Publication Details
Title: Labeling RAAM
Author: A. Sperduti
Group: ICSI Technical Reports
Date: May 1993
PDF: ftp://ftp.icsi.berkeley.edu/pub/techreports/1993/tr-93-029.pdf
Overview:
In this report we propose an extension of the Recursive Auto-Associative Memory (RAAM) by Pollack. This extension, the Labeling RAAM (LRAAM), is able to encode labeled graphs with cycles by representing pointers explicitly. A theoretical analysis of the constraints imposed on the weights by the learning task under the hypothesis of perfect learning and linear output units is presented. Cycles and confluent pointers result to be particularly effective in imposing constraints on the weights. Some technical problems encountered in the RAAM, such as the termination problem in the learning and decoding processes, are solved more naturally in the LRAAM framework. The representations developed for the pointers seem to be robust to recurrent decoding along a cycle. Data encoded in a LRAAM can be accessed by pointer as well as by content. The direct access by content can be achieved by transforming the encoder network of the LRAAM in a Bidirectional Associative Memory (BAM). Different access procedures can be defined according to the access key. The access procedures are not wholly reliable, however they seem to have a high likelihood of success. A geometric interpretation of the decoding process is given and the representations developed in the pointer space of a two hidden units LRAAM are presented and discussed. In particular, the pointer space results to be partitioned in a fractal-like fashion. Some effects on the representations induced by the Hopfield-like dynamics of the pointer decoding process are discussed and an encoding scheme able to retain the richness of representation devised by the decoding function is outlined. The application of the LRAAM model to the control of the dynamics of recurrent high-order networks is briefly sketched as well.
Bibliographic Information:
ICSI Technical Report TR-93-029
Bibliographic Reference:
A. Sperduti. Labeling RAAM. ICSI Technical Report TR-93-029, May 1993
Author: A. Sperduti
Group: ICSI Technical Reports
Date: May 1993
PDF: ftp://ftp.icsi.berkeley.edu/pub/techreports/1993/tr-93-029.pdf
Overview:
In this report we propose an extension of the Recursive Auto-Associative Memory (RAAM) by Pollack. This extension, the Labeling RAAM (LRAAM), is able to encode labeled graphs with cycles by representing pointers explicitly. A theoretical analysis of the constraints imposed on the weights by the learning task under the hypothesis of perfect learning and linear output units is presented. Cycles and confluent pointers result to be particularly effective in imposing constraints on the weights. Some technical problems encountered in the RAAM, such as the termination problem in the learning and decoding processes, are solved more naturally in the LRAAM framework. The representations developed for the pointers seem to be robust to recurrent decoding along a cycle. Data encoded in a LRAAM can be accessed by pointer as well as by content. The direct access by content can be achieved by transforming the encoder network of the LRAAM in a Bidirectional Associative Memory (BAM). Different access procedures can be defined according to the access key. The access procedures are not wholly reliable, however they seem to have a high likelihood of success. A geometric interpretation of the decoding process is given and the representations developed in the pointer space of a two hidden units LRAAM are presented and discussed. In particular, the pointer space results to be partitioned in a fractal-like fashion. Some effects on the representations induced by the Hopfield-like dynamics of the pointer decoding process are discussed and an encoding scheme able to retain the richness of representation devised by the decoding function is outlined. The application of the LRAAM model to the control of the dynamics of recurrent high-order networks is briefly sketched as well.
Bibliographic Information:
ICSI Technical Report TR-93-029
Bibliographic Reference:
A. Sperduti. Labeling RAAM. ICSI Technical Report TR-93-029, May 1993