Abstract: Examples associated with user authentication are described. One example method includes authenticating a user of a device using a static authentication technique. A behavior profile associated with the user is loaded. The behavior profile describes a pattern of device usage behavior by the user in a three-dimensional space over a time slice. The behavior profile also identifies distinctive user habits. Usage of the device is monitored, and a behavior similarity index is periodically updated. The behavior similarity index describes a similarity between the usage of the device and the pattern of device usage behavior. The behavior similarity index is weighted based on the distinctive user habits. Access to the device is restricted when the behavior similarity index reaches a predefined threshold.

Abstract: Systems and methods for providing a non-rewritable code comparator using a memristor and a serial resistor are disclosed. An example apparatus comprises: a plurality of first terminals; a plurality of second terminals; and a plurality of two-terminal device pairs formed between the plurality of first terminals and the plurality of second terminals. Each two-terminal device pair in the plurality of two-terminal device pairs include at least one memristor and at least one resistor; each two-terminal device pair is configured to be switched to a subsequent state once and only once. In some implementations, a two-terminal device pair is configured to remain in the subsequent state regardless of whether an input signal to the apparatus matches a reference signal to the apparatus.

Abstract: Technologies relating to crossbar array circuits with parallel grounding lines are disclosed. An example crossbar array circuit includes: a word line; a bit line; a first selector line; a grounding line; a first transistor including a first source terminal, a first drain terminal, a first gate terminal, and a first body terminal; and an RRAM device connected in series with the first transistor. The grounding line is connected to the first body terminal and is grounded and the grounding line parallel to the bit line. The first selector line is connected to the first gate terminal. In some implementations, the RRAM device is connected between the first transistor via the first drain terminal and the word line, and the first source terminal is connected to the bit line.

Abstract: According to an example, an apparatus may include a printhead to deliver a printing liquid from firing chambers through a plurality of bores arranged along a surface of the printhead. The apparatus may also include a cleaning system to apply a pressurized cleaning fluid onto the surface of the printhead while preventing application of the pressurized cleaning fluid into the firing chambers through the plurality of bores.

Abstract: In one example In accordance with the present disclosure, a fluid ejection device is described. The fluid ejection device Includes a number of nozzles to eject fluid. Each nozzle Includes multiple firing chambers to hold fluid. The multiple firing chambers are separated: by a chamber partition. Each nozzle also includes a shared nozzle orifice in a substrate through which to dispense fluid. Each nozzle also Includes multiple ejectors, at least one ejector disposed in each firing chamber, in a common channel of the nozzle, fluid from the multiple firing chambers Is mixed, A height of the common channel is defined by the substrate and the chamber partition and is less than a width of the shared nozzle orifice.

Abstract: Systems and methods for reducing column switch resistance error RRAM-based crossbar array circuits are disclosed. An example crossbar array circuit includes: a crossbar array including a row wire, a column wire, and a cross-point device connected between the row wire and the column wire; a column switch having a column switch input and a column switch output, connected to the cross-point device; an Op-amp device having a non-inverting input, an inverting input, and an Op-amp output; a three-terminal switch having a first terminal, a second terminal, and a third terminal. The three-terminal switch is connected to the inverting input and is configured to switch between the column switch input and the column switch output; a load resistor is connected with the column switch output and the Op-amp output.

Abstract: According to an example, an apparatus may include an agent delivery device to selectively deliver an agent onto a layer of build material particles. The apparatus may also include an energy source to apply energy onto the layer of build material particles to selectively fuse the build material particles in the layer based upon the locations at which the agent was delivered and a chamber formed of a plurality of walls, in which the agent delivery device and the energy source are housed inside the chamber. The apparatus may further include a vapor source to supply vapor into the chamber to wet the build material particles inside the chamber.

Abstract: Technologies relating to implementing two-stage ramp ADCs in crossbar array circuits for high performance matrix multiplication are disclosed. An example two-stage ramp ADC includes: a transimpedance amplifier configured to convert an input signal from current to voltage; a comparator connected to the transimpedance amplifier; a switch bias set connected to the comparator; a switch side capacitor in parallel with the switch bias set; a ramp side capacitor in parallel with the switch bias set; a ramp generator connected to the comparator via the ramp side capacitor, wherein the ramp generator is configured to generate a ramp signal; a counter; and a memory connected to the comparator, wherein the memory is configured to store an output of the comparator.

Abstract: Technologies relating to controlling forming process in RRAM devices implemented in a cross-bar circuit using one or more feedback circuits are disclosed. An example apparatus includes an RRAM cell configured to form a channel; a MOSFET having a drain terminal, a source terminal, and a gate terminal, wherein the MOSFET is connected to the RRAM cell via the drain terminal; a TIA connected to the MOSFET via the source terminal; a first signal generator connected to the RRAM cell; a second signal generator connected to the MOSFET via the gate terminal; and a comparator having a first input end, a second input end, and an output end, wherein the comparator is connected to the TIA via the first input end, the second input end is connected to a reference voltage source, and the output end is connected to the first signal generator and the second signal generator.

