• Title/Summary/Keyword: Orthogonal polynomials

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INEQUALITIES FOR JACOBI POLYNOMIALS

  • Pyung, In Soo;Kim, Hae Gyu
    • Korean Journal of Mathematics
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    • v.12 no.1
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    • pp.67-75
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    • 2004
  • Paul Turan observed that the Legendre polynomials satisfy the inequality $P_n(x)^2-P_{n-1}(x)P_{n+1}(x)$ > 0, $-1{\leq}x{\leq}1$. And G. Gasper(ref. [6], ref. [7]) proved such an inequality for Jacobi polynomials and J. Bustoz and N. Savage (ref. [2]) proved $P^{\alpha}_n(x)P^{\beta}_{n+1}(x)-P^{\alpha}_{n+1}(x)P{\beta}_n(x)$ > 0, $\frac{1}{2}{\leq}{\alpha}$ < ${\beta}{\leq}{\alpha}+2.0$ < $x$ < 1, for the ultraspherical polynomials (respectively, Laguerre ploynomials). The Bustoz-Savage inequalities hold for Laguerre and ultraspherical polynomials which are symmetric. In this paper, we prove some similar inequalities for non-symmetric Jacobi polynomials.

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Trade-off Analysis in Multi-objective Optimization Using Chebyshev Orthogonal Polynomials

  • Baek Seok-Heum;Cho Seok-Swoo;Kim Hyun-Su;Joo Won-Sik
    • Journal of Mechanical Science and Technology
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    • v.20 no.3
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    • pp.366-375
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    • 2006
  • In this paper, it is intended to introduce a method to solve multi-objective optimization problems and to evaluate its performance. In order to verify the performance of this method it is applied for a vertical roller mill for Portland cement. A design process is defined with the compromise decision support problem concept and a design process consists of two steps: the design of experiments and mathematical programming. In this process, a designer decides an object that the objective function is going to pursuit and a non-linear optimization is performed composing objective constraints with practical constraints. In this method, response surfaces are used to model objectives (stress, deflection and weight) and the optimization is performed for each of the objectives while handling the remaining ones as constraints. The response surfaces are constructed using orthogonal polynomials, and orthogonal array as design of experiment, with analysis of variance for variable selection. In addition, it establishes the relative influence of the design variables in the objectives variability. The constrained optimization problems are solved using sequential quadratic programming. From the results, it is found that the method in this paper is a very effective and powerful for the multi-objective optimization of various practical design problems. It provides, moreover, a reference of design to judge the amount of excess or shortage from the final object.

A DIFFERENCE EQUATION FOR MULTIPLE KRAVCHUK POLYNOMIALS

  • Lee, Dong-Won
    • Journal of the Korean Mathematical Society
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    • v.44 no.6
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    • pp.1429-1440
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    • 2007
  • Let ${K^{(\vec{p};N)}_{\vec{n}}(x)}$ be a multiple Kravchuk polynomial with respect to r discrete Kravchuk weights. We first find a lowering operator for multiple Kravchuk polynomials ${K^{(\vec{p};N)}_{\vec{n}}(x)}$ in which the orthogonalizing weights are not involved. Combining the lowering operator and the raising operator by Rodrigues# formula, we find a (r+1)-th order difference equation which has the multiple Kravchuk polynomials ${K^{(\vec{p};N)}_{\vec{n}}(x)}$ as solutions. Lastly we give an explicit difference equation for ${K^{(\vec{p};N)}_{\vec{n}}(x)}$ for the case of r=2.

q-SOBOLEV ORTHOGONALITY OF THE q-LAGUERRE POLYNOMIALS {Ln(-N)(·q)}n=0 FOR POSITIVE INTEGERS N

  • Moreno, Samuel G.;Garcia-Caballe, Esther M.
    • Journal of the Korean Mathematical Society
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    • v.48 no.5
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    • pp.913-926
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    • 2011
  • The family of q-Laguerre polynomials $\{L_n^{(\alpha)}({\cdot};q)\}_{n=0}^{\infty}$ is usually defined for 0 < q < 1 and ${\alpha}$ > -1. We extend this family to a new one in which arbitrary complex values of the parameter ${\alpha}$ are allowed. These so-called generalized q-Laguerre polynomials fulfil the same three term recurrence relation as the original ones, but when the parameter ${\alpha}$ is a negative integer, no orthogonality property can be deduced from Favard's theorem. In this work we introduce non-standard inner products involving q-derivatives with respect to which the generalized q-Laguerre polynomials $\{L_n^{(-N)}({\cdot};q)\}_{n=0}^{\infty}$, for positive integers N, become orthogonal.

