The authors extend the numerical annealing algorithm framework presented by S. Kirkpatrick et al. to the case of continuous multidimensional parameter space. The design an efficient parameter inverse simulated anneali...
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ISBN:
(纸本)0780305825
The authors extend the numerical annealing algorithm framework presented by S. Kirkpatrick et al. to the case of continuous multidimensional parameter space. The design an efficient parameter inverse simulated annealing (PI-SA) algorithm, and obtain some important theoretical results on continuous annealing algorithm design. They apply the PI-SA optimization algorithm to fault diagnosis of analog circuits with tolerance. A software package for automatic diagnosis has been developed and applied to fault isolation of the electronic equipment of the remotely piloted vehicles. The diagnosis results obtained with the software package both ground simulation and in flight testing are satisfactory.
Aiming to determine the geometric and acoustic parameters of inhomogeneous multi-layer coatings, an ultrasonic pressure reflection coefficient amplitude spectrum (URCAS) is derived using a material-oriented regulariza...
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Aiming to determine the geometric and acoustic parameters of inhomogeneous multi-layer coatings, an ultrasonic pressure reflection coefficient amplitude spectrum (URCAS) is derived using a material-oriented regularization scheme, when wave propagates perpendicularly to the coating surface. Based on the derived theoretical URCAS, a new objective function combining least-squares and cross-correlation algorithm is developed to simultaneously identify the thickness, sound velocity, density, attenuation coefficient amplitude, and attenuation coefficient power-law of the multi-layer coating. Genetic algorithm with the constraint of total multi-layer coating thickness being known is presented to optimize the nonlinear objective function for obtaining global optimal solution. Ultrasonic experiments were implemented on a dual-layer coating specimen with coating1/coating2/substrate structure using a flat immersion transducer with a central frequency of 15 MHz. The inversed thicknesses, sound velocities, and densities of the dual-layer coating were in good agreement with those measured through other methods, with less than 8.1% errors. The inversed attenuation coefficients of the coating 1 and coating 2 were alpha(f) = 1.02e(-2) x f(1.93) and alpha(f) = 4.62e(-3) x f(1.97), respectively. The upper bounds of the relative errors (+)r of inverted parameters were all less than 0.061. The proposed ultrasonic inversion method could be used to quantitatively characterize the surface integrity of inhomogeneous multi-layer coatings.
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