We investigate the power spectrum of velocity fluctuations in the universe starting from four different measures of velocity: the power spectrum of velocity fluctuations from peculiar velocities of galaxies; the rms peculiar velocity of galaxy clusters; the power spectrum of velocity fluctuations from the power spectrum of density fluctuations in the galaxy distribution; and the bulk velocity f...

In this paper we present a detailed simulation method to estimate the accuracy of Doppler power spectrum and mean blood velocity, using real CW Doppler transducers with twin-crystal arrangement. The method is based on dividing the sample volume into small cells using the statistics of the total power of Doppler spectrum with the same Doppler shift frequency, and from total power, which predicts...

We derive the energy spectrum in wave-number-frequency space for turbulent flows based on Kraichnan's idealized random sweeping hypothesis with additional mean flow, which yields the instantaneous energy spectrum multiplied by a Gaussian frequency distribution. The model spectrum has two adjustable parameters, the mean flow velocity and the sweeping velocity, and has the property that the power...

Cognitive Radio (CR) networks enable dynamic spectrum access and can significantly improve spectral efficiency. Cooperative Spectrum Sensing (CSS) exploits the spatial diversity between CR users to increase sensing accuracy. However, in a realistic scenario, the trustworthy of CSS is vulnerable to Spectrum Sensing Data Falsification (SSDF) attack. In an SSDF attack, some malicious CR users deli...

velocity analysis is one of the most important step in seismic data processing. it affects not only many processing steps directly and indirectly, but also is known as a primary interpretation of the data. however, it can also be assumed as one of the most time consuming processing step. the conventional velocity analysis method measures the energy amplitude along hyperbolic trajectories within...

Image-based servozng systems are often used to track moving targets and their underlying control architecture is a regulation of the image. This regulation is a function of rigid camera-to-target geometric constraints. Satisfying such constraints requires that the robot motors have suficient velocity bandwidths, and oflen these bandwidths are limited. This paper lays down the foundation for a p...