• 제목/요약/키워드: partial differential equation

검색결과 393건 처리시간 0.025초

보리의 상온 통풍건조 시뮬레이션(I) -실험치와 예측치의 비교- (Simulation of Natural Air Drying of Barley -Comparison of Experimental and Simulated Results-)

  • 금동혁;이선덕
    • Journal of Biosystems Engineering
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    • 제15권1호
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    • pp.44-51
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    • 1990
  • Four models in current use for cereal grain drying, equilibrium model, Morey model, partial differential equation model and simplified partial differential equation model, were modified to be suitable for natural air drying of barley. The predicted by the four models and experimental results were compared. Three models except equilibrium model predicted moisture comtent and grain temperature very well. But equilibrium model overpredicted moisture content and grain temperature of bottom layer. The degree of prediction of the four models for relative humidities of exhaust air didn't differ much from one another and equally the four models predicted relative humidity statisfatorily. Morey model took much shorter computing time than any other models. Therefore, considering the degree of prediction and computing time Morey model was the most suitable for natural air drying of barley.

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A Model for a Continuous State System with (s,S) Repair Policy

  • Park, Won-J.;Kim, Eui-Yong;Kim, Hong-Gie
    • Journal of the Korean Statistical Society
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    • 제25권1호
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    • pp.111-122
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    • 1996
  • A model for a system whose state changes continuously with time is introduced. It is assumed that the system is modeled by a Brownian motion with negative drift and an absorbing barrier at the origin. A repairman arrives according to a Poisson process and repairs the system according to an (s,S) policy, i.e., he increases the state of the system up to S if and only if the state is below s. A partial differential equation is derived for the distribution function of X(t), the state of the system at time t, and the Laplace-Stieltjes transform of the distribution function is obtained by solving the partial differential equation. For the stationary case the explicit expression is deduced for the distribution function of the stationary state of the system.

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

  • Lee, Youho;An, Jeong Hyang
    • 호남수학학술지
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    • 제35권4호
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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.

FOURIER'S TRANSFORM OF FRACTIONAL ORDER VIA MITTAG-LEFFLER FUNCTION AND MODIFIED RIEMANN-LIOUVILLE DERIVATIVE

  • Jumarie, Guy
    • Journal of applied mathematics & informatics
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    • 제26권5_6호
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    • pp.1101-1121
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    • 2008
  • One proposes an approach to fractional Fourier's transform, or Fourier's transform of fractional order, which applies to functions which are fractional differentiable but are not necessarily differentiable, in such a manner that they cannot be analyzed by using the so-called Caputo-Djrbashian fractional derivative. Firstly, as a preliminary, one defines fractional sine and cosine functions, therefore one obtains Fourier's series of fractional order. Then one defines the fractional Fourier's transform. The main properties of this fractal transformation are exhibited, the Parseval equation is obtained as well as the fractional Fourier inversion theorem. The prospect of application for this new tool is the spectral density analysis of signals, in signal processing, and the analysis of some partial differential equations of fractional order.

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APPLICATION OF PRODUCT OF THE MULTIVARIABLE A-FUNCTION AND THE MULTIVARIABLE SRIVASTAVA'S POLYNOMIALS

  • Kumar, Dinesh;Ayant, Frederic;Choi, Junesang
    • East Asian mathematical journal
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    • 제34권3호
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    • pp.295-303
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    • 2018
  • Gautam et al. [9] introduced the multivariable A-function, which is very general, reduces to yield a number of special functions, in particular, the multivariable H-function. Here, first, we aim to establish two very general integral formulas involving product of the general class of Srivastava multivariable polynomials and the multivariable A-function. Then, using those integrals, we find a solution of partial differential equations of heat conduction at zero temperature with radiation at the ends in medium without source of thermal energy. The results presented here, being very general, are also pointed out to yield a number of relatively simple results, one of which is demonstrated to be connected with a known solution of the above-mentioned equation.

