Abstract: A method for distributing geophones around a seismic data source includes distributing a first geophones each including a first piezoelectric system in a first region in which the seismic data source is located then distributing second geophones each including a solar cell in a second region surrounding the first region. The second geophones further include a housing, a spike provided on a bottom surface of the housing, a sensor configured to sense seismic data; a processor configured to process the seismic data, a transceiver configured to transmit the processed seismic data and receive radio frequency (RF) signals wirelessly; and a power device. The power device is coupled to the sensor, the processor and the transceiver. The power device is configured to harvest energy from an environment where the geophone is located.

Abstract: A method for distributing geophones around a seismic data source includes distributing a first geophones each including a first piezoelectric system in a first region in which the seismic data source is located then distributing second geophones each including a solar cell in a second region surrounding the first region. The second geophones further include a housing, a spike provided on a bottom surface of the housing, a sensor configured to sense seismic data; a processor configured to process the seismic data, a transceiver configured to transmit the processed seismic data and receive radio frequency (RF) signals wirelessly; and a power device. The power device is coupled to the sensor, the processor and the transceiver. The power device is configured to harvest energy from an environment where the geophone is located.

Abstract: A device, method, and non-transitory computer readable medium that for two-dimensional blind single-input multiple-output channel identification for image restoration. The method includes receiving, by a receiver having independent channels, a two-dimensional image data matrix then transforming the received two-dimensional image data matrix to a one-dimensional image vector. Channel parameters can then be estimated using the one-dimensional image vector. The method can then construct a restored image using the estimated channel parameters and the two-dimensional image data matrix.

Abstract: A system, method, and non-transitory computer readable medium that perform blind signal estimation for single-input multiple-output systems. The method can include receiving, by the two or more receiver antennas of the receiver, an observed signal comprising the input signal and an additive noise term. The method can then form a data matrix using the observed signals from the two or more receiver antennas. The method can also include computing a singular value decomposition of the data matrix. The singular value decomposition can then be used to generate a parameter matrix. The method can then form a Toeplitz signal matrix using the parameter matrix. The method can estimating the input signal using the Toeplitz signal matrix.

Abstract: A method, non-transitory computer readable medium, and system for multiple-input multiple-output for blind identification that includes receiving an input signal, originated as an output signal of a transmitter, at a receiver. A signal processing module can obtain the input signal from the receiver. The signal processing module can use a finite impulse response filter and one or more matrices derived from the input signal to minimize a cost function and obtain a parameter matrix. The parameter matrix can then be used to estimate the output signal by generating one or more Toeplitz matrices using the parameter matrix.

Abstract: A process chamber housing for an additive manufacturing apparatus comprising a process chamber with a bottom, a ceiling, and sidewalls jointly enclosing a volume of the process chamber, with a gas inlet in a front wall and a gas outlet in a rear wall of the sidewalls. The gas inlet and outlet are positioned at opposite sides of an opening in the bottom and face each other, which allows for an improved removal of smoke out of the process chamber if the gas inlet has a width wi, the opening has a width ws, and the gas outlet has a width w0, such that at least one of the relations (i) wi?ws±4 cm and wo?ws±4 cm; (ii) wi?ws and/or wo?ws; and (iii) wi?ws+1 cm and/or wo?ws+1 cm is satisfied.

Abstract: An apparatus, a method, and a non-transitory computer readable medium for event detection of passive seismic data are disclosed. The apparatus includes processing circuitry extracts features from the passive seismic data based on a backbone subnetwork of a residual deep neural network. The processing circuitry generates bounding box proposals for a region of interest (ROI) in the passive seismic data based on the extracted features being input to a region proposal network of the residual deep neural network. The processing circuitry classifies the bounding box proposals into two groups. Each bounding box proposal in a first group indicates that a corresponding seismic signal presents in the ROI. Each bounding box proposal in a second group indicates that no seismic signal presents in the ROI. The processing circuitry determines at least one seismic signal in the ROI from the first group of bounding box proposals.

Abstract: A system, computer-readable storage medium and method of reflection seismic survey in a wireless seismic network within a survey area is described. The method includes detecting, in each of a plurality of wireless seismic sensor nodes, seismic reflection signals from a seismic energy source; recording, in each of a plurality of wireless geophones, detected seismic signals; transmitting, by the geophones, the recorded seismic signals as digital data, using a combination of Orthogonal Frequency-Division Multiple Access (OFDMA) and Time Division Multiple Access (TDMA), to a central data receiving device; changing the seismic energy source location for seismic reflection; and repeating the detecting, recording and transmitting a number of times for each change in seismic energy source.

Abstract: A geophone, and method for distributing geophones around a seismic data source are described. The geophone includes a housing, a spike provided on a bottom surface of the housing, a sensor configured to sense seismic data; a processor configured to process the seismic data, a transceiver configured to transmit the processed seismic data and receive radio frequency (RF) signals wirelessly; and a power device. The power device is coupled to the sensor, the processor and the transceiver. The power device is configured to harvest energy from an environment where the geophone is located. The power device includes a solar cell provided on a top surface of the housing, a piezoelectric system provided on an edge of the housing adjacent to the top surface, and a thermoelectric generator provided on a bottom surface of the housing and a surface of the spike.

Abstract: An apparatus, method, and non-transitory computer readable medium that can mitigate wireless channel impairments in seismic data transmission using deep neural networks is disclosed. The apparatus includes a receiving circuitry to receive seismic data and a processing circuitry. The processing circuitry is configured to apply a blind system identification process to the seismic data to estimate a channel impulse response of the seismic data, apply an optimum equalization process to obtain estimated seismic data based on the channel impulse response, process the estimated seismic data to generate processed seismic data, classify the processed seismic data into a first group of seismic data each of which has a signal-to-noise ratio (SNR) less than an SNR threshold and a second group of seismic data each of which has an SNR no less than the SNR threshold, and enhance the SNR of each of the first group of seismic signals.

