Abstract: Disclosed are a method and system for evaluating sonar self-noise at a ship design stage. The method includes: building a ship structure full-scale geometric simulation model; acquiring loss factors and sonar transducer space outfitting acoustic absorption coefficient material parameters; acquiring mechanical excitation, hydrodynamic excitation, and propeller excitation; inputting the loss factors and the sonar transducer space outfitting acoustic absorption coefficient material parameters into an established statistical energy evaluation model, and applying a mechanical excitation to a face plate of foundation of the built ship structure full-scale geometric simulation model, applying a hydrodynamic excitation to the surface of a ship hull, and applying a propeller excitation to a stern shaft to perform calculation of sonar self-noise of a ship to obtain total spectral density level of the sonar self-noise; and evaluating spectral density level calculation results by index requirements.

Abstract: Disclosed are a method and system for evaluating sonar self-noise at a ship design stage. The method includes: building a ship structure full-scale geometric simulation model; acquiring loss factors and sonar transducer space outfitting acoustic absorption coefficient material parameters; acquiring mechanical excitation, hydrodynamic excitation, and propeller excitation; inputting the loss factors and the sonar transducer space outfitting acoustic absorption coefficient material parameters into an established statistical energy evaluation model, and applying a mechanical excitation to a face plate of foundation of the built ship structure full-scale geometric simulation model, applying a hydrodynamic excitation to the surface of a ship hull, and applying a propeller excitation to a stern shaft to perform calculation of sonar self-noise of a ship to obtain total spectral density level of the sonar self-noise; and evaluating spectral density level calculation results by index requirements.

Abstract: Aspects of the subject technology relate to systems and methods for identifying the quality of cement bonding of an exterior surface of a wellbore casing to an Earth formation. Methods of the present disclosure may allow for bond indexes to be identified in real-time as a cementing operation is performed even when tools that perform the cementing operation generate acoustic noise that interfere with measurements used to evaluate cement bonding quality. These methods may include transmitting acoustic signals, receiving acoustic signals, filtering the received acoustic signals, identifying magnitude and attenuation values to associate with the received acoustic signals, and comparing trends in the magnitudes with the identified attenuation values. These methods may also include correcting attenuation values associated with measured data based on a set of correction rules such that bond indexes can be identified. Such correction rules may be associated with data generated by a computer model.

Abstract: This disclosure is directed to techniques in which a first user in an environment scans visual indicia associated with an item, such as a barcode, before handing the item to a second user. One or more computing devices may receive an indication of the scan, retrieve image data of the interaction from a camera within the environment, identify the user that received the item, and update a virtual cart associated with the second user to indicate addition of the item.

Abstract: Described is a multiple-camera system and process for re-identifying a user located in a materials handling facility based on user patterns and/or descriptors representative of the user. In one implementation, a user pattern and/or a plurality of descriptors representative of a user are maintained as a position of a user is tracked through a materials handling facility. If the tracking of the user is lost, the last known position is stored with the user pattern and/or descriptors. If a new object is detected and confirmed to be a user, a user pattern and/or descriptors of the new object are compared with the stored user pattern and/or descriptors to determine if the new object is the user.

Abstract: This disclosure is directed to techniques in which a first user in an environment scans visual indicia associated with an item, such as a barcode, before handing the item to a second user. One or more computing devices may receive an indication of the scan, retrieve image data of the interaction from a camera within the environment, identify the user that received the item, and update a virtual cart associated with the second user to indicate addition of the item.

Abstract: Methods and systems for removing tool mode waveforms. The method may include disposing a bottom hole assembly (BHA) into a wellbore. The BHA may comprise at least one transmitter configured to transmit a pressure pulse and at least one receiver configured to record one or more waveforms. The method may further comprise performing a logging-while-drilling (LWD) operation in which the one or more waveforms are recorded with the at least one receiver, transmitting the one or more waveforms to an information handling system, removing one or more tool mode waveforms from the one or more waveforms to form an updated set of waveforms, and forming differential phase time semblance map based at least in part on the updated set of waveforms. The system may comprise the BHA and information handling system configured to remove one or more tool mode waveforms.

Abstract: Methods to estimate formation shear wave slowness from multi-firings of different types of acoustic sources and multi-mode dispersion estimation systems are presented. The method includes obtaining waveform data of waves traversing through a downhole formation, where the waves are generated from multi-firings of different types of acoustic sources. The method also includes performing a multimode dispersion analysis of the waveform data for each firing of the multi-firings, and removing one or more tool waves generated from the multi-firings. The method further includes determining a formation type of the formation the waves traverse based properties of the waves and determining an initial shear wave slowness estimate of the waves. The method further includes generating a modeling of the waves, and reducing a mismatch between the modeling of the waves and a slowness dispersion of the waves to improve the modeling of the waves.

Abstract: An acoustic transducer includes a substrate element having a first side, and a second side opposite the first side. The acoustic transducer also includes first and second piezoelectric elements coupled to the first side, and third and fourth piezoelectric elements coupled to the second side. The first piezoelectric element has a first polarity, and the second piezoelectric element has a second polarity different than the first polarity. The third piezoelectric element has a third polarity, and the fourth piezoelectric element has a fourth polarity different than the third polarity.

Abstract: Methods to estimate formation shear wave slowness from multi-firings of different types of acoustic sources and multi-mode dispersion estimation systems are presented. The method includes obtaining waveform data of waves traversing through a downhole formation, where the waves are generated from multi-firings of different types of acoustic sources. The method also includes performing a multimode dispersion analysis of the waveform data for each firing of the multi-firings, and removing one or more tool waves generated from the multi-firings. The method further includes determining a formation type of the formation the waves traverse based properties of the waves and determining an initial shear wave slowness estimate of the waves. The method further includes generating a modeling of the waves, and reducing a mismatch between the modeling of the waves and a slowness dispersion of the waves to improve the modeling of the waves.

Abstract: To generate dispersion curves for acoustic waves in a radially layered system, a matrix M containing solutions to the wave equation subject to the boundary conditions of the system is constructed. The reciprocal condition number (RCN) of the matrix M is determined as a function of acoustic wave frequency and slowness. The local minima of the RCN in the frequency-slowness plane produces the dispersion curves corresponding to allowable acoustic modes in the system. A sensitivity analysis which identifies the dispersion curves dependent on a selected parameter. The dispersion curves independent of the perturbed parameters are eliminated by perturbing the modeling parameters and generating the RCN of the perturbed matrix M and then subtracting the RCN values of the unperturbed matrix M, leaving the dispersion curves that exhibit dependence on the selected parameter.

Abstract: Methods to estimate formation slowness from multi-borehole modes and multi-mode dispersion estimation systems are presented. The method includes obtaining waveform data of a plurality of waves traversing through a downhole formation, wherein each wave of the plurality of waves has a different threshold cutoff frequency, and performing a multimode dispersion analysis of the waveform data to generate a semblance map of the wave comprising the plurality of waves. The method also includes obtaining a slowness dispersion of a wave of the plurality of waves, and determining a formation type of the wave based on one or more properties of the plurality of waves. The method further includes determining an initial body wave slowness estimate of the wave, generating a modeling of the wave, and reducing a mismatch between the modeling of the wave and the slowness dispersion of the wave to improve the modeling of the wave.

Abstract: Features are disclosed for recognizing network-based user in a physical location. A system is provided for generating and detecting a scannable code. A time-sensitive scannable code unique to the user may be generated and presented by an electronic device such as a smartphone. The time-sensitive scannable code may be scanned at transaction terminal in the physical store. Using the scannable code, the system may securely determine that user profile information from the user's network-based activity may be provided to the transaction terminal for use in the physical location.

Abstract: This disclosure describes techniques for determining when to transition a service-provider application between an in-store mode of operation and an online mode of operation using time as a proxy for location of a mobile device executing an application. When a user arrives at a physical location of the service provider, the user may provide an indication of this arrival via the application. In response, the application may transition from the online mode of operation to the in-store mode of operation. Further, the application may set a timer for a predefined amount of time and, after this amount of time elapses, may transition from the in-store operation mode back to the online operation mode.

Abstract: Techniques for calculating and visually presenting multiple acoustic modes that have different formation slowness are disclosed herein. The techniques include methods for receiving time-domain waveforms from adjacent formations in a borehole, processing each of the time-domain waveforms to generate frequency-domain spectrums, selecting frequency and slowness values, and predicting travel time of a mode associated with the slowness value. In some aspects, the method further includes steps for calculating a semblance difference of the frequency-domain spectrums based on the frequency value, the slowness value and the predicted travel time. Systems and computer-readable media are also provided.

Abstract: This disclosure is directed to techniques in which a first user in an environment scans visual indicia associated with an item, such as a barcode, before handing the item to a second user. One or more computing devices may receive an indication of the scan, retrieve image data of the interaction from a camera within the environment, identify the user that received the item, and update a virtual cart associated with the second user to indicate addition of the item.

Abstract: To generate dispersion curves for acoustic waves in a radially layered system, a matrix M containing solutions to the wave equation subject to the boundary conditions of the system is constructed. The reciprocal condition number (RCN) of the matrix M is determined as a function of acoustic wave frequency and slowness. The local minima of the RCN in the frequency-slowness plane produces the dispersion curves corresponding to allowable acoustic modes in the system. A sensitivity analysis which identifies the dispersion curves dependent on a selected parameter. The dispersion curves independent of the perturbed parameters are eliminated by perturbing the modeling parameters and generating the RCN of the perturbed matrix M and then subtracting the RCN values of the unperturbed matrix M, leaving the dispersion curves that exhibit dependence on the selected parameter.

Abstract: Techniques for calculating and visually presenting multiple acoustic modes that have different formation slowness are disclosed herein. The techniques include methods for receiving time-domain waveforms from adjacent formations in a borehole, processing each of the time-domain waveforms to generate frequency-domain spectrums, selecting frequency and slowness values, and predicting travel time of a mode associated with the slowness value. In some aspects, the method further includes steps for calculating a semblance difference of the frequency-domain spectrums based on the frequency value, the slowness value and the predicted travel time. Systems and computer-readable media are also provided.

Abstract: Described is a multiple-camera system and process for re-identifying a user located in a materials handling facility based on user patterns and/or descriptors representative of the user. In one implementation, a user pattern and/or a plurality of descriptors representative of a user are maintained as a position of a user is tracked through a materials handling facility. If the tracking of the user is lost, the last known position is stored with the user pattern and/or descriptors. If a new object is detected and confirmed to be a user, a user pattern and/or descriptors of the new object are compared with the stored user pattern and/or descriptors to determine if the new object is the user.

Abstract: This disclosure describes techniques for determining when to transition a service-provider application between an in-store mode of operation and an online mode of operation using time as a proxy for location of a mobile device executing an application. When a user arrives at a physical location of the service provider, the user may provide an indication of this arrival via the application. In response, the application may transition from the online mode of operation to the in-store mode of operation. Further, the application may set a timer for a predefined amount of time and, after this amount of time elapses, may transition from the in-store operation mode back to the online operation mode.