• Title, Summary, Keyword: Travelling wave

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WAVEFRONT SOLUTIONS IN THE DIFFUSIVE NICHOLSON'S BLOWFLIES EQUATION WITH NONLOCAL DELAY

  • Zhang, Cun-Hua
    • Journal of applied mathematics & informatics
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    • v.28 no.1_2
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    • pp.49-58
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    • 2010
  • In the present article we consider the diffusive Nicholson's blowflies equation with nonlocal delay incorporated into an integral convolution over all the past time and the whole infinite spatial domain $\mathbb{R}$. When the kernel function takes a special function, we construct a pair of lower and upper solutions of the corresponding travelling wave equation and obtain the existence of travelling fronts according to the existence result of travelling wave front solutions for reaction diffusion systems with nonlocal delays developed by Wang, Li and Ruan (J. Differential Equations, 222(2006), 185-232).

NEW EXACT TRAVELLING WAVE SOLUTIONS OF SOME NONLIN EAR EVOLUTION EQUATIONS BY THE(G'/G)-EXPANSION METHOD

  • Lee, You-Ho;Lee, Mi-Hye;An, Jae-Young
    • Honam Mathematical Journal
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    • v.33 no.2
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    • pp.247-259
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    • 2011
  • In this paper, the $(\frac{G'}{G})$-expansion method is used to construct new exact travelling wave solutions of some nonlinear evolution equations. The travelling wave solutions in general form are expressed by the hyperbolic functions, the trigonometric functions and the rational functions, as a result many previously known solitary waves are recovered as special cases. The $(\frac{G'}{G})$-expansion method is direct, concise, and effective, and can be applied to man other nonlinear evolution equations arising in mathematical physics.

Study on Application of Wave Travelling Effect and Local Site Effect to Design Standard for Analysing Seismic Behavior of Long-Span Cable-Stayed Bridge (장대사장교의 지진거동 분석시 지반특성 및 파동전달효과를 고려한 설계기준 적용에 대한 고찰)

  • Park, Youn-Soo;Song, Young-Bong;Hyun, Ki-Hwyun;Lee, Soon Nam;Yang, Won Yeol
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.12 no.1
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    • pp.167-174
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    • 2008
  • Number of long-span bridge construction has been increased recently so that seismic consideration of design has become significant. To adapt such significance to design, seismic design in the newly revised 'Cable Steel Bridge Design Handbook' specifies some of wave travelling effect and local site effect. In this study, a cable-stayed bridge with main span of 500m is analysed having variables of uniform excitation, wave travelling effect, and wave travelling effect plus local site effect. Result shows that wave travelling effect in cable-stayed bridge affects considerably to its seismic response under weak soil condition even though the span length is relatively short. What's more, regardless of soil type, the seismic response has become higher for analysis with wave travelling effect and local site effect than with wave travelling effect only. Consequently, in seismic response analysis of long-span bridge, consideration should be given to application of wave travelling effect and local site effect.

Fault Location of Underground Cables Using Travelling Wave (반사파를 이용한 지중케이블의 고장점 탐지연구)

  • Sun, J.H.;Kang, D.S.;Ryoo, H.S.
    • Proceedings of the KIEE Conference
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    • pp.1972-1974
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    • 2000
  • In this paper, we made an experiment on fault location of underground cables with travelling wave. The 5C2V coaxial cables of 100, 200m length, connected with discharge gap, are used for simplifying model cable lines of power cable. And 100KHz -2MHz CT and HV probe are installed at one side of the ends. We made travelling pulse in discharge gab and then pulse travelled along the cable to the both ends. Therefore, it is detected in CT and HV probe. Measuring the time difference of the pulse start and arrival, we were able to obtain the distance of pulse travelling. Consequently, our experimental results show the possibility to detect fault location of underground cables with travelling wave.

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Digital Differential Relay for Transmission Line Protection Using Travelling Wave (진행파를 이용한 디지탈 송전선 보호계전기)

  • Kim, Sung-Soo;Park, Jong-Keun;Yeun, Man-Chul
    • Proceedings of the KIEE Conference
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    • pp.95-97
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    • 1988
  • A method of digital transmission line protection using travelling wave is presented. It is shown that the fault current appears as a difference of two quantities associated with the travelling wave at each terminal. The phasor of these quantities are extracted and transmitted to the other end via communication channel to detect the line fault.

