Abstract: The present disclosure relates to a neuromorphic neuron apparatus comprising an output generation block and at least one adaptation block. The apparatus has a current adaptation state variable corresponding to previously generated one or more signals. The output generation block is configured to use an activation function for generating a current output value based on the current adaptation state variable. The adaptation block is configured to repeatedly: compute an adaptation value of its current adaptation state variable using the current output value and a correction function; use the adaption value to update the current adaptation state variable to obtain an updated adaptation state variable, the updated adaptation state variable becoming the current adaptation state variable; receive a current signal; and cause the output generation block to generate a current output value based on the current adaptation state variable and input value that obtained from the received signal.

Abstract: Embodiment of the invention are directed to transmitting signals between neurons of a hardware-implemented, spiking neural network (or SNN). The network includes neuronal connections, each including a synaptic unit connecting a pre-synaptic neuron to a post-synaptic neuron. Spikes received from the pre-synaptic neuron of said each neuronal connection are first modulated, in frequency, based on a synaptic weight stored on said each synaptic unit, to generate post-synaptic spikes, such that a first number of spikes received from the pre-synaptic neuron are translated into a second number of post-synaptic spikes. At least some of the spikes received from the pre-synaptic neuron may, each, be translated into a train of two or more post-synaptic spikes. The post-synaptic spikes generated are subsequently transmitted to the post-synaptic neuron of said each neuronal connection. The novel approach makes it possible to obtain a higher dynamic range in the synapse output.

Abstract: This invention relates to an apparatus, system, and method for computing with neuromorphic circuit architectures that have neurons with interconnected internal state information. The interconnected internal state information allows the neurons to enable or strengthen the input to other neurons. Furthermore, neuron internal state information provides insights on the characteristics of the input data that can be used to enhance the performance of the neuromorphic system. The neuromorphic system can be implemented with an artificial phase-change-based neurons.

Abstract: A neuromorphic neuron apparatus includes an accumulation block and an output generation block. The apparatus has a current state variable corresponding to previously received one or more signals. The output generation block is configured to use an activation function for generating a current output value based on the current state variable. The accumulation block is configured to repeatedly: compute an adjustment of the current state variable using the current output value and a correction function indicative of a decay behaviour of a time constant of the apparatus; receive a current signal; update the current state variable using the computed adjustment and the received signal, the updated state variable becoming the current state variable; and cause the output generation block to generate a current output value based on the current state variable.

Abstract: A method according to one embodiment includes applying a static head skew to a magnetic tape head, positioning the first reader at a first y-position relative to a servo pattern in a servo band, and measuring y-positions of the second reader relative to the servo pattern in the servo band while the first reader is at the first y-position. A y-position value is calculated for the second reader based on the measured y-positions. The following process is repeated several times: moving the first reader to a next y-position, measuring y-positions of the second reader while the first reader is at the next y-position, and calculating a y-position value of the second reader based on the measured y-position of the second reader. A unique nonlinearity value of the servo pattern in the servo band is calculated for each of the calculated y-position values of the second reader.

Abstract: A method according to one embodiment includes generating a y-position estimate based on a servo readback signal, and determining a nonlinearity-correction value corresponding to the y-position estimate. The method further includes adjusting the y-position estimate using the nonlinearity-correction value. A computer program product for compensating for nonlinearity in a timing based servo pattern according to another embodiment includes a computer readable storage medium having program instructions embodied therewith. The program instructions are readable and/or executable by a controller to cause the controller to perform the foregoing method. An apparatus according to another embodiment includes a controller configured to perform the foregoing method.

Abstract: Embodiments relate to a neuromorphic architecture for unsupervised feature learning using memristive synapses realized using phase-change devices. A spiking neural network architecture for unsupervised pattern learning and a spike-based learning algorithm compatible with phase-change synapses is described, and a feature-learning algorithm capable of performing a sequence of set operations on input patterns is provided. A learning rule for the extraction of certain features of the input that is compatible with spiking neurons and synapses with spike-based plasticity is also provided. The system enables enhanced pattern- and feature-extraction capabilities in neuromorphic systems.

