The use of atomic weapons at the end of World War 2 fostered fears about their potential use during the Cold War years.
Interrupts and signals are low-level mechanisms that can alter the flow of control in a way similar to a subroutine, but usually occur as a response to some external stimulus or event (that can occur asynchronously), rather than execution of an 'in-line' control flow statement.
Control is a Continuous Process: Controlling is not the last function of management but it is a continuous process. Control is not a one-time activity, but a continuous process. The process of setting the standards needs constant analysis and revision depending upon external forces, plans, and internal performance.