for the existence of robust H${\infty}$controllers are given in terms of linear matrix inequalities.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.37 no.4
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• pp.1-10
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• 2000

This paper deals with an H$_{\infty}$ output feedback control problem for linear systems with commensurate time delay in both state and input variables. The proposed output feedback controller also has commensurate time delay terms in the controller state. The controller can be synthesized based on the solution of the linear matrix inequalities(LMI) which can be easily solved using the convex optimization method. In order to demonstrate the efficacy of the proposed method, numerical examples are presented.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.299-304
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• 1996

This paper studies the rational approximation of multiple input delay systems using the Hankel singular values and vectors, which are the soultion of a transcendental equation. Rational approximatants are obtained from output normal realizations which are constructed by the Hankel singular values and vectors. Consequently, it is shown that rational approximants by output normal realization preserve intrinsic properties of time delay systems than Pade approximants.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2005.04a
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• pp.149-152
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• 2005

In this paper, a robust $H\infty$ stabilization problem to a uncertain discrete-time fuzzy systems with time-varying delay via static output feedback is investigated. The Takagi -Sugeno (T-S) fuzzy model is employed to represent an uncertain nonlinear systems with time-varying delayed state. Using a single Lyapunov function, the globally asymptotic stability and disturbance attenuation of the closed-loop fuzzy control system are discussed. Sufficient conditions for the existence of robust $H\infty$ controllers are given in terms of linear matrix inequalities.

• Journal of Institute of Control, Robotics and Systems
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• v.4 no.2
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• pp.151-156
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• 1998

This paper presents an $H_{\infty)$ output feedback controller design method for linear systems with delayed state, delayed control input, and delayed masurement output. Using a Lyapunov functional, the stability for delayed systems is discussed independently of delays. Also, sufficient condition for the existence of $H_{\infty)$ controllers of any order is given in terms of three linear matrix inequalities(LMIs). Based on positive definite solutions of their LMIs, we briefly explain the way to construct $H_{\infty)$ controller, which stabilizes time-delay systems independently of delays and guarantees an $H_{\infty)$norm bound.

• 전자공학회논문지 IE
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• v.48 no.3
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• pp.1-9
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• 2011

In this paper, we develop an analytical expression for the propagation delay of submicrometer CMOS inverter using the triangle-shaped waveform of output current and two fitting parameters. Our model shows that simulation results are well in accordance with HSPICE results. Maximum simulation errors of total inverter delay and jitter are below 0.6% and 2.8%, respectively. Comparing with previous researches, the new model has better fittering characteristics in the range of low operating voltage. We also have fabricated the inverters with ten chains and estimated inverter delay and jitter characteristics. The results show that the values of delay and jitter in the fabricated samples come close to the values of those in the new model.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.11
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• pp.2828-2835
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• 1996

In this paper we propose a new shaping algorithm which can control the shaping delay and the output buffer size based on the leaky bucket counter with a threshold value. This paper assumes that input traffic of the proposed shaping algorithm is the worst case traffic tolerated by the continuous leaky bucket algorithm and claracterizes traffic patterns that can depart from our shaping algorithm. We also compare shaping delay and output buffer size of the proposed algorithm with the existing shaping algorithm without a threshold value. Our results show that the proposed shaping algorithm can easily manage the shaping delay and output buffer size than any other mechanism.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.16 no.6
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• pp.465-471
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• 2023

This paper proposes a comparator structure that improves the noise and output delay of a single-slope ADC(SS-ADC) used in CMOS Image Sensor (CIS). To improve the noise and delay characteristics of the output, a comparator structure using the miller effect is designed by inserting a capacitor between the output node of the first stage and the output node of the second stage of the comparator. The proposed comparator structure improves the noise, delay of the output, and layout area by using a small capacitor. The CDS counter used in the single slop ADC is designed using a T-filp flop and bitwise inversion circuit, which improves power consumption and speed. The single-slope ADC also performs dual CDS, which combines analog correlated double sampling (CDS) and digital CDS. By performing dual CDS, image quality is improved by reducing fixed pattern noise (FPN), reset noise, and ADC error. The single-slope ADC with the proposed comparator structure is designed in a 0.18-㎛ CMOS process.

• Proceedings of the KIEE Conference
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• 2005.05a
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• pp.87-89
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• 2005

This paper presents an optimal tuning method of the decentralized PI controller of the two-input, two-output(TITO) second order system with time-delay using LQR approach.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.886-891
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• 2003

This paper deals with designing a ground-based longitudinal landing controller which is robust to datalink time delays. Time delays occur because forward velocity measurements are downlinked and the controller output commands are uplinked. An $H_{\infty}$ controller was designed by using the input/output decomposition where time delay is modeled as a first-order system with Pade approximation. Linear simulations show that the system tracks well the predefined path and is robust to the variation of time delay.