Abstract: Technologies relating to crossbar array circuits with nTnR design to reduce sneak current path and minimize area size are disclosed. An example crossbar array circuit includes: a first transistor comprising a first source terminal, a first drain terminal and a first gate terminal; a first RRAM device connected to the first source terminal of the first transistor; a second transistor comprising a second source terminal, a second drain terminal and a second gate terminal; a second RRAM device connected to the second source terminal of the second transistor; a word line connected to the first drain terminal of the first transistor and the second drain terminal of the second transistor; a first bit line connected to the first RRAM device; and a second bit line connected to the second RRAM device, wherein the first gate terminal of the first transistor is configured to be connected to a first selective voltage source, and the second gate terminal is configured to be connected to a second selective voltage source.

Abstract: Technologies relating to crossbar array circuits with proton-based two-terminal volatile memristive devices are disclosed. An example apparatus includes: a first bottom conductive layer, a first switching oxide layer formed on the first bottom conductive layer, a first top conductive layer formed on the first switching oxide layer, an intermediate layer formed on the first top conductive layer, a second bottom conductive layer formed on the intermediate layer, a second oxide layer whose conductance can be modulated by H-dopant formed on the second bottom conductive layer; and a proton reservoir layer formed on the second oxide layer, wherein the second bottom conductive layer is H-doped.

Abstract: Technologies relating to analog-to-analog quantizers with an intrinsic Rectified Linear Unit (ReLU) function designed for in-memory computing are disclosed. An apparatus, in some implementations, includes: a DAC; a first crossbar connected to the DAC; a first analog quantizer connected to the first crossbar; a buffer connected to the first analog quantizer; a second crossbar connected to the buffer; and an ADC connected to the second crossbar.

Abstract: According to an example, a three-dimensional (3D) printer may include a first delivery device to selectively deposit a fusing agent onto a layer of build materials and a second delivery device to deposit coolant droplets at tuned drop weights onto the layer of build materials. The 3D printer may also include a controller to control the second delivery device to selectively deposit the coolant droplets at the tuned drop weights onto selected areas of the build material layer, in which the drop weights of the selectively deposited coolant droplets are tuned to provide a thermal balance between multiple areas of the build material layer during application of fusing radiation onto the build material layer.

Abstract: Apparatus, systems, articles of manufacture, and methods to facilitate capacitive code comparing are disclosed. An example apparatus includes a comparator to receive a first portion of a first input and a second portion of a second input, the comparator including a capacitor. The example apparatus further includes a peripheral determination circuit to cause the capacitor to couple the first portion to the second portion; in response to coupling the first portion to the second portion, ground the capacitor; sense a current discharged by the grounded capacitor; and determine a Hamming distance of the first input and the second input based on the sensed current discharged by the capacitor.

Abstract: Technologies relating to crossbar array circuits with parallel grounding lines are disclosed. An example crossbar array circuit includes: a word line; a bit line; a first selector line; a grounding line; a first transistor including a first source terminal, a first drain terminal, a first gate terminal, and a first body terminal; and an RRAM device connected in series with the first transistor. The grounding line is connected to the first body terminal and is grounded and the grounding line parallel to the bit line. The first selector line is connected to the first gate terminal. In some implementations, the RRAM device is connected between the first transistor via the first drain terminal and the word line, and the first source terminal is connected to the bit line.

Abstract: A surface enhanced luminescence (SEL) sensor may include a substrate and nano fingers extending from the substrate. In one implementation, the nano fingers may be arranged in a cluster of at least three nano fingers extending from the substrate. The nano fingers of the cluster having different geometries so as to bend into a closed state such that each of the nano fingers of the cluster are linked to one another.

Abstract: A dual-purpose calibration system for an optical pressure sensitive paint considering static and sinusoidal pressure changes, and a calibration method, in which a dual-purpose calibration tube is used in common, are provided. In the dual-purpose calibration system, a dynamic adapter and a static adapter are replaced with each other to achieve switching between dynamic calibration and static calibration, so that two calibration methods, one static and the other dynamic, can be implemented by the dual-purpose calibration system. The switching between the dynamic calibration and the static calibration includes changing between the dynamic adapter and static adapter, and setting a sound source corresponding to the dynamic adapter or setting a gas source corresponding to the static adapter.

Abstract: One example of a device includes an antenna, a memristor code comparator, and a controller. The antenna is to receive a wake up signal. The memristor code comparator is to compare the wake up signal to a reference signal. The controller is to provide a trigger signal to wake up the device in response to the wake up signal matching the reference signal.

Abstract: In some examples, a micro light-emitting diode (?LED) panel may include a ?LED including at least two electrodes (or bond pads), and a ferromagnetic material included in the at least two electrodes (or bond pads) and/or disposed on the at least two electrodes (or bond pads). The ?LED panel may further include a panel substrate including ferromagnetic material selectively disposed at least at two locations corresponding to locations of the at least two electrodes (or bond pads) to align a plurality of ?LEDs including the ?LED onto the panel substrate.

Abstract: According to examples, an apparatus may include a printhead assembly containing a housing supporting a printhead. The printhead may have nozzles that are to fire droplets of a functional agent onto a layer of build material particles along respective flight paths to form sections of a 3D object from the build material particles, an array of light emission devices to direct respective light beams in the respective flight paths, and an array of photon detectors to detect respective light beams directed from a light source of the array of light emission devices, the light emission devices and the photon detectors being supported on the housing. The apparatus may also include a controller to determine whether any of the nozzles is operating improperly based upon whether the photon detectors detected the light beams and to output an instruction regarding an improperly operating nozzle in response to a determination that the nozzle is operating improperly.