184 results about "Virtual time" patented technology

A data management system that protects data into a continuous object store includes a management interface having a time control. The time control allows an administrator to specify a “past” time, such as a single point or range. When the time control is set to a single point, a hierarchical display of data appears on a display exactly as the data existed in the system at that moment in the past. Preferably, the visualization includes both the structure of the hierarchy (e.g., the identity of the directories, their files, databases, and the like) and also the contents of the data objects themselves (i.e., what was in the files and databases). The time control enables the management interface to operate within a history mode in which the display provides a visual representation of a “virtual” point in time in the past during which the data management system has been operative to provide the data protection service. In addition, the management interface can be toggled to operate in a real-time mode, which provides an active view of the system data as it changes in real-time, typically driven by changes to primary storage. This real-time mode provides the user with the ability to view changes that occur to a set of data currently visible on the display screen. The interface also allows an administrator to specify and manage policy including, without limitation, how long data is retained in the management system. A policy engine enables the user to assert “temporal-based” policy over data objects.

Resource requests from a plurality of schedulable entities are scheduled while limiting the maximum and minimum quality of service allocated to each schedulable entity. The resource scheduler of the present invention requires less memory maintain state information than existing rate-controlling schedulers, and is thus more easily scalable to large numbers of users. The resource scheduler also schedules resources fairly among competing schedulable entities. A fair-share scheduling algorithm is used by a resource scheduler to select resource requests to service. A rate controller checks to ensure that servicing the selected request will not cause the associated user's maximum quality of service to be exceeded. If the maximum quality of service will not be exceeded, the virtual time used in the scheduling algorithm is incremented, and the request is serviced. If the maximum quality of service will be exceeded, the virtual time is still incremented, but the request is not serviced and remains pending.

A network device that manages the flow rate of a stream of packets traveling within a network is converted from managing based on data rate to managing based on packet rate. In one embodiment, an interface receives from the device an actual length of a packet and provides to the device an effective length for the packet. A multiplexer generates the effective length by selecting the actual length during data rate mode and selecting a virtual length during packet rate mode. Various embodiments work with network devices that use various traffic management techniques. Such techniques include, but are not limited to: virtual time algorithms for determining excess packets; policing techniques that drop excess packets; and shaping techniques that buffer excess packets for possible later transmission.

A method of achieving synchronous playback of media content over the internet, such as digital video and audio, when the media content is stored on a host that does not have synchronous broadcasting software installed. Users select media sources that are accessible from one or more content servers and create a broadcast playlist. A database maintains a virtual-time record of the broadcast. A server receives a client request for the broadcast, retrieves the virtual-time record from the database, and delivers it to the client. The client then accesses the remotely-stored media source and plays it in a media player, synchronously with all other clients receiving the broadcast.

A time division-based wireless LAN communication method by use of an AP in an infrastructure mode, including, on the AP's side, receiving a time slot allocation request frame from a station, allocating time slots during which the station can transmit data based on the time slot allocation request frame, and broadcasting reservation information on allocated time slots. A time division-based wireless LAN communication system includes an AP receiving a time slot allocation request frame transmitted by a station, allocating time slots on this basis, with which the station can transmit data, and broadcasting reservation information on allocated time slots, and one or more stations transmitting the time slot allocation request frame to the AP when there is data to be transmitted, receiving reservation information on time slots allocated by the AP based on the received time slot allocation request frame, and transmitting the data according to reservation of the beacon.

The invention discloses an SCATS coil data-based traffic state online quantitative evaluation and prediction method, which relates to the traffic state online quantitative evaluation and prediction method in the technical field of traffic. The SCATS coil data-based traffic state online quantitative evaluation and prediction method comprises the following steps: acquiring traffic parameters and uploading the traffic parameters to a traffic information centre by an SCATS coil; performing quality evaluation and control on actually-measured data by a computer; performing traffic parameter virtual time sequence construction on the actually-measured data subjected to the quality evaluation and control; performing the quality evaluation and control on virtual time sequence data; performing traffic congestion automatic identification on the virtual time sequence data of the parameters; performing short multi-stage prediction on the virtual time sequence data of the traffic parameters; and on the basis of the short multi-stage prediction on the virtual time sequence time of the traffic parameters, performing traffic congestion spreading range prediction and duration prediction and issuing prediction results to a traffic administrative department to provide more forcible basis for decision making for the traffic administrative department.

A method and system is provided for the creation and playback of multiple independently produced and distributed media intended for synchronized playback. One embodiment of the invention overcomes variances in independently produced and distributed media that make accurate synchronization impossible today. The system utilizes both authoring and playback processes. During authoring, a relative virtual time code profile is generated based on the original source media in a defined associated media set. The system employs an extensible framework of multiple synchronization recognizers that analyze the source media to generate a relative virtual time code profile for the associated media set. During playback, the system's client can access the relative virtual time code profile to coordinate the synchronized playback of an associated media set. The system generates an absolute time code using the available associated media and the original relative virtual time code profile. The system can overcome significant variances between the available associated media and the original associated media such as missing content, added content, resolution differences, format differences, etc.

