In this letter, the performance is compared for slowfrequency-hop and direct-sequence spread-spectrum packet communication systems of similar complexity with doubly selective fading channels characterized by several different multipath delay profiles and Doppler spreads. The delay profiles are chosen to reflect experimental measurements of mobile-radio channels, and the Doppler spreads are chos...

Wave propagation in a photosensitive, subexcitable Belousov-Zhabotinsky medium is made possible by periodic modulation of a homogeneous illumination field. The propagation can be understood in terms of an interplay between the radial expansion of the wave and the motion of its free ends as the excitability varies periodically. This description leads to a simple kinematic analysis that provides ...

Astrocytes, a special type of glial cells, were considered to have just a supporting role in information processing in the brain. However, several recent studies have shown that they can be chemically stimulated by various neurotransmitters, such as ATP, and can generate Ca2+ and ATP waves, which can propagate over many cell lengths before being blocked. Although pathological conditions, such a...

The mechanism of vibration energy transfer in a vibrating fluidized bed (VFB) is reported in this paper. A series of sensors was employed to simultaneously detect pressure wave propagation signals at different positions at various heights in the fluidized bed. The mechanism of vibration energy transfer in an VFB is found by wave propagation. The pressure wave was produced from a vibrating base ...