• Title/Summary/Keyword: Nonlinear Approximation

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Adaptive controls for non-linear plant using neural network (신경회로망을 이용한 비선형 플랜트의 적응제어)

  • 정대원
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.215-218
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    • 1997
  • A dynamic back-propagation neural network is addressed for adaptive neural control system to approximate non-linear control system rather than static networks. It has the capability to represent the approximation of nonlinear system without mathematical analysis and to carry out the on-line learning algorithm for real time application. The simulated results show fast tracking capability and adaptive response by using dynamic back-propagation neurons.

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Robust adaptive fuzzy controller for an inverted pendulum

  • Seo, Sam-Jun;Kim, Dong-Sik
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.1267-1271
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    • 2003
  • This paper proposes an indirect adaptive fuzzy controller for general SISO nonlinear systems. No a priori information on bounding constants of uncertainties including reconstruction errors and optimal fuzzy parameters is needed. The control law and the update laws for fuzzy rule structure and estimates of fuzzy parameters and bounding constants are determined so that the Lyapunov stability of the whole closed loop system is guaranteed. The computer simulation results for an inverted pendulum system show the performance of the proposed robust adaptive fuzzy controller.

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The emotional evaluation of color pattern based on information fusion (정보융합 기법을 이용한 칼라 패턴의 감성 평가)

  • 김성환;엄경배;이준환
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2000.11a
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    • pp.23-27
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    • 2000
  • In this paper, we propose an emotional evaluation model based on information fusion. This model can transform the physical features of a color pattern to the emotional features. Our proposed model consists of the fuzzy logic system and neural network model. The evaluation values produced by them were fused. The model shows comparable performances to the neural network and fuzzy logic system for the approximation of the nonlinear transforms. We believe the evaluated results of a color pattern can be used to the emotion-based color image retrievals.

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Effects of Stem Wave on the Vertical Breakwater (해안구조물 전면의 Stem Wave 특성에 관한 연구)

  • 박효봉;윤한삼;류청로
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2001.10a
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    • pp.138-143
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    • 2001
  • Based on mild slope equation and parabolic approximation the forward diffraction of monochromatic waves by a straight breakwater are studied numerically. The characteristics and effects of stem wave along breakwater and the relations between the stem wave and incident wave angle are discussed.

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THE CONVERGENCE OF FINITE DIFFERENCE APPROXIMATIONS FOR SINGULAR TWO-POINT BOUNDARY VALUE PROBLEMS

  • Lee, H.Y.;Seong, J.M.;Shin, J.Y.
    • Journal of the Korean Mathematical Society
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    • v.36 no.2
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    • pp.299-316
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    • 1999
  • We consider two finite difference approxiamations to a singular boundary value problem arising in the study of a nonlinear circular membrane under normal pressure. It is shown that the rates of convergence are O(h) and O($h^2$), respectively. An iterative scheme is introduced which converges to the solution of the finite difference equations. Finally the numerical experiments are given

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Adomian Decomposition Method for Point Reactor Kinetics Problems

  • Cho, Young-Chul;Cho, Nam-Zin
    • Nuclear Engineering and Technology
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    • v.28 no.5
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    • pp.452-457
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    • 1996
  • A system, such as a reactor point kinetics equation, can be solved with Adomian Decomposition Method (ADM) which uses the notion that all solutions and operators can be expressed as an infinite sum of those basis states, like Adomian polynomials. In this work, ADM is applied to point reactor kinetics equations for step reactivity insertion, ramp input of reactivity, and nonlinear feedback cases without linearization approximation. The results of ADM are more accurate and faster than those of other existing methods, even though we use comparatively large time step sizes.

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ERROR ESTIMATES OF SEMIDISCRETE DISCONTINUOUS GALERKIN APPROXIMATIONS FOR THE VISCOELASTICITY-TYPE EQUATION

  • Ohm, Mi-Ray;Lee, Hyun-Young;Shin, Jun-Yong
    • Bulletin of the Korean Mathematical Society
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    • v.49 no.4
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    • pp.829-850
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    • 2012
  • In this paper, we adopt symmetric interior penalty discontinuous Galerkin (SIPG) methods to approximate the solution of nonlinear viscoelasticity-type equations. We construct finite element space which consists of piecewise continuous polynomials. We introduce an appropriate elliptic-type projection and prove its approximation properties. We construct semidiscrete discontinuous Galerkin approximations and prove the optimal convergence in $L^2$ normed space.

On the limit cycles of aeroelastic systems with quadratic nonlinearities

  • Chen, Y.M.;Liu, J.K.
    • Structural Engineering and Mechanics
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    • v.30 no.1
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    • pp.67-76
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    • 2008
  • Limit cycle oscillations of a two-dimensional airfoil with quadratic and cubic pitching nonlinearities are investigated. The equivalent stiffness of the pitching stiffness is obtained by combining the linearization and harmonic balance method. With the equivalent stiffness, the equivalent linearization method for nonlinear flutter analysis is generalized to address aeroelastic system with quadratic nonlinearity. Numerical example shows that good approximation of the limit cycle can be obtained by the generalized method. Furthermore, the proposed method is capable of revealing the unsymmetry of the limit cycle; however the ordinary equivalent linearization method fails to do so.

APPROXIMATION METHODS FOR A COMMON MINIMUM-NORM POINT OF A SOLUTION OF VARIATIONAL INEQUALITY AND FIXED POINT PROBLEMS IN BANACH SPACES

  • Shahzad, N.;Zegeye, H.
    • Bulletin of the Korean Mathematical Society
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    • v.51 no.3
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    • pp.773-788
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    • 2014
  • We introduce an iterative process which converges strongly to a common minimum-norm point of solutions of variational inequality problem for a monotone mapping and fixed points of a finite family of relatively nonexpansive mappings in Banach spaces. Our theorems improve most of the results that have been proved for this important class of nonlinear operators.

Robot Trajectory Control using Prefilter Type Chaotic Neural Networks Compensator (Prefilter 형태의 카오틱 신경망을 이용한 로봇 경로 제어)

  • 강원기;최운하김상희
    • Proceedings of the IEEK Conference
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    • 1998.06a
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    • pp.263-266
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    • 1998
  • This paper propose a prefilter type inverse control algorithm using chaotic neural networks. Since the chaotic neural networks show robust characteristics in approximation and adaptive learning for nonlinear dynamic system, the chaotic neural networks are suitable for controlling robotic manipulators. The structure of the proposed prefilter type controller compensate velocity of the PD controller. To estimate the proposed controller, we implemented to the Cartesian space control of three-axis PUMA robot and compared the final result with recurrent neural network(RNN) controller.

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