Origin [edit]. The systematic use of belt color to denote the rank was first used by Kano Jigoro, the founder of judo, who first devised the colored belt system using obi (sash), and awarded the first black belts to denote a Dan rank in the 1880s. Previously, Japanese Koryu instructors tended to provide certificates.
Everything for a safe and comfortable trip. Air safety is the theory, investigation, analysis, and categorization of flight failures (aircraft incidents and accidents), and the prevention of such failures through regulation, education and training.
Air gap (networking) An air gap, air wall or air gapping is a network security measure employed on one or more computers to ensure that a secure computer network is physically isolated from unsecured networks, such as the public Internet or an unsecured local area network.