70 research outputs found
Design of Oscillatory Neural Networks by Machine Learning
We demonstrate the utility of machine learning algorithms for the design of
Oscillatory Neural Networks (ONNs). After constructing a circuit model of the
oscillators in a machine-learning-enabled simulator and performing
Backpropagation through time (BPTT) for determining the coupling resistances
between the ring oscillators, we show the design of associative memories and
multi-layered ONN classifiers. The machine-learning-designed ONNs show superior
performance compared to other design methods (such as Hebbian learning) and
they also enable significant simplifications in the circuit topology. We
demonstrate the design of multi-layered ONNs that show superior performance
compared to single-layer ones. We argue Machine learning can unlock the true
computing potential of ONNs hardware
Quantum Cellular Neural Networks
We have previously proposed a way of using coupled quantum dots to construct
digital computing elements - quantum-dot cellular automata (QCA). Here we
consider a different approach to using coupled quantum-dot cells in an
architecture which, rather that reproducing Boolean logic, uses a physical
near-neighbor connectivity to construct an analog Cellular Neural Network
(CNN).Comment: 7 pages including 3 figure
Experimental Demonstration of a Rowland Spectrometer for Spin Waves
We experimentally demonstrate the operation of a spin-wave Rowland
spectrometer. In the proposed device geometry, spin waves are coherently
excited on a diffraction grating and form an interference pattern that
spatially separates spectral components of the incoming signal. The diffraction
grating was created by focused-ion-beam irradiation, which was found to locally
eliminate the ferrimagnetic properties of YIG, without removing the material.
We found that in our experiments spin waves were created by an indirect
mechanism, by exploiting nonlinear resonance between the grating and the
coplanar waveguide. Our work paves the way for complex spin-wave optic devices
-- chips that replicate the functionality of integrated optical devices on a
chip-scale.Comment: 7 pages, 5 figures, presented at Joint European Magnetic Symposia
(JEMS) 202
Coupled-Oscillator Associative Memory Array Operation for Pattern Recognition
Operation of the array of coupled oscillators underlying the associative memory function is demonstrated for various interconnection schemes (cross-connect, star phase keying and star frequency keying) and various physical implementation of oscillators (van der Pol, phase-locked loop, spin torque). The speed of synchronization of oscillators and the evolution of the degree of matching is studied as a function of device parameters. The dependence of errors in association on the number of the memorized patterns and the distance between the test and the memorized pattern is determined for Palm, Furber and Hopfield association algorithms
On-Chip Electric Waves: An Analog Circuit Approach to Physical Uncloneable Functions
This paper proposes the use of Cellular Non-Linear Networks (CNNs) as physical uncloneable functions (PUFs). We argue that analog circuits offer higher security than existing digital PUFs and that the CNN paradigm allows us to build large, unclonable, and scalable analog PUFs, which still show a stable and repeatable input--output behavior.
CNNs are dynamical arrays of locally-interconected cells, with a cell dynamics that depends upon the interconnection strengths to their neighbors. They can be designed to evolve in time according to partial differential equations.
If this equation describes a physical phenomenon, then the CNN can simulate a complex physical system on-chip. This can be exploited to create electrical PUFs with high relevant structural information content.
To illustrate our paradigm at work, we design a circuit that directly emulates nonlinear wave propagation phenomena in a random media. It effectively translates the complexity of optical PUFs into electrical circuits. %&, leading to better practicality, while maintaining or even improving the security properties of their optical counterparts
- …