Abstract: In a retention management scheme, an object, such as a document or folder, is provided with an expiration time in the form of a time stamp attribute. The identification of the security subject providing the expiration time is also an attribute of the object. When the expiration time occurs, the authorization of the security subject is checked. If the security subject lacks authority to delete the expiration time, then the object is maintained on the data processing system and the expiration time is ignored. If the security subject has the authority to delete at the expiration time, then the object is deleted.

Abstract: Access by a security subject to an object on a data processing system is automatically controlled in accordance with a time based schedule. In accordance with times contained in the schedule, an access control list of an object is modified by either adding, to invoke access, or deleting, to revoke access, a security subject. The schedule is made up of one or more requests for single access or cyclical accesses that are stored in a request queue. The request queue is periodically polled to determine if any requests qualify for further processing. A request is processed if the time for changing the status of the security subject on the access control list, as specified by the request, is either the same as or less than the current time of the data processing system. Processing the request modifies the access control list by either adding or deleting the security subject to or from the access control list.

Abstract: A method and system for creating and maintaining multiple document versions in a data processing system implemented library. Selected documents within a data processing system implemented library are uniquely identified as root documents and a version-root identifier for each successor version of a particular root document is established. Thereafter, a selected version-root identifier is automatically associated with each created successor version of a root document. Upon the creation of a successor version of a root document and a second predecessor document, the version-root identifier associated with the root document is automatically associated with the successor version and the second predecessor document. Upon the creation of a successor version base upon multiple non-root predecessor documents a particular non-root predecessor document is automatically selected as a root document and a version-root identifier is established and associated therewith.

Abstract: A method and system for controlling access by groups of users to multiple objects stored within a data processing system implemented library wherein each object has an access list associated therewith explicitly listing individual users permitted access to that object. A group identification is established which encompasses all users within the data processing system, a selected subset of users with the data processing system, or a single selected user and his or her designated affinity users or proxies. The group identification is then listed within an associated access list for a particular object and upon an attempted access of the particular object by a user not listed explicitly within the associated access list, a determination is made as to whether or not that user is listed within a group identification which is permitted access.

Abstract: Display for use on propeller driven aircraft comprised of a radially disposed row of lamps 12 embedded in the rear surface of a propeller 11. Measurements of flight data are made by conventional means and converted into digital signals (15 and 18). These digital signals are applied to graphic generators, 16 and 19, which control lamp drivers 13 which in turn control lamps 12 through slip rings 14. The lamps 12 are lit at appropriate times (determined by sync pulses 17) during each revolution of the propeller to cause the flight data in graphic form to appear to the pilot.