Abstract: An MR apparatus 100 performs a sequence for acquiring an echo train from a subject. The MR apparatus 100 comprises upper-limit-value determining unit for determining an upper limit value etl_max for the echo train length based on a value X1 and a value X2, the value X1 including echo spacing ESP and a lower limit value TEz_max for a maximum echo time. The MR apparatus 100 further comprises unit for obtaining an echo train length based on the upper limit value etl_max for the echo train length and a number of views ypoint in which data acquisition is performed.

Abstract: In a method and magnetic resonance (MR) apparatus for determining diffusion-weighted image data, first raw data are acquired with a first diffusion weighting, and the first raw data are assigned to a first k-space matrix. Second raw data are acquired with a second diffusion weighting, and the second raw data are assigned to a second k-space matrix. The first k-space matrix and the second k-space matrix are different from one another at at least one position. The diffusion-weighted image data are determined in a processor based on the first raw data and the second raw data.

Abstract: The invention provides for a magnetic resonance imaging system. Instructions cause a processor (136) controlling the magnetic resonance imaging system to modify (200) pulse sequence data by omitting at least some of the phase encodings (408) that encode for volumes outside of the field of view. The pulse sequence data specifies the acquisition of a stack (128) of two dimensional slices of a field of view (126). The pulse sequence data further specifies phase encoding in a direction (130) perpendicular to the two dimensional slices. The pulse sequence data specifies a maximum SEMAC factor (400). The maximum SEMAC factor specifies a maximum number of phase encoding steps in the perpendicular direction for each of the two dimensional slices. The instructions further cause the processor to determine (202) a slice SEMAC factor for each of the stack of two dimensional slices. The slice SEMAC factor is determined by counting the phase encoding steps that encode for regions within the field of view.

Abstract: A system and method for magnetic resonance imaging is provided. The method may include: determining a scanning parameter, wherein the scanning parameter includes one or more predetermined values; obtaining one or more MR signal sets based on the one or more predetermined values; generating one or more original images based on the one or more MR signal sets, wherein an original image corresponds to an MR signal set; determining one or more virtual values associated with the scanning parameter; and generating one or more virtual images based on the one or more virtual values and the one or more original images, wherein a virtual image corresponds to a virtual value.

Abstract: The invention relates to a method of MR imaging of an object (10) placed in an examination volume of a MR device (1). The method comprises the steps of: subjecting the object (10) to an imaging sequence comprising multi-slice RF pulses for simultaneously exciting two or more spatially separate image slices, acquiring MR signals, wherein the MR signals are received in parallel via a set of RF coils (11, 12, 13) having different spatial sensitivity profiles within the examination volume, and reconstructing a MR image for each image slice from the acquired MR signals, wherein MR signal contributions from the different image slices are separated on the basis of the spatial sensitivity profiles of the RF coils (11, 12, 13), and wherein side-band artefacts, namely MR signal contributions from regions excited by one or more side-bands of the multi-slice RF pulses, are suppressed in the reconstructed MR images on the basis of the spatial sensitivity profiles of the RF coils (11, 12, 13).

Abstract: In a method and magnetic resonance (MR) apparatus for avoiding artifacts in scan data recorded by execution of a spin-echo sequence, an excitation pulse is radiated, at least one refocusing pulse is radiated, and at least one echo signal is read out. Following the radiation of the excitation pulse and before the readout of the at least one echo signal, at least two artifact-avoidance gradients with different amplitudes are activated, wherein the moments of the artifact-avoidance gradients balance each other.

Abstract: In a method and magnetic resonance (MR) apparatus for recording calibration data for establishing convolution kernels for GRAPPA algorithms for reconstruction of image data from measurement data recorded using echo planar imaging with simultaneous recording of a number of slices of a slice stack. A slice GRAPPA algorithm is used to reconstruct the image data of the individual slices and an inplane GRAPPA algorithm is used to reconstruct undersampled magnetic resonance data within the slices.

Abstract: Provided is an electric current sensor with which it is possible to reduce errors arising between the true value of an alternating current and a current value inferred from a detection signal during detection of the alternating current by the electric current sensor. The electric current sensor is provided with a magnetic flux detection unit 11 for detecting the alternating current by detecting the magnetic flux produced by the alternating current flowing through a bus bar, and a memory 15 for storing settings data based on detection values resulting from the detection of a prescribed calibration current flowing through the bus bar by the magnetic flux detection unit 11.