A method comprises scheduling, by a weighted proportional-share virtual time processor scheduler, processor access to a first consumer during a time period in which a second consumer is blocked from processor access. When the second consumer becomes unblocked from processor access, the weighted proportional-share virtual time processor scheduler determines whether the length of the time period over which the second consumer was blocked from processor access exceeds a predefined time threshold. When determined that the length of the time period over which the second consumer was blocked from processor access does not exceed the predefined time threshold, then scheduler does not update the virtual time of the second consumer before scheduling processor access for the second consumer.

An application program that describes processing of a workpiece by the machine tool in form of instruction steps is disclosed. A computer executes the application program and step-by-step determines based on a simulation program machine-dependent control commands for a controller. The machine-dependent control commands depend on a virtual time base that is independent of an actual time base. The computer determines based on a computer-internal model of the machine tool and the determined machine-dependent control commands expected actual states of the machine tool, thereby simulating execution of the machine-dependent control commands by the machine tool. The simulation program is implemented as control software in the controller.

The invention relates to a fracture-cavity type oil deposit analyzing method for water-flooding development and application thereof. According to the method, history matching is conducted on a first geologic feature parameter of multiscale reservoir bodies constructing a multiscale reservoir body distribution conceptual model to obtain a second geologic feature parameter of the multiscale reservoir bodies constructing the finely drawn multiscale reservoir body distribution geologic model. In history matching, the independent representation multi-sided conductivity is adopted for dealing with the influence caused by connection position differences of different side fractures and caves on the oil water flowing rule; the virtual time step is adopted for reflecting the oil water replacement momentary balancing effect caused by oil water density difference; for anisotropy characters of the fractures, the tensor permeability of an arbitrarily fracture of the space is obtained by the adoption of conversion of a geodetic coordinate system and a space coordinates system. The fracture-cavity type oil deposit analyzing method for the water-flooding development is used for conducting fracture-cavity type oil deposit water-flooding development and decisions, the geologic model is more accurate, the flowing rule and the oil-displacement mechanism are more complete, and optimized decision through technologies and development effect predication are more accurate and reliable.

The invention provides a method for diagnosing constant optical network units in an Ethernet passive optical network. Each optical line terminal (OLT) in the Ethernet passive optical network is connected with a plurality of optical network units (ONU). The method comprises the following steps that: when the OLT distributes and sends time slots of data to the ONUs, the OLT distributes a different virtual time slot to each ONU additionally; each ONU only sends data in the distributed time slot, and does not send data in the virtual time slot, so the stronger optical power is not detected in the virtual time slot; and the OLT periodically detects the optical power in the virtual time slot so as to judge whether a detection value is greater than a threshold, if so, determines that certain ONU in a constant state or other constant light sources exist under the OLT, and otherwise determines that all ONUs under the OLT are in a normal state. The method can quickly diagnose whether the constant ONUs exist in the Ethernet passive optical network.

A method, apparatus, and computer program product for monitoring structures using virtual time reversal signal processing. In one embodiment, a signal having a frequency range is sent into a structure in a vehicle from a fixed transmitter to form an original transmitted signal. A response to the original transmitted signal is received at a fixed sensor associated with the structure to form a received response. The received response is reversed. The reversed response is processed using a transfer function to simulate propagation of the reversed response from the fixed sensor to the fixed transmitter to form a simulated time reversed response. The simulated time reversed response is a simulation of a response of the fixed transmitter to receiving the reversed response from the fixed sensor. The simulated time reversed response is analyzed to monitor for anomalies associated with the structure.

An automated system is provided in a facility that manufactures m products, where m>0. The system comprises a software object that provides for calculation of one or more bottleneck delta virtual work in process time (“VWIP”) values. Each of the bottleneck delta VWIP values represents the amount of time until one of n bottleneck workstations begins to risk starvation, where n>0. VWIP is the amount of time a bottleneck will stay busy processing WIP that will reach the bottleneck in less time than new lot starts will reach the same bottleneck. In at least one embodiment, each of the bottleneck delta VWIP values is calculated as a mathematical function of virtual WIP time for the corresponding bottleneck workstation and a lower control limit for the corresponding bottleneck workstation. In at least one other embodiment, n>2 and the software object provides for calculation of a plurality of bottleneck delta VWIP values. The software object contains program code that provides for the foregoing functionality either directly or by invoking one or more other objects.