Abstract: An apparatus including a process chamber accommodating a carrier for receiving a raw material powder. An irradiation device of the apparatus is configured to selectively irradiate electromagnetic or particle radiation onto the raw material powder on the carrier in order to produce a work piece by an additive layer construction method, wherein a transmission element allows the transmission of the electromagnetic or particle radiation into the process chamber. The apparatus further includes a gas inlet and a gas outlet for supplying and discharging gas to and from the process chamber which are configured to generate a protective gas stream for protecting the transmission element from being contaminated by impurities present in the process chamber. The gas inlet includes a gas permeable, porous component forming a gas inlet area.

Abstract: We describe a process chamber, an apparatus, a modular system, a method, a safety device, a positioning system and a system for producing a three-dimensional workpiece and/or for use thereof when producing a three-dimensional workpiece. The process chamber for producing the three-dimensional workpiece via an additive layer construction method comprises: a material supply unit comprising a substantially ring-like shaped end portion at a first side of the process chamber, wherein the material supply unit is adapted to supply, via the end portion, material to a carrier on which the material is to be processed by the process chamber for producing the three-dimensional workpiece, and an opening at the first side of the process chamber for processing, by the process chamber, the material supplied on the carrier in order to produce the three-dimensional workpiece, wherein the substantially ring-like shaped end portion surrounds the opening.

Abstract: A process chamber housing for an additive manufacturing apparatus comprising a process chamber with a bottom, a ceiling, and sidewalls jointly enclosing a volume of the process chamber, with a gas inlet in a front wall and a gas outlet in a rear wall of the sidewalls. The gas inlet and outlet are positioned at opposite sides of an opening in the bottom and face each other, which allows for an improved removal of smoke out of the process chamber if the gas inlet has a width wi, the opening has a width ws, and the gas outlet has a width w0, such that at least one of the relations (i) wi?ws±4 cm and w0?ws±4 cm; (ii) wi?ws and/or w0?ws; and (iii) wi?ws+1 cm and/or w0?ws+1 cm is satisfied.

Abstract: A data-driven linear filtering method to recover microseismic signals from noisy data/observations based on statistics of background noise and observation, which are directly extracted from recorded data without prior statistical knowledge of the microseismic source signal. The method does not depend on any specific underlying noise statistics and works for any type of noise, e.g., uncorrelated (random/white Gaussian), temporally correlated and spatially correlated noises. The method is suitable for microquake data sets that are recorded in contrastive noise environments. The method is demonstrated with both field and synthetic data sets and shows a robust performance.

Abstract: Penetration-resistant composites and methods of forming penetration-resistant composites are described herein. The penetration-resistant composites include a woven or non-woven substrate; and an elastomeric binder covering at least a portion of the substrate. The elastomeric binder includes a polymeric base and particles dispersed within the polymeric base. The particles include one or more of amorphous silica particles, fumed silica particles, boron nitride particles, calcium chloride particles, aluminum oxide particles, calcium carbonate particles, graphite particles, metallic glass particles and silicon carbide particles. The particles have a concentration in a range of about 0 wt. % to about 80 wt. % of the elastomeric binder and have a size in a range of about 1 nanometers to 100 micrometers.

Abstract: A system and method and non-transitory computer readable medium method for filtering signals representative of microseismic events with an infinite impulse response (IIR) Wiener filter which precludes the need for statistics or prior knowledge of the signal of interest. The second-order statistics of the noise and the noisy data are extracted from the recorded data only. The criteria used to optimize the filter impulse response is the minimization of the mean square error. The IIR Wiener filter was tested on synthetic and field data sets and found to be effective in denoising microseismic data with low SNR (?2 dB).

Abstract: A method and apparatus for equalization in a communication system. The method includes receiving an input of a block of symbols, filtering the input in the frequency domain, calculating an error factor in the time domain based on the filtered input, updating tap weights of the equalizer in the frequency domain using circular correlation based on the error factor and the conjugate of the input in the frequency domain, and outputting the filtered input.

Abstract: A method and apparatus for equalization in a communication system. The method includes receiving an input of a block of symbols, filtering the input in the frequency domain, calculating an error factor in the time domain based on the filtered input, updating tap weights of the equalizer in the frequency domain using circular correlation based on the error factor and the conjugate of the input in the frequency domain, and outputting the filtered input.

Abstract: An apparatus including a process chamber accommodating a carrier for receiving a raw material powder. An irradiation device of the apparatus is configured to selectively irradiate electromagnetic or particle radiation onto the raw material powder on the carrier in order to produce a work piece by an additive layer construction method, wherein a transmission element allows the transmission of the electromagnetic or particle radiation into the process chamber. The apparatus further includes a gas inlet and a gas outlet for supplying and discharging gas to and from the process chamber which are configured to generate a protective gas stream for protecting the transmission element from being contaminated by impurities present in the process chamber. The gas inlet includes a gas permeable, porous component forming a gas inlet area.

Abstract: The application relates to a device for producing three-dimensional workpieces, the device including: a structural surface designed to receive a molding compound; and an irradiation arrangement designed to selectively irradiate the molding compound on the structural surface with electromagnetic radiation, in order to produce a workpiece by means of generative layer construction, where the irradiation device comprises a plurality of irradiation units, the irradiation units being designed to irradiate an individual region of the structural surface respectively associated with the irradiation units, and where the beams emitted by the irradiation units respectively have a cross-sectional surface corresponding to between approx. 2% and approx. 170% of the surface of the respectively associated individual region. The application also relates to the use of such a device and to a method for producing three-dimensional workpieces by means of such a device.