Hierarchical Neural Networks for the Storage of Correlated Memories

Deshpande, Varsha and Dasgupta, Chandan (1991) Hierarchical Neural Networks for the Storage of Correlated Memories. In: Journal of Statistical Physics, 64 (3-4). pp. 755-579.

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Abstract

A class of hierarchical neural network models introduced by Dotsenko for the storage and associative recall of strongly correlated memories is studied analytically and numerically. In these models, patterns stored in higher levels of the hierarchy represent generalized categories and those stored in lower levels describe finer details. We first show that the models originally proposed by Dotsenko have a serious flaw: they are not able to detect or correct errors in categorization which may be present in the input. We then describe three different models which attempt to overcome this shortcoming of the original models. In the first model, the interaction between different levels of the hierarchy has the form of an external field conjugate to memories stored in the lower level. In the second model, a three-spin interaction term is included in addition to the usual binary interactions of the Hopfield type. The third model makes use of a time delay mechanism to induce, if necessary, transitions between memory states and their complements. Detailed analytical and numerical studies of the performance of these models are presented. Our analysis shows that all three models are able to detect and also to correct in varying degrees any error in categorization that may be present in the input pattern.

Item Type:	Journal Article
Publication:	Journal of Statistical Physics
Publisher:	Springer Netherlands
Additional Information:	Copyright of this article belongs to Springer Netherlands.
Keywords:	Neural networks;Associative memory;Hierarchically correlated patterns;Statistical mechanics of Ising systems; Replica formalism;Numerical simulation.
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	07 Sep 2006
Last Modified:	19 Sep 2010 04:31
URI:	http://eprints.iisc.ac.in/id/eprint/8448

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