A system and technique for phased array antenna beam steering for transmitting and receiving without sending the waveform through an actual (physical) time delay when a time varying frequency is used as the waveform. The inventive system is adapted for use with an antenna having an array of radiating elements and includes a plurality of signal sources. Each source is adapted to provide a signal having a predetermined frequency offset signal for an associated radiating element or set of radiating elements. For transmit a plurality of first mixers is provided. Each of the first mixers is coupled to receive an excitation signal as a first input and the output from a respective one of the sources as a second input. The output of each mixer is coupled to a respective subset of the antenna radiating elements. In effect, each of the sources provides a virtual time delay. In a specific embodiment, the virtual time delay source includes a direct digital synthesizer and a digital-to-analog converter connected to receive the output thereof. A second mixer is included in each source for mixing the output of the converter with the output of a supplemental signal source. For receive the process is implemented the same way as for transmit for the range of the desired "target" return. The output of the second mixer is supplied to a respective one of the first mixers. The invention adjusts the phase and frequency of an RF waveform that is spread out in frequency and time such that each frequency arrives at the radiating elements of a phased array antenna with the phase that will steer the antenna beam in the desired direction. The relative signal phase at each radiating element is made to be independent of the signal carrier frequency and thus the antenna beam pointing is made independent of RF carrier frequency.

Nodes in a distributed system maintain virtual times according to specified rules. Each node can associate its virtual time with transactional messages that are transferred to other nodes and with log entries that are written to a log. A reference entry, which corresponds to an arbitrary point in time, is selected from a first log associated with a first node. A reference virtual time associated with the reference entry is identified. A matching entry, with an associated virtual time that appropriately corresponds to the reference virtual time, is selected from a second log associated with a second node. The first node is caused to roll-forward to the arbitrary time by processing the first log up to the reference entry. The second node is caused to roll-forward to the arbitrary time by processing the second log up to the matching entry.

The invention provides a lamb wave virtual time reversal method with a high spatial resolution. The method comprises the following steps: (1) a piezoelectric array consisting of n piezoelectric chips is arranged on a structure to be tested, (2) an injury scattering path transfer function is obtained, (3) multipath injury scattering signals are obtained and (4) focused and strengthened injury scattering signals are obtained through virtual time reversal processing. Compared with the prior art, the invention has the technical effects: (1) complex physical time reversal operation is unnecessary, the requirement on a monitoring device is low, and the operation is easy, (2) the multipath injury scattering signals are focused and strengthened at the corresponding injury part, boundary reflection and noise are prohibited and the signal-to-noise ratio of the injury scattering signals is improved effectively, and (3) the time domain of the wave crest of Lamb wave and the spatial resolution ratio of injury focus wave crest is improved.

The disclosed embodiments provide a system for providing a graph database storing a graph. During operation, the system executes one or more processes for providing the graph database. Next, the system stores a sequence of changes to the graph in a base version of the graph database. The system then branches a version of the graph database from a virtual time in the base version. Finally, the system uses the branched version to process one or more queries of the graph database.

The invention provides an underwater acoustic communication method based on virtual time reversal mirror M element bionic signal coding. The method comprises the steps that (1) binary information bit streams are subjected to serial-parallel conversion; (2) a dolphin whistles signal is selected for output through a signal code selector; (3) synchronous codes are added before coding signals, and one frame signal is generated; (4) the frame signal is subjected to power amplification and is transmitted out by an energy converter; (5) signals received by a hydrophone are firstly subjected to channel equalization; (6) the signals subjected to the channel equalization are synchronized for determining the signal start time base, and in addition, the coding signals are intercepted through the time base; (7) the coding signals are sent into M replica correlators, and the decoding is carried out according to the maximum value of output results of the correlators; and (8) the information is subjected to parallel-serial conversion and reduction, and sequences are sent. The underwater acoustic communication method has the advantages that the gain processing and anti-multipath capability is higher, bionic signals cannot be easily intercepted, and good communication concealment is realized; and the underwater acoustic communication method is particularly suitable for platforms with higher communication concealment requirements.

Various improvements are provided for prior art policing methods, including token bucket methods and virtual time policing methods. Some preferred methods of the invention involve assigning a non-zero drop probability even when the packet would otherwise have been transmitted according to a prior art policing method. For example, a non-zero drop probability may be assigned even when there are sufficient tokens in a token bucket to allow transmission of the packet. A non-zero drop probability may be assigned, for example, when a token bucket level is at or below a predetermined threshold or according to a rate at which a token bucket is being emptied. Some implementations involve treating a token bucket as a virtual queue wherein the number of free elements in the virtual queue is proportional to the number of remaining tokens in the token bucket. Such implementations may involve predicting a future virtual queue size according to a previous virtual queue size and using this predicted value to calculate a drop probability.

