1,542 research outputs found
Spaceborne memory organization, phase 1 Final report
Application of associative memories to data processing for future space vehicle
A ferrofluid based neural network: design of an analogue associative memory
We analyse an associative memory based on a ferrofluid, consisting of a
system of magnetic nano-particles suspended in a carrier fluid of variable
viscosity subject to patterns of magnetic fields from an array of input and
output magnetic pads. The association relies on forming patterns in the
ferrofluid during a trainingdphase, in which the magnetic dipoles are free to
move and rotate to minimize the total energy of the system. Once equilibrated
in energy for a given input-output magnetic field pattern-pair the particles
are fully or partially immobilized by cooling the carrier liquid. Thus produced
particle distributions control the memory states, which are read out
magnetically using spin-valve sensors incorporated in the output pads. The
actual memory consists of spin distributions that is dynamic in nature,
realized only in response to the input patterns that the system has been
trained for. Two training algorithms for storing multiple patterns are
investigated. Using Monte Carlo simulations of the physical system we
demonstrate that the device is capable of storing and recalling two sets of
images, each with an accuracy approaching 100%.Comment: submitted to Neural Network
Memory formation in matter
Memory formation in matter is a theme of broad intellectual relevance; it
sits at the interdisciplinary crossroads of physics, biology, chemistry, and
computer science. Memory connotes the ability to encode, access, and erase
signatures of past history in the state of a system. Once the system has
completely relaxed to thermal equilibrium, it is no longer able to recall
aspects of its evolution. Memory of initial conditions or previous training
protocols will be lost. Thus many forms of memory are intrinsically tied to
far-from-equilibrium behavior and to transient response to a perturbation. This
general behavior arises in diverse contexts in condensed matter physics and
materials: phase change memory, shape memory, echoes, memory effects in
glasses, return-point memory in disordered magnets, as well as related contexts
in computer science. Yet, as opposed to the situation in biology, there is
currently no common categorization and description of the memory behavior that
appears to be prevalent throughout condensed-matter systems. Here we focus on
material memories. We will describe the basic phenomenology of a few of the
known behaviors that can be understood as constituting a memory. We hope that
this will be a guide towards developing the unifying conceptual underpinnings
for a broad understanding of memory effects that appear in materials
Engineering study for a mass memory system for advanced spacecrafts Final report, 1 Dec. 1969 - 1 Jul. 1970
Mass memory system for advanced spacecraf
Spaceborne memory organization - Appendices Interim report
Computational requirements and information storage devices for unmanned spacecraft in advanced planetary exploration, 1975 - 198
Interference filters as nonlinear decision-making elements for three-spot pattern recognition and associative memories
Simple patterns consisting of three spots (V and Γ) have been recognized by dividing, shifting, and recombining
beams onto bistable ZnS interference filters. This experiment demonstrates AND-gate operation,
cascading, and a moderate amount of parallelism, but a laser power of several watts was required and the
response times were several milliseconds. An associative memory for fingerprint identification has been
constructed using a VanderLugt correlator and an interference filter as a reflective thresholding device
Data storage hierarchy systems for data base computers.
Thesis. 1979. Ph.D.--Massachusetts Institute of Technology. Alfred P. Sloan School of Management.MICROFICHE COPY AVAILABLE IN ARCHIVES AND DEWEY.Vita.Bibliography: p. 241-248.Ph.D
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