• Title/Summary/Keyword: Schrodinger wave equation

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A LINEARIZED FINITE-DIFFERENCE SCHEME FOR THE NUMERICAL SOLUTION OF THE NONLINEAR CUBIC SCHRODINGER EQUATION

  • Bratsos, A.G.
    • Journal of applied mathematics & informatics
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    • v.8 no.3
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    • pp.683-691
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    • 2001
  • A linearized finite-difference scheme is used to transform the initial/boundary-value problem associated with the nonlinear Schrodinger equation into a linear algebraic system. This method is developed by replacing the time and the nonlinear term by an appropriate parametric linearized scheme based on Taylor’s expansion. The resulting finite-difference method is analysed for stability and convergence. The results of a number of numerical experiments for the single-soliton wave are given.

On the Evolution of Leading Waves Generated by a Wavemaker (조파기에 의하여 발생된 선단파의 전개)

  • 박인규;최항순
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.4 no.3
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    • pp.156-160
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    • 1992
  • The evolution of leading waves generated by a wavemaker in a two-dimensional tank has been studied. The front of wave trains can be described in general by the Schrodinger equation. In particular, when the slope of the carrier waves is steep, and hence nonlinearity becomes important, the cubic Schrodinger equation is proved to be an appropriate mathematical model. Computations are made by using the Crank-Nicolson algorithm and compared with experimental data. It is found that the numerical result predicts the evolution of leading waves fairly well and the evolution is significantly affected by nonlinearity for steep waves when kh>1.36.

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π/2 Pulse Shaping via Inverse Scattering of Central Potentials

  • 이창재
    • Bulletin of the Korean Chemical Society
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    • v.17 no.2
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    • pp.188-192
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    • 1996
  • It is shown that the inversion of the undamped Bloch equation for an amplitude-modulated broadband π/2 pulse can be precisely treated as an inverse scattering problem for a Schrodinger equation on the positive semiaxis. The pulse envelope is closely related to the central potential and asymptotically the wave function takes the form of a regular solution of the radial Schrodinger equation for s-wave scattering. An integral equation, which allows the calculation of the pulse amplitude (the potential) from the phase shift of the asymptotic solution, is derived. An exact analytical inversion of the integral equation shows that the detuning-independent π/2 pulse amplitude is given by a delta function. The equation also provides a means to calculate numerically approximate π/2 pulses for broadband excitation.

Mach Reflection of Sinusoidally-Modulated Nonlinear Stokes Waves by a Thin Wedge

  • Choi, Hang-S.;Chee, Won-S.
    • Selected Papers of The Society of Naval Architects of Korea
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    • v.1 no.1
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    • pp.45-51
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    • 1993
  • By using multiple-scale expansion techniques, the Mach reflection of sinusoidally- modulated nonlinear Stokes waves by a stationary thin wedge has been studied within the framework of potential theory. It is shown that the evolution of diffracted wave amplitude can be described by the Zakharov equation to the loading order and that It reduces to the cubic Schrodinger equation with an additional linear term in the case of stable modulations. Computations are made for the cubic Schrodinger equation for different values of nonlinear and dispersion parameters. Numerical results reflect the experimental findings in terms of the amplitude and width of generated stem waves. Based on the computations it is concluded that the nonlinearity dominates the wave field, while the dispersion does not significantly affect the wave evolution.

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APPLICATIONS OF THE WEIGHTED SCHEME FOR GNLS EQUATIONS IN SOLVING SOLITON SOLUTIONS

  • Zhang, Tiande;Cao, Qingjie;Price, G.W.;Djidjeli, K.;Twizell, E.H.
    • Journal of applied mathematics & informatics
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    • v.5 no.3
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    • pp.615-632
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    • 1998
  • Soliton solutions of a class of generalized nonlinear evo-lution equations are discussed analytically and numerically which is achieved using a travelling wave method to formulate one-soliton solution and the finite difference method to the numerical dolutions and the interactions between the solitons for the generalized nonlinear Schrodinger equations. The characteristic behavior of the nonlinear-ity admitted in the system has been investigated and the soliton state of the system in the limit of $\alpha\;\longrightarrow\;0$ and $\alpha\;\longrightarrow\;\infty$ has been studied. The results presented show that soliton phenomena are character-istics associated with the nonlinearities of the dynamical systems.

