Risk-Adaptable Access Control (RAdAC) This paper considers the impediments of traditional access control approaches to sharing of. information. It describes a concept for an access control model that emulates real world decision-. making, considering operational need and security risk as part of each access control decision, and.
Turbulence can occur in the lowest part of the troposphere during the daytime when heating of the sun causes convective mixing of the air. Once the airplane rises above this turbulent boundary layer, the air becomes smoother. But other processes can also cause these up- and down-drafts.
Turbulence is what nervous fliers fear the most when they board an aircraft. It is also the most common cause of injury to air passengers - in the US alone there are an estimated 58 injuries each year due to turbulence. Pilots will always keep their seatbelts fastened while seated on an aircraft and will usually advise you to do the same.