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ANALYTIC TRAVELLING WAVE SOLUTIONS OF NONLINEAR COUPLED EQUATIONS OF FRACTIONAL ORDER

  • AN, JEONG HYANG;LEE, YOUHO
    • Honam Mathematical Journal
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    • v.37 no.4
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    • pp.411-421
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    • 2015
  • This paper investigates the issue of analytic travelling wave solutions for some important coupled models of fractional order. Analytic travelling wave solutions of the considered model are found by means of the Q-function method. The results give us that the Q-function method is very simple, reliable and effective for searching analytic exact solutions of complex nonlinear partial differential equations.

A Fault Location Algorithm Using Wavelet Transformation for HVDC Cables (웨이블렛 변환을 이용한 HVDC 케이블 고장점 표정 알고리즘)

  • Kwon, Young-Jin;Kang, Sang-Hee
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.8
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    • pp.1311-1317
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    • 2008
  • In this paper, a fault location algorithm using wavelet transform is proposed for HVDC cable lines. The arriving instants of the first and second fault-induced backward travelling waves can be detected by using wavelet transform. The fault distance is estimated by using the time difference between the two instants of backward travelling waves and the velocity of the travelling wave. To distinguish between the backward wave from fault point and the backward wave from the remote end, polarities of backward waves are used. The proposed algorithm is verified varying with fault distances and fault resistances in underground cables of VSC(voltage source converter) HVDC system and CSC(Current Source Converter) HVDC respectively. Performance evaluations of the proposed algorithm shows that it has good ability for a fault location of HVDC cable faults.

NEW EXACT SOLUTIONS OF SOME NONLINEAR EVOLUTION EQUATIONS BY SUB-ODE METHOD

  • Lee, Youho;An, Jeong Hyang
    • Honam Mathematical Journal
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    • v.35 no.4
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    • pp.683-699
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    • 2013
  • In this paper, an improved ($\frac{G^{\prime}}{G}$)-expansion method is proposed for obtaining travelling wave solutions of nonlinear evolution equations. The proposed technique called ($\frac{F}{G}$)-expansion method is more powerful than the method ($\frac{G^{\prime}}{G}$)-expansion method. The efficiency of the method is demonstrated on a variety of nonlinear partial differential equations such as KdV equation, mKd equation and Boussinesq equations. As a result, more travelling wave solutions are obtained including not only all the known solutions but also the computation burden is greatly decreased compared with the existing method. The travelling wave solutions are expressed by the hyperbolic functions and the trigonometric functions. The result reveals that the proposed method is simple and effective, and can be used for many other nonlinear evolutions equations arising in mathematical physics.

The FEA of the Travelling-wave Ultrasonic Motor (진행파형 초음파 모터의 유한요소해석)

  • Kim, Sung-Hyun;Park, Tae-Gone
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.681-684
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    • 2003
  • Piezoelectric motors have been successfully developed for various applications like autofocus drives in camera lenses and handling equipment for high-accuracy positioning. In this paper, the travelling-wave motor which used in the camera lense, using bending vibration of a ring was studied. The basic structure of the motor is same but we suggested a few parameters for considering their design. The parameter is different from sine and cosine region of the voltage of the ceramic surface, displacement according to the wave number difference, and the phase difference. Same size of ceramics and aluminium ring were used for the stator. As a result, the displacement is dependent on the wave number.

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NEW EXACT TRAVELLING WAVE SOLUTIONS FOR SOME NONLINEAR EVOLUTION EQUATIONS

  • Lee, Youho;An, Jaeyoung;Lee, Mihye
    • Journal of the Chungcheong Mathematical Society
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    • v.24 no.2
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    • pp.359-370
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    • 2011
  • In this work, we obtain new solitary wave solutions for some nonlinear partial differential equations. The Jacobi elliptic function rational expansion method is used to establish new solitary wave solutions for the combined KdV-mKdV and Klein-Gordon equations. The results reveal that Jacobi elliptic function rational expansion method is very effective and powerful tool for solving nonlinear evolution equations arising in mathematical physics.