Abstract: A wireless communication apparatus includes a receiver configured to receive a plurality of beams output from external devices, the beams having directions different from each other, respectively, a memory, a processor coupled to the memory and configured to decide ranking of receiving powers of beams based on the receiving powers received by the receiver, calculate an estimated direction of the beam corresponding to the highest receiving power based on comparison of a receiving power whose ranking decided by the ranking is a predetermined ranking or lower with a receiving power whose ranking is higher than the predetermined ranking, and output a signal indicating the calculated estimated direction.

Abstract: A dual axis solar tracker is provided. The dual axis solar tracker includes a moving platform, a fixed platform, a serial chain, a parallel chain and a driving device. The moving platform is supported by the serial chain and driven by the parallel chain, forming a parallel tracking mechanism. The driving device is configured to drive the parallel chain to motion so as to drive the moving platform to rotate around vertical and horizontal axes. The dual axis solar tracker of the present disclosure has a larger workspace, a better tracking performance and advantages of high rigidity, low energy consumption, small driving torque and low inertia, etc.

Abstract: An automatic tracking imaging system that remotely controls a camera in a control terminal and images a target while automatically tracking the target, the control terminal includes a target position detection unit that detects a position of the target, a control delay time estimation unit that estimates a time T at which a control delay occurs, a target position prediction unit that predicts a position of the target after the time T, a control amount calculation unit that calculates a control amount of pan and/or tilt of the camera required to move a center of an imaging screen to a predicted position of target, a determination unit that determines whether or not the target prediction position belongs to a dead zone, and an instruction unit that instructs the camera to execute the pan and/or tilt, and the camera is instructed to execute pan and tilt from the instruction unit.

Abstract: Wireless electronic devices suitable for tracking a terrestrial object within a close range, and more particularly, an object in continuous or intermittent movement which is bearing a specific device. A device and method for tracking the bearer of a specific electronic device, in an open or closed space using a second device connected to the first by a data link. Methods for determining the exact coordinates of the bearer in movement in a Cartesian plane centered on the second device which may also be itself in movement.

Abstract: A communications device includes: a receiver configured to receive signals including at least one positioning reference signal transmitted in each of a plurality of time units; at least one antenna connected to the receiver; a motion detector configured to determine a relative local position of the communications device; and a controller configured to generate a measurement data set including plural measurement samples of at least a phase of the positioning reference signal according to a sampling rate, and a location of the communications device at which the phase of the positioning reference signal was determined. The controller is configured to estimate a relative angle of arrival of the received radio signals, used to determine an estimation of a location of the communications device, wherein the controller is configured to adapt at the rate of sampling to generate the measurement data set in accordance with predetermined conditions.

Abstract: An airborne shootings detection and piloting aid equipment is disclosed for an aircraft including a multi-sensor system supplying signals representing an environment of the aircraft including at least one system supplying a signal, referred to as an LWIR/MWIR signal, representing infrared radiation lying the far infrared or mid-infrared range; piloting aid means for obtaining first piloting information including information representing obstacles present in the environment of the aircraft; and shootings detection means for obtaining second piloting information including information representing shootings in the vicinity of the aircraft, the piloting aid means and the shootings detection means using signals representing an environment of the aircraft including at least the LWIR/MWIR signal; and obtaining means for obtaining piloting aid parameters from first and second piloting information.

Abstract: A method for detecting the presence of a signal in a frequency spectrum is provided. The method includes receiving the frequency spectrum. The power spectral density of the received frequency spectrum is estimated. A plurality of frequency bins are segmented for the frequency spectrum based on the estimated power spectral density. For segments with an estimated power spectral density above a first threshold, a radar spectral signature matching algorithm is applied to detect the presence of the signal and for segments with a power estimate below the first threshold and above a second threshold, additional techniques are applied to detect the presence of the signal.

Abstract: Provided is a frequency selective surface including a conductor plane (101), nine loop slots (102) each formed to be surrounded by the conductor plane (101), and a capacitance component (103) disposed to straddle the loop slots (102) in a width direction, both ends of the capacitance component being connected to the conductor plane (101) at a position near the loop slots (102). The conductor plane (101) and the loop slots (102) each formed to be surrounded by the conductor plane (101) constitute a unit cell (110). The unit cells (110) are two-dimensionally periodically arranged. One or more (four in the case of FIG. 1) capacitance components (103) disposed to straddle the loop slots (102) in the width direction are provided for each loop slot (102). Operating frequencies can be easily changed by adjusting only a component connected to the unit cell, or a part of metallic patterns.