Lookback is defined as the ability of a logical process to change its past locally (without involving other logical processes). Logical processes with lookback are able to process out-of-timestamp order events, enabling new synchronization protocols for the parallel discrete event simulation. Two of such protocols, LB-GVT (LookBack-Global Virtual Time) and LB-EIT (LookBack-Earliest Input Time), are presented and their performances on the Closed Queuing Network (CQN) simulation are compared with each other. Lookback can be used to reduce the rollback frequency in optimistic simulations. The relation between lookahead and lookback is also discussed in detail. Finally, it is shown that lookback allows conservative simulations to circumvent the speedup limit imposed by the critical path.

A method and system for emulating a network bandwidth condition includes maintaining a queue for holding packets that are received, maintaining a virtual time that is updated whenever a packet timer is scheduled, and, for a selected packet waiting in the queue, calculating a timer expiration time based on the virtual time. A bandwidth emulation module is controlled by an emulator link that comprises a virtual network link to which a first computer is connected. One or more computers may be linked to the first computer.

A machine-implemented method includes establishing a virtual or augmented reality entity, and establishing a state for the entity having a state time and state properties including a state spatial arrangement. The data entity and state are stored, and are subsequently received and outputted at a time other than the state time so as to exhibit a “virtual time machine” functionality. An apparatus includes a processor, a data store, and an output. A data entity establisher, a state establisher, a storer, a data entity receiver, a state receiver, and an outputter are instantiated on the processor.

A method for realizing IP stream mode service in T-MMB system by utilizing MPE-FEC technique includes applying MPE-FEC technique to divide and restructure each IP data in IP service to for MPE-FEC frame form for making data be on effect of virtual time interface then packaging data to be MPE section and MPE-FEC section and adding real time parameter information in section head, fragmenting each data section and mapping fragmented data sections into MPEG-2 TS packet.

The invention relates to the field of network communication and in particular to a time delay measurement method and device for solving the great limitation of a conventional method for measuring time delay. According to the embodiment of the present invention, a master device stores at least one virtual time and periodically updates respective virtual time. The method comprises steps that the master device sends a measurement packet to a slave device, and determines a first time point according to the virtual time corresponding to the slave device when the measurement packet is sent; the master device receives a measurement response message returned from the slave device and determines a fourth time point according to the virtual time corresponding to the slave device when the measurement response message is received; the master device determines, according to the first time point, the second time point, the third time point and the fourth time, an offset between the virtual time corresponding to the slave device and the real time of the slave device; if the offset is not greater than a first threshold, the master device determines that the virtual time corresponding to the slave device is synchronized with the real time; and the master determines the one-way time delay between the master and slave devices.

The invention provides a method for realizing time limitation of software under an offline state. The software is mounted in terminal equipment; a safety container for storing virtual time is arranged in the terminal equipment; the method comprises: when the terminal equipment is started up, starting the safety container and calculating a first time difference value between current host time of the terminal equipment and host time of shutdown of the last time; revising the virtual time to the sum of current virtual time and the first time difference value; during an operation process of the terminal equipment, revising the virtual time to the sum of the current virtual time and pre-set time by the safety container at intervals of pre-set time; when detecting that the current virtual time reaches expiration time of the software, forbidding the software. According to the method for realizing the time limitation of the software under the offline state, provided by the invention, the virtual time in the safety container can be calibrated and the problem that utilization time of the software is incorrectly counted after a user adjusts the host time under the offline state is solved.

The invention discloses a virtual time inversion-based sound emission passive imaging method and an apparatus thereof. The method comprises the following steps: receiving n sound emission signals acquired by n piezoelectric patches arranged on a structure to be measured, wherein n is an integer not less than 3; carrying out virtual time reversion treatment on the sound emission signals to obtain reversed signals; extracting the envelope signals of the reversed signals; and imaging according to the envelope signals in order to obtain peak value pixel point positions used as the sound emission source positions of the structure to be measured. The virtual time inversion-based sound emission passive imaging method and the apparatus thereof allow single piezoelectric patch related undetermined absolute wave arrival time in the sound emission signals into a two piezoelectric patches related determined wave arrival time difference through the virtual time reversion treatment, is convenient to realize the highly-precious rapid imaging positioning, does not need the determination of the wave arrival time of the sound emission signals or the calibration of the performances of a piezoelectric transducer, and has low dependence on prior data.

The invention relates to a virtual time reversal underwater sound OFDM channel equalization method which is characterized by comprising the steps that 1. detecting signals for signal estimation are added into signals sent by a sending end; 2. a receiving end completes a synchronous process, and the received detecting signals are extracted, and according to the received detecting signals, channel impulse response is estimated; 3. according to the estimated channel impulse response, virtual time reversal OFDM channel equalization is completed; and 4. signals after equalization are subjected to serial-parallel conversion, circulating prefixes and circulating postfixes are removed, and a demodulation process is completed.