FRACTIONAL CALCULUS FORMULAS INVOLVING $\bar{H}$-FUNCTION AND SRIVASTAVA POLYNOMIALS

  • Kumar, Dinesh
    • Communications of the Korean Mathematical Society
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    • v.31 no.4
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    • pp.827-844
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    • 2016
  • Here, in this paper, we aim at establishing some new unified integral and differential formulas associated with the $\bar{H}$-function. Each of these formula involves a product of the $\bar{H}$-function and Srivastava polynomials with essentially arbitrary coefficients and the results are obtained in terms of two variables $\bar{H}$-function. By assigning suitably special values to these coefficients, the main results can be reduced to the corresponding integral formulas involving the classical orthogonal polynomials including, for example, Hermite, Jacobi, Legendre and Laguerre polynomials. Furthermore, the $\bar{H}$-function occurring in each of main results can be reduced, under various special cases.

Shape form Shading Using Surface Approximation by Orthogonal Polynomials (직교다항식에 의한 표면 근사화를 이요한 Shape form shading)

  • 김방환;박래홍
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.19 no.10
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    • pp.1880-1893
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    • 1994
  • In this paper, we propose a new shape from shading algorithm which reconstructs object shapes from a single image. In the proposed intative algorithm, given 3D surfaces are approximated by orthogonal polynomials and the relationships between the given surface and its derivatives are constructed ad matrix forms in terms of polynomial coefficients, Also the relative depth and its derivatives are obtained by updating them iteratively. Performance of the propose shape from shading algorithm is evaluated in terms of brightness error, orientation error, and height error, and the performance comparison of the proposed and conventional algorithms is shown.

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Free vibration analysis of elliptic and circular plates having rectangular orthotropy

  • Chakraverty, S.;Petyt, M.
    • Structural Engineering and Mechanics
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    • v.7 no.1
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    • pp.53-67
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    • 1999
  • The natural frequencies and modes of free vibration of specially orthotropic elliptic and circular plates are analysed using the Rayleigh-Ritz method. The assumed functions used are two-dimensional boundary characteristic orthogonal polynomials which are generated using the Gram-Schmidt orthogonalization procedure. The first five natural frequencies are reported here for various values of aspect ratio of the ellipse. Results are given for various boundary conditions at the edges i.e., the boundary may be any of clamped, simply-supported or fret. Numerical results are presented here for several orthotropic material properties. For rectilinear orthotropic circular plates, a few results are available in the existing literature, which are compared with the present results and are found to be in good agreement.

GENERALIZED Δ-COHERENT PAIRS

  • Kwon, K.H.;Lee, J.H.;F. Marcellan
    • Journal of the Korean Mathematical Society
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    • v.41 no.6
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    • pp.977-994
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    • 2004
  • A pair of quasi-definite linear functionals {u$_{0}$, u$_1$} is a generalized $\Delta$-coherent pair if monic orthogonal polynomials (equation omitted) relative to u$_{0}$ and u$_1$, respectively, satisfy a relation (equation omitted) where $\sigma$$_{n}$ and T$_{n}$ are arbitrary constants and $\Delta$p = p($\chi$+1) - p($\chi$) is the difference operator. We show that if {u$_{0}$, u$_1$} is a generalized $\Delta$-coherent pair, then u$_{0}$ and u$_{1}$ must be discrete-semiclassical linear functionals. We also find conditions under which either u$_{0}$ or u$_1$ is discrete-classical.ete-classical.