Abstract: A signal receiver includes receive circuitry. The signal receiver further includes a processor coupled to the receive circuitry and configured to receive, from a filter, a stream of samples including a first set of samples. A data rate of an input of the filter may correspond to a data rate of an output of the filter. The first set of samples includes multiple samples. The processor is further configured to perform a detection operation on the first set of samples. The processor is further configured to detect a signal emitter based on the detection operation.

Abstract: There are provided correlation process units 5-1 (5-2, . . . , and 5-N) for performing a cross-correlation process between replicas of a plurality of mutually orthogonal transmission signals and reception signals of receiving antenna elements 3-1 (3-2, . . . , and 3-N) and outputting a plurality of signals after the cross-correlation process, and a weighting unit 6 for weighting the plurality of signals after the cross-correlation process outputted from the correlation process units 5-1 to 5-N in accordance with the arrangement of transmitting antennas 2-1 to 2-3 and the receiving antenna elements 3-1 to 3-N and an antenna directivity pattern, and a signal combination unit 10 combines the plurality of signals after the cross-correlation process that are weighted by the weighting unit 6.

Abstract: Data is received characterizing a plurality of measurements for a scene received by a plurality of sensor elements forming a sensor array. A plurality of scene sub-domains is mapped to the plurality of sensor elements. A plurality of voxels associated with one of the plurality of scene sub-domains is mapped to a plurality of measurement sub-domains. One or more scattering coefficients of the scene is determined by applying the mapping to the received data. Related apparatus, systems, techniques, and articles are also described.

Abstract: The ranging system has an axis defining azimuthal coordinates around the axis; a panoramic projector adapted to project an illumination beam towards azimuthally-spaced areas around the axis; a panoramic collector being adapted to receive a return light beam from illuminated areas and to collect the return light beam onto a focal area; an array of time-of-flight (ToF) sensors positioned at the focal area, each ToF sensor of the array being adapted to sense an intensity of the return light beam incoming from the azimuthally-spaced areas; and a computing device configured to operate the panoramic projector and the array of ToF sensors in a synchronized manner allowing to determine, for each ToF sensor of the array, a range value indicative of the range between the panoramic projector and a target positioned in at least one of the azimuthally-spaced areas.

Abstract: Provided is an ultrasound diagnosis apparatus including a probe configured to transmit a plurality of plane waves at a plurality of steering angles and a controller configured to determine the plurality of plane waves so that a grating lobe of a synthetic transmit focusing beam pattern using the plurality of plane waves is located outside a region of interest.

Abstract: Two or more objects, or an object and an environment are each fitted with two or more range measurement devices. Each of the range measurement devices is provided with a transceiver capable of outputting a unique code and information that can be used in range measurement, and receiving from other range measurement devices unique codes and information that can be used in range measurement. Range measurements from range measurement devices on the object or located in the environment are used to derive the relative position of the range measurement devices, from which a relative position of the objects, or of the object and an environment can be derived.

Abstract: Methods and apparatus to determine an accurate distance to a target using reference signal interpolation is disclosed. An example apparatus includes an interpolator to receive a first sample of a reference signal and a second sample of a reference signal; and interpolating a reconstructed reference signal sample based on the first and second samples, the reconstructed reference signal corresponding to the reference signal; a correlator to generate a plurality of phase-shifted, reconstructed reference signals; and correlate each of the plurality of phase-shifted, reconstructed reference signals with a reflected signal; and an optimal phase selector to determine an optimal phase based on the correlations and output a distance to a target based on the optimal phase.

Abstract: Methods and apparatus to determine a distance to a target using coarse and fine delay estimation based on a narrowband transmit signal are disclosed. An example apparatus includes a transducer to receive a reference signal and a reflected signal, the reflected signal being the reference signal after being reflected of a target; a filter to generate a band-pass reference signal and a band-pass reflected signal by filtering (A) reference signal samples associated with the reference signal and (B) reflected signal samples associated with the reflected signal; a correlator to generate a first correlation by correlating the reference signal samples with the reflected signal samples and a second correlation by correlating the band-pass reference signal with the band-pass reflected signal; and a delay estimator to determine a distance to the target based on the first correlation (coarse delay) and the second correlation (fine delay) and output a signal including the distance to the target.

Abstract: This invention is related to an automated traffic surveillance system to monitor traffic comprising of a plural number of Doppler radars, circuitry for processing radar signals, and data recording and displaying devices. Although the system is mainly designed for roadside traffic surveillance, it can be used in different applications, such as mounted on a host vehicle. The system will provide continuous surveillance of all incoming and leaving traffic.

