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.
USAA is a four-letter acronym that stands for a wide variety of organizations and at least one act of Congress: 1  USAA United States Apnea Association. 2  USAA United Scenic Artists of America. 3  USAA United Services Automobile Association.  USAA United Sports Athletic 1  Association. USAA United States Achievement Academy.