73,307 research outputs found
Adaptive Resonance Associative Map: A Hierarchical ART System for Fast Stable Associative Learning
This paper introduces a new class of predictive ART architectures, called Adaptive Resonance Associative Map (ARAM) which performs rapid, yet stable heteroassociative learning in real time environment. ARAM can be visualized as two ART modules sharing a single recognition code layer. The unit for recruiting a recognition code is a pattern pair. Code stabilization is ensured by restricting coding to states where resonances are reached in both modules. Simulation results have shown that ARAM is capable of self-stabilizing association of arbitrary pattern pairs of arbitrary complexity appearing in arbitrary sequence by fast learning in real time environment. Due to the symmetrical network structure, associative recall can be performed in both directions.Air Force Office of Scientific Research (90-0128
Phase Clocks for Transient Fault Repair
Phase clocks are synchronization tools that implement a form of logical time
in distributed systems. For systems tolerating transient faults by self-repair
of damaged data, phase clocks can enable reasoning about the progress of
distributed repair procedures. This paper presents a phase clock algorithm
suited to the model of transient memory faults in asynchronous systems with
read/write registers. The algorithm is self-stabilizing and guarantees accuracy
of phase clocks within O(k) time following an initial state that is k-faulty.
Composition theorems show how the algorithm can be used for the timing of
distributed procedures that repair system outputs.Comment: 22 pages, LaTe
Randomization Adaptive Self-Stabilization
We present a scheme to convert self-stabilizing algorithms that use
randomization during and following convergence to self-stabilizing algorithms
that use randomization only during convergence. We thus reduce the number of
random bits from an infinite number to a bounded number. The scheme is
applicable to the cases in which there exits a local predicate for each node,
such that global consistency is implied by the union of the local predicates.
We demonstrate our scheme over the token circulation algorithm of Herman and
the recent constant time Byzantine self-stabilizing clock synchronization
algorithm by Ben-Or, Dolev and Hoch. The application of our scheme results in
the first constant time Byzantine self-stabilizing clock synchronization
algorithm that uses a bounded number of random bits
Towards Fully Passive Time-Bin Quantum Key Distribution over Multi-Mode Channels
Phase stabilization of distant quantum time-bin interferometers is a major
challenge for quantum communication networks, and is typically achieved by
exchanging optical reference signals, which can be particularly challenging
over free-space channels. We demonstrate a novel approach using reference frame
independent time-bin quantum key distribution that completely avoids the need
for active relative phase stabilization while simultaneously overcoming a
highly multi-mode channel without any active mode filtering. We realized a
proof-of-concept demonstration using hybrid polarization and time-bin entangled
photons, that achieved a sustained asymptotic secure key rate of greater than
0.06 bits/coincidence over a 15m multi-mode fiber optical channel. This is
achieved without any mode filtering, mode sorting, adaptive optics, active
basis selection, or active phase alignment. This scheme enables passive
self-compensating time-bin quantum communication which can be readily applied
to long-distance links and various wavelengths, and could be useful for a
variety of spatially multi-mode and fluctuating channels involving rapidly
moving platforms, including airborne and satellite systems.Comment: 12 pages, 4 Figures, 1 Tabl
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