In this paper, we present a numerical analysis of the effect of random noises contained in interferograms of a vibrating object. We theoretically investigated the case where several Bessel-function arguments are used ...
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In this paper, we present a numerical analysis of the effect of random noises contained in interferograms of a vibrating object. We theoretically investigated the case where several Bessel-function arguments are used to determine object-vibration phasors. The value of each argument can be calculated from holographic interferograms with phase-modulation phasors of the same magnitude but of different phases. The root-mean-square (rms) error values of object-vibration amplitudes are different for the two algorithms, called synchronous and sum algorithms. At smaller object-vibration amplitudes, values determined by the former have higher accuracies, while for larger amplitudes, those determined by the latter have higher accuracies. Averaging these values by weights, which are the square reciprocals of the respective rms errors gives higher accuracies. The rms error values depend on the phase-modulation magnitude. These values in the cases of the former and latter algorithms are minimum at phase-modulation magnitudes of 0.640 pi and 0, respectively.
A recursive equation for computing higher-order derivatives of the elementary symmetric functions in the Rasch model is proposed. The formula is conceptually simple and relatively more efficient than the sum algorithm...
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A recursive equation for computing higher-order derivatives of the elementary symmetric functions in the Rasch model is proposed. The formula is conceptually simple and relatively more efficient than the sum algorithm (Gustafsson, 1980). A simulation study indicated that the proposed formula has a small loss in accuracy, compared to the sum algorithm, for computing higher-order derivatives when tests contained 60 items or less.
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