1 Decoherence-free subspaces, subspace of a system's Hilbert space where the system is decoupled from the environment.  Dynamic Frequency Selection, part of the IEEE 802.11h wireless standard.
The American Psychological Association (APA) is a scientific and professional organization that represents psychologists in the United States.
From Wikipedia, the free encyclopedia. The American Fraternal Alliance (AFA) is an umbrella group of fraternal orders in the United States. It was founded as the National Fraternal Congress of America in 1913, in Chicago and adopted its current name in 2011.