An electronic method of control that has been known since the early thirties is that of the phase-lock-loop technique. In this method the phase angle of a periodic signal whose frequency corresponds to the value of the quantity to be controlled is continuously compared with the phase angle of an applied signal whose frequency represents the specified value. A change in the phase difference betw...

Detecting and estimating the velocity of slowly moving targets from a moving platform is difficult due to the Doppler broadening of the ground clutter. The latest MTI (moving target indicator) technique employs STAP (spacetime adaptive processing) to reduce the clutter's signal and thus, is able to detect the target's speed [ 11. This technique has proven to be very effective for detecting high...

In the long-baseline laser interferometers for measuring gravitational waves that are now under construction, understanding the dynamical response to small distortions such as angular alignment fluctuations presents a unique challenge. These interferometers comprise multiple coupled optical resonators with light storage times approaching 100 m. We present a basic formalism to calculate the freq...

We study the spin-up of the accreting neutron stars with a realistic hyperon-softened equation of state. Using precise 2-D calculations we study the evolutionary tracks of accreting neutron stars in the frequency baryon-mass and angular-momentum frequency plane. In contrast to the case of spinning-down solitary radiopulsars, where a strong back-bending behavior has been observed, we do not see ...

In this Letter, we demonstrate quantitative phase imaging of biological samples, such as human red blood cells (RBCs) and onion cells using narrow temporal frequency and wide angular frequency spectrum light source. This type of light source was synthesized by the combined effect of spatial, angular, and temporal diversity of speckle reduction technique. The importance of using low spatial and ...

Previous reports have shown that the variance in ultrasound attenuation measurements is reduced when spatial and frequency compounding were applied in data acquisition and analysis. This paper investigates factors affecting the efficiency of compound attenuation imaging methods. A theoretical expression is derived that predicts the correlation between attenuation versus frequency slope (beta) e...

Bearing failure is one of the foremost causes of breakdowns in rotating machinery and such failure can be catastrophic, resulting in costly downtime. One of the key issues in bearing prognostics is to detect the defect at its incipient stage and alert the operator before it develops into a catastrophic failure. Signal de-noising and extraction of the weak signature are crucial to bearing progno...