Abstract: The evaluation of parallel job schedulers hinges on two things: the use of appropriate metrics, and the use of appropriate workloads on which the scheduler can operate. We argue that the focus should be on on-line open systems, and propose that a standard workload should be used as a benchmark for schedulers. This benchmark will specify distributions of parallelism and runtime, as found by analyzing accounting traces, and also internal structures that create different speedup and synchronization characteristics. As for metrics, we present some problems with slowdown and bounded slowdown that have been proposed recently.

Abstract: A system and method for temporal synchronization of media streams in multimedia collaborative applications (i.e., a multi-user distributed applications used for interaction, both in the synchronous and asynchronous fashion among a group of users) in a wide-area distributed environment. The invention presents two abstractions; event streams and collaboration space, that together provide for coarse-grained temporal synchronization by using separate streams for different media and synchronizing the streams at the client location. VCR-like controls are also provided on groups of components in a collaborative application. The event stream provides many services such as replication, persistence, buffering, reading, and writing to archive. By implementing simple interfaces, existing collaborative applications, media players, and encoders become components that can be used to build complex multimedia collaborative applications. To efficiently implement a seeking function on a data component, the present invention introduces a framework for application-specific updates to a component state.

Abstract: A particular problem of controlled synchronization of nonlinear systems is considered. Minimum conditions for producing such synchronization are presented and it is shown that these conditions also provide the feedback passivity of the overall system. It is also demonstrated that the conditions of feedback passivity allow one to design an adaptive synchronizing control law which ensures global synchronization in the cases when the systems to be synchronized have different parameters. Additionally it is demonstrated that the approach presented for the design of synchronizing systems allows one to cope with external disturbances in order to protect the systems from loss of synchrony.

Abstract: An overview over the methods currently under investigation for the transmission of information hidden in a chaotic signal is given. First, the notion of synchronization is discussed, then the coupling of two systems to achieve synchronization is presented and then four methods to mix the information signal with a chaotic carrier are described. Finally, the problem to send several information bearing chaotic signals through the same communication channel is posed as a challenge.

Abstract: This paper treats the synchronization problem of two Lorenz systems in the presence of unknown system parameters. Based on the Lyapunov stability theory, an adaptive control law is derived such that the two Lorenz systems are to be synchronized. A robust adaptive control law is also presented to guarantee the robustness of the synchronization against a bounded disturbance. Simulation results are given to demonstrate the effectiveness and robustness of the proposed control schemes.

Abstract: In accordance with a method and apparatus for synchronizing information browsing among multiple systems, a bridgeport system (103) receives identifiers for data requests received in a first hardware system (102) and automatically transmits the identifier of the requested data to one or more additional hardware systems (104). Each of these one or more hardware systems (104) then retrieves the identified data, thereby keeping the data being provided in these hardware systems in synchronization.

Abstract: Synchronization is effected in a cellular telecommunications network (20) between a master timing unit (60) located at control node (30) of the network and a slave timing unit (STU) located either at the control node or a controlled node, e.g., base station (22), of the network. In accomplishing the synchronization, one of the master timing unit or the slave timing unit serves as an initiating timing unit for transmitting a synchronization analysis command message including a first parameter (t1) to the other of the timing units which serves as a responding timing unit. In response, the responding timing unit sends a synchronization analysis response message which includes at least second parameter (t2) and preferably a third parameter (t3) to the initiating timing unit. The initiating unit uses e.g. parameters extracted from the synchronization analysis response message to determine a synchronization adjustment value for the slave timing unit. When the master timing unit is the initiating timing unit, the master timing unit transmits the synchronization adjustment value in a synchronization updating command message to the slave timing unit.

Abstract: A method and system for reducing the number of conditional requests for network content to a server by maintaining state for selected URIs in a local cache indicative of a confidence level that the files are unchanged. When a request for content is received that corresponds to such a URI in the cache, a synchronization time is determined based on a confidence level for that URI. If the synchronization time is achieved, a conditional request is sent to the server, otherwise the URI data is returned from the cache to respond to the request. Synchronization intervals for such files may be increased as the likelihood that the item is unmodified increases. URIs may need to be of a certain content type and required to pass a confidence test before being selected for automatic synchronization.

