Abstract: Provided herein is a unit cell for a phased array antenna. The unit cell can include a base plate and a shell. The shell can include a plurality of spectrum element cavities, with each spectrum element cavity comprising a post. An inner surface of each of the spectrum element cavities can be coated with a conductive material such that the spectrum element cavities form a signal ear and a ground ear of the unit cell. The base plate can be configured to provide a path to ground and include a plurality of holes. The shell can be aligned with the base plate such that the post of each signal ear of each spectrum element cavity is aligned with one of the holes of the base plate.

Abstract: In a distributed data access system in which a plurality of computers maintain and provide access to a database of stock exchange information, 1-for-N redundancy is provided by operating one computer in a standby mode, while the other computers operate online. Each online computer provides access to the database to a predefined set of a geographically broad plurality of users. The set of users for any online computer is defined by user connectivity data structures that define connectivity between the user set and the computer. When a failure is detected in any one of the computers, the user connectivity data structures of that computer are provided to the standby computer, which then assumes all operations of the failed computer. An arbitrator computer facility observes the health and determines the status of each of the computers, including the standby computer, and controls the transfer of online status from a failed computer to the standby computer.

Abstract: In a distributed data access system in which a plurality of computers maintain and provide access to a database of stock exchange information, 1-for-N redundancy is provided by operating one computer in a standby mode, while the other computers operate online. Each on-line computer provides access to the database to a predefined set of a geographically broad plurality of users. The set of users for any on-line computer is defined by user connectivity data structures that define connectivity between the user set and the computer. When a failure is detected in any one of the computers, the user connectivity data structures of that computer are provided to the standby computer, which then assumes all operations of the failed computer. An arbitrator computer facility observes the health and determines the status of each of the computers, including the standby computer, and controls the transfer of online status from a failed computer to the standby computer.