3,194 research outputs found
Neural-network dedicated processor for solving competitive assignment problems
A neural-network processor for solving first-order competitive assignment problems consists of a matrix of N x M processing units, each of which corresponds to the pairing of a first number of elements of (R sub i) with a second number of elements (C sub j), wherein limits of the first number are programmed in row control superneurons, and limits of the second number are programmed in column superneurons as MIN and MAX values. The cost (weight) W sub ij of the pairings is programmed separately into each PU. For each row and column of PU's, a dedicated constraint superneuron insures that the number of active neurons within the associated row or column fall within a specified range. Annealing is provided by gradually increasing the PU gain for each row and column or increasing positive feedback to each PU, the latter being effective to increase hysteresis of each PU or by combining both of these techniques
Analog hardware for delta-backpropagation neural networks
This is a fully parallel analog backpropagation learning processor which comprises a plurality of programmable resistive memory elements serving as synapse connections whose values can be weighted during learning with buffer amplifiers, summing circuits, and sample-and-hold circuits arranged in a plurality of neuron layers in accordance with delta-backpropagation algorithms modified so as to control weight changes due to circuit drift
Analog hardware for learning neural networks
This is a recurrent or feedforward analog neural network processor having a multi-level neuron array and a synaptic matrix for storing weighted analog values of synaptic connection strengths which is characterized by temporarily changing one connection strength at a time to determine its effect on system output relative to the desired target. That connection strength is then adjusted based on the effect, whereby the processor is taught the correct response to training examples connection by connection
Network of dedicated processors for finding lowest-cost map path
A method and associated apparatus are disclosed for finding the lowest cost path of several variable paths. The paths are comprised of a plurality of linked cost-incurring areas existing between an origin point and a destination point. The method comprises the steps of connecting a purality of nodes together in the manner of the cost-incurring areas; programming each node to have a cost associated therewith corresponding to one of the cost-incurring areas; injecting a signal into one of the nodes representing the origin point; propagating the signal through the plurality of nodes from inputs to outputs; reducing the signal in magnitude at each node as a function of the respective cost of the node; and, starting at one of the nodes representing the destination point and following a path having the least reduction in magnitude of the signal from node to node back to one of the nodes representing the origin point whereby the lowest cost path from the origin point to the destination point is found
Studies on the Radioactive Dating of the Lunar Surface Final Report
Remotely controlled rare gas analyzer with chemical reaction as energy source considered for radioactive dating of lunar surfac
Research in the development of an improved multiplier phototube Final report
Counting efficiency, noise factor measurement, dark noise, gain and counting rate, optical enhancemen
Rare gas measurements in meteorites and possible applications to the lunar surface
Meteorite history determined from rare gas composition - possible analysis of lunar surface histor
On-orbit cryogenic fluid transfer
A number of future NASA and DOD missions have been identified that will require, or could benefit from resupply of cryogenic liquids in orbit. The most promising approach for accomplishing cryogenic fluid transfer in the weightlessness environment of space is to use the thermodynamic filling technique. This approach involves initially reducing the receiver tank temperature by using several charge hold vent cycles followed by filling the tank without venting. Martin Marietta Denver Aerospace, under contract to the NASA Lewis Research Center, is currently developing analytical models to describe the on orbit cryogenic fluid transfer process. A detailed design of a shuttle attached experimental facility, which will provide the data necessary to verify the analytical models, is also being performed
Research in the development of an improved multiplier phototube
Parameters in analog /dc/ and digital /single electron pulse count/ modes of processing data from photomultiplier tube
Balanced Product Quantum Codes
This work provides the first explicit and non-random family of
LDPC quantum codes which encode logical qubits
with distance . The family is constructed by
amalgamating classical codes and Ramanujan graphs via an operation called
balanced product.
Recently, Hastings-Haah-O'Donnell and Panteleev-Kalachev were the first to
show that there exist families of LDPC quantum codes which break the
distance barrier. However, their
constructions are based on probabilistic arguments which only guarantee the
code parameters with high probability whereas our bounds hold unconditionally.
Further, balanced products allow for non-abelian twisting of the check
matrices, leading to a construction of LDPC quantum codes that can be shown to
have and that we conjecture to have linear distance .Comment: 23 pages, 11 figure
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