Investigation of multilevel amplitude modulation for a dual-wavelength free-space optical communications system using realistic channel estimation and minimum mean-squared-error linear equalization.

Fog is a highly dispersive medium at optical wavelengths, and the received pulse waveform may suffer significant distortion. Thus it is desirable to have the impulse response of the propagation channel to recover data transmitted through fog. The fog particle density and the particle size distribution both strongly influence the channel impulse response, yet it is difficult to estimate these parameters.

Numerical studies on time-domain responses of on-off-keyed modulated optical signals through a dense fog.

We present a numerical technique to simulate the propagation characteristics of an on-off-keyed modulated optical signal through fog. The on-off-keyed modulated light (a square wave) is decomposed into a finite number of harmonic components, and a numerical solution for the vector radiative transfer equation is obtained for each harmonic that corresponds to the modulation frequency. With this method we study the distortion and the pulse spread in the received signal due to attenuation and scattering.

The effect of volume currents due to myocardial anisotropy on body surface potentials.

Changes in anterior and posterior body surface potential maps (BSPMs) due to myocardial anisotropy were examined using a highly heterogeneous finite element model of an adult male subject constructed from segmented magnetic resonance images. A total of 23 different tissue types were identified in the whole torso. The myocardial fibre orientations in the human heart wall were mapped from the fibre orientations of a canine heart which are available in the literature using deformable mapping techniques.