Abstract: A deceleration hysteresis measuring apparatus for a soft recovery system is configured to transmit an electromagnetic wave to a pressure tube of the soft recovery system and receive the electromagnetic wave reflected from a projectile moving in the pressure tube so as to measure a distance of the projectile based on signals of the transmitted and received waves.

Abstract: This invention is related to a Video-Doppler-Radar Traffic Surveillance System comprising of multiple Doppler radars and video cameras, circuitry for processing radar and video signals, and data recording devices. Although the system is mainly designed for roadside traffic surveillance, it can be used in different applications, such as mounted on a host vehicle or on a UAV. The system will provide continuous surveillance of all incoming and leaving traffic.

Abstract: In a two-dimensional data structure stored in a memory of a weather radar apparatus, a height of an obstacle may be specified by a single parameter when the obstacle blocking a transmission signal is located in an observation area. A signal processor may process a reception signal based on blocking area specifying information. Thereby, a detection apparatus and a detecting method can specify with a smaller data amount an area where a transmission signal is blocked when performing a detection using transmission and reception signals.

Abstract: An object is to provide a laser processing device and a laser processing system capable of measuring a distance between a work and a processing head accurately and simply and capable of checking the quality of processing in real time during the processing. Provided are: a photodetector that detects the intensity of a processing laser beam split by optical path splitting means, and outputs a detection signal having a signal intensity responsive to the detected intensity together with a time of detection of the intensity; a signal intensity comparing unit that compares the signal intensities of multiple detection signals received from the photodetector; and a detection time comparing unit that compares times of detection of multiple intensities.

Abstract: Described examples include an integrated circuit having an analog-to-digital converter operable to receive an input signal derived from a light signal and convert the input signal to a digital received signal, the analog-to-digital converter operable to receive the input signal during at least one window. The integrated circuit further has a receiver operable to receive the digital received signal, the receiver operable to determine a distance estimate of an object from which the light signal is reflected based on the digital received signal. In an example, the window locations are chosen to correspond to the locations of maximum slope in the signal.

Abstract: Disclosed herein is a detector (110) containing: at least one longitudinal optical sensor (114), wherein the longitudinal optical sensor (114); and at least one evaluation device (140), wherein the evaluation device (140) is designed to generate at least one item of information on a longitudinal position of the object (112) by evaluating the longitudinal sensor signal of the longitudinal optical sensor (114). Also disclosed herein are articles containing the detector (110), and methods for optical detection of objects using the detector (110).

Abstract: A vehicle is provided that includes one or more wheels positioned at a bottom side of the vehicle. The vehicle also includes a first light detection and ranging device (LIDAR) positioned at a top side of the vehicle opposite to the bottom side. The first LIDAR is configured to scan an environment around the vehicle based on rotation of the first LIDAR about an axis. The first LIDAR has a first resolution. The vehicle also includes a second LIDAR configured to scan a field-of-view of the environment that extends away from the vehicle along a viewing direction of the second LIDAR. The second LIDAR has a second resolution. The vehicle also includes a controller configured to operate the vehicle based on the scans of the environment by the first LIDAR and the second LIDAR.

Abstract: System and method for calculating distance between objects is disclosed. Location data of a first object is generated. Location data of a second object is obtained. The location data comprise Global Positioning System (GPS) coordinates. The location data of the first object and the second object is compared and a value of distance between the first object and the second object is calculated. The value of distance is converted into a speech output and transmitted in the form of a notification.

Abstract: Disclosed embodiments include a method and apparatus for determining an unmanned vehicle positioning accuracy. In some embodiments, the method comprises: acquiring positioning coordinate information obtained by real-time positioning based on sensing positioning data of the unmanned vehicle; determining real coordinate information of the unmanned vehicle based on GPS data, IMU data and laser point cloud data of the unmanned vehicle; matching the obtained positioning coordinate information with the determined real coordinate information, and determining the positioning accuracy of the unmanned vehicle based on a matching result. According to technical solutions of some embodiments, the positioning accuracy of the unmanned vehicle can be determined with a higher accuracy, and preparation is made for determining a travel route of the unmanned vehicle based on the positioning result.

Abstract: In a location estimation device, a change detection unit detects a point of change in the width of a roadside structure as a width change point. A width correction unit calculates a width deviation between a first relative location of the roadside structure on a map data segment and a second relative location of the roadside structure obtained based on shape information of the roadside structure in the width direction of a vehicle. The width correction unit corrects, as a function of the width deviation and a positional accuracy of the vehicle in the travelling direction, an estimated location of the vehicle in the width direction when it is determined that there is the point of change in the width of the roadside structure in the travelling direction of the vehicle.