Abstract: This paper presents and evaluates a specification-based methodology for testing concurrent programs. This methodology requires sequencing constraints, which specify restrictions on the allowed sequences of synchronization events. Sequencing constraints for a concurrent program can be derived from the program's formal or informal specification. Details of the proposed testing methodology based on the use of Constraints on Succeeding and Preceding Events (CSPE) are given. How to achieve coverage and detect violations of CSPE constraints for a concurrent program, according to deterministic and nondeterministic testing of this program, are described. A coverage criterion for CSPE-based testing is defined and analyzed. The results of empirical studies of CSPE-based testing for four concurrent problems are reported. These results indicate that the use of sequencing constraints for specification-based testing of concurrent programs is a promising approach.

Abstract: Using experimental and numerical systems, we show that it is possible to maintain excellent synchronization between a drive and a response system even when there is a large (50%) parameter mismatch between them, and they are coupled only through a scalar signal. By optimizing the coupling consistent with a stability constraint, we show that a consequence of the optimized coupling is that the synchronization is maintained even in the presence of bifurcations in the drive system, despite the condition that the response parameters are held constant.

Abstract: Synchronized execution is maintained by compute elements processing instruction streams in a computer system including the compute elements and a controller. Each compute element includes a clock that operates asynchronously with respect to clocks of the other compute elements. Each compute element processes instructions from an instruction stream and counts the instructions processed. Upon processing a quantum of instructions from the instruction stream, the compute element initiates a synchronization procedure and continues to process instructions from the instruction stream and to count instructions processed from the instruction stream. The compute element halts processing of instructions from the instruction stream after processing an unspecified number of instructions from the instruction stream in addition to the quantum of instructions. Upon halting processing, the compute element sends a synchronization request to the controller and waits for a synchronization reply.

Abstract: A digital subscriber line communication system does not require the use of a plain old telephone service (POTS) splitter in the resident's home. Digital signal processing is utilized to adapt to varying subscriber line conditions coming from POTS telephone equipment. The digital subscriber line modem includes a control circuit that utilizes a Reed-Solomon decoder and a synchronization error generator. The Reed-Solomon decoder provides a frame error signal, and the synchronization error generator responds to the frame error signal to generate a synchronization error signal. The synchronization error generator is configured as a leaking integrator to provide the synchronization error signal in response to a relatively large number of frame error signals occurring in a period of time. A resynchronization operation is performed in the modem in response to the synchronization error signal.

Abstract: A computing device has a database replica comprised of a plurality of records. A synchronization request is provided to a further computing device having a further database replica which is comprised of a further plurality of records. A version table maintains version numbers for each of the plurality of records. The version numbers each have a maximum size. The maximum size is selectable. The plurality of records may be synchronized with the further plurality of records based upon the version numbers.

Abstract: A computer implemented method for workflow synchronization is provided. The first step comprises initializing the execution of a plurality of workflows. The next step is providing synchronization logic in at least one of the plurality of workflows. In the third step the execution of a workflow is paused until the synchronization logic is complete. In the final step the execution of the plurality of workflows continues.

Abstract: A multi-level correlation technique and apparatus for detecting symbol and data frame synchronization in high noise and multi-path environments, wherein received signals are correlated with known pseudorandom noise (PN) or other known codes at the base level and the base level correlation results are in turn correlated with PN or other known codes at the next higher level, such that the top level of correlation includes all lower levels of encoding in the complete synchronization pattern. In a two level implementation, the base level codes define symbols while the top level code defines the synchronization pattern in terms of the base level symbols. Correlation hardware is minimized while processing gain is maximized for enhancing low signal to noise levels over a long synchronization pattern. Additionally, precise ranging is facilitated because the top level correlation result covers the entire synchronization pattern.