Abstract: A sensor arrangement for position sensing comprises a row of multiple magnetoresistive elements. A magnetic field source (3) provides a magnetic field with a first magnetic pole (N) and a second magnetic pole (S). The magnetic field source (3) is arranged such that magnetoresistive elements of the row face one of: the first magnetic pole (N) or second magnetic pole (S). The first magnetoresistive element is arranged in the magnetic field and provides a first output signal dependent on a position of the magnetoresistive element relative to the magnetic field source (3). A measurement unit is configured to determine a position of the magnetic field source (3) relative to the magnetoresistive elements of the row dependent on the first output signals of the magnetoresistive elements.

Abstract: A method according to one embodiment includes generating a y-position estimate based on a servo readback, and determining a nonlinearity-correction value corresponding to the y-position estimate. The method further includes adjusting the y-position estimate using the nonlinearity-correction value. A computer program product for compensating for nonlinearity in a timing based servo pattern according to another embodiment includes a computer readable storage medium having program instructions embodied therewith. The program instructions are readable and/or executable by a controller to cause the controller to perform the foregoing method. An apparatus according to another embodiment includes a controller configured to perform the foregoing method.

Abstract: A method according to one embodiment includes applying a static head skew to a magnetic tape head, positioning the first reader at a first y-position relative to a servo pattern in a servo band, and measuring y-positions of the second reader relative to the servo pattern in the servo band while the first reader is at the first y-position. A y-position value is calculated for the second reader based on the measured y-positions. The following process is repeated several times: moving the first reader to a next y-position, measuring y-positions of the second reader while the first reader is at the next y-position, and calculating a y-position value of the second reader based on the measured y-position of the second reader. A unique nonlinearity value of the servo pattern in the servo band is calculated for each of the calculated y-position values of the second reader.

Abstract: A sensor arrangement for position sensing comprises a magnetic field source and a magnetoresistive element arranged in a magnetic field generated by the magnetic field source, which magnetoresistive element provides an output signal (R) dependent on a position (x) of the magnetoresistive element relative to the magnetic field source. A feedback controller is configured to receive the output signal (R) of the magnetoresistive element and is configured to adjust one or more of the position (x) of the magnetoresistive element relative to the magnetic field source and a strength of the magnetic field generated by the magnetic field source acting on the magnetoresistive element dependent on the output signal (R) of the magnetoresistive element.

Abstract: A resistive memory cell is connected in circuitry which has a first input terminal for applying neuron input signals including a read portion and a write portion. The circuitry includes a read circuit producing a read signal dependent on resistance of the memory cell, and an output terminal providing a neuron output signal, dependent on the read signal in a first state of the memory cell. The circuitry also includes a storage circuit storing a measurement signal dependent on the read signal, and a switch set operable to supply the read signal to the storage circuit during application of the read portion of each neuron input signal to the memory cell, and, after application of the read portion, to apply the measurement signal in the apparatus to enable resetting of the memory cell to a second state.

Abstract: Artificial neuron apparatus includes first and second resistive memory cells. The first resistive memory cell is connected in first circuitry having a first input and output. The second resistive memory cell is connected in second circuitry having a second input and output. The first and second circuitry are operable in alternating read and write phases to apply a programming current to their respective memory cells on receipt of excitatory and inhibitory neuron input signals, respectively. During the write phase, resistance of the respective cells is changed in response to successive excitatory and inhibitory neuron input signals. During the read phase, a read current is applied to their respective cells to produce first and second measurement signals, respectively. An output circuit connected to the first and second outputs produces a neuron output signal at a neuron output when a difference between the first and second measurement signals traverses a threshold.

Abstract: Artificial neuron apparatus includes first and second resistive memory cells. The first resistive memory cell is connected in first circuitry having a first input and output. The second resistive memory cell is connected in second circuitry having a second input and output. The first and second circuitry are operable in alternating read and write phases to apply a programming current to their respective memory cells on receipt of excitatory and inhibitory neuron input signals, respectively. During the write phase, resistance of the respective cells is changed in response to successive excitatory and inhibitory neuron input signals. During the read phase, a read current is applied to their respective cells to produce first and second measurement signals, respectively. An output circuit connected to the first and second outputs produces a neuron output signal at a neuron output when a difference between the first and second measurement signals traverses a threshold.

