Graph Neural Network based Child Activity Recognition

TL;DR

This paper introduces a novel graph convolutional network approach for child activity recognition, demonstrating improved accuracy through transfer learning, feature extraction, and curriculum learning on small datasets.

Contribution

First to apply GCN to child activity recognition, analyzing transfer learning effects and proposing methods to enhance performance on limited data.

Findings

GCN-based model achieved around 50% accuracy on small datasets

Feature extraction and fine-tuning improved accuracy by 20-30%

Curriculum learning can enhance model performance

Abstract

This paper presents an implementation on child activity recognition (CAR) with a graph convolution network (GCN) based deep learning model since prior implementations in this domain have been dominated by CNN, LSTM and other methods despite the superior performance of GCN. To the best of our knowledge, we are the first to use a GCN model in child activity recognition domain. In overcoming the challenges of having small size publicly available child action datasets, several learning methods such as feature extraction, fine-tuning and curriculum learning were implemented to improve the model performance. Inspired by the contradicting claims made on the use of transfer learning in CAR, we conducted a detailed implementation and analysis on transfer learning together with a study on negative transfer learning effect on CAR as it hasn't been addressed previously. As the principal contribution, we were able to develop a ST-GCN based CAR model which, despite the small size of the dataset, obtained around 50% accuracy on vanilla implementations. With feature extraction and fine-tuning methods, accuracy was improved by 20%-30% with the highest accuracy being 82.24%. Furthermore, the results provided on activity datasets empirically demonstrate that with careful selection of pre-train model datasets through methods such as curriculum learning could enhance the accuracy levels. Finally, we provide preliminary evidence on possible frame rate effect on the accuracy of CAR models, a direction future research can explore.