Under this category we introduce Avionics. Avionics covers a number of categories under aviation electronics, and it envelopes all electronic systems designed for use on an aircraft. This comprises communications, navigation and the display and management of multiple systems. It also comprises the literally hundreds of systems that are fitted to aircraft to meet numerous requirements.
Next we have embedded computers, which are used in special-purpose systems in which the computer is dedicated to the device or system it controls. Unlike general-purpose computers, e.g. personal computers, embedded computers perform pre-defined task(s), usually with very specific requirements, run with limited hardware resources: small or no keyboard, screen, and little memory stored in read-only memory or Flash memory chips rather than a disk drive.
Micro and millimeter waves by virtue of their frequency range being in the electromagnetic spectrum, have their special needs addressed by GaAs / GaN / SiGe chips. GaAs is a well used and well known compound semiconductor, it has been used in a multitude of applications and serves as a benchmark against which the performance of other compound semiconductors are measured. Silicon germanium (SiGe) is a semiconductor technology made for wireless applications. It offers the high-speed, high-frequency performance needed for wireless systems, and it provides the potential for integrating analog, RF, and digital functions on a single integrated circuit based on low-cost Si wafers.
System Functions are an extensive family of applications that include system and control-voltage supply monitors, trackers, margin controllers, sequencers, push button controllers and power monitors. All these devices improve management and converter functionality with a high degree of accuracy, integration and ease of configuration.
By Gernot Heiser, Open Kernel Labs Kerckhoffs' principle, formulated by a 19th century Dutch mathematician, is the accepted basis for strong security.It was originally formulated for crypto algorithms, where it stated that an encryption system must not depend on the security of the algorithms, only the keys.