Data Augmentation Strategies for Machine Learning Modelling of Compressive Strength of Biomedical Scaffolds
摘要
We address the problem of insufficient data for neural network regression modelling in the context of mechanical properties of 3D printed scaffolds. Experimental data corresponds to compressive strength of PLA scaffolds dependent of layer thickness, extrusion temperature and porosity. This paper aims to evaluate two data augmentation strategies based on a Gaussian Copula (GC) method and on a conditional tabular generative adversarial network (CTGAN) method. The results indicate that the GC method generates a more statistically similar data than the CTGAN method. A feed-forward neural network with fixed 3-8-1 architecture and Levenberg-Marquardt learning algorithm is used for regression using synthetic and real data from both methods and evaluated through the coefficient of determination (R) and mean square error (MSE). Both metrics point to a better regression performance of the GC method, with R-values above 80% and lower MSE values compared to lower R-values (less than 40%) and larger MSE values of the CTGAN method. The performance plots show a better stability of the network’s training-validation processes for data generated with the GC method.