Vibro-acoustic analysis at high frequencies is challenging due to a large sensitivity spatial variations and short acoustical wavelengths, rendering deterministic methods expensive. At these frequencies, the wave field usually assumed diffuse. A realization of diffuse can be obtained considering that mode shapes system are Gaussian random fields, its squared eigenfrequency spacings distribution...

seismic waves travelling through inelastic media are attenuated by the conversion of elastic energy into heat. upon being attenuated, the travelling wave changes: amplitude is reduced, travelling waveform is modified due to high-frequency content absorption, and phase is delayed. attenuation is usually quantified through the quality factor q: the ratio between the energy stored and lost in each...

in this paper, a new algorithm for system identification based on frequency response is presented. in this method, given a set of magnitudes and phases of the system transfer function in a set of discrete frequencies, a system of linear equations is derived which has a unique and exact solution for the coefficients of the transfer function provided that the data is noise-free and the degrees of...

power transformers are key components in electrical power supplies and their failure could cause severe consequences on continuity of service and also generates substantial costs. identifying problems at an early stage, before catastrophic failure occurs, is a great benefit for reliable operation of power transformers. frequency response analysis (fra) is a new, well-known and powerful diagnost...

Cyclic averaging, as a method for reducing the leakage ermr in the estimatian of frequency response functions, is a simple and effective method that can be implemented in any data acquisit ion system. With the widespread availability of multikbamel data acqtisition systems, cyclic averaging may be the easiest approach to minimizing the huncation effect, known as leakage, that DccllIs when time ...

introduction: prior studies comparing hemodynamic response function (hrf) in the young and elderly adults based on fmri data have reported inconsistent findings for brain vision and motor regions in healthy aging. it is shown that the averaging method employed in all previous works has caused this inconsistency. the averaging is so sensitive to outliers and noise. however, fmri data are obscure...