Multilevel Characteristic Basis Finite-Element Method (ML-CBFEM)-An Efficient Version of a Domain Decomposition Algorithm for Large-Scale Electromagnetic Problems

Ozgun, Ozlem
Mittra, Raj
Kuzuoğlu, Mustafa
We introduce a memory-efficient version of the Characteristic Basis Finite-Element Method (CBFEM), which combines the domain decomposition with the use of characteristic basis functions (CBFs) that are tailored for each individual subdomain. Although the conventional CBFEM is inherently an efficient approach, the final number of unknowns is primarily determined by the size (or the number) of the subdomains. The larger the size of the subdomains, or fewer the number, the less is the final number of unknowns. However, if we employ "large" subdomains, it is more difficult to generate CBFs for each subdomain due to the memory bottleneck in utilizing direct solution techniques employed to generate the CBFs. In the proposed multilevel approach, referred to herein as the Multilevel CBFEM (ML-CBFEM), we first decompose the computational domain into several "smaller" subdomains, and generate the CBFs for each subdomain in a conventional manner. Then, these bases are combined in a multilevel fashion to derive the CBFs for larger subdomains. In each level, the CBFs are created by using the bases in the lower level. This approach, also called "nested" CBFEM, leads to a considerable reduction in the matrix size and memory, and thus, makes use of direct solvers efficiently.


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Ozgun, Ozlem; Kuzuoğlu, Mustafa (Institute of Electrical and Electronics Engineers (IEEE), 2007-03-01)
We introduce the locally-conformal perfectly matched layer (PML) approach, which is an easy and straightforward PML implementation, to the problem of mesh truncation in the finite element method (FEM). This method is based on a locally-defined complex coordinate transformation which has no explicit dependence on the differential geometric characteristics of the PML-free space interface. As a result, it is possible to handle challenging PML geometries with interfaces having arbitrary curvature, especially th...
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Ozgun, O.; Kuzuoğlu, Mustafa (Institution of Engineering and Technology (IET), 2010-04-01)
The authors introduce the iterative leap-field domain decomposition method that is tailored to the finite element method, by combining the concept of domain decomposition and the Huygens' Principle. In this method, a large-scale electromagnetic boundary value problem is partitioned into a number of suitably-defined 'small' and manageable subproblems whose solutions are assembled to obtain the global solution. The main idea of the method is the iterative application of the Huygens' Principle to the fields ra...
CBFEM-MPI: A Parallelized Version of Characteristic Basis Finite Element Method for Extraction of 3-D Interconnect Capacitances
Ozgun, Ozlem; Mittra, Raj; Kuzuoğlu, Mustafa (Institute of Electrical and Electronics Engineers (IEEE), 2009-02-01)
In this paper, we present a novel, non-iterative domain decomposition method, which has been parallelized by using the message passing interface (MPI) library, and used to efficiently extract the capacitance matrixes of 3-D interconnect structures, by employing characteristic basis functions (CBFs) in the context of the finite element method (FEM). In this method, which is Failed CBFEM-MPI, the computational domain is partitioned into a number of nonoverlapping subdomains in which the CBFs are constructed b...
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Candan, Çağatay (Institution of Engineering and Technology (IET), 2012-08-01)
An implementation for the post-Doppler adaptive target detectors enabling an efficient change of the subspace dimension is described. The proposed implementation uses the order recursive structure of the conjugate directions method and does not present any additional computational burden on the processor. The implementation can be particularly useful for the adaptive detectors with an indeterminate number of auxiliary vectors for the clutter covariance matrix estimation. Through the proposed method, the sub...
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Haydar, A; Demirekler, Mübeccel; Yurtseven, MK (Institution of Engineering and Technology (IET), 1998-01-08)
The authors introduce the use of a genetic algorithm in the reduction of a 24 parameter (12 LPC derived cepstral coefficients +12 Delta-cepstral coefficients) set to a five, six, seven, eight or ten parameter set, for each speaker in text-independent speaker identification. The experimental results show that there is similar to 5% increase in the recognition rate when the reduced set of parameters is used.
Citation Formats
O. Ozgun, R. Mittra, and M. Kuzuoğlu, “Multilevel Characteristic Basis Finite-Element Method (ML-CBFEM)-An Efficient Version of a Domain Decomposition Algorithm for Large-Scale Electromagnetic Problems,” IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, pp. 3381–3387, 2009, Accessed: 00, 2020. [Online]. Available: