8,166 research outputs found
Cause of Chirality Consensus
Biological macromolecules, proteins and nucleic acids are composed
exclusively of chirally pure monomers. The chirality consensus appears vital
for life and it has even been considered as a prerequisite of life. However the
primary cause for the ubiquitous handedness has remained obscure. We propose
that the chirality consensus is a kinetic consequence that follows from the
principle of increasing entropy, i.e. the 2nd law of thermodynamics. Entropy
increases when an open system evolves by decreasing gradients in free energy
with more and more efficient mechanisms of energy transduction. The rate of
entropy increase is the universal fitness criterion of natural selection that
favors diverse functional molecules and drives the system to the chirality
consensus to attain and maintain high-entropy non-equilibrium states.Comment: 8 pages, 2 figure
On the Performance of Multiple Antenna Cooperative Spectrum Sharing Protocol under Nakagami-m Fading
In a cooperative spectrum sharing (CSS) protocol, two wireless systems
operate over the same frequency band albeit with different priorities. The
secondary (or cognitive) system which has a lower priority, helps the higher
priority primary system to achieve its target rate by acting as a relay and
allocating a fraction of its power to forward the primary signal. The secondary
system in return is benefited by transmitting its own data on primary system's
spectrum. In this paper, we have analyzed the performance of multiple antenna
cooperative spectrum sharing protocol under Nakagami-m Fading. Closed form
expressions for outage probability have been obtained by varying the parameters
m and Omega of the Nakagami-m fading channels. Apart from above, we have shown
the impact of power allocation factor (alpha) and parameter m on the region of
secondary spectrum access, conventionally defined as critical radius for the
secondary system. A comparison between theoretical and simulated results is
also presented to corroborate the theoretical results obtained in this paperComment: Accepted in the proceedings of IEEE PIMRC 2015 Hong Kong, Chin
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