Analysis of a Dipole Antenna Using Maxwell-SCHRÖDINGER Equation (맥스웰-슈뢰딩거 방정식을 이용한 다이폴 안테나 해석)

  • Kim, Jinyoung;Jung, Jaeyoung;Jung, Youngbae;Jung, Changwon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.5
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    • pp.3107-3113
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    • 2014
  • We present a quantitative analysis of a dipole antenna and its characteristics from the viewpoint of quantum mechanics. The method makes use of a Maxwell equation used in an existing antenna propagation formula. This includes radiation resistance, input reactance, and antenna efficiency as functions of frequency and antenna length. Particular attention is paid to the Schr$\ddot{o}$odinger equation. We accomplish E-field and H-field analyses of a dipole antenna by combining the Maxwell and Schr$\ddot{o}$odinger wave equations. When comparing the existing Maxwell wave equation with the Schr$\ddot{o}$odinger wave equation, quantum-electric movement is more accurate than using the Maxwell wave equation alone.

A Study of the Characteristics and Mechanism of Giant wave Appearance (대양에서의 거대파랑 출현 특성과 기구에 관한 연구)

  • Shin Seung-Ho;Hong Keyyong
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2005.10a
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    • pp.147-152
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    • 2005
  • 선형파 이론에 의한 파랑스펙트럼 분포에 의해서는 30m 크기의 파랑은 현실적으로 거의 발생 불가능하다고 인식되어 왔다. 그러나 최근의 위성 영상을 이용한 조사에 의해 3주간의 기간 통안 25m 이상의 거대파가 10개 이상 관측됨에 따라 실해역에서 빈번히 마주칠 수 있는 현상임이 입증되었으며 이에 따라 지금까지 이유 불명으로 치부되어 왔던 많은 해양 재난이 거대파에 의해 발생했던 것으로 추정되고 있다. 거대파의 발생원인은 파군 형성과 관련한 파고분포 특성의 변화, 전파하는 파군의 비선형 공명간섭 통이 제기되고 있으나, 그 출현의 복잡성과 자료의 부족 등으로 아직 명확하게 해명되지 못하고 있다. 본 연구에서는 실해역에서 발생하는 거대파의 특성 및 선형 및 비선형이론에 근거한 거대파 발생 기구를 고찰하고 비선형 파랑전파를 모사할 수 있는 수치모형을 개발하였다.

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Nonlinear Diffraction of Incident Waves with Side-band Disturbances by a Thin Wedge (변조된 입사파의 쐐기에 의한 산란)

  • 지원식;최항순
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.3 no.1
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    • pp.45-53
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    • 1991
  • The nonlinear forward diffraction of a modulated wave train by a thin wedge has been studied analytically. Since the physical variables involved in the problem have vastly different scales, the multiple scale expansion method has been used to obtain an approximate solution. To simplify the problem. the wedge is assumed to be thin and the parabolic approximation is utilized. The wave evolution can be described by a kind of the cubic Schrodinger equation. which consists of the linear time evolution. the lateral dispersion and the nonlinearity. Numerical results indicate that the nonlinearity. which it defined by the ratio of the ratio of the incident wave to the wedge angle. governs the amplitude and the stability of diffracted waves. The instability of dirffracted waves becomes more pronounced as the nonlinearity increases and the modulation ratio decreases. It is also found that the stem waves. initially developed along the wedge. can not sustain for a long time.

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Analysis of Tunnelling Rate Effect on Single Electron Transistor

  • Sheela, L.;Balamurugan, N.B.;Sudha, S.;Jasmine, J.
    • Journal of Electrical Engineering and Technology
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    • v.9 no.5
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    • pp.1670-1676
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    • 2014
  • This paper presents the modeling of Single Electron Transistor (SET) based on Physical model of a device and its equivalent circuit. The physical model is derived from Schrodinger equation. The wave function of the electrode is calculated using Hartree-Fock method and the quantum dot calculation is obtained from WKB approximation. The resulting wave functions are used to compute tunneling rates. From the tunneling rate the current is calculated. The equivalent circuit model discuss about the effect of capacitance on tunneling probability and free energy change. The parameters of equivalent circuit are extracted and optimized using genetic algorithm. The effect of tunneling probability, temperature variation effect on tunneling rate, coulomb blockade effect and current voltage characteristics are discussed.