Private was an experimental rocket developed by the California Institute of Technology on behalf of the United States Army. Tested in two different configurations, it provided the proof of concept that a fin-stabilised ballistic missile was technologically feasible, and led to the development of the Corporal ballistic missile.
Private A was an unguided, fin-stabilised ballistic rocket; it consisted of a JATO unit equipped with cruciform tail fins, and a set of four T22 booster rockets that were jettisoned after launch. This made Private A the first multistage rocket to be flown in the United States.
In computer science, information hiding is the principle of segregation of the design decisions in a computer program that are most likely to change, thus protecting other parts of the program from extensive modification if the design decision is changed. The protection involves providing a stable interface which protects the remainder of the program from the implementation (the details that are most likely to change).
Written another way, information hiding is the ability to prevent certain aspects of a class or software component from being accessible to its clients, using either programming language features (like private variables) or an explicit exporting policy.
The term encapsulation is often used interchangeably with information hiding. Not all agree on the distinctions between the two though; one may think of information hiding as being the principle and encapsulation being the technique. A software module hides information by encapsulating the information into a module or other construct which presents an interface.
Aircraft camouflage is the use of camouflage, typically in the form of light and color patterns, applied to military aircraft to make them more difficult to see on the ground, in the air, or to make their speed, distance or attitude harder to determine. Military camouflage is highly dependent upon environmental conditions and is primarily effective against human observers, though some electronic visual acquisition systems can also be confused. It does not hinder radar location or heat-seeking electronics although the paints used may contain substances that can.
Camouflage colours and patterns are subject to considerable experimentation and theorizing, and most countries have explicit specifications as to their application that are sufficiently unique to make it possible to determine the intended operator in many cases even when no national insignia is visible. The colours and patterns have changed over time, both as new theories were tried, and as operational requirements changed. During and after World War II, the Yehudi lights project explored counter-illumination camouflage using lamps to increase the brightness of the aircraft to match the background. Recent experiments have looked at the use of light-emitting active camouflage systems which allow the colours and patterns to be changed to match the background.