Abstract: A code generating system generates, from code in a program, native code that is executable by a computer system. The code generating system may be included in a just-in-time compiler used to generate native code that is executable by a computer system, from a program in Java Byte Code form, and specifically generates, in response to Java Byte Code representative of a synchronization statement that synchronizes access by multiple threads of execution to at least one variable contained in the Java Byte code, one or more native code instructions that implements a wait-free synchronization methodology to synchronization access to the at least one variable. Since the instructions which implement the wait-free synchronization methodology do not require calls to the operating system, they can generally be processed more rapidly than other synchronization techniques which do require operating system calls.

Abstract: This paper shows how the canonical implementation [1] of the Singleton pattern does not work correctly in the presence of preemptive multi-tasking or true parallelism. To solve this problem, we present the Double-Checked Locking optimization pattern. This pattern is useful for reducing contention and synchronization overhead whenever “critical sections” of code should be executed just once. In addition, Double-Checked Locking illustrates how changes in underlying forces (i.e., adding multi-threading and parallelism to the common Singleton use-case) can impact the form and content of patterns used to develop concurrent software.

Abstract: A method for creating and updating user accounts at a central server that provides for establishment and synchronization of associated user accounts at a heterogeneous network of managed servers based on the user account information of the central server. This enables the network to consist of a heterogeneous set of servers that are executing with the same operating system or subsystem as the central server, and servers that are executing with a different operating system or subsystem as the central server. The updates to the user accounts on the managed servers are synchronized automatically without systems administrator or user intervention. Updates to the user account are based on central server information and can include password changes, initial resource access or other user account attributes.

Abstract: A data storage system is described that simultaneously stores incoming data in a plurality of different digital formats linked together to permit economical accessibility and browsing of stored content by providing user access to reduced-resolution versions of stored format. Synchronization information correlates the same content stored in different digital formats to provide a means to reflect an edit of content in one format to the content stored in the other formats without manual editing of content in each format.

Abstract: A slow Phase Locked Loop (PLL) is utilized to prevent an abrupt change to a video display containing multiple images when the source of the synchronization is changed. Such displays include Picture in Picture (PIP) television systems and computer displays. By appropriate buffering and memory management, visual disruptions can be minimized by slowly synchronizing the display synchronization signals to the new synchronization source. The slow synchronization also produces a less disruptive visual image when the source, or channel, of a single image display is changed, and allows for smooth visual transitions on displays having inertial elements, such as color wheels.

Abstract: A relational database synchronization method for synchronizing master data with data of replica machines, which data is updated usually with the replica machines disconnected from a master machine, so that there may be no inconsistency among the data. After a replica machine is connected to the master machine via a network at an arbitrary time, it extracts records of which the day of last update is later than a master differential extraction completion time, from replica data as replica differentials, and the master machine extracts records of which the replica differential reflection time is later than the master differential extraction completion time, from the master data as master differentials, updates the master differential extraction completion time to the current time, and causes the replica differentials to be reflected in the master data. The replica machine then causes the master differentials to be reflected in the replica data and updates the master differential extraction completion time. This completes the synchronization process and the connection with the master machine may be cut off thereafter at an arbitrary time.

Abstract: A demand-driven, mixed-model manufacturing line design system utilizes Demand Flow Technology to design an efficient mixed-model manufacturing line. Concurrent manufacture of several products in a continuous flow, mixed-model product line designed utilizing the design system exhibits essentially none of the inefficiencies associated with mixed-model, batch-oriented manufacturing lines. The method according to the present invention includes a product synchronization step for synchronizing product flow between unit processes, a resource balancing step to ensure sufficient resources are provided at each process, thereby reducing the product cycle time at each process to be approximately equal to an operational cycle time calculated for each process, a cell definition step for consolidating constant volume processes, an operational definition step for grouping tasks associated with the consolidated processes within each cell, and an operation balancing step for defining additional cells based on actual product cycle time diversity. A design system according to this invention includes a computer system wherein machine readable code accessible to the computer system enables execution of the above described method.

