Given a weighted graph and a partial node labeling, the graph classification problem consists in predicting the labels of all the nodes. In several application domains, from gene to social network analysis, the labeling is unbalanced: for instance positive labels may be much less than negatives. In this paper we present COSNet (COst Sensitive neural Network), a neural algorithm for predicting node labels in graphs with unbalanced labels. COSNet is based on a 2-parameter family of Hopfield networks, and consists of two main steps: (1) the network parameters are learned through a cost-sensitive optimization procedure; (2) a suitable Hopfield network restricted to the unlabeled nodes is considered and simulated. The reached equilibrium point induces the classification of the unlabeled nodes. The restriction of the dynamics leads to a significant reduction in time complexity and allows the algorithm to nicely scale with large networks. An experimental analysis on real-world unbalanced data, in the context of the genome-wide prediction of gene functions, shows the effectiveness of the proposed approach.
A neural network algorithm for semi-supervised node label learning from unbalanced data / M.Frasca, A. Bertoni, M. Re, G. Valentini. - In: NEURAL NETWORKS. - ISSN 0893-6080. - 43(2013), pp. 84-98.
|Titolo:||A neural network algorithm for semi-supervised node label learning from unbalanced data|
FRASCA, MARCO (Primo)
BERTONI, ALBERTO (Secondo)
RE', MATTEO (Penultimo)
VALENTINI, GIORGIO (Ultimo)
|Parole Chiave:||Hopfield neural networks; Learning from unbalanced data; Node label prediction; Semi-supervised learning in graphs|
|Settore Scientifico Disciplinare:||Settore INF/01 - Informatica|
|Progetto:||Pattern Analysis, Statistical Modelling and Computational Learning 2|
|Data di pubblicazione:||2013|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1016/j.neunet.2013.01.021|
|Appare nelle tipologie:||01 - Articolo su periodico|