A fast algorithm is given for computing the optimal weight vector in antenna array pattern synthesis having a set of null constraints. The algorithm requires only a UDUT decomposition of an m + 1 × m + 1 real pos...
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A fast algorithm is given for computing the optimal weight vector in antenna array pattern synthesis having a set of null constraints. The algorithm requires only a UDUT decomposition of an m + 1 × m + 1 real positive definite matrix and the computation of the first row of the inverse of a triangular matrix of the same dimension, where m is the number of null constraints.
In this paper we present a fast time-domain algorithm to study the electromagnetic pulse heating on dispersive medium. Using the proposed fast algorithm, the long heating process can be compressed by accelerating ther...
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In this paper we present a fast time-domain algorithm to study the electromagnetic pulse heating on dispersive medium. Using the proposed fast algorithm, the long heating process can be compressed by accelerating thermal conduction and scaling the power dissipation density. Comparing with the previous computation of several pulse periods, the proposed algorithm can deal with the heating process up to billions of pulse periods. Besides, employing the proposed algorithm, we study a 2D water post heated by electromagnetic pulses. The results reveal that comparing with continuous microwave heating, pulse heating cannot improve temperature uniformity or enhance heating efficiency.
The main purpose of this paper is to solve the viscous Cahn-Hilliard equation via a fast algorithm based on the two time-mesh(TT-M)finite element(FE)method to ease the problem caused by strong *** TT-M FE algorithm in...
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The main purpose of this paper is to solve the viscous Cahn-Hilliard equation via a fast algorithm based on the two time-mesh(TT-M)finite element(FE)method to ease the problem caused by strong *** TT-M FE algorithm includes the following main computing ***,a nonlinear FE method is applied on a coarse time-meshτ_(c).Here,the FE method is used for spatial discretization and the implicit second-orderθscheme(containing both implicit Crank-Nicolson and second-order backward difference)is used for temporal ***,based on the chosen initial iterative value,a linearized FE system on time fine mesh is solved,where some useful coarse numerical solutions are found by Lagrange’s interpolation *** analysis for both stability and a priori error estimates is made in *** examples are given to demonstrate the validity of the proposed *** algorithm is compared with the traditional Galerkin FE method and it is evident that our fast algorithm can save computational time.
作者：
Bennett, MUMIST
Dept Chem Engn Environm Technol Ctr Manchester M60 1QD Lancs England
Where a small periodic signal is hidden in normally distributed noise, measurements in the tails of the distribution are much more sensitive to the presence of the signal than those closer to the mean. By calculating ...
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Where a small periodic signal is hidden in normally distributed noise, measurements in the tails of the distribution are much more sensitive to the presence of the signal than those closer to the mean. By calculating a power spectrum only of the extreme values, the signal can be retrieved at a slightly reduced statistical significance but with a substantially reduced calculational requirement. A simple theory is derived of the signal lost by neglecting measurements close to the mean, an algorithm is described to apply this to the autocorrelation method for calculating a power spectrum, and then this algorithm is applied both to simulated and to measured data. It is demonstrated that neglecting 75% of the data points leads to a speed-up in the calculation by a factor of 6-10 at a cost of a 1.3 dB, loss in SNR. In a situation where there is a very large number of measurements but limited calculational power, this translates into a gain in the averaged SNR of 3-4 dB. It is shown that this technique is faster than the FFT in calculating power spectra over up to as many as 250 frequency bins. Practically, this means that a 1.3 GHz PC requires less than twice real time to calculate a 50-point power spectrum over a bandwidth of 10 MHz.
This letter presents a fast algorithm for electromagnetic scattering by buried conducting plates of large size and arbitrary shape using the conjugate gradient (CG) method combined with fast Fourier transform (FFT), D...
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This letter presents a fast algorithm for electromagnetic scattering by buried conducting plates of large size and arbitrary shape using the conjugate gradient (CG) method combined with fast Fourier transform (FFT), Due to the use of FFT in handling the cyclic convolutions related to Toeplitz matrices, the Sommerfeld integrals' evaluation for the buried scattering problem, which is usually time consuming, has been reduced to a minimum. The memory required for this algorithm is of the order N-the number of unknowns-and the computational complexity is of order NiterNlogN (N-iter is the iteration number N-iter << N for large problems).
The use of homomorphic filtering in many problems involving nonlinear combination of signals requires complex logarithmic converters. A fast algorithm for digital logarithmic conversion is developed which uses simple ...
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The use of homomorphic filtering in many problems involving nonlinear combination of signals requires complex logarithmic converters. A fast algorithm for digital logarithmic conversion is developed which uses simple computer manipulations. The algorithm trades accuracy for speed, but is found to be adequate in a number of applications tested so far.
The present paper describes a new fast algorithm for inversion of confluent Vandermonde-like matrices. Our algorithm generalizes a scheme presented by Calvetti and Reichel [27] for fast inversion of Vandermonde-like m...
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The present paper describes a new fast algorithm for inversion of confluent Vandermonde-like matrices. Our algorithm generalizes a scheme presented by Calvetti and Reichel [27] for fast inversion of Vandermonde-like matrices.
A fast algorithm that finds the nearest neighbor (NN) of an unknown sample from a design set of labeled samples is proposed. This algorithm requires a quite moderate preprocessing effort and a rather excessive storage...
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A fast algorithm that finds the nearest neighbor (NN) of an unknown sample from a design set of labeled samples is proposed. This algorithm requires a quite moderate preprocessing effort and a rather excessive storage, but it accomplishes substantial computational savings during classification. The performance of the algorithm is described and compared to the performance of the conventional one. Results on simulated data are provided to illustrate the computational savings' that may be achieved using this fast algorithm.
Second-generation (2G) high-temperature superconducting (HTS) tapes are now capable of carrying very high transport current and promising for a wide range of applications. The critical current of HTS coils is importan...
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Second-generation (2G) high-temperature superconducting (HTS) tapes are now capable of carrying very high transport current and promising for a wide range of applications. The critical current of HTS coils is important for applications, such as superconducting electric machines, superconducting magnetic energy storage, and superconducting magnets. Therefore, precisely and quickly calculating critical current of HTS coils is very important for designing HTS devices. This paper provides a fast algorithm for evaluating critical current of HTS pancake coil. The fast algorithm is realized through a stationary model, which is based on finite element method (FEM) software. The stationary model means that the model is solved by stationary study instead of time-dependent study. To validate this method, a pancake HTS coil was wound and its critical current was measured. Meanwhile, an axial symmetric stationary model was built according to the geometry of the measured HTS coil. By comparing measured and calculated results, the effectiveness of the stationary model was demonstrated. Moreover, the stationary model is compared with H formulation model. The calculated results by the two models are nearly the same. However, by using stationary calculation, the stationary model can remarkably speed up the computational process. Due to the advantage of calculating speed, the stationary model can be used to characterize and design large-scale HTS applications.
A fast algorithm is presented for determining the linear complexity of a sequence with period p(n) over GF (q), where p is an odd prime, and where q is a prime and a primitive root (mod p(2)).
A fast algorithm is presented for determining the linear complexity of a sequence with period p(n) over GF (q), where p is an odd prime, and where q is a prime and a primitive root (mod p(2)).
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