Abstract: A method in a data processing system for locating a correct synchronization point in a data stream containing a plurality of video data packets and a plurality of audio data packets. A data stream is monitored for an audio synchronization factor within an audio data packet and for a video synchronization factor within a video data packet. In response to detecting a video synchronization factor in the video data packet, a first audio data packet from the plurality of audio data packets after the video data packet is examined to determine whether the first audio data packet contains an audio synchronization factor. In response to detecting an audio synchronization factor in the audio data packet, a data packet immediately following the audio data packet is examined to determine whether the data packet is a video data packet containing a video synchronization factor. The synchronization point is located in the video data packet in response detecting an audio synchronization factor in the first audio data packet after the video data packet containing the video synchronization factor. The synchronization point is located in the audio data packet in response to detecting the video synchronization factor in a video data packet immediately after the audio data packet. The synchronization point is used to set a start point to begin presentation of the audio and video data from the data stream.

Abstract: A method and apparatus for synchronizing a Viterbi detector to data frames corresponding to code words read from of a medium is provided. A timing pattern and a synchronization pattern is provided, the detector is synchronized to the synchronization pattern based upon the timing pattern, the detector is further synchronized to the data frame based upon the synchronization pattern

Abstract: Embodiments of the invention comprise a method and apparatus for synchronizing interface objects of an application's graphic user interface (GUI) with underlying data. A design tool is used in embodiments of the invention to specify an interface object's binding properties. Data binding properties can define an association between an interface object and underlying data for synchronization purposes. In addition, a validation binding can be specified for an interface object that can be used to validate the data entered via the interface object. An expression binding associates an interface object to a plurality of interface objects and/or underlying data sources that contain data used in evaluating an expression the result of which is displayed in the interface object. A query expression binding associates a plurality of interface objects and/or underlying data sources and to an evaluatable expression the result of which is used in a query to retrieve a data source's data. A binding manager manages the bindings (e.g., data, expression and validation bindings) defined at design time or at run time. Further, the binding manager registers with the program code (e.g., instances of object classes) that manages the bound interface objects and underlying data. The binding manager is notified, when a change occurs to an interface object or the underlying data. The binding manager processes the change request to ensure that bound interface objects and/or data sources remain synchronized.

Abstract: A system and method synchronizes multiple data stores and achieves data consistency in a non-transactional multiprocessing computer system. Processes are paused and later resumed according to their position in a dependency tree of the system. The data input sources of the system are in effect disabled and any data flow currently in progress in the system is flushed out the various data flow paths to the different data stores. When this process is complete, each of the multiple data stores is synchronized and the data is in a consistent state.

Abstract: Because correct configuration data is essential to the operation of any RAID system, and because multiple copies of the configuration data are kept, not only in the RAID controller itself, but also in each disk drive unit in the configuration, it is imperative that the various copies of the configuration data do not become "out of synchronization", which means that one or more copies of the configuration data are different from one or more other copies of the configuration data. To maintain synchronization of all copies of the configuration data, the current invention compares the configuration data stored in the RAID controllers' NVRAM to that of the current system, and records any new, non-responding, repositioned or unidentified storage devices in a change list. The identities and the attachment points of any storage devices in the change list are then displayed to the user, and various options for correcting the lack of synchronization are provided by enabling one or more function keys that may be selected by the user. One such function key, an "accept change" key, causes the configuration data to be modified by changing the current operational state of any non-responding storage device. A "configuration adjustment" key, when selected by the user, causes the configuration data to be modified to reflect any changes in the attachments points of any repositioned storage deices. An "import configuration" key causes the configuration data to be changed to correspond to that of an unidentified storage device. And a "retry" key gives the user an opportunity to rearrange the system and then re-compares the configuration data in the controller to the current system configuration. When the system is operating in un-attended mode, means are disclosed to automatically perform the "accept change", "configuration adjustment" and "import configuration" functions in priority order so long as the "retry" key has not been enabled. The retry key implies attended operation.