Scalable Coding of Depth Images with Synthesis-Guided Edge Detection

  • Zhao, Lijun;Wang, Anhong;Zeng, Bing;Jin, Jian
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제9권10호
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    • pp.4108-4125
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    • 2015
  • This paper presents a scalable coding method for depth images by considering the quality of synthesized images in virtual views. First, we design a new edge detection algorithm that is based on calculating the depth difference between two neighboring pixels within the depth map. By choosing different thresholds, this algorithm generates a scalable bit stream that puts larger depth differences in front, followed by smaller depth differences. A scalable scheme is also designed for coding depth pixels through a layered sampling structure. At the receiver side, the full-resolution depth image is reconstructed from the received bits by solving a partial-differential-equation (PDE). Experimental results show that the proposed method improves the rate-distortion performance of synthesized images at virtual views and achieves better visual quality.

SINGULAR AND DUAL SINGULAR FUNCTIONS FOR PARTIAL DIFFERENTIAL EQUATION WITH AN INPUT FUNCTION IN H1(Ω)

  • Woo, Gyungsoo;Kim, Seokchan
    • East Asian mathematical journal
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    • 제38권5호
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    • pp.603-610
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    • 2022
  • In [6, 7] they introduced a new finite element method for accurate numerical solutions of Poisson equations with corner singularities. They consider the Poisson equations with homogeneous boundary conditions, compute the finite element solutions using standard FEM and use the extraction formula to compute the stress intensity factor(s), then they posed new PDE with a regular solution by imposing the nonhomogeneous boundary condition using the computed stress intensity factor(s), which converges with optimal speed. From the solution they could get an accurate solution just by adding the singular part. They considered a partial differential equation with the input function f ∈ L2(Ω). In this paper we consider a PDE with the input function f ∈ H1(Ω) and find the corresponding singular and dual singular functions. We also induce the corresponding extraction formula which are the basic element for the approach.

Solution of Poisson Equation using Isogeometric Formulation

  • Lee, Sang-Jin
    • Architectural research
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    • 제13권1호
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    • pp.17-24
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    • 2011
  • Isogeometric solution of Poisson equation is provided. NURBS (NonUniform B-spline Surface) is introduced to express both geometry of structure and unknown field of governing equation. The terms of stiffness matrix and load vector are consistently derived with very accurate geometric definition. The validity of the isogeometric formulation is demonstrated by using two numerical examples such as square plate and L-shape plate. From numerical results, the present solutions have a good agreement with analytical and finite element (FE) solutions with the use of a few cells in isogeometric analysis.

Bi-2212 고온초전도체 튜브의 자기확산에 관한 연구 (An experimental study of magnetic diffusion in Bi-2212 High-Tc supercondutor tube)

  • 정성기;설승윤
    • 한국초전도ㆍ저온공학회논문지
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    • 제5권2호
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    • pp.66-70
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    • 2003
  • Transient magnetic diffusion process in a melt-cast Bi2Sr2CaCu20X(Bi-2212) tube was studied by experimental and numerical analyses. The transient diffusion partial differential equation is transformed into an ordinary differential equation by integral method. The penetration depth of magnetic field into a superconducting tube is obtained by solving the differential equation numerically. The results show that the penetration depth as a function of time which is somewhat different from the results by Bean's critical state model. The reason of the difference between the present results and that of Bean's model is discussed and compared in this paper. This experiment measure the magnetic flux density in the supercondutor after supply direct-current of Bi-2212 rounded by copper coil. This study was discussed of valid of a previous numerical solution which is compared by the penetrate time and the magnetic flux density difference of between the present results and the numerical solution.

고온 초전도체 관에서의 과도 자기확산 해석 (Analysis of Transient Magnetic Diffusion in a High-Temperature Superconductor Tube)

  • 설승윤;정성기
    • 한국전기전자재료학회논문지
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    • 제15권11호
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    • pp.991-996
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    • 2002
  • Transient magnetic diffusion process in a melt-cast BSCCO-2212 tube is analyzed by an analytical method. The transient diffusion partial differential equation is transformed into an ordinary differential equation by integral method. The penetration depth of magnetic field into a superconducting tube is obtained by solving the differential equation numerically. The results show that the penetration depth as a function of time which is somewhat different from the results by Bean's critical state model. The reason of the difference between the present results and that of Bean's model is discussed and compared in this paper.