Distributed Repair of Deep Neural Networks

Deep Neural Networks (DNNs) are applied in several safety-critical domains and their trustworthiness is of paramount importance. For example, DNNs used in autonomous driving as classifiers should not misclassify detected objects; however, since obtaining perfect accuracy is not possible, special attention should be given to the most critical cases, e.g., pedestrians. This has been confirmed by the consortium of our partners from the automotive domain that provided us with specific risk levels for different misclassifications. A recent approach to improve DNN performance is to localise DNN weights responsible for the misclassifications and then adjust (repair) them to improve the misclassifications. However, they under-perform when they need to consider multiple misclassifications, and they do not consider the risk levels of the different misclassifications. To tackle this, we propose DISTRREP, a distributed repair approach that first finds the best fixes for each critical misclassification, and then integrates them in a single repaired DNN model, by considering the risk levels. We assess DISTRREP over three DNN models and a dataset of autonomous driving images, by considering requirements specified by our industrial partners. Experiments show that DISTRREP is more effective than baseline approaches based on retraining, and other risk-unaware repair approaches.