RESUMEN
At a time when the semiconductor industry is facing major difficulties in maintaining sluggish growth, new high-level synthesis tools are repositioning FPGAs as a leading technology for hardware-based algorithm acceleration, in the face of CPUs based clusters. As they stand, however, these tools do not guarantee that a software engineer can use these technologies to their full potential without expertise in the underlying hardware. This particularity can be an obstacle to their democratization. When it comes to acoustic scattering (AS) and its various applications, there is a growing need for autonomous and integrated systems that can operate in real time with high accuracy. This is why we propose our methodology for accelerating algorithms on FPGAs. After presenting a high-level architecture model of this target, we detail various possible optimizations in OpenCL, to finally define a relevant exploration strategy for algorithm acceleration on FPGAs. Applied to various case studies, to characterize and identify an immersed metal tube in the frequency range between 0 and 46.8 kHz. We evaluate our methodology according to three main performance criteria: execution time, resource utilization and energy efficiency. The experimental results show that the proposed methodology is efficient and effective. Indeed, the computation times using the DE1 Soc FPGA and a modern CPU are about 3.5s and 74s respectively. In addition, the absolute error did not exceed 10-5.
RESUMEN
In this paper, recent studies of backscattered acoustic signals in thinner steel-polymer tubing structures have been presented. Reassigned smoothed pseudo Wigner-Ville (rspWV) analysis has been adopted in order to diminish the cross-term effect, and achieve high resolution spectral. Vibration modes, which are associated to the resonances of circumferential waves, have been determined by using the modal isolation plan representation. At normalized frequencies below 140, an appreciable influence from the polymer coating thickness on the A0+ and S0 modes has been noticed. Furthermore, the trajectory of the A0- wave has been modified in the normalized frequency band 40-42. Group velocity curves of the A0- wave have, then, been graphically illustrated. The findings have shown a particular curvature change at reduced frequency 41 in the case of an immersed two-layer tube in water. Studies of acoustic backscattering involving steel-polymer tubing structures have confirmed the significant coupling of A0+ and S0 waves. Besides, the disappearance of the A0+ resonance trajectory has been observed; which is a very important phenomenon to understand.
RESUMEN
The present paper studies the acoustic signal backscattered by an air-filled coppersolid polymer two-layer cylindrical tube immersed in water. The work is done from the calculation of the backscattered pressure, an inverse Fourier Transform, which allows us to obtain an impulse signal. Smoothed pseudo WignerVille and Concentrated spectrogram representations have been chosen to analyze the scattering phenomenon. For reduced frequencies ranging from 0.1 to 200, the resonance trajectories and timefrequency images have shown the presence of the guided waves. The bifurcation of the A0 wave into the A0(-) and the A0(+) waves has also been observed. The authors provide the phase and the group velocities of guided waves and investigate the differences between curves. The findings are then compared with those obtained for the copper and the solid polymer one-layer cylindrical tubes. Group velocity values have also been extracted from smoothed pseudo WignerVille and Concentrated spectrogram timefrequency images. A good agreement with the theory has, therefore, been observed. The study of acoustic backscattering by a coppersolid polymer two-layer tube has revealed the interaction and the coupling of guided waves, specially the presence of a pseudo A1 wave; which is a very interesting, remarkable phenomenon.