Relaxed Dissimilarity-based Symbolic Histogram Variants for Granular Graph Embedding

Luca Baldini, Alessio Martino, Alessio Martino, Antonello Rizzi

2021

Abstract

Graph embedding is an established and popular approach when designing graph-based pattern recognition systems. Amongst the several strategies, in the last ten years, Granular Computing emerged as a promising framework for structural pattern recognition. In the late 2000’s, symbolic histograms have been proposed as the driving force in order to perform the graph embedding procedure by counting the number of times each granule of information appears in the graph to be embedded. Similarly to a bag-of-words representation of a text corpora, symbolic histograms have been originally conceived as integer-valued vectorial representation of the graphs. In this paper, we propose six ‘relaxed’ versions of symbolic histograms, where the proper dissimilarity values between the information granules and the constituent parts of the graph to be embedded are taken into account, information which is discarded in the original symbolic histogram formulation due to the hard-limited nature of the counting procedure. Experimental results on six open-access datasets of fully-labelled graphs show comparable performance in terms of classification accuracy with respect to the original symbolic histograms (average accuracy shift ranging from -7% to +2%), counterbalanced by a great improvement in terms of number of resulting information granules, hence number of features in the embedding space (up to 75% less features, on average).

Paper Citation

in Harvard Style

Baldini L., Martino A. and Rizzi A. (2021). Relaxed Dissimilarity-based Symbolic Histogram Variants for Granular Graph Embedding. In Proceedings of the 13th International Joint Conference on Computational Intelligence (IJCCI 2021) - Volume 1: NCTA; ISBN 978-989-758-534-0, SciTePress, pages 221-235. DOI: 10.5220/0010652500003063

in Bibtex Style

@conference{ncta21,
author={Luca Baldini and Alessio Martino and Antonello Rizzi},
title={Relaxed Dissimilarity-based Symbolic Histogram Variants for Granular Graph Embedding},
booktitle={Proceedings of the 13th International Joint Conference on Computational Intelligence (IJCCI 2021) - Volume 1: NCTA},
year={2021},
pages={221-235},
publisher={SciTePress},
organization={INSTICC},
doi={10.5220/0010652500003063},
isbn={978-989-758-534-0},
}

in EndNote Style

TY - CONF

JO - Proceedings of the 13th International Joint Conference on Computational Intelligence (IJCCI 2021) - Volume 1: NCTA
TI - Relaxed Dissimilarity-based Symbolic Histogram Variants for Granular Graph Embedding
SN - 978-989-758-534-0
AU - Baldini L.
AU - Martino A.
AU - Rizzi A.
PY - 2021
SP - 221
EP - 235
DO - 10.5220/0010652500003063
PB - SciTePress