Abstract: A first pulsed beam of charged particles from a particle accelerator is accelerated toward a first target that is configured to emit a fast neutron beam in response to being struck by an accelerated particle such that the fast neutron beam is directed toward a physical region. The last neutron beam includes a neutron having an energy sufficient to cause fission in a fissionable material. Data from a sensor configured to detect radiation of a fission product is accessed, and before accelerating a second pulsed beam of charged particles, whether the physical region includes a fissionable material based on the data from the sensor is determined.

Abstract: A method of fabricating a frontside-illuminated inverted quantum well infrared photodetector may include providing a quantum well wafer having a bulk substrate layer and a quantum material layer, wherein the quantum material layer includes a plurality of alternating quantum well layers and barrier layers epitaxially grown on the bulk substrate layer. The method further includes applying at least one frontside common electrical contact to a frontside of the quantum well wafer, bonding a transparent substrate to the frontside of the quantum well wafer, thinning the bulk substrate layer of the quantum well wafer, and etching the quantum material layer to form quantum well facets that define at least one pyramidal quantum well stack. A backside electrical contact may be applied to the pyramidal quantum well stack. In one embodiment, a plurality of quantum well stacks is bonded to a read-out integrated circuit of a focal plane array.

Abstract: A method of fabricating a frontside-illuminated inverted quantum well infrared photodetector may include providing a quantum well wafer having a bulk substrate layer and a quantum material layer, wherein the quantum material layer includes a plurality of alternating quantum well layers and barrier layers epitaxially grown on the bulk substrate layer. The method further includes applying at least one frontside common electrical contact to a frontside of the quantum well wafer, bonding a transparent substrate to the frontside of the quantum well wafer, thinning the bulk substrate layer of the quantum well wafer, and etching the quantum material layer to form quantum well facets that define at least one pyramidal quantum well stack. A backside electrical contact may be applied to the pyramidal quantum well stack. In one embodiment, a plurality of quantum well stacks is bonded to a read-out integrated circuit of a focal plane array.

Abstract: A first multi-dimensional digital image of a scan region is generated. The scan region is included in a materials-detection apparatus and is configured to receive and move containers through the materials-detection apparatus. A pre-defined background range of values is accessed, the background range of values representing a range of values associated with non-target materials and the background range of values being distinct from values associated with the target materials. A value of a voxel included in the multi-dimensional digital image is compared to the background range of values to determine whether the value of the voxel is within the background range of values. If the value of the voxel is within the background range of values, the voxel is identified as a voxel representing a low-density material. A second multi-dimensional digital image that disregards the identified voxel is generated to compress the first multi-dimensional digital image.

Abstract: An active electronically steered cathode (AESC) applies one or more electromagnetic modes to an input cavity, similar to that used in an inductive output tube. The structure and superposition of these modes creates local electric field maxima, causing the electron emission site or sites to move or be distributed across the surface of the cathode. Changing the amplitude, phase, or frequency of the modes provides time-variable control of the electric field profile, thereby generating electronically steered electron beams. One embodiment employs a pair of orthogonal TM modes driven out of phase, causing the electric field maximum to rotate around an annular cathode, producing a helical beam. Slots in the control grid may be used to segment the helical beam into discrete bunches to provide additional density modulation.

Abstract: An electric drive unit for a motor vehicle includes an electric motor having a stator that is fixed with respect to a stub axle and a rotor that is rotatably supported with respect to the stub axle. A gear system has its input connected to the rotor for torque transmission. A wheel carrier is connected to the output of the gear system for torque transmission. A first bearing of the wheel carrier is provide on a first axial side of the electric motor facing away from the gear system. A second bearing of the wheel carrier is provided either on the first axial side of the electric motor, or in the gear system, realized in the form of a bearing of a rotatable gear system part connected to the wheel carrier.

Abstract: A device having an encryption module in communication with first and second communication ports may facilitate connecting to an access network, without requiring a non-secure hard drive to initiate the network access. The encryption module may define a normal mode and a bypass mode. In normal mode, data from the first port may be sent encrypted to the second port, for communicating securely in an encrypted environment. In bypass mode, data from the first port may be sent unencrypted to the second port. The data being sent may be intercepted and presented to the user for approval in a human readable format. The user may confirm that the data is appropriate for being sent unencrypted. This data may be sent unencrypted in response to a request for information (e.g., an assent to terms and conditions) from the access network, such as at a hotel or public wireless hotspot, for example.

Abstract: A training set including a target object set and a clutter object set is accessed. It is determined that the training set includes multiple types of targets or multiple types of clutter. The target feature value of a type of target is compared with the clutter feature value. The type of target is associated with the non-target object based on the comparison. A classifier is trained using the target feature value and the clutter feature value of the associated type of target and the non-clutter object. A feature value associated with an unknown object is applied to multiple classifiers to generate a set of metrics for the unknown object. The metrics are aggregated into an overall metric. Whether the unknown object is included in the target set is determined based on the overall metric.

Abstract: Screening of items for the presence of contaminants, such as explosives residue, is accomplished by subjecting an item loaded into a pressure chamber to a pressure substantially in excess of atmospheric pressure conditions and rapidly decompressing the item to the ambient atmospheric pressure. The rapid decompression serves to scavenge vapors and particles from the exterior and interior of the item and any objects it contains. A sample of the vapors and particles removed from the item by the rapid decompression is sampled and is tested to determine whether a predetermined contaminant is present in the sample. Depending on the types of contaminants for which the sample is tested, it is possible to detect whether explosives, biological or chemical agents, and/or narcotics residues are present on or in the item being screened.

