Abstract: The present invention discloses a method, apparatus, and article of manufacture for monitoring performance of a parallel database in a computer. In accordance with the present invention, the parallel database is stored on a data storage device in the computer. Groups of database nodes are identified. Collection time periods for collecting performance statistics from the identified group of database nodes are determined. Performance statistics are periodically collected from a subset of each identified group of nodes during the collection time periods. The collected performance statistics are stored in a memory connected to the computer and re-used when collecting performance statistics from one or more groups of database nodes in a succeeding collection time period.

Abstract: A Residual Time Stamp (RTS) technique provides a method and apparatus for recovering the timing signal of a constant bit rate input service signal at the destination node of a synchronous ATM telecommunication network. At the source node, a free-running P-bit counter counts cycles in a common network clock. At the end of every RTS period formed by N service clock cycles, the current count of the P-bit counter, defined as the RTS, is transmitted in the ATM adaptation layer. Since the absolute number of network clock cycles likely to fall within an RTS period will fall within a range determined by N, the frequencies of the network and service clocks, and the tolerance of the service clock, P is chosen so that the 2.sup.P possible counts, rather than representing the absolute number of network clock cycles an RTS period, provide sufficient information for unambiguously representing the number of network clock cycles within that predetermined range.

Abstract: A sychronous frequency encoding technique (SFET) provides method and apparatus for recovering the timing of an isochronous source node input service signal at the destination node of a synchronous ATM telecommunication network despite cell jitter which arises from the broadband multiplexing and switching delays in the network. A source node control clock is employed which is of greater frequency than that of the service signal and as a result a data under-flow condition occurs in the cell assembly process at a rate that is a function of the difference between such clock frequencies. Regular cell transmission is inhibited for a period at each under-flow occurrence and this pseudo-"stuffed cell" gap is signaled by setting a flag bit carried by an ensuing transmitted cell.

Abstract: A survivable ring network is disclosed that can withstand a cut link or failed node, without the need for a central controller or protection switching among links. The disclosed invention comprises two rings carrying identical multiplexed node-to-node communications in opposite directions. When a system error is detected in a downstream node, error signals are inserted in all subrate channels. Each subrate channel receiver receives identical communications from each ring. If one subrate channel has an error signal, the receiver selects the alternate channel.

Abstract: A method of structuring vectorized data obtained by scanning a drawing or other document comprising the steps of displaying on a computer controlled display screen a template image comprising template lines and nodes corresponding to the acquired image data and selecting portions of the acquired image data to be designated for inclusion in a restructured image data set by using a screen cursor to select the corresponding template lines displayed on the screen. Inclusion designations are subsequently and selectively removed as desired from portions of the acquired image data from the structured data set by using the cursor to select the corresponding lines and nodes on the screen. When the desired portions of the acquired data set are selectively designated for inclusion in the restructured data set, all remaining designated data is copied into the restructured image data.

Abstract: A Residual Time Stamp (RTS) technique provides a method and apparatus for recovering the timing signal of a constant bit rate input service signal at the destination node of a synchronous ATM telecommunication network. At the source node, a free-running P-bit counter counts cycles in a common network clock. At the end of every RTS period formed by N service clock cycles, the current count of the P-bit counter, defined as the RTS, is transmitted in the ATM adaptation layer. Since the absolute number of network clock cycles likely to fall within an RTS period will fall within a range determined by N, the frequencies of the network and service clocks, and the tolerance of the service clock, P is chosen so that the 2.sub.P possible counts, rather than representing the absolute number of network clock cycles an RTS period, provide sufficient information for unambiguously representing the number of network clock cycles within that predetermined range.