Abstract: A sensor arrangement for position sensing comprises a row of multiple magnetoresistive elements. A magnetic field source (3) provides a magnetic field with a first magnetic pole (N) and a second magnetic pole (S). The magnetic field source (3) is arranged such that magnetoresistive elements of the row face one of: the first magnetic pole (N) or second magnetic pole (S). The first magnetoresistive element is arranged in the magnetic field and provides a first output signal dependent on a position of the magnetoresistive element relative to the magnetic field source (3). A measurement unit is configured to determine a position of the magnetic field source (3) relative to the magnetoresistive elements of the row dependent on the first output signals of the magnetoresistive elements.

Abstract: In one general embodiment, a method includes applying a static head skew to a magnetic tape head, positioning the first reader at a first y-position relative to a servo pattern in a servo band, measuring y-positions of the second reader relative to the servo pattern in the servo band while the first reader is at the first y-position, and averaging the measured y-positions. The method further includes repeating the following process several times: moving the first reader to a next y-position, measuring y-positions of the second reader while the first reader is at the next y-position, and averaging the y-positions measured by the second reader while the first reader is at the next y-position. The method further includes calculating a unique nonlinearity value of the servo pattern in the servo band for each of the average y-position values, and storing and/or outputting the calculated nonlinearity values.

Abstract: Embodiments of the present invention provide a tape transport control system with enhanced regulation of tape tension and velocity over the entire length of the tape. The tape transport control system comprises of circuitry adapted to output and circuitry adapted to receive one or more signals representing a tape velocity, at least one radius of either the first tape reel or the second tape reel, and a tape tension, and based on the received signals, generate at least one control signal to control at least one of the first reel motor or the second reel motor so as to reduce a tension disturbance at a minimum, one frequency corresponding to a time-varying reel-rotation frequency, based on controller parameters that depend on the tape velocity and on the at least one radius of either the first tape reel or the second tape reel.

Abstract: A resistive memory cell is connected in circuitry which has a first input terminal for applying neuron input signals including a read portion and a write portion. The circuitry includes a read circuit producing a read signal dependent on resistance of the memory cell, and an output terminal providing a neuron output signal, dependent on the read signal in a first state of the memory cell. The circuitry also includes a storage circuit storing a measurement signal dependent on the read signal, and a switch set operable to supply the read signal to the storage circuit during application of the read portion of each neuron input signal to the memory cell, and, after application of the read portion, to apply the measurement signal in the apparatus to enable resetting of the memory cell to a second state.

Abstract: A method according to one embodiment includes generating a y-position estimate based on a servo readback signal from a servo reader reading a servo band, retrieving or calculating a nonlinearity-correction value corresponding to the y-position estimate, adjusting the y-position estimate using the nonlinearity-correction value, and outputting the adjusted y-position estimate. A computer program product for compensating for nonlinearity in a timing based servo pattern according to one embodiment includes a computer readable storage medium having program instructions embodied therewith. The computer readable storage medium is not a transitory signal per se. The program instructions are readable and/or executable by a controller to cause the controller to perform the foregoing method.

Abstract: A neuromorphic synapse with a resistive memory cell connected in circuitry having first and second input terminals. The input terminals respectively receive pre-neuron and post-neuron action signals, each having a read portion and a write portion, in use. The circuitry includes an output terminal for providing a synaptic output signal which is dependent on resistance of the memory cell. The circuitry is configured such that the synaptic output signal is provided at the output terminal in response to application at the first input terminal of the read portion of the pre-neuron action signal, and such that a programming signal, for programming resistance of the memory cell, is applied to the cell in response to simultaneous application of the write portions of the pre-neuron and post-neuron action signals at the first and second input terminals respectively. The synapse can be adapted for operation with identical pre-neuron and post-neuron action signals.