Abstract: A system, method and an apparatus are provided for imaging a target object, such as, e.g. a pipeline or aircraft, and may include an articulated segmented x-ray detector comprising a plurality of individual x-ray detector segments, which may be CMOS detectors or other type of semiconductor detector, articulately connected to one another. The articulately connections permit rotation of each x-ray detector segments which also permits conformity to the shape of a target object. A camera controller may be connected to each of the plurality of individual x-ray detector segments for receiving image data from each individual x-ray detectors. A flexible mat containing x-ray blocking objects may be connected to the articulated segmented x-ray detector to provide reference potions in the image data and for use in processing the image data.

Abstract: An apparatus for detecting X-ray, comprising: an X-ray absorption layer comprising an electrode; a first voltage comparator configured to compare a voltage of an electrode to a first threshold; a second voltage comparator configured to compare the voltage to a second threshold; a counter configured to register a number of X-ray photons absorbed by the X-ray absorption layer; a controller; the controller is configured to start a time delay from a time at which the first voltage comparator determines that an absolute value of the voltage equals or exceeds an absolute value of the first threshold; the controller is configured to activate the second voltage comparator during the time delay; the controller is configured to cause the number registered by the counter to increase by one, if, during the time delay, the second voltage comparator determines that an absolute value of the voltage equals or exceeds an absolute value of the second threshold.

Abstract: Disclosed herein is an apparatus suitable for detecting x-ray, comprising: an X-ray absorption layer comprising an electrode; an electronics layer, the electronics layer comprising: a substrate having a first surface and a second surface, an electronics system in or on the substrate, an electric contact on the first surface, a via, and a redistribution layer (RDL) on the second surface; wherein the RDL comprises a transmission line; wherein the via extends from the first surface to the second surface; wherein the electrode is electrically connected to the electric contact; wherein the electronics system is electrically connected to the electric contact and the transmission line through the via.

Abstract: Disclosed herein is a method of making an apparatus suitable for detecting x-ray, the method comprising: obtaining a substrate having a first surface and a second surface, wherein the substrate comprises an electronics system in or on the substrate, wherein the substrate comprises a plurality of electric contacts are on the first surface; obtaining a first chip comprising a first X-ray absorption layer, wherein the first X-ray absorption layer comprises an electrode; bonding the first chip to the substrate such that the electrode of the first X-ray absorption layer is electrically connected to at least one of the electrical contacts.

Abstract: An arrangement for detecting neutrons. In an aspect, the arrangement includes a first neutron detector including a neutron-sensitive substance, and the first neutron detector having an associated gain performance. The arrangement includes a second neutron detector including neutron-sensitive substance, and the second neutron detector having an associated gain performance. The gain performance of the second neutron detector matching the gain performance of the first neutron detector. In an aspect, the arrangement includes a first neutron detector including at least some helium. The arrangement includes a second neutron detector including at least some helium and at least some Boron-10.

Abstract: A sensor system for a seismograph functions as a hybrid between a digital sensor and an analog sensor. The sensor system has an analog output combined with digital information about the sensor. The sensor system uses both an analog section and a digital section to provide information to a collection device. The digital section can provide digital information regarding the operation of the sensor(s) of the sensor system. After the digital section completes the exchange of digital information, the digital section can be deactivated and the analog section can be used to provide analog sensor information to the collection device. The collection device can use the digital information from the digital section to process the analog sensor information from the analog section.

Abstract: A method for iteratively inverting seismic data to jointly infer a model for at least P-wave velocity and attenuation parameters of the subsurface, the method including: jointly inverting the P-wave velocity and attenuation parameters with an iterative visco-acoustic full wavefield inversion process, wherein the iterative visco-acoustic full wavefield inversion process includes computing a gradient of an objective function, the objective function measuring a misfit between all or part of the seismic data and corresponding model-simulated seismic data; for each of the P-wave velocity and attenuation parameters, computing a search direction in model space from the gradient; determining line search step sizes ? and ? for the search directions for the P-wave velocity and attenuation parameters, respectively, wherein a ratio of the step sizes is a function of the P-wave velocity parameter; and using the step sizes ? and ? and the search directions for each of the P-wave velocity and attenuation parameters, computi

Abstract: A method for estimating in real time the geomechanical properties using drilling data and an accurate drilling model. An initial structural framework and initial distribution of the geomechanical and other rock properties is adjusted in real time by estimating accurately the corrected mechanical specific energy (CMSE), which is then used to estimate the geomechanical and other rock properties. For example, the updated geomechanical model can be used to geosteer the well toward the brittle zones that will achieve the best stimulation when using hydraulic fracturing in unconventional wells.

