Space-time correlations or Eulerian two-point two-time correlations of fluctuating velocities are analytically and numerically investigated in turbulent shear flows. An elliptic model for the space-time correlations in the inertial range is developed from the similarity assumptions on the isocorrelation contours: they share a uniform preference direction and a constant aspect ratio. The similar...

We present slitless spectra of the Narrow Line Region (NLR) in NGC 4151 from the Space Telescope Imaging Spectrograph (STIS) on HST, and investigate the kinematics and physical conditions of the emission line clouds in this region. Using medium resolution (∼ 0.5 Å) slitless spectra at two roll angles and narrow band undispersed images, we have mapped the NLR velocity field from 1.2 kpc to withi...

The introduction of color-coded duplex ultrasonography has improved the ease of performing ultrasound investigations of the vertebral arteries. So far, normal values of flow velocities have been reported only for the intertransverse region of the vertebral artery (V2 segments). Atherosclerotic disease at the origin of the vertebral arteries (V0 segment) is frequent and is one of the risk factor...

Velocity information is not only important for determining velocities and trajectories of objects but also important as a cue for image segmentation. It may be used to link adjacent but visually dissimilar surfaces or to divide surfaces not easily separable by static criteria alone[l]. A straightforward approach to obtaining velocity information is to find and track prominent features by a matc...

Velocity discrimination thresholds were determined for 1 c/deg drifting gratings when uncertainty about the reference velocity was introduced by interleaving stimuli with different reference velocities from trial to trial. When drifting gratings with reference velocities spanning 4 octaves (1-16 deg/sec) were mixed randomly within a series of trials, the velocity discrimination threshold for a ...

High-resolution spectra for 24 SMC and Galactic B-type supergiants have been analysed to estimate the contributions of both macroturbulence and rotation to the broadening of their metal lines. Two different methodologies are considered, viz. goodness-of-fit comparisons between observed and theoretical line profiles and identifying zeros in the Fourier transforms of the observed profiles. The ad...

The aim of the study was to evaluate kinematic and muscular activation differences amongst different age groups of soccer players. Thirty male youth soccer players were divided into 3 groups according to their age (age 12-13; age 14-15; age 16-17). There were significant differences in ball velocities and isokinetic strength values amongst groups. Angular and linear velocities of hip, knee, ank...

The NGSIM trajectory data sets provide longitudinal and lateral positional information for all vehicles in certain spatiotemporal regions. Velocity and acceleration information cannot be extracted directly since the noise in the NGSIM positional information is greatly increased by the necessary numerical differentiations. We propose a smoothing algorithm for positions, velocities and accelerati...