Abstract: The present invention relates a communication terminal for the synchronization of audio and visual information within a communication system. Audio communication between the parties to a video conference is achieved by digitizing the speech and transmitting the same over a packet based data network. Each party to the conference can draw the attention of the other party to an object on the screen using a pointer controlled by, say, a mouse or ball. The co-ordinates of each parties' pointer are incorporated, via a multiplexer, into the data packets containing the digitized speech and transmitted to the other party's terminal thereby ensuring the synchronization the pointer information with the digitized speech.

Abstract: A system and method for performing variable speed scanning or browsing, wherein a user controls the playout speed of a movie, which does not require additional disk or network bandwidth resources. In a preferred embodiment, the method provides for scanning operations for an Motion Picture Experts Group (MPEG) video stream. The method satisfies the constraints of the MPEG decoder (in the users set-top box) and require a minimum of additional system resources. The embodiments of the present invention include (a) a storage method, (b1) a segment sampling method, (b2) a segment placement method, and (c) a playout method, where (b1) and (b2) are two alternatives for segment selection. Thus, two sets of solutions are provided to support variable speed scanning in a disk-array-based video server: One using (a), (b1) and (c), and the other using (a), (b2) and (c).

Abstract: A system and method for avoiding serialization on updating the modification time of files in a cluster system. In accordance with the method, the modification time field of a file can be accessed by multiple readers or multiple writers and each client in the cluster system can update their own copy of the modification time. Whenever a client requests to read the modification time, the copies of the modification time are reconciled. The copies of the modification times are also reconciled when a cache flush or synchronization operation forces such reconciliation. The present system and method supports the requirement (of certain operating systems such as UNIX) that an explicit user-issued command to set the modification time is accomplished by granting an exclusive-write mode for the modification field.

Abstract: The present invention provides a plug-in ground fault monitor module for a circuit breaker trip unit configured to operate with a plurality of different plug-in plug-in modules. The ground fault monitor module includes a memory which stores data representative of the its particular function. This memory is readable by the trip unit and enables the trip unit to automatically adapt to communicate monitored ground fault data to the ground fault module. The ground fault module also includes means for setting threshold levels for a ground fault alarm signal. The ground fault alarm signal is generated independently of ground fault alarms in the trip unit based on its internal thresholds. This signal can be used to control an external relay which operates a shunt trip mechanism or an external alarm. The trip unit includes a processor and programming which permits a bi-directional flow of data between the units, such as display data and control data.

Abstract: A system and method of supporting pause-resume in a video-on-demand service of a type which can accommodate multiple viewers sharing a common data stream is described. When a video server receives a performance request from one of the viewers for showing a particular video, it identifies and reserves a look-ahead stream. The look-ahead stream is another video stream which is scheduled to become available after a predetermined time period. When the video is commenced, a common data stream for the video is concurrently transmitted from the video server to reception equipment at the viewers' locations. Transmission of the common data stream causes the particular video to be performed on the viewers' reception equipment. When the video server receives a pause request and then a subsequent resume request from one of the viewers, it transmits the video via the look ahead stream instead of the common data stream.

Abstract: A locking apparatus for a multicomputer system. The lock apparatus is a two level system wherein local lock managers grant locks on a resource only after they have acquired an appropriate token from a rock control server which is the owner of the resource. The lock control server is passive and has all the control information for a resource it owns. When a local lock manager needs a token in a specified mode for a particular resource, it acquires the token from the lock control server. If there are no conflicting tokens, then the rock control server grants the token. However, if there are conflicting tokens, then the lock control server responds with a list of the local lock managers with conflicting tokens. The requesting lock manager then requests each of the local lock managers with conflicting tokens to give it up and to acknowledge when it has done so. When the acknowledgements have been received, the local lock manager requests the lock control server to update its table and grant the requested token.

Abstract: An integrated scheduling approach that provides VCR control functions to clients without always requiring a separate video stream for all clients. When a client invokes a resume, following a pause, the system uses a hierarchy of methods to handle the request. If an ongoing video stream is available such that the point at which the client is paused will be reached by that stream within a tolerable delay, the client is assigned to the ongoing stream. If no such stream is available, and the client request can not be served from a buffer, the system assigns the client to a reserve stream taken from a pool of reserved server capacity. If no reserved server capacity is available, the client is given priority for assignment to the next stream to become available.

Abstract: A system and method for processing a stream of video image data so as to create a video representation that multiplexes data corresponding to resolution or bitstream scales. This representation is such that the identity of the basic MacroBlock (MB) structure of the MPEG-1 ISO standard is preserved across all resolution and bitstream scales, e.g. by scaling across four levels of resolution. A MacroBlock is associated with a series of attributes which contribute to the amount of overhead data incorporated in an MPEG-1 compressed data stream, so that by preserving the MacroBlock identify across multiple resolutions and bitstream scales, these scales can share this overhead, thus requiring it to be included only once in the data stream. Preserving the MacroBlock identify also simplifies significantly the derivation of motion estimation vector data for all resolution scales other than the highest resolution.

Abstract: A system and method involving a statistical conditioning technique that improves the coding efficiency in compression systems which have unstable statistical properties by conditioning the probability estimate for a given model context on prior decisions for that context thus enlarging the conditioning decision set. Instead of extending the model context by increasing the range of prior decisions in the pixel neighborhood, each model context is expanded into a set of two contexts which are the actual coding contexts. For a given probability estimation model context, the selection of a coding context index is done on the basis of the previous coding decision (1 or 0) for that model context. Thus, if a model context is assigned an index A, the coding context would be assigned an index 2*A +D(A)', where D(A)' is the previous (immediately preceding) binary decision for model context A; the decision of which coding context to use turns on whether the model context was used most recently for coding a 1 or a 0.

