• Article  

      The Almansi method of fundamental solutions for solving biharmonic problems 

      Karageorghis, Andreas; Fairweather, G. (1988)
      A new fundamental solutions method for the numerical solution of two‐dimensional biharmonic problems is described. In this method, which is based on the Almansi representation of a biharmonic function in the plane, the ...
    • Article  

      Cubic and quintic spline-on-spline interpolation 

      Papamichael, Nicolas; Soares, Maria Joana (1987)
      This paper is concerned with the cubic spline-on-spline procedure considered by Dolezal and Tewarson [3]. We show that when the knots are equally spaced, with spacing h, then the order of accuracy of the spline-on-spline ...
    • Article  

      Cubic spline interpolation of harmonic functions 

      Papamichael, Nicolas; Whiteman, J. R. (1974)
      It is shown that for the two dimensional Laplace equation a univariate cubic spline approximation in either space direction together with a difference approximation in the other leads to the well-known nine-point ...
    • Article  

      A cubic spline method for the solution of a linear fourth-order two-point boundary value problem 

      Papamichael, Nicolas; Worsey, A. J. (1981)
      A cubic spline method is described for the numerical solution of a two-point boundary value problem, involving a fourth order linear differential equation. This spline method is shown to be closely related to a known fourth ...
    • Article  

      End conditions for improved cubic spline derivative approximations 

      Papamichael, Nicolas; Worsey, A. J. (1981)
      We consider the problem of deriving accurate end conditions for cubic spline interpolation at equally spaced knots. In particular we derive a number of end conditions which lead to derivative approximations of high accuracy. ...
    • Article  

      End conditions for interpolatory cubic splines with unequally spaced knots 

      Behforooz, G. H.; Papamichael, Nicolas (1980)
      A class of end conditions is derived for cubic spline interpolation at unequally spaced knots. These conditions are in terms of function values at the knots and lead to 0 (h4) convergence uniformly on the interval of ...
    • Article  


      Ioannou, Petros A.; Tao, Gang (1987)
      Frequency-domain conditions for strictly positive real (SPR) functions which appear in literature are often only necessary or only sufficient. This point is raised by B. D. O. Anderson and S. Vongpanitlerd (1973), and J. ...
    • Article  

      Improved orders of approximation derived from interpolatory cubic splines 

      Behforooz, G. H.; Papamichael, Nicolas (1979)
      Let s be a cubic spline, with equally spaced knots on [a, b] interpolating a given function y at the knots. The parameters which determine s are used to construct a piecewise defined polynomial P of degree four. It is shown ...
    • Article  

      Numerical techniques for conformal mapping onto a rectangle 

      Papamichael, Nicolas; Kokkinos, C. A.; Warby, M. K. (1987)
      This paper is concerned with the problem of determining approximations to the function F which maps conformally a simply-connected domain Ω onto a rectangle R, so that four specified points on ∂Ω are mapped respectively ...
    • Article  

      Numerical techniques for two-dimensional laplacian problems 

      Papamichael, Nicolas; Symm, G. T. (1975)
      Two numerical methods, an integral equation method and a conformal transformation method, are described for the solution of harmonic boundary value problems. The methods are designed to deal with problems involving curved ...
    • Article  

      Pole-type singularities and the numerical conformal mapping of doubly-connected domains 

      Papamichael, Nicolas; Warby, M. K. (1984)
      Let f be the function which maps conformally a given doubly-connected domain Ω onto a circular annulus, and let H(z)= f′(z) f(z)- 1 z. In this paper we consider the problem of determining the main singularities of the ...
    • Article  

      Robust model reference adaptive control for multivariable plants 

      Tao, G.; Ioannou, Petros A. (1988)
      A complete procedure for generating and analysing robust model reference adaptive control schemes for multivariable plants is developed. The procedure consists of two parts: the first part involves the characterization of ...
    • Article  

      The treatment of corner and pole-type singularities in numerical conformal mapping techniques 

      Papamichael, Nicolas; Warby, M. K.; Hough, D. M. (1986)
      This paper is a report of recent developments concerning the nature and the treatment of singularities that affect certain numerical conformal mapping techniques. The paper also includes some new results on the nature of ...
    • Article  

      Two numerical methods for the conformal mapping of simply-connected domains 

      Papamichael, Nicolas; Kokkinos, C. A. (1981)
      Two numerical methods are considered for the conformai mapping of a bounded simply-connected domain onto the unit disc. The two methods are respectively the Bergman kernel method, which has been described in [17], and the ...