• 제목/요약/키워드: Liu system

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백스테핑을 이용한 카오스 Liu 시스템의 제어 (Control and Tracking Chaotic Liu Systems via Backstepping Design)

  • 유성훈;현창호;박민용
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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    • pp.324-326
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    • 2006
  • This paper present backstepping control approach for controling chaotic Liu system. The proposed method is a systematic design approach and consists in a recursive procedure that interlaces the choice of a Lyapunov Function. Based on Lyapunov stability theory, control laws are derived. We used the same technique to enable stabilization of chaotic motion to a steady state as well as tracking of any desired trajectory to be achieved in a systematic way. Numerical solution are shown to verify the result.

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A UPS BASED ON A NEW SPWM GENERATOR

  • Liu, Shulin;Liu, Jian
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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    • pp.808-812
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    • 1998
  • A new SPWM control method for Uninterrupted Power System(UPS) is presented. A triangle waveform is used as the reference signal. The desired SPWM control signal can be obtained more easily with a group of comparators. The output AC voltage can be regulated by controlling the lower reference and the upper reference of the comparators according to the feedback voltage. Basic principle, an actual circuit and the experimental results on a 500W UPS for computer system is discussed as an example.

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Flexible Iterative Learning Control Based Expert System and Its Application

  • Zuojun, Liu;Zhihu, Liu;Linan, Zu;Peng, Yang
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제9권3호
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    • pp.185-190
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    • 2009
  • A scheme of expert system based on iterative learning control is proposed. Iterative learning control can obtain control experience from the historical data to build the knowledge base of expert system. Considering some uncertain factors, a flexible measure is adopted in iterative learning control (ILC). Simulation proves the feasibility and effect of the air conditioning control expert system based on flexible iterative learning control (F-ILC). Finally, a feedback compensation unit is incorporated against irregular heavy disturbance.

Generalized Stability Criterion for Multi-module Distributed DC System

  • Liu, Fangcheng;Liu, Jinjun;Zhang, Haodong;Xue, Danhong
    • Journal of Power Electronics
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    • 제14권1호
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    • pp.143-155
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    • 2014
  • The stability issues of a multi-module distributed DC power system without current-sharing loop are analyzed in this study. The physical understanding of the terminal characteristics of each sub-module is focused on. All the modules are divided into two groups based on the different terminal property types, namely, impedance (Z) and admittance (Y) types. The equivalent circuits of each group are established to analyze the stability issues, and the mathematical equations of the equivalent circuits are derived. A generalized criterion for multi-module distributed systems is proposed based on the stability criterion in a cascade system. The proposed criterion is independent of the power flow direction.

Design of online damage images detection system for large-aperture mirrors of high power laser facility based on wavefront coding technology

  • Fang, Wang;Qinxiao, Liu;Dongxia, Hu;Hongjie, Liu;Tianran, Zheng
    • Nuclear Engineering and Technology
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    • 제53권9호
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    • pp.2899-2908
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    • 2021
  • The laser transport system of the high power laser facility is mainly composed of large-aperture laser transport mirrors (TMs). Obtaining the high-resolution online damage images during the operation, which is of great significance for operating safely of the mirrors and the facility. Based on wavefront coding, pan-tilt scanning and image stitching technologies, an online laser-damage images detection system is designed, and it can achieve high-precision detection of surface characteristics of large-aperture laser transport mirrors. The preliminary simulation proves that the system can solve the depth of field matching problem caused by pan-tilt tilt imaging and achieve higher resolution.

COMMON FIXED POINT THEOREMS WITH APPLICATIONS TO THE SOLUTIONS OF FUNCTIONAL EQUATIONS ARISING IN DYNAMIC PROGRAMMING

  • Liu, Zeqing;Liu, Min;Kim, Hyeong-Kug;Kang, Shin-Min
    • 대한수학회논문집
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    • 제24권1호
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    • pp.67-83
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    • 2009
  • Several common fixed point theorems for a few contractive type mappings in complete metric spaces are established. As applications, the existence and uniqueness of common solutions for certain systems of functional equations arising in dynamic programming are discussed.

Exact Controllability for Fuzzy Differential Equations in Credibility Space

  • Lee, Bu Young;Youm, Hae Eun;Kim, Jeong Soon
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제14권2호
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    • pp.145-153
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    • 2014
  • With reasonable control selections on the space of functions, various application models can take the shape of a well-defined control system on mathematics. In the credibility space, controlability management of fuzzy differential equation is as much important issue as stability. This paper addresses exact controllability for fuzzy differential equations in the credibility space in the perspective of Liu process. This is an extension of the controllability results of Park et al. (Controllability for the semilinear fuzzy integro-differential equations with nonlocal conditions) to fuzzy differential equations driven by Liu process.