Abstract: A remote tripping mechanism for use with a spring loaded safety switch. In a preferred embodiment, the mechanism is made up of two cams with a compression type trip spring anchored between them. The two cams are held in the "normal position" (the spring compressed) by a latch. In this position, the switch operates in the same manner as a conventional safety switch. A trip lever connected to a solenoid is positioned such that it is unobtrusive when the switch is turned ON and OFF. When the switch is in the ON position and power is applied to the solenoid, the trip lever unlatches the latch and the two cams separate. The first cam engages and lifts the bail, turning the switch OFF. The cams are reset by turning the handle to the OFF position. This compresses the trip spring and resets the latch.

Abstract: A plurality of queries (jobs) which consist of sets of tasks with precedence constraints between them are optimally scheduled in two stages of scheduling for processing on a parallel processing system. In a first stage of scheduling, multiple optimum schedules are created for each job, one optimum schedule for each possible number of processors which might be used to execute each job, and an estimated job execution time is determined for each of the optimum schedules created for each job, thereby producing a set of estimated job execution times for each job which are a function of the number of processors used for the job execution. Precedence constraints between tasks in each job are respected in creating all of these optimum schedules. Any known optimum scheduling method for parallel processing tasks that have precedence constraints among tasks may be used but a novel preferred method is also disclosed.

Abstract: The bandwidth of the data transfer among a main memory and snoopy caches is improved by solving the bus bottleneck in a multiprocessor system using a snoopy cache technique. Shared bus coupling is employed for an address/command bus requiring bus snoop whereas multiple data paths coupled by an interconnection network are used for the data bus not requiring bus snoop. The multiple data paths reflect the order of the snoopy operations on the order of data transfer such as to maintain data consistency among the caches.

Abstract: A two dimensional matrix of marks indicating match or mismatch of one or more search arguments with the value of data elements accessed from a field common with all records of a database file. The matrix of marks created after one pass through all the records of the file is searched for a specified pattern which identifies records where the data element values, as between successive records, have a certain sequence as specified by the search arguments.

Abstract: A self-parallelizing computer system and method asynchronously processes execution sequences of instructions in two modes of execution on a set of processing elements which communicate with each other. Each processing element is capable of decoding instructions, generating memory operand addresses, executing instructions and referencing and updating its own set of general purpose registers. These processing elements act in concert during the first mode of execution not only to execute the instructions in an execution sequence but also to partition an execution sequence into separate instruction subsequences. The separate instruction subsequences are stored along with additional information which will allow the stored subsequences to be correctly executed in parallel.

Abstract: A computer-utilizing security system and method involving a collection of personally selected strong-reaction sensory and/or historical multimedia-type cues in combination with a related set of structured information. The cue combination is submitted by one or more individuals to be authorized to access a secure environment, so that when a multimedia cue along with a set of queries contained in and regarding the related information are presented for gaining entry to the secured environment, an authorized individual may readily respond to the queries with correct reactions based on strong personal recall.

Abstract: A method and apparatus is disclosed for folding the execution of a multi-way branch or switch based upon an operand (e.g.,the block of instructions normally associated with a case statement) into a single instruction. This insulates branch prediction mechanisms from making incorrect predictions that are normally associated with a multi-way branch. A table saves the past history of multi-way branch execution. This table contains three fields: the starting address of a multi-way branch; a value of the operand used to execute that multi-way branch in the past; and the larger target address generated by that multi-way branch in the past when that particular operand value was used. In accordance with one embodiment of this invention, other branch prediction mechanisms (such as a Branch History Table or Decode History Table) are disabled from redirecting instruction fetching during execution of a multi-way branch in an instruction stream.

Abstract: An apparatus, embodied in an Intelligent Page Store, for providing concurrent and consistent access to a functionally separate transaction entity and a query entity to a shared database, while maintaining a single physical copy of most of the data. The Intelligent Page Store contains shared disk storage, and an intelligent versioning mechanism allows simultaneous access by the transaction entity and the query entity to the shared data. The transaction entity is presented the current data and the query entity is presented a recent and consistent version of the data. A single copy of all but recently updated pages is maintained by the Intelligent Page Store. The query and transaction entities operate independently of each other and are separately optimized.

Abstract: A method for increasing cache concurrency in a multiprocessor system. In a multiprocessor system having a plurality of processors each having a local cache in order to increase concurrency the directory entry for a line in local cache will be assigned an LCH bit for locally changed status. If the last cache to hold the line had made a change to it this bit will be set on. If not, the bit will be off and thereby allow the receiving or requesting cache to make change to the line without requiring a main storage castout.

Abstract: In a 3-D magnetic resonance flow imaging apparatus, the RF excitation field is applied so as to produce a spatial variation of the nuclear spin flip angle within the imaging volume. The spatial variation results in nuclear spins at the volume entrance plane experiencing a relatively small flip angle, and experiencing progressively larger flip angles as they progress into the volume.

Abstract: In an initial set up sequence, N pels of an original image are stored in N memory positions of an input buffer. The N pels are converted to M pels, which are stored in M memory positions of an output buffer, where M and N are integers larger than 0. In the case of N<M, an enlargement of the original image is made, and in the case of N>M, a reduction of the original image is made. An address counter pointing to an address of a memory position of the input buffer is initially reset to 0. An address counter pointing to an address of the memory position of the output buffer is also reset to 0. The values -N, M, and an initial sum value S (where S is integer satisfying -N.ltoreq.S<M) are initially stored in three registers, respectively. The initially stored sum value S is repeatedly updated to control the scaling up operations or the scaling down operations. There is a first device which determines or checks whether the sum value is negative, or not.