• Title/Summary/Keyword: nonlinear damping term

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INTERVAL OSCILLATION THEOREMS FOR SECOND-ORDER DIFFERENTIAL EQUATIONS

  • Bin, Zheng
    • Journal of applied mathematics & informatics
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    • v.27 no.3_4
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    • pp.581-589
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    • 2009
  • In this paper, we are concerned with a class of nonlinear second-order differential equations with a nonlinear damping term and forcing term: $$(r(t)k_1(x(t),x'(t)))'+p(t)k_2(x(t),x'(t))x'(t)+q(t)f(x(t))=0$$. Passage to more general class of equations allows us to remove a restrictive condition usually imposed on the nonlinearity. And, as a consequence, our results apply to wider classes of nonlinear differential equations. Some illustrative examples are considered.

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Adaptive nonlinear control with modular design (모듈라 설계기법에 의한 적응 비서형 제어)

  • 현근호;양해원
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.633-635
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    • 1997
  • In this paper we present a scheme of adaptive backstepping controller for nonlinear system. Backstepping approach has recently been adopted as a design tool for nonlinear control and especially backstepping with modular design used to seperately design controller and identifier. In the modular design the nonlinear damping term is contained in controller for input-to-state stability (ISS). We compare the ISS controller, which used in general case, with the weak-ISS controller that attenuates the effect of nonlinear damping term and prove their advantages and disadvantages by simulation.

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Blow-up of Solutions for Higher-order Nonlinear Kirchhoff-type Equation with Degenerate Damping and Source

  • Kang, Yong Han;Park, Jong-Yeoul
    • Kyungpook Mathematical Journal
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    • v.61 no.1
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    • pp.1-10
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    • 2021
  • This paper is concerned the finite time blow-up of solution for higher-order nonlinear Kirchhoff-type equation with a degenerate term and a source term. By an appropriate Lyapunov inequality, we prove the finite time blow-up of solution for equation (1.1) as a suitable conditions and the initial data satisfying ||Dmu0|| > B-(p+2)/(p-2q), E(0) < E1.

Analysis of nonlinear gain in modulation characteristics of semiconductor lasers (반도체 레이저의 변조특성에서 비선형 이득에 관한 연구)

  • 엄진섭;김창봉
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.35D no.2
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    • pp.93-100
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    • 1998
  • In this paper we analyze the effect of nonlinear gain on laser modulation characteristics applying a small-signal analysis to the rate equation which includes a nonlinear gain term. Also we analyze the resonance frequency and the damping factor which determine laser modulation characteristics, define K factor which is the proportionality factor between resonance frequency and damping factor, and conclude that the decrease in K factor is due to increases in differential gain and no correlation between K factor and nonlinear gain is identified.

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Adaptive Nonlinear Artificial Dissipation Model for Computational Aeroacoustics (전산공력음향학을 위한 적응형 비선형 인공감쇄모형)

  • Kim Jae Wook;Lee Duck Joo
    • 한국전산유체공학회:학술대회논문집
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    • 2001.10a
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    • pp.11-19
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    • 2001
  • An adaptive nonlinear artificial dissipation model is presented for performing aeroacoustic computations by the high-order and high-resolution numerical schemes based on the central finite differences. An effective formalism of it is devised by combining a selective background smoothing term and a well-established nonlinear shock-capturing term which is for the temporal accuracy as well as the numerical stability. A conservative form of the selective background smoothing term is presented to keep accurate phase speeds of the propagating nonlinear waves. The nonlinear shock-capturing term that has been modeled by the second-order derivative term is combined with it to improve the resolution of discontinuities and stabilize the strong nonlinear waves. It is shown that the improved artificial dissipation model with an adaptive control constant which is independent of problem types reproduces the correct profiles and speeds of nonlinear waves, suppresses numerical oscillations near discontinuity and avoids unnecessary damping on the smooth linear acoustic waves. The feasibility and performance of the adaptive nonlinear artificial dissipation model are investigated by the applications to actual computational aeroacoustics problems.

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LOCAL EXISTENCE AND GLOBAL UNIQUENESS IN ONE DIMENSIONAL NONLINEAR HYPERBOLIC INVERSE PROBLEMS

  • Choi, Jong-Sung
    • Communications of the Korean Mathematical Society
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    • v.17 no.4
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    • pp.593-606
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    • 2002
  • We prove local existence and global uniqueness in one dimensional nonlinear hyperbolic inverse problems. The basic key for showing the local existence of inverse solution is the principle of contracted mapping. As an application, we consider a hyperbolic inverse problem with damping term.

APPLICATION OF ROTHE'S METHOD TO A NONLINEAR WAVE EQUATION ON GRAPHS

  • Lin, Yong;Xie, Yuanyuan
    • Bulletin of the Korean Mathematical Society
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    • v.59 no.3
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    • pp.745-756
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    • 2022
  • We study a nonlinear wave equation on finite connected weighted graphs. Using Rothe's and energy methods, we prove the existence and uniqueness of solution under certain assumption. For linear wave equation on graphs, Lin and Xie [10] obtained the existence and uniqueness of solution. The main novelty of this paper is that the wave equation we considered has the nonlinear damping term |ut|p-1·ut (p > 1).