Defense Health Agency. The Defense Health Agency (DHA) is a joint, integrated Combat Support Agency that enables the U.S Army, U.S Navy, and U.S Air Force medical services to provide a medically ready force and ready medical force to Combatant Commands in both peacetime and wartime.
Definition of preemption. 1a : the right of purchasing before others; especially : one given by the government to the actual settler upon a tract of public landb : the purchase of something under this right.
You may improve this article, discuss the issue on the talk page, or create a new article, as appropriate. (December 2010) Traffic signal preemption (also called traffic signal prioritization) is a type of system that allows the normal operation of traffic lights to be preempted.