Abstract: A boomer for generating acoustic signals in a marine seismic survey has a frame towed by a survey vessel. A coil is mounted to the frame and a conductive plate is adjacent to the coil. A capacitor is mounted to the frame, and control electronics system delivers an electric charge stored in the capacitor to the coil. The invention obviates the need for heavy conductive cables between the survey vessel and the boomer in conventional systems where the capacitors are carried by the vessel, while maintaining the desirable acoustic properties of the boomer.

Abstract: A system and particular components are disclosed to measure the reaction time of a user from a signal to start an athletic activity to the start of that activity and the completion time from the start to the finish of that activity. A remote control device responsive to manual input initiates a start signal and a signal to direct that activity toward one or more sensor pads to a user and to a data processor. One or more floor pads sense the presence of the user and signal the user's non-presence to the data processor. One or more sensor pads positioned spacedly distant from the floor pads sense manual contact by the user and signal that event to the data processor. The data processor determines the reaction time and the completion time of an activity from the times of the received signals, annunciates these times in visually cognizable form and stores the data.

Abstract: An Integrity Server computer for economically protecting the data of a computer network's servers, and providing hot standby access to up-to-date copies of the data of a failed server. As the servers' files are created or modified, they are copied to the Integrity Server. When one of the servers fails, the Integrity Server fills in for the failed server, transparently providing the file service of the failed server to network clients. The invention provides novel methods for managing the data stored on the Integrity Server, so that the standby files are stored on low-cost media such as tape, but are quickly copied to disk when a protected server fails. The invention also provides methods for re-establishing connections between clients and servers, and communicating packets between network nodes, to allow the Integrity Server to stand-in for a failed server without requiring reconfiguration of the network clients.

Abstract: An electron beam welding machine incorporating a surface seal system which continuously seals the weld chamber located in an indexing table while such chamber is indexed beneath a seal plate carrying the surface seal material. As a result of the pressure differential involved, the seal surface also acts as a bearing surface as the wear plate on the indexing table moves in contact with the seal surface.