Browsing Τμήμα Μαθηματικών και Στατιστικής / Department of Mathematics and Statistics by Author "Karageorghis, Andreas"
Now showing items 1-20 of 170
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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 ...
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Article
Application of the MFS to inverse obstacle scattering problems
Karageorghis, Andreas; Lesnic, D. (2011)In this paper, the method of fundamental solutions (MFS) is used to detect the shape, size and location of a scatterer embedded in a host acoustic homogeneous medium from scant measurements of the scattered acoustic pressure ...
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Book
The boundary element method for the numerical solution of partial differential equations
Karageorghis, Andreas; Aitchison, J. (1984)
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Doctoral Thesis
The boundary element method for the numerical solution of partial differential equations. [electronic resource]
Karageorghis, Andreas (University of Oxford, 1984)
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Article
A chebyshev spectral collocation method for the computation of buoyancy-induced flows
Karageorghis, Andreas; Sivaloganathan, S. (1993)A spectral/Powell-hybrid algorithm is presented for the solution of the Boussinesq equations. The method is applied to a streamfunction formulation of the governing equations and used to solve the "double-glazing" test ...
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Article
A chebyshev spectral collocation method for the solution of the reynolds equation of lubrication
Raad, P. E.; Karageorghis, Andreas (1993)A multi-domain, Chebyshev collocation method is presented for the solution of ultra-thin gas bearing problems. The behavior of the flow varies across the computational domain with very sharp gradients occurring in the side ...
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Article
Chebyshev spectral collocation methods for laminar flow through a channel contraction
Karageorghis, Andreas; Phillips, T. N. (1989)A Chebyshev spectral element method is described for solving the Navier-Stokes equations in a channel contraction. The flow region is divided into two semi-infinite elements. The governing equation for the stream function ...
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Article
Chebyshev spectral methods for solving two-point boundary value problems arising in heat transfer
Karageorghis, Andreas (1988)The performance of Chebyshev spectral methods for solving nonlinear two-point boundary value problems is tested on several such problems arising in heat transfer. The collocation and the Galerkin spectral formulations are ...
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Article
Compact optimal quadratic spline collocation methods for the Helmholtz equation
Fairweather, G.; Karageorghis, Andreas; Maack, J. (2011)Quadratic spline collocation methods are formulated for the numerical solution of the Helmholtz equation in the unit square subject to non-homogeneous Dirichlet, Neumann and mixed boundary conditions, and also periodic ...
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Article
Conditioning of pseudospectral matrices for certain domain decompositions
Karageorghis, Andreas; Paprzycki, M. (1999)In this paper we examine the conditioning of the matrices resulting from certain conforming pseudospectral approximations. In particular, we consider non-conforming domain decompositions in rectangular domains and the ...
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Article
Conformal mapping for the efficient MFS solution of Dirichlet boundary value problems
Karageorghis, Andreas; Smyrlis, Yiorgos-Sokratis (2008)In this work, we use conformal mapping to transform harmonic Dirichlet problems of Laplace's equation which are defined in simply-connected domains into harmonic Dirichlet problems that are defined in the unit disk. We ...
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Article
Conformal Mapping for the Efficient Solution of Poisson Problems with the Kansa-RBF Method
Liu, X. -Y; Chen, C. S.; Karageorghis, Andreas (2017)We consider the solution of Poisson Dirichlet problems in simply-connected irregular domains. These domains are conformally mapped onto the unit disk and the resulting Poisson Dirichlet problems are solved efficiently using ...
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Article
Conforming chebyshev spectral collocation methods for the solution of laminar flow in a constricted channel
Karageorghis, Andreas; Phillips, T. N. (1991)The numerical simulation of steady planar two-dimensional laminar flow of an incompressible fluid through an abruptly contracting channel using spectral domain decomposition methods is described. The key features of the ...
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Article
Conforming Chebyshev spectral methods for Poisson problems in rectangular domains
Karageorghis, Andreas (1993)Four and six-element conforming domain decomposition techniques are developed for Chebyshev spectral collocation methods for Poisson problems in rectangular domains. The applicability of the methods is demonstrated on ...
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Article
Conforming spectral approximations for non-conforming domain decompositions
Karageorghis, Andreas; Sivaloganathan, S. (1998)A spectral domain decomposition scheme is introduced for the numerical solution of second- and fourth-order elliptic problems. The technique is applicable to certain domain decompositions of rectangular or rectangularly ...
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Article
A conforming spectral collocation strategy for Stokes flow through a channel contraction
Phillips, T. N.; Karageorghis, Andreas (1991)A spectral collocation method is described for solving the stream function formulation of the Stokes problem in a contraction geometry. The flow region is decomposed into a number of conformal rectangular subregions. A ...
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Article
Conforming spectral domain decomposition schemes
Karageorghis, Andreas (1997)Spectral domain decomposition schemes are presented for the numerical solution of second and fourth order problems. These schemes, which are formulated in the collocation framework yield spectral approximations which are ...
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Article
Conforming spectral methods for Poisson problems in cuboidal domains
Karageorghis, Andreas (1994)A Chebyshev collocation strategy is introduced for the subdivision of cuboids into cuboidal subdomains (elements). These elements are conforming, which means that the approximation to the solution is C0 continuous at all ...
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Article
A conforming spectral technique for biharmonic-type problems in rectangular domains
Karageorghis, Andreas (1994)A conforming domain decomposition Chebyshev spectral collocation method is developed for the solution of biharmonic-type problems in rectangular domains. Careful selection of the collocation points ensures that the solution ...
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Article
Detection of cavities using the method of fundamental solutions
Karageorghis, Andreas; Lesnic, D. (2009)The determination of the boundary of a cavity, defined here as a perfectly insulated inclusion, within a conducting medium from a single voltage and current flux measurements on the accessible boundary of the medium, can ...