Abstract: This disclosure describes an on-board oxygen generating system (OBOGS) using open loop control. An example OBOGS includes a concentrator comprising at least two beds and a controller. Each bed has a valve to pneumatically couple the bed between a supply gas source and a vent; The controller receives at least one input signal from at least one sensor aboard an aircraft, and determines a predicted oxygen concentration output from the at least two beds into the based on the received input signals. The controller controls the valves of the at least two beds based on the determined predicted oxygen concentration to adjust charge/vent ratios of the at least two beds.

Abstract: An authentication method implemented on a server for authenticating a user device in a network comprising user devices and a server associated with a resource to be accessed. The server is configured to receive a request for access to a resource from a first user device and identify an entity to be authenticated from the request. A rule information set specifying how to form a one-time-passcode from a random code is defined and the random code is provided to a first device associated with the identified entity. A rule information set is provided to a second device associated with the identified entity and a one-time-passcode from the second device generated from the random code using at least one rule information set and received at the server.