As the Chinese national fish, large yellow croaker (Pseudosciaena crocea) can generate intermittent sounds. In this study, the acoustic characteristics of the sound signals recorded from three groups of net-cage-cultured large yellow croaker at different ages (7-8-month old, 13-15-month old, and 3-years old) were investigated. The exponential oscillation function derived from the speech signal ...

The effect of a continuous-wave (cw) laser based anemometer's probe volume on the measurement of wind turbulence is studied in this paper. Wind speed time series acquired by both a remote sensing cw laser anemometer, whose line-of-sight was aligned with the wind direction, and by a reference sensor (sonic anemometer) located in the same direction, were used. The spectral transfer function, whic...

In this paper, a novel technique for the design of two-channel Quadrature Mirror Filter (QMF) banks with linear phase in frequency domain is presented. To satisfy the exact reconstruction condition of the filter bank, low-pass prototype filter response in pass-band, transition band and stop band is optimized using unconstrained indirect update optimization method. The objective function is form...

in exploration seismology quality factor is widely used as a seismic attribute to identify anomalies related to attenuation, especially those caused by hydrocarbon. previous studies have indicated that seismic energy loss known as attenuation is greater for high frequency components of seismic data compared to the low frequency components. here the continuous wavelet transform is used to study ...

where P is the transmitted power, τ is the integration time, Gt and Gr are the transmit and receive antenna gains, λ1 and λ2 are the longest and shortest wave lengths respectively, σ is the target radar cross section, R is the target range, k is Boltzmanns constant, T is the effective receiver noise temperature and B is the receiver bandwidth. In the case of GPR, the signal attenuation in the g...

For detecting water pipeline leakage signals, in the past people preferred to use sensors obtain signal and then various means methods remove noise increase positioning accuracy. However, as is generated, it spreads along wrapped soil. In this process, will change significantly, eventually becoming very different from original signal. As such, detection accuracy decline, distance becomes longer...

Based on the forward scattering amplitude function for sand particle under the Rayleigh approximation, the calculation models of microwave attenuation and phase shift due to sand and dust particles is given in terms of lognormal size distribution. The model shows that attenuation and phase shift are found to be dependent on visibility, frequency and complex dielectric constant. Obtained results...

Abstract In this paper, a linear distribution model, double exponential model and hyperbolic number are developed, the effect of dust particle size on its attenuation coefficient is considered. On basis, transmission characteristics electromagnetic waves in dusty plasma under different electron density models investigated. The coefficients derived detail using analytical methods, effects wave f...

Attenuation over distance in natural habitat is often difficult to predict when measured without respect to sound frequency. The physical-acoustic structure of Florida scrub habitat is described and both attenuation and reliability of attenuation are measured as a function of sound frequency, over several distances, speaker elevations, and microphone elevations. The spatial context of sound pro...