Abstract: A multi-channel imaging device is provided. The multi-channel imaging device includes a focal plane array having an array of pixels configured to detect radiation in a predetermined wavelength band. Subsets of the array of pixels are arranged to define a plurality of unit cell image areas. The multi-channel imaging device also includes a lens array having a plurality of lens elements configured to image a scene onto the plurality of unit cell image areas. The lens elements and the unit cell image areas define a plurality of unit cells having at least one lens element and at least one unit cell image area. Each of the plurality of unit cells is configured to create a complete image of the scene. Additionally, a plurality of unit cell filters corresponding to the plurality of unit cells is configured to filter radiation such that each unit cell is dedicated to an image channel is also provided.

Abstract: Interferometric angle-of-arrival (AOA) ambiguities due to local multipath reflections are resolved by measuring the received phase differences of one or more pairs of antenna elements of the interferometer array, constructing hypotheses from unwrapped phase pairs that correspond to potential AOA solutions, and selecting the hypothesis that most likely represents the true AOA of the signal emitter based on processed unwrapped data that has been corrected through the application of a priori calibration terms selected on the bases of the candidate hypotheses.

Abstract: Techniques for efficient upconversion can process complex input data, such as for example data in an inphase and quadrature form. Half sample interpolation filtering and delay can be performed, and the results can be combined in a quarter-rate upconverter. The quarter rate upconversion can allow one of the half-sample interpolating filtering and the delay to be performed on one of either the inphase and quadrature samples.

Abstract: In one general aspect, a sample area is energized. A thermal energy status of the sample area is monitored. The thermal energy status including at least one of a radiant energy and a temperature. A thermal signature of a region included in the sample area is determined based on the thermal energy status of the region. The thermal signature is analyzed to determine whether explosive particles are included in the region.

Abstract: An integrated mine detection system includes a ground penetrating metal detector and a ground penetrating radar detector. The integrated mine detection system includes an integrated search device housing a radio-wave transmitter of the radar detector and a coil of the metal detector. The radio-wave transmitter includes an antenna. The integrated search device includes a radio-wave receiver in the form of a pair of receiving antennas.

Abstract: Methods and terminals can use Internet Protocol (IP) packets for waveform independent contention access in a hub-spoke network. In some embodiments, a spoke terminal can transmit a link allocation packet on an uplink when the uplink is available and the spoke terminal has data to transmit. The link allocation packet can be embedded within an IP packet. When the spoke terminal receives the link allocation packet on the downlink, the spoke terminal can transmit one or more IP packets with data, followed by a link release packet. The link release packet can be embedded within an IP packet.

Abstract: A device includes a sensing element configured to produce a representation of an object in a space near the sensing element, an electronic storage comprising multiple representations, each representation being associated with a particular object, a communications interface, and a processor operable to receive the representation of the object in the space from the sensing element, compare the representation of the object in the space to the multiple representations stored in the electronic storage, determine that the representation of the object in the space is different from all of the multiple representations based on the comparison, identify the representation as a new representation based on the determination, and cause the new representation to be available to a data site through the communications interface. The device also may obtain a new representation from the data site.

Abstract: A dual energy inspection system that generates X-rays with an electron beam scanned over targets. A switchable voltage source that can be change its voltage output may cause X-rays to be generated at different energies. This X-ray generation subsystem is controlled by a sequencer that provides beam steering and shaping control inputs that may be dependent on the voltage provided by the voltage source. In another aspect, the dual energy inspection system may use multiple types of detectors, each sensitive to X-rays of a different energy. A relatively small number of detectors sensitive to one energy level is provided. Nonetheless, dual energy measurements may be made on objects within an item under inspection by identifying points that, for each object of interest, provide a low interference path to one of those detectors. Measurements made with radiation emanating from those points are used for dual energy analysis of those objects.

Abstract: An object within a region is exposed to a first beam of penetrating radiation. The first beam of penetrating radiation is sensed on a side opposite the region from a source of the first beam. An attenuation of the first beam caused by passing the first beam through the object is determined, the attenuation is compared to a threshold attenuation. If the attenuation exceeds the threshold attenuation, a parameter of a second of beam of penetrating radiation is adjusted based on the determined attenuation.

Abstract: A technique for decoding low-density parity check codes includes performing a combined check node and variable node calculation. Decoding is initialized using channel likelihood values estimated from a received physical signal. The decoding iteratively updates the variable nodes. Performing a combined check node and variable node calculation can enable reduced memory usage and faster convergence for the decoder.

Abstract: A handheld communications device is created with a touch sensitive display, a secure computing component, and a non-secure computing component. The secure component may comprise a secure CPU executing a secure operating system. The non-secure component may comprise a separate non-secure CPU executing a separate non-secure operating system. The touch sensitive display on the handheld communications device is divided into a secure portion and a non-secure portion such that information displayed in the secure portion is provided by the secure operating system, and information displayed in the non-secure portion is provided by the non-secure operating system. Similarly, data entered through the secure portion of the display is provided to the secure operating system, and data entered through the non-secure portion of the display is provided to the non-secure operating system.