Abstract: Computing device, computer instructions and method for calculating a characteristic of the earth based on recorded seismic data related to a subsurface. The method includes receiving well log data; calculating a statistical model based on the well log data; calculating a reflectivity R of the subsurface based on an intercept A and a gradient B of the statistical model; calculating a reconstructed gather D based on the reflectivity R and a wavelet model W; calculating parameters wn of the wavelet model W with a first inversion function C that depends on (i) the reconstructed gather D, (ii) a recorded gather D0, and (iii) a probability density function (pdf) associated with the statistical model; and calculating the characteristic of the earth for the subsurface, based on the parameters wn of the wavelet model W and the recorded gather D0.

Abstract: A seismic noise mitigation method. The method comprises identifying a wavenumber of a component in a residual wavenumber spectrum having a largest norm based on a preconditioned residual wavenumber spectrum. A contribution to the residual wavenumber spectrum from the identified wavenumber component, is subtracted therefrom. A next residual wavenumber spectrum is based thereon and a relative residual computed based on that. The identifying, subtracting and calculating are repeated until a first to occur termination condition selected from the group consisting of: a current relative residual is less than a threshold residual; a difference between the current relative residual and a smallest relative residual exceeds product of the smallest relative residual and a preselected threshold factor; and a difference between a current number of iterations and a number of iterations corresponding to a currently encountered smallest relative residual encountered exceeds a preselected threshold number of iterations.

Abstract: A system (1) for operating a subsea sensor field (2), comprises an automated underwater vehicle—AUV (10) and a subsea service station (13). A sensor (11, 12) in the sensor field (2) comprises a permanently installed base unit (11) and a removable control unit (12). The AUV (10) moves control units (12) to the service station (13) for charging and updating, and then back to the base units. The permanent positions of the base units (11) facilitate time-lapse surveys, and saves energy as heavy equipment may remain on the seafloor.

Abstract: A sensor including a set of coils. The set of coils include a first coil and a second coil, wherein the first coil upon receiving energy, generates an electromagnetic near-field, such that the electromagnetic near-field provides at least a portion of the energy to the second coil through inductive coupling, inducing a current to pass through the set of coils. Further, a detector for measuring a voltage across at least one of the first coil or the second coil, wherein the detector includes a voltmeter. Finally, a processor for detecting a presence of a target structure in proximity to the set of coils upon detecting a change in a value of the voltage, wherein the target structure is an electromagnetic structure moving at a distance from the set of coils.

Abstract: Provided is a detection circuit that has a first inductor connected to two opened input ends and detects an external signal having a waveform with a gradient at each input end. The detection sensor further includes an output circuit that has a second inductor magnetically coupled with the first inductor as a primary side. In the output circuit, a third inductor constituting a delay circuit having one end connected to an intermediate tap of the second inductor is connected. Diodes are respectively connected to terminals of the second inductor in a forward direction. Other terminals of the diodes are connected to another terminal of the third inductor via elements each having an impedance characteristic. The output circuit outputs a detection signal detected at the input ends, from the other terminal(s) of at least one of the diodes.

Abstract: Methods and systems of electromagnetic sensing in a wellbore are presented in this disclosure for monitoring annulus fluids and water floods. An array of transmitters and one or more receivers are located along a casing in the wellbore. A transmitter in the array and one of the receivers can be mounted on a same collar on the casing forming a transmitter-receiver pair. The receiver can receive a signal originating from the transmitter and at least one other signal originating from at least one other transmitter in the array, wherein the signal is indicative of a fluid in the wellbore in a vicinity of the transmitter-receiver pair and the at least one other signal is indicative of another fluid in a formation around the wellbore. The receiver can further communicate, via a waveguide, the signal and the at least one other signal to a processor for signal interpretation.

Abstract: A nuclear magnetic resonance logging tool is provided. The tool includes a flexible or semi-flexible circuit board, at least one capacitor mounted on board, and a controller programmed to apply sequential pulses to the at least one capacitor of the tool with a spacing of less than 600 ?s between adjacent pulses. Ring down time induced by the at least one capacitor in response to pulses is less than about 200 ?s.