• 제목/요약/키워드: Nonlinear differential system

검색결과 373건 처리시간 0.024초

AN ABS ALGORITHM FOR SOLVING SINGULAR NONLINEAR SYSTEMS WITH RANK ONE DEFECT

  • Ge, Ren-Dong;Xia, Zun-Quan
    • Journal of applied mathematics & informatics
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    • 제9권1호
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    • pp.167-183
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    • 2002
  • A modified discretization ABS algorithm for solving a class of singular nonlinear systems, F($\chi$)=0, where $\chi$, F $\in$ $R^n$, is presented, constructed by combining a discretization ABS algorithm arid a method of Hoy and Schwetlick (1990). The second order differential operation of F at a point is not required to be calculated directly in this algorithm. Q-quadratic convergence of this algorithm is given.

Nonlinear stability and bifurcations of an axially accelerating beam with an intermediate spring-support

  • Ghayesh, Mergen H.;Amabili, Marco
    • Coupled systems mechanics
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    • 제2권2호
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    • pp.159-174
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    • 2013
  • The present work aims at investigating the nonlinear dynamics, bifurcations, and stability of an axially accelerating beam with an intermediate spring-support. The problem of a parametrically excited system is addressed for the gyroscopic system. A geometric nonlinearity due to mid-plane stretching is considered and Hamilton's principle is employed to derive the nonlinear equation of motion. The equation is then reduced into a set of nonlinear ordinary differential equations with coupled terms via Galerkin's method. For the system in the sub-critical speed regime, the pseudo-arclength continuation technique is employed to plot the frequency-response curves. The results are presented for the system with and without a three-to-one internal resonance between the first two transverse modes. Also, the global dynamics of the system is investigated using direct time integration of the discretized equations. The mean axial speed and the amplitude of speed variations are varied as the bifurcation parameters and the bifurcation diagrams of Poincare maps are constructed.

EXISTENCE OF POSITIVE SOLUTIONS FOR THE SECOND ORDER DIFFERENTIAL SYSTEMS WITH STRONGLY COUPLED INTEGRAL BOUNDARY CONDITIONS

  • Lee, Eun Kyoung
    • East Asian mathematical journal
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    • 제34권5호
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    • pp.651-660
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    • 2018
  • This paper concerned the existence of positive solutions to the second order differential systems with strongly coupled integral boundary value conditions. By using Krasnoselskii fixed point theorem, we prove the existence of positive solutions according to the parameters under the proper nonlinear growth conditions.

Nonlinear vibration analysis of the viscoelastic composite nanoplate with three directionally imperfect porous FG core

  • Mohammadia, M.;Rastgoo, A.
    • Structural Engineering and Mechanics
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    • 제69권2호
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    • pp.131-143
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    • 2019
  • In this study, the nonlinear vibration analysis of the composite nanoplate is studied. The composite nanoplate is fabricated by the functional graded (FG) core and lipid face sheets. The material properties in the FG core vary in three directions. The Kelvin-Voigt model is used to study the viscoelastic effect of the lipid layers. By using the Von-Karman assumptions, the nonlinear differential equation of the vibration analysis of the composite nanoplate is obtained. The foundation of the system is modeled by the nonlinear Pasternak foundation. The Bubnov-Galerkin method and the multiple scale method are used to solve the nonlinear differential equation of the composite nanoplate. The free and force vibration analysis of the composite nanoplate are studied. A comparison between the presented results and the reported results is done and good achievement is obtained. The reported results are verified by the results which are obtained by the Runge-Kutta method. The effects of different parameters on the nonlinear vibration frequencies, the primary, the super harmonic and subharmonic resonance cases are investigated. This work will be useful to design the nanosensors with high biocompatibility.

암 치료를 위한 면역반응의 체계적인 연구 (A Systems Approach to Immune Response for Cancer Treatment)

  • 이권순
    • 대한의용생체공학회:의공학회지
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    • 제13권3호
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    • pp.181-188
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    • 1992
  • This paper provides an overview of system analysis of immunology. The theoretical research in this area is aimed at an understanding of the precise manner by which the immune system controls Infec pious diseases, cancer, and AIDS. This can provide a systematic plan for immunological experimentation by means of an integrated program of immune system analysis, mathematical modeling and computer simulation. Biochemical reactions and cellular fission are naturally modeled as nonlinear dynamical processes to synthesize the human immune system! as well as the complete organism it is intended to protect. A foundation for the control of tumors is presented, based upon the formulation of a realistic, knowledge based mathematical model of the interaction between tumor cells and the immune system. Ordinary bilinear differential equations which are coupled by such nonlinear term as saturation are derived from the basic physical phenomena of cellular and molecular conservation. The parametric control variables relevant to the latest experimental data are also considered. The model consists of 12 states, each composed of first-order, nonlinear differential equations based on cellular kinetics and each of which can be modeled bilinearly. Finally, tumor control as an application of immunotherapy is analyzed from the basis established.

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비선형 불규칙 진동 보의 등가에너지법에 의한 선형화 (Linearization of Nonlinear Random Vibration Beam by Equivalent Energy Method)

  • 이신영
    • 한국공작기계학회논문집
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    • 제17권1호
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    • pp.71-76
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    • 2008
  • Nonlinear dynamic system under random excitation was analyzed by using stochastic method. A linearization method was used in order to linearize non-linear structural characteristics but the parametric excitation was used as it was given. An equivalent energy method which equalizes the expectation value of energy of the original nonlinear system and that of quasi-linearized system was proposed. Ito's differential rule was applied to obtain steady state moments. Quasi-linearization coefficients can be obtained the iterative calculation of linearization scheme and steady state moments. Monte Carlo simulation was used to verify the results of the proposed method. Nonlinear vibration of a slender beam was analyzed in this research. The analysis results were compared with Monte Carlo simulation result and showed good agreement. As the spectral density of the given excitation increased, the analysis results showed the better agreement with Monte Carlo simulation.

VAXIMA를 이용한 비선형 보존 동역학계의 해석 (Analysis of a Nonlinear Conservative Dynamical System Using VAXIMA)

  • 이원경
    • 대한기계학회논문집
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    • 제14권3호
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    • pp.755-760
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    • 1990
  • 본 연구에서는 Lindstedt-Poincare 방법을 이용하여, Duffing 진동계에 5차항 을 포함시킴으로써 진폭이 더 큰 운동에도 타당성이 있는 근사해를 구하고자 한다. VAXIMA를 사용하여 해석하는 과정은 부록에 첨부되어 있으며 이 작업은 VAX 11/750 컴 퓨터에서 수행된 것이다.

블럭펄스함수를 이용한 비선형확률시스템의 칼만필터 설계 (Design of Kalman Filter of Nonlinear Stochastic System via BPF)

  • 안두수;임윤식;송인명;이명규
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1996년도 하계학술대회 논문집 B
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    • pp.1089-1091
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    • 1996
  • This paper presents a design method of Kalman Filter on continuous nonlinear stochastic system via BPF(Block Pulse Function). When we design Kalman Filter on nonlinear stochastic system, we must linearize this systems. In this paper, we uses the adaptive approach scheme and BPF for linearizing of nonlinear system and solving the Riccati differential equation which is usually guite difficult. This method proposed in this paper is simple and have computational advantages. Furthermore this method is very applicable to analysis and design of Kalman Filter on nonlinear stochastic systems.

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