Results 271 to 280 of about 13,478,919 (312)

Methods for GVB and Extended Wavefunctions and for DFT

2021
Initially, my goal as a GS was to extract from QM unique new concepts into how chemical bonding determines the remarkable varieties of structures, properties, and reactivity. However the new GVB wave functions required more sophisticated methods to optimize the wave functions. We describe here some of these advances.
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Fast polynomial transform methods for multidimensional DFTs

ICASSP '80. IEEE International Conference on Acoustics, Speech, and Signal Processing, 2005
In this paper, we introduce a new fast computation algorithm for multidimensional DFTs. This method maps efficiently some multidimensional DFTs into one-dimensional DFTs by using a single polynomial transform and auxiliary calculations. The polynomial transform is computed without multiplications and all calculations are performed with a reduced number
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An alternative method to zero-padded DFT

Measurement, 2015
Abstract Zero-padding method is usually used to increase the number of points in the DFT and consequently to improve the DFT’s approximation of the DTFT. This way the picket fence effect is reduced and a better approximation of DTFT local peaks is achieved for a finite number of measured points.
Codrin Donciu, Marinel Temneanu
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Impedance Measurement Method Based on DFT

2010
A principle of the impedance measurement based on DFT is proposed, and an implementation of the principle is designed. The principle raises the requirement of a 2-channel simultaneous sampling. In order to satisfy the requirement with a single A/D converter, both a hardware solution and a software solution are proposed, and the latter, which in fact is
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An efficient method of DFT/LDA band-gap correction

Computer Physics Communications, 2013
Abstract It has been shown that the underestimated by DFT/LDA(GGA) band-gap can be efficiently corrected by an averaging procedure of transition energies over a region close to the direct band-gap transition, which we call the Δ ( E I G ) method (the differences in the Kohn–Sham eigenvalues).
Pawel Scharoch, Maciej Winiarski
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DFT + DFD: An Integrated Method for Design for Testability and Diagnosability

2010 19th IEEE Asian Test Symposium, 2010
While conventional test point insertions commonly used in design for testability can improve fault coverage, the test points selected may not necessarily be the best candidates to aid silicon diagnosis. In this paper, test point insertions are conducted with the aim to detect more faults and also synergistically distinguish currently indistinguishable ...
Nikhil P. Rahagude, Maheshwar Chandrasekar, Michael S. Hsiao   +2 more
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Efficient Implicit Solvation Method for Full Potential DFT

Journal of Chemical Theory and Computation, 2017
With the advent of efficient electronic structure methods, effective continuum solvation methods have emerged as a way to, at least partially, include solvent effects into simulations without the need for expensive sampling over solvent degrees of freedom. The multipole moment expansion (MPE) model, while based on ideas initially put forward almost 100
Markus Sinstein, Christoph Scheurer, Sebastian Matera, Volker Blum, Karsten Reuter, Harald Oberhofer   +5 more
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Theoretical study of tautomers and photoisomers of avobenzone by DFT methods

Journal of Molecular Modeling, 2015
Organic ultraviolet (UV) filters such as cinnamates, benzophenones, p-aminobenzoic derivatives, and avobenzone (which have well-established and recognized UV-filtering efficacies) are employed in cosmetic/pharmaceutical products to minimize the harm caused by exposure of the skin to sunlight.
Gustavo H G, Trossini, Vinicius G, Maltarollo, Ricardo D'A, Garcia, Claudinéia A S O, Pinto, Maria V R, Velasco, Kathia M, Honorio, André R, Baby   +6 more
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A subspace based method for error correction with DFT codes

IEEE International Conference on Communications, 2003. ICC '03., 2004
A subspace based method for real error correction with low-pass DFT codes is proposed. The common roots of the eigen-polynomials of the syndrome covariance matrix associated with the zero eigenvalue gives the error locations. When the codevectors are quantized, the localization algorithm is modified so as to minimize the quantization noise effects. The
Gagan Rath, Christine Guillemot
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A method of using Simpson's rule in the DFT

IEEE Transactions on Acoustics, Speech, and Signal Processing, 1981
The method of taking a 2N-point DFT by means of an N-point DFT is modified such that Simpson's rule replaces the trapezoidal rule in the approximation to the Fourier integral. The Simpson's rule version is compared to the trapezoidal rule version on the basis of equal upper bounds on truncation error, and it is shown that Simpson's rule has the ...
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