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 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.

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.

